3. Surgical principles III – Extraction healing- Fresh Extraction Socket Preservation Techniques

Advanced Surgery and Implant Literature Review

Rapid Search Terms

References

Book Chapter

  • Management of Extraction Sockets (CH 12) pp 512-607. Zuhr and Hurzeler. Plastic-Esthetic Periodontal and Implant Surgery: A Microsurgical Approach. 2012, Quintessence Publishing.

Journals

Healing of Extraction Sockets

  1. Schropp L, Wenzel A, Kostopoulos L, Karring T. Bone healing and soft tissue contour changes following single-tooth extraction: a clinical and radiographic 12-month prospective study. Int J Periodontics Restorative Dent. 2003 Aug;23(4):313-23.
  2. Araújo MG, Lindhe J. Dimensional ridge alterations following tooth extraction. An experimental study in the dog. J Clin Periodontol. Feb;32(2):212-8; 2005
  3. Elian N, Cho SC, Froum S, Smith RB, Tarnow DP. A simplified socket classification and repair technique. Pract Proced Aesthet Dent. Mar;19(2):99-104; 2007

Ridge Preservation Options

  1. Nevins M, Camelo M, De Paoli S, Friedland B, Schenk RK, Parma-Benfenati S, Simion M, et al. A study of the fate of the buccal wall of extraction sockets of teeth with prominent roots. Int J Periodontics Restorative Dent. Feb;26(1):19-29; 2006
  2. Braut et al. Thickness of the anterior maxillary facial bone wall-a retrospective radiographic study using cone beam computed tomography. Int J Periodontics Restorative Dent 2011; 31: 125-131.
  3. Burchardt H et al. The biology of bone graft repair. Clin Orthop Relat Res. (1983)
  4. Heggeler JM, Slot DE, Van der Weijden GA. Effect of socket preservation therapies following tooth extraction in non-molar regions in humans: a systematic review. Clin Oral Implants Res. 2011 Aug;22(8):779-88.
  5. Darby I, Chen ST, Buser D. Ridge preservation techniques for implant therapy. Int J Oral Maxillofac Implants. 2009;24 Suppl:260-71. Review.
  6. Wang HL, Tsao YP. Mineralized bone allograft-plug socket augmentation: rationale and technique. Implant Dent. Mar;16(1):33-41; 2007
  7. Sclar AG. Strategies for management of single-tooth extraction sites in aesthetic implant therapy. J Oral Maxillofac Surg. Sep;62(9 Suppl 2):90-105;2004
  8. Lasella JM, Greenwell H, Miller RL, Hill M, Drisko C, Bohra AA, Scheetz JP. Ridge preservation with freeze-dried bone allograft and a collagen membrane compared to extraction alone for implant site development: a clinical and histologic study in humans. J Periodontol. 74(7):990-9; 2003
  9. Wood RA, Mealey BL. Histologic comparison of healing after tooth extraction with ridge preservation using mineralized versus demineralized freeze-dried bone allograft. J Periodontol 2012; 83:329-336.
  10. Fiorellini JP, Howell TH, Cochran D, et al. Randomized study evaluating recombinant human bone morphogenetic protein-2 for extraction socket augmentation. J Periodontol. 2005 Apr;76(4):605-13
  11. Farina R, Bressan E, et al. Plasma rich in growth factors in human extraction sockets: a radiographic and histomorphometric study on early bone deposition. Clin Oral Implants Res. 2013 Dec;24(12):1360-8.
  12. Coomes AM, Mealey BL, et al. Buccal Bone Formation After Flapless Extraction: A Randomized Controlled Clinical Trial Comparing Recombinant Human Bone Morphogenetic Protein-2/Absorbable Collagen Carrier and Collagen Sponge Alone. J Periodontol. 2013 Jul 4.
  13. Carbonell JM, Martín IS, et al. High-density polytetrafluoroethylene membranes in guided bone and tissue regeneration procedures: a literature review. Int J Oral Maxillofac Surg. 2014 Jan;43(1):75-84.
  14. Nevins#nevins2M, Mellonig JT, et al. Implants in regenerated bone: long-term survival. Int J Periodontics Restorative Dent. 1998 Feb;18(1):34-45.
  15. Barone A, Orlando B, et al. A randomized clinical trial to evaluate and compare implants placed in augmented versus non-augmented extraction sockets: 3-year results. J Periodontol. 2012 Jul;83(7):836-46.

Implant success in grafted sites

  1. Marconcini S et al. Clinical outcomes of implants placed in ridge-preserved versus nonpreserved sites: A 4-year randomized clinical trial. Clin Implant Dent Related Res. 2018 Dec 20(6):906-914
  2. Tran DT et al. Dental implants placed in grafted and nongrafted bone: a retrospective university setting. Int J Oral Maxillofac Implants. 2016 Mar-Apr;31(2):310-7.

Socket Shield

  1. Gharpure AS, Bhatavadekar NB. Current evidence on the socket-shield technique: a systematic review. J Oral Implantol. 2017 Oct;43(5):395-403.
  2. Nevins ML, Langer L, Schupbach. Late dental implant failures associated with retained root fragments: case reports with histologic and SEM analysis. Int J Perio Rest Dent. 2018;38(1)

Early and Immediate Placement

  1. Buser D, et al. Implant placement post extraction in esthetic single tooth sites: when immediate, when early, when late? Periodontol 2000. 2017 Feb;73(1):84-102.
  2. Schropp L, Wenzel A. Timing of single implant placement and long-term observation of marginal bone levels. Eur J Oral Implantol. 2016;9 Suppl 1:S107-22
  3. Chen S, Buser D. Esthetic Outcomes Following Immediate and Early Implant Placement in the Anterior Maxilla—A Systematic Review. Int J Oral Maxillofac Implants. 2014 Jan-Feb;29(supplement):186-215.
  4. Gakonyo, et al. Cone Beam Computed Tomography Assessment of the Buccal Bone Thickness in Anterior Maxillary Teeth: Relevance to Immediate Implant placement. Int J Oral Maxillofac Implants. 2018. July/Aug 33(4):880-887.
  5. Bassir SH et al. Outcome of early dental implant placement versus other dental implant placement protocols: a systemic review and meta-analysis. J Peridontol 2018 Nov 5 epub ahead of print
  6. Sanz M, Lindhe J, Alcaraz J, Sanz-Sanchez I, Cecchinato D. The effect of placing a bone replacement graft in the gap at immediately placed implants: a randomized clinical trial. Clin Oral Implants Res. 2016 Jun 7.

Bone remodeling after Implant placement

  1. Lee CT, Chiu TS, et al. Alterations of the Bone Dimension Following Immediate Implant Placement into Extraction Socket: Systematic Review and Meta-Analysis. J Clin Periodontol. 2014 Jun 3.
  2. Mazzocco F et al. Bone volume changes after immediate implant placement with or without flap elevation. Clin Oral Implants Res. 2017 Apr;28(4): 495-501.

Placement into infected sites

  1. Chrcanovic BR, Martins MD, Wennerberg A. Immediate Placement of Implants into Infected Sites: A Systematic Review. Clin Implant Dent Relat Res. 2015 Jan;17 suppl1:e1-16.
  2. Zuffetti F, et al. Post-extraction implant placement into infected versus non-infected sites: a multicenter retrospective clinical study. Clin Implant Dent Relat Res 2017 Oct;19)5):833-40.
  3. Corbella S, Taschieri S, Tsesis I, Massimo DF. Postextraction implant in sites with endodontic infection as an alternative to endodontic retreatment: a review of literature. J Oral Implantol. 2012 May 22.

Abstracts:

Topic:tooth extraction healing

Authors: Schropp L

TitleBone healing and soft tissue contour changes following single-tooth extraction: a clinical and radiographic 12-month prospective study

Source:Int J Periodontics Restorative Dent. 2003 Aug;23(4):313-23.

Type:Clinical

P: to assess bone formation in the alveolus and changes of the contour of the alveolar process following single-tooth extraction. a clinical and radiographic 12-month prospective study

M&M: 46 pts, mean age 45 years, referred for extraction of a maxillary or mandibular premolar or molar followed by single tooth implant treatment. 11 maxillary and 10 mandibular premolars and 9 maxillary and 16 mandibular molars were included in the study. Clinical and radiographic evaluation of the extraction site was carried out at baseline 0, 3, 6 and 12 months following the extraction. Standardized X-rays were taken.

R/C/BL

  • Widthof alveolar ridge reduced by 50% (5-7mm loss) during 12 month observation period
  • Larger reduction seen in molar regions, more in mandible
  • 2/3 of this reduction occurs within first 3 months
  • Soft tissue height changes approximately 1mm or less

Topic: Extraction

Authors: Araújo MG, Lindhe J.

Title: Dimensional ridge alterations following tooth extraction. An experimental study in the dog. Source: J Clin Periodontol. 2005 Feb;32(2):212-8.

Type: Experimental study

Rating: Good

Keywords: Extraction

Purpose: To study dimensional alterations of the alveolar ridge that occurred following tooth extraction as well as processes of bone modelling and remodelling associated with such change.

Method: 12 mongrel dogs were included in the study. Sulcular incision performed on the 3rd and 4th premolars. Small buccal and lingual full thickness flaps were elevated. Teeth were hemisected. The distal roots were removed. The extraction sites were covered with the mobilized gingival tissue. The dogs were sacrificed at 1, 2, 4 and 8 weeks of healing and tissue blocks containing the extraction socket were dissected. The sections were examined in the microscope.

Results: The most dimensional alterations occurred during the first 8 weeks following the extraction of mandibular premolars. At this interval there was a marked osteoclastic activity resulting in resorption of the crestal region of both the buccal and the lingual bone wall. The reduction of the height of the walls was more pronounced at the buccal than at the lingual aspect of the extraction socket. The height reduction was accompanied by a ‘‘horizontal’’ bone loss that was caused by osteoclasts present in lacunae on the surface of both the buccal and the lingual bone wall. The resorption of the buccal/lingual walls of the extraction site occurred in two overlapping phases. Phase 1: the bundle bone was resorbed and replaced with woven bone. Since the crest of the buccal bone wall was comprised solely of bundle this modelling resulted in substantial vertical reduction of the buccal crest. Phase 2 included resorption that occurred from the outer surfaces of both bone walls. The reason for this additional bone loss is presently not understood.

Conclusion: The resorption of the buccal/lingual walls of the extraction site occurred in two overlapping phases. Most of this alterations occurred during the early phase, at 8 weeks post-extraction.

Topic:Ridge preservation


Authors:Nevins M, Camelo M, De Paoli S, Friedland B, Schenk RK, Parma-Benfenati S, Simion M

Title:A study of the fate of the buccal wall of extraction sockets of teeth with prominent roots.
Source: Int J Periodontics Restorative Dent. Feb;26(1):19-29; 2006

Type:Review

Rating:Good

Keywords:

Purpose:To determine the fate of thin buccal bone encasing the prominent roots of maxillary anterior teeth following extraction

Methods: 9 patients underwent extraction of 36 maxillary anterior teeth. 19 were grafted with Bio-OSS and 17 were not grafted at all. All extraction sockets were covered with soft tissue at the end of the surgery. CBCTs were taken following extraction and again at 30 and 90 days post extraction to assess the buccal plate healing. Results were assessed by an independent radiologist. 6 mm crest width was considered sufficient for an implant.

R:Sites grafted with Bio-Oss demonstrated a loss of less than 20% of the buccal plate in 79% of the test sites. Control sockets in contrast had 71% lose more than 20% of the buccal plate.Conclusion:Bio-Oss treated sites had significantly more retention of the buccal plate. A patient has a significant benefit from receiving grafting materials at the time of extraction. It seems prudent to introduce an osteoconductive substance into the extraction sockets of teeth with prominent roots to avoid loss of buccal plate and the resulting compromises in implant treatment.

 

Topic: Cone Beam Computed Tomography


Authors: Braut V, Bornstein MM, Belser U, Buser D.

Title: Thickness of the anterior maxillary facial bone wall-a retrospective radiographic study using cone beam computed tomography.

Source: Int J Periodontics Restorative Dent. 2011 Apr;31(2):125-31.

Type: Retrospective Study

Rating: Good

Purpose: To analyze the thickness of the facial bone wall at teeth in the anterior maxilla based on cone beam computed tomography (CBCT) images, since this anatomical structure is important for the selection of an appropriate treatment approach in patients undergoing post extraction implant placement.

Method: A total of 125 CBCT scans met the inclusion criteria, resulting in a sample size of 498 teeth. The thickness of the facial bone wall in the respective sagittal scans was measured perpendicular to the long axis of the tooth at two locations: at the crest level (4 mm apical to the cementoenamel junction; MP1) and at the middle of the root (MP2).

Results: No existing bone wall was found in 25.7% of all teeth at MP1 and in 10.0% at MP2. The majority of the examined teeth exhibited a thin facial bone wall (< 1 mm; 62.9% at MP1,.1% at MP2). A thick bone wall (⋝ 1 mm) was found in only 11.4% of all examined teeth at MP1 and 9.8% at MP2. There was a statistically significant decrease in facial bone wall thickness from the first premolars to the central incisors. The facial bone wall in the crestal area of teeth in the anterior maxilla was either missing or thin in roughly 90.0% of patients. Both a missing and thin facial wall require simultaneous contour augmentation at implant placement because of the well-documented bone resorption that occurs at a thin facial bone wall following tooth extraction.

Conclusion: Radiographic analysis of the facial bone wall using CBCT prior to extraction is recommended for selection of the appropriate treatment approach.

Topic:Bone repair with grafting


Authors: Burchardt H et al

Title:The biology of bone graft repair

Source:Clinical Orthopaedics & Related Research, Vol 174 page 28-37,April 1983

Type:Histological study

Rating: Good

Keywords:none

Purpose: To describe biology of bone repair by presenting general information on the microscropy and correlative biomechanics of autograft repair, biological aspects of allograft repair and alternatives when autogenous bone is insufficient

Discussion:

The process of bone graft incorporation is a function of the recipient bed and depends on close contact with the donor tissue, time sequences, and the equilibrium of the following interdependent processes: 1) proliferation of osteoprogenitor cells, 2) differentiation of osteoblasts, 3) osteoinduction, 4) osteoconduction, and 5) biomechanical properties of the graft. Incorporation is defined as the process of a complex of necrotic old bone with viable new bone. The process of capillary ingrowth, perivascular issue, and osteoprogenitor cells from the recipient bed into the graft is called osteoconduction. It occurs within a framework of non biologic materials and nonviable biologic materials. In viable bone grafts, osteocondition is facilitated by osteoinductive processes and therefore occurs more rapidly than in nonviable or nonbiologic materials.

Fresh Autograft repair:

Cancellous grafts are used primarily as a means to fill small defects, whereas segments of cortical bone are used primarily as supportive struts. During the first two weeks, both cancellous and cortical autogenous materials have similar histological features.

Cancellous and cortical autografts histologically have three differences:

1) Cancellous grafts are revascularized more rapidly and completely than cortical grafts

2) Cancellous bone substitutions initially involves an appositional bone formation phase, followed by a resorptive phase, whereas cortical grafts undergo a reverse creeping substitution process;

3) Cancellous grafts tend to repair completely with time, whereas cortical grafts remain as admixtures of necrotic and viable bone.

Physiologic skeletal metabolic factors influence the rate, amount, and completeness of bone repair and graft incorporation. The mechanical strengths of cancellous and cortical grafts are correlated with their respective repair processes: cancellous grafts tend to be strengthened first, whereas cortical grafts are weakened. Bone allografts are influenced by the same immunologic factors as other tissue grafts. Fresh bone allografts may be rejected by the host’s immune system. The histoincompatibility antigens of bone allografts are presumably the proteins or glycoproteins on cell surfaces. The matrix proteins may or may not elicit graft rejection. The rejection of a bone allograft is considered to be a cellular rather than a humoral response, although the humoral component may play a part. The degree of the host response to an allograft may be related to the antigen concentration and total dose. The rejection of a bone allograft is histologically expressed by the disruption of vessels, an inflammatory process including lymphocytes, fibrous encapsulation, ad peripheral graft resorption.

Topic:Ridge augmentation


Authors: Heggler Ten et al

Title:Effect of socket preservation therapies following tooth extraction in non-molar regions in humans: a systematic review

Source:Clinical oral implants research 22, no. 8 (2011): 779-788. doi: 10.1111/j.1600-0501.2010.02064.x

Type:Review

Rating: Fair

Keywords:bone loss, bone resorption, dimensional height and width changes, post-extraction socket, socket augmentation, socket preservation, systematic review, tooth extraction

Objective:To assess, based on the existing literature, the benefit of socket preservation therapies in patients with a tooth extraction in the anterior or premolar region as compared with no additional treatment with respect to bone level.

Material and methods: MEDLINE-PubMed and the Cochrane Central Register of controlled trials

(CENTRAL) were searched till June 2010 for appropriate studies, which reported data concerning the dimensional changes in alveolar height and width after tooth extraction with or without additional treatment like bone fillers, collagen, growth factors or membranes.

Results:Independent screening of the titles and abstracts of 1918 MEDLINE-PubMed and 163

Cochrane papers resulted in nine publications that met the eligibility criteria. In natural healing after extraction, a reduction in width ranging between 2.6 and 4.6mm and in height between 0.4 and 3.9mm was observed. With respect to socket preservation, the freeze-dried bone allograft group performed best with a gain in height, however, concurrent with a loss in width of 1.2mm.

Conclusion:Data concerning socket preservation therapies in humans are scarce, which does not allow any firm conclusions. Socket preservation may aid in reducing the bone dimensional changes following tooth extraction. However, they do not prevent bone resorption because, depending on the technique, on the basis of the included papers one may still expect a loss in width and in height.

Discussion:Use of regenerative biomaterial, growth factors, alternatives to ridge preservation (immediate implant placement) may be beneficial in preserving the ridge and reducing further bone loss.

Topic:Ridge Preservation


Authors: Darby I,

Title: Source: Int J Oral Maxillofac Implants. 2009;24 Suppl:260-71.

Type:review

Rating: good

Keywords:dental implants, extraction, grafting, ridge preservation, socket

P:A review of literature to evaluate the techniques and outcomes of post-ext ridge preservation (RP) and the efficacy of these procedures in implant placement.

M&M:A MEDLINE/PubMed search was conducted among articles from 1999 to March 2008, randomized clinical trials, controlled clinical trials, and pros/retrospective studies. Search lead to 37 human studies;

R:

  • Materials used:

– Graft material: DFDBA, DBBM= most used

Others: autologous bone, bioactive glass, hydroxyapatite, calcium sulphate, solvent preserved cancellous allograft and biocoral

– Membranes: e-PTFE and collagen membranes = most used

Others: polylactic/polyglycolic, titanium reinforced, acellular dermal matrix graft (ADMG)

  • Augmentation methods: 9 different methods were identified;
  • Most Common: graft covered by membrane and flap advancement to achieve primary closure
  • Second most common: coronal advancement of flap without membrane
  • flap was used for all techniques w/ a membrane but not for all procedures with graft or sponge
  • Outcomes of RP:
  • Graft vs. Clot alone: all showed significantly better maintenance of ridge width compared to healing by clot alone. reported less change in soft tissue thickness vs. control sites
  • Different Grafting Materials: slight differences between grafting materials
  • Primary Closure: primary closure was hard to assess due to diversity of soft tissue closure techniques used
  • Antibiotics Use: 26 of papers used ABX either during or after procedure
  • Implant Placement: non-grafted sites needed augmentation procedures at time of placement

C:

  • Ridge preservation procedures are effective in limiting horizontal and vertical ridge alterations in post-ext sites
  • RP is accompanied by varying degrees of bone formation and residual graft materials in the ext socket. This depends on the materials and techniques used.
  • There is no evidence to support the superiority of one technique over another.
  • The use of membranes requires soft tissue coverage to optimize treatment outcomes. Exposure of membranes may lead to compromised results. e-PTFE membranes that become exposed ae more problematic than collagen membranes.
  • Primary closure is not always necessary.
  • Long-term data on stability of the ridge and implant survival and success are limited.
  • There are no data on esthetic outcomes.
  • There is no conclusive evidence showing that RP improves the ability to place implant.

BL:RP is effective in limiting horizontal and vertical ridge alterations in post-ext sites but there is no conclusive evidence that RP improves the ability to place implants.

Topic:Ridge Preservation


Author:Elian N, Cho SC

Title:A Simplified Socket Classification and Repair Technique

Source:Pract Proced Aesthet Dent. Mar;19(2):99-104; 2007

Type:Procedure discussion

Rating: Good

Keywords:extraction socket, buccal plate, Type II socket, noninvasive

Purpose:To present a new, simple classification of extraction sockets. To introduce an easy non-invasive approach to the grafting of sockets when soft tissue is present, but the buccal plate is partially or totally missing after extraction.

Classification of Extraction Sockets:

Type 1: The facial soft tissue and buccal plate of bone are at normal levels in relation to the cementoenamel junction of the pre-extracted tooth and remain intact post extraction

  • Most predictable to graft, especially if biotype is “thick, flat”

Type 2: Facial soft tissue is present, but the buccal plate is partially missing following extraction of the tooth

  • Important to properly diagnose, if treated as Type 1, recession will occur.

Type 3: The facial soft tissue and the buccal plate of bone are both reduced after tooth extraction

  • Will require stage approach for soft and hard tissue development

The key factor to determining the quality of the socket is the presence or absence of the buccal hard and soft tissue.

Socket Repair Technique for Type II Sockets

  1. Atraumatic extraction
  2. The socket is debrided with surgical curettes. A finger should be placed over buccal tissue to prevent perforation of soft tissue when curetting the buccal part of socket
  3. A resorbable collagen membrane is contoured into a modified V-Shape. The narrow part of the membrane is placed into the socket and should be wide enough to extend laterally past the defect in the buccal wall. The wider part of the membrane should be trimmed and be able to cover the opening of the socket following grafting
  4. Membrane is positioned into the socket lining the buccal tissues. The socket is then filled with a bone graft, ideally the graft should be compressed into the socket and remain in place. Ideal graft=small-particle, mineralized cancellous freeze-dried bone allograft (0.25mm to 1mm)
    1. Compresses well, slowly resorbs, helps keep the shape of the socket
  5. Top part of membrane is extended over the opening and sutured with two or three 5-0 resorbable sutures to the palatal tissue. No sutures are placed in the buccal tissue

Justification for this Technique

  • Minimally invasive and because no flap is reflected or advanced coronally, there is no change in the MGJ position
  • Placing the membrane inside the socket, the Periosteum is not detached from the remaining buccal plate.
  • Placing membrane in socket before the graft allows for particle containment and maintains the soft tissue morphology.

BL:This minimally invasive socket repair technique has the advantage of being flapless, not distorting the buccal and interproximal tissue contours, preserving the height of the MGJ, and allowing the reformation of the buccal plate of bone. Comparison of bone levels prior to and following this treatment protocol should be a goal of future studies.

Topic: Socket Grafting
Authors: Wang H, Tsao Y.

Title: Mineralized Bone Allograft-plug Socket Augmentation: Rationale and Technique

Source: Implant Dent. Mar;16(1):33-41; 2007

Type: Clinical

Rating: Good

Keywords: Allograft, mineralized bone, extraction socket, bone regeneration

PURPOSE:To present the solvent-preserved, mineralized bone allograft-plug (Puros) for predictable socket augmentation instead of bovine hydroxyapatite bone graft (Bio-Oss), which leads to remaining hydroxyapatite crystals after 4 months of healing.

METHODS:Following atraumatic extraction and profuse bleeding is achieved with curettes or a round bur, solvent-preserved mineralized cancellous allograft (Puros) was hydrated with normal saline (or sterile water). Graft was then placed in socket and condensed to 1-2 mm below the bone level. Bioabsorbable collagen wound dressing material (CollaPlug) was gently packed on top of the bone graft material. A cross-mattress suture with 4-0 Vicryl was used on top of the collagen to achieve site stability. POI: Rinse bid with warm salt water for first two weeks, then switch to bid with chlorhexidine for 2 more weeks. Abx if indicated by current infection.

RESULTS: 2 weeks post-surgery the sockets showed uneventful healing and almost complete soft tissue coverage over the extraction site. Implant placement or stage II surgery can usually be performed at 4 months after treatment. RL persisting for more than 4 months are indicative of inadequate graft incorporation, frequently requiring an additional procedure for debridement of the graft particles and possible a new grafting procedure.

DISCUSSION: Allogenic bone graft materials have been promoted because of their availability and biologic activity compared to xenograft graft materials. While the graft by itself should be able to promote bone ingrowth, the use of a collagen plug has been shown to not only protect the graft but also induce clot formation and would stabilization.

CONCLUSION/BL: The mineralized bone allograft-plug is a suitable and predictable technique for socket augmentation to promote bone regeneration and preserve the alveolar ridge.

Topic: Socket management


Authors: Sclar AG. Strategies for management of single-tooth extraction sites in aesthetic implant therapy. J Oral Maxillofac Surg. Sep;62(9 Suppl 2):90-105;2004

Purpose: The purpose of this article is to provide information regarding the diagnosis and treatment planning as well as surgical and prosthetic management of patients faced with removal of a single tooth in an area of high aesthetic importance.

The author has reflected on systematic patient evaluation in terms of medical and dental history. And recommended special treatment planning considerations in relation to tooth malposition, periodontal bio-type, vertical maxillary deficiency, and compromised bone height or width on adjacent dentition.

The author has described the rational and details of performing the Bio-Col site preservation technique at the time of tooth removal. Its primary objective is either to preserve the osseous anatomy and scalloped soft tissue architecture in conjunction with immediate implant placement or to maintain the volume of reconstructive soft-tissue envelope and positive soft tissue architecture when subsequent site-development procedures will be unavoidable. The technique consists of atraumatic extraction of the tooth to be replaced, followed by grafting with Bio-Oss (porous bone grafting material) and isolation with an absorbable collagen membrane to promote guided bone regeneration without incorporating a flap. And the final soft tissue architecture can be maintained by using anatomic healing or custom tooth form healing abutments.

The author has developed a classification system alveolar ridge defects in aesthetic areas based on the volume and nature of the defect. Correlation of treatment options with specific defect types simplifies the selection and sequencing of indicated site-development procedures

  1. Small volume soft tissue defects are corrected by subepithelial C.T grafts at implant placement.
  2. large-volume soft tissue aesthetic ridge defects are usually corrected with several subepithelial connective tissue grafts before implant placement.
  3. Small-volume hard tissue defects (fenestrations) that do not jeopardize the buccal alveolar crest are usually corrected with guided bone-regeneration procedures performed simultaneously with the placement of a submerged or nonsubmerged implant.
  4. Large-volume hard tissue aesthetic ridge defects prevent ideal implant positioning and therefore are always reconstructed in stages using autogenous corticocancellous block and particulate cancellous bone grafts.
  5. Small-volume combination hard and soft tissue aesthetic ridge defects are often camouflaged with soft tissue grafts or alloplast grafts performed simultaneously with implant placement,
  6. Large-volume combination defects require staged reconstruction.

The author asserts that the use of prosthetic-guided soft tissue healing to enhance aesthetic outcomes in implant therapy by early introduction of prosthetic components that correspond to the cross-sectional anatomy of the lost tooth or the planned aesthetic replacement at the gingival level by the use of custom abutments and provisional restorations or custom tooth-form healing abutments.

Conclusion: successful management of a lost single tooth in an area of high aesthetic importance requires systematic functional and aesthetic evaluation to identify factors that could enhance the final aesthetic outcome and plan inter-disciplinary intervention.

Lasella 2003:


Lasella J, et al

Title: Ridge preservation with Freeze-Dried bone allograft and collagen membrane compared to extraction alone for implant site development: A clinical and histologic study in humans.

Source: J Periodontol 2003 July; 74(7)(3): 990-9.

Purpose:

Tooth extraction leads to loss of ridge width and height. The aim of this 6-month randomized, controlled, blinded clinical study was to compare the post extraction dimensional changes following extraction alone or extraction plus ridge preservation with an intrasocket mineralized freeze-dried bone membrane (FDBM), and to determine whether there were significant differences between these two procedures. Furthermore, to determine the effect of collagen membrane on soft tissue thickness overlaying alveolar bone, as to compared to soft tissue thickness following extraction alone.

M&M:

Twenty four patients, 10 males, 14 females, ages 28 to 76, required non-molar extraction and delayed implant placement. They were selected randomly to receive either an extraction alone (EXT) or ridge preservation (RP) using tetracycline hydrated freeze-dried bone allograft (FDBA) and a collagen membrane.

Following extraction, horizontal and vertical ridge dimensions were determined using a modified digital caliper and an acrylic stent. In the RP group, FDBA was hydrated in tetracycline and placed into socket. A collagen membrane was hydrated in sterile saline for 5 minutes, trimmed and placed to cover the socket. Flaps were replaced without obtaining complete socket cover, and sutured with 4-0 silk.

All subjects were seen weekly until soft tissue closure, and then monthly until implant placement. During surgical reentry for implant placement a trephine was used to remove a core from the site, which was placed into 10% buffered formalin. These cores were prepared for histological analysis to obtain percent of cellular bone, acellular bone and trabecular spaces. An osteotomy site was prepared and each patient received a 1 or 2 stage end osseous root-form dental implant. Flaps replaced and sutured.

Results:

Width of the RP group decreased from 9.2 ± 1.2 mm to 8.0 ± 1.4 mm, while the width of the EXT group decreased from 9.1 ± 1mm to 6.4 ± 2.2 mm. This is a difference of 1.6 mm.

Both groups lost ridge width, but an improved result was found in the RP group. Most of the resorption occurred from the buccal; maxillary sites lost more width than mandibular sites.

(EXT group)

The vertical change for RP group was a gain of 1.3 ± 2.0 mm vs. a loss of 0.9 ± 1.6 mm for the EXT group. This represents a height difference of 2.2 mm.

Histologic analysis reveals more bone in RP group: 65% ± 10% vs. 54 ± 12% in EXT.

The RP group included both vital bone (28%) and non vital (37%) FDBA fragments.

Conclusion:

Ridge preservation using FDBA and a collagen membrane improved ridge height and width dimensions when compared to extraction alone. These dimensions may be very suitable for implant placement, especially in areas where loss of ridge height would compromise esthetic result. The quantity of bone observed histologically, was greater in preservation sites, although these sites included vital and non-vital bone. The most predictable maintenance of ridge width, height and position was achieved when a ridge preservation procedure was employed.

Wood 2011:


BACKGROUND:

Allografts, such as demineralized freeze-dried bone allograft (DFDBA) and mineralized freeze-dried bone allograft (FDBA) are commonly used by clinicians for ridge preservation procedures. The primary objective of this study is to histologically evaluate and compare the healing of non-molar extraction sockets grafted with DFDBA versus FDBA for ridge preservation. The secondary aim of this study is to compare dimensional changes in ridge height and width after grafting with these two materials.

MATERIALS:

Forty patients were randomly divided into two groups of 20. Extraction sockets were filled with either FDBA or DFDBA. To minimize variables associated with the organ donor and with tissue processing, all of the graft material was procured from a single donor; the only difference in the two materials was the percentage mineralization of the final bone graft. A 2-mm-diameter core biopsy was taken from each grafted site ≈19 weeks after grafting. Histomorphometric analysis was performed to determine percentage of vital bone, residual graft particles, and connective tissue (CT)/other non-bone components.

RESULTS:

There were no significant differences when comparing changes in alveolar ridge dimensions of the two groups. There was no significant difference in percentage CT/other between groups. DFDBA had a significantly greater percentage of vital bone at 38.42% versus FDBA at 24.63%. The DFDBA group also had a significantly lower mean percentage of residual graft particles at 8.88% compared to FDBA at 25.42%.

CONCLUSION:

This study provides the first histologic and clinical evidence directly comparing ridge preservation with DFDBA versus FDBA in humans and demonstrates significantly greater new bone formation with DFDBA

Topic:rhBMP-2
Authors: Fiorellini J

Title:Randomized study evaluatingrecombinant human bone morphogenetic protein-2 for extraction socket augmentation.

Source: J Periodontal. April 2005, Volume 76, Number 4- 605-13

Type: Clinical

P: to evaluate the efficacy of bone induction for the placement of dental implants by two concentrations of recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered on a bioabsorbable collagen sponge (ACS) compared to placebo (ACS alone) and no treatment in a human buccal wall defect model following tooth extraction.

Methods: 80 patients (43 males and 37 female) mean age of 47.4, requiring local alveolar ridge augmentation for buccal wall defects (50% buccal bone loss of the extraction socket) of the maxillary teeth (bicuspids forward) immediately following tooth extraction were enrolled. Two sequential cohorts of 40 patients each were randomized in a double-masked manner to receive 0.75 mg/ml or 1.50 mg/ml rhBMP-2/ACS, placebo (ACS alone), or no treatment in a 2:1:1 ratio. Efficacy was assessed by evaluating the amount of bone induction, the adequacy of the alveolar bone volume to support an endosseous dental implant, and the need for a secondary augmentation.

Results: Assessment of the alveolar bone indicated that patients treated with 1.50 mg/ml rhBMP-2/ACS had significantly greater bone augmentation compared to controls (P 0.05). The adequacy of bone for the placement of a dental implant was approximately twice as great in the rhBMP-2/ACS groups compared to no treatment or placebo. In addition, bone density and histology revealed no differences between newly induced and native bone.

Conclusion: the stimulation of host healing
responses with rhBMP-2 versus dependence on the osteoconductive properties of a carrier material enhanced predictability and provided a substantial patient clinical benefit.

BL: Buccal wall extraction defect model utilized to assess acombination of rhBMP-2 and a commonly utilized collagen sponge had a striking effect on de novo osseous formation for the placement of dental implants.

Topic: Extraction
Authors:Farina R , et al

Title: Plasma rich in growth factors in human extraction sockets: a radiographic and histomorphometric study on early bone deposition.

Source: J Clin Periodontol. 2005 Feb;32(2):212-8.

Type: Clinical study

Keywords: CD68 antigen; alveolar process; bone remodeling; growth factors; histology; osteocalcin; plasma; platelet-rich plasma; tooth extraction; von Willebrand factor

Purpose: To determine whether and to what extent the additional application of plasma rich in growth factors (PRGF) to an extraction socket may influence the early bone deposition.

Methods: Twenty-eight patients (age range: 34–74 years) contributing 36 extraction sockets were included in the study. Sockets were either treated with PRGF (PRGF group; 18 sites in 11 patients) or left to spontaneous healing (control group; 18 sites in 17 patients). Radiographic and histomorphometric analysis was performed on bone cores trephined from each healing socket after 4–6 (T1) or 7–10 (T2) weeks of healing.

Results: Patients treated with PRGF application showed: 1- similar bone volume and tissue mineral content, 2- a trend, although not statistically significant, toward a greater number of CD68+ cells (at T1 and T2) and vVW+ cells (at T1), and 3- a similar OCN staining score throughout the study, when compared with control group.

Conclusions: Plasma rich in growth factors-treated group did not show any enhancement in early (4 and 8 weeks) bone deposition compared with control group.

Topic:Ridge preservation
Authors:Coomes AM, Mealey BL

Title:Buccal Bone Formation After Flapless Extraction: A Randomized Controlled Clinical Trial Comparing Recombinant Human Bone Morphogenetic Protein-2/Absorbable Collagen Carrier and Collagen Sponge Alone.
Source: J Periodontol. 2013 Jul 4.

Type:Review

P:To determine the effects of flapless extraction technique in combination with rhBMP-2 on a resorbable collagen sponge in extraction sites with greater than 50% buccal dehiscence

M&M:39 patients requiring extraction op hopeless teeth with greater than 50% buccal dehiscence. Flapless extraction was performed and patients were selected at random to have a collagen sponge or a collagen sponge soaked in rhBMP-2 into the extraction site. CBCTs were obtained at baseline after extraction and again at 5 months postoperatively.

R: rhBMP-2 on a collagen sponge was able to regeneration portions of lost buccal plate, maintain ridge dimension, and allow for implant placement 5 months post extraction. The rhBMP-2 group was significantly better in clinical regeneration, clinical ridge width at 5 months, and radiographic ridge width at 3 mm from the alveolar crest (with molar exclusion). There was significantly less remaining buccal dehiscence clinically and radiographically at 5 months when compared to control. Significantly more implants were placed in the rhBMP-2 group that did not need additional augmentation.

BL:rhBMP-2 with a collagen sponge performed better than collagen sponge alone when used in flapless extraction sites with a buccal dehiscence. Results showed it was superior in regeneration of buccal plate, maintenance of ridge dimension, and allowance for implant placement 5 months later.

Topic: Membrane

Authors: Carbonell JM, Martín IS, Santos A, Pujol A, Sanz-Moliner JD, Nart J.

Title: High-density polytetrafluoroethylene membranes in guided bone and tissue regeneration procedures: a literature review.

Source: Int J Oral Maxillofac Surg. 2014 Jan;43(1):75-84

Type: Review

Keywords: dense PTFE; high-density PTFE; microporous PTFE; nano-porous PTFE; non-expanded PTFE; non-permeable PTFE; non-porous PTFE

Purpose: The aim of this literature review was to analyze and describe the available literature on n-PFTE, report the indications for use, advantages, disadvantages, surgical protocols, and complications.

Method: The medical databases Medline-PubMed and Cochrane Library were searched and supplemented with a hand search for reports published between 1980 and May 2012 on n-PTFE membranes. The search strategy was limited to animal, human, and in vitro studies in dental journals published in English.

Results: Twenty-four articles that analyzed the use of n-PTFE as a barrier membrane for guided tissue regeneration and guided bone regeneration around teeth and implants were identified: two in vitro studies, seven experimental studies, and 15 clinical studies.

Conclusion: There is limited clinical and histological evidence for the use of n-PTFE membranes at present, with some indications in guided tissue regeneration and guided bone regeneration in immediate implants and fresh extraction sockets.

Authors: Nevins M, Mellonig J et al

Title:Implants in regenerated bone: long-term survival

Source:Int J Periodontics Restorative Dent. 1998 Feb;18(1):34-45.

Type:Restrospective study

Keywords:none

Purpose:Evaluate the long-term success of implants in function in bone regerated by GBR combined with an autograft or allograft

Methods and Materials: Both autogenous and allografts (FDBA) were used in combination with a barrier membrane (e-PTFE) to reconstruct bone using either a simultaneous or staged approach. Different implant systems were used. Subjects were followed from 6 to more than 74 months post loading (single and multiple unit prosthetics). Periapical radiographs taken to evaluate implant health and bone quality at follow up evals. Patients were seen at 6 months, 1 year, and annually after placement.

Results: Eight of the implants were lost, for a success rate of 97.5% (all implants placed in maxilla, occlusal loading presumed etiology of failure). Mean cumulative bone loss as determined over 74 months of loading was 0.64mm. Least amount of bone loss was seen in those sites without any complication from infection.

Conclusion: Regenerated bone reacted to implant placement in a manner that was clinically similar to native bone. The type of graft material did not affect the clinical success of the implants, nor did the use of submerged versus non-submerged implants nor a staged versus a simultaneous approach. This correlates with other studies that report 98.6% success in grafted sites.

Topic: Ridge augmentation

Authors: Barone Antonio et al

Title:A Randomized Clinical Trial to Evaluate and Compare Implants Placed in Augmented Versus Non-Augmented Extraction Sockets: 3-Year Results

Source:Journal of periodontology, 83(7), 836-846. doi: 10.1902/jop.2011.110205

Type:Controlled clinical trial

Keywords:Alveolar bone loss, bone substitutes, dental implants, survival rate

Background:The alveolar ridge undergoes reabsorption and atrophy subsequent to tooth removal and thus exhibits a wide range of dimensional changes. Preservation of the alveolar crest after tooth extraction is essential to enhance the surgical site before implant fixture placement.

Aim:To investigate and compare the need for additional augmentation procedures at implant insertion, as well as the success rate and marginal bone loss for implants placed in the grafted sites versus those placed in naturally healed sites.

Methods:Forty patients with >1 hopeless tooth were randomly allocated to: 1) a test group, receiving extraction and grafting corticocancellous porcine bone; and 2) a control group, receiving extraction without any graft. After 7months of healing, implants were inserted in each of the sites. The implants were submerged and loaded after 4 months with metal–ceramic rehabilitation. The follow-up included evaluation of implant diameter and length, the need for additional augmentation procedures at implant placement, implant failure, and marginal bone level changes. All patients were followed over a 3-year period.

Results:One implant failed in the control group at the second stage of surgery (6 months after placement); one implant failed in the test group after 2 years of loading. The cumulative implant success rate at the 3-year follow-up visit reached 95% for both groups. No statistically significant differences were detected for marginal bone changes between the two groups.

Conclusion:The results of the present study show that there were no differences in the survival rates between implants placed into augmented and non-augmented sites. However, grafted sites allowed placement of larger implants and required less augmentation procedures at implant placement when compared to naturally healed sites.

 

Implant Success in Grafted Sites

Topic: Implant Success in Grafted Sites

Author: Marconcini, S., Giammarinaro, E., Derchi, G., Alfonsi, F., Covani, U., Barone, A.

Title: Clinical outcomes of implants placed in ridge-preserved versus nonpreserved sites: A 4-year randomized clinical trial

Source: Clin Implant Dent Relat Res. 2018;20:906–914.

DOI: 10.1111/cid.12682

Type: Randomized clinical trial

Keywords: dental implants, ridge preservation, tooth extraction

Purpose: to assess success and survival rates of implants placed in extraction sockets, with spontaneous healing, or grafted with cortical porcine bone, or collagenated corticocancellous porcine bone

Methods:42 healthy patients in need of single tooth extraction and implant supported restoration participated. Tooth extraction was the least traumatic possible and performed without raising a full thickness flap. The groups were:

  • 13 extraction sockets with spontaneous healing––ctrl;
  • 15 extraction sockets grafted with collagenated cortico-cancellous porcine bone, with a particle size between 600 and 1000 lm––coll;
  • 14 extraction sockets grafted with cortical porcine bone, with a particle size between 600 and 1000 lm–– cort.

In the test groups, the sockets were grafted reaching the buccal and palatal alveolar bone walls and a collagen membrane was pushed under the interdental papillae with the aid of surgical periotomes without covering the bone walls. The membrane was stabilized with stitches and remained exposed to the oral cavity. In the control group, the sutures were used to stabilize the blood clot. No releasing incisions or muco-periosteal flaps were performed in any of the groups. 3 months after healing the implants were placed. After 4-months, implant impressions were made. A customized final abutment was prepared and connected to the implant, and the definitive metal-ceramic restoration was cemented. Peri-implant marginal bone levels were evaluated on intraoral radiographs, at the mesial and distal sites. The reference point was the fixture-abutment interface. Intraoral photographs were taken at baseline and follow-up visits to evaluate soft tissues. A digital camera was used, at a fixed angle and magnification setting. A periodontal probe was used to perform direct measurements on the peri-implant mucosa. The assessment of the Pink Esthetic Score (PES) was performed on digital photographs. Patients were clinically evaluated every 6 months after loading and any complication was recorded. Implant failure was defined by the presence of implant mobility or by the presence of persistent or chronic infection. Successful implants were those within a cut-off of registered mean radiological periimplant bone resorption, not greater than 1.5 mm during the first year of loading and 0.2 mm the years after.

Results: The mean marginal bone change at 3 and 4 years was significantly greater than that at 1 and 2 years. There were no significant differences between the 2 grafting materials but MBL was significantly greater in the nongrafted sites. Changes in MBL were significantly dependent on time. The main bone remodeling occurred in the control group (ctrl) when compared to grafted sites. Furthermore, additional augmentation procedure was required for 13.7% of the implants placed in grafted sites versus 41.6% of the implants placed in nongrafted sites. Also, the cort group had a significant higher PES score than both coll and ctrl group at a 4-year evaluation.The overall PES did not significantly change between the third and fourth year after restoration. Therefore, 3 years after treatment, the esthetic outcome was stable for the entire cohort. Furthermore, the width of keratinized gingiva (WKG) was significantly influenced by the grafting procedure 4 years after restoration .

The survival rate was 100% for each group 4 years after loading. Regarding success rates, no implants incurred radiographic bone loss greater than 1.5 mm neither during the first year of function nor in the following follow-ups. Thus, the success rate at a 4-year evaluation was 100%.

Discussion: .Ridge preservation is particularly valuable in order to achieve enhanced restorative and esthetic outcomes. Root convexity was the item that influenced the overall PES the most. Possibly the cortical porcine bone, showing a lower resorption rate over a given amount of time, contributed to a more pronounced vestibular bulge in correspondence of the missing root.

Conclusion:The 4-year evaluation suggested that the ridge preservation led to better implant clinical outcomes. The cortical-porcine bone showed better esthetic results.


Topic: implant survival

Authors: Tran DT, Gay IC, Diaz-Rodriguez J, Parthasarathy K, Weltman R, Friedman L

Title: Survival of dental implants placed in grafted and nongrafted bone: a retrospective study in a university setting

Source: Int J Oral Maxillofac Implants 2016; 31(2): 310-317

Keywords: dental implant, healing, survival rate, bone grafting

Purpose: To compare the survival rates of implants placed in native one as compared with grafted sites and identify any risk factors associated with failure.

Methods: A retrospective chart review was conducted of all patients receiving dental implants at UT-Houston. Patients were excluded with genetic disease affecting bone metabolism and radiation/chemotherapy. Additionally, implants were excluded if grafting was only done at time of placement, narrow implants (<3mm), short implants (<5mm) or implants placed at previously failed sites.

Control implants included those placed in native bone, test implants were those placed at sites that were augmented prior to implant placement.

Results: A total of 1222 patients with 2729 implants were included who had implants placed between 1985 and 2012. About 2/3 of the implants were placed in native bone and 1/3 were placed in grafted sites. Follow-up ranged from 0.2months to 16.8 years, with a median of 20months. During follow-up, 6% of the implants were lost with 9% of patients experiencing implant failure.

Cumulative Survival Rates and Risk Factors: CSR was 92% at 5 years and 87% at 10 years for implants in native bone, and 90% at 5 years and 79% at 10 years for implants in grafted bone. While there is a difference it was not statistically significant. Implant failure was significantly associated with tobacco use and professional maintenance but not with augmentation or other variables evaluated.

Discussion: There were no differences in dental implant survival rate when placed in native bone or bone-grafted sites. The significant risk factors for implant failure were tobacco use and lack of professional maintenance.

 

Socket Shield

Topic: Extraction

Author: Gharpure AS, Bhatavadekar NB

Title: Current evidence on the socket-shield technique: a systematic review

Source: J Oral Implantol. 2017 Oct;43(5):395-403.

DOI: 10.1563/aaid-joi-D-17-00118

Type: Review

Purpose: to assess the literature available on the socket-shield technique and weigh its biological plausibility and long-term clinical prognosis.

Methods:

  • The focused Pico questions was ‘‘What is the long-term clinical prognosis and the biologic plausibility of the socket-shield technique used for preservation of buccal/proximal/crestal bone for implant treatment in humans on the basis of clinical, histologic, and radiologic evaluation?’’
  • A systematic search was performed in PubMed-Medline, Embase, Web of Knowledge, Google Scholar, and the Cochrane Central Register of Controlled Trials from January 1970 to April 2017.
  • Complications and adverse effects were defined as histologic, clinical, or radiologic detrimental effects that would diminish the long-term success of the implant treatment. For animal studies, clinical outcomes assessed were implant/shield exposure, presence of inflammation, mucositis, or peri-implantitis. Histologic outcomes assessed were failure of osseointegration or formation of periodontal ligament (PDL) or cementum on the implant surface.

Results:

  • A total of 23 studies were included in this systematic review. One was a case-control study, 4 had animal histologic reports, with 2 of them6,16 accompanied by a human case report. One study was an abstract documenting 23 cases. The remaining 17 articles were clinical human case reports and case series.
  • Parlar et al were the first ones to place 18 implants in the center of a prepared hollow chambers of decoronated roots with slits in the periphery of 9 mongrel dogs.
    • Four months later, histo revealed newly formed PDL, alveolar bone, and root cementum in the space between the implant and the wall of the dentin chamber. A fibrous capsule covered their surfaces, and they failed to osseointegrate.
  • Hurlezer intentionally left a buccal portion of the remnant root coated with Emdogain to preserve the buccal cortical plate from resorption during an immediate implant placement and were the first ones to name the technique socket shield.
    • Histo on 4 implants showed cementum formation on implant surface where direct root-implant contact was noted. When the implant and the root piece were in close proximity with no surface contact, a 0.5 mm connective tissue band was found between the implant and the buccal root piece. They also presented a clinical case report using this technique wherein the implant was immediately loaded and followed up for 6 months

Conclusion: After going through available literature, overall evidence in support of the socket-shield technique seems limited at the present. Histologic evidence indicates rapid bone loss, failure of osseointegration, formation of cementum, and PDL or PDL-like fibrous tissue on implant surfaces in proximity to the shield, weakening the biologic plausibility of this technique.

 

Topic: late failure

Authors: Nevins ML, Langer L, Schupbach.

Title: Late dental implant failures associated with retained root fragments: case reports with histologic and SEM analysis.

Source: Int J Perio Rest Dent. 2018;38(1)

DOI: 10.11607/prd.3463.

Type: case report

Keywords: dental implant, retained root fragment, histology, periimplantitis

Purpose: To presents two cases of long-term failure post loading associated with unintentionally retained root fragments.

Methods: Radiographic, scanning electron micrographic (SEM), and histologic findings of two cases of late dental implant failures associated with retained root fragments, are reported. It remained stable for more than 8 years, but at 8 years, the bone immediately surrounding the implant appears denser than that adjacent to the natural tooth. The observed increase in opacity adjacent to the implants is not in itself indicative of any pathology as bone density increases due to osseous condensation. 2 years after, patient presents with an emergency with discomfort with the implant, now probing 8-9 mm with suppuration. Opacity on the mesial surface of the implant is consistent with a retained root fragment. Implant was removed and socket was grafted. SEM evaluation showed extensive bacterial infiltration, calculus formation and presence of thick biofilm on the implant. LM confirmed presence of tooth material.

Case 1: A 47-year-old woman, presented for maintenance. Molar had had RCT and epicoectomy but subsequently fractured and extracted. The site was grafted with bovine bone graft and allowed to heal for 5 months. A submerged implant was placed. It remained stable for more than 8 years, but at 8 years, the bone immediately surrounding the implant appears denser than that adjacent to the natural tooth. The observed increase in opacity adjacent to the implants is not in itself indicative of any pathology as bone density increases due to osseous condensation. 2 years after, patient presents with an emergency with discomfort with the implant, now probing 8-9 mm with suppuration. Opacity on the mesial surface of the implant is consistent with a retained root fragment. Implant was removed and socket was grafted. SEM evaluation showed extensive bacterial infiltration, calculus formation and presence of thick biofilm on the implant. LM confirmed presence of tooth material.

Case 2: A 56-year-old woman was referred for class III mobility of an implant. No pain or suppuration. Tooth in that site had had RCT and subsequently fractured. Tooth was extracted but part of the root had remained in the socket due to ankylosis. Immediate implant was placed. The implant remained in function for 4 years. Implant was removed and site was grafted. SEM showed bacterial infiltration like first case. LM confirmed presence of tooth material.

Conclusion: Unintentionally retained root fragments in proximity to dental implants may also contribute to late implant failures. These failures can occur up to 10 years post loading. Long-term follow-up and careful inspection of failed implants may help in quantifying the frequency of this problem and formulating techniques that will avoid these adverse effects in the future.

 

Early and Immediate Placement

Topic: Early/ Immediate placement

Authors: Buser D, et al.

Title: Implant placement post extraction in esthetic single tooth sites: when immediate, when early, when late?

Source: Periodontol 2000. 2017 Feb;73(1):84-102.

DOI: 10.1111/prd.12170

Type: Discussion

Keywords: implant placement; immediate, early; late placement; esthetics

Purpose: to present the history of implant placement post-extraction and the evolvement of today’s clinical approaches.

Discussion:

Pioneer phase (1975-1989) Dominance of implant placement in healed sites. First to evaluate immediate DI placement Professor Wilfred Schulte (Germany) Tubinger Immediate Implant in 1978, which was ceramic. Lost momentum when manufacture switched to titanium and only published in small journals in Germany.

Trial and Error phase (1990-2003) GBR surgical techniques in conjunction with immediate placement. E-PTFE membranes predominately used with autogenous and allograft bone. Use of resorbable membranes shifted from e-PTFE to eliminate exposures and 2nd surgery for membrane removal.

First reviews were only 12 month observation times and data was inconclusive for long-term survival of immediate and delayed placement. 12 month showed predictable treatment for immediate and delayed placements. Classified timing terminology, Hammerle et al. proposed 4 categories Type I-IV then amended by Chen and Buser to be immediate, early, and late implant placement.

By 2008, more clinical studies done to be included in new reviews that showed GBR is beneficial especially in immediate and early placement stages with survival rates above 95%. These studies also evaluated esthetic scores and found recession of facial mucosal margin was common with immediate placement with a risk of 20-30% for recession over 1 mm. Further studies concluded increased risk of recession when facial plate is missing post-extraction and with pts having a thin wall phenotype (<1mm).

ITI Consensus Conference came up with clear recommendations for different treatment options.

  • Immediate (type I): experienced clinicians and ideal anatomy of fully intact buccal plate with thick phenotype (>1mm), thick gingival biotype, no infection, and sufficient apical/ palatal bone for DI insertion. Rare cases when facial plate is thick enough, Braut et al. found only 4.6% of maxillary anteriors had >1mm thickness. Immediate placement should also be performed flapless to reduce facial recession. This approach has been fine tuned to incorporate soft tissue augmentation as well as “socket seal” technique using a prefabricated acrylic shell and immediate restoration out of occlusion. Still, results are only short term.
  • Early 4-8 wks(type II): when not all of the type I criteria met

Advantages include soft tissue healing to increase KG.

Steps include flapless extraction, healing 4-8 weeks with flap raised for DI placement. Placement is 1.5mm palatal to future point of emergence and 3-4mm space from shoulder to future DI mucosal margin. Autogenous + deproteinized bovine bone mineral particles are placed in defect areas then covered with non-crosslinked collagen membrane (Bio-Gide). At 8 weeks the implant is uncovered and prosthetic is placed. Results show low risk of mucosal recession and good to excellent esthetic outcomes with 2mm of facial bone thickness after 6-9 years follow-up.

  • Early 12-16 wks (type III): when won’t get primary stability at 4-8 wks allow time for some bone healing. Also in cases of PA lesion that won’t allow earlier placement. This type of placement is common for multi-rooted teeth.
  • Late placement >6 months (type IV): insufficient bone volume at time of extraction for implant stability requiring extended healing time. Socket grafting is performed most commonly to preserve the ridge.

Conclusion: Four different treatment options are available for post-extraction implant placement. There are well defined selection criteria for each of these treatments. Late implant placement is the least attractive option for the patient and only used when absolute necessary.


Topic: Implant bone level

Authors: Schropp L, Wenzel A.

Title: Timing of single implant placement and long-term observation of marginal bone levels

Source: Eur J Oral Implantol. 2016;9 Suppl 1:S107-22

DOI: – PMID: 27314115

Type: Review

Keywords: dental implant, long-term, marginal bone level, outcome, review, timing

Purpose: to assess the outcome of immediate or early placement of implants after tooth extraction, supporting a single- tooth restoration, with focus on the long-term marginal bone level

Methods:

  • RCT and clinical control trials included in electronic search with a follow-up period of at least 12 months
    • The following information was extracted:
      • follow-up period, implant placement protocol, number of patients and implants, implant survival rate, BL, implant site, loading protocol, implant system and tissue augmentation.

Results:

  • 115 articles were included
    • 6 studies were RCTs
      • Schropp: compared from crown delivery to 10-year follow-up
        • no changes in mean BL for the early group, a minor bone loss of 0.2 mm for the delayed group, and a minor bone gain of 0.2 mm for the late group were found.
        • NSSD in mean BL values at 10 years were seen among the groups.
      • Palattella: compared immediate implants with implants placed 8 weeks after tooth extraction (early)
      • Block: compared immediate implants with implants placed 16 weeks after extrac- tion (delayed)
      • Lindeboom: compared implants placed in periapically infected extraction sockets (immediate) with implants placed 12 weeks after extraction.
        • For the Palattella, Block, Lindeboom RCTs, a mean marginal bone loss of 0.5 mm interproximally was found, or the BL was situated less than 0.5 mm apically to the implant shoulder, during the most recent control visit, irrespective of timing protocol; NSSD existed between test and control groups
      • The trend for CCT was same as RCT
        • Cooper demonstrated marginal bone gain at immediate implants and bone loss at implants placed in healed bone, NSSD at 1 year mark
        • Vandeweghe and Carini found a SSD in bone loss between immediate and delayed implants in favor of immediate
        • Overall, it was found that the mean marginal bone loss from baseline to the latest follow-up visit was less than 1.5 mm
      • Survival rates were high for implants irrespective of whether they were placed according to the immediate/early or conventional protocol
        • Most studies demonstrated survival rates higher than 90% for immediate implants and approximately 80% if studies showed a survival rate of 95% or higher.

Conclusion:

  • Implants after tooth extraction may be a viable treatment with long-term survival rates and marginal bone level conditions, matching those for implants placed conventionally in healed bone


Topic: Early and Immediate Placement

Author: Chen S, Buser D.

Title: Esthetic Outcomes Following Immediate and Early Implant Placement in the Anterior Maxilla—A Systematic Review.

Source: Int J Oral Maxillofac Implants. 2014 Jan-Feb;29(supplement):186-215

DOI: 10.11607/jomi.2014suppl.g3.3

Type: Systematic Review

Keywords: bone grafts, CBCT, contour augmentation, early implant placement, esthetics, GBR, immediate implant.

Purpose: 1) Quantitatively estimate the esthetic outcomes of implants placed in post-extraction sites. 2) evaluate the influence of simultaneous bone augmentation procedure

Methods:

  • Data including time of implant placement post-extraction, simultaneous placement of bone grafts, connection of provisionals after placement, peri-implant soft tissue dimensional changes, and esthetic indices.

Results:

  • 50 studies were included in the study using 5 RCTs, 5 cohort studies, 3 cross-sectional studies, and 25 case series.
  • Study outcomes ranged anywhere from 6 months – 5 years.
  • Randomized Studies:
    • Comparing immediate vs early placement in the maxillary anterior followed by 48hr restoration was reviewed and found significant recession in both groups with NSSD up to 2 years.
    • Comparing Type 1 and 3 implant placement at single-tooth sites with evidence of periapical lesions showed no difference in level of midfacial mucosa between the two groups but a slightly greater recession in Type 1 than Type 3. (0-2mm)
    • Comparing Immedaite versus delayed restoration of immediately placed implants combining grafting with DBBM showing significantly less midfacial recession in the immediate restoration group compared to the delayed group. NSSD found for recession of M or D papillae between the two groups.
  • Non-Randomized Studies:
    • Combined Cohort Study
      • Adequate sockets treated with a flapless Type 1 implant placement
      • Compromised sockets treated with:
        • Flapless type 1 implant placement with non-submerged approach
        • Type 2 placement 6 weeks after extractions with simultaneous hard/soft tissue augmentation
        • Type 1 implant placement with simultaneous soft/hard tissue augmentation
      • Deficient sockets were reconstructed with GBR and soft tissue grafting
      • After 12 months:
        • All adequate sockets had satisfactory esthetic outcomes,
        • Compromised sockets treated with type 1 implant placement initially had adequate esthetics but 50% downgraded to compromised after 1year
        • Compromised sockets with type 2 showed 87.5% satisfactory at time of restoration and 62.5% in the same classification at 1 year.
      • Miyasoto Cohort
        • Showed significantly greater recession at 2 year follow-up with type 1 placement compared to type 2 placement
        • Type 1 was combined with autogenous bone graft
        • Type 2 combined with GBR using non-resorbable membranes
        • Type 2 combined with GBR with resorbable membranes
        • Recession results: 0.85, 0.06, 0.50mm respectively.
        • SSD between Type 1 and Type 2 w/non-resorbable membrane
        • Vertical resorption of facial bone results: 3.25, 0.13, 0.70mm respectively
      • Gotfredsen Cohort:
        • Type 2- single tooth implants placed 4 weeks after extraction
        • Type 3- single tooth implants placed 12 weeks after extraction
        • After 5 years:
          • Difference in crown length between implants and control teeth was 0.6mm in Type 2 and 0.7mm in Type 3
          • Papillae recession was NSSD
        • Type 1 Vs Type 4
          • Comparing Type 1 and Type 4 single tooth implant placement with immediately loading showed early failure in 3.6% in type 1 and 1.7% in type 4.
          • NSSD slight positive change in mucosal levels from placement to 3 years 0.23 and 0.27mm respectively
          • NSSD slight gain in papillae height from placement to 3 years 0.29 and 0.53mm respectively.
        • Type 1 vs Ridge preservation with DFDBA
          • Implants immediately restored and reviewed after 2 years
          • Lengths of crowns were significantly longer in ridge preservation group compared to Type 1 placement (8.6 vs 7.4mm)
        • EMD compared to resorbable collagen membrane combined with Type 1 placement
          • Significantly less recession in EMD compared to membrane sites
        • Case Series
          • Predominant finding was recession of midfacial mucosa and papillae occurred with post-extraction implant placement
        • Non-randomized studies

Discussion:

  • This study was conducted to identify changes in the position of peri-implant mucosa, and changes in esthetic indices using only single teeth adjacent to natural dentition.
  • The evidence had significant heterogeneity due to differences in the studies included.
  • Considering positional changes of the midfacial peri-implant mucosa, there was NSSD between immediate (type 1) and early implant placement (type 2).
    • Type 1 placement studies revealed more homogenous results when a flapless immediate placement was followed with a bone and CT graft combined.
  • For changes in position of papillae there was no obvious trend in outcomes when comparing flapless vs flapped approach and an immediate provisional.
  • The evidence to evaluate esthetic outcomes in post-extraction implants are based on a limited number of studies overall.
  • Current evidence suggests that acceptable outcomes can be achieved with immediate (type 1) and early placement (type 2 and 3).
    • Anticipating 0.5mm of midfacial recession after implant placement
    • More variation was seen in Type 1 with recession seen >1mm than in type 2 and 3 placements.
    • Risk for recession in Type 1 placement is 20-30%.
  • Risk factors for recession: pre-existing defects of facial bone, thin facial bone, thin soft tissue biotype, facial positioning of implant.
  • Ways to reduce risk of recession:
    • Strict case selection, intact facial bone, medium tissue biotype
  • Ways to reduce risk of recession in Type 1:
    • Concomitant CT grafts, low-substitution bone fillers, flapless surgery
  • Evidence shows that recession of single tooth papillae of 0.5-1mm was anticipated following implant placement regardless of timing of placement.
    • Little evidence to support flapless surgery or immediate provisional crown to reduce papilla loss
  • PES scores were in a narrow range of 9.5-11.5, but this is hard to consider strictly due to the number of factors that are taken into account.

Conclusion:

  • Immediate (Type 1) implant placement is associated with greater variability of outcomes and frequency of recession >1mm in midfacial mucosa compared to early placement.
  • Immediate implants with bone graft, the facial wall was not detectable on CBCT 36-57% of sites and they had more recession compared to sites with detectable facial bone.
  • Early implant placement (Type 2 and 3) combined with BGR demonstrated high frequency of facial bone on CBCT.


Topic: Buccal bone and immediate implants

Author: Gakonyo, et al

Title: Cone Beam Computed Tomography Assessment of the Buccal Bone Thickness in Anterior Maxillary Teeth: Relevance to Immediate Implant placement

Source: Int J Oral Maxillofac Implants. 2018. July/Aug 33(4):880-887

DOI: 10.11607/jomi.6274

Type: Retrospective study

Keywords: bone resorption, dental implants, esthetics, tooth extraction

Purpose: To determine the buccal bone thickness of teeth in the anterior maxillary region of dentate adult Kenyan patients based on previous CBCT scans

Methods:

  • 184 CBCT scans of adult (≥ 18 years of age)
  • Excluded
    • signs of trauma, supernumerary teeth, crowding, marked loss of both buccal and palatal alveolar bones, previous apical surgery, or root resorption in the region of interest and any images that presented with lack of clarity or too much scattering
  • 1,104 teeth met inclusion criteria
  • Galileos comfort plus CBCT unit, exposure of spherical 15cm field of view
    • Voxel size of .3mm
  • Measurement of thickness of buccal bone taken at two points
    • 4mm apical to cementoenamel junction M1 and middle of root M2
    • Used to check reproducibility
    • Measurements repeated 1 month after

Results:

  • Positive correlation between the buccal bone thickness of the teeth on the right side when compared with the same teeth on the left side specifically corresponding to M1 and M2
  • majority (62%) of the tooth sites exhibited a thin buccal bone wall (< 1 mm)
  • only 11% exhibited a thick buccal wall (≥ 1 mm)
    • thin buccal bone found most often at central incisors
    • thick or missing bone found at canines
  • (26%) of the tooth sites, there was a missing buccal bone wall (thickness = 0 mm), especially at M1
  • Male and female
    • Men had thicker buccal bone at M2 of canines (by about .1mm)

Conclusion: buccal alveolar bone walls on the anterior maxillary teeth in this population were generally thin (< 1 mm), with the thickness decreasing with an increase in age. CBCT analysis is informative to clinicians about the presence or absence and quantity of the buccal bone wall for appropriate treatment selection.

 

Topic: Early Implant Placement

Author: Bassir SH, El Kholy K, Chen C-Y, Lee KH, Intini G

Title: Outcome of early dental implant placement versus other dental implant placement protocols: A systematic review and meta-analysis.

Source: J Periodontol. 2018; 1-14

DOI: 10.1002/JPER.18-0338

Type: Systematic review

Keywords: clinical protocols, dental implantation/methods, dental implants, meta-analysis, time factors, tooth extraction, tooth socket/surgery

Purpose: this systematic review and meta-analysis aimed to compare the early implant placement protocol with delayed and immediate implant placement protocols in terms of implant outcomes (risk of implant failure), changes in peri- implant marginal bone level, peri-implant probing depth, and peri-implant soft tissue level.

Methods:

  • Immediate implant placement: placement of implants into fresh extraction sockets immediately after extraction
  • Early implant placement: implant placement following complete soft tissue coverage of the extraction socket (within 3-8 weeks of extraction)
  • Delayed implant placement: placement ≥12 weeks after tooth extraction.

An electronic and manual search of literature was made to identify clinical studies comparing early implant placement with immediate or delayed placement through March 2017 from MEDLINE, Web of Science, EBSCO, and EMBASE database. 12 articles met the inclusion criteria. Data from the included studies were pooled and quantitative analyses were performed for the implant outcomes reported as the number of failed implants (primary outcome variable) and for changes in peri-implant marginal bone level, peri-implant probing depth, and peri-implant soft tissue level (secondary outcome variables).

Results:

  • Of the 12 studies included in this systematic review, one was a randomized clinical trial, five were non-randomized controlled clinical design, and the others were retrospective or cross-sectional design.
  • Significant difference in risk of implant failure was found neither between the early and immediate placement protocols (risk difference = −0.018; 95% confidence interval [CI] = −0.06, 0.025; P = 0.416) nor between early and delayed placement protocols (risk difference = −0.008; 95% CI = –0.044, 0.028; P = 0.670).
  • Significantly lower marginal peri-implant bone loss was found for implants placed using the early placement protocol compared with those placed in fresh extraction sockets (P = 0.001; weighted mean difference = −0.14 mm; 95% CI = −0.22, −0.05).
  • No significant differences were found between the early and immediate placement protocols for peri-implant probing depths and peri-implant soft tissue level, indicating that peri-implant health and soft tissue stability can be achieved using both implant placement protocols.
  • The results of this meta-analysis are similar to those of previous systematic reviews and meta-analyses that indicated the timing of implant placement does not significantly affect the rate of implant failure.

Conclusion:

  • The available evidence supports the clinical efficacy of the early implant placement protocol.
  • Present findings indicate that the early implant placement protocol results in implant outcomes similar to immediate and delayed placement protocols and a superior stability of peri-implant hard tissue compared with immediate implant placement.
  • Well-designed clinical studies are still required to directly compare the effect of timing of implant placement on the peri-implant health, and stability of peri-implant hard and soft tissues.


Topic: Bone graft

Author: Sanz et al.

Title: The effect of placing a bone replacement graft in the gap at immediately placed implants: a randomized clinical trial

Source: Clin Oral Implants Res. 2016 Jun 7.

DOI: 10.1111/clr.12896

Type: randomized clinical trial

Keywords: bone grafts; bone healing; dental implants; immediate implants

Purpose: Evaluate the effect on the dimensional crestal bone changes after filling the gap in the immediate implant sites.

Material and methods:

  • A total of 86 implant, in 86 subjects
  • Excluded;
    • Rampant caries
    • Absence of adjacent natural tooth root
    • Uncontrolled disease
    • Need medication that would compromise osseointegration
    • Smokers
  • Cylindrical dental implants (3.5 or 4.0 in diameter Dentsply)
  • After the implant insertion was assessed the size of the defect, using landmarks
  • Measurements with periodontal probe
  • Thickness of the buccal and palatal bone walls were measured 1 mm apical of the top of the bone crest with a caliper
  • Randomly allocated to;
    • Group A (test). The gap was filled with deproteinized bovine bone mineral with 10% collagen (DBBM-C)
    • Group B (control). No bone replacement graft material was used
  • No implant-supported temporary restorations were used for the first 4 months.
  • At 16 weeks after the implant placement, implant stability was examined and the size of the defect was recorded

Results:

  • Buccolingual dimension of the socket (CC-BP)
    • Buccal and lingual crests not statistically significant
    • Alveolar crest width (buccolingual dimension 1 mm below the crest) not statistically significant
  • Dimension S-OC (horizontal crest dimension)
    • The buccal aspect of the alveolar crest
      • 29% in the test group
      • 38% in the control group.
      • Two groups were statistically significant
    • Dimension of the Gap (Horizontal) SC-B
      • Mean reduction in the gap size at the buccal aspect
      • 6 mm in the test group
      • 2 mm in the control group.
      • Were statistically significant
    • Dimension R-D (vertical defect)
      • Reduced on buccal and palatal aspects.
      • Not statistically significant
    • Dimension R-C (vertical crest reduction)
      • Similar vertical changes at the buccal crest in the test and the control groups
      • Not statistically significant
    • Thin buccal sites (≤1 mm)
      • Sites with a thin buccal bone wall, the reduction in the marginal buccolingual crest dimension was significantly less pronounced in the test than in the control sites.
      • Reductions in the horizontal crest dimension were significantly greater in the test than in the control sites.
      • Horizontal gap fill, was greater in the control than in the test
    • Anterior sites
      • Anterior maxilla was a significantly smaller reduction in the horizontal crest dimension in the test than in the control group
    • Sites with a gap size of ≥ 2 mm
      • The reductions between the test and control sites were not statistically significant

Conclusion:

  • Placing bone replacement graft consisting of DBBM-C significantly reduced the horizontal bone resorptive changes occurring in the buccal bone after the immediate implantation in fresh extraction sockets.

 

Bone remodeling after Implant placement

Topic: Alterations in bone dimension

Author: Lee C, Stoupel J.

Title: Alterations of the bone dimension following immediate implant placement into extraction socket: systematic review and meta-analysis

Source: J Clin Periodontol. 2014 Jun 3.

DOI: 10.1111/ jcpe.12276.

Type: Systematic review

Keywords: bone dimension; immediate implant; meta-analysis; systematic review

Purpose: To analyze horizontal and vertical bone dimensional changes in single tooth site following immediate implant placement.

Methods:

Electronic search in MEDLINE, Cochrane, EMBASE from January 1980 to October 2013.

Inclusion criteria:

-Human subject studies with immediate implant placement after tooth extraction

-Randomized clinical trials, controlled clinical trials, cohort studies or case series

Exclusion criteria:

-Bone dimension measurements less than 3 months or more than 12 months after the procedure

-Studies with no detailed information of measurement method, measurement reference point or timeline.

Results:

A total of 1348 articles were identified after the search process, and finally reduced to six, with 9 groups of datasets for data analysis. All implants in the included studies were rough surfaced with either bone or tissue level implants. The majority of the studies included only maxillary sites but two included mandibular sites as well.

Four studies used flap approach and two used flapless. The measurement methods were either clinically using probe or caliper, or on CBCT.

-In six selected studies, the weighted mean of the Buccal Horizontal Dimensional reduction was 1.07mm and the Buccal Vertical Dimensional reduction was 0.78mm.

-In three studies, the Palatal Horizontal Dimensional reduction was 0.62mm and the Palatal Vertical Dimensional reduction was 0.50mm.

The weighted mean of Buccal Horizonal Dimensional reduction with no graft was 1.32mm and 0.79mm with graft. The weighted mean of the Buccal Vertical Dimensional reduction in the no graft group was 0.86mm and 0.77mm in the graft group.

Discussion/Conclusion:

Numerous studies have demonstrated an association between thin buccal socket wall and greater loss of buccal bone dimension during healing compared to that of a thick buccal socket wall. In this study, thicker buccal socket wall was related to greater reduction in the buccal horizontal bone dimension, and less reduction in the buccal vertical bone dimension, compared with the thinner socket wall.

It has been demonstrated employing principles of bone regeneration, reduces the extent of bone reduction following the extraction compared to socket healing without use of regenerative materials. In the present review, the use of graft or barrier did not show statistically significant correlation with buccal bone dimensional reduction.

The bone dimensions of immediate implant sites demonstrated approximately 0.5–1.0 mm reduction in vertical and horizontal within 1 year follow up. These results could be utilized to forecast the esthetic outcome, possible complications, choice of biological material, and timing of implant placement.

The bone dimensions of immediate implant sites demonstrated approximately 0.5–1.0 mm reduction in vertical and horizontal aspects 4–12 months following surgery. These results could be utilized to forecast the esthetic outcome, possible complications, choice of biological material, and timing of implant placement. However, the results should be interpreted with care because of the data heterogeneity.

 

Topic: Bone remodeling after implant placement

Author: Mazzocco et al.

Title: Bone Volume Changes After immediate implant placement with or without flap elevation

Source: Clinical Oral implants research

DOI: 10.1111/clr.12826

Type: prospective study

Keywords: bone dimensions, bone graft, cone beam computer tomography, immediate implant

Purpose:

1) to evaluate alveolar bone dimensions after immediate implant placement in sockets with an intact buccal plate, grafting the gap between implant and the socket wall with anorganic bovine bone graft.

2) to determine if initial buccal bone width has an influence on bone volume changes

3) to compare the bone volume changes using a flap or a flapless approach after 6 months healing.

 

Methods:

  • Inclusion criteria:
    • Dentate patients having one non-molar tooth planned for extraction
    • Full mouth plaque score and full mouth bleeding score <25%
    • Eventual loss of attachment limited only to areas different from the sites included in the study
    • Primary stability of at least 35N at implant placement.
  • Exclusion criteria:
    • Medical history in which any dental intervention would be contraindicated
    • Any local or systemic disease, conditions or medications that might compromise healing and/or affect the periodontium
    • Smoking habit
    • Inability or unwillingness to return to follow-up visits
    • Presence of a dehiscence or fenestration in the buccal wall after tooth extraction.
  • Tooth extraction was performed in a gentle way to minimize the mechanical trauma onto the surrounding bone.
  • If tooth extraction was not feasible with a flapless approach due to root fracture or a complete destruction of the coronal third of the root, a mucoperiosteal flap was carefully elevated.
  • The Periodontal ligament attached to the bone in the socket walls was left undisturbed. If present, granulation tissue was carefully removed from the socket.
  • Immediately after the extraction a CBCT was taken in order to evaluate the integrity of the facial wall of the socket.
  • Control group:
  • Immediate implant installation.
  • The gap was filled with small granules of anorganic bovine bone graft. No membrane was used. A healing abutment was placed, and the flap sutured around it after being repositioned
  • Test Group:
    • Immediate implant installation with a flapless approach.
    • Gap was filled with small granules of anorganic bone substitute graft and a healing abutment was placed.
    • All implants were placed 3 mm apical to the margin of the prosthetic crown and oriented towards the cingulum of the future implant supported crown of incisors and canines or the center of the occlusal aspect in the case of PMs.
  • At 6 months a second CBCT was performed. At this time a clinical evaluation was made, and standardized periapical radiographs were taken in order to evaluate the peri-implant baseline bone levels.
  • The 3D reconstructions of both CBCTs were superimposed using simplant Pro 2011
  • A series of measurements were performed to determine bone volume changes between the 2 time points.

Results:

Thirty-five patients were included in this study, 20 of which belonged to the test group. Altogether, the differences between baseline and 6 months in buccal plate height, lingual plate height and in ridge width at 2, 4 and 6 mm were 0.48 (+/- 1.35) ; 0.58 (+/- 1.51); 0.64 (+/-0.81); 0.59 (+/-1.36) and 0.52 (+/-1.16), respectively. Only a moderate correlation was observed between initial buccal plate width and buccal plate height at 6 months (P = 0.0001). No statistically significant differences were observed between flap and flapless approach.

Discussion: The results of this prospective study have shown a mean reduction of around 0.5 mm in height and width after placing immediate implants and filling the residual gap with anorganic bovine bone. Secondly, although initial buccal bone width showed no significant correlation with ridge width at 6 months, a moderate positive correlation with buccal bone height at 6 months was seen. Last, no statistically significant differences in outcomes were found in the present investigation between the two treatment protocols although more ridge reduction was observed for the flap group.

 

Placement into infected sites

Topic: Placement into infected sides.

Author: Zuffetti F, Capelli M, Galli F, Del Fabbro M, Testori T.

Title: Post-extraction implant placement into infected versus non-infected sites: A multicenter retrospective clinical study

Source: Clinical Implant Dentistry and Related Research. 2017;19:833–840

DOI: 10.1111/cid.12523

Type: Retrospective clinical study

Keywords: immediate implant placement, infected site, non-infected site, post-extraction site, survival rate

Purpose:

To carry out a multicenter retrospective analysis of records concerning patients subjected to post-extraction immediate implant placement into sites presenting a chronic infection and non-infected sites in order to compare the cumulative survival rates.

Methods:

Clinical records of patients treated with immediate post-extraction implants between January 1998 and September 2014 at 4 private dental clinics and 1 institutional center in northern Italy.

Patients received at least 1 immediate post-extraction implant, which was followed for a minimum of 6 months.

Patients with a systemic disease were excluded as well as patients with periodontal infections or acute endodontic infections

This study was performed according to the principles of the Helsinki Declaration.

The implant-placement site was categorized for the presence of chronic infection (non-infected/infected), if infected, the origin of the infection was assessed (periodontal, endodontic). All the implant information was recorded (implant diameter and length, placement site, torque at insertion, position relative to the buccal alveolar crest (subcrestal, crestal, supracrestal), platform-switching status (Y/N), and the loading protocol).

Implants were also considered to have failed if bone loss greater than half the implant length was observed on radiographs, or if the implant showed mobility.

Results:

369 patients (210 women and 159 men), aged from 22.8 to 81.9 years (average 54.5; median 55.7). 527 total implants, 334 were placed in non-infected sockets and 193 in infected ones.

Of the infected sockets, 134 cases the tooth extracted from a periodontal infection, while 59 from endodontic infection.

A total of 10 implant failures were observed. 7 implants had been placed into non-infected sockets, and 3 into infected ones (2 endodontic infections and 1 periodontal).

Cumulative survival rates were not significant. Non-infected sites: 97.9% while for infected sites 98.4%

Discussion/conclusions:

-Results of this study show that immediate post-extraction implants placed in sites with periodontal or endodontic infections have a cumulative survival rate that did not significantly differ from implants placed into non-infected sites, confirming what has been observed in previous retrospective analyses.

-Origin of the infection has no effect on the implant survival.

 

Topic: Implants in infected sites

Author: Corbella, S., Taschieri, S., Tsesis, I. and Del Fabbro, M.

Title: Post extraction implant in sites with endodontic infection as an alternative to endodontic retreatment: a review of literature.

Source: Journal of Oral Implantology 39, no. 3 (2013): 399-405.

DOI: 10.1563/AAID-JOI-D-11-00229

Type: Literature review

Keywords: Dental implants, endodontic infections, post extraction sites

Purpose: To evaluate the outcomes of implants placed immediately after extraction of teeth with infections of endodontic origin

Methods:

  • Articles were searched along the period from January 1966 to August 2011
  • Only articles on human subjects were considered. At least 12 months of mean follow-up was required for inclusion with no language restrictions.
  • By screening titles and abstracts, a total of 10 articles were found that met the inclusion criteria.
  • Only 9 articles were included as two articles were published from the same cohort group, so the most recent study was included.
  • Data extracted were:
  1. Implant survival, defined as the implant in function without pathologic processes ongoing at the time of the investigation
  2. Reasons for tooth extraction, which were classified as endodontic cause, periodontal cause, root fractures, or combined endodontic-periodontal cause.

Results:

  • A total of 523 implants were inserted in infected sites in 410 patients
  • The follow-up varied from 3 to 117 months from loading.
  • Guided bone regeneration was performed in all studies except one.
  • The surgical protocol always included an accurate debridement of the sockets after teeth extractions and tooth extraction was always described as atraumatic.
  • Antibiotic prophylaxis was administered in 7 studies with different modalities, in one study, antibiotic therapy was generally cited without any specification and in another study, it was not reported. Antibiotic therapy was prescribed in 7 studies after surgical treatment
  • The lesions affecting treated teeth were purely endodontic in 82.3% of cases, purely periodontal lesions in 12.8% of cases, while root fractures and endo-perio lesions were represented (1.4% and 1.0% respectively).
  • The survival rate of the treatment was high in all evaluated studies, ranging from 92% to 100%.
  • No differences were highlighted in implant survival rates using different materials and techniques for guided bone regeneration

Discussion:

  • Immediate implant placement in fresh extraction sites is a viable technique with success rates comparable to those of implants inserted in healed sites. However, the presence of active infection was considered one of the major contraindications of immediate post extraction insertion of implants.
  • The scientific literature on immediate implants in infected sites are poor. Only 10 studies were found and included.
  • Clinical studies reviewed in the present study reported high survival rates, comparable with those reported in studies describing immediate implant insertion in noninfected post extraction sites.
  • Immediate implant insertion in infected sites could be considered a viable alternative to secondary endodontic treatment. However, more well-designed, randomized, controlled trials with a longer follow-up are required to confirm implant insertion in infected extraction sockets as a safe procedure with long-term, high success rates.