Journal Club- March 2020
The papilla access tunnel technique for the treatment of shallow recession and thin tissue in the mandibular anterior region. Allen, E.P. Int J Periodontics Restorative Dent. 2020; 40: 165-169. Doi: 10.11607/prd.4525
Retrospective clinical analysis of risk factors associated with failed short implants. Chen L, Yang T, Yang G, et al. Clin Implant Dent Relat Res. 2020; 22: 112-118. DOI: 10.1111/cid.12879
Soft Tissue Expander for Vertically Atrophied Alveolar Ridges: Prospective, Multicenter, Randomized Controlled Trial. Byun, S.‐H. et al. Clin Oral Impl Res. Accepted Author Manuscript. 2020. DOI: 10.1111/clr.13595
Clinical Outcomes and Bone Level Alterations Around One‐piece Mini Dental Implants Retaining Mandibular Overdentures: 5‐year Follow‐up of a Prospective Cohort Study. Enkling, N., Moazzin, R., Geers, G., Kokoschka, S., Abou‐Ayash, S. and Schimmel, M. Clin Oral Impl Res. Accepted Author Manuscript. 2020. DOI: 10.1111/clr.13591
Effect of different concentrations of commercially available mouthwashes on wound healing following periodontal surgery: a randomized controlled clinical trial. Katsaros T, Mayer E, Palaiologou A, Romero-Bustillos M, Evans GH, Lallier TE, Maney P. Clin Oral Investig. 2020 Feb 19. doi: 10.1007/s00784-020-03232-5. [Epub ahead of print]
Flowcharts for Easy Periodontal Diagnosis Based upon the 2018 New Periodontal classification. Sutthiboonyapan P, Wang HL, Charatkulangkun O. Clin Adv Periodontics. 2020 Feb 19. doi: 10.1002/cap.10095. [Epub ahead of print]
Effect of proton pump inhibitors on bone loss at dental implants. Ursomanno BL et al. Int J Oral Maxillofac Implants 202;35:130-134. DOI: 10.11607/jomi.7800
Association of prosthetic features and peri-implantitis: A cross-sectional study. Yi Yuseung et al. J Clin Periodontol. 2020;47:392–403. DOI: 10.1111/jcpe.13251.
Living cell-based regenerative medicine technologies for periodontal soft tissue augmentation. Mcguire M, Tavelli T, Feinberg F, Rasperini G, Zuchelli G, Wang H, Giannobile W, J Periodontol. 2020;91:155–164. DOI: 10.1002/JPER.19-0353.
Focus on Epithelialized Palatal Grafts. Part 3: Methods to Enhance Patient Comfort at Palatal Donor Sites. Berridge J, Johnson T, Chang A, Swenson D, Miller P. Clinical Advances in Periodontics, Vol. 9, No. 4, December 2019. doi: 10.1002/cap.10066
Tunnel Technique with a Subperiosteal Bag for Horizontal Ridge Augmentation. Karmon B, Tavelli L, Rasperini G., Int J Periodontics Restorative Dent. 2020 Mar/Apr;40(2):223-230. DOI: 10.11607/prd.4508.
Clinical and patient‐centred long‐term results of root coverage using the envelope technique in a private practice setting: 10‐year results—A case series. Petsos, H, Eickholz, P, Raetzke, P, Nickles, K, Dannewitz, B, Hansmeier, U. J Clin Periodontol. 2020; 47: 372– 381. DOI: 10.1111/jcpe.13242.
The effect of the systemic folic acid intake as an adjunct to scaling and root planing on clinical parameters and homocysteine, C-reactive protein levels in gingival crevicular fluid of periodontitis patients. A randomized placebo-controlled clinical trial. Keceli HG, Ercan N, Karsiyaka Hendek M, Kisa U, Mesut B, Olgun E. J Clin Periodontol. 2020 Feb 28. DOI: 10.1111/jcpe.13276.
Treatment of periodontitis reduces systemic inflammation in type 2 diabetes. Preshaw PM, Taylor JJ, Jaedicke KM, De Jager M, Bikker JW, Selten W, Bissett SM. J Clin Periodontol. 2020 Feb 27. DOI: 10.1111/jcpe.13274
Coronally advanced flap and composite restoration of the enamel with or without connective tissue graft for the treatment of single maxillary gingival recession with non-carious cervical lesion. A randomized controlled clinical trial. Cairo F, Cortellini P, Nieri M, Pilloni A, Barbato L, Pagavino G, and Tonetti M. Journal of Clinical Periodontology. 2020; 47:362-371. DOI: 10.1111/jcpe.13229.
Papilla preservation flaps for periodontal regeneration of molars severely compromised by combined furcation and intrabony defects: Retrospective analysis of a registry-based cohort. Cortellini P, Cortellini S, and Tonetti M. Journal of Periodontology. 2020; 91:165-173. DOI: 10.1002/JPER.19-0010
Author: Allen, E.P.
Title: The papilla access tunnel technique for the treatment of shallow recession and thin tissue in the mandibular anterior region
Source: Int J Periodontics Restorative Dent. 2020; 40: 165-169.
Type: technique description
Reviewer: Mary Elizabeth Bush
Keywords: soft tissue augmentation, thin phenotype, gingival thickness, mandibular anterior, recession
Background: The tunnel technique was introduced by A. Allen in 1994 and several modifications have been proposed since that time. It can be difficult to apply a purely intrasulcular approach in areas with shallow recession and limited sulcular access, this is most common in the mandibular anterior where roots are narrow and often have proximity issues. Alternative access techniques are necessary to improve outcomes in this area.
Purpose: To present the papilla access tunnel technique as an alternative to vestibular incisions for soft tissue grafting of multiple teeth with minimal recession in the mandibular anterior region.
Technique: Papilla incision between the lateral and canine on both sides of the anterior region with a #15 blade, creating a 1mm thick surgical papilla and then contacting the alveolar crest. Extend intrasulcular incision from the incised papilla mesial and distal to the line angles of the lateral and the canine. Continue with intrasulcular incisions at central incisors with end-cutting intrasulcular knife, continuing to the lingual line angles to release the papilla. Full thickness mucoperiosteal flap is dissected using a microsurgical elevator, begin at the sulcus adjacent to the incised papilla and extend 4mm apical and lateral to the tissue margin. Continue the full thickness dissection including the centrals approximately 8mm apical to the CEJ. Detach the non-incised papilla from the crest with a Younger-Goode 7/8 curette. Extend the tunnel another 7mm apically with an arrowhead knife while maintaining contact on the bone, creating an immobile bed and release of tissues. The graft (autogenous, allograft or xenograft) is inserted through one of the incised papilla flaps and aligned along the six anterior roots. Overlying tissues and graft are brought coronally to the CEJ and secured with sling sutures (interrupted or continuous), each papilla should be carefully adapted back to its underlying bed.
Discussion: Vestibular access incisions have been advocated as a way to improve bed preparation for tunnel access for treating shallow recession. However, there are limitations in the mandible anatomically with using vestibular incisions. This papilla access technique provides an alternative. The author suggests that greater wound stability can be achieved with a tunnel approach than a traditional envelope or technique using vertical incisions. The biggest challenge to this technique is ensuring the papilla are properly readapted to the bed.
Author: Chen L, Yang T, Yang G, et al.
Title: Retrospective clinical analysis of risk factors associated with failed short implants
Source: Clin Implant Dent Relat Res. 2020; 22: 112-118.
Type: technique description
Reviewer: Mary Elizabeth Bush
Keywords: dental implants, implant location, implant loss, short implants, surface treatment
Background: Insufficient alveolar bone height can create a challenging dilemma for the surgeon. Various methods are available to increase the height of bone but come at the cost of increased surgical time, complications and cost. The alternative option is using short dental implants and a growing number of studies indicate similar success rates of short implants to those of standard length.
Purpose: To perform a retrospective study assessing the underlying risk factors of short implants in a Chinese population.
Methods: In this study short implants were defined as less than or equal to 8.5mm endosseous length, and standard implants were those longer than 8.5mm. A total of 7,001 implants were included in this review, having been placed between 2014-2017, 1,236 were short implants. All implants were from “four mainstream implant systems” and were surface treated either by titanium anodization (TA) or sandblasted, large-grit, acid etching (SLA). Data was collected for each case to look at the implants survival rate and risk factors.
Results: During the observation period 5,765 standard implants were inserted and 106 failed (loss rate 1.84%). A total of 1,236 short implants were included with 45 failures (loss rate 3.64%). The survival of short implants was lower than standard implants (P<.001). The majority of short implants failed at the early stage (38/45) primarily from infection, failure to integrate or undefined reasons. 7/45 short implant failures occurred in the late stage caused by failure of osseointegration and peri-implantitis.
Risk factors evaluated included bone grafting procedure, gender, implant diameter, age, implant location, surface treatment, and splinted restorations. The male group had statistically higher failure than female group (P=.002), the different surface treatment also had significant difference in survival with SLA outperforming TA (P=.002), and the splinted crowns fared better than single crowns (P<.001). On secondary analysis there were also higher failure rate for maxillary molars than mandibular molars, but the difference was not strongly significant (P= .049).
Conclusion: Evidence from this retrospective review found that male gender, TA surface treatment, and single crown restorations are the main risk factors for failure with short implants. Additionally, maxillary molar position may have more challenges than mandibular molar position.
Author: Byun, S.‐H., Kim, S.‐Y., Lee, H., Lim, H.‐K., Kim, J.‐W., Lee, U.‐L., Lee, J.‐B., Park, S.‐H., Kim, S.‐J., Dong Song, J., Seok Jang, I., Kyoung Kim, M. and Kim, J.‐W.
Title: Soft Tissue Expander for Vertically Atrophied Alveolar Ridges: Prospective, Multicenter, Randomized Controlled Trial.
Source: Clin Oral Impl Res. Accepted Author Manuscript. 2020
Reviewer: Hector Carmona
Purpose: to evaluate effectiveness of the novel self-inflating tissue expander for vertical augmentation in terms of soft tissue expansion, clinical outcomes, and related complications.
Methods: 46 Patients who had severe vertical alveolar deficiency and required vertical bone augmentation for subsequent implant placement were screened and enrolled in the study. Experimental groups received vertical incisions of 5 to 10 mm from crest to buccal side were made at each mesial and distal side of the defect. A periosteal elevator was then carefully used to prepare an appropriately sized tunnel beneath the periosteum. Dissection was made through two incisions, connecting the space between the incisions, then the self-inflating soft tissue expander was placed and fixated with a screw on each side to prevent dislocation or movement. After 4 weeks of expansion, a vertical bone augmentation procedure was performed at the same time as the expander was removed. The membrane was tailored according to the size of the removed expander then carefully placed on the expanded mucosa. The bone grafts were performed using xenograft material (Bio-Oss) with the collagen membrane (Cytoplast® RTM collagen membrane). For the control group, the conventional GBR technique with sufficient periosteal releasing incisions was performed to achieve a tension free wound with primary closures. Primary outcome was measured as the amount of augmented soft tissue and the volume amount of augmented bone and retention. As a secondary outcome, clinical complications and thickness changes of expanded gingiva were assessed and analyzed.
Results: Ultrasonographic measurements of gingival thickness above the expanders revealed that the mucosa was not significantly thinned after tissue expansion, that indicates the minimal clinical risk of dehiscence during the expansion. Most patients showed uneventful soft tissue expansion without any inflammatory signs. However, two of them showed over-expansion due to tearing of the silicon envelope, which healed without dehiscence. One of the patients with severe scars owing to previous bone grafting failures showed mucosal perforation during the expansion. Soft-tissue changes after the 4-week expansion period were quantified as 6.88 ± 1.64 mm vertically (measured at buccal) and 6.65 ± 1.38 mm horizontally (measured at 2 mm under CEJ) in the experimental group. After 6 months of GBR, mean values of both vertical and horizontal measurements decreased to 4.58 ± 1.46 mm and 4.63 ± 1.61 mm, respectively, in the experimental group. The control group showed significantly lower values both vertically (3.50 ± 1.08 mm) and horizontally (3.83 ± 1.54 mm) at the same time point.
The radiographic measurements using CBCT right after GBR showed significantly higher vertical bone gain in the experimental group (5.12 ± 1.25 mm) compared to that of the control group (4.22 ± 1.15). After the 6-month retention period, the vertical bone measurement of the control group decreased to the mean value of 1.90 mm (55.0% reduction), which was significantly lower than that of the experimental group with a mean value of 3.55 mm (30.7% reduction). Similar trends were found in the horizontal measurements, but these were not statistically significant.
Conclusion: a self-inflating tissue expander was used to obtain sufficient soft tissue volume gain, which can be attributed to good flap maintenance owing to the presence of adequate and tension-free flaps. Moreover, with this combined treatment modality, favorable hard-tissue integrity was observed with minimal side effects.
Author: Enkling, N., Moazzin, R., Geers, G., Kokoschka, S., Abou‐Ayash, S. and Schimmel, M.
Title: Clinical Outcomes and Bone Level Alterations Around One‐piece Mini Dental Implants Retaining Mandibular Overdentures: 5‐year Follow‐up of a Prospective Cohort Study.
Source: Clin Oral Impl Res. Accepted Author Manuscript. 2020
Reviewer: Hector Carmona
Purpose: To report on the clinical outcomes of one-piece mini-dental implants (MDIs) retaining mandibular implant overdentures (IODs), including marginal bone level alterations, clinical peri-implant parameters, and technical and biological complications during a five-year follow-up.
Methods: Four 1.8 mm diameter one-piece MDIs with ball attachments were placed in the inter-foraminal region of the mandibular arch in 20 edentulous subjects. The existing complete dentures were converted to IODs. Four one-piece MDIs, with a length of 13 or 15 mm and a diameter of 1.8 mm, were placed in the edentulous mandible at the desired positions. The existing dentures were used as a template for the correct positioning of the implants. After raising a mucoperiosteal flap, the bone crest was shortened if necessary, resulting in an approximately equal ridge height and a minimum width of 4 mm. Afterwards, the distal implants were placed at a distance of about 5 mm from the mental foramen and the anterior implants were aligned, resulting in equal inter-implant distances. Radiographs were recorded at BL, 3 months, 6 months, 12 months, 3 years, and 5 years after loading. Clinical peri-implant parameters were recorded at the same appointments except BL. At BL, all evaluations were performed by the prosthodontist delivering the final denture to the participants. Subsequently, examinations were performed by a clinician who was not involved in the surgical or prosthodontic treatment. To evaluate the peri-implant conditions, PDs and the presence of plaque according to the modified plaque index were measured on four sides of each implant using a click-probe. The occurrence of subsequent bleeding (yes/no) was recorded at every follow-up appointment. Additionally, at the first follow-up (3-months) and the final visit (5-years), the width of the keratinized mucosa (KM) at the lingual and the buccal aspects were recorded, and the average was calculated for each implant.
Results: After five years, the mean Changes in marginal bone levels (MBL-diff) were -1.3mm (± 0.8mm) at position 34, -1.2mm (± 0.7mm) at position 32, -1.2mm (± 0.8mm) at position 42, and -1.0mm (± 0.9mm) at position 44. A linear regression analysis demonstrated a significant influence of the time after implant placement on DMBL, but neither the implant position nor patient gender influenced MBL-diff. However, MBL-diff were significantly smaller in participants 65 years or older, compared to patients younger than 65 years. After five years, the mean MBL-diff were 1.5mm (± 0.8mm) and – 0.9mm (± 0.7 mm) in the younger and older cohorts, respectively. The overall implant survival rate was 100%. Furthermore, according to currently accepted implant success criteria (Buser et al. 1991; Misch et al. 2008), the implant success rate was 100%. No major biological complications were observed. However, BOP positive sites were detected at every follow-up visit. In six patients, the denture fractured twice, and in one further patient, the denture fractured three times, resulting in a total of 15 denture fractures (35% at subject level).
Conclusion: One-piece MDIs retaining a mandibular IOD by means of O-ring attachments are a predictable treatment option, providing stable peri-implant bone conditions, over a mid-term follow-up. The presence of keratinized mucosa does not necessarily lead to decreased bone-level changes.
Author: Katsaros T. et al.
Title: Effect of different concentrations of commercially available mouthwashes on wound healing following periodontal surgery: a randomized controlled clinical trial.
Source: Clin Oral Investig. 2020 Feb 19.
Reviewer: Hillary Wright
Keywords: periodontal surgery; healing; mouth rinse
Background: Effectiveness of both chlorhexidine (CHX) and essential oil (EO) mouth rinses are well documented being anti-plaque and anti-gingivitis. There is concern that both of these mouth rinses can have negative effects on gingival fibroblast’s morphology, viability, and function. Importance of fibroblasts in wound healing is well recognized.
Purpose: to evaluate the effect of chlorhexidine and essential oils containing mouth rinses on oral wound healing after periodontal flap surgery.
Methods: 80 systemically healthy patients scheduled to undergo periodontal surgery were included. All patients received non-surgical therapy and OHI prior to surgery and then randomly selected into 1 of 5 groups: control group (water as mouth rinse), 4 test groups (.12% CHX, EO, 5% dilution of .12% CHX and 10% dilution of EO). Instructions of use 15ml BID for 30 seconds beginning the day after surgery for 2 weeks. No other OH was done in the quadrant treated until week 3, then soft bristle toothbrush was able to be used. Sutures removed at 2 weeks and further examination at 3 weeks. Clinical examination and indices included debridement of the surgical site and recording of plaque index and modified gingival index. Secondary intention healing observed at the first visit was measured with a probe and at any subsequent examination until complete closure achieved.
Results: 59/80 patients completed the study. NSSD found for modified gingival index parameter between the groups. Plaque index showed significant difference between 10% EO vs. water, CHX vs. water, EO vs water, and 5% CHX vs. water. The water group had higher PI when compared to different mouthwash groups at week 1 visit. At the second visit, EO vs water, CHX vs. water, and water vs. 5% CHX still showed significant differences. At 3 weeks post-surgery, significant differences were still shown between CHX and water. Wound healing evaluation: Week 1, CHX group had 100% of wounds open. 5% CHX had 46.15% wound opening, EO: 35.71% wound opening, 10% EO: 81.82% wound opening, and 33.33% wound opening in the water group. At weeks 2 and 3, there was no significant relation found.
Conclusion: This clinical trial and follow-up study from the in vitro study showing CHX had detrimental effect on the survival of fibroblasts as well as their migratory capacity, showed better plaque control of 5% CHX and greater antibacterial effect of 10% EO. CHX group achieved the lowest plaque index after 3 weeks post-surgery after oral hygiene regimen was reinstated. Neither mouth rinses showed any detrimental effects clinically.
Author: Sutthiboonyapan P. et al.
Title: Flowcharts for Easy Periodontal Diagnosis Based upon the 2018 New Periodontal classification.
Source: Clin Adv Periodontics. 2020 Feb 19.
Reviewer: Hillary Wright
Keywords: periodontal diagnosis; periodontal classification
Purpose: to present a simple flowchart for periodontal diagnosis using the new classification system.
Discussion: The goal of these flowcharts (depicted below) is designed for quick initial screening to make proper diagnosis for the three most commonly found periodontal conditions: health, gingivitis, and periodontitis. Diagnosis includes both new cases and previously treated periodontal cases. Once periodontal stability is achieved, health or gingivitis can exist on a reduced periodontium with clinical attachment loss (CAL). If signs of active periodontitis remain after treatment, diagnosis of recurrent periodontitis is made due to the unsuccessful treatment.
Probing depth is the first parameter used to categorize the patient, followed by percentage of BOP. Periodontal health: PD </= 3mm and full mouth BOP <10%. If PD is </= 3mm but BOP >10%, then detection of radiographic bone loss (RBL) or CAL will be needed to further categorize. If no RBL or CAL, then patient will be categorized as gingivitis case. A case with RBL and CAL, history of periodontal treatment is needed for diagnosis. Previously treated: gingivitis on a reduced periodontium in a stable-periodontitis patient. If no treatment: periodontitis case. If maximum PD >3mm and BOP <10% without RBL or CAL= periodontal health.
PD>3mm, BOP >/=10%, no RBL or CAL=gingivitis
PD>3mm, BOP >/= 10%, RBL or CAL= periodontitis
In addition to PD=4mm, BOP <10% with RBL or CAL, history of periodontitis = health on a reduced periodontium in a stable periodontitis patient. * PD=4mm can still be present in a periodontitis case that has been successfully treated. PD=4mm, without history or periodontitis or PD>/= 5mm= periodontitis diagnosis.
PD>/=5mm even with <10% BOP= periodontitis.
Once a case is classified as periodontitis, diagnosis is confirmed with either 1. Interdental CAL detectable at >/=2 non-adjacent teeth or 2. Buccal or oral CAL >/=3mm with pocketing >3mm detectable at >/=2 non-adjacent teeth.
Next, severity of periodontitis uses staging system. Tooth loss from periodontitis, including teeth planned for extraction due to periodontitis are recorded. If tooth loss existed, then the case is stage III or IV. The difference between stage III and IV is based on the number of tooth loss and masticatory dysfunction.
Stage IV: tooth loss due to periodontitis >/=5, and/ or less than 20 remaining teeth, and/or need of rehabilitation because of masticatory dysfunction.
Stage III: <4 teeth loss due to periodontitis.
If no tooth loss or loss due to other causes than periodontitis, combination of CAL, PD, and RBL used to classify the patient.
CAL >/=5mm, and/or PD >/=6mm, and/or vertical bone loss >/=3mm, and/or furcation involvement grade 2 or 3, the case is either Stage III or IV.
CAL <5mm, and/or PD <6mm, the case is either Stage I or II.
Periodontitis grade is used to determine the rate of disease. Grade B is the default for most periodontal cases. Primary criteria for grade identification is evidence of disease progression, either direct longitudinal evidence over 5 years of RBL or CAL or indirect evidence, a calculation of % bone loss/ age.
Grade A: % bone loss/age <0.25, no evidence of disease progression
Risk factors to consider are diabetes and smoking.
Author: Ursomanno, BL et. Al.
Title: Effect of proton pump inhibitors on bone loss at dental implants
Source: Int J Oral Maxillofac Implants 202;35:130-134
Type: retrospective study
Reviewer: Thao Nguyen
Keywords: bone loss, dental implants, proton pump inhibitor
Purpose: to determine if bone loss severity at dental implants could be associated with proton pump inhibitors (PPI) use.
Methods: Dental, medical, and radiographic history records of patients receiving dental implants at the University at Buffalo, School of Dental Medicine from 2000 to 2017 were reviewed. PPI use was confirmed by medical record examination. The effects of systemic factors were assessed (smoking, diabetes, systemic steroids, hormonal replacement therapy, chemotherapy, or autoimmune disease such as thyroiditis, lupus, or rheumatoid arthritis). A sequential time series pair of radiographs were reviewed for each implant by a single examiner. The initial assessment (T1) was obtained at the time of implant placement, where apparent implant length was measured from the most crestal to the most apical aspect of the implant in mm. A subsequent radiograph with the greatest available elapsed time between placement and implant re-evaluation (T2) was used to again obtain implant length and bone loss measurements. Crestal bone loss was also measured by counting the number of exposed implant threads at each implant at T2 and subtracting that from the number of exposed threads at time of placement. Implant failure in this study was defined as implant that lost integration and required removal.
Results: Mean radiographic evaluation time intervals ranged from 2.57 years to 3.26 years for bone loss in mm assessment group and 2.79 years to 3.80 years for exposed threads assessment group. Overall failure rate was 2.5% (35 out of 1,430 implants. Patients taking PPIs experienced a 5.5% failure rate (11 of 210 implants) as opposed to 2.0% failure rate (24 of 1,299) in non-PPIs group.
A total of 1,480 implants from 635 patients were used in this study. The majority of implants were Straumann, Nobel BioCare and Astra. Greater crestal implant bone loss was associated with patients with a history of PPI medication use. Mean crestal bone loss of 1.60 mm was noted at implants from PPI patients, in contrast to 1.01 mm of crestal implant bone loss among the non-PPI group (58.4% increase). Following adjustment for systemic factors, crestal implant bone loss of 1.87 mm from PPI patients, in contrast to 1.04 mm from non-PPI patients (79.8% increase).
0.63 exposed threads per implant were found in the PPI group, and 0.38 supracrestal implant threads in the non-PPI patient (mean difference = 0.25 exposed threads, 65.8% increase). After excluding systemic factors, a similar pattern was observed with 0.79 vs 0.36 threads exposed from subjects taking PPIs, compared with those not taking PPIs, respectively (mean difference = 0.43 exposed threads, 119.4% increase).
Discussion: The results suggest that PPI medications are related to significantly more crestal bone loss at dental implants and a higher implant failure rate. Further prospective clinical trials are necessary to provide recommendations regarding implant placement in patients taking PPIs, as well as to quantify the amount of bone loss directly attributable to those medications.
Author: Yi Yuseung, et. al.
Title: Association of prosthetic features and peri-implantitis: A cross-sectional study
Source: J Clin Periodontol. 2020;47:392–403
Type: cross-sectional study
Reviewer: Thao Nguyen
Keywords: emergence angle, emergence profile, peri-implantitis, restoration contour, splinted.
Purpose: to identify the influence of prosthetic features through a comprehensive analysis with other known risk factors.
Methods: This retrospective study included a total of 349 implants in 169 patients who were treated with implant restorations at Seoul National University Dental Hospital between March 2002 and February 2012. Exclusions criteria include systemic diseases, smokers, irregular maintenance care, full mouth plaque score ≥25%, implants placed on reconstructed jaw after jaw resection, implant-assisted removable prosthesis, implants with fracture components, failed implants, implants re-installed after failure, previously treated peri-implantitis. Peri-implantitis was diagnosed where, in comparison with the initial examination at the first year following prosthesis insertion, a radiographic measurement of bone loss superior to 0.5 mm was concomitant with an increased PD, BOP and/or suppuration. Using radiographs taken both at 1 and 5 years following prosthesis insertion, the following features were determined: peri-implant marginal bone loss (MBL), emergence angle (EA), emergence profile (EP) and crown/implant ratio (CIR). The splinted position of prosthesis was also recorded. EA was defined as the angle between the tangent of the transitional contour relative to the long axis of the implant. EP, the contour of a restoration, was classified as concave, straight and convex. The splinted position of implant prosthesis was recorded: single: restored independently; splinted-mesial: the mesial implant splinted with the distally adjacent implant; splinted-middle: the middle implant splinted with both the mesially adjacent implant and the distally adjacent implant; and splinted-distal: the distal implant splinted with the mesially adjacent implant. Multivariable generalized estimating equation was used to analyze the influence of each feature on the prevalence of peri-implantitis.
Results: The mean MBL was 1.20 ± 1.34 mm, and 173 implants were affected by peri- implantitis (24.8%). The mean EA was 27.9 ± 14.2 degrees, and there was no significant difference between the frequency of EA below 30 degrees and above 30 degrees. The most frequent EP was convex (46.7%), followed by straight (32.2%) and concave (21.1%). The number of implants in the posterior region was higher than that in the anterior region, regardless of the arch position. The mean diameter of implants was 4.35 ± 0.53 mm, and the mean lengths of implants were 10.78 ± 1.52 mm. The EA showed a significant correlation with MBL. A statistically greater prevalence of peri-implantitis was observed if EA ≥ 30 degrees, when EP is convex and in middle implant splinted with both mesial and distal adjacent implants in bone- level implant. the risk of peri- implantitis was significantly raised with the increase in the EA (OR 1.04). As dichotomous variables, a significantly higher MBL and the prevalence of peri-implantitis were detected with EA ≥ 30 (OR 3.80). A similar correlation was not observed in tissue-level implants. No significant differences were found in both the MBL and the prevalence of peri-implantitis between implant manufacturers. CIR had no significant effect on the prevalence of peri-implantitis.
Discussion: The risk of peri-implantitis was significantly raised with the increase in EA, and convex profile was an important local confounder for peri-implantitis. The implant splinted to both adjacent implants has a high risk of peri-implantitis. Based on this research, over-contoured restoration should be avoided, and a careful selection of the fixture is required. A wider diameter or a deeper position of the implant would lead to a smaller EA of the restoration. Raising the contact point with the adjacent tooth or in the splinted implant prosthesis from gingival to occlusal surface could widen the interproximal area, facilitating plaque control.
Author: McGuire M, Tavelli T, Feinberg F, Rasperini G, Zuchelli G, Wang H, Giannobile W
Title: Living cell-based regenerative medicine technologies for periodontal soft tissue augmentation
Source: J Periodontol. 2020;91:155–164
Reviewer: Maggie Weber
Keywords: gingival recession, periodontal, regenerative medicine, soft tissue grafting, tissue engineering, tissue scaffolds
Background: Advantage to living-based cell-based technology is the ability to communicate with host by modulating cytokine expression.
Purpose: A review to present the characteristics and clinical application of cell-based constructs for root coverage and soft tissue augmentation.
Fibroblast-based constructs– A living dermal graft is made by cultivating neonatal human fibroblasts on a bioabsorbable polyglactin mesh. These fibroblasts secrete growth factors and proteins – including collagen, fibronectin, glycosaminoglycans, and cytokines. This allows for a metabolically active structure that can serve as both a scaffold and as a wound healing agent. Therefore, it has been used in studies by Koseoglu, Jhaveri, Pini-Prato and, Izumi, for the treatment of recession.
Keratinocyte-based constructs- An ex-vivo produced oral mucosal equivalent is a living cellular construct made by autogenous keratinocytes taken from a punch biopsy then purified and cultivated on ADM. A well-differentiated epidermis was seen at the 11-18 day mark. It releases growth factors to promote both early vascular invasion and revascularization. Therefore, it has been used in studies by Izumi, and Hotta, for the treatment of: a lack of KT, gingival recession, and mucosal reconstruction after biopsy.
Fibroblast-Keratinocyte Based Combination constructs- Reasoning behind using a construct with two cell types is that dermal fibroblasts are responsible for homeostasis of the extracellular matrix (needed for keratinocyte growth and differentiation) while keratinocytes create the external epithelial layer as an effective barrier. Cytokines and growth factors – like BMPs, FGF, PDGF, VEGF – are different than those made from only one cell type. Hence, both keratinocytes and fibroblasts are needed for a fully developed epithelium.
Keratinized-Tissue Width Augmentation- Pini-Prato has a study in patients requiring KT augmentation. Fibroblasts were collected from the gingiva of these patients and placed on HA matrix. After 3 months, grafted site was epithelialized with an average of 2mm KT.
McGuire compared TEC as an alternative to FGG. Histology at 6 months showed similar CT covered by keratinized epithelium and the CT was more organized than the FGG. Dermal graft had better color match. Dermal graft also showed more angiogenic biomarkers. However, dermal graft showed much more shrinkage (2.7mm) than FGG. Overall KT gain was inferior to FGG. KT gain was 3.2mm in dermal versus 4.6mm in FGG. But authors still state it is a good alternative to FGG for KT width gain.
Root Coverage Procedure- According to Cairo and Chambrone, xenogenic and human-derived scaffolds failed to provide same outcomes as CTG in terms of root coverage. Wilson conducted a study comparing dermal replacement graft to CTG and found similar results to CTG and TEC. Complete root coverage with TEC obtained only when material completely covered by flap. Milinkovic compared CTG to TEC and found similar esthetics and root coverage between the two, but CTG had more KT width gain.
Koseoglu compared TEC to ADM and found considerably more root coverage with TEC. Jhaveri compared TEC to ADM and found similar results for both ADM and TEC.
Zanwar compared marrow-derived mesenchymal stem cells (from umbilical cord) to CTG and found CTG had greater root coverage but TEC had greater CAL gain.
Conclusion: Living cellular constructs can be used in augmenting KT. It shows improved esthetics, lower morbidity, and higher patient preference (no palatal site) compared to autogenous grafts. Overall, autogenous grafts are still superior in KT width augmentation and root coverage.
Author: Berridge J, Johnson T, Chang A, Swenson D, Miller P
Title: Focus on Epithelialized Palatal Grafts. Part 3: Methods to Enhance Patient Comfort at Palatal Donor Sites
Source: Clinical Advances in Periodontics, Vol. 9, No. 4, December 2019
Type: case series
Reviewer: Maggie Weber
Keywords: Autografts; gingiva; palate; pain management; treatment outcome; patient outcome assessment
Background: Near the palatine raphe and also close to the maxillary teeth, the oral mucosa of the hard palate lacks a distinct submucosa – instead they have mucoperiosteum with dense collagen. Between these two zones, there is a submucosa that contains loose CT, adipose, glands, vessels, and nerves (MX division of trigeminal via greater palatine and nasopalatine).
Purpose: Part 3 of a case series that studies postoperative discomfort following epithelialized palatal grafts (EPG) using local measures and systemic analgesics.
Case 1: The patient is a 53 year-old with good systemic health having supraeruption of his mandibular incisors and recession type-2 defects at teeth 23-26. The patient received EPG at sites 23-26 under moderate IV sedation (midazolam, fentanyl, dexamethasone). A bilateral EPG of about 2.5mm in thickness were harvested. A collagen membrane was placed over the donor site using 4-0 polytetrafluoroethylene sutures. The patient received ibuprofen 800mg every 4 hours as needed for post-op pain. The patient was also given a rigid palatal stent to protect collagen membrane. The patient was recommended to use warm saltwater rinses, as well. The patient stated minimal palatal pain – pain at grafted mandible site was worse.
Case 2 and 3: The patients were two females, 54 and 29 years-old, with RT1 and RT2 recession types over the mandibular anterior teeth. The same technique was used for the donor sites as was used in case 1.
Patient 1 stated minimal palatal pain during first few days and no pain at palate by day 7. Patient 2 stated moderate pain from palate during the first week and no pain at palate by day 14.
Conclusion: Collagen membranes may effectively minimize donor site pain. In addition, when IV sedation is used, a steroid can be used as an anti-inflammatory and analgesic effect.
Author: Karmon B., Tavelli L., Rasperini G.
Title: Tunnel Technique with a Subperiosteal Bag for Horizontal Ridge Augmentation.
Source: Int J Periodontics Restorative Dent. 2020 Mar/Apr;40(2):223-230.
Type: Case Study
Reviewer: Ronald Young
Keywords: horizontal ridge augmentation, guided bone regeneration, tunnel, xenograft, Bio-Oss, Bio-Gide
Purpose: To describe a tunnel technique with a subperiosteal bag for horizontal GBR, highlighting its main advantages through a case presentation.
Methods: Healthy patients were selected that required horizontal ridge augmentation for implant rehabilitation with adequate vertical height but deficient laterally. CBCT was taken 6 months prior to surgery, and surgery was carried out using a bilayer resorbable collagen membrane (Bio-Gide) and a bovine-derived xenograft bone substitute (Bio-Oss). The membrane was extra orally perforated, folded and sutured with a resorbable suture to create a “bag” with an opening. Bag was perforated with a punch only on one side. For a defect located in the maxilla, a vertical incision was performed on the buccal mucosa mesial to the ridge defect. Blood from the incision was used to soak the bone particles, which were then placed inside of the bag and closed with a resorbable suture. 20cm of the suture and needle were left extending from the bag. A vertical incision and subperiosteal tunnel were made with elevators, dissection extended beyond bone deficiencies and at the level of the crest. After a sufficient tunnel as achieved the suture and needle were used to pull the bag into the tunnel and not fixated. For a defect in the mandible a lingual subperiosteal tunnel was made and connected through the region to a buccal subperiosteal tunnel at the lingual aspect of mandibular anterior teeth. The bag was slid in through the lingual access, then over the crest and into its final location in the buccal aspect of the mandible. Patients were given antibiotics, naproxen sodium, chlorhexidine rinse, and no oral hygiene for 4 weeks. Patients recalled at 1, 3 and 6 months and analyzed by a CBCT.
Case 1: 53-year-old woman with missing maxillary left premolars and molars presented with horizontal deficiency. After a subperiosteal tunnel flap preparation including a vertical incision above the lateral incisor, the membrane was folded, sutured into a bag, and filled with xenograft soaked in the patient’s blood. A resorbable suture was placed into the tunnel, and through the distal of the tunnel allowing proper placement of the bag in the tunnel. Soft tissue healing was uneventful, and six months after the procedure the CBCT was taken to plan implant placement showing bone volume gain at the augmented site.
Case 2: 72-year-old woman with severe osteoporosis and missing maxillary left premolars and molars presented with horizontal deficiency. Bag was prepared and filled with xenograft, tunnel technique for horizontal GBR performed with vertical incision on the facial of the canine. Subperiosteal tunnel formed and suture use to close the bag and pull it into place in the tunnel. Post-operative healing was uneventful and 6-month CBCT showed a significant increase in horizontal bone dimension compared to baseline.
Case 3: 58-year-old woman presented with missing mandibular second premolar and molars with horizontal deficiency. A tunnel approach with a facial vertical incision at the mesial of the canine was performed with a full-thickness flap elevation on the lingual side to allow a subperiosteal tunnel from the buccal to lingual aspects. Membrane was folded, sutured, filled with xenograft soaked in patient’s blood. Bag was inserted into the tunnel as describe previously, bag was manipulated over the ridge and into the buccal aspect with the perforated side facing bone and fixated with 2 titanium tacks. Incisions were sutured, and after 6 months the CBCT showed significant horizontal bone gain compared to the initial scan. Bone gain was confirmed at re-entry.
Discussion: Due to the extreme importance of healing via primary closure in horizontal GBR, a tunnel-like approach avoids the vertical releasing incisions which minimize tissue trauma, enhance blood supply, and obtain uneventful healing. This technique has been associated with less dehiscence and lower morbidity than traditional GBR. Along with the lower number of postoperative visits and surgical procedures, and adequate horizontal ridge dimension that can be obtained that it should be considered alongside traditional methods. This technique keeps an intact periosteal layer to contribute to bone regeneration and osteoinductive properties.
Conclusion: In these illustrated cases, this novel technique results in a significant horizontal bone gain that allowed for implant placement after healing.
Author: Petsos, H, Eickholz, P, Raetzke, P, Nickles, K, Dannewitz, B, Hansmeier, U.
Title: Clinical and patient‐centered long‐term results of root coverage using the envelope technique in a private practice setting: 10‐year results—A case series.
Source: J Clin Periodontol. 2020; 47: 372– 381.
Type: Long Term Case Study
Reviewer: Ronald Young
Keywords: connective tissue graft, envelope technique, Oral Health Impact Profile (OHIP), patient-centered outcomes, root coverage
Purpose: To generate clinical and patient-centered long-term results following envelope technique application in a private practice setting.
Methods: 16 patients who had been reported on at 3 months post root coverage with an envelope technique were re-examined at 120 months. Inclusion criteria: Miller class 1 or 2 defect, adult, absence of probing depth greater than 5mm, less than 35% plaque index. Surgery technique is as described by Hansmeier and Eickholz 2010: after root scaling was completed a 0.5mm margin was excised around the recession followed by the preparation of an envelope undermining the circumferential and supraperiosteal tunnel preparation around the recession. At the palatal harvest site, a paramarginal incision was made 2mm from the gingival margin and premolars, a second parallel incision was made 1-2mm more palatally at least twice the length of the recession. Epithelial margin was removed, CTG placed into the envelope with at least 50% of the graft submerged in the envelope. Histoacryl was used to fix the tissue, site was covered with dressing. Post surgically patients were asked to refrain from plaque control for 1 week, rinse with chlorhexidine. Sutures removed after 1-week, oral hygiene instruction given and placed on maintenance at least once per year. Examinations were completed at baseline, 3-months, and 120 months after surgery. Measurements recorded: recession depth (RD), recession width (RW), width of keratinized gingiva (GW), and patients were classified as either non-smokers, former smokers, or active smokers. Patient-centered parameters recorded: esthetics, hypersensitivity, root caries, and several questions related to the morbidity and satisfaction with the outcomes.
Results: 15 patients with maxillary Miller Class 1 recessions participated in the study. 3 were former smokers, all others were non-smokers. PD (probing depth) at 3 months increased at 120 months by 0.5mm. RD at 3 months decreased by 0.5mm, RW and GW at 3 and 120 months remained stable. Average relative root coverage (RC) increased significantly to 75% after 120 months compared with 40% after 3 months. The number of cases with complete root coverage rose from 2 (15%) at 3 months to six (40%) at 120 months. Linear regression analysis showed a SSD between RD and GW after 3 months based on the change in RC from 3-120 months. 80% of patients said they would undergo the procedure again, 93% had satisfaction and perceived improvement by the final results. NSSD between patient scores from the final result after 10 years compared with 3 months.
Discussion: Root coverage with CTG using the envelope technique leads to a clinically stable result over 10 years in a private practice setting. Th envelope technique also leads to stabilization of the improved OHIP values over a period of 10 years. Overall, 93% of patients were satisfied with the results after a 10-year period.
Author: Keceli HG, Ercan N, Karsiyaka Hendek M, Kisa U, Mesut B, Olgun E.
Title: The effect of the systemic folic acid intake as an adjunct to scaling and root planing on clinical parameters and homocysteine, C-reactive protein levels in gingival crevicular fluid of periodontitis patients. A randomized placebo-controlled clinical trial
Source: J Clin Periodontol. 2020 Feb 28.
Reviewer: Brian Goldfarb
Keywords: periodontitis, folic acid, periodontal treatment, gingival crevicular fluid, C-reactive protein, homocysteine
Purpose: To evaluate the effect of systemic FA-supplement to SRP in patients with stage II-III periodontitis via clinical and biochemical outcomes.
Methods: Study was designed as a double blind, placebo- controlled, single centered, 60month follow up random control trial. Sixty patients with periodontitis were included in the study. Based on a clinically and radiographic exam, the patient’s periodontal status was determined. Patients with at least 8 pockets of >5mm, CAL >4mm and radiographic stage 2-3. Patients with significant systemic diseases were excluded. Full-mouth exam completed and standardized OHI. Measurements were taken at baseline and 1,3,6-month post treatment. Clinical measurements include plaque index, gingival index, PPD, gingival recession, CAL. Within 15 days of exam, SRP was scheduled. SRP completed under local anesthesia and with manual and ultrasonic devices in a single appointment. Adjunct given randomly among subjects, immediately after SRP. Those in experimental group received FA tablets (400mcg, folic-plus [contain folic acid, calcium, vitamin D3]). Patients in control group received placebo tablets. Patients instructed to wake 3 times a day for 4 weeks. Blood samples were tested for Serum FA, GCF and biochemical analysis.
Results: 37 patients completed the study, with 17 SRP and placebo control group and 20 in the SRP and FA experimental group. Both groups demonstrated similar baseline PI, GI, PPD, GR and CAL. Serum FA analysis. FA group showed significant better results than placebo group. FA intake with SRP showed enhanced attachment gain compared to placebo.
Conclusion: Folic Acid inadequacy has been linked to many biological effects such as oxidative stress, endothelial dysfunction, deficiency in DNA repair and cellular apoptosis that may interfere with host response. Hcy can increase protein circulation of oil-6, TNF-a from inflamed tissue. Hcy has also been found to be elevated in FA deficiency. It was found that with the increase in folic acid leading to decrease in Hcy lead to greater attachment gain.
Author: Preshaw PM, Taylor JJ, Jaedicke KM, De Jager M, Bikker JW, Selten W, Bissett SM
Title: Treatment of periodontitis reduces systemic inflammation in type 2 diabetes
Source: J Clin Periodontol. 2020 Feb 27.
Reviewer: Brian Goldfarb
Keywords: inflammation; periodontitis; diabetes mellitus; diabetes mellitus, type 2
Purpose: To investigate the effects of periodontitis treatment of periodontal and systemic inflammation in individuals with and without diabetes.
Methods: Adults with type 2 diabetes were recruited. Periodontal exams were completed, including plaque index, modified gingival index, full mouth probing and BOP. Subjects were given diagnosis according to the Armitage 1999 classification. Blood samples obtained from all subjects at baseline and 3,6,12 months after treatment. Statistical analysis was completed.
Results: 83 patients with diabetes and 75 without diabetes were included. No significant difference between baseline age, gender, ethnicity, smoking. Patients in type 2 diabetes group had a higher BMI on average. 6 subgroups, diabetes/periodontal health, diabetes/gingivitis, diabetes/periodontitis, no diabetes/periodontal health, no diabetes/gingivitis, and no diabetes/periodontitis. Diabetic healthy individuals had A1c of 6.3. Diabetic gingivitis had A1c of 7.0 and diabetic periodontitis had A1c of 7.5. No difference in baseline Il-6 and TNF-A between groups.
At baseline, individuals with diabetes and periodontitis had significantly higher systemic inflammation compared to non-diabetic controls with periodontitis as assessed using the latent variable systemic inflammation. However, there were no significant difference for oral inflammation. 12-month post-treatment changes in oral inflammation were comparable in periodontitis sufferers with and without diabetes. periodontitis treatment resulted in significantly greater reductions in systemic inflammation in individuals with diabetes and periodontitis compared to those with periodontitis only. Groups were compared based on BMI to eliminate BMI as a factor for greater reduction of systemic inflammation however once adjusted BMI was not significant.
Conclusion: The treatment of periodontitis in individuals with type 2 diabetes were found to lower systemic inflammation more significantly than patients without diabetes. Both groups of patients with or without diabetes saw a significant reduction in oral inflammation with treatment of periodontitis.
Authors: Cairo F, Cortellini P, Nieri M, Pilloni A, Barbato L, Pagavino G, and Tonetti M.
Title: Coronally advanced flap and composite restoration of the enamel with or without connective tissue graft for the treatment of single maxillary gingival recession with non-carious cervical lesion. A randomized controlled clinical trial
Source: Journal of Clinical Periodontology. 2020; 47:362-371
Type: Clinical trial
Reviewer: Eugene Rowell III
Keywords: aesthetics, connective tissue graft, coronally advanced flap, gingival recession, multiple gingival recessions, root coverage
Purpose: To compare CTG plus CAF versus CAF alone for root coverage at single maxillary gingival recessions with previously restored NCCL.
Methods: The present study is a parallel, randomized clinical trial on the treatment of single recession at maxillary arch associated with NCCL. Patients had to exhibit a single RT1 buccal gingival recession accompanied by a NCCL. All NCCLs were treated with a composite filling to reconstruct enamel/CEJ prior to surgery. All surgeries were performed by one clinician. Baseline parameters were recorded for all participants. After local anesthesia, two oblique, divergent releasing incisions extending beyond the MGJ were performed. A split-full-split thickness flap was raised-up beyond the MGJ. A gentle root debridement was performed using a sharp curette up to 1 mm from the bone crest. CTG usage was randomly assigned during the procedure. The flap was then coronally displaced 1–2 mm above the restored CEJ in both test and control groups.
Results: A total of 30 patients exhibiting single gingival recession associated with NCCL in the upper arch participated in the study. 14 patients in the test group (CAF + CTG) and 16 in the control group (CAF only). Duration of the procedure was on average 17 mins shorter for the control group. After 12 months, both procedures were similar in term of final RecRed and CRC with no significant difference between test and control groups. Rec with GT ≤ 0.84 mm the use of CTG under CAF yielded to higher RecRed, while for GT > 0.84 the flap alone was associated with better outcomes. A significant interaction between type of treatment and final RES score was also detected, showing that for baseline GT value ≤0.82 mm CAF + CTG provided higher RES scores, while for values >0.82 mm the use of CAF alone was associated with better aesthetic outcomes. The addition of a CTG under CAF was associated with a significant increase in apico-coronal KT. CAF alone does not seem to be able in promoting significant KT changes compared with baseline conditions.
Conclusion: Both procedures were effective for root coverage at single RT1 recession with restored NCCL and limited horizontal step. Higher post-operative morbidity was reported for CAF + CTG group. CAF + CTG overall is more effective than CAF alone in recessions with thin gingival phenotype (<0.8 mm) and use of CTG might be selectively limited to these cases. The use of CAF alone provided better aesthetic outcomes rated by RES score in recessions with well represented GT (>0.8 mm), thus suggesting caution in an excessive thickening of baseline KT.
Authors: Cortellini P, Cortellini S, and Tonetti M.
Title: Papilla preservation flaps for periodontal regeneration of molars severely compromised by combined furcation and intrabony defects: Retrospective analysis of a registry-based cohort
Source: Journal of Periodontology. 2020; 91:165-173
Type: Retrospective study
Reviewer: Eugene Rowell III
Keywords: intrabony defect, molar furcation, periodontal regeneration, periodontitis, tooth survival
Purpose: To describe specific designs for papilla preservation flaps (PPFs) and minimally invasive surgery to be used in the management of compromised molars; and report proof-of principle data with 3 to 16-year follow-up of cases extracted from a prospective registry of periodontal regeneration from the authors’ practice.
Methods: A total of 49 patient each exhibiting one defect was used in this study. Teeth used had to have at least one furcated first or second molar (class II or III), PD and CAL >6mm, and intrabony defect deeper than 3mm. All teeth were treated with periodontal regeneration with PPF according to a minimally invasive surgical approach. Clinical parameters and radiographs were taken at baseline. Defects were classified after flap elevation. A horizontal incision according to the principles of the modified papilla preservation technique was traced at the buccal aspect of the defect associated papilla when the width of the interdental space was >2 mm, while a diagonal incision was applied when the interdental space was 2 mm or narrower. The full-thickness flaps were elevated to expose the crest of bone surrounding the intrabony defect and to gain access to the involved interradicular space. Defects were thoroughly debrided. All surgeries were performed with magnification using an operating microscope and microsurgical instruments by a single operator. After completion of active treatment, subjects were enrolled in an individualized supportive periodontal care program. Improvement as a consequence of therapy was defined as tooth retention, reduction in horizontal and vertical furcation involvement, decrease in probing depths, and increases in clinical attachment level.
Results: Mandibular molars: MMIST was used in nine cases and a more extended flap in an additional four cases. Changes from baseline to the 1-year follow-up show 100% tooth survival, improvement of both horizontal and vertical furcation classification along with improvements in clinical AL and PD. 84.6% of cases showed improvement in vertical subclassification. During maintenance, 3 to 8 years post-op, two teeth displayed worsening of the horizontal and vertical furcation involvement and were extracted, both exhibited hypermobility at baseline.
Maxillary molars: M-MIST was used to access the defects in six cases. These were characterized by improvements in horizontal and vertical furcation involvement and improvements on periodontal probing parameters at the 1-year follow-up. 87.5% of cases showed improvement in vertical subclassification at 1 year. One case demonstrated deterioration of the furcation involvement during the maintenance phase, 3 to 16 years post-op.
Conclusion: This study shows that significant clinical improvements can be achieved by applying periodontal regeneration to complex intrabony defects combined with furcation involvement in both maxillary and mandibular molars. These results can be used to design and test effective molar retention strategies, avoid early extraction of compromised molars, and help preserve masticatory function extending to the molar area.