151-152. Furcation Therapy                                    

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Rapid Search Topics:

1. etiology of the furcation involvement
2. incidence and distribution of furcation involvement
3. location of furcation entrances
4. furcation anatomy and dimensions
5. incidence and distribution of root fusion
6. the impact of restorative dentistry on furcation involvement
7. cervical enamel projections and correlation with furcation involvement
8. debridement as treatment for furcation involvement
9. tunneling as treatment for furcation involvement
10. root amputation and hemisection
11. chemical root treatment in furcation therapy
12. using barriers for furcation treatment
    1. non-resorbable membranes
    2. resorbable membranes

Discuss the etiology, incidence, and distribution of furcation invasions. Discuss the diagnosis and prognosis of furcation invasions by tooth type and compare to single rooted teeth. What role does root anatomy play in the etiology and management of furcation defects?

1. Waerhaug J. The furcation problem. Etiology, pathogenesis, diagnosis, therapy, and prognosis. J Clin Periodontol 7:73-95, 1980.

2. Ross IF, Thompson RH: Furcation involvement in maxillary and mandibular molars. J. Periodontol. 51:450-454, 1980.

3. Dunlap RM, Gher ME. Root surface measurements of the mandibular first molar. J Periodontol 56:234-238, 1985.

4. Gher MW Jr, Dunlap RW. Linear variation of the root surface area of the maxillary first molar. J Periodontol.1985;56(1):39-43.

5. Hou G, Tsai CC. Types and dimensions of root trunk correlating with diagnosis of molar furcation involvements. J. Clin. Periodontol. 1997; 24: 129-135

6. Ward C, Greenwell H, Wittwer JW, Drisko C. Furcation depth and interroot separation dimensions for 5 different tooth types. Int J Perio Rest Dent 1999;19:251-257.

7. Paolantonio M, Placido M, Scarano A, Piatelli A. Molar root furcation: Morphometric and morphologic analysis. Int J Perio Rest Dent 1998;18:489-501.

8. Ross IF, Evanchik PA: Root fusion in molars: incidence and sex linkage. J Periodontol 52:663-667,1981.

9. Hou G, Tsai C, Huang J. Relationship between molar root fusion and localized periodontitis. J Periodontol 1997; 68: 313-319

10. Bjorn AL, Hjort P: Bone loss of furcated mandibular molars. A longitudinal study. J. Clin. Periodontol. 9:402-408, 1982.

11. Tal H: Relationship between the depth of furcal defects and alveolar bone loss. J Periodontol 53: 631-634, 1982.

12. Mealey BL, Neubauer MF, Butzin CA, Waldrop TC. Use of furcal bone sounding to improve accuracy of furcation diagnosis. J Periodontol 1994;65:649-657

13. Wang HL, Burgett FG, Shyr Y. The relationship between restoration and furcation involvement on molar teeth. J Periodontol 1993;64:302-305.

14. Joseph I, Varma BR, Mahalinga BK. Clinical significance of furcation anatomy of the maxillary first premolar: a biometric study on extracted teeth. J Periodontol 1996;67: 386-389.

15. Booker BW 3rd, Loughlin DM. A morphologic study of the mesial root surface of the adolescent maxillary first bicuspid. J Periodontol. 1985 Nov;56(11):666-70.

16. Howell MM, Cassingham RJ, Yukna RA. Relationship of maxillary molar root angulation and palatal vault height. J Periodontol. 57:25-28, 1986.

17. Muller H-P, Eger T. Furcation diagnosis. J Clin Periodontol 1999;26:485-498. (Review)

Describe Cervical Enamel Projections (CEPs), their classification and discuss their correlation with furcation involvements.

18. Masters DH, Hoskins S. Projections of cervical enamel in molar furcations. J Periodontol 35: 49-53, 1964.

19. Machtei EE, Wasenstein SM, Peretz B, Laufer D. The relationship between cervical enamel projection and class II furcation defects in humans. Quintessence Int. 1997;28:315-320.

20. Hou G-L, Tsai C-C. Cervical enamel projection and intermediate bifurcational ridge correlated with molar furcation involvements. J Periodontol 1997;68:687-693.

FURCATION MANAGEMENT

Discuss debridement, tunneling and root amputations/hemisections for furcation management.

Debridement

21. Bower RC: Furcation morphology relative to periodontal treatment - furcation entrance architecture. J. Periodontol. 50:23-27, 1979.

22. Bower RC, Thompson R.: Furcation morphology relative to periodontal treatment - furcation root surface anatomy. J. Periodontol. 50:366-374, 1979.

23. Otero-Cagide FJ, Long BA. Comparative in vitro effectiveness of closed root debridement with fine instruments on specific areas of mandibular first molar furcations. I. Root trunk and furcation entrance. J Periodontol 1997;68:1093-1097.

24. Otero-Cagide FJ, Long BA. Comparative in vitro effectiveness of closed root debridement with fine instruments on specific areas of mandibular first molar furcations. II. Fucation area. J Periodontol 1997;68:1098-1101.

Tunneling

25. Hellden LB, Elliot A, Steffensen B, et al. The prognosis of tunnel preparations in treatment of Class III furcations, a follow-up study. J. Periodontol. 60:182-187, 1989.

26. Rudiger SG. Mandibular and maxillary furcation tunnel preparations - literature review and a case report. J Clin Periodontol 2001;28:1-8.

Root Amputation/Hemisection

27. Carnevale, G., Pontoriero, R., Di Gebo, G: Long-term effects of root respective therapy in furcation - involved molars. A 10-year longitudinal study. J Clin Periodontol 25:209-214, 1998

28. Fugazzotto P., A comparison of the success of root resected molars and molar position implants in function in private practice: Results of up to 15 plus years. J Periodontol 2001 Aug; 72(8):1113-23

29. Kinsel, R., et al: The treatment dilemma of the furcated molar: Root resection versus single-tooth implant restoration. A Literature review. Int J Oral Maxillofac Impls 13:322-332, 1998.

Review

30. Cattabriga M, Pedrazzoli V, Wilson, Jr. TG. The conservative approach in the treatment of furcation lesions. Periodontol 2000 2000;22:133-153. (Review)

Is chemical root treatment of benefit in furcation therapy?

31. Parashis AO, Mitsis FJ. Clinical evaluation of the effect of tetracycline root preparation on guided tissue regeneration in the treatment of Class II furcation defects. J Periodontol 1993; 64:133-136.

How successful are the use of barrier for furcation tx?

Furca Treatment - Barriers - Non-resorbable

32. Pontoriero R, et al. Guided tissue regeneration in degree II furcation -involved mandibular molars. A clinical study. J. Clin. Periodontol 15:247-254, 1988.

33. Pontoriero R, Lindhe J. Guided tissue regeneration in the treatment of degree II furcations in maxillary molars. J Clin Periodontol 1995:22:756-763.

34. Mellonig JT, Seamons BC, Gray JL, Towle HJ. Clinical evaluation of guided tissue regeneration in the treatment of grade II molar furcation invasions.Int J Perio Rest Dent 1994;14:255-271

35. Pontoriero R, et al. Guided tissue regeneration in the treatment of furcation defects in mandibular molars. A clinical study of degree III involvements. J Clin Perio 16:170-4,1989.

36. Pontoriero R, Lindhe J.Guided tissue regeneration in the treatment of degree III furcation defects in maxillary molars.J Clin Periodontol. 1995 Oct;22(10):810-2.

Furca Treatment - Barriers - Absorbable

37. Yukna CN, Yukna RA: Multi-center evaluation of absorbable collagen membrane for guided tissue regeneration in human Grade II furcations. J Periodontol 1996; 67: 650-657.

38. Hugoson A, Ravald N, Johard G, Teiwik A, Gottlow J: Treatment of class II furcation involvements in humans with bioresorbable and nonresorbable guided tissue regeneration barriers. A randomized multi-center study. J Periodontol 1995, 66:624-634.

39. Rosen PS, Marks MH, Bowers GM. Regenerative therapy in the treatment of maxillary molar class II furcations: Case reports. Int J Perio Rest Dent 1997;17:517-527.

Discuss the relative long-term effectiveness of various treatment modalities in the management of furcation invasions.

40. Hamp SE, Nyman S, Lindhe J. Periodontal treatment of multirooted teeth. Results after 5 years. J Clin Periodontol. 1975; 2:126-135

41. Kalkwarf KL, Kaldahl WB, Patil KD: Evaluation of furcation region response to periodontal therapy. J. Periodontol. 59:794-804, 1988.

42. Muller H-P, Eger T: Managment of furcation-involved teeth. A retrospective analysis. J Periodontol 1995:22:911-917.

43. Evans GH, Yukna RA, Gardiner DL, Cambre KM. Frequency of furcation closure with regenerative periodontal therapy. J West Soc Perio (Perio Abstracts) 1996;44:101-109 (Review)

Discuss the etiology, incidence, and distribution of furcation invasions. Discuss the diagnosis and prognosis of furcation invasions by tooth type and compare to single rooted teeth. What role does root anatomy play in the etiology and management of furcation defects?

Waerhaug 1980                     ARTICLE

Purpose: To find out to what extent functional forces and subgingival plaque are involved in the etiology of the furcation involvement, and furthermore, whether or not marginal gingivitis and increased mobility reflect the degree of loss of periodontal attachment.

Materials and methods: 34 max and 12 mand molars with furcation were extracted due to advanced destruction of the periodontal tissues in the furcation area. 20 single roots from molar root resections were also included. All patients had been under periodontal treatment for a few months to several years (sub-g scaling and/or periodontal surgery), and had good OH. Prior to extractions the teeth where evaluated for PI, GI, and mobility. Premature contacts were identified. A landmark was made on the tooth surface at the gingival margin. Following extraction, the teeth were stained and examined under the stereomicroscope. The attachment loss was measured on the different surfaces of the roots with a translucent measuring device with 11 diverging lines.

Results: Gingivitis was found adjacent to 27% of the surfaces, supragingival plaque was present on 26% of them, on 39% of the surfaces there was sub-g, but not supra-g plaque. The average attachment loss was 47.3% on the outer surfaces and 62.8% on those facing the furcation. The average loss of attachment on the outer surfaces was 47.7% in the gingivitis group and 48.2% in the non-gingivitis.

Correlation between downgrowth of sub-g plaque and attachment loss

Distance from the front of the plaque mass (plaque front) to the attachment fibers: average distance 0.8mm on outer surface (0.2-2.4) and average distance 0.91mm on surfaces facing the furcation (0.2-4). 34 teeth exhibited normal mobility and the average loss of attachment was 41% on outer surface and 52% on surface facing furcation. 18 teeth were slightly mobile and average loss of attachment was 47% and 64% respectively. Premature contacts in CO were observed in 26% of teeth and most patients gave a positive answer to the question “has the teeth ever been tender or sore”. BOP and pain on probing were clearly less common in pockets without plaque.

DISC: Conditions below the gingival margin are extremely difficult to predict from clinical examination. Subgingival plaque is common even in the absence of supragingival plaque in patients who have started efficient supra-g plaque control after supra-g plaque has formed. Subgingival plaque may cause an undetectable submarginal gingivitis and lead to attachment loss and furcation involvement. The pathogenesis of attachment loss in furcations is associated with the down growth of subgingival plaque. Supragingival plaque control is ineffective in pockets greater than 3 mm (i.e. supragingival plaque control is effective to 2.5 mm). Surgical elimination of deep pockets is necessary (greater than 3 mm). Mobility and attachment loss do not support the assumption that functional forces are involved in the etiology of furcations. Mobility is the result of attachment loss, not the cause and appears late in the development of furcations.

Conclusion- Until now common solution to furcation problem has been extraction. With the knowledge about its etiology, it should be possible to prevent its development and to some extent treat established cases.

Ross 1980                     ARTICLE                                 incidence and distribution of furcation involvement

Purpose: To examine, compare, and evaluate furcation involvement in maxillary and mandibular molars.

Materials and methods:

• 615 molars of 72 patients (47 F, 25 M, 25-71 yrs old) with generalized chronic periodontitis were examined for age, sex, # of molars present, # of molars with furcation involvement (FI) detected radiographically and clinically, # of molars without FI, # of molars treated surgically.

• Inclusion criteria:

• At least one maxillary or mandibular molar with radiographic or clinical evidence of FI

• The molar w/ FI must be in contact with at least one opposing molar during vertical and horizontal mandibular movements.

• There must be at least 3 max molars w/ or w/o FI, a minimum of two in one quadrant and one in the contralateral quadrant.

• At least 3 mandibular molars w/ or w/o FI, a minimum of two in one quadrant and one in the contralateral quadrant.

• Treatment varied, but in no instance, was osseous surgery performed.

Results:

• FI is a common occurrence: 90% in the maxillary, 35% in the mandibular.

• FI 3X more frequently in the max molars.

• Teeth w/ FI functioned well for a long period of time (5-24 years).

• FI in max molars is detected more frequently by RAs, while in mandibular molars it is detected more frequently by clinical exam.

BL: Furcation involvement is a common occurrence and both radiographs and clinical exams should be performed to detect its presence. Prognosis and treatment should be based upon many factors, not just the presence of furcation. Furcation involvement should not condemn a tooth to an unfavorable prognosis.

Dunlap 1984                     ARTICLE

P: To determine the linear variation of Root Surface Area (RSA) in 1- mm increments from the CEJ to the apex for the mandibular 1^st molars

M&M: 20 extracted mandibular 1st molars. Coronal and apical sides of the sections were photographed and the circumference from the root was measured. Teeth with fused root sand obliterated CEJs due to caries or restorations were excluded.

R: The largest RSA and % total RSA values were located 4 to 7 mm apical to CEJ. 48.7% of the RSA was located in the coronal 6mm of total root length root (mean length 14.4mm). Root separation occurred 4 mm apical to CEJ with no teeth having a root trunk longer than 6mm. B and L root concavities were first present 0.7mm and 0.3mm apical to CEJ, respectively. The mean RSA of the mesial root was SSD greater than the distal root and both had greater RSA than the root trunks. Distal roots were always more conical in shape than mesial roots.70% of the teeth had an intermediate bifurcation ridge.

BL: Horizontal attachment loss of 5- 6mm affecting both B and L surfaces of mandibular 1^st molars can result in a through and through furcation involvement.

Gher 1984                     ARTICLE                               location of furcation entrances

Purpose: To determine the variation of root surface area in 1mm increments from the CEJ to the apex of max 1^st molar. Locations of furcation entrances, root separations and the roof of furcations were also determined.

Materials and methods: 20 maxillary molars were selected, only teeth with fused roots were excluded. After preparation teeth were sectioned in 1-mm increments and root surface area (RSA) for each section was determined.

Results/BL: Mean root length 13.6mm (10.5-16mm) and mean RSA 477mm².

17/20 teeth had the roots separated with 6mm from the CEJ.

% of RSA increased significantly in the furcation area from 7.53% to 8.8-10.1%.

11/20 teeth demonstrated dome or concavities in the roofs of the furcations and the other 9 teeth a trifurcation ridge.

Hou 1997                     ARTICLE                             furcation anatomy and dimensions

Purpose: To investigate the effect of vertical dimension & types of root trunks on the vertical & horizontal bone losses in molar furcations.

Materials and methods:

• Extracted teeth: 70 mx 1^st molars, 96 mx 2^nd molars, 103 mn 1^st molars, 97 mn 2^nd molars. Measurements of mx molars included vert height of buccal root trunk (BRT), mesial root trunk (MRT), & distal root trunk (DRT). Mn molars –BRT & LRT (lingual). Classified as:

• Type A –root trunk involving cervical 1/3 or less of root length;

• Type B-cervical 1/3 to ½;

• Type C-cervical 2/3 or greater.

Results:

BL: Longer root trunks are more common on 2^nd molars than 1^st molars

Ward 1999                     ARTICLE

P: To document mean, SD, & range of furcation depth & inter-root separation of 5 multi-rooted tooth types.

M&M: 273 multi-rooted teeth examined:Max 1^st & 2^nd M,1^st PM & Mand 1^st & 2^nd M. No restorations into the furcation, no fused roots. Furcation measured at level of the furc dome, then 3 & 5 mm apical to it. Inter-root separation measured 3 & 5 mm apical to the dome. Teeth were examined using telescopic lenses with 2.6x magnification.

R:

D: Furc depth ↓ in an apical direction, except for the buccal furcation of max molars, due to flaring of the palatal root. In regenerative healing, this means that as vertical entrance height ↑, the amt of bone ↓. Since root tapers in apical direction, root circumference ↓, decreasing the amt of PDL cells available to re-populate the wound. For max molar buccal furcation, the amt of bone ↑ w/ increasing vertical height, but the amt of PDL cells ↓, due to apical root tapering.

Inter-root separation increased from the dome to 3 then 5 mm except for the lingual of mand 2^nd M, due to convergence b/w the mandibular roots in this area (pincher-like curvature)

BL: Height, width & depth of furcation differ for each furcation. As such, optimal conditions for GTR are different for every furcation. Additional research needed to find critical furcation dimensions for GTR.

Paolantonio 1998                      ARTICLE

P: Morphometric and morphologic analysis of maxillary and mandibular first and second molars using three different techniques.

M&M: 207 maxillary molars (105 first and 102 second molars) and 207 mandibular molars (110 first and 97 second molars) were measured; root length, radicular trunk length (RTL), mesiodistal(MDD) and buccolingual diameters (BLD) at the CEJ, inter-radicular angle (IRA**) width, and furcal roof area (FRA) were recorded.

Morphologic examination was carried out by stereo microscopy, light microscopy of undecalcified sections, and scanning electron microscopy.

R: Morphometric:

• IRA width decrease from 1M to 2M in both arches, more pronounced in maxilla.

• FRA is wider in 1M.

• 1M longer roots & shorter radicular trunks than 2M.

• MDD & BLD are greater in 1M.

• + correlation FRA/IRA for each molar.

• + correlation BLD/IRA in both max M.

• inverse correlation IRA/RTL in max 1M.

• NSS correlations for the other measurement.

Morphologic:

• Width of furca entrance.

• Long RT .

• Concavities internal of roots in mandibular M and M-B root of maxillary M.

• Furca roof, narrow and irregular shape dimples, holes & crevices.

• Furca canal orifices coming out into larger depressions.

CL: This study showed the complexity of the furcation area with a large number of anatomic irregularities and plaque-retentive structures that could hamper adequate cleaning during periodontal treatment.
IRA**: this measure was assessed by drawing a line in the center of the cervical third of each root and measure the value of the angle between each pair of lines with a goniometer.

Ross and Evanchik 1981                     ARTICLE                    incidence and distribution of root fusion

P: to report the incidence and distribution of root fusion in molars.

M&M: Radiographic examination of 1340 molars from 170 patients. Any molar that had one root or whose roots were fused apical to the usual furcal position was considered a molar with fused roots.

R: Frequency of molar fusion

Overall 29% of all molars were fused and 71% non-fused. Fusion occurs bilaterally with equal distribution. Females have more root fusion than males. Root fusion was more common in the maxilla (35%) than the mandible (24%). Furcation can be an important factor in determining the prognosis of a tooth. Usually these roots are shorter (contribute to an unfavorable crow-root ratio) and more likely to become mobile.

BL: 29% of all molars had fused roots. Root fusion was more common in the maxilla and more from post to ant (3^rd M > 2^nd M > 1^st M)

Hou 1997                     ARTICLE

P:  To examine the relationship between molar root fusions and localized periodontal disease.

M&M:  143 individuals (1109 molars) aged 23-68 years were examined for molar root fusion at diseased and healthy sites by periapical radiographs and clinical probing.  PD, CAL, GI, and Pl were measured. The molars with root fusions, intact marginal alveolar crest, and CAL ≤ 5mm was considered healthy.

R:  The prevalence of molar root fusions in males was 15.2% vs. 32.2% in females.  Max 2^nd molars (51.8%), mand 2^nd molars (32.3%), max 1^st molars (5.7%), and mand 1^st molars (0%).  Prevalence of root fusion in max molars is 28.7% and mand molars is 16.7%.  SSD was observed in GI, CAL, PD and Pl between diseased and healthy sites.  97.5% had bilateral symmetry of fused roots.  A majority of the diseased molars with root fusion exhibited deeper developmental grooves than the healthy molars.

BL:  Females tend to have a higher rate of molar root fusion.  Deep developmental grooves and the less resistance to heavy occlusal loads and/or torque forces enhance the possibility of localized periodontitis at molars with root fusion

Bjorn 1982                     ARTICLE

Purpose: To obtain information on the prevalence of interradicular bone destruction in mandibular molars as well as the fate of involved molars in a population not included in any periodontal treatment program.

Materials and methods: 221 staff members of an industrial company in Sweden were utilized. Panoramic radiographs and bite-wings were examined. Furc involvement was diagnosed when there was visible interradicular bone destruction.

No clinical examination was performed. The amount of radiographic bone loss was estimated using a plastic ruler and classified in 5 categories:

• 0 no bone loss

• 1 0-25%

• 2 25-50%

• 3 50-75%

• 4 more than 75%
  The total observation period was 13 years.

Results: The mean number of mand. molars/patient was 3.5 in 1965 and 3.3 13 years later. 15 individuals had lost all the remaining molars. The frequency of molars with interrradicular periodontitis increased from 18% to 32% during the study period.

9.5% of the furcated molars observed at the first examination was lost, 2.5% because of periodontal disease.

2^nd and 3^rd molars exhibited increased bone loss when compared to the 1^st molars. The severity of bone loss increased with age.

Conclusion: Furcation involvement has evidently not played any dominant part in the loss of mandibular molars during this 13-year observation period. This does not imply that furc. involvement may not in the long rung jeopardize the retention of a tooth.

Tal 1982                     ARTICLE

Purpose: To determine whether there is any relationship between the depths of furcal defects and the amount of alveolar bone loss on the buccal and lingual aspects of 1^st and 2^nd molars in dry mandibles

Materials and methods:

• 100 dry mandibles of South African tribe members of known sex, tribe and age (20 in each decade, between third and seventh decade; since no dental treatment on these skullsassume no OH education). The depths of furcal defects and the distances between the CEJ and alveolar bone crest were measured on 245 lingual and 235 buccal surfaces of 246 1^st and 2^nd molars; Class III FI excluded.

Results:

• High correlation between depth of furcal defects and distance between the CEJ and alveolar crest, w/ higher correlation for first molars than for second molars.

• For the same degree of vertical bone loss, buccal furcation defects are deeper than the lingual, and buccal furcation defects on 1^st Molars are deeper than those on 2^nd Molars.

BL: Bone loss is greater on the facial than the lingual and is greater in 1st molars. Also, when 5-6 mm probing depths are present, one should suspect a class III FI. The elimination of furcation disease is essential to the success of periodontal therapy. Detection of furcation involvement is an essential part of any complete oral examination.

Mealey 1994                     ARTICLE

P: To compare vertical and horizontal measurements of furcation invasions taken by probing prior to anesthesia, by bone sounding following anesthesia and by direct assessment after surgery debridement.

M&M: 67 patients (42M, 25F), age 30-76 y.o. 276 furcations with vertical & horizontal depth were assessed at 3 separate time points. For the vertical dimension pre-anesthesia, measurements taken with a straight probe from FGM-flute, & then probe advanced until resistance noted. Horizontal dimension was taken with a Nabers probe from FGM-flute and then until resistance felt. After anesthesia, bone sounding performed. Direct measurements were taken during surgery (vertical: straight UNC probe from initial fluting of furcation to bony defect; horizontal: Nabers probe from flute to depth of bony defect into furcation). None of the subjects had 3^rd molars present.

R: Mean vertical (1.8mm) and horizontal (2.16mm) furcation depths prior anesthesia were sig less than surgical measurements (2.79mm & 3.65mm respect). Surgical vertical depth was exactly the same as pre-anesthesia probings in 42% of the furcations, within 1 mm in 72% and within 2 mm in 83%. Surgical horizontal depth was equal to pre anesthesia probing in 47% of furcation, within 1 mm in 68%, and within 2 mm in 77% of cases. Use of post-anesthesia sounding improved agreement in vertical measurements ranging from 59.5% to 93%. Sounding improved the agreement of horizontal measurements from 64%-88%. Vertical sounding provided the greatest improvement in diagnostic accuracy for the facial furcations of mandibular second molars. Horizontal sounding had the greatest beneficial effect for the distal furcation of maxillary second molars. The use of sounding sig improved the accuracy of the measurements, however, there was still a small percentage of horizontal measurements that were significantly underestimated.

BL: Sounding reduced the degree of underestimation in all furcation types.

Wang 1993                    ARTICLE                         the impact of restorative dentistry on furcation involvement

Purpose: To study the impact of crown (CR) or proximal restoration (RE) on furcation involvement (FI) in molar teeth.

Materials and methods: 134 maintenance patients who had molars with and without FI and restorations were selected from University of Michigan patient pool. The majority of the patients had restorations for at least 5 years prior to the study. Clinical evaluation included assessment for CR, RE, endodontic treatment, FI, mobility more than 0.5mm in bucco-lingual direction, AL and PD for six sites/tooth. Data were analyzed and statistical analysis was performed.

Results:

• Molars with CR or RE had a significantly higher presence of FI than molars without restorations.

• Relationship between restoration status of the molars and mobility was not significant while that of endodontic Tx was significant but with small sample size.

• More probing AL was measured in molars with RE< FI and mobility than in molars without the occurrences. More AL was found in molars RE and CR especially in the maxilla.

Conclusions:

• Molars with CR or RE had a higher prevalence of FI and greater AL than non-restored molars.

• The difference in AL between restored and non-restored molars occurred mostly in the maxillary arch.

• Mobility was found to be a significant factor for AL but not FI.

Joseph 1996                     ARTICLE

P: to determine the frequency of bifurcation, and to explore the anatomy of max 1^st PMs.

M&M: examined 100 extracted max 1^st PMs. Teeth w/ caries, restorations, or damage were excluded.

R:

• Only 37% of the examined teeth had bifurcated roots, the remaining had fused roots 63%.

• Proximity of the furcation to CEJ- 35% apical third, 38% at the middle third, 27% at the cervical third.

• The mean furcation width was 0.7 mm, which is less than the blade width of Gracy curette.

• Concavities were found on the M and D of the root trunk in all 100 teeth examined

• Furcal concavity was also found in 62% of the teeth with bifurcated roots

Disc: According to Corn et al. (1980), as a rule, the prognosis for maxillary first premolar teeth with osseous defects in the inter-radicular area is poor.

BL: frequency of bifurcation in max first premolars is 37%.

Booker 1985                     ARTICLE

P: To study the morphology of the mesial root surface of the maxillary 1st premolar (PM) and establish incidence and frequency of furcation, along with baseline measurements pertaining to that aspect of the root.

M+M: 25 single rooted and 25 two-rooted adolescent maxillary 1st PMs were extracted then sectioned in 2-mm thick sections apical to the CEJ. Under dissecting microscope, the mesial concavity depth and the cementum and dentin thickness were measured in the sections.

R:

• The mean distance from the mesial CEJ to the furcation of the maxillary first PM= 7.91mm

• 100% of PMs had M concavity on root.

• The single-rooted PMs have a concavity 0.35 mm deep M concavity at the CEJ and a concavity of 0.59 mm deep 7 mm apically to the CEJ (decreased apically past that point).

• Two-rooted PMs had a .44 mm deep M concavity at the CEJ and this increased in depth until bicuspid furcated.

• 100% of two-rooted PM had “developmental depressions” in the furcal aspect of the buccal root at the 9.4 mm level.

• The cementum thickness increase from the CEJ-apically.

• Most PMs also have a shallow distal concavity.

BL: Any attachment loss around the max 1st PM involves surfaces which are most likely concave. These concave surfaces make both plaque removal and periodontal treatment difficult. Removal of M concavity is contraindicated due to potential pulp exposure.

Howell 1986                     ARTICLE

Purpose: to investigate the relationship b/w max molar root angulation (MMRA) and palatal vault height (PVH), hypothesis being that a high vault will be accompanied by a more vertical palatal root angle and would therefore be a more favorable situation to support vertically directed occlusal forces.

Material and methods:

• 33 Human cadaveric maxilla were sectioned B-L through each tooth root to the P midline and photographed.

• Root angles and PVH were measured on the photos in relation to a reference line connecting B and P CEJ. PVHs were classified as low, medium, or high according to the perpendicular distance from the midpalatal suture to the reference line.

• Root angles were subtended by a line following the length of pulp canals and perpendicular to the CEJ reference.

Results:

• Analysis by Spearman's Rank Correlation Coefficient demonstrated a weak and non-significant relationship b/w PVH and the MMRA.

• The mean PVH was 18.4 mm (Low < 14.3, high  22.3 mm).

• 1st molar root angulations varied from 11.6 to 16.0˚.

• The P root of 1st molars showed the greatest mean deviation from vertical, and MB mean root angle was closest to vertical.

• Roots of the 2nd molar showed a more consistent mean tilt (about 10˚) 1999 (review)

P: To review current info on impact of proper diagnosis of furcation lesions

Morphology: Progression of periodontitis is largely affected by the morphology of the root. Carlsen described the concept of the root complex as formed by root cones, root grooves, interradicular projections, furcation, and root trunk. He reports more variability as you move posteriorly.

Maxillary molars: Buccal furcation entrance is narrower than mesial or distal (Bower). The root trunk is >3mm. Average root trunk 3.5-3.6 Mesial, 3.5-4.2 B and 4.1-4.8 D. Distal furc entrance is more apical, and high degree of divergence bw B & P roots. The MB root is standing mainly vertically, the DB and P root are inclined to a varying degree. The MB root of 1^st M is composed of mainly 3 cones, & the others roots of 2. (Carlsen). Root concavities within furcation are mostly on MB root (w/ avg of 0.35mm) (Roussa), with root concavities on all surfaces above the furca (0.5 D-0.7mm B). Furcation roofs mean concavities 1.2mm D and 2.7mm M. Root fusions are rare on 1^st molars, but more common on 2^nd & 3^rd molar (Hou & Tsai). CEPs more freq at B furc of 1^st M (Moskow & Canut).

Mandibular molars: Each root resembles an hour-glass in cross-section, mostly composed of 2 cones. The relative height of root trunk increases as you go posteriorly (Carlsen). Concavities on both outer and furcal sides of the root, specially marked on M root (Bower). Within the furc, concavity at M root 0.5mm and at distal root 0.3mm. The lingual furcation entrance is located more apically. Entrances have similar widths. Outside the furcation, the root is usually concave up to the CEJ, about 1mm. Deep furcal roofs of >3mm on average, increase as move posteriorly (Roussa). CEPs more common in mand molars, especially Asian descendent (Hou & Tsai).

Other teeth: M root of 1^st PM has concavity starting at CEJ and moves apical to furca. Distance between CEJ-furca is ~8mm (Booker). Enamel pearls less frequent. Max central and laterals contain mesial-cervical groove and can advance to apex.

Clinical Diagnosis: Highly variable. Reproducibility of the horizontal measurements was better at sites with a vertical dimension of more 1mm to 2mm. Bone sounding proved to be more accurate (Renvert; Ursel).

Classifications: Furcation involvments are usually over-estimated, except for Class III. Glickman’s, Hamp classifications described.

Radiographic analysis: Are only reliable tool to measure bone loss in relation to tooth. The actual severity of advanced furcal involvement may be underestimatedby PA’s or BW, whereas an initial involvement may be overestimated by PAN’s (Topoll).

Intraoperative measurements: In a study by Pontoriero, where only 1/42 were clin dx’d as Class III, all turned out to be T&T. The critical area for regen reclosure of furc was ~3mm².

Describe Cervical Enamel Projections (CEPs), their classification and discuss their correlation with furcation involvements.

Masters 1964                    ARTICLE

P: To examine cervical enamel projections in molar furcations

M&M: 474 extracted maxillary and mandibular molar teeth were examined for enamel projections in the furcations. A grading scale was assigned to the enamel projections. 

• Grade I: a distinct change in the CEJ attitude with enamel projecting toward the bifurcation. 

• Grade II: the enamel projection approaching the furcation, but not actually making contact with it.

• Grade III: enamel projection extending into the furcation proper.

R: Of the 304 mandibular molars examined 28.6% had enamel projections. Projection was more often found on the facial surface. Grade III projections were seen 4.3% of the time. Of the 170 maxillary molars, enamel projections were seen 17% of the time with Grade III projections 4.8% of the time.

BL: Enamel projections are responsible for approximately 90% of isolated bifurcation involvements

Machtei 1997                     NO ARTICLE

Purpose: To examine the frequency of CEP in mandibular molars with class II furcation defects and to determine its effect on the success of GTR in these defects.

Materials and methods: Healthy patients and teeth with no PA involvement of pathology were selected. Teeth had Class II furc. Involvement unilateral or bilateral. PD, vertical (PAL-v) and horizontal (PAL-h) probing attachment level were recorded at baseline and every 3 months thereafter during a 1-year period using a Florida probe.

Teeth with PD 5m or more and PAL-h greater than 3mm after initial Tx were subjected to surgical periodontal therapy. During Sx frucation area was exposed and examined for CEP. Meticulous SRP, enameloplasty and GTR with e-PTFE membranes was performed. Pts were covered with antibiotics for 2 weeks, NSAIDs for one week and instructed to rinse with Chx. Membranes were removed at 4-6 weeks. Pts were recalled for prophy every 2 weeks during the first 12 weeks and monthly for the remaining 9 monts.

CEP observed during surgery were classified according to Masters and Hoskins.

Results:

• Mean PD reduction was 2.61mm (1.64mm-7.21mm), mean gains in PAL-v 0.77mm and PAL-h 2.47mm. Prevalence of CEP: Grade 0: 17.9%, Grade I:23.8%, Grade II: 38.4% and Grade III: 23.6%.

• Patients with CEPs demonstrated higher mean PDs, PAL-h and PAL-v at baseline than those without CEP. Similar PD reduction was observed between teeth with and without CEPs. The residual PD was higher for teeth with CEP but this difference was NSSD.

• When each Group of CEP (Grade 0, 1, 2, 3) was analyzed and compare there was SSD in baseline PD only between Grade 0 and Grade 1.

• SSD in post-op PD reduction between Grade II and Grade III (higher reduction in Grade III).

• In PAL-v changes, Group I showed a 0.6mm reduction and Group 3 1.4mm.

• The gain in PAL-h was smaller in Group 1 than in Groups 2 and 3.

Conclusion: CEPs might be considered a secondary etiologic factor in periodontal breakdown and attachment loss. When the CEP was removed in conjunction with a regenerative procedure, healing was better than in similar teeth without CEP.

Although in greater risk for breakdown, mandibular teeth with CEP should be considered good candidates for GTR.

Hou 1997                     ARTICLE

Purpose: To investigate the possible relationship b/w the presence of molar cervical enamel projections (CEP) combined with intermediate bifurcational ridge (IBR) and localized furcation involvements; the prevalence, distribution, and degree of CEPs and IBRs in patients with furcation involvements of molars; and the periodontal status of the tissues adjacent to the furcal areas of molars w/ and w/o CEPs and IBRs.

Materials and methods:

• 87 hopeless mandibular molars (51 1^st M and 31 2^nd M) w/ class II FI and alveolar bone loss >70%, requiring extraction for perio therapy, were collected over 5yrs.

• Clinical records with PD, GI, PI, and distance from CEJ to furcation were made before extraction. PA radiographs taken. Measurements of CAL were taken by methylene blue staining after molar extraction. CEP and IBR were evaluated microscopically.

Results:

• Furcation involvement: more frequent in mand 1^st molars (73.5% F, 58.5 % M) than 2^nd molars (26.5%F, 41.5%M).

• CEP +IBR prevalence 63.2% (55/87): Mand 1^st 67.9%, Mand 2^nd 54.8%.

• CEP alone prevalence 21.8%.

• IBR alone was 2.3%.

• Molars with neither 12.6% (11/87).

• Grade III furcation had CEPs more common (69%) than grades II (9.2%) and grade I (6.9%)

• Higher grades of CEP and IBR’s are associated with worse perio parameters: FI, PD, CAL, PI, GI.

BL: CEP+IBR are present in a high percentage of mandibular molars. CEP’s predispose molars to more rapid progression of pocket formation. Furcation involvement becomes more likely because a close proximity of CEP’s to the furcation and irregularity of IBRs on the furcation root allows for retention of microbial plaque.

Discuss debridement, tunneling and root amputations/hemisections for furcation management.

Debridement

Bower 1979                     ARTICLE
P:  To investigate whether furcation morphology may influence instrumentation using curettes in max and mand first molars.

M&M:  114 max and 103 mand 1st molars from a collection of extracted teeth were studied. The teeth were cleaned and measurements of M-D width, furcation entrance diameter, correlation between M-D width and furcation diameter, and width of the curette blade face were taken. The furcations were measured using machined metal test gauges ranging in size from 0.5-2 mm (0.25mm increments) under a dissecting microscope at 6.3x magnification. The curette blades were measured using a Vernier caliper and recorded to the nearest twentieth of a millimeter. All instruments were unused and had not been sharpened.

R:  81% of all furcas had an entrance diameter of  ≤1 mm, and 58% were ≤ 0.75 mm. In 85% of the max 1 molars the buccal furcation entrance was ≤0.75mm, whereas this was the case in 49% of the mesiopalatal and 54% of distopalatal. The M-D width did not correlate with the furcation diameter. In all cases, the blade face was within the range of 0.75 mm to 1.10 mm, regardless of the type and manufacturer of the instrument. However, Gracey curettes were narrower than Columbia curettes.

D: The lack of correlation between furca entrance diameter & M-D width at the CEJ in the 1st molar teeth indicate that large teeth do not necessarily have a large furca entrance diameter.

BL:  Root preparation is very important, but it is very unlikely that commonly used curettes alone will allow for adequate preparation of this area. In 58% of furcas, the diameter of the entrance was smaller than the curette. The B furca in max & mand 1st molar is smaller than the others.

Bower-2 1979                     ARTICLE

Purpose: To investigate which morphologic features of maxillary and mandibular 1^st molars might influence plaque control and root preparation.

Materials and methods:

• 114 maxillary and 103 mandibular teeth were used and sectioned at right angles to the long axis at a level 2mm apical to the most apical root division.

• Cut tooth surfaces were examined using a dissecting microscope and calibrated measurements were done.

• For the max molars the concavity of the furcal aspect of the roots was measured and the angle between the cut edges of the furcal aspects of the buccal roots.

• For mandibular teeth concavity of furcal aspect of the roots and minimum and maximum mesiodistal dimension of the furcation was measured.
   

In the 2^nd part of the study 92 of the max and 85 mand teeth were used again and examined with the same dissecting microscope and the concavity of root surface, depth of concavity of dentinocemental junction of furcal aspect and cementum thickness between these two concavities were measured.

Results/BL:

• Concavity of furcal aspects of max molars: Concave in 93% of mesiobuccal roots, 31% of distobuccal and 17% of palatal roots. Mean depth 0.3mm in mesiobuccal and 0.1mm in the other two.

• Divergence of furcal aspects of buccal roots of max 1^st molars: 96% divergent towards the palate and 3% were considered parallel.

• Concavity of furcal aspects of mand 1^st molars: 100% of mesial roots (0.7mm depth) and 99% of distal roots (0.5mm depth).

• Minimum distance between the buccal half of furcation in the mandibular teeth was 2.4mm and 2.5mm on the lingual at the level of section. In the central region it was 3.6mm.

• Little indication of internal furcation morphology can be gained from mesiodistal tooth size.

• Cementum distribution was not uniform. The mean net effect of cementum on dentinocemental junction concavity was found to be higher on max mesiobuccal root and lower on the palatal teeth.

Otero-Cagide 1997                     ARTICLE

Purpose: to compare curettes with a small blade (2mm long x 1mm wide) to slim US (0.5mm in diameter at pointed tip) inserts in removing artificial deposits from the root trunk & furcation entrance of mandibular 1st molars using an in vitro model simulating a closed SRP.

Materials and methods:

• 00 artificial molars (50 right, 50 left) with black paint in furcation and on root trunk mounted in cast to simulate a clinical situation.

• Class II or III furcations with 5mm PD simulated. Half treated with curettes & half with US by 1 operator. Each tooth treated for 4 min.

• The teeth were then analyzed by computerized imaging for remaining material.

Results:

98 teeth analyzed (2 damaged during exp). Complete removal of all deposits was not attained.

Discussion:

Accessibility was not a limitation for either type of instruments, & the higher debridement achieved by the curette might have been the result of a better contact of the instrument with root surface.

The effectiveness of the curettes may not apply to narrower furcations (1mm width in this study).

BL: the tested curettes were more effective at removing the artificial deposits than the US tips. Also, the root trunks were debrided more effectively than the furcation entrances.

Otero-Cagide F and Long B 1997                     ARTICLE

P: To demonstrate the extent of deposits removed from within the furcation area of mandibular 1^st molar following the use of curettes with a modified blade and slim (0.5mm) US inserts in an in vitro model simulating a closed root debridement approach to furcation treatment.

M&M: Furcation areas of 100 artificial mandibular 1^st molars were uniformly coated with black model paint. The molars were fixed into a custom acrylic model, maintained in a firm position with modified occlusal splints, and the roots covered with a heavy rubber dam. The model was set in a mannequin and mounted on a dental chair recreating a clinical situation. Fifty molars (25 right, 25 left) were instrumented with the experimental curettes and 50 with the US inserts. An experienced dental hygienist completed all the instrumentation, spending 4 min on each molar. The molars were sectioned buccolingually from the crown apically to separate the roots, and areas in the internal surface of mesial and distal roots were analyzed to determine the % of deposits remaining using a computerized imaging routine system.

R: The curettes produced furcation root surfaces with significantly less percentage of residual deposits than the US

BL: This study indicates the potential value of small bladed curettes in debriding involved furcations during initial therapy and supportive periodontal therapy. The current findings should be confirmed in a clinical study.

Tunneling

Hellden 1989                     ARTICLE

P: To retrospectively evaluate the long-term prognosis after tunnel preparations in Treatment of Class III Furcation (teeth w/through-and-through furcation involvement)

M&M: 102 pts (149 teeth) were evaluated for 10-107 months (mean 37.5) after the tunneling procedure.

Max PMs and 1st, 2nd and 3rd max/mand molars were treated. Prior to treatment, but not related to perio disease, some teeth required RCT (47) and 33 were abutments for fixed bridge. After treatment, pts were followed q 3-6 mos for 2 yrs and then were returned to their referring dentist for continued care.

R: 10 teeth were extracted and 7 teeth had been hemisected or root resected. According to the referring dentist 6 of these teeth were extracted and 6 were hemi or root resected due to caries. 132 tunnel preps were available for evaluation. Among these, 11 developed incipient root caries and 12 established carious lesions (17% caries). Most PD’s remained below 3 mm, 11-36% were from 4-6 mm, and <4% were deeper than 6 mm.

BOP at 1 or more sites was observed in 67% of the examined teeth. 3.5% showed marked mobility (2 or 3). The majority of the teeth were not associated w/discomfort (92%), gingival bleeding (72%), or sensitivity to cold/hot (95%). Most pts used an Interproximal brush for the tunnel areas.

BL: Tunnel preps have a considerably better prognosis (75% of the teeth were caries free and in function) than previously reported and should be considered an additional treatment modality.

Rudiger SG 2001                     ARTICLE
P: To review the literature concerning the tunnel preparation procedure as a treatment alternative for furcation-involved molars: indications, post-op risks and long-term outcomes.

D: Furcation tunnel preparation, i.e., the creation of access for plaque control between periodontally diseased roots appears to have a similar success rate as root resective therapy.

• Indications: Grade II or III w/deep horizontal involvement. A short root trunk (<1/3 total root length) and a wide furcation entrance diameter are necessary. Mand 1^st molars have the highest percentage of furcations meeting these criteria.

• Pulp: Although accessory canals in the furcation area are frequent findings (23%-60%), endo complications have not been reported to be major complications after tunnel preparation.

• Caries risk: Caries common complication after any root exposure (including APF). It is reported as a major complication in most studies, but does not always lead to tooth loss. Need to compare tooth loss after tunneling to tooth loss after other therapies.

Case Report: 43 yr old male w/ mand & max molars having furcation involvement (deep PD and BOP). 1^st mand molar tunneled, 2^nd molars were extracted and max 1^st molars double tunneled. Occlusal adjustment. Pt demonstrated excellent plaque control before and after surgical involvement periodontal health could be established and maintained at both single and double tunnels over a period of 2 yrs w/continued monitoring and SPT.

BL: Tunneling is a treatment alternative worth to consider, even for maxillary molars.

Root Amputation/Hemisection

Carnevale 1998                     ARTICLE

Purpose: The present investigation was designed to evaluate the long-term effect of root-resective therapy in the treatment of furcation-involved molars.

M&M: The patient sample included 72 patients, 21-62 years of age, who presented periodontal lesions in the posteriors segments of the mouth including maxillary and mandibular furcation involvement teeth of various degrees (Class II and III). During the surgical procedure, the furcation-involved teeth were subjected to root-resective therapy in conjunction with osseous recontouring and apically positioned flaps (test sites). A surgical procedure identical to the test procedure was performed in the non-furcation-involved teeth (control sites) with the exception of the root resection. At the completion of the active phase of treatment, 175 test and 175 control sites were available for the study. After a period of 6 months of healing and plaque control supervision following surgical procedures, the patients were recalled for a baseline examination. They were then enrolled in a maintenance program including professional tooth cleaning every 26 months. The patients were re-examined 3, 5 and 10 years post-operatively.

Results: In test group, total of 12 teeth were extracted due to endo failure, root carries and perio disease recurrence and root fracture. In the control group, 2 teeth extracted for perio disease.  63% PD was more than 5 mm for test group and 25% for control group. After 5 years, 12% sites with 4-5 mm PD was present in test group and 3% for control group. After 10 years, 23% test site and 6% control site had 4-5 mm PD. The results of the assessments demonstrated that the survival rate, during the 10-year period of observation, reached 93% at test and 99% at control sites. The positive treatment outcome at the root-resected, furcation-involved teeth as well as at non-furcation-involved teeth was probably the consequence of the reestablishment of a tissue morphology favorable for oral hygiene and careful plaque control by the patients.

Fugazzotto 2001                     ARTICLE

Purpose: To examine the success and failure rates of root resective therapy and molar implant placement and restoration in function over time.

Materials and methods: Retrospective analysis of treatment result in one practice was carried out by examining active and inactive patient charts. Patients had received the above treatments and were still active patients in the practice, being seen in regular intervals for maintenance visits or had been followed on a regular maintenance schedule for at least 5 years. A complete examination of oral hard and soft tissues was carried out for each patient. Medical histories were reviewed. No patients progressed to the surgical phase of therapy unless they were able to demonstrate adequate plaque control measures (plaque score 10% or less).

• Patients were excluded from the study if they were heavy smokers (more than 10 cigarettes/day) or if Sx was contraindicated because of their medical status.

• After root resection and endodontic Tx, teeth were restored with single crowns or used as abutments for fixed prostheses.

• When implants were placed they were restored either with single crowns, or implant supported fixed splint or implant-tooth supported fixed splint. In the maxilla some implants were placed with concomitant sinus augmentation procedure. Different implant systems were used (Nobel, Implant Innovations, Straumann, CoreVent).

• Definition of success: Root resected molars: no PD more than 4mm, no BOP at more than one maintenance visit, no exudation, no recurrent caries or root fracture.

• Implants: Albrektsson’s criteria were used ( stability of crestal bone levels surrounding the implants, lack of soft tissue inflammation, lack of edema, lack of exudate etc).

Results:

• 701 molars resected in 628 patients with 96.8% successful in function for up to 15 years. (Range from 91.3% for max. right second molars to 97.8% for mand. right second molars when analyzed per tooth type, and 75% for distal roots of mand. molars to 100% for mesio- or disto-buccal roots of max. molars).

• 1,472 implants were placed in 1,102 patients with an absolute success rate of 97% (range from 84% for mand. 2nd molars to 98.4% for mand 1^st molars).

• Both treatment showed higher failure rates when used as distal abutments or were associated with untreated parafunction.

Conclusion: Both treatments demonstrated high degree of success. Careful treatment planning is required to select the appropriate treatment modality.

Kinsel 1998                     ARTICLE

Purpose: Literature review discussing treatment of the furcated molar.

Discusion: For furcated molar teeth, accepted treatment modalities include chemotherapeutic maintenance, root planing, open flap debridement, modified widman flap, bone grafting with and without guided tissue regeneration, and osseous resection with and without root removal. Root resection and single molar implant placement are relatively newer treatment options, and were discussed in this review.

Indications for root resection include:

• Severe vertical bone loss involving only one root of a mandibular molar.

• Bone loss involving one or two buccal roots, or a palatal root of a maxillary molar, resulting in furcal invasion that is inaccessible for plaque removal procedures.

• Exposed roots that are too close together as a result of interproximal bone resorption, to the extent that maintenance of class I or II interproximal invasion is impossible.

• Furcations exposed through caries or bone loss that cannot be properly restored and would preclude adequate maintenance.

• Abutments or piers within a fixed partial denture combined with a negative prognosis because of periodontal disease.

• Multirooted teeth combined with an individual root fracture.

• Roots of nonvital teeth that cannot be treated by conventional RCT or retrograde techniques because of the presence of lateral canals, partial calcifications, dilacerations, pulp stones, perforations, or broken instruments

• Molar teeth are at greater risk from periodontal disease.

• Furcated molars are generally difficult to maintain long-term, having a propensity for early loss because of periodontal disease.

• Root resection therapy shows poor long-term results unless a high level of expertise is available in all applicable disciplines: periodontal, endodontic, and restorative.

• The predictability of successful osseointegration with long-term stability is well supported by the literature.

• Single molar-tooth implant restorations show promising short-term results, although the number of applicable reports is currently limited.

BL: Success of dental implants may indicate that the surgical and restorative procedures are less difficult than management of molar functions w/ root resective therapy.

Review

Cattabriga 2000                     ARTICLE

P: A review on the conservative approach in the treatment of furcation lesions.

D: The conservative approach defined in this article comprises sx and non-sx tx employed to debride the furcation area excluding regeneration and root separation procedures.

-Longitudinal prospective and retrospective studies showed that in molars with furcation involvement, the results are not as satisfactory as those obtained for single-rooted teeth or nonfurcated molars. Nevertheless, these studies showed acceptable long-term functional survival rate for furcated molars, indicating that the presence of furcation involvement is not per se a reason for assigning a questionable to hopeless prognosis to these teeth.

-Numbers and % of spirochetes, total anaerobic CFUs and numbers of P.g. were always higher in furcations than in non-molar sites (Loos 1988).

-The reduced rate of success experienced with the conservative approach in the tx of furcation involvement seems to result from the incomplete removal of hard and soft debris present in the interradicular area owing to the peculiar anatomy of the furcation space (CEPs, bifurcation ridges, convexities, concavities and furcation entrance dimension).

-Significantly more residual calculus was left in furcations 2.3mm wide after debridement with curettes than with ultrasonic scalers (Matia 1986). Rotary diamond burs have also been used to clean narrow furcations.

- Although SRP combined with flap sx is more effective at removing calculus the clnical evaluations do not indicate a dramatic difference between sx and non-sx tx irrespective of the degree of furcation involvement. Rather, closed SRP is more effective at preserving the existing AL, together with producing a more expeditious bone remineralization, although these phenomena are accompanied by a lesser reduction in PD. The equivalence in clinical efficacy between closed and open procedures may be attributed to the procedure, operator variables, compliance with professional recommendations, the initial risk of the pt, or, most likely, a combination of these factors.

-The results from the literature to not lend clear acceptance to the implementation of adjunctive local drug delivery in furcations, regardless of the severity. Short-term results in reduction of PD and BOP reported by Tonetti are promising, but there does not appear to by any long-term advantages yet proven.

-Tunneling: a very limited number of studies have been performed on the tunneling preparation, with differing results. The study by Hellden, which enrolled a considerable number of pts, demonstrated promising results, although mean observation time was limited. More studies are needed. Root caries may be an issue.

-Root amputation: very little information is available on root amputation and odontoplasty. Root amputation has not been extensively used in clinical long-term trials, so caution must be exercised when interpreting the results.

-Studies on regeneration have shown unpredictability of complete closure of furcation involvement.

BL: Once the identified risk factors are eliminated, the conservative approach may be considered the first option. Frequent monitoring during SPT is important to ensure the stability of the periodontal structures within furcations. If recurrence appears, additional care, including new instrumentation, LDD and root separation, may be appropriate.

Is chemical root treatment of benefit in furcation therapy?

Parashis 1993                     ARTICLE

Purpose: To evaluate the effect of TTC root preparation on GTR in the treatment of Class II furcation defects.

Materials and methods: 18 mandibular molars from 6 patients were included to the study. All patients had at least 2 mirror image Class II furc defects with horizontal attachment level value of 5mm or more. Initial Tx included SRP, OHI and occlusal adjustment. 6-8 later PI, GI, PD vertical and horizontal AL were recorded. During the surgical procedure one defect from each pair of furcations received tetracycline root conditioning (100mg/ml solution of tetracycline –HCl used to irrigate and scrub the root surfaces for 5 minutes). Control sites were irrigated with saline. Following that control and test defects received e-PTFE membrane. Pts were given systemic tetracycline for 7 days. 6 months post-op all clinical measurements were repeated.

Results: Clinical indices were improved and no difference was observed between the two groups. Presurgical PDs and AL were similar for the two groups. Following either Tx an improvement for all parameters was observed but changes were not statistically significant between test and control groups.

Conclusion: No additional improvement was observed in the sites treated with GTR in conjunction with TTC as compared to membrane placement alone.

How successful are the use of barrier for furcation tx?

Furca Treatment – Barriers – Non-resorbable

Pontoriero 1988                     ARTICLE

Purpose: To evaluate the regenerative potential of Class II furcations with GTR in mand molars.

Materials and methods:

• 21 pts (22-65 yo) w/bilateral Class II furcation involvement in mandibular molars (B or L). FI Class IIdefined as: FI with PAL-H >3mm.

• Initial prep completed then baseline values recorded.

• FTF, debride/degranulated, S/RP. Height and depth of furcas measured. Placed GoreTex and replaced flap, 0.12% CHX x 4 week, membrane removal after 1-2mos. Re-eval 6 mo.

• Ctrl-sx w/no mbr.

Results:

• PI, GI, BOP improved significantly post-op. 3 test and 11 controls had persistent Class II furcs.

* SSD

• 14/21 Class II furcas closed completely (test), 2/21 ctrl closed completely

• Treatment with GTR resulted in resolution of the furcation problem in more than 90%.

• Conventional therapy reached treatment goal in less than 20%.

BL: GTR does help in closure of Class II MD molar furcations.

Pontoriero & Lindhe 1995                     NO ARTICLE

P: Evaluate the clinical effects of GTR in treatment of degree II furcaction defects in max molars.

M&M: 28 patient with 28 pairs of class II furcation defects (10 B, 10 M, and 8 D); Defects were on one surface only. Test defects received OFD+ e-PTFE membrane while controls received OFD only. Assessed PI, GI, PD, PAL and recession at baseline and at 6-month re-entry. During 6 month period of healing pts were on plaque control program, which included professional tooth cleaning every 2^nd week.

R: The following results are for the test sites:

• There was very slight improvement in control sites and were NSD from baseline

• Defects that healed completely are 2 B & 1 M in test defects and 1 B in control defects.

• Overall some improvement was observed only in buccal defects of test sites.

BL: No such benefit of membrane therapy was observed at M&D furcations. Some benefits for B furcations.

Mellonig 1994                     ARTICLE

P: To evaluate the potential of GTR in the treatment of furcation defects.

M&M: 13 Patients with minimum 1 pair of bilateral teeth with class II furcations. PD, CAL were recorded before surgical & hard tissue measurements (from CEJ to Alveolar crest) were recorded at the surgery. Experimental sites received OFD+ e-PTFE membrane. Controls received OFD + coronally positioned flaps without e-PTFE membrane. Patients seen weekly for 1 month & then monthly for SPT.  At 4-6 w membranes were removed. Re-entry was done at 6m and measurements were taken.\

R:

Only 1 of the 11 mand furcation defects treated with the membrane was completely closed, and none of the sites were filled with bone. The vertical and horizontal gain was caused by tissue that had the consistency of rubber.

BL: GTR has potential as a therapeutic modality for treatment of mand class II furcation defects. Clinical parameters that influence success: root trunk, enamel projections, mandibular sites, and complete coverage of the membrane

Pontoriero 1989                     ARTICLE

P: To evaluate the regenerative potential of Cl III furcations with GTR in Mandibular Molars.

M & M: 21 pts (26-65 y/o). Bilateral Class III furcas. Initial examination, full mouth SRP, 2-3 months re-eval.

• Test: Horizontal probing attachment level to nearest 1 mm. FTF, debride/degranulated, SRP. Height and depth of furcas measured. Buccal and lingual Teflon membrane (GoreTex) was adjusted to cover the entrances of the defects. Replaced flap, 0.12% CHX BID x 4 wk, sutures removed in 10 days, Plaque control post-op q2 wks x 6 mo.

• Control same as test w/out membrane. Re-eval @ 6 mo (probing, no Sx)

RESULTS: 3 test and 11 controls had persistent Cl III furcations.

• Test grp had 21 Cl III furcas 8 closed completely, 10 closed partially, 3 had no change with GTR

• Control had none of the furcas closed completely.

• TTh w/the greatest furca surface area involved had the worst results and tth w/less than 3mm PD in mid furca had the best results so the size and height of the furc defect may be determining factors for success or failure following GTR therapy in furc defects. Wide shallow do better than narrow deep.

BL: The potential for regeneration of perio tissues in furc defects exist and there are various dimensions that should be taken into consideration when planning regeneration of furcations.

Pontoriero and Lindhe 1995                     ARTICLE

P: To study the effect of GTR therapy in small degree-III furcation defects at maxillary molars.

M&M: 11 pts w/ moderately advanced periodontitis presented with lesions on maxillary molars which involved “through-and-through” class III defects (22 pairs of furcations in total). All defects treated by one clinician. OHI and SRP was completed. Surgery was completed 3 months after initial exam and a baseline exam was performed immediately before surgery. For each patient 1 of the 2 furcation involved maxillary molars was assigned to GTR therapy and the contralateral was assigned open flap debridement. GTR was performed with an e-PTFE membrane retained with sling sutures at the two entrances of the defect. Pts were placed on amoxicillin for 7 days, chlorhexidine rinse 2xday for 4 weeks. Membranes were removed after 6 weeks. Patients were re-examined at 6 months and re-entry was performed.

R: PD reductions were SS but similar between test and control. PAL gain was not SS for either test or control. Both groups experienced SS increases in recession but not difference when comparing the two. Most sites did not change with respect to distance from the CEJ to the base of the osseous defect (21/22 test, 17/22 control).

BL: Open flap debridement and GTR procedures do not promote defect closure on maxillary molars with class III furcations.

Furca Treatment – Barriers – Absorbable

Yukna 1996                     ARTICLE

Purpose: To analyze the data from 7 treatment centers using bioabsorbable collagen membrane (Type I collagen bovine tendon) for GTR in class II furcation defects.

Materials and methods: Independent analysis on data generated from different treatment centers.

Treatment provided: After initial prep and re-eval, full-thickness flaps were reflected, the furcations associated were debrided, and roots were planed. At each center one of the two possible treatment pairs was performed: collagen membrane (COLL) vs control surgical debridement (DEBR) or COLL vs. e-PTFE membrane. Patients received quarterly periodontal maintenance until re-eval and surgical re-entry at 6-12 months (mean 11.1 months). Clinical measurements were made from fixed reference points of soft and hard tissue at standardized locations around each tooth.

PD, clinical vertical and horizontal AL gain, defect fill, %of defect resolution, crestal resorption, recession and changes in furcation involvement were evaluated and analyzed.

Results:

• 4 centers provided for COLL vs. DEBR and 3 centers for COLL vs. e-PTFE.

• COLL showed better results than DEBR for residual defect depth, defect fill, % defect resolution, residual horizontal furc depth and horizontal defect fill. When COLL was compared to e-PTFE NSSD was found.

• COLL and e-PTFE membranes resulted in improvement in clinical furcation class about 50% of the time.

• COLL use yielded the most complete furc closures (8), e-PTFE resulted to one complete furc closure and DEBR to none. DEBR had 3 cases where Class II furc. became Class III at re-eval.

Conclusion: Overall COLL resulted in the most frequent positive findings of the 3 treatments and there were no adverse effects. Results were at least similar to and often better than the –PTFE membrane.

Hugoson 1995                     ARTICLE

Purpose: To evaluate GTR therapy of Class II furcation defects with a bioresorbable matrix barrier (test) and a nonresorbable ePTFE barrier (control).

Materials and methods:

• 38 pts (34-63 yrs old) w/bilateral class II furcation defects (buccal/lingual in mandible and buccal in maxilla) who served as their own controls.

• Acrylic stent made and PI, GI, PD, recession, CAL recorded at baseline. Defects debrided and measurements made (horizontal depth of furcation-HDD, alveolar bone level-ABL, intrabony defect-IBD, and distance from CEJ to fornix).

• Surgery to place membranes; membranes were either bioresorbable matrix barrier (test group) or ePTFE(control group). Membranes covered entrance to furcation, placed adjacent to exposed root surfaces and about 3 mm wide surface of the alveolar bone apical to the bone crest. 2^nd surgery to remove nonresorbable membranes 4-6 wks later; re-exam 12 months post-sx; pts recalled every 4 weeks (continued this for 6 months).

Results:

• NSSD b/w test and control at baseline

• Post-op swelling and pain more common in control than test

• Both groups had SS reduced PD

• SS gain in CAL in both horizontal and vertical direction at test sites.

• Gain of CAL-H was 2.2mm at test sites and 1.4mm at control sites

• At test sites, gingival margin was close to pre-sx level and at control sites, recession occurred (0.9mm).

Furcation status at 12 months Test Control

BL: Both resorbable and nonresorbable membranes had SS gain of CAL at furcation areas, and both reduced PD. GTR w/ resorbable barrier resulted in SS more gain of CAL level in horizontal direction, which is the primary efficacy variable in treatment of furcation defects. Resorbable barriers also had less gingival recession. SS less post-op complications when resorbable barrier membranes used.

Cr: No antibiotics regimen.

Rosen 1997                     ARTICLE

P: To report the results of a series of maxillary Class II furcation involvements that were treated by various regenerative techniques.

M&M: Twelve patients (15 molars) are included in this report. OHI was given. SRP was performed. Radiographs and sx re-entry photographs (8 closed furcations) were taken.

Surgical procedure: FTF, debridement, citric acid conditioning for 3 mins. Intramarrow penetration, grafting+membrane, primary closure, Coe-pak, ATB

• Nine treated with DFDBA with tetracycline 4:1, and e-PTFE

• Two with DFDBA/tetracycline veneered by DFD laminar bone strip

• Two with DFDBA alone

• One with DFDBA combined with composite graft with calcium sulfate and tetracycline covered by e-PTFE

• One with DFDBA mixed with tetracycline

R: Overall success rate of 73% (clinically closed, 12-37 month follow-up). The 4 furcations that did not respond remained as class II defects. Smoker (10 cigs/day or less) 25% success rate, non-smoker 91%.

BL: Maxillary furcations can be successfully treated with predictability. Smoking appears to be critical factors in the successful closure of maxillary furcations.

Discuss the relative long-term effectiveness of various treatment modalities in the management of furcation invasions.

Hamp 1975                     ARTICLE

Purpose: To describe therapeutic procedures used for furcation – involved teeth at the University of Goteborg and analyze the periodontal status 5 years post-treatment.

Materials and methods:

• 100 patients with 310 multirooted teeth exhibiting various degrees of furcation involvements underwent complete periodontal therapy.

• Therapeutic procedures included SRP and furcation operation (debridement, odontoplasty, osteoplasty) for Class I furcation involvement and root resection, tunnel preparation and extraction for Class II and III.

• At initial exam and once every 3-6 months thereafter OHI were given and SRP and polishing of the teeth were performed. Once a year PI, GI, and PD were evaluated in the furcation areas and X-rays were taken.

Results:

• 135/310 teeth were extracted. Of the remaining, SRP only was performed in 18% of the teeth, 28% had furcation operation, 50% root resection and 4% tunnel correction.

• 110/175 treated teeth were 1^st molars, 58 2^nd molars.

• Distal root in mandibular molars was retained more often when root resection was performed.

• In 64% of the cases of root resection of max molars only one root was retained (most often the palatal).

• Significantly lower values of PI and GI scores were measured after 5 years comparing to baseline.

• 16/175 teeth subjected to furcation treatment had PD of more than 3mm. On 12 surfaces carious lesions were observed.

Conclusion: Periodontal therapy can prevent continued tissue breakdown in teeth with furc involvement.

Kalkwarf 1988                    ARTICLE

Purpose: To evaluate the longitudinal clinical response of furcation regions to 4 types of periodontal therapy.

M&M:

• 82 pts with 1,394 furcation sites (556 1^st and 2^nd molars).

• Molars in each quadrant were randomly assigned to 1 of 4 therapy modalities: CS (coronal scaling), RP (root planing), MW (modified Widman), FO (flap with osseous resection).

• PD, PAL, Horizontal probing attachment level were recorded following therapy and two yr follow up.

Results:

• All therapies were effective in reducing PDs (in order of effectiveness): FO, MW, RP, and CS.

• A mean net loss of horizontal probing attachment was present after 2 years regardless of the therapy.

• FO treated teeth demonstrated a lesser percentage of furcation sites demonstrating clinically significant breakdown during the two years of maintenance.

BL: All tx modalities decreased PD and improved vertical attachment loss in furcation regions at 1 and 2 yrs. Furcation sites tended to exhibit loss of probing attachment regardless of tx.

Muller 1995                     ARTICLE

P: To present data which may indicate the influence of operator experience, degree of furcation involvement, and tooth type on the decision for a certain mode of therapy of periodontitis affected multi-rooted teeth.

M&M: More than 550 mod – advanced perio pts (16-72 Y/O) w/ more than 1100 furcation invasions retrospectively analyzed (PD, rec, BOP, PI, MO, FI). These patients were treated by 2 operators from 1987-1994. One operator was a fully trained periodontist and the other was still in residency.

R: There were apparent differences in the distribution of varying furcation degrees in pts treated by 2 experienced operators. However, treatment modality patterns were rather similar. Scaling during flap surgery was the most often performed treatment in degree I (97-98%) and II (75-83%) involvements. About 44% of degree III involved teeth were extracted. In order to determine the influence of degree of furcation involvement, tooth type and operator variability on tx modality, logistic regression analysis was applied. Degree of furcation involvement was an important indicator variable in all models. Scaling as a sole measure was mainly performed in relation to first degree furcation involvement. With every increase in degree, the odds of scaling decreased by a factor of 12.7. The odds of root resection in max 1^st molars was 46X higher than in wisdom teeth or mand 2^nd molars with the same degree of involvement, but only 3.3X higher than in mand 1^st molars. Tunnel prep as well as regenerative procedures were mainly confined to mand molars. Operator variability was only introduced as a covariate in the extraction model.

BL: Despite diff operator skill and severity of perio disease in treated populations, decision for treatment modalities seems to depend essentially on degree of furcation involvement as well as tooth type.

Evans 1996                     ARTICLE

P: to evaluate the literature and determine the frequency with which various regenerative therapies have been reported to achieve clinical closure of Grade II furcations.

M: 50 papers involving 1,016 cases were evaluated.

• Complete furcation closure was reported in approx. 20% of the cases, while a change to Grade I (partial furcation fill) was reported in about 33% of the cases.

• The most effective furcation regenerative therapy reported was the combination of GTR (with Gortex membrane) plus BRG (91% overall positive).

• 88% were achieved with nondemineralized FDBA plus tetracycline (TTC) without a barrier.

• >75% overall improvement were with BRG groups.

• The least effective therapy was open flap debridement (OFD) – 2% complete closure and 13% partial closures.

C: Some positive change in Grade II furcations can be accomplished to a limited degree.

BL: Most effective furcation regenerative therapy (91%) was GTR (with Gortex membrane) + BRG, very similar results (88%) were achieved with FDBA + TTC and >75% was achieved with BRG group. Least effective therapy was with OFD.

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