QUINTESSENCE INTERNATIONAL GENERAL

Adrian Kasaj Root resective procedures vs implant therapy in the management of furcation-involved molars

Adrian Kasaj, PD Dr med dent1

Therapeutic decision making and successful treatment of fur- ment, the clinician is increasingly confronted with the dilemma cation-involved molars has been a challenge for many clin- of whether to treat a furcated by traditional root resec- icians. Over recent decades, several techniques have been tive techniques or to extract the and replace it with a advocated in the treatment of furcated molar teeth, including dental implant. This article reviews the outcomes of root resec- nonsurgical periodontal therapy, regenerative therapy, and tive therapy for the management of furcation-involved multi- resective surgical procedures. Today, root resection is consid- rooted teeth and discusses treatment alternatives including ered a relevant treatment modality in the management of fur- implant therapy. Treatment guidelines for root resective thera- cation-involved multirooted molars. However, root resective py, along with advantages and limitations, are presented to procedures are very technique-sensitive and require a high help the clinician in the decision-making process. level of periodontal, endodontic, and restorative expertise. (Quintessence Int 2014;45:521–529; doi: 10.3290/j.qi.a31806) Given the high documented success rates of implant treat-

Key words: furcation involvement, furcations, molar, , root resection

The management and long-term retention of furcated teeth without furcation involvement.3,4 Even with a molar teeth has always been a challenge for clinicians. surgical approach selected to improve access for root Furcation involvement is defined as interradicular bone surface debridement, complete calculus removal in the resorption and attachment loss in multirooted teeth furcation area is rare.5 The compromised results in fur- caused by periodontal disease. The interradicular space cation areas can be attributed to the limited accessibil- of the molar teeth is inaccessible for proper mainte- ity of the furcation entrances for complete debride- nance, and long-term stability of molars with furcation ment as well as the complex anatomy and morphology involvement is compromised. Thus, maxillary molars of molar teeth.6 Moreover, the morphology of the fur- are the most common teeth lost, followed closely by cation area provides an environment favorable to bac- mandibular molars.1,2 In addition, furcation-involved terial deposits, which hampers professional as well as multirooted teeth generally respond less favorably to self-performed plaque control.7 treatment compared with single-rooted teeth or molar Various therapeutic approaches have been intro- duced for several decades that aim to retain furcation-

1 Associate Professor, Department of Operative Dentistry and Periodontology, involved molars, including nonsurgical and surgical School of Dental Medicine, University of Mainz, Mainz, Germany. mechanical debridement, regenerative therapy, and Correspondence: Dr Adrian Kasaj, Department of Operative Dentistry resective surgical procedures. Root resection is one and Periodontology, University of Mainz, School of Dental Medicine, Augustusplatz 2, 55131 Mainz, Germany. Email: [email protected] treatment option for preserving molars with furcation

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involvement. Through root resection therapy, furcation- Tarnow and Fletcher12 later on further described the involved molars can be converted to nonfurcated/sin- extent of furcation involvement with a subclassification gle root teeth and provide a favorable environment for evaluating the degree of vertical involvement: oral hygiene maintenance by eliminating plaque reten- • Subclass A, 1–3 mm tive morphology. The procedure of root resection has • Subclass B, 4–6 mm been used in the treatment of furcation-involved • Subclass C, ≥ 7 mm. molars for more than 100 years.8 However, the interest in root resective procedures has declined in recent Molar root anatomy years due to complications and failures and the fact that The practitioner must have a thorough understanding modern implant dentistry has modified the treatment of the complex furcation anatomy for accurate diagno- planning process. Indeed, it seems that today furcation- sis and selection of treatment modalities. Thus, several involved molars are extracted more frequently in favor problematic anatomical features exist in multirooted of implant placement. Thus, today the ethically oriented teeth such as furcation entrance width, presence of practitioner is challenged with the question whether to root concavities, bifurcation ridges, root trunk length, treat furcation-involved molars by “traditional” root cervical enamel projections, and enamel pearls (Fig 1).14 resective techniques or to replace it with an implant. The diameter of the furcation entrance was evaluated This paper will review root resection procedures as by Bower,15 with the majority of entrances measuring well as the different therapeutic alternatives, especially < 0.75 mm. Considering that the blade width of com- implant therapy, for furcation-involved molars. Treat- monly used periodontal curettes ranges from 0.75 mm ment guidelines for root resective therapy, indications, to 1.10 mm, it is unlikely that proper debridement of and contraindications are presented to help the practi- the furcation area can be achieved with curettes alone tioner in the decision-making process with regards to (Fig 2). Moreover, efficacy of periodontal therapy in the furcation-involved molars. furcation area may be limited by the presence of root concavities and ridges in the interradicular root surface Furcation involvement classification area.15,16 The position of the furcation entrance, particu- The glossary of periodontal terms defines furcation as larly in maxillary molars, is also important with respect “the anatomic area of a multirooted tooth where the to accessibility. Thus, the mesiopalatal entrance of the roots diverge” and furcation invasion refers to the first maxillary molar is located approximately two thirds “pathologic resorption of bone within a furcation”.9 towards the palatal aspect of the tooth, while the disto- Several classification schemes have been introduced to palatal furcation is in the middle portion of the tooth. describe the degree of periodontal tissue destruction in Therefore, a buccal or palatal approach can be used the interradicular area. Most of them are based on the when probing the distopalatal furcation, whereas a extent of periodontal destruction in a horizontal and/or palatal approach is indicated when probing the mesio- vertical direction.10-12 A simple and commonly used palatal furcation. Another important factor that affects system is Hamp’s classification,13 defining periodontal the development of furcation involvement and the destruction in a horizontal direction. Three different mode of treatment is the length of the root trunk. This classes of severity were identified: length is defined as the distance between the cemento- • Class I, horizontal loss of periodontal tissue support enamel junction and the furcation. In a tooth with a < 3 mm short root trunk less attachment needs to be lost before • Class II, horizontal loss of support > 3 mm, without the furcation is involved. On the other hand, a tooth extending through the opposite side with a short root trunk is more amenable to root resec- • Class III, horizontal through-and-through destruc- tive procedures and is also more accessible to mainte- tion of periodontal tissue in the furcation. nance procedures compared to teeth with a longer

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d e f Figs 1a to 1f Root anatomy of mandibular and maxillary molars. (a) A cross-sectioned mandibular molar with the mesial root char- acterized by root concavities on the mesial and distal surfaces, whereas the distal root is more robust and has only a minimal concav- ity on the mesial aspect of the root. (b) Third mandibular molar with pronounced curved roots and a short supernumerary root. (c) A maxillary molar with a narrow furcation entrance between the buccal roots and concave and convex areas in the interradicular root surface area. (d) Maxillary molar with fused roots and (e) roots that diverge coronally but fuse apically. (f) in the furcation entrance area.

Figs 2a and 2b (a) An extracted man- dibular molar used to demonstrate that the entrance of the furcation is often nar- rower than the width of the curette blade. (b) Preference should be given to slim ultrasonic scaler tips to enable greater access and efficient periodontal debride- a b ment in the furcation area. root trunk. Alternatively, the furcation of a tooth with a with or without furcal involvement was 82.5% and long root trunk will be invaded at a later stage, but suc- 17.5%, respectively. Thus, cervical enamel projections cessful resective therapy is not as predictable because can be considered as an important predisposing factor the length of the remaining roots may not be sufficient in the initial furcation invasion due to the lack of fiber for support. Other important anatomical variations that attachment on the enamel extensions. However, the can be considered as local cofactors in causing furca- presence of cervical enamel projections is often difficult tion lesions include cervical enamel projections and to detect for the clinician, especially in the non-dis- enamel pearls. The cervical enamel projection has been eased dentition. The other category of defined as an extension of the cervical enamel margin formation with lower prevalence is the enamel pearl. either toward or into the root furcation area.17 They are Similarly to cervical enamel projections, enamel pearls most commonly found on the buccal surfaces of man- prevent the formation of a connective tissue attach- dibular molars.18 Hou and Tsai19 revealed the presence ment and thus contribute to the etiology of furcation of cervical enamel projections in 45.2% of the molars. involvement. The prevalence of cervical enamel projections in molars

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Diagnosis of furcation involvement in molars which is imaged by both panoramic as well as peri-api- An accurate diagnosis of furcation involvement is cal radiographs has been found to underestimate the essential for adequate choice of treatment, tooth prog- actual amount of bone destruction.23 Ross and Thomp- nosis, and maintenance procedures. The diagnosis of son21 reported that the diagnosis of furcation involve- furcation involvement is generally based upon probing ment based on the radiographic appearance alone was and radiographic findings. Although a straight peri- possible in only 22% of cases. Some weak evidence for odontal probe may be used, detection of subgingival advanced furcation involvement in maxillary molars furcations is best accomplished using a curved, color- may be provided by a small, triangular radiolucent coded probe, eg Nabers (PQ2N, Hu-Friedy). Unfortu- shadow across the mesial or distal roots of these teeth, nately, horizontal measurements are often difficult to the so-called furcation arrow.24 More recently, however, assess and it may not be possible to probe the furcation Deas et al25 reported that in cases where furcation in its entirety. Thus, two opposite furcations classified involvement was truly present, the furcation arrow was as degree II by the practitioner actually may be a true seen in less than 40% of sites. Thus, it appears that con- degree III furcation. Indeed, Zappa et al20 found differ- ventional radiographs alone are of limited value in the ences between surgical and clinical measurements of diagnosis of furcation defects. With the introduction of up to 9 mm, which means that the magnitude of the cone beam computed tomography (CBCT), a more discrepancy between clinical and surgical values accurate and detailed imaging of periodontal destruc- encompassed 2 degrees of involvement. A classic study tion seems possible. In a more recent study, Walter et by Ross and Thompson21 demonstrated that the detec- al26 reported that CBCT and intrasurgical assessment of tion of furcation involvement by clinical examination maxillary molar furcation involvement were found to be alone occurred in only 3% of maxillary and 9% of man- in substantial agreement. Overall, 84% of the CBCT data dibular molars. The use of presurgical transgingival were confirmed by the intrasurgical findings. The probing or bone sounding may help to improve diag- authors concluded that CBCT provides high accuracy in nosis of furcation involvement by providing a more assessing the loss of periodontal tissues and classifica- accurate assessment of underlying bony contours. tion of furcation involvement. Mealey et al22 reported that post-anesthesia bone In practice, periodontal diagnosis of furcation sounding significantly improved the diagnostic accu- involvement is best accomplished using a combination racy of furcation involvement compared to standard of radiographs, periodontal probing with a curved pre-anesthetic probing. Taken together, these findings explorer or Nabers probe, and bone sounding.27 indicate that periodontal probing of furcation areas is an error-prone task, which might be due to disease- Root resection therapy of related alterations of periodontal tissues and the com- furcation-involved molars plex anatomy of multirooted teeth. A wide range of treatment modalities for multirooted Radiographs are commonly taken as an adjunct in teeth with furcation involvement has been suggested diagnosis of furcation involvement. The advantages are based on the depth of furcation involvement.28 Thus, that important information may be gained with regard for teeth with shallow furcation defects recommended to the anatomy and topography of the root complex therapies include nonsurgical/surgical scaling and root (number and form of roots, separation degree, diver- planing with or without furcation plasty. For furcations gent roots), as well as the neighboring teeth and ana- with advanced degree of involvement, root resection, tomical structures. However, one of the main draw- tunnel preparation, regenerative procedure, or tooth backs of using conventional radiographs is the overlap extraction are the treatments of choice. The procedure of anatomical structures and lack of three-dimensional of root resection was first introduced by Farrar8 in 1884 (3D) information. Moreover, the amount of bone loss as “radical and heroic”, and since then has been com-

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Figs 3a and 3b Intraoperative view of a right maxillary first molar with a root prox- imity and a degree II distopalatal furcation involvement. While the second maxillary molar is hopeless and should be extracted, a root amputation of the distobuccal root of the first molar can be performed. (a) The root trunk is short and the remaining roots exhibit sufficient bone support. (b) In con- trast, the high root trunk and the insuffi- cient bone support of the mesiobuccal root make this left maxillary first molar a abpoor candidate for root-resective therapy. monly used as a treatment modality for molars with mainly related to endodontic complications and root advanced furcation involvement. In the current litera- fractures and not to periodontal disease recurrence. ture there is no uniformity in the terms used for root The significant variations in the success rates may, at resective techniques. Root resection generally is least in part, be attributed to different inclusion criteria, defined as the removal of a root without reference to outcome definitions, follow-up periods, maintenance how the crown is treated.28 The surgical removal of a program, and the methods of restoration of the tooth. root without its accompanying portion of the crown is Since there is no consensus for the inclusion criteria, referred to as root amputation. Trisection is defined as some studies may have retained more questionable the surgical removal of a maxillary molar root together teeth, which may have led to less favorable success with the corresponding part of the clinical crown, rates, while others extracted them during initial peri- whereas the same procedure is called a “hemisection” odontal therapy. Indeed, Hamp et al13 described a when performed on a mandibular molar. Root separa- 5-year follow-up of periodontal treatment of multi- tion is indicated as the sectioning of the root complex rooted teeth, with 44% of all teeth with furcation and the maintenance of all roots.17 Commonly accepted involvement being extracted as part of the initial treat- indications for root resective procedures include: ment. In contrast, Lee et al30 used root resection as a • class II or III furcation involvement “last resort” therapy, including teeth that presented • severe bone loss affecting one or more roots with pretreatment < 50% radiographic bone support. • severe root proximity to an adjacent tooth A high success rate of this treatment approach was • severe recession or dehiscence of a root commonly related to appropriate periodontal therapy, • root fracture or perforation, root resorption, deep successful endodontic treatment, and proper restor- root caries ation design. Moreover, all authors emphasize the • elimination of an endodontically failed or untreat- importance of meticulous patient oral hygiene and able root. regular maintenance care for the resected molars to prevent periodontal disease. The prognosis of root resection has been well docu- Root resection is very technique-sensitive and com- mented, but a considerable heterogeneity is noticeable plex, therefore proper case selection is essential (Fig 3). when comparing the different studies. In a recent sys- The following tooth-specific factors should be consid- tematic review on the effect of periodontal therapy on ered when deciding which root should be retained: the the survival of multirooted teeth with furcation involve- degree of periodontal destruction and furcation ment, Huynh-Ba et al29 reported a success rate for root involvement, the root and root canal anatomy, end- resection therapy ranging from 62% to 100% after an odontic conditions, periapical condition, and the mobil- observation period of 5 to 13 years. The authors con- ity of each separated root (Fig 4).13 A recent investiga- cluded that the reasons for tooth extraction were tion by Lee et al,30 reported an increased risk for early

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c d e Figs 4a to 4e (a) Baseline clinical situation following nonsurgical periodontal therapy and of a maxillary right first molar requiring distal root resection. (b) Intraoperative view after flap elevation, a degree II distobuccal furcation involvement is evident. (c) Amputation of the distobuccal root while leaving the entire crown intact. A smooth, flat surface is established at the resec- tion site to avoid any residual plaque-retentive subgingival overhangs. (d) Suture and flap closure. (e) Clinical situation 2 years follow- ing root resective therapy and regular supportive periodontal care. tooth loss following resective periodontal therapy if the maintenance and restorative procedures. Therefore, an affected molars exhibited pre-resective mobility of adequate soft tissue width between the restorative degree II or above. Park et al31 demonstrated that margin and the osseous crest should be established molars with bone support > 50% of the remaining roots during surgery, and irregular root contours have to be at the time of root resection had a significantly higher carefully evaluated and eliminated. Carnevale et al28 survival rate than those with < 50% bone support. suggested osseous recontouring and apically pos- Moreover, the authors reported that following root itioned flaps in order to establish a favorable environ- resection, maxillary molars had more periodontal fail- ment for oral hygiene. ures, whereas the mandibular molars had more root Root resection therapy in mandibular molars fractures and dental caries. Newell32 attributed the requires some additional considerations. A mandibular higher failure rate in the maxilla to residual root frag- first molar typically presents with two well-defined ments, furcation lips, and ledges that were not readily roots. Most commonly, two root canals are located in observed in the radiographs of the maxilla. These sub- the mesial root and one canal in the distal root.34 The gingival structures can easily lead to plaque accumula- mesial root is characterized by prominent root depres- tion and disease recurrence.17 Thus, following root sions on the mesial and distal surfaces giving the root a resection a flat contour that follows the root morphol- figure-eight shape in cross section, a widened buccolin- ogy is essential for the establishment of an environ- gual surface, and a root curvature to the distal.35 In ment conducive to the maintenance of adequate contrast, the distal root is usually less curved than the plaque control. Majzooub and Kon33 reported that 86% mesial root. Therefore, the mesial root is more difficult of distobuccal root-resected maxillary first molars will to treat endodontically, and the mesial root concavities leave less than 3 mm of available root structure in this are less accessible for plaque control. Thus, removal of area. Only 6% of the resected molars had an overall the mesial root is preferred over the distal root for root topography that was easily amenable to periodontal resection. Indeed, fracture of the resected mandibular

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molar is more frequent when the mesial root is Root resection therapy vs retained.36,37 The remaining single root following resec- endosseous implants tion is insufficient to maintain the occlusion of a man- It is obvious that root resective therapy has a high dibular molar. Therefore, the remaining root should be degree of complexity, which contributes to the vari- incorporated into a more extended fixed dental pros- ability in reported clinical outcomes. Thus, the question thesis, rather than restoring it with a single crown with can be raised whether the use of dental implants after a mesial or distal cantilever. Moreover, the use of posts extraction of furcation-involved molars may provide a and cores should be avoided if possible to minimize the more predictable alternative to root resective therapy. chance of root fracture.38 Fugazzotto37 compared the success rates of root- Additional factors to consider when evaluating resected molars and implants placed in the molar treatment outcomes include the strategic value of the region for a period of up to 15 years. Resection of the tooth in relation to the overall treatment plan, patient’s distal root of a mandibular molar demonstrated the age, general health conditions, and oral hygiene stan- lowest success rate (75%), whereas all other success dards.7,30,39 rates for various root resected molars in function Considering all these parameters, the clinician is ranged from 95.2% to 100%. In comparison, lone stand- often faced with a dilemma when deciding whether or ing implants in second molar positions demonstrated not to extract a furcation-involved molar. It should be the lowest success rate (85%), while all other implants emphasized that it is generally difficult to determine in molar positions had a success rate of 97.0% to 98.6%. the precise long-term prognosis of furcation involved Cumulative success rates were 96.8% for root resected molars in advance. Indeed, McGuire40 reported that molars and 97.0% for molar implants. Thus, molar root- initial prognosis based on common clinical parameters resection therapy displayed a success rate comparable did not adequately predict tooth survival, particularly with that of implant placement. In contrast, Zafiropou- that of molar teeth. Recently, Miller et al41 introduced a los et al42 retrospectively reported that 32.1% of post- quantitative scoring system to determine the long- treatment complications occurred in hemisected term prognosis of periodontally involved molars. This molars compared to 11.1% in molar implants after ≥ 4 scoring index is based on data from 816 molars in 102 years. Moreover, most of the posttreatment complica- patients with a minimum of 15 years post treatment. tions in hemisected molars were not salvageable and The factors evaluated include age, probing depth, included root caries, apical abscesses, and root fracture. mobility, furcation involvement, smoking, and molar On the other hand, almost all post-treatment complica- type. The authors reported that molars with lower tions in molar implants were salvageable. The authors scores (1 to 3) exhibited a 15-year survival rate of 98% concluded that implants replacing furcation-involved to 96%, whereas in molars with higher scores (7 to 10) molars exhibit fewer complications than hemisected the survival rates ranged from 86% to 67%. However, mandibular molars. Kinsel et al43 reviewed the treat- one should be aware that such a scoring system does ment of furcation-involved molars comparing root- not consider factors like clinical experience, therapeutic resection versus single-tooth implants. The reported skills, and patient compliance. Therefore, it seems dif- failure rate was 15.9% for root-resection therapy com- ficult to objectively determine the prognosis of furca- pared to 3.6% for single implants. Hence, the authors tion involved molars based on such a scoring system, concluded that root-resection therapy shows poor and the decision to extract a furcated molar remains a long-term results unless a high level of expertise is sophisticated process. available in all applicable disciplines. In addition, it was suggested that surgical and restorative procedures related to implant placement may be less difficult than management with root resective therapy.

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Although a direct comparison between the two be considered a valuable treatment modality for furca- treatment approaches is difficult, a couple of variables tion-involved molars. A proper case selection and care- should be considered by the practitioner. Following ful interdisciplinary approach including periodontal tooth extraction of a periodontally compromised maxil- therapy, endodontic treatment, prosthetic reconstruc- lary molar the amount of the remaining crestal bone is tion, and supportive periodontal care are essential for further reduced due to vertical ridge resorption and successful treatment outcomes. When root resective increased pneumatization of the maxillary sinus. Fur- procedures are rendered appropriately, furcation- thermore, a significant implant failure in the posterior involved molars can be maintained for prolonged peri- maxilla has been noted due to the very spongious bone ods of time displaying a success and longevity rate quality found in this area.44 Similarly, in the mandibular comparable with that of implant placement. Since molar area the position of the inferior alveolar nerve dental implants are not devoid of complications, root may limit the amount of bone available for dental resective procedures should be considered for the implants. Therefore, in these cases bone augmentation retention of furcation-involved molars to optimize the procedures (simultaneous or staged approach) are longevity of the dentition before extraction and required. In contrast, teeth in proximity to anatomical replacement with a dental implant is undertaken. landmarks can be treated safely by root-resection ther- apy. Furthermore, the maintenance of a furcation- REFERENCES involved molar in an inflammation-free environment 1. Hirschfeld L, Wassermann B. A long-term survey of tooth loss in 600 treated will prevent resorptive processes, thereby not preclud- periodontal patients. J Periodontol 1978;49:225–237. ing implant placement in the future. One should be 2. McFall WT Jr. Tooth loss in 100 treated patients with periodontal disease. A long-term study. J Periodontol 1982;53:539–549. also aware that biological and technical long-term 3. Nordland P, Garrett S, Kiger R, Vanooteghem R, Hutchens LH, Egelberg J. The complications associated with dental implants are fre- effect of plaque control and root debridement in molar teeth. J Clin Periodon- tol 1987;14:231–236. quent. Indeed, Simonis et al45 followed up 162 implants 4. Loos B, Nylund K, Claffey N, Egelberg J. Clinical effects of root debridement in for 10 to 16 years and reported a cumulative complica- molar and non-molar teeth. A 2-year follow-up. J Clin Periodontol 1989;16:498–504. tion rate of 48.03%. Furthermore, patients with a his- 5. Parashis AO, Anagnoou-Varetzides A, Demetriou N. Calculus removal from tory of periodontitis had lower implant survival rates multirooted teeth with and without surgical access. II. Comparison between external and furcation entrance width. J Clin Periodontol 1993;20:71–77. than patients without a history of periodontitis and 6. Wang HL, Burgett FG, Shyr Y, Ramfjord S. The influence of molar furcation were more prone to biological complications such as involvement and mobility on future clinical periodontal attachment loss. J Periodontol 1994;65:25–29. peri-implant mucositis and peri-implantitis. Finally, 7. Svärdström G, Wennström JL. Periodontal treatment decision for molars: an root-resection therapy may be a more viable treatment analysis of influencing factors and long-term outcome. J Periodontol 2000;71:579–585. option than implant therapy in medically compromised 8. Farrar JN. Radical and heroic treatment of alveolar abscess by amputation of patients, thus avoiding several surgical procedures. roots of teeth. Dent Cosmos 1884;26:79. 9. American Academy of Periodontology. Glossary of Periodontal Terms, 4th ed. Chicago: American Academy of Periodontology, 2001:20. 10. Glickman I. Clinical Periodontology, 1st ed. Philadelphia: WB Saunders, 1953. CONCLUSION 11. Goldman HM. Therapy of the incipient bifurcation involvement. J Periodontol 1958;29:112. The successful long-term management of the furca- 12. Tarnow D, Fletcher P. Classification of the vertical component of furcation tion-involved molar remains a major clinical challenge involvement. J Periodontol 1984;55:283–284. 13. Hamp SE, Nyman S, Lindhe J. Periodontal treatment of multirooted teeth. in periodontal treatment. As yet, there are no rules or Results after 5 years. J Clin Periodontol 1975;2:126–135. scores to provide a straightforward answer in the deci- 14. Al-Shammari KF, Kazor CE, Wang HL. Molar root anatomy and management sion-making process for furcation-involved molars. The of furcation defects. J Clin Periodontol 2001;28:730–740. 15. Bower RC. Furcation morphology relative to periodontal treatment. Furcation choice of treating a furcated molar should be based on entrance architecture. J Periodontol 1979;50:23–27. patient-, tooth-, and prognostic-related factors. Root 16. Svärdström G, Wennström JL. Furcation topography of the maxillary and mandibular first molars. J Clin Periodontol 1988;15:271–275. resective therapy is a predictable procedure and should

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17. DeSanctis M, Murphy KG. The role of resective periodontal surgery in the 32. Newell DH. The role of the prosthodontist in restoring root-resected molars: a treatment of furcation defects. Periodontol 2000 2000;22:154–168. study of 70 molar root resections. J Prosthet Dent 1991;65:7–15. 18. Mandelaris GA, Wang HL, MacNeil RL. A morphometric analysis of the furcation 33. Majzooub Z, Kon S. Tooth morphology following root resection procedures in region of mandibular molars. Compend Contin Educ Dent 1998;19:113–116. maxillary molars. J Periodontol 1992;63:290–296. 19. Hou GL, Tsai CC. Relationship between periodontal furcation involvement 34. dePablo OV, Estevez R, Heilborn C, Cohenca N. Root anatomy and canal con- and molar cervical enamel projections. J Periodontol 1987;58:715–721. figuration of the permanent mandibular first molar: clinical implications and 20. Zappa U, Grosso L, Simona C, Graf H, Case D. Clinical furcation diagnoses. J recommendations. Quintessence Int 2012;43:15–27. Periodontol 1993;64:219–227. 35. Saraf AA, Patil AC. Hemisection. World J Dent 2013;4:180–187. 21. Ross I, Thompson RH Jr. Furcation involvement in maxillary and mandibular 36. Langer B, Stein SD, Wagenberg B. An evaluation of root resections. A ten-year molars. J Periodontol 1980;51:450–454. study. J Periodontol 1981;52:719–722. 22. Mealey BL, Neubauer MF, Butzin CA, Waldrop TC. Use of furcal bone sounding 37. Fugazzotto PA. A comparison of the success of root resected molars and to improve accuracy of furcation diagnosis. J Periodontol 1994;65:649–657. molar position implants in function in a private practice: results of up to 23. Akesson L, Hakansson J, Rohlin M. Comparison of panoramic and intraoral 15-plus years. J Periodontol 2001;72:1113–1123. radiography and pocket probing for the measurement of the marginal bone 38. Abou-Rass M, Jann JM, Jobe D, Tsutsui F. Preparation of space for posting: level. J Clin Periodontol 1992;19:326–332. effect on thickness of canal walls and incidence of perforation in molars. J Am 24. Hardekopf JD, Dunlap RM, Ahl DR, Pelleu GB Jr. The “furcation arrow”. A reli- Dent Assoc 1982;104:834–837. able radiographic image? J Periodontol 1987;58:258–261. 39. Yuh DY, Cheng GL, Chien WC, et al. Factors affecting treatment decisions and 25. Deas DE, Moritz AJ, Mealey BL, McDonnell HT, Powell CA. Clinical reliability of outcomes of root-resected molars: a nationwide study. J Periodontol the “furcation arrow” as a diagnostic marker. J Periodontol 2006;77:1436–1441. 2013;84:1528–1535. 26. Walter C, Weiger R, Zitzmann NU. Accuracy of three-dimensional imaging in 40. McGuire MK. Prognostic versus actual outcome: A long-term survey of 100 assessing maxillary molar furcation involvement. J Clin Periodontol treated periodontal patients under maintenance care. J Periodontol 2010;37:436–441. 1991;62:51–58. 27. Kalkwarf KL, Reinhardt RA. The furcation problem. Current controversies and 41. Miller PD Jr, McEntire ML, Marlow NM, Gellin RG. An evidence-based scoring future directions. Dent Clin North Am 1988;32:243–266. index to determine the periodontal prognosis on molars. J Periodontol 2014;85:214–225. 28. Carnevale G, Pontoriero R, Hürzeler MB. Management of furcation involve- ment. Periodontol 2000 1995;9:69–89. 42. Zafiropoulos GG, Hoffmann O, Kasaj A, Willershausen B, Deli G, Tatakis DN. Mandibular molar root resection versus implant therapy: a retrospective 29. Huynh-Ba G, Kuonen P, Hofer D, Schmid J, Lang NP, Salvi GE. The effect of nonrandomized study. J Oral Implantol 2009;35:52–62. periodontal therapy on the survival rate and incidence of complications of multirooted teeth with furcation involvement after an observation period of 43. Kinsel RP, Lamb RE, Ho D. The treatment dilemma of the furcated molar: root at least 5 years: a systematic review. J Clin Periodontol 2009;36:164–176. resection versus single-tooth implant restoration. A literature review. Int J Oral Maxillofac Implants 1998;13:322–332. 30. Lee KL, Corbet EF, Leung WK. Survival of molar teeth after resective periodon- tal therapy – a retrospective study. J Clin Periodontol 2012;39:850–860. 44. Jaffin RA, Berman CL. The excessive loss of Branemark fixtures in type IV bone: a 5-year analysis. J Periodontol 1991;62:2–4. 31. Park SY, Shin SY, Yang SM, Kye SB. Factors influencing the outcome of root- resection therapy in molars: a 10-year retrospective study. J Periodontol 45. Simonis P, Dufour T, Tenenbaum H. Long-term implant survival and success: 2009;80:32–40. a 10-16-year follow-up of non-submerged dental implants. Clin Oral Implants Res 2010;21:772–777.

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