Considerations for furcation treatment Part I: Diagnosis and treatment planning

SECTIOh

SAMUEL WILLIAM

EDITORS

F. GUYER

WILLIAM

F. P. MALONE.

LEFKOWITZ JOHN

ROBERT

E. RHOADS

C. SF’ROULL

Considerations for furcation treatment. Diagnosis and treatment planning Robert University

F. Baima, D.D.S.* of Medicine

and

Dentistry,

New

Jersey

Dental

School,

A

difficult problem in periodontic-prosthodontic treatment is the diagnosis and treatment of the molar furcation. Knowledge of the anatomy of furcations is necessary to formulate a treatment plan and determine the prognosis. This article will review the periodontal and restorative considerations of molar teeth with furcation involvement. MAXILLARY

MOLARS

Maxillary molars usually have a mesiobuccal root, a distobuccal root, and a palatal root. There are variations but three roots are considered normal. The .mesiobuccal root is biconcave and commonly curves to the distal in first molars. The distobuccal root is biconcave but less curved. The palatal root is thick buccolingually and mesiodistally. The root is lingually divergent to the crown of the tooth, which is exceptional in the human dentition. This root presents unique

*Assistant

Part I:

Professor

of Periodontics

and Restorative

Dentistry.

Newark,

h .J.

problems of tooth preparation, restoration, contour, and o’cclusal design to the dentist. Maxillary trifurcation anatomy. The distobuccal and palatal roots of maxillary molars are in the same plane on the distal surfaces. The distal furcation is more apically located on the tooth compared with the mesial furcation (Figs. I. through 3). Despite this anatomy, the distal furcation is more commonly involved with periodontal problems than the mesial furcation.’ From the apical view, a groove tends to unite the buccal and mesial opening o!f the trifurcation. This groove can be probed clinically when there is communication with the furcation. MANDIBULAR

MOLARS

Mandibular molars usually have distal and mesial roots. They are similar to the maxillary molars, but there are variations in anatomy (Fig. 4). The mesial root is flattened buccolingually, with concave surfaces on each proximal side. The mesial root curves to the distal. The distal root is wider buccolingually than the mesial

Fig. 1. Anatomy of typical maxillary first molar with mesiobuccal, distobuccal, and palatal roots. Although distopalatal furcation is in a more apical position on teeth than mesiopalatal furcation (end section of illustration), distopalatal furcation is more often periodontally involved. M = mesiobuccal; D = distobuccal; B = buccal. (From Abrams L, Trachtenberg DI: Hemisection-Technique and restoration. Dent Clin North Am 18:415, 1974. Reprinted with permission from W.B. Saunders Co.) 138

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Fig. 2. Apical view of anatomy of maxillary first molar. Roots curve toward body of tooth, and concavities are present in root structure, making plaque control difficult. B = buccal; M = mesiobuccal; LI = lingual; D = distobuccal. (From Abrams L, Trachtenberg DI: Hemisection-Technique and restoration. Dent Clin North Am 18:415, 1974. Reprinted with permission from W.B. Saunders co.‘,

Fig. 3. Apical view of maxillary second molar. Roots tend to fuse as tooth position progresses distally in arch. B = buccal; M = mesiobuccai; D = distobuccal. (From Abrams L, Trachtenberg DI: Hemisection-Technique and restoration. Dent Clin North Am 18:415. 1974. Reprinted with permission from W.B. Saundtsrs Co.)

root and concave on the mesial surface. The apex of the distal root is often curved to the distal, with a flat or a convex distal root. Mandibular bifurcation anatomy. The root surfaces facing the furcation are both concave, resulting in a wider mesial-distal osseous chamber than either the buccal or lingual furcation opening. The roof of the furcation is difficult to maintain because of bifurcation ridges traveling me&distally on the roof of the furca2 (Figs. 5 and 6). The furcation is more apically positioned as the tooth is more distally located in the dental arch.

MAXILLARY

PREMOLARS

Although maxillary premolars also have furcations,‘.’ they are not commonly treated with amputation procedures.

Class of furcation

involvement

The normal location of the osseous structure in health is approximately 1.5 mm apical to the cementoenamel junction (Fig. 7). Degree (class) I. This class involves horizontal loss of tissue less than 3 mm apical to the cementoenamel junction.’ There is involvement of the furcation, but without radiographic evidence of bone 10~s.~Clinically, the furcation can barely be probed (Fig. 8). THE

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Fig. 4. Radiograph

of typical mandibular first molar with mesial and distal roots. (From Caranza FA Jr, editor: Glickman’s Clinical Periodontology, ed 6. Chicago, W.B. Saunders Co., with permission )

139

BAIMA

Fig. 5. Apical view of mandibular first molar anatomy. Mesial root usually has two canals yielding a figure-8 shape to root. Concavity at distal of mesial root makes plaque control difficult. D = distal; M = mesial. (From Abrams L, Trachtenberg DI: Hemisection-Technique and restoration. Dent Clin North Am 18415, 1974. Reprinted with permission from W.B. Saunders Co.)

Fig. 7. Normal

Fig. 6. Location of separation of roots on trunk of tooth aids in determining prognosis. If separation is more coronally located (arrow), more root remains in bone and prognosis is more favorable for remaining tooth structure. (From Abrams L, Trachtenberg DI: Hemisection-Technique and restoration. Dent Clin North Am 18:415, 1974. Reprinted with permission from W.B. Saunders Co.)

Degree (class) ZZ. This class involves horizontal loss of more than 3 mm of periodontal support, but not encompassing the total width of the furcation (Fig. 9). A portion of the bone and periodontium remains intact, but the bone loss is evident on radiographs and the furcation

140

location

of osseous structure

Fig. 8. Class I furcation

involvement.

Fig.

involvement.

9. Class II furcation

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Fig. 10. Class III furcation

Fig. Fig. Fig. Fig.

THE

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12. 13. 14. 15.

OF PROSTHETIC

Working Furcation Furcation Furcation

DENTISTRY

involvement,

end of probe probe probe

furcation entering entering entering

Fig. 11. Class IV furcation

probe with curvature buccal furcation. mesiopalatal furcation. distopalatal furcation.

to enter

furcation

involvement.

area.

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BAlMA

is penetrable clinically with a furcation probe or explorer.4 Degree (class) ZZZ. This class involves a horizontal through-and-through lesion, occluded by gingiva, that allows passage of an instrument from the buccal or lingual direction (Fig. 10). The bone loss is evident on a radiograph.‘, 3x4 Degree (class) IV. This class involves loss of periodontal tissue so the gingival tissues do not occlude the furcation (Fig. 11). The furcation allows unobstructed passage of an instrument, and buccal to lingual communication is observed on visual inspection.4

Diagnosis

of furcation

involvement

The extent of furcal involvement is determined by placing an instrument into the furcation from the buccal, lingual, mesiopalatal, or distopalatal surfaces. The amount of horizontal and vertical tissue loss can be established by direct palpation. Explorers, curettes, or periodontal probes may be used in the diagnosis, but a curved Naber’s Probe (Hu-Freidy, Chicago, Ill.) (Fig. 12) is more suited to examination of the furcation (Fig. 13).

Fabrication of treatment resin denture teeth Richard

The probe allows accessto the horizontal component of the furaction lesion and provides more accurate information concerning the anatomy and extent of the lesion (Figs. 14 and 15). After this information has been recorded, the dentist can develop a treatment plan for periodontal and restorative therapy. The author acknowledges and William J. Pagan.

the contributions

of Drs. Kent G. Palcanis

REFERENCES Abrams L, Trachtenberg DI: Hemisection-Technique and restoration. Dent Clin North Am 18~415, 1974. Gher ME, Vernino AR: Root anatomy: A local factor in inflammatory periodontal disease. Int J Periodont Res Dent 1981. Highfeld JE: Periodontal treatment of multirooted teeth. Australian Dent J 23~91, 1978. Glickman I: Clinical Periodontology, ed 4. Chicago, 1972, WB Saunders Co. Reprint requesb lo: DR. ROBERT F. BAIMA 76 RIDGEWAY AVE. WEST ORANGE, NY 07052

restorations

using acrylic

P. Kinsel, D.D.S.

Foster City, Calif.

E

sthetics becomes particularly important when treatment restorations are to serve the patient for a prolonged period. Possible reasons for extended wear include periodontal splinting, alteration of vertical dimension, occlusal splinting to allow mandibular repositioning, phased treatment, that is, caries control and assessment of oral hygiene, and allowing sufficient time to develop acceptable esthetics. Several methods for the fabrication of provisional fixed partial dentures and single crowns have been described.ls6 Satisfactory results can be attained by fabricating the provisional restoration from an impression of a diagnostic wax-up by using a self-curing acrylic resin processed under pressure.5 Improved color stability and acrylic resin density result from heat processing.6 The major disadvantage of esthetics of these methods is the inherent monochromic appearance and high reflectiveness of acrylic resins. Improvements can be realized 142

with custom shading techniques.‘p8 However, the methods are time-consuming, merely mimic surface stains, and lack color stability; that is, the translucency, internal characterizations, and layering of the dentin and enamel are missing. A method is described for using acrylic resin denture teeth to fabricate treatment restorations that have a natural appearance.

TECHNIQUE 1. Make irreversible hydrocolloid impressions of the maxillary and mandibular arches and pour in die stone. Select the appropriate shade by using a Myerson shade guide for Durablend plastic resin denture teeth (Myerson Tooth Corp., Cambridge, Mass.). 2. Mount the die stone diagnostic casts in centric relation by using an arbitrary face-bow on a semiadjustable articulator. AUGUST

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