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Hemisection as an AlternativeTreatment for VerticallyFractured
Mandibular Molars
Gregori M Kurtzman,DDS, MAGD, FACDAssistant Clinical
ProfessorDepartment of Endodontics,Prosthetics, and
OperativeDerrtistryUniversity of MarylandBaltimore College of
DentalSurgeryBaltimore, MD
Lee H Silverstein, DDS,MS, FACDAssociate Clinical Professor
Peter C Shatz, DDSAssistant Clinical Professor
Department of PeriodontologyMedical College of Georgia,School of
DentistryAugusta, Ceorgia
he treatment of severe furcalbone loss may require theremoval of
a portion of the
anatomic crown and its associated rootor resection of only 1
root from a mul-tirooted tooth.r This type of surgicaltherapy
enables clinicians to betteraccess the remaining tooth structure
forperiodontal and subsequent prosthetictherapy. The morphology of
the neces-sary tooth preparation for root resec-tion, in this case
hemisection, requiresthat the final anatomic form must nothamper
the patient's ability to accom-plish optimal long-term
maintenanceof the affected area.'
Prosthetic therapy and restorativesequencing is often
complicated whenperiodontal attachment loss, caries, ortooth
fracture involves the furcation areaof the multirooted molar.
Although suchinvolvement invariably diminishes thelong-term
prognosis of the affected teeth,extraction is not necesarily an
option.Hemisection periodontal therapy, whichinvolves removal of
the involved rootand its asociated crown portion, is oneof several
treatment modalities that canbe used in such cases.
It is important for dentists to knowthe necessary
indications/contraindica-tions, surgical techniques, and
prostheticmanagement for successful hemisectionperiodontal therapy.
Hemisection thera-py is a predictable treatment modalitywith a high
degree of success if some
basic considerations are followed.la Forexample, in the case
presented, fractureof the mandibular molar root may notdoom the
remaining unaffected portionof the tooth to extraction. When
thehealth of the other root is sound, hemi-section may be used to
provide a premo-lar-shaped restoration.
Case PresentationA 40-year-old man presented with
the complaint of a rough area on hislower right first molar.
Examinationrevealed a vertical fracture of the distalroot. The
cause of the fracture wasunknown. The tooth had undergoneprior
endodontic therapy and wasasymptomatic. There was no evidence ofa
crown or a post and core. Radio-graphically, it was evident that
the distalroot had a fracture separating the rootinto 2 parts
(Figure l). A radiolucentlesion was noted extending coronallyfrom
the apical tip to the furcation. Sur-prisingly, neither tooth
portion demon-strated any mobility (Figure 2). Themesial root
lacked pathology and testednegative for percussion. The only
othermandibular teeth missing were the rightsecond molar and third
molars bilateral-ly. Periodontal health was normal andno other
restorations or decay were pre-sent on the remaining teeth.
Tieatment options were discussedand it was decided to save and
restorethe mesial root of tooth No. 30 because
Abstract: Hemisection of mandibular molars may be a viable
treatment optionwhen vertical root fracture has occurred and the
other root is healthy. This arti-cle discusses a case that presents
the techniques involved in hemisection andrestoration of the
remaining tooth.
Compendium / February 2006 Vol. 27. No.2
-
Figure 1-lnitial presentation of tooth No, 30 demonstrating
ver-tical root fracture and pathology ass0ciated with the distal
root.
of financial considerations. When financesallow, future
treatment will include placementof an implant distal to the
restored mesial rootand restoration with a fixed single crown.
The patient returned 8 months after theinitial consultation to
initiate treatment;finances had improved and he now had insur-ance
benefits. Clinically and radiographically,no changes had occurred
and the patient indi-cated that the area remained symptom-free.
Local anesthetic was applied via a mentalblock and periodontal
ligament injection with4% septocaine with 1:100,000 epinephrine.
Acoarse tapered diamond was used in a highspeed handpiece with
water to place a cut fromthe buccal to the lingual through the
furcation(Figure 3). Periotomes were used to luxate themost distal
root fragment by gentle apicallydirected force into the periodontal
ligamentspace. The segment was then removed with arongeur. The
periotomes were then introducedinto the cut placed at the
furcation, and theremaining root was moved distally andremoved with
the rongeur (Figures 4 and 5).The diamond was used to remove the
lip at thefurcation on the mesial root and elirninate anyundercut
that might trap plaque. The old com-posite core was removed, and
the orifices forthe mesial-buccal and mesial-lingual canalswere
identified. A bipolar unit was used totrough the sulcus around the
remaining root toexpose more root structure and improve the
fer-rule affect for the future crown. Bleeding on themesial papilla
was additionally controlled withthe bipolar unit (Figure 6).
Peeso burs were used to prepare a postspace in both canals to a
diameter of 1.25 mmand a depth of 10 mm. An adhesive was
applied
Vol. 27, No. 2
Figure 2*Clinical presentation demonstrating the vertical
rootfracture of the distal root.
Figure 3-Hemisection cut made with a diamond through
thefurcation.
Figure 4-Distal root fragments and old composite on mesialroot
removed. Canal orifaces were identified on the mesial-buc-cal and
mesial-lingual canals. Note the osseous exostosis on thebuccal
olate,
Compendium i February 2006 863
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Figure S-Distal root fragments after extraction.
Figure 7-Posts were luted into the 2 mesial canals with a
dual-cure resin cement. Blue dual-cure resin core material was
inject-ed in and around the posts to create a core.
into each post preparation and all exposeddentin. Excess
adhesive was removed withpaper points. A dual-cure resin cement
wasinjected into the post spaces and a post wasinserted to length.
Excess luting agent wasremoved from around the posts by
applicationof air with the air/water syringe. A contrastingcolor
dual-cure resin core material was injectedaround the posts and
built up coronally (Figure7). After setting of the materials, the
excesslength of fiber post was reduced and the corewas shaped,
keeping the restoration out ofocclusion (Figures 8 and 9).
The patient returned after 4 weeks of post-surgical healing. The
soft tissue had healed atthe distal root, and the mesial root
remainedasymptomatic. Preparation of the mesial rootwas made to
accept a porcelain-fused-to-metal(PFM) crown. The contrasting color
of thecore material assisted in ensuring adequate fer-
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Compendium / February 2006
Figure 6-Clinical site demonstrating the soft tissue at the
distalroot, A bipolar unit was used t0 expose more of the mesial
rootand control a spot of hemorrhagic tissue on the mesial
papilla.Canals prepared for 1.25 mm fiber posts.
Figure 8-The core was shaped and excess post length
wasadjusted.
rule in the preparation. A nontraumatic retrac-tion materialu
was injected into the sulcus, anda Comprecapb was placed over the
preparation.The patient was instructed to bite into theComprecap,
and occlusion was maintained for5 minutes to provide better capture
of the mar-gins. Correct-Plus, a light-body po$vinyl silox-anec was
subsequently injected around thepreparation, and a full-arch
impression trayfilled with medium-body polyvinyl siloxanecwas
inserted. An opposing full-arch impressionand bite were taken. A
temporary crown wasfabricated and luted with temporary cement.
The patient returned several weeks later forcompletion of
treatment on tooth No. 30. Thetemporary crown was removed and the
finalrestoration tried in. Occlusion was checked andthe PFM crown
was luted with a dual-cure resincement (Figures 10 and 11).
The full-coverage crown should preventany further fracture of
the tooth that remains.Had the tooth originally been crowned, it
maynot have fractured.
864 Vol.27, No.2
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Figure 9-Radiograph taken after hemisection and
posUcorefabrication in the mesial root.
Figure 10-Radiograph taken 1 month after surgery. Bone fill
isdemonstrated in the distal root space and lack of apical
patholo-gy on the mesial root.
Figure 11-Completed porcelain-fused-to-metal crown restoringthe
tooth to function,
DiscussionIn situations when resection periodontal
therapy can be predicted, initiation of conven-tional endodontic
treatment before therapy sim-plifies the surgical procedure. This
is often thecase because tooth preparation can invade thepulp
chamber andjeopardize control ofthe coro-nal seal ofthe endodontic
acces opening, com-plicating the completion of endodontic
therapy.
When choosing to perform a hemisectionprocedure, consideration
should be given to themorpholory, clinical length, and shape of
theroots of a multirooted tooth. The divergence of
Vol.27, No. 2
the roots is an important indication. Affectedteeth with roots
spread apart facilitate the clin-ician's ability to perform a root
resection; teethwith closely approximated or fused roots shouldnot
receive hemisection therapy.
Conversely, the contraindications to per-forming hemisection
periodontal therapyinclude a nonphysiologic postsurgical
architec-ture that would preclude good home care, or aninadequate
amount of alveolar bone remainingto support the existing root
structure. Also, ifpulp cannot be treated adequately in the
canalsystem of the roots to be retained or this seg-ment of the
tooth is nonrestorable, hemisec-tion therapy should not be
undertaken.s
After resection therapy, the restorativerehabilitation begins.
The current prostheticguidelines for rehabilitation include a
conflu-ence of the root and the prosthetic crown con-tours. In
addition. the axial tooth contours ofthe restored resected teeth
should have a phys-iologic contour, which implies that the
restora-tion emerges from the root with a zero degreeemergence
profile. These transgingival areasshould therefore exhibit a flat
prosthetic con-tour at the gingival margin, producing a
morehygienic, less plaque retentive region whencompared with a
tooth restored with a cervicalbulge at the gingival portion of the
prosthesis.G
ConclusionThe removal of a root and the overlaying
anatomic crown is refered to as a hemisection.Hemisection of
either a maxillarv or mandibularmolar is often a means of retaining
teeth neededfor restorative abutments or occlusal support.This
treatment can produce predictable resultsas long as proper
diagnostic, endodontic, surgi-cal, and prosthetic procedures are
performed.
Referencesl. Glickman T. Clinical Periodontologlr. lst ed.
Philadelphia,
PA: WB Saunders; 1953.Silventein LH, Moskowitz ME, Kurtzman D,
Shatz PC.Prosthetic considerations with periodontal root
resectivetherapy, Part 2. Hemisections . Dent Today, I 999; I
8:86-89.Hernpton T Leone C. A review of root reseotive therapyas a
treatment option for maxillary molars, J Am DentAssoc. 1997; I
28:449-455.Cohen E. Atlas of Cosmetic and Reconstructive
PeriodontalSurgery. 2nd ed. Philadelphia, PA: Lea & Febiger;
1994.Appleton IE. Restoration of resected teeth. J Prostfi
Dent.1980;44:1 50- I 53.Rosenberg M, Keough B, Kay H, et al.
Periodontal andProsthetic Management for Advanced Cases. Chicago,
IL:Quintesence Publishing Co; 1988.
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