Dr Priyam Javed

1. GOODMORNING….

2. PREPARATION OF
PERIODONTALLY
WEAKENED TEETH
Subtitle
FATEEMA PRIYAM
2ND YR PG

3. INTRODUCTION
• Teeth that have been saved by periodontal therapy often need cast
restorations.
• Can occur-caries,previous damage or teeth may have to be splinted
together to improve stability
• These teeth-may be needed as abutments for prostheses replacing
missing teeth.
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4. Preparation finish line
• If improperly designed????
• Proximity of the preparation finish line to the furcations can
necessitate even further modification…
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5. Location
• Optimal finish line-on the enamel away from the gingival sulcus.
• Shoulder-poor choice if margin is to be placed on the root surface
• Constricted smaller diameter of the root-axial reduction be extended into
the tooth –pulp threatening depth to obtain 1mm wide shoulder.
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7. • Also weakens the natural structural durability
• Greater potential for stress concentration –?????
• CHAMFER finish line is preferred on the facial surface in this
apical position –???
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9. FURCATION FLUTES
• It is where the root trunk divides into 2 or 3 roots.
• The designs of both the tooth preparations and crowns must be
different from those customarily made.
• The axial contours of crowns placed on teeth whose furcation
flutes are intercepted by preparation finish lines-reflect the
concavity
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10. • Crown should recreate the contours of the furcation flute
• Mesial and distal concavities –softened and blended into axial
surfaces of crown-minimize difficulty in cleaning inaccessible
areas
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12. Root resection
• Root is removed-irrespective of what is done with the crown
• Root amputation-removal of root without touching the crown
• Hemisection-tooth is separated through the crown and the
furcation
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13. • Bambel D et al presented a case report of a patient who presented with pain
and swelling in the upper right first molar with h/o RCT.A deep periodontal
pocket was associated with buccal aspect of mesio-buccal root and a root
resection was done.
• They concluded that root resection is useful when involved tooth has
divergent roots and adequate distance between separation point remaining
roots and floor of pulp chamber.
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14. Indications
• To maintain good hygiene and plaque control
• Severe vertical bone loss
• Severe loss of bone or attachment
• When furcation entrance is that narrow –instrument
inaccessibility-resection creates an area that can be adequately
cleaned.
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15. • Salvage teeth with endodontic problems-perforations,irretrievable
broken instruments etc
• Fractured root,untreatable caries
• Periodontal strategic extraction
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16. Contraindications
• Fused roots or those that approximate other roots of the same
tooth
• If the furcation is too far apical???
• Maxillary first premolars???
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17. • If excessive alveolar support has been lost uniformly all around
the roots, nothing is gained by removing a root.
• If a root that is to be kept cannot be successfully treated
endodontically
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18. Capacity of resected root
• Teeth that have been resected –abutment teeth for FPD,splints or
vertical stops
• However their load bearing capacity has been lessened-diminished
attachment area.
• As level of bone is lowered by periodontal disease-periodontal
attachment decreases.
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19. Resection technique
• Complete endodontic treatment before removing the root.
• Often its not possible to evaluate the furcation without completely
reflecting the flap
• Begin resection with a long ,thin diamond to cut through the vault
of the furcation.
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20. • Remove all traces of the resected root at the time of surgery.
• Do not leave any vestigial remnants of the furcation vault.??
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21. Tooth preparation and crown
configuration
• When a root has been removed from the tooth both the tooth
preparation and the contours of the crown will be different
because of the altered tooth shape.
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22. Maxillary distofacial root
• The distal furcation is susceptible to frequent periodontal
involvement because of the proximity of the divergent distofacial
root to the nearby second molar and its inaccessibility to the
patient.
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23. • Since its small-occlusal outline resembles a lamb chop –occlusal
direction
• Distofacial embrasure is larger than usual ,enabling patient to
keep the area clean.
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24. • Distofacial cusp smaller-does not create any esthetic problems-
hidden by the mesiofacial cusp
• Proximal contact is contoured to its normal faciolingual size
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25. • Imp-contours of distofacial cusp apical to the contact area –
definitive concave shape.
• Hence-crown contours will be aligned to the root configuration in
that critical area,preventing impingement on the gingiva
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27. Maxillary mesiofacial root
• Loss-greater loss of support than that of distofacial root
• Accounts for 25-36% of first molar root area.
• If removed-occlusal outline will have a more triangular
configuration-greater faciolingual dimension
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28. • Finish line will extend-apically past the pulp chamber
• Concavity gingivofacial to the proximal contact on the mesial
surface of the crown.
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29. • OBJECTIVES
• Long-term retention of teeth and especially molars in function is the ultimate
goal of periodontal therapy. Root-resective therapy is a treatment option for
molars with advanced furcation involvement, which has been questioned
because of the heterogenous success rates published in literature.
This study aimed to evaluate long-term results of root-resective treatment
over a period of up to 30 years.
• METHODS:
• In this retrospective cohort, 90 root-resected molars in 69 patients were
examined for 4-30 years (14.7 ± 6.8 years). The complete treatment sequence
was performed by one of the authors in a general dental practice.
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30. • RESULTS:
• Overall cumulative survival rate was 90.6% after 10 years, but then
decreased considerably. Molars after root resection had a median survival
time of 20 years. The incidence of endodontic complications leading to tooth
extraction was only 26.7%, 50% were lost due to periodontal problems, and
16.7% because of caries. Mandibular molars had a significantly lower
relative risk of loss than molars in the maxilla .
• Mandibular molars showed a survival probability of almost 80% even
20 years after root resection.
• CONCLUSION:
• Root-resective therapy is a predictable treatment option, when care is
administered at each phase of therapy..
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J Clin Periodontol

31. Maxillary palatal root
• When removed-palatal surface of the preparation will be flat –
resembling the configuration of a remaining root stump.
• The central groove is aligned with those of the occlusal surfaces
of adjacent teeth.
• The lingual cusps will be quite small
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33. • The presence of these cusps –area inaccessible to hygiene
maintenance-linguogingival segment of the crown.
• This will also create a severe torquing moment on the tooth –
either tip the tooth lingually or fracture the tooth preparation
under the crown
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35. Maxillary facial roots
• Here only the palatal root remains
• Preparation of the tooth overlying this root will result –oval or
circular configuration depending on the shape of the root itself.
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36. • Resulting crown should occlude with its mandibular counterpart
in such a way that occlusal forces cannot be directed facially.
• This will place it in a near reverse occlusal or cross-bite
relationship
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37. • Harwell E et al conducted a study in which maxillary molars were treated
with root resections were reviewed from 34 patients in a series of 5 patient
histories.
• All teeth were used as abutments for Rpd/Fpd.6-20 yr follow up were
reported.Approximately 70% of all teeth treated by root resection remained
for more than 4 years or longer.
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Int J Prosthodont.1998;1:87-92

38. Mandibular hemisection
• Frequently one root is removed while the other root remains.
• Saving the mesial segment would be desirable –if molar in question were the last
tooth in the arch and the opposing teeth did not extend very far distal to the
mandibular first molar.
• Distal root could be used as an abutment for a short span fixed partial denture
replacing the mesial root.
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40. • Occasionally, one root may be used as the distal abutment for a
longer span fixed partial denture, replacing an entire molar.
• This must be viewed as a high risk prosthesis,since the remaining
distal root has slightly less than one-third of the alveolar support
of the intact tooth with normal bone.
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42. • Zafiropaulos et al stated that success rates for both periodontal and implant
therapy are often dependent on site and tooth type.
• For periodontally involved mandibular molars decision to hemisect or place
an implant is often complicated.
• Within limitations of the study,results indicated that in periodontitis
patients,hemisected mandibular molars were more prone to complications
than implants.
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J Oral Implantol.2009;35(2),52-62

43. • Park JB et al reported the long-term effects of hemisection of teeth with
questionable prognosis.
• The outcome in a 34-year-old male patient with mobile teeth in the lower
left posterior area is reported.
• Removal of the mesial root of the mandibular first molar and the
distal root of the mandibular second molar was done. The final restoration
was performed after using a provisional restoration for three months.
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44. J Int Acad Periodontol. 2009 Jul;11(3):214-9
• The final restoration functioned well without detectable mobility or any
noticeable bone loss for up to seven years.
• Within the limits of this report, the hemisection of molars with questionable
prognosis can maintain the teeth without detectable bone loss for a long-term
period, provided that the patient has optimal oral hygiene.
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45. BICUSPIDIZATION
• If an effort is made to save both roots of the molar following the
resection, the process is described as ‘bicuspidization’
• If both roots are maintained , it is important that they be separated
from each other to allow normal gingival embrasure spaces.
• Sometimes the roots are distinctly separate, angling out of the
furcation and providing the separation naturally.
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48. • However,if they are not naturally separated,some measure must
be taken to accomplish it .
• Separation may be accomplished by moving the roots apart
orthodontically,or it may be accomplished with inter-radicular
shoulders on the crown preparations on the separated roots.
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50. Skyfurcation
• It may be desirable to separate the roots of a maxillary molar
without removing a root-roots have to be long,well supported by
bone and distinctly separate.
• Roots-cut apart-then joined by a crown-in reality is an inter-
radicular splint with concave connectors from one root to the
other.
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51. • Improves access to furcation and protects caries prone area.
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53. • The present investigation was designed to evaluate the long-term effect
of root-resective therapy in the treatment of furcation-involved molars. The
patient sample included 72 patients, 21-62 years of age, who presented
periodontal lesions in the posteriors segments of the mouth including
furcation involvement of various degrees)
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54. • After an initial examination, each patient was subjected to a series of full-
mouth scaling and root planning and recalled after 3 months.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).
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55. • 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.
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56. • 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.
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J Clin Periodontol. 1998 Mar;25(3):209-14.

57. • Erlich et al reported 87% success rate in furcation involved teeth
treated by root resection after 10 to 18 years.
• Ross and Thompson on the other hand published a similar success
rate-88% for furcation involved molars that were treated
conservatively without root resection.
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SUMMARY

58. • Hamp and associates reported being able to maintain all 87 of the
resected teeth in their study over a 5 year period.
• Mandibular roots are more likely to fail than maxillary
roots….reason???
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59. • Derks H,Westheide D.Retention of molars after root-resective therapy: a
retrospective evaluation of up to 30 year.Clin Oral Investig 2018
Apr;22(3):1327-15.
• Carnavale G, di Febo G. Long-term effects of root-resective therapy in
furcation-involved molars. A 10-year longitudinal study. J Clin
Periodontol 1998 Mar;25(3):209-14
• Park J B. Hemisection of teeth with questionable prognosis. Report of a case
with seven-year results.J Int Acad Periodont 2009 Jul;11(3):214-9.
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JOURNAL REFERENCES

60. • Zafiropoulos G,Kasaj A.Mandibular molar root resection versus implant
therapy:A retrospective non randomized study.J Oral
Implantol.2009;35(2),52-62
• Harwell E W.Vital root resection.A conservative procedure for abutment
teeth.Int J Prosthodont.1998;1:87-92
• Ehrlich J,Root resection and separation of multirooted teeth:A 10 year follow
up study.Quintessence Int 1989:34
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61. TEXTBOOK REFERENCES
• Shillingburg T,Hobo S.Fundamentals of Fixed Prosthodontics.3rd
Edition.Quitessence Publication.
• Rosenstiel SF,Land MF.Contemporary fixed prosthodontics.4th
Edition,2014,Elsevier.
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