Diagnosis and tt planning in FDP-III

Dr Jitendra RaoDept of Prosthodontics

Consideration before FDP tt planning• Deep bite• Supraeruption of teeth• Short clinical crown • Para functional habits• Severe loss of tissues in the edentulous ridge (Ridge defect)

Deep Bite/Traumatic bite• Overbite more than 3mm of anterior teeth often results in

problems in the design and fitting of F.P.Ds• Sign of posterior occlusal collapse, with its accompanying loss

of inter-arch space

Supra-erupted teeth• Overlooked clinically but will often complicate fixed partial

denture design and fabrication• Inter-arch space obliteration• Short axial height of crown/prosthesis How to counter this problem?• Coronoplasty of enamel• Extraction of tooth• Intrusion of crown• Intentional endodontic tt followed by crown

Parafunction habit• Any parafunctional habit like bruxism, clenching of teeth,nail

biting,object biting

• If a parafunctional habit is verified or even strongly suspected, the patient must be counseled regarding the effects of the habit and if necessary

• Treatment for the adverse habit should be instituted

Tilted Molar Abutments

• The over-all objective in molar uprighting is ideal positioning of the molar which will eventually become an abutment tooth for a fixed prosthesis. The ideal position will provide an optimal periodontal environment for the molar

• Removable partial denture with molar uprighting springe – an appliance for uprighting the severely tilted bilateral molar abutment. This design is very cheap and can be planned at any age without hampering masticatory function during the course of treatment.

• Dr Rao et al-J Prosthodontic Research – 57(1):57-61

Cantilever FPDs• A cantilever FPD is one that has an abutment or abutments at

one end only, with the other end of the pontic remaining unattached. This is a potentially destructive design with the lever arm created by the pontic

• Abutment teeth for cantilever FPDs should be evaluated for lengthy roots with a favorable configuration, good crown root

ratios and long clinical crowns.

Canine Replacement FPD/ Canine Rule

MCQ

1.Contraindication of FDP

a.Diabetes mellitis

b.Hypertension

c.Age below 18 yrs

d.Xerostomia

2.Indication for FDP

a. Crowding of tooth

b. Crown lengthening

c .Rotated tooth

d. Endodontically treated teeth

3.Symptoms are considered to be suffering from a TMJ disorder except

a. Facial disfigurementb.Restricted Jaw movementsc.Clickingd. Pain& tenderness

4.Health of the attached gingiva can be best assessed by

a. Measurement on a radiographb.Application of force on tooth

c.Periodontal probe examination on buccal and lingual surface

d.Bleeding on examinations

5. An Intra-oral radiographic examination reveals all EXCEPT a. Remaining bone support b. Width of Periodontal ligament and trauma from occlusion c. Quality of supporting bone, trabecular patterns and reactions to functional changes, proximity to lamina dura d. Bird eye view of the associated tooth and structure6.Consideration for tt in FDP can be possible ina. Edentulous space with no distal abutmentb. Multiple edentulous spacesc. Tipped teeth adjoining edentulous spaced. Tooth having long and divergent root

7.The major biomechanical factors which affect the design of an FPD are:a. Length of edentulous Ridgeb. Pontic designc. Connector designd. The direction of the forces acting on the FPD

8.Ideal crown-root ratio for a tooth to be utilized as a fixed partial denture abutment is 2:3

a. 1:1b. 2:3c. 1:1.75d. 1:1.5

9. Non rigid connector, keyway on -distal contours of a abutment and key on mesial side of the distal pontic are the features of

a. Pier abutments b. Tilted molar abutments c.Cantilever abutment d. Double abutments10.Arcon articulator a. Condylar housing is in lower memberb. Condylar housing is in upper memberc. Have no Condylar housingd. Is fully adjustable articulator11. Hinge axis is a. Transverse axisb. Vertical axisc. Saggital axisd. Coronal axis

12.Jepsen’s rule is applicable fora. Pontic selectionb. Abutment selectionc. Crown root ratio for FPDd. Root surface area of abutment13.Tilted molar abutment is contraindicated for FPD

a. > 150 b. < 200

c. 200 - 250 d. >250

14.Reason for not replacing the maxillary canine through FPD is all EXCEPTa. Canine is outside the inter-abutment axis b. Longest root in the archc. LI is weakest in ant and Ist PM is weakest in post regiond. Prone for pulp exposure

15. Tooth having minimum root surface area

a. Maxillary CI b. Mandibular CIc. Mandibular LId. Maxillary LI

Books

• Rosensteil• Shillingburg

Key for MCQ1.c2.d3.a4.c5.d6.d7.d8.b9.a10.b11.a12.b13.d14.d15.c