BIOLOGICAL CONSIDERATION IN FPD Department Of Prosthodontics Dentistry

BIOLOGICAL CONSIDERATION IN FPD Department Of Prosthodontics Dentistry Explorer

INTRODUCTION It deals with the health of the oral tissues like: § § Adjacent teeth Soft tissues Pulp of the tooth being prepared Periodontium Dentistry Explorer

FIXED PARTIAL DENTURE Definition: A partial denture that is cemented to natural teeth or roots which furnish the primary support to the prosthesis. - GPT Dentistry Explorer

STEPS IN THE FABRICATION OF FPD - Diagnosis and treatment planning Tooth preparation Fluid control and soft tissue management Impression making Provisional restoration Lab procedures Finishing and cementation Dentistry Explorer

Diagnosis and treatment planning • History • Oral examination – Evaluation of oral hygiene – Overall caries activity – General periodontal status – Quality and quantity of saliva – Examination of teeth – Examination of edentulous ridge Dentistry Explorer

Treatment planning – Periodontal consideration • Resolves the inflammation • Converts periodontal pocket depth to clinically normal sulcular depth • Establish physiologic gingival architecture • Provide adequate zone for attached gingiva Dentistry Explorer

Treatment planning contd… • Caries management – All actively carious teeth are treated and restored in amalgam before placement of casting Dentistry Explorer

Contd… • Endodontic consideration • The endodontically treated teeth – Restored with conservative tooth preparation and cast restoration – When there is insufficient remaining tooth structure to support an extracoronal restoration coronoradicular stabilization with a post and core is indicated Dentistry Explorer

Basic principles BIOLOGICAL CONSIDERATIONS • Preservation of tooth structure • Preservation of the periodontium MECHANICAL CONSIDERATION • Retention and resistance • Structural durability • Marginal integrity Dentistry Explorer

PRESERVATION OF THE TOOTH STRUCTURE q Muller De Van stated that the perpectual preservation of what remains is more important than the meticulous replacement of what is lost. q Conservation of tooth structure reduces the harmful effect of the pulpal damage. q Tooth structure can be conserved by using partial coverage or full coverage crown. Dentistry Explorer

Contd. . . q. Preparation of teeth with minimum taper and convergence. q. Prepared occlussal surface should follow the anatomic planes to give uniform thickness in the restorations. q. Small diamond points, used with a water-air spray in high-speed handpiece, removes precisely controlled amounts of tooth structure. Dentistry Explorer

PRESERVATION OF PERIODONTIUM Periodontal health is “ sine qua non ”. For ultimate success of the restoration, the finish line should be placed in an area where the margins of the restoration can be finished by the dentist and kept clean by patient. Most preferable finish line: SUPRAGINGIVAL should be placed in a hard enamel. Subgingival margin: periodontitis Dentistry Explorer

VIOLATION OF THE BIOLOGICAL WIDTH • Definition: The dimension of space that the healthy gingival tissue occupy above the alveolar bone. Dentistry Explorer

• Infringement on the biological Width by placement of restoration within its zone results in gingival inflammation, inflammation loss of alveolar crest and pocket formation • Recommened distance between gingival margin and bone crest : 3 mm Dentistry Explorer

Prevention of damage during tooth preparation Adjacent tooth: – Damaged proximal area of adjacent tooth is much more prone to dental caries even though it is carefully reshaped and polished. PREVENTION: 1) By use of metallic matrix band thin tapered bur. Dentistry Explorer

Soft tissue damage • Soft tissue like lip, cheek and tongue can also get damaged during tooth preparation. PREVENTION: Retraction of lip, cheek and tongue by aspirator tube, saliva ejector and mouth mirror. Dentistry Explorer

PULP DAMAGE CAUSE: Dessication of pulp by heat generation of rotatory instrument. PREVENTION By constant cooling effect or water spray. Dentistry Explorer

Gingival retraction • Gingival cord – Gingival recession – If carelessly used, injury to gingival fibers • Electrosurgery – Uncontrolled depth causes bone trauma – Improper angulation causes injury to gingival fibers • Rotary gingival curettage – Gingival recession – Increased bleeding Dentistry Explorer

impression making Marginal fit of a restoration is essential in preventing recurrent caries and gingival Irritation the finish line of the tooth preparation must be reproduced in the impression. Dentistry Explorer

Provisional restorations • Restoration placed during time between the preparation of the tooth and the placement of the final restoration. Dentistry Explorer

Provisional restorations BIOLOGIC REQUIREMENT • Protect pulp • Maintain periodontal health • Provide occlusal compatibility • Maintain tooth position Dentistry Explorer

Protectpulp Must seal and insulate prepared tooth surface from oral environment to prevent sensitivity and further irritation to the pulp Periodontalhealth Must have good marginal fit, proper contour, and a smooth surface to facilitate plaque removal. Occlusal compatibility establish or maintain proper contacts with opposing teeth Dentistry Explorer

Tooth position Inadequate contacts allow supra-eruption and horizontal movement. Dentistry Explorer

FINISHING External surface of a restoration must be smooth and it should create as nearly a perfect uninterrupted transition from restorative material to tooth as possible. Rough surface accumulates plaque that is injurious to health of the periodontal tissues. Dentistry Explorer

CEMENTATION • Intracrevicular margins are checked carefully after cementation for excess cement • Cement material is tolerated by the gingiva but retains plaque as an overhanging margin causes gingival irritation violates the periodontal attachment, and causes bone loss. Dentistry Explorer

CONCLUSION Oral tissue should be healthy before prosthetic procedure begin and should remain healthy after completion of it Dentistry Explorer

Bibliography • • Contemporary fixed prosthodontics , Stephan Rosensteil Fundamentals of Fixed prosthodontics , Herbert T. Shillinberg Text of prosthodontics, Deepak Nallaswamy www. google. com Dentistry Explorer

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