BDS Year 1 Regular batch Academic Year 2023-2024 Subject: Dental Materials Topic: PROVISIONAL RESTORATION

[Audio] BDS Year 1 Regular batch Academic Year 2023-2024 Subject: Dental Materials Topic: PROVISIONAL RESTORATION Dr. Vaibhavi Hathi Senior Lecturer Dept. of Prosthodontics and Crown & Bridge.

[Audio] . [image] Life is full temporary situations, ultimately ending in a permanent solution. Rodney Dangerfield.

[Audio] CONTENTS Synonyms Introductcion Definitions History Requirements for fixed provisional restorations Types of provisional restorations Various techniques of fabrication.

[Audio] . Limitations of provisional restorations Recent advances in provisionalization Conclusion References.

[Audio] SYNONYMS Provisional restoration Treatment restoration (Temporization) Interim prosthesis • Provisional prosthesis The word provisional means established for the time being pending a permanent arrangement.

[Audio] INTRODUCTION Provisional crowns or fixed partial dentures are essential to prosthodontic therapy. Though a definitive restoration may be placed as quickly as 2 weeks after tooth preparation..

[Audio] DEFINITION . A fixed or removable prosthesis designed to enhance esthetics, stabilization and function for a limited period of time after which it is to be replaced by definitive prosthesis.(GPT-9).

[Audio] HISTORY. HISTORY. [image] See the source image.

[Audio] 1937 ---- Heat cured acrylic resin 1947 ---- Auto polymerizing acrylic resin 1952 ---- Brotman introduced prefabricated aluminum or celluloid crown form 1959 ---- Amsterdam et al suggested use of copper band splint.

[Audio] 1960s ---- Vinyl poly-ethyl methacrylate (Snap and Trim) 1969 ---- Ethyl imine derivatives ( Suctan) 1972 -technique for a modified “shell” type temporary acrylic resin fixed partial denture 1973 ---- Charles et al described the use of polycarbonate resin.

[Audio] 1980 ---- Composite (Protemp, Visio Gem and Triad) 1983 -Technique that use silicone putty impression material in provisional restoration fabrication..

[Audio] Rationale for Provisional Restoration (Fredrick and Krug) Protect pulpal tissue and sedate prepared abutments 2. Protect teeth from dental caries 3. Provide comfort and function 4. Evaluate parallelism of abutments 5. Provide method for immediately replacing missing teeth 6. Prevent migration of abutments 7. Improve esthetics.

[Audio] 8. Evaluate and reinforce the patient’s oral home care 9. Provide a matrix for the retention of periodontal surgical dressings 10. Stabilize mobile teeth 11.Provide anchorage for orthodontic brackets during tooth movement 12. Aid in developing and evaluating an occlusal 13. Allow evaluation of vertical dimension, phonetics, and masticatory function 14. Assist in determining the prognosis of questionable abutments during prosthodontic treatment planning.

[Audio] REQUIREMENTS. REQUIREMENTS. [image] See the source image.

[Audio] BIOLOGIC Pulp protection Periodontal health Occlusal compatibility Tooth position Protect against fracture MECHANICAL Resist Functional load Resist Removal forces Inter-abutment alingment ESTHETIC Contourable Colour stability Translucent Texture.

[Audio] BIOLOGIC REQUIREMENTS Pulp Protection.. Pulp Protection..

[Audio] Periodontal Health. Periodontal Health. [image].

[Audio] 3. Occlusal Compatibility and Tooth Position. Maintain proper contacts with adjacent and opposing teeth A missing proximal contact allows tooth migration.

[Audio] 4. Prevention of Enamel Fracture Fracture of a tooth after the impression phase delays treatment and jeopardizes restorability. proximal contour..

[Audio] MECHANICAL REQUIREMENTS Function.. MECHANICAL REQUIREMENTS.

[Audio] In this mesiodistal section, an overcontoured connector crowds the gingiva. Pressure ischemia and poor access for plaque removal promote gingivitis..

[Audio] Need of high-strength provisionals A long span posterior fpd Prolonged treatment plan Avoid excess forces Above average masticatory muscle strength History of frequent breakage.

[Audio] 2. Displacement. For this and for biologic reasons, unlined preformed crowns should be avoided. 3. Removal for Reuse. Provisional restorations often need to be reused and therefore should not be damaged when removed from the teeth..

[Audio] ESTHETIC REQUIREMENTS Color compatibility Translucency Color stability.

[Audio] Proper contours The emergence profile must be the same as the original tooth to facilitate plaque removal. Embrasure areas must be contoured to allow for the interdental papilla. The pontic must be contoured so that it is as self cleansing as possible..

[Audio] In this improperly contoured fixed partial denture, There is not enough embrasure space. The dental papilla are impinged upon and signs of gingival inflammation are present.

[Audio] CLASSIFICATION. CLASSIFICATION. [image] See the source image.

[Audio] 1.DEPENDING ON THE METHOD OF FABRICATION CUSTOM MADE PROVISIONAL RESTORATION PREFABRICATED PROVISIONAL RESTORATION.

[Audio] 2. DEPENDING ON THE MATERIAL AVAILABLE IN PREFORMED CROWNSAVAILABLE Polycarbonate Cellulose acetate Aluminium and tin-silver Nickel-chromium.

[Audio] DEPENDING ON THE TYPE OF MATERIAL USED Resin based provisional restoration Cellulose acetate Polycarbonate resin Poly-methyl methacrylate Poly-ethyl methacrylate Microfilled composite Urethane dimethacrylate Bis -acryl composite Metal provisional restoration Aluminium Nickel-chromium Tin-silver.

[Audio] DEPENDING ON THE DURATION OF USE -SHORT TERM -for few days (upto 2 weeks) ( e.g. ---- Polycarbonate or aluminum crowns ) -MEDIUM TERM ---- for few weeks ( > 2 weeks) ( e.g. ---- resin based provisionals) -LONG TERM ---- for months ( e.g. ---- mostly cast metal crowns).

[Audio] DEPENDING ON TECHNIQUE OF FABRICATION INDIRECT TECHNIQUE DIRECT-INDIRECT TECHNIQUE DIRECT TECHNIQUE.

[Audio] DEPENDING ON LOCATION OF FABRICATION CHAIR- SIDE FABRICATED LABORATORY FABRICATED.

[Audio] MATERIALS AND PROCEDURES. MATERIALS AND PROCEDURES.

[Audio] Many procedures using a wide variety of materials are available to make satisfactory provisional restorations An alginate impression vacuum-formed acetate sheet Baseplate wax impression A polycarbonate preformed shell Three-unit FPD shell A silicone putty impression.

[Audio] MOLD CAVITY Created by two correlated parts:- 1.Forming the external contour of crown or FDP External surface form (ESF) Custom made Prefabricated 2. Forming the prepared tooth surfaces and edentulous ridge area -Tissue surface form ( TSF) Direct technique Indirect technique Indirect-direct, results from the sequential application of these two forms.

[Audio] EXTERNAL SURFACE FORM CUSTOM MADE A custom ESF is a negative reproduction of either the patient's teeth before preparation or a modified diagnostic cast. It may be obtained directly with any impression material..

[Audio] Moldable putty materials are popular because they can be used without a tray and can be easily trimmed to minimum size A custom ESF can be produced from thermoplastic sheets, which are heated and adapted to a stone cast with vacuum or air pressure while the material is still pliable.

[Audio] Prefabricated They can be thought of as ESFs rather than as finished restorations and therefore must be lined with autopolymerizing resin Materials from which preformed ESFs are made include polycarbonate, cellulose acetate, aluminum, tin-silver, and nickel-chromium. These are available in a variety of tooth types and sizes.

[Audio] Polycarbonate. Polycarbonate has the most natural appearance of all the preformed materials.

[Audio] Cellulose Acetate Cellulose acetate is a thin (02 to 0.3 mm) transparent material available in all tooth types and a range of sizes.Shades are entirely dependent on the autopolymerizing resin.

[Audio] Aluminum and Tin-silver Aluminum and tin-silver are suitable for posterior teeth..

[Audio] Nickel-chromium Nickel-chromium shells are used primarily for children with extensively damaged primary teeth.

[Audio] TISSUE SURFACE FORM Indirect Procedure.. TISSUE SURFACE FORM.

[Audio] Direct Procedure. Direct Procedure. [image].

[Audio] Indirect-direct Procedure In this technique, the indirect component produces a "custom-made preformed ESF" similar to a preformed polycarbonate crown. Another method of creating the shell eliminates the need for an indirect TSF.

[Audio] PROVISIONAL RESTORATIVE MATERIALS Ideal Properties An ideal provisional material has the following characteristics Convenient handling-adequate working time, easy moldability, rapid setting time Biocompatibility-nontoxic, nonallergenic, nonexothermic • Dimensional stability during solidification Ease of contouring and polishing Adequate strength and abrasion resistance.

[Audio] Good appearance-translucent, color controllable, color stable Good patient acceptance-nonirritating, odorless Ease of adding to or repairing Chemical compatibility with provisional luting agents.

[Audio] Currently Available Materials The materials can be divided into four resin groups Poly(methyl methacrylate) Poly(R' methacrylate) Microfilled composite Light-cured.

[Audio] These materials shrink during polymerization, which causes marginal discrepancy.