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

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

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

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

.. Limitations of provisional restorations Recent advances in provisionalization Conclusion References.

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

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..

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).

HISTORY. [image] See the source image.

1937 - Heat cured acrylic resin. 1947 - Auto polymerizing acrylic resin.

1960s - Vinyl poly-ethyl methacrylate (Snap and Trim).

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

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.

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.

REQUIREMENTS. [image] See the source image.

BIOLOGIC Pulp protection Periodontal health Occlusal compatibility Tooth position Protect against fracture.

Pulp Protection.. BIOLOGIC REQUIREMENTS. [image].

Periodontal Health. [image].

3. Occlusal Compatibility and Tooth Position.. [image].

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

MECHANICAL REQUIREMENTS. Function.. [image] tjcjm Areas of overo 01 •touring to improve strength.

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

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.

2. Displacement.. For this and for biologic reasons, unlined preformed crowns should be avoided..

ESTHETIC REQUIREMENTS. Color compatibility Translucency Color stability.

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..

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.

CLASSIFICATION. [image] See the source image.

1.DEPENDING ON THE METHOD OF FABRICATION. CUSTOM MADE PROVISIONAL RESTORATION.

2. DEPENDING ON THE MATERIAL AVAILABLE IN PREFORMED CROWNSAVAILABLE.

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.

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).

DEPENDING ON TECHNIQUE OF FABRICATION. INDIRECT TECHNIQUE.

DEPENDING ON LOCATION OF FABRICATION. CHAIR- SIDE FABRICATED.

MATERIALS AND PROCEDURES. [image] See the source image.

Many procedures using a wide variety of materials are available to make satisfactory provisional restorations.

MOLD CAVITY. 1.Forming the external contour of crown or FDP External surface form (ESF) Custom made Prefabricated.

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..

Moldable putty materials are popular because they can be used without a tray and can be easily trimmed to minimum size.

Prefabricated. They can be thought of as ESFs rather than as finished restorations and therefore must be lined with autopolymerizing resin.

Polycarbonate.. [image] See the source image. [image] See the source image.

Cellulose Acetate. [image] See the source image. 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.

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

[image] See the source image. Nickel-chromium shells are used primarily for children with extensively damaged primary teeth.

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

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

Indirect-direct Procedure. In this technique, the indirect component produces a "custom-made preformed ESF" similar to a preformed polycarbonate crown..

PROVISIONAL RESTORATIVE MATERIALS. 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.

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

Currently Available Materials. The materials can be divided into four resin groups.

These materials shrink during polymerization, which causes marginal discrepancy.