Operative Dentistry

Purposes of Operative Dentistry Proper diagnosis is vital for treatment planning. DIAGNOSIS: To prevent any recurrence of the causative disease and their defect. PREVENTION: Preventing further loss of tooth structure by stabilizing an active disease process. INTERCEPTION: Preservation of the vitality and periodontal support of remaining tooth structure. PRESERVATION: RESTORATION: Includes restoring form, function, phonetics, and esthetics.

Indication of Operative Dentistry Caries; Malformed, discolored, or fractured teeth; Restoration replacement.

Program of Operative Treatment Patient assessment Examination and diagnosis Treatment planning Pain control: local anesthetic Isolation of the operating field

Program of Operative Treatment Cavity preparation Matrix application Preparation of materials Insertion and carving of materials Finishing and Polishing

Cavity Preparation The mechanical alteration of a defective, injured, or diseased tooth in order to best receive a restorative material which will re-establish a healthy state for the tooth including esthetic corrections where indicated, along with normal form and function.

Cavity Structure walls angles cavity

Classification of cavity Class II Class III Class IV Class V Class VI —G.V.Black in 1908

Cavity Simple cavity: only one tooth surface is involved. Compound cavity: two surfaces are involved. Complex cavity: three or more surfaces are involved.

Class 1 Class 6 Class 1 Class 4 Class 3 Class 2 Class 2 Class 5

Stages and Steps in Cavity Preparation Initial cavity preparation stage Final cavity preparation stage

Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

Outline Form and Initial Depth Ⅰ Definition: placing the cavity margins in the positions they will occupy in the final preparation; preparing an initial depth of 0.2~0.8 mm pulpally of the dentinoenamel junction position or normal root surface position.

Maxillary Class Ⅰ outline form

Mandibular Class Ⅰ outline form

Maxillary Class Ⅱ outline form

Mandibular Class Ⅱ outline form

Common Error

Outline Form and Initial Depth Ⅱ Principles: without any exception all friable and/or weakened enamel should be removed all faults should be included all margins should be placed in a position to afford good finishing of the margins of the restoration.

Outline Form and Initial Depth Ⅲ Features: preserving cuspal strength preserving marginal ridge strength minimizing facio-lingual extension using enameloplasty connecting two close faults or cavities restricting the depth of the preparation into dentin.

Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

Primary Resistance Form Ⅰ Definition: The shape and placement of the cavity walls that best enable both the restoration and the tooth to withstand, without fracture, masticatory forces delivered principally in the long axis of the the tooth.

Primary Resistance Form Ⅱ Principles: To utilize the box shape with a relatively flat floor to resist occlusal loading by virtue of being at right angles to mastication force; To restrict the extension of the external walls (keep as small as possible) to allow strong cusp and ridge areas to remain with sufficient dentin support;

Primary Resistance Form Ⅲ Principles: To have a slight rounding of internal line angles to reduce stress concentration in tooth structure; To provide enough thickness of restorative material to prevent its fracture under load.

Primary Resistance Form Ⅳ Feature: Box shape Relatively flat floors Inclusion of weakened tooth structure Preservation of cusps and marginal ridges Rounded internal line angles Adequate thickness of restorative materials Reduction of cusps for capping if indicated

Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

Primary Retention Form Ⅰ Definition: The shape or form of the prepared cavity that resists displacement or removal of the restoration from tipping or lifting forces. In many respects retention and resistance form are accomplished in the same cutting procedure.

Primary Retention Form Ⅱ Principles: depending on the materials Amalgam restoration: developing external cavity walls that converge occlusally and dovetail design

The devotail design provide retention form to the occlusal portion of the cavity. The occlusal convergence of the walls offers retention in the proximal portion of the cavity against displacement occlusally.

Primary Retention Form Ⅲ Principles: depending on the materials Composite restoration: a mechanical bond between the material and conditioned, prepared tooth structure.

Initial cavity preparation stage Step 1 Outline form and initial depth Step 2 Primary resistance form Step 3 Primary retention form Step 4 Convenience form

Convenience Form Ⅰ Conception: The shape or form of the cavity that provides for adequate observation, accessibility, and ease of operation in preparing and restoring the cavity.

Convenience Form Ⅱ Principles: Allow access for caries removal Allow access for restoration placement Allow access to margins for finishing, evaluation and cleaning

Convenience Form

Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

Removal of any remaining infected dentin if indicated Definition: The elimination of any infected carious tooth structure or faulty restorative material left in the tooth after initial cavity preparation.

Removal of dentinal caries using round burs and spoon excavators A: use of a round carbide bur, with air coolant and slow speed. B: use of spoon excavators. Removal of dentinal caries using round burs and spoon excavators

Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

Pulp protection Using liners or bases to protect the pulp or to aid pulpal recovery or both.

Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

Secondary resistance and retention forms Ⅰ Most compound and complex cavity preparations require additional resistance and retention form. The exception being those preparations that are very conservative.

Secondary resistance and retention forms Ⅱ Mechanical forms Cavity wall conditioning form

Mechnical form: Proximal locks Proximal slots

Proximal locks

Slot on gingival wall

Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Finishing external walls Step 9 Final procedures

Finishing the external walls Ⅰ Definition: is the further development of a specific cavosurface design and degree of smoothness that produces the maximum effectiveness of the restorative material being used.

Finishing the external walls Ⅱ Objectives: To create the best marginal seal possible between the restorative material and tooth structure; To afford a smooth marginal junction; To provide maximum strength of both the tooth and the restorative material at and near the margin.

The strongest enamel margin is that margin which is composed of full-length enamel rods that are supported on the cavity side by shorter enamel rods, all of which extend to sound dentin.

Finishing the external walls Ⅲ The design of the cavosurface angle The degree of smoothness of the wall

The design of the cavosurface angle: depending on the material amalgam: 90° composite: beveling 30°~ 40°

Final cavity preparation stage Step 5 Removal of any remaining infected dentin if indicated Step 6 Pulp protection Step 7 Secondary resistance & retention form Step 8 Procedure for finishing external walls Step 9 Final procedures

Final procedures cleaning inspecting varnishing conditioning

Program of Operative Treatment Cavity preparation Matrix application Preparation of materials Insertion and carving of materials Finishing and Polishing

Matrix Application Tofflemire Matrix System Ivory Matrix System

Matrix retainer, Band & Wedge

Rounded instrument such as a spoon excavator Contour Matrix

Matrix in Retainer

Matrix on Tooth

Occlusal View

Wedge place

Contour Band

Ready for restoration

Program of Operative Treatment Cavity preparation Matrix application Preparation of materials Insertion and carving of materials Finishing and Polishing

Program of Operative Treatment Amalgam Capsule Amalgamator Squeeze Cloth Amalgam carrier

Activate Mercury

Amalgamator

Amalgam carrier Squeeze Cloth

Amalgam carrier Amalgam plugger

Program of Operative Treatment Cavity preparation Matrix application Preparation of materials Insertion and carving of materials Finishing and Polishing

Insertion and carving Class Ⅱ Class I

Amalgam Restorative Instruments Amalgam Condensers Anatomic Burnishers CarversCleoid or Discoid

Check condenser fit

First increment

Start with the smallest condenser

Step condenser over mass

Continue adding increment

Condense toward walls

Use alternative instruments

Overpacked

Create initial grooves

Create initial grooves

Carve to margin

Enhance grooves

Remove flash

Final shape and burnishing

Completed restoration

Initial Increment

Initial Condensation

Lateral Condensation

Lateral Condensation

Overpacking

Marginal Ridge Condensation

Condense to Margins

Create Occlusal Embrasure

Occlusal Embrasure

Occlusal Embrasure

Occlusal Embrasure

Removing Ridge

Removing Band

Flash & Excess

Check with interproximal carve

Instrument on Tooth Structure

Completed Restoration

Rubber dam removal

Program of Operative Treatment Cavity preparation Matrix application Preparation of materials Insertion and carving of materials Finishing and Polishing

Polishing kit

Polishing

Evaluate the restoration Class I Verify that cavosurface margin can be seen Flash Underfilled Voids Check the overall shape of the anatomy Look for bulky ridges that might be high in occlusion

Evaluate the restoration Class II Check proximal contact Check flash and overhangs proximally Check underfill proximally Check outline form

Check Occlusion Evaluate carefully with marking paper or ribbon in Miller forceps Check gently in centric occlusion Check all excursive movement

How to Place Matrix Band in Tofflemire Retainer

Tofflemire retainer with Matrix band placement on Tooth

matrix

Thanks