Dr.Gaurav Garg ( M.D.S.) Lecturer, College of Dentistry Al Zulfi, M.U. RESTORATION OF CLASS I & CLASS V PREPARATION Assalaam Alekum 6/10/2015

Contents Material & instruments required Restoration of Class I Preparation Restoration of Class V Preparation References & Suggested readings

MATERIAL & INSTRUMENTS REQUIRED Amalgam Material ( High Copper recommended) Amalgam Carrier Amalgam Condensers Burnishers Carvers Hollenbeck carver Ball burnisher Egg shape burnisher Round/cylindrical condenser Discoid- Cleoid Carver

RESTORATION OF CLASS I PREPARATION Prerequisite:  Isolation ( Rubber dam recommended) Principle Objective: To condense the amalgam to adapt it to the preparation walls and produce a restoration free of voids and have as low as possible mercury content in the restoration to improve strength and decrease corrosion

RESTORATION OF CLASS I PREPARATION STEPS IN RESTORATION:  Insertion  Condensation  Pre-carve burnishing  Carving, Contouring & finishing  Post-carve burnishing

RESTORATION OF CLASS I PREPARATION Procedure: Before inserting the amalgam, review the outline of the tooth preparation to form a mental image that will aid later in carving the amalgam to the cavosurface margin and remembering the preoperative occlusal contact locations Usually a matrix is not required Use an amalgam carrier to transfer mixed amalgam to the tooth preparation Increments extruded from the carrier should be smaller (often only half or less of a full-carrier tip) for a small preparation, particularly during the initial insertion

RESTORATION OF CLASS I PREPARATION Use a flat-faced, circular condenser to condense the amalgam over the pulpal floor of the preparation Condense the amalgam into the pulpal line angles properly The initial condenser should be small enough to condense into the line angles but large enough not to "poke holes" in the amalgam mass Usually a smaller condenser is used while filling the preparation and a larger one for overpacking

RESTORATION OF CLASS I PREPARATION Thoroughly condense each portion extruded from the carrier before placing the next increment Each condensed increment should fill only one third to one half the preparation depth Each condensing stroke should overlap the previous condensing stroke to ensure that the entire mass is well condensed The preparation should be overpacked 1 mm or more using heavy pressure This will ensure that the cavosurface margins are completely covered with well condensed amalgam

RESTORATION OF CLASS I PREPARATION Condensation of a mix should be completed within the time specified by the manufacturer (usually 2 ½ to 3 ½ minutes) Otherwise, crystallization of the unused portion will be too advanced to react properly with the condensed portion Discard the mix if it becomes dry, and quickly make another mix to continue the insertion

RESTORATION OF CLASS I PREPARATION Pre-carve burnishing: To ensure that the marginal amalgam is well condensed before carving, the overpacked amalgam should be burnished immediately with a large burnisher using heavy strokes mesiodistally and faciolingually while contacting cusp slopes (not margins) It produces denser amalgam at the margins & initiates carving

RESTORATION OF CLASS I PREPARATION Contouring and Finishing the Amalgam: Carving may begin immediately after condensation Use the larger discoid-cleoid carver (No. 3-6) first, followed by the smaller instrument (No. 4-5) in regions not accessible to the larger instrument All carving should be done with the edge of the blade perpendicular to the margins as the instrument is moved parallel to the margins Part of the edge of the carving blade should rest on the unprepared tooth surface adjacent to the preparation margin using this surface as a guide to prevent overcarving the amalgam and to produce a continuity of surface contour

RESTORATION OF CLASS I PREPARATION Overcarving & Undercarving should be avoided A restoration that is more than minimally overcarved (i.e., a submarginal defect greater than 0.2 mm) should be replaced The mesial and distal fossae should be carved slightly deeper than the proximal marginal ridges After carving, the amalgam restoration should reflect the proper anatomy & contour

RESTORATION OF CLASS I PREPARATION If total carving time is short enough, the smoothness of the carved surface may be improved by wiping with a small, damp ball of cotton held in the tweezers Some operators prefer to post-carve burnish the amalgam surface using a small burnisher when carving is completed Post-carve burnishing is done by lightly rubbing the carved surface with a burnisher of suitable size and shape to improve smoothness.

RESTORATION OF CLASS V PREPARATION Matrix Placement: Most Class V amalgam restorations are placed without the use of any type of matrix But in a tooth preparation with an axial wall that is very convex mesiodistally the condensation of amalgam would be difficult In such case two alternative methods for insertion may be used. 1. Application of a matrix (secured with wedges & impression compound) that confines the amalgam in the mesial and distal portions of the preparation (Most Preferred) Impression compound

RESTORATION OF CLASS V PREPARATION 2. A conventional Tofflemire band and retainer may be used with a window cut into the band allowing access to the preparation for condensation

RESTORATION OF CLASS V PREPARATION Amalgam condensation: 1. Using the amalgam carrier, insert the mixed amalgam into the preparation in small increments and condense it into the retention areas first, with an appropriately sized condenser 2. Next, condense the amalgam against the mesial and distal walls of the preparation 3. Finally, provide sufficient bulk in the central portion to allow for carving the correct contour

RESTORATION OF CLASS V PREPARATION As the surface of the restoration becomes more convex, condensation becomes increasingly difficult. The operator must guard against the amalgam's "land sliding" during over packing. A large condenser or plastic instrument held against the amalgam may prevent this (or use matrix)

RESTORATION OF CLASS V PREPARATION Carving: Carving may begin immediately after insertion of the amalgam All carving should be done using the side of the explorer tine or a Hollenback No. 3 carver held parallel to the margins. In addition, the side of the carving instrument should always rest on unprepared tooth surface adjacent to the prepared cavosurface margin to prevent overcarving Hollenback carver

RESTORATION OF CLASS V PREPARATION  Steps in Carving: 1.Begin the carving procedure by removing excess amalgam to expose the incisal (or occlusal) margin. 2.Continue removing excess to expose the mesial and distal margins. 3.Finally, carve away excess at the gingival margin. Carving the marginal areas should result in developing the desired convex contours in the completed restoration (no under or overcarving). There should be no amalgam excess at the margins, because it may either break away, creating a defect at the margin, or cause gingival irritation

References & suggested readings 1. Art and science of operative dentistry- Sturdevent’s, Principles of Operative Dentistry- A.J.E. Qualtrough,2005