Dental TOOTH AMALGAM RESTORATION Presentation on CD

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Includes the Adobe Acrobat Reader for reading and printing publications.

Numerous illustrations and matrices.

Contains the following key public domain (not copyrighted) U.S. Government publication(s) on one CD-ROM in both Microsoft PowerPoint and Adobe Acrobat PDF file formats:

TITLE:

Amalgam Restorations, 2003, 42 pages

SLIDE TOPICS, SUBTOPICS and CONTENTS:

Objectives List important aspects to consider when placing Class I dental amalgam Identify procedural steps used to place amalgam Identify procedural steps used to carve amalgam Objectives Identify the procedural steps used to check occlusion List important aspects to consider when placing Class II dental amalgam Identify the minimum satisfactory standards of an amalgam restoration Composition of Dental Amalgam Are these important aspects when placing amalgam? Silver 40 - 60% increases strength Tin 22 - 30% decreases expansion Copper 11 -27% increases strength & hardness Zinc <1% decreases oxidation & marginal breakdown Mercury 40-50% Wets the alloy particles/ decreases strength if in excess amounts Every alloy is different, see manuf. for details. Amalgam Setting Reaction with High Copper (Cu) Ag3Sn+Cu+Hg Ag3Sn+Ag2Hg3+Cu6Sn3 Silver-Tin + Copper + Mercury Silver-Tin+Silver-Mercury+Copper-Tin More Cu/less mercury is present in high Cu alloy. In high Cu alloy, Copper-Tin replaces Hg-Tin This phase is known as the “eta phase” Trituration “Mixing the amalgam” Over trituration decreases work time/less strength. Pellet is hot and shiny Under trituration retains more Hg Pellet crumbles *Before mixing- Check Prep “Ensure prep is workable” Cavity Preparation Requirements Depth- At least 2 millimeters at all locations to allow for proper thickness of amalgam. Width- At least 1 millimeter to allow for proper condensation and strength of material. Extension- Minimal extension advocated, consistent with removing decay and placing margins on sound tooth structure. Condensing Amalgam Definition- insertion and compression of amalgam in a cavity preparation so that the cavity is completely filled in a unified mass.. Purpose Promotes adaptation of amalgam to walls and margins of a cavity preparation. Removes voids creating a unified mass of amalgam. Reduces residual mercury if present. Effect of Condenser Tip The larger the nib, the greater the pressure required for adequate condensation. Begin filling the restoration with amalgam using a small condenser or to direct the material into undercuts and line & point angles of the preparation. Always use overlapping strokes when condensing. Restoring the Tooth Complete the restoration by over filling the cavosurface of the tooth with amalgam. Use sufficient condensing forces to cause the excess mercury to rise to the surface of the restoration. This will result in a stronger restoration. Always use a fulcrum (finger rest) to control the condensing force. Carving Remember your cavity outline- re-establish it by keeping the carver on the tooth structure at all times. Anatomy is not an option!! Should have buccal grooves, marginal and triangular ridges when appropriate. Carving (cont’d) Be sure to include mesial and distal pits when appropriate. Central occlusal groove should be present, but not overly deep or prominent. Carve the anatomy of the tooth in four lobes (two for premolars) corresponding to the natural cusps of the tooth. Burnishing Burnish amalgam restorations to: -seal up margins -smooth cavosurfaces *Amalgam should not be burnished until amalgam is almost set-up!! Occlusion Utilize articulating paper to ensure the restoration is not too high Have PT bite down lightly and laterally to identify premature contacts Pass dental floss through contact area to check proximal contact and remove debris (Class II only) Matrix Bands Used for class II restorations Two most common bands: -Universal band -MOD band Trim up to your need Wooden Wedge Minimizes amalgam being forced beyond the margin which in turn, creates overhangs. Separates teeth to compensate for thick band. Also can be contoured to achieve desired effect Condensing with Matrix Bands Class II Amalgam Con’t Use the interproximal carver (IPC) to remove excess amalgam from all margins of the proximal box. After initial set of amalgam, remove, wedge and matrix band. Check occlusion. OVERCONTOURED vs. UNDERCONTOURED Overcontoured Undercontoured “Flash” “Ditch” Undercarved Overcarved Fracture Harbors Plaque Pain Sensitivity Minimum Standards Amalgam must be well condensed. All margins must be sealed. Proximal contact must be restored where appropriate. Occlusal contact should be satisfactory.