Preclinics of Conservative Dental Medicine · MU Sofia
28. Cast metal restorations – armamentarium, preparation methods, adjustment, cementation and removal.
Covers the making and fitting of cast gold-alloy inlays and onlays, from the burs and hand instruments used to prepare the cavity through direct and indirect pattern methods and the lost-wax casting steps. It then goes through impression and provisional restoration, try-in and adjustment, cementation with a comparison table of zinc phosphate, glass ionomer and resin cements, and finally removal by sectioning with common mistakes.
Topic 28 of 53 in the MU Sofia syllabus for Preclinics of Conservative Dental Medicine (Dental Medicine, Year 3). The free AceMed note covers it in 7 sections, about 904 words (7 min of reading), with 17 flashcards.
In this note
Introduction
Armamentarium
Preparation methods: direct and indirect
Impression and provisional restoration
Try-in, adjustment and cementation
Removal and typical mistakes
Key points
Introduction
Cast metal restorations – gold-alloy inlays and onlays – are made outside the mouth by the lost-wax technique and luted into a preparation with one path of insertion. They last only if the preparation has no undercuts, the impression is accurate, the try-in is careful and the cement film is thin and fully seated. Indications and preparation design belong to topic 27.
Armamentarium
Burs, with water spray: tapered fissure carbide burs – No. 271 (rounded corners) for the occlusal step and proximal boxes, the narrower No. 169L for tight areas and retention grooves. Their taper gives the walls a draft of 2–5° per wall. Slender flame-shaped fine diamonds cut the bevels.
Hand instruments: enamel hatchets and chisels plane the proximal walls; gingival margin trimmers bevel the gingival margin.
