Manipulation of dental cements lab 1 video

Manipulation of dental cements  lab 1 video 

CEMENTATION Cements are generally hard, brittle materials formed when a powder edoxide orglassismixedwitha liquid. When mixed to a cementing consistency, dental cements are used to retain restorations such as alloy or ceramic crowns

and bridges and esthetic inlays, onlays, and veneers. When mixed to a thicker consistency, some cements can be used as temporary filling materials or to provide thermal insulation and mechanical supportto teeth restored withother materials, such as amalgam, composites, or gold. Cements classified as low-strength bases or liners provide protection to the pulp from irritants or serve therapeutically as pulp-capping agents. Varnishes are not cements but are used with cements to provide pulpal protection from irritants. Other cements are used for special purposes in endodontics and orthodontics.Cements are classified according to function in Table 7-1. The retention of restorations on prepared teeth is a major functionofdentalcements.Long-termcementationisrequired for permanent restorations such as crowns and bridges (see Figures 1-7 and 1-9). Strong cements—such as glass ionomer, resin-modified glass ionomer and resin cement—are used for permanent cementation. Often, a bridge must be cemented temporarily to allow adjustments in fit, occlusion, and esthetics,ortemporaryrestorations,suchasaluminum,acrylic, or composite provisional restorations, mustbe cemented for 4 to 8 weeks until the permanent restoration is ready. In these cases, temporary cements are used because of their low strength and good handling characteristics. Cements are classified as water-based, oil-based, or resin-based products. Information on zinc phosphate, zinc polycarboxylat