Dental cement is a type of dental material that can be used for different purposes. Some cements are used to restore dental work, while others are used to create original dental work. Some are permanent, while others are temporary. Dentists must make sure to follow the manufacturer's directions for each type of cement, in terms of mixing, using the correct ratios and subjecting it to the correct temperatures. There are five types of dental cement: zinc-oxide eugenol, zinc phosphate, polycarboxylate, glass ionomer and composite resin.
Zinc-Oxide Eugenol liquid is composed of eugenol, water, ascetic acid, zinc acetate, and calcium chloride. The powdered version is composed of zinc oxide, magnesium oxide, and silica. It comes in two types - the first is weaker and is useful for temporary cementation, and the second includes reinforcing agents that make it more effective in permanent cementation.
Zinc phosphate liquid is composed of phosphoric acid, aluminium phosphate, and water. The powdered version is composed of zinc oxide, magnesium oxide and silica. It also comes in two types—fine grain and medium grain. The first type is used for permanent cementation of crowns, inlays, onlays and bridges. It creates a thin layer which is useful in accurate seatings of dentalwork. The second type is used as insulation for the filling of deep cavities.
Polycarboxylate is composed of polyacrylic acid, itaconic acid, maleic acid, tartaric acid, and water. The powdered version is composed of pure zinc oxide. Polycarboxylate is used for permanent cementation of stainless-steel crowns and orthodontic bands, and it can also be used as a base without causing irritation.
The liquid form of glass ionomer is composed of itaconic acid, tartaric acid, maleic acid and water. The powdered form is composed of zinc oxide, aluminum oxide and calcium. There are three types of glass ionomer. The first is used to cement metal restorations and orthodontic brackets; the second to restore eroded areas near the gingiva. The third to line or bond the dentine.
Composite resin is versatile when used as dental cement. Its low film thickness and insolubility in water enable permanent cementation. It is used to cement ceramic or resin inlays and onlays, ceramic veneers, orthodontic bands and brackets, and metal castings.