Dental restorations maybe internal or inlay, or external or onlay and these, in turn, may the partial or total.
The crown is a total peripheral restoration. It is indicated for functional or esthetic requirements, and may be metallic, acrylic, metal with porcelain, only porcelain, or of compound materials.
The preparation of the tooth to receive a crown varies according to the type of material that is used for its construction. The great challenge is to achieve peripheral sealing that prevents microbial colonisation (an objective that is very difficult to achieve), which would cause further caries. Because of this, the useful life of crowns is usually limited.
The veneers are also a prosthetic option when the esthetics of the anterior region need to be improved or when this region has lost its function. The veneers are planed to a thickness of 1mm to 2mm, respecting the point of contact between the teeth.
Partial prostheses used in the posterior segment may be inlay, in other words, contained within the tooth remnant, or onlay, when they partially cover the tooth remnant. They may be made of porcelain, composites or cast in metal.
The dental bridge is a prosthetic solution to replace one or several absent teeth. Nowadays this device is used less frequently due to the excellent results obtained with dental implants.
A bridge is composed of: a) the crowns fixed on to the tooth remnants; b) the pontic span; and c) the connectors that unite the bridge to the crowns.
The number of teeth that can be replaced by a single bridge is calculated using Ante’s law, which states that the surface area of the teeth to be replaced must be equal to or less than the surface area of the abutment teeth.
Different designs exist for the support of the pontic span on the gum, and these depend on the objective to be achieved, which may be esthetic or functional
The dental post is used to provide a support onto which to cement a crown restoration on a tooth that has lost its crown.
Posts may be designed in three ways: the first, by the impression with of the root canal with silicone or some other impression material; second, by direct impression with acrylic; and third, using preformed pegs.
These latter pegs may be metallic, fiberglass or carbon fiber. The ideal length for the post is of two thirds to three quarters of the total length of the dental root, and a minimum of 3mm of root obturation must always be left