Direct restorations

This technique involves placing a soft or malleable filling into the prepared tooth and building up the tooth before the material sets hard. The advantage of direct restorations is that they usually set quickly and can be placed in a single procedure. Since the material is required to set while in contact with the tooth, limited energy can be passed to the tooth from the setting process without damaging it. Where strength is required, especially as the fillings become larger, indirect restorations may be the best choice in some cases.

Indirect restorations

This technique of fabricating the restoration outside of the mouth using the dental impressions of the prepared tooth. Common indirect restorations include inlays and onlays, crowns, bridges, and veneers. Usually a dental technician fabricates the indirect restoration from records the dentist has provided of the prepared tooth. The finished restoration is usually bonded permanently with a dental cement. It is often done in two separate visits to the dentist. Common indirect restorations are done using gold or ceramics.

While the indirect restoration is being prepared, a provisory/temporary restoration is sometimes used to cover the prepared part of the tooth, which can help maintain the surrounding dental tissues.

Removable dental prostheses (mainly dentures) are considered by some to be a form of indirect dental restoration, as they are made to replace missing teeth. There are numerous types of precision attachments (also known as combined restorations) to aid removable prosthetic attachment to teeth, including magnets, clips, hooks and implants which could be seen as a form of dental restoration.

The CEREC method is a chairside CAD/CAM restorative procedure. An optical impression of the prepared tooth is taken using a camera. Next, the specific software takes the digital picture and converts it into a 3D virtual model on the computer screen. A ceramic block that matches the tooth shade is placed in the milling machine. An all-ceramic, tooth-colored restoration is finished and ready to bond in place.

Another fabrication method is to import STL and native dental CAD files into CAD/CAM software products that guide the user through the manufacturing process. The software can select the tools, machining sequences and cutting conditions optimized for particular types of materials, such as titanium and zirconium, and for particular prostheses, such as copings and bridges. In some cases, the intricate nature of some implants requires the use of 5-axis machining methods to reach every part of the job.^[1]

Restoration classifications

GV Black Classification of Restorations

Greene Vardiman Black classified the fillings depending on their size and location.^[2]

• Class I Caries affecting pit and fissure, on occlusal, buccal, and lingual surfaces of posterior teeth, and lingual of maxillary incisors.

• Class II Caries affecting proximal surfaces of molars and premolars.

• Class III Caries affecting proximal surfaces of centrals, laterals, and cuspids.

• Class IV Caries affecting proximal including incisal edges of anterior teeth.

• Class V Caries affecting gingival 1/3 of facial or lingual surfaces of anterior or posterior teeth.

• Class VI Caries affecting cusp tips of molars, premolars, and cuspids.