Restorative Dentistry

Restorative dentistry

It is a branch of dentistry that deals with restoring teeth affected by the most common conditions – Dental caries or tooth decay. Dental caries can be present on the biting surfaces of teeth, approximal surface facing the adjacent tooth, or the angle of the tooth or it may involve a major portion of the tooth surfaces. The treatment is primarily aimed at removing all the decay and caries leaving behind healthy tooth structure which can then be restored to its normal function and anatomy, using various restorative materials. Initially, the commonly used material was silver amalgam, etc. However, with the demand for esthetics increasing in recent times, tooth coloured fillings are more preferred.

COMPOSITE RESIN /LIGHT CURE RESTORATIONS (TOOTH COLOURED RESTORATIONS)

They are types of synthetic resins, which are used in dentistry as restorative materials or adhesives. They are most commonly composed of Bis-GMA and other dimethacrylate monomers, a filler material such as silica, and most applications, a photoinitiator. The composite resin is available in the form of tubes, through which it is dispensed, and different shades simulating the various tooth shades and stains are available so as to make the final restoration look as natural as possible. Prior to filling in the cavity, the tooth surface is etched with etchant which is normally 30-40% phosphoric acid, and then rinsed with water and air dried. This leaves behind a frosty white surface.

Following this, a bonding agent is applied, and cured. Composites are placed while still in the dough-like stage, in increments (packable) or flowable state, followed by activation by light of blue wavelength emitted from a light cure unit. This causes the composite resin to harden or polymerize into a solid filling. If filling is deep and too close to the nerve inside the tooth, some patients can complain of sensitivity. The biting surface also has to be adjusted to make it comfortable, otherwise patient can get sensitivity on eating or chewing. After the adjustments are done every filling is finished with aluminum oxide discs and polishing strips to get a smooth surface. A properly placed composite is comfortable, esthetically pleasing, strong, durable, and could last for several years. It is generally very difficult to distinguish between a natural tooth structure and composite resin restoration, if done properly.

GLASS IONOMER RESTORATIONS- RMGI

It is a dental restorative material for fillings and cementation of crowns. It is based on reaction of silicate glass powder and an ionomer. They bond chemically to dental hard tissues and release fluoride for a long period. It generally sets in 6-8 minutes. It is generally opaque cement. Even though it is used in the anterior teeth, it is opaque and not highly esthetic. Sometimes resins are added to make it more translucent. This is Resin Modified Glass Ionomer, which is light cured. These are glass ionomers that are modified by the inclusion of a resin monomer.

They are stronger and have an improved translucency over the original glass ionomer cement that set through an acid base reaction. Following placement, the top layer of the restoration will be irradiated for 20 seconds, following which it sets and attains a smooth glassy surface.Different types of fillings are indicated for cavities on:

Class I, (on the biting surfaces of molars and premolars), Class II (on the approximal surfaces between two teeth), Class III (angle of the front teeth) Class IV (angle and incisal edges of front teeth).

Direct composite veneers (tooth coloured outer layer of restorative resin material for discolured teeth/ intrinsic stains / hypoplastic (hypomineralized teeth with whitish areas) and diastema closure (gap between central incisors or other incisors.

INLAYS AND ONLAYS:

Sometimes a tooth is planned to be restored with an intracoronal restoration, but the decay or fracture is so extensive that a direct restoration such as amalgam or composite would compromise the structural integrity of the restored tooth or provide improper occclusal or biting forces. In such situations, an indirect gold or porcelain inlay may be fabricated. An onlay is the same as an inlay, except that it extends to replace a cusp. Crowns are onlays that completely cover all surfaces of teeth.

Indirect Porcelain veneers: These are thin outer layer, tooth coloured esthetic restorations covering the entire surface of the tooth. A thin layer of the enamel is removed and a margin prepared, then an impression is made and sent to the lab, where the porcelain veneer is fabricated and then it is cemented on to the tooth. These are generally performed for smile designing procedures, for hypoplastic teeth, intrinsic stains, fluorosis and diastema (gap) closure.