Conservation of the natural tooth structure is the primary goal of the dentistry. A dental cavity on any tooth surface is initiations of tooth decay which, when left unnoticed, can lead to tooth infection, ultimately causing tooth loss in general.
A dental restoration or dental filling is a treatment protocol to restore the function, integrity, and morphology of broken or lost tooth structure because of caries or external trauma to the tooth structure.
Restorations help in the rehabilitation of the dentition to acquire a standard functional and aesthetic requirement of the individual.
Restoration of a tooth to achieve natural form and function requires two primary steps:
- The tooth preparation for placement of restorative material, and
- Placement of dental filling material inside the prepared Cavity
Tooth preparation involves cutting of the tooth with rotary instruments with the aid of dental burs to prepare a space for the planned restorative materials. Tooth preparation is performed not only to remove dental decay but also to eradicate areas of unsound support.
A radiographic examination can be done before the placement of dental filling material in cases of deep caries.
Depending upon the extent of caries involvement, a temporary restoration/ permanent restoration can be done immediately after tooth preparation.
Tooth Preparations may be divided into two types: –
Tooth preparations that are meant to hold dental filling material within the normal contours of the crown of the tooth.
These include cavity preparations for composite, amalgam, GIC as well as for gold and porcelain inlays.
Tooth preparations that are done to cover the outer surface of the tooth to restore the normal anatomic contours for masticatory function. These include full crowns and onlays and veneers.
During the preparation of a tooth for restoration, several factors are used to determine the type and extent of the tooth preparation. The carious decay of the tooth often guides the length of tooth preparation. The type of cavity preparation is determined by the area of the tooth involved with caries.
Unsupported tooth structure also plays an essential role in determining the extent of the cavity preparation. During cavity preparation, any unsupported enamel is removed before the final dental filling of the tooth. Unsupported enamel is often found on the margins of the cavities being prepared. Since unsupported enamel is too weak to support the dental filling, it should be removed.
Placement of dental filling material
Two techniques do the installation of dental filling material: –
This usually involves placement of a soft dental filling material prepared by mixing of powder and liquid in pre-determined ratios into the prepared tooth. The mixture requires a set time after which it hardens to produce a solid surface.
This saves a lot of time, and multiple visits to a dental clinic can be avoided as the entire procedure can be completed in a single appointment. An informed decision of the dental filling material is made based on the location and extent of The Cavity by the dentist.
During the setting of the cement inside the tooth cavity, an exothermic reaction ensues which leads to transfer of heat to the tooth. This might cause some discomfort which can be experienced by the patient.
In this technique, fabrication of the restoration is performed outside the mouth using impressions of the prepared Cavity. Commonly used indirect restorations are onlays, crowns, and porcelain veneers.
The fabrication of the indirect restoration is done by the dental laboratory from the oral records provided by the dentist. In cases of crowns and bridge work to replace a missing tooth, multiple visits to a clinic are required.
Initially, a trial is done to check the fitting of the framework. This is followed by a final restoration which is bonded permanently to the prepared tooth with a block of luting cement.
Classification of dental cavities
G.V. Black classified the cavities depending on their site into the following categories: –
- Class, I Cavity are those affecting pit and fissure, on occlusal, buccal, and lingual surfaces of molars and premolars, and palatal of maxillary incisors.
- Class II Cavity are those affecting proximal surfaces of molars and premolars.
- Class III Cavity are those affecting proximal surfaces of central, laterals, and cuspids.
- Class IV Cavity is those affecting proximal including incisal edges of anterior teeth.
- Class V Cavity are those affecting gingival 1/3 of facial or lingual surfaces of anterior or posterior teeth.
- Class VI Cavity is affecting cusp tips of molars, premolars, and cuspids.
Materials used for restorations
Restorations serve the purpose of an artificial substitute for the broken tooth surface. With the advancement in dental sciences, restorations on tooth surfaces have undergone a change from amalgam to tooth-colored restorations/dental fillings like cement and composite.
Tooth-colored cement dental fillings provide superior aesthetics in comparison to amalgam. They bond to the tooth by chemical bonding, thereby preventing secondary caries, which can adversely affect the remaining tooth structure. GIC used in dental fillings not only serves to repair the broken tooth structure but also provides a fluoride-rich environment to prevent further caries progression.
Composites as filling materials are generally considered as the choice of material in anterior or aesthetic zones of the dentition. They have a low tensile strength which renders them ineffective when used for posterior dental fillings.
Composites are used for tooth reconstruction in case of fracture of the tooth due to an accident or injury. They require minimum tooth preparation before the final filling is done. The procedure of placement of dental filling material can be completed in a single visit, thereby minimizing patient discomfort.
We, as a dental clinic in Dwarka, strive to provide for best dental filling material available at reasonable rates taking into consideration the patient requirements and the tooth surface involved. The dental filling materials available with us are required minimal tooth preparation and can adhere to the tooth surface by forming a chemical or mechanical bond depending upon the material used.