Tooth-colored fillings are used to repair minimal tooth fractures, tooth decay, or otherwise damaged surfaces of the teeth. Dental filling materials may be used to even out tooth surfaces for better biting or chewing. In many cases, individuals with enamel loss resulting in tooth sensitivity will notice a significant improvement or complete elimination of sensitivity once the appropriate dental filling material is placed. 

There are many choices when it comes to procedures for damaged or decayed teeth, even when considering which type of dental filling material to use. For example, individuals have the choice of white "tooth colored" fillings (composite or porcelain) or silver amalgam restorations. Furthermore, many people today decide to replace old silver amalgam fillings with newer white "tooth colored" composite fillings.

In the past, composite fillings were not as durable as amalgams. However, dental manufacturers have made great strides in improving the strength of composite resin materials so that composite fillings today have the potential to be used for all teeth, including molars. Furthermore, composite materials often require less tooth preparation and may not weaken the affected tooth as much as amalgam fillings which often require more extensive tooth preparation. However, amalgam fillings do have along term-track record and may last longer than composite fillings.

Tooth Shaping: Both types of fillings require preparation of the affected tooth, but less preparation is usually required for a composite filling. This often means less healthy tooth structure has to be removed when placing a composite.

Technique and Time: Composite fillings are highly technique sensitive. This type of restoration also requires the use of additional equipment. Additionally, the composite procedure requires up to 50% more time than the amalgam filling procedure. These factors contribute to higher costs associated with composite fillings. In fact, composite fillings are more expensive than amalgams, and most dental insurance companies do not absorb the additional costs.

Skill: Not all dentists are skilled in composite fillings, making the decision of selecting a dentist an important factor in treating tooth decay or damage. Post graduate education is a critical factor for all dentists in order to refine their skills in composite restorations.

Fillings: The Procedure
During preventative dental hygiene checkups or dental emergency visits prompted by a toothache, your dentist will evaluate your teeth, gums, and supporting bone structure. He or she will identify the number of tooth surfaces that are affected by tooth decay or damage, and then prepare the tooth and necessary surrounding areas in order to restore the damaged area. Your dentist will remove the decay or damaged area with a dental hand-piece or laser, cleanse the area to remove bacteria or debris and complete the restoration.

During a composite filling procedure the tooth is isolated. Tooth isolation is critical in a composite restoration, because it prevents moisture from interfering with the bonding process. The bonding procedure requires the placement of various adhesives followed by the composite material that is then hardened with a special bonding light or laser.

Types of tooth –colored Filling
There are basically three types of tooth-colored materials which are used to restore posterior primary teeth: resin-modified glass ionomers, composites, and compomers. Resin-modified glass ionomers (RMGI) are glass ionomer cements to which a resin has been added for strength. Composites are a tooth colored material consisting of two main components: a matrix and filler. Compomers are polyacid-modified resin composites. They consist of a single, hydrophobic resin which is filled with acid-leachable glass particles similar to those found in glass ionomer cements.

Conventional glass ionomers are derived from aqueous polyalkenoic acid and a glass component. When the powder and liquid are mixed together, an acid base reaction occurs. Resin-modified glass ionomers (RMGI) work by the fundamental acid-base reaction, which is supplemented by a second resin polymerization reaction.

In addition to its micro-mechanical adhesion to dentin, enamel, and cementum - RMGI chemically bonds to the calcium in dentin and enamel.

RMGI also releases fluoride. Fluoride is released from glass ionomer and RMGI not only when it is placed, but also after fluoride treatments and brushing with fluoride toothpaste. This is because glass ionomer acts as a fluoride reservoir.

Finally - although the shear bond strength of RMGI to tooth structure is only 4-5 mPa, this restorative material succeeds because its coefficient of thermal expansion is very close to that of a tooth. In other words, when the tooth expands, the RMGI expands in a like fashion.

Composites are composed of a resin matrix, inorganic filler, and an interfacial phase. The matrix provides the framework, and the filler imparts its mechanical properties onto the composite.

Compomers are similar to composites. They have a wear rate about 3 times that of a composite, however. In addition, compomers require placement of a bonding agent to ensure adequate retention to dentin surfaces.

Pros and Cons of tooth-colored filling;
Advantages; Resin-modified glass ionomer (RMGI) is a tooth-colored material that bonds chemically to the tooth, and releases fluoride for a relatively long period of time. An amalgam restoration neither releases fluoride, nor adheres to the tooth. Finally – less tooth enamel needs to be removed by the dentist when an adhesive, tooth-colored restoration is placed in a tooth, than when an amalgam restoration is placed.

Disadvantages; the time required for a dentist to place a tooth-colored restoration is usually greater than that required for an amalgam restoration. A tooth-colored restorative material is not as forgiving as dental amalgam insofar as the dentist’s clinical technique is concerned. Contamination of the cavity preparation may occur before the restorative material has been placed. A tooth-colored restoration is not as durable as an amalgam restoration. This is because it’s compressive and tensile strengths are not as great as that of an amalgam restoration. A composite restoration often “fails” because new caries can develop underneath the filling (recurrent caries).