The term bonding is used to describe procedures where tooth-colored dental resins and composites are used. Direct bonding techniques can be used to change the shape and color of teeth as well as to close unattractive spaces. It can also be used to repair chipped or broken teeth or even to cover up unsightly stains. Unlike crowns or caps, direct bonding requires only a minimal amount of tooth reduction thus making it a very conservative procedure.
How It Works
After slight preparation, the tooth is etched with a weak phosphoric acid solution to create a more porous and rougher surface for increased bonding strength. Next, a composite (plastic) resin is placed on the tooth and shaped, contoured and hardened with a special curing light. It is then further shaped and highly polished creating a very natural appearance. The procedure usually requires only one visit and is not painful.
How Long It Lasts
The bonded composite has an average life of four to eight years, and often lasts longer depending on how and where in the mouth it is applied and how it is maintained. The area can be touched up and even re-bonded over time as necessary.
Tooth Colored Fillings
Natural tooth-colored fillings have become widely accepted and are often used in place of metallic restorations where aesthetics is a primary concern. There are even studies that show that in some cases, use of certain tooth-colored materials can strengthen a tooth, making it a better choice than the metallic predecessor – amalgam. Two basic types of tooth-colored restorations are used: composite and ceramic.
Composites have been used for many years however their chemical make-up has changed and improved exponentially. The bonding agents used to make the composites adhere to the tooth have improved just as dramatically. Because of the improvements, the use of composites has become widely accepted by dentists and the indications for their use are more numerous. They are being used to close undesirable spaces, improve the shape, size and color of a tooth, replace an unsightly amalgam restoration, cover abraded or worn areas of a tooth (usually at the gum line) and to cover stains. Composites can also be used to protect thermally sensitive areas and to repair and strengthen broken teeth.
How They Are Placed
Once the tooth has been prepared and all decay removed, chemicals and materials are placed on the tooth to increase bond strength and to protect the tooth. Next, the composite material is placed incrementally into the tooth and is hardened by exposure to a special curing light. The restoration is then contoured to fit the bite and then is highly polished. These fillings require a bit more time than the silver fillings because of the number of steps involved. Composite fillings can also be a bit more sensitive, at first, to extreme hot and cold and they may discolor over time if the patient smokes or drinks a lot of coffee, tea or cola. They can also be more expensive and some composites may wear faster than silver fillings; however, they yield a much more natural and aesthetic result.