A composite (tooth colored) filling is used to repair a tooth that is affected by decay, cracks, fractures, etc. The decayed or affected portion of the tooth will be removed and then filled with a composite filling.
There are many types of filling materials available, each with their own advantages and disadvantages. You and your dentist can discuss the best options for restoring your teeth. Composite fillings, along with mercury amalgam fillings, are the most widely used today. Because composite fillings are tooth colored, they can be closely matched to the color of existing teeth, and are more aesthetically suited for use in front teeth or the more visible areas of the teeth.
As with most dental restorations, composite fillings are not permanent and may someday have to be replaced. They are very durable, and will last many years, giving you a long lasting, beautiful smile.
Reasons for composite fillings:
How are composite fillings placed?
Composite fillings are usually placed in one appointment. While the tooth is numb, your dentist will remove decay as necessary. The space will then be thoroughly cleaned and carefully prepared before the new filling is placed. If the decay was near the nerve of the tooth, a special medication will be applied for added protection. The composite filling will then be precisely placed, shaped, and polished, restoring your tooth to its original shape and function.
It is normal to experience sensitivity to hot and cold when composite fillings are first placed, however this will subside shortly after your tooth acclimates to the new filling.
You will be given care instructions at the conclusion of your treatment. Good oral hygiene practices, eating habits, and regular dental visits will aid in the life of your new fillings.
Disadvantages of mercury amalgam and composite fillings and matrix filled fillings:
The fact that amalgam contains mercury speaks for itself. Mercury hygiene has to be practiced or else problems will result for the staff and patient. Mercury is not a biological inert material. Aside from the toxic relationship that mercury has in amalgam, it is not the major disadvantage for the tooth. The problem with mercury amalgam is it's thermal coeficient expansion and the tooth cavity preparation that retains the mercury amalgam. Thermal Changes in temperature causes the mercury amalgam to expand and contract at a different rate than the tooth. This thermal cycling change increases at a square and qube of the filling mass. In other words, the bigger the filling the more the movement. Movement transulates into structural tooth stress, leaking, sensitivity and recurrent decay. In addition to the aforementioned, mercury amalgam is a metal and metals conduct heat much faster than a tooth can. Thermal sensitivity will be experienced with mercury amalgam fillings. A mercury amalgam filling is retained not bonded.
The retention is accomplished by cutting undercuts in the tooth anatomy. All tooth preparations that involve the undercut design violate anatomy of the tooth more than a inlay or inlay/onlay preparation. Violation of the anatomy is accomplished by cutting the dential tubes off and leaving unsubstained communication to the enamel. Dential tubes have plasma in them. The plasma maintains the integrity of the dentin. The dentin that is cut off from it's plasma supply will become dry and brittle. Between thermal cycling and drying of dentin, fractures and recurrent decay are inevitable. However, mercury amalgams placed in small conservative cavities (1-2mm in diameater) appear to last a long time.
Matrix band fillings that have the matrix in direct contact with tissue fluid will draw the fluid up to the margin of the cavity preparation. This physical fluid mechanics phenomena is called the capillary action. The Capillary action occurs when water moves upward through a small space. A small space such as between the outer surface of the tooth and the matrix band. The fluid can be blood or plasma, Either one is a contaminate to the composite or mercury amalgam. A restorations such as a Cerec does not employ a matrix band to be bonded. Therefore, less chance of contamination with no matrix band.