Fillings

Composite Fillings: A Basic Understanding

Composite fillings are white, tooth colored fillings that are used to repair both small and large cavities. They can also be used in the event of a chipped tooth to fill in the missing area. Since these fillings are easily camouflaged on teeth, they are often preferred by patients. Most dentists now use this type of filling on a daily basis.

White fillings are made of a resin material that actually bonds to the tooth when applied. They are completely non-toxic to the body and withstand strong chewing pressure. The unique bonding application makes a tooth less likely to crack over time. On the contrary, silver amalgam fillings tend to expand over time, which greatly increases the risk of tooth fracture. White fillings do not expand, but they can shrink as they age. The average composite filling will last 7-10 years, but many will last much longer.

Less tooth structure is removed when preparing the tooth for a composite filling. This reduces the chance of irritating the nerve when repairing deeper cavities. Once the tooth has been cleaned and prepared, a bonding material is placed at the base of the preparation site. The resin material is then placed in layers, and a special light is used to harden each layer. This process takes a bit more time than other filling materials.

White fillings tend to have fewer sensitivity issues after placement, as compared to metal ones. While some composite fillings can be initially sensitive to hot and cold, this will diminish over a short period of time. Sometimes, the filling may be high, which causes a sharp pain when chewing. If this is the case, a quick trip to the dentist for a bite adjustment will fix the problem.

People with a lot of silver fillings may also request that they be replaced with composite ones. This will dramatically change the patient’s smile, giving them more confidence. A consultation with the dentist can determine whether or not your fillings can be easily replaced.

Amalgam Fillings

Dental amalgam is a mixture of metals including mercury, copper, silver and tin. Amalgam fillings have been used for over 150 years to fill cavities in dental patients caused by tooth decay. They are sometimes referred to as “silver filling” because of the color. To place amalgam fillings, the dentist drills to remove the decayed area of the tooth and properly shape the cavity for filling. If the filling is going to be an “unbonded” type, ledges and other structures may need to be created in the tooth to hold the filling in place. The alloy powder part of the amalgam, which contains the copper, silver and tin, is mixed with the liquid mercury portion of the filling to make a putty. The putty is then placed into the cavity where it hardens to a solid.

Benefits of amalgam fillings:

• –the least expensive filling material available
• –durable and long-lasting
• –able to withstand the forces of chewing
• –less likely to break than other materials
• –only require one visit to the dentist to fill

Drawbacks of amalgam:

• –contains mercury, which is associated with damage to the brain and kidneys in high amounts
• –some patients have sensitivity to the materials in the amalgam which might cause irritation or oral lesions
• –fillings can contract and expand, which can lead to gaps and cracks, providing places for bacteria to develop
• –over time, amalgam fillings can corrode or tarnish
• –some patients prefer the appearance of composite, or tooth-colored, filling

The FDA has studied dental amalgams extensively and has proven them safe, but the mercury content is still concerning to some patients. If you are concerned about your amalgam fillings, it is important to contact your dentist to discuss your options. If your fillings are in good shape, there is usually no reason to replace them, since the procedure would require additional drilling into healthy tooth structure and you could be exposed to additional mercury vapor during the process. However, if your fillings have become loose over time or gaps have developed that are allowing bacteria to develop and possibly lead to decay, it might be time to consider having them replaced.