Dental Fillings of the 1980s

Silver amalgam fillings have been a dental mainstay for more than 100 years. However, the 1980s brought some concerns over the mercury exposure patients received as a result of the use of amalgam. Because of these concerns, a lesser-known substance called composite became more popular, although it was not suitable for use on posterior or back teeth. Cast gold restorations, such as crowns, bridges and inlays were also common in the 1980s.

Amalgam Filling Material

• Amalgam filling material is a silver alloy that contains silver, tin, copper, zinc and mercury. It is the most commonly used restoration material in the United States. Aside from gold, it is the most consistent filling material for teeth. The basic materials are mixed with the mercury in pre-filled capsules. The amalgam is then mixed in an amalgamator for a length of time, dependent on the size of the mixture in the capsule, then carried to the tooth with an instrument called an amalgam carrier. Virtually white, once finished, the filling must oxidize to get the gray-silver color that everyone recognizes. Amalgam fillings are strong and long lasting, able to handle the impact of the human bite better than any other restorative material other than gold.

Furor Over Amalgam

• During the 1980s, it came to light that the mercury contained in amalgam fillings perhaps was not healthy for the person wearing them. Thoughts were that mercury leached through the tooth and into the body. Mercury was blamed for everything from runny noses to prostate cancer. Although, 30 years later, there has been no conclusive testing that proves mercury causes any disease. People who have had amalgam fillings for decades continue to support them with no problem, although, there are still some who insist on having no silver in their mouths and pay for the expensive composite or gold just to play it safe.

Composite Resin

• Composite resin is an acrylic-based synthetic resin, with silica or glass as a filler, used exclusively for dentistry. Application is done using a complex bonding system. Acid etchant is first applied to open and roughen the pores of the tooth, then a bonding agent is applied and cured, or hardened, with a handheld ultra-violet light source. The composite resin is placed in the bonded areas, again utilizing UV light to cure it. Composite had long been used for anterior, or front, tooth restorations prior to the mercury scare of the 1980s. During the scare, it was in demand from patients who worried about mercury in spite of the fact that it did not have the ability to withstand the human bite when placed in posterior or back teeth. It was not for nearly two more decades that a composite became available that could compare to amalgam when it came to the strength of the human bite.

Cast Gold Restorations

• Gold is the most compatible metal to the mouth. Dental gold is a high karat of gold that is combined with a small percentage of silver and copper for strength, as gold by itself is extremely soft. Gold restorations fall into four categories; inlays, cast restorations that involve the proximal -- between the teeth, surfaces of the tooth. Onlays, cast restorations not involving the proximal surfaces of teeth. Cast crowns, whole tooth coverage restorations, and bridges, cast restorations that replace a missing tooth or teeth. Made from impressions of a patient's teeth, all cast restorations cement in place with dental cement. Gold restorations in the 1980s were the most expensive, though best restorations for the teeth and were the ideal solution for the silver-free back tooth filling problem for those who could afford them. Still, 30 years later, the same materials are in use for dentistry, having withstood the test of time.