E11. Identify the drawbacks with the traditional composites.

(Courtesy of D. Antonson)

Clinical slide showing a worn and stained Class IV restoration on 21 (international system).

The traditional composites are those materials that were developed during the 60s and the 70s. These materials contained filler particles that had average filler diameters of 40 um. These materials produced rough surfaces that were difficult to keep clean, which often resulted in a stained and discolored surface. As the composite surface started to wear, the matrix wore faster than the large filler particles. As a consequence, masticatory forces tilted and broke loose the partly protruding filler particles, which resulted in material loss (wear). In addition to the above shortcomings, the traditional composites also shrunk during polymerization as also modern composites do. However, at the time when the traditional composites were used, dentin bonding did not exists, which resulted in poor cervical bonding and gap formations in these regions. These gaps resulted in marginal staining and recurrent caries.

Because of the above shortcomings, the most common reasons for replacement of traditional composites were:

(After IA Mjör, 1981)

The above shortcomings that are still haunting the composites even though major improvements have occurred during the past 20 years.