Clinical evaluation of a posterior composite 10-year report

The 10-year findings of one of the studies which comprised the multicentre clinical evaluation of a light-cured posterior composite restorative are reported, with special emphasis on the reasons and timing of failure of restorations included in the study. Effects of the use of rubber dam or cotton rolls and aspiration for isolation at the time of placement are considered.

One hundred Class I and II restorations of the resin composite investigated were placed by a single operator in a group of selected, predominantly young-adult patients under highly controlled conditions, with the use of rubber dam or cotton rolls and aspiration for isolation being determined according to a scheme of randomisation. The restorations were reviewed clinically after 1 week and within 1 month of placement (baseline) and, thereafter, at 6 months, 1, 2, 3, 4, 5, 6 and 10 years using modified USPHS codes and criteria. Epoxy models and photographs were obtained for retrospective analysis.

After 10 years, 37 restorations were reviewed and 32 restorations were known to have failed. Regarding the reasons for failure, loss of occlusal anatomic form during the first 5 years and loss of approximal contacts near the end of the study accounted for most of the failures. Only two failures were attributed to recurrent caries. Few of the restorations found to be clinically satisfactory at 10 years had retained ideal functional characteristics. Location, Class and size of restoration and the method of isolation were not found to significantly influence 10-year performance and survival.

The actual 10-year failure rate, estimated to have been between 40 and 50% is considered to have been high, notably given the limited incidence of recurrent caries and bulk fracture. However, the findings indicate that certain restorations of the material investigated, despite the use of outdated operative techniques, may be found to perform satisfactorily over periods in excess of 10 years.