The goal of this study is to quantitatively and qualitatively measure the sealed posterior composite restoration at time of placement and identify one year changes that may result due to wear. Limited extension posterior composite restorations have become the treatment of choice for minimally carious permanent teeth in children and adolescents. The approach appears to have many advantages over traditional amalgam restorations. There are few clinical studies which report on the long term success of these restorations or describe their performance in quantitative terms. This investigation proposes to use a computer guided profilometric system to record changes in the surface contour of these restorations at given time periods and compare these changes electronically to the original contour of the tooth and of the restoration at time of placement. The system will record the following: volume of restorative material used, volume loss of material with time, area of posterior composite used, area of sealant used and change in surface area of sealant. The location and extent of any sealant wear will be identified and related to the underlying composite. Following a clinical examination, including bitewing radiographs, forty child patients who require this type of restoration will be identified through the Department of Pediatric Dentistry at the University of Minnesota. Only class I restorations in lower first permanent molars will be included in the study. Each tooth will be impressioned with polyvinyl siloxane prior to cavity preparation, after tooth preparation is completed and immediately following completion of the restoration. After one year patients will be recalled and the restoration will be evaluated clinically and an impression taken. The principal investigator will place all restorations using a standardized technique. Epoxy replicas will be made from baseline impressions and sequential impressions. Surfaces of each replica will be profiled and digitized using a displacement stylus and data retrieval system. Computer generated graphic images of each surface will be obtained and stored for analysis. A """"""""goodness of fit"""""""" program will be used to calculate restoration volume, depth, and surface area. Qualitative information describing the occlusal distribution of the restorations, and how that is influenced by wear, will also be obtained.
