Biomaterial Based Specifity of CPM-Index: Impact for CCT

The accelerating development and introduction of restorative materials and the need of their clinical evaluation cause the necessity of index systems capable to compare materials of different origin such as metallic and non metallic. Objectives: The objective of this study was to evaluate the sensitivity and sensibility of the USPHS-compatible CPM Index (Clinical - Photographical - Micromorphological coding) for composite resin and amalgam restorations after a service time of four and ten years and to weight the qualitative parameters as for their impact on future clinical performance and survival rate. Material and Methods: Each 50 composite resin and amalgam restorations were followed up over a four and ten year period respectively and were evaluated according to the C-criteria of the CPM-Index. Results: The survival rate for composite resin restorations was 74%, the survival rate for amalgam 82% over the ten year period. The parameters surface roughness, surface texture, excess of material and marginal fracture exhibit material-specific codings, vary over time according to stereotype patterns and have no influence on clinical performance. The parameters marginal fracture and marginal leakage have significant influence on the survival of composite resin restorations but only little on the longevity of amalgam restorations. Thus the importance of qualitative parameters have to be weighted according to the material assessed when used for clinical controlled trials. Only the parameter other filling imperfections is insensitive to the evaluated restorative material but strongly correlates with the prognosis of the restoration. Conclusion: The CPM-index system is performing well in assessing and comparing the qualitative parameters of different restorative materials. Nevertheless qualitative parameters can only be correlated with survival and future performance of restorative materials, when weighted selective for materials of different (metallic and non-metallic) provenience. Supported by VOCO, Cuxhaven, Germany