A COMPARISON OF 2 IN-VITRO METHODS FOR ASSESSING THE FITTING ACCURACYOF COMPOSITE INLAYS

Composite inlays were fabricated in standardised cavities cut into alu minium and perspex blocks using a computer controlled milling process. Four materials were used to construct the inlays. These were fabricat ed using an indirect technique following the manufacturers' recommenda tions, where applicable. In addition, for one of the composites, the f abrication procedures were modified. The fitting accuracy of the resto rations was assessed by taking elastomeric impression wash replicas of the luting space and by examination of sectioned restored units using image analysis. The former method indicated significantly reduced fit ting accuracy when either use of die spacer or secondary curing was om itted from restoration construction resulting in incomplete seating. T he sectioning technique indicated that more factors appeared to signif icantly reduce fitting accuracy including bulk packing, alteration in curing time, omission of die spacer and the final polishing procedure. This method also provided more specific information concerning sites of premature contact. One material gave rise to significantly greater film thicknesses using both methods of assessment. No direct correlati on was found between the two techniques of fit evaluation but both met hods taken together provided complementary information.