Methods: Two trained clinicians placed 40 porcelain (P) (Vita Mark II/Vita) and 40 composite (C) (Paradigm MZ100/3M-ESPE) CAD/CAM inlays, in 43 patients. A CAD/CAM unit (CEREC 2/Sirona) was used to fabricate all restorations using COS 1.21 software. Following computergraphic design of the inlay, a prefabricated block was randomly assigned for each restoration. Both restorative materials were cemented with a total etch technique using Single Bond (3M-ESPE) and dual cured resin cement (RelyX-ARC/3M-ESPE). Restorations were evaluated by two examiners using modified USPHS criteria.
Results: At six years, there was no significant difference in margin adaptation or margin discoloration between the two materials, but the composite showed a significantly better color match (Chi-Square, p < 0.05). The porcelain inlays had a significant increase in margin detectability from baseline at 1, 2, 3 and 6 years and the composite inlays at 2, 3, and 6 years (Wilcoxon SRT, p < 0.05). Both materials showed a significant increase in margin discoloration at 6 years (WSRT, p < 0.05). The composite resin inlays showed no significant difference in color match at any recall period, while the porcelain inlays had a significant decrease in color match at 6 months (WSRT, p < 0.05), with no significant color change between 6 months and 6 years. Ratings for anatomic form, surface finish and recurrent caries were > 95% alpha for both materials at all recalls.
Conclusions: The composite inlays performed equally as well as the porcelain inlays after 6 years in all categories with significantly better color match and less bulk inlay fracture.
This study was supported by 3M-ESPE.