Marginal Accuracy Comparison Between Acrylic, Wax and CoCr-Sintermetall Ceramill Sintron®

Introduction: The use of manufacturing dentures computer aided (CAD/CAM) systems is a reality for the dental community. Today there are many materials for use in these systems. Objectives: Investigate the advantages of eliminating laboratory steps such as: inclusion and casting in getting prosthetic copings and infrastructure; in the case of replacement by the use of pre-sintered metal (CoCr) and whether it still has better marginal adaptation when compared to infrastructure manufactured in wax and acrylic burnout. Methods: Two waxes, two calcinable acrylics and a pre-sintered metal were tested. G1: Acrylic burnout and G3: Wax burnout both the company AmannGirrbach G2: Acrylic burnout and G4: Wax burnout both VIPI. And G5: Metal pre-sintered CoCr from AmannGirrbach company. The specimens (n=10) were obtained through CAD/CAM system, by scanning a metal master die, which was later used to make measurements of marginal adaptation. The copings of each group were fixed to the master die with molten wax, and then an analysis in optical microscopy was performed with a 25X of increase to check marginal adaptation. Four readings were obtained by face of each coping generating a total of 160 readings per group. A statistical analysis was conducted with the aid of analysis of variance with one factor (0.05) and ANOVA (p <0.01). Results:   G2: 257.60±128.64 showed the highest average value of marginal gap (μm), followed by G1: 179.72±112.37; G4: 82.70±72.99; G3: 49.09±52.14, and G5: 9.81±6.12. Statistical analysis indicated differences between all groups (p <0.01). Conclusion: Within the limitation of this study it can be concluded that the G5 showed a significant better marginal adaptation than the other groups. Nevertheless G3 and G4 showed results within the limits stipulated by the literature (120μm). The pre-sintered metal can be a good alternative to minimize steps and achieve good results in marginal adaptation.