Stereomicroscopic Evaluation of Marginal Fit of Premachined and Castable Abutments at Implant Abutment Connection Interface – An In Vitro Study

Background: The precision fit at the implant-abutment interface is a significant criterion for the success of implant restorations clinically. Various factors are involved in it, including fabrication techniques and utilized materials. The misfit at the implant-abutment interface is capable of causing screw loosening and fracture of the abutment screws. Aim: The aim of the study was to evaluate the marginal fit of premachined and castable abutment at implant-abutment connection interface using stereomicroscope. Materials and Methods: Fifteen castable abutments (Group A) and 15 premachined titanium abutments (Group B) were used for the study and connected to titanium implants and evaluated under the stereomicroscope. Images of the sample were recorded at three equidistant points at the implant-abutment interface to measure the vertical microgap at the platform level. The data were subjected to statistical evaluation using the “ t ”- test. Results: Data were sent for the statistical analysis by the software Statistical Package for the Social Sciences version. The mean for Group A (customized abutments) at mesiobuccal point was 13.2199 with a standard error of 0.5281. For premachined abutments, it was 6.4629 and with a standard error of 0.3201. Similarly, the mean for Group A (customized abutments) at the distobuccal point was 12.0861 with a standard error of 0.3428. On comparative assessment, the mean microgap in between the groups showed significant difference (Tukey test). Conclusion: On implant-abutment interface at the platform level, the microgaps of premachined implant abutments were significantly lesser than the casted implant abutments. Furthermore, the microgap of both tested groups was found within the clinically acceptable ranges.