A comparative evaluation of the marginal fit of dental copings fabricated by direct metal laser sintering and lost wax technique with two different finish lines - An in vitro study.

Abstract

Aim: The purpose of this in vitro study was to compare the marginal fit of dental copings fabricated by direct metal laser sintering (DMLS) and the lost wax technique with two different finish lines.

Settings and design: The study followed an in vitro experimental design.

Materials and methods: Two typodont mandibular right first molars were prepared with chamfer and shoulder finish lines. Impressions were made and 28 gypsum replicas for each margin were fabricated. Among the 28 samples with chamfer margins, 14 were prepared with the DMLS technique (Group A) and 14 using the lost wax technique (Group B). Similarly, among the 28 samples with shoulder margins, 14 were prepared with the DMLS technique (Group C) and 14 using the lost wax technique (Group D). Co-Cr copings were evaluated for marginal gaps under a stereomicroscope.

Statistical analysis used: SPSS software for Windows (Statistical Presentation System Software, SPSS Inc.) version 17.0 was performed using the statistical analysis. Student's t -test, one-way ANOVA, and Tukey post hoc test were done.

Results: All groups demonstrated clinically acceptable marginal fit, but the differences were statistically significant ( P < 0.05). Among the four groups, copings fabricated using the DMLS technique with a shoulder finish line exhibited superior marginal fit.

Conclusions: Considering the constraints of the study, superior marginal fit was exhibited by Co-Cr copings prepared with DMLS technique. When the finish line was considered, copings with the shoulder finish line exhibited the least marginal discrepancy.