In in-vitro evaluation of effect of different finish lines on marginal adaptation in metal-ceramic restorations under thermo-mechanical loading.

The aim of this study was to evaluate the marginal gap in terms of cement film thickness associated with shoulder, shoulder with 45° bevel, shoulder with 30° bevel and chamfer, under thermo-mechanical loading. Forty human mandibular molars were prepared and restored with ceramo-metal crowns. Teeth were thermo-mechanically loaded and vertically sectioned to evaluate the cement film thickness. Shoulder with 45° bevel provided the least marginal gap as compared with all the tested finish lines.