Authors : Masoud Ejlali, Aboulfazl Saboury and Maziar Sheikholeslami
Abstract: Numerous conflicting studies have been published regarding the importance of marginal adaptation of casting restorations on prepared teeth and moreover, the influence of investing methods. The present study examined the effects of four common investing methods (one-layer dry casting ring liner, one-layer and two-layer wet casting ring liner and ringless casting technique) on the marginal gap of castings on the die. Ten wax patterns were invested utilizing the aforementioned methods by phosphate-bonded investment. The marginal gap of each casting on a die was measured blind under a stereoscopic microscope. One way Analysis of Variance (ANOVA) with a Tukey HSD multiple comparisons Post-hoc test were statistically significant at p<0.05. The mean±SD for the castings marginal gap in the four investing techniques was 86±33 μm (one-layer dry casting ring liner), 42±32 μm (one-layer wet casting ring liner), 50±28 μm (two-layer wet casting ring liner) and 163±77 μm (ringless casting). The differences were statistically significant (p<0.05). The one and two-layer wet casting ring liner methods are the most reliable and appropriate techniques for the production of dental castings with the least marginal gap.
Masoud Ejlali, Aboulfazl Saboury and Maziar Sheikholeslami, 2010. The Effects of Dry and Wet Casting Ring Liners and the Ringless Casting Technique on Marginal Adaptation of Casting Crown. Research Journal of Biological Sciences, 5: 798-801.