Correlation between margin fit and microleakage in complete crowns cemented with three luting agents

Abstract

Microleakage can be related to margin misfit. Also, traditional microleakage techniques are time-consuming. This study evaluated the existence of correlation between in vitro margin fit and a new microleakage technique for complete crowns cemented with 3 different luting agents. Thirty human premolars were prepared for full-coverage crowns with a convergence angle of 6 degrees, chamfer margin of 1.2 mm circumferentially, and occlusal reduction of 1.5 mm. Ni-Cr cast crowns were cemented with either zinc phosphate (ZP) (S.S. White), resin-modified glass-ionomer (RMGI) (Rely X Luting Cement) or a resin-based luting agent (RC) (Enforce). Margin fit (seating discrepancy and margin gap) was evaluated according to criteria in the literature under microscope with 0.001 mm accuracy. After thermal cycling, crowns were longitudinally sectioned and microleakage scores at tooth-cement interface were obtained and recorded at x100 magnification. Margin fit parameters were compared with the one-way ANOVA test and microleakage scores with Kruskal-Wallis and Dunn's tests (α=0.05). Correlation between margin fit and microleakage was analyzed with the Spearman's test (α=0.05). Seating discrepancy and marginal gap values ranged from 81.82 μm to 137.22 μm (p=0.117), and from 75.42 μm to 78.49 μm (p=0.940), respectively. Marginal microleakage scores were ZP=3.02, RMGI=0.35 and RC=0.12 (p<0.001), with no differences between RMGI and RC scores. The correlation coefficient values ranged from -0.27 to 0.30 (p>0.05). Conclusion: Margin fit parameters and microleakage showed no strong correlations; cast crowns cemented with RMGI and RC had lower microleakage scores than ZP cement.

Marginal adaptation of CAD/CAM zirconia-based crown during fabrication steps

“…The assessment of the marginal adaptation was performed on extracted human molars which have been also used in previous studies [15,45] because their modulus of elasticity, bonding characteristics, thermal conductivity and strength are closer to the clinical situation rather than those of metal, plastic and animal teeth. The teeth were stored in thymol solution to prevent them from drying out and thereby becoming brittle, and inhibit the microbial activity [6].…”

Vertical discrepancy and microleakage of laser-sintered and vacuum-cast implant-supported structures luted with different cement types

“…31 The significance level was set at a = 0.05 for all statistical tests. [29][30][31] All data analyses were made with SPSS/PC+ v.17.0 (SPSS Inc., Chicago, IL, USA) statistical software.…”

Microleakage around zirconia crown margins after ultrasonic scaling with self‐adhesive resin or resin modified glass ionomer cement

“…A 2013 survey by Clinician's Report found that 55% of dentists use RMGI cement and 39% of dentists use a resin cement for zirconia crowns . Several in vitro studies have shown increased microleakage, as measured by dye penetration, around margins of crowns cemented with RMGI cements than resin cements . In contrast, an in vitro study reported less bacterial microleakage in crowns cemented with RMGI cement than resin cement…”

“…An i n vitro study found more adverse effects on surface roughness of resin‐based restorative materials using magnetostrictive ultrasonic scalers than sonic scalers . Piezoelectric ultrasonic scalers are clinically favorable due to their quieter operation, smaller tips and handpieces, and ease of use . It is possible that the vibrational forces produced by piezoelectric ultrasonic scalers may disrupt the bond formed at the crown margin.…”