RESUMO
BACKGROUND: Given that obesity and insulin resistance play key roles in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and the connection between leptin and these metabolic diseases, the association between NAFLD and a leptin receptor gene (LEPR) polymorphism was examined. METHODS: In this genetic case-control association study, 144 biopsy-proven NAFLD patients and 144 controls were genotyped for the LEPR gene Gln223Arg (rs1137101) polymorphism using the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: The distributions of genotypes and alleles of Gln223Arg variant were in accordance with the Hardy-Weinberg equilibrium in the study groups (P > .05). Multivariate logistic regression analysis showed that the LEPR Gln223Arg Arg/Arg genotype was an independent risk factor for NAFLD; the Arg/Arg genotype, compared with the Gln/Gln genotype, was associated with a 2.09-fold increased risk for NAFLD (P = .036, odds ratio = 2.09 [95% CI = 1.31-5.95]). CONCLUSIONS: We found that the LEPR Gln223Arg Arg/Arg genotype was independently associated with a more than 2-fold rise in biopsy-proven NAFLD risk. Our findings, however, need to be corroborated by further studies.
RESUMO
PURPOSE: The metal framework of implant-supported restorations can be made using different methods. For a successful outcome, the acceptability of each method depends on the retention and fit of the restoration. The aim of this study was to evaluate and compare the retention and adaptation of copings fabricated using two methods: casting wax patterns made by computer-aided design/computer-aided manufacturing (CAD/CAM) technology, and milling sintered chromium-cobalt (Cr-Co) blocks. MATERIALS AND METHODS: Twenty-four abutment analogs (height, 5.5 mm) were divided into two groups according to the framework fabrication method. In one group, wax patterns were prepared using a CAM milling machine, and they were cast with a Ni-Cr-Ti metal alloy. In the second group, the copings were milled from Cr-Co blocks using a CAD/CAM milling machine. All copings were equal in contour, thickness, and internal relief and were seated on the abutment analogs after the necessary adjustments. The vertical marginal discrepancy was investigated using a silicone replica method and stereomicroscope with 75× magnification. After copings were cemented onto the abutment analogs using zinc phosphate, a tensile resistance test was performed using a universal testing machine. Mann-Whitney U and Student's t-test were used for statistical analyses at a significance level of 0.05. RESULTS: An independent sample t-test revealed a significant difference between the two groups for retention (p = 0.010), and the milled wax group showed higher tensile resistance compared with the milled metal group. There was also a significant difference between the two groups in marginal discrepancy (p < 0.001), with a larger marginal gap in the milled metal group compared with the milled wax group. The milled metal copings required more adjustments to fit on the abutment analogs compared with the wax milled copings (p < 0.001). CONCLUSIONS: The CAD/CAM technique for wax milling resulted in more retentive copings with better marginal and internal adaptations compared with milling the metal blocks.
