An association of the MCP-1 and CCR2 gene polymorphisms with oral lichen planus.

OBJECTIVE: The purpose of this study was to investigate the frequency of monocyte chemoattractant protein (MCP)-1 CCR2 gene polymorphisms in Turkish patients with oral lichen planus (OLP). STUDY DESIGN: A cohort of 50 patients with OLP and 142 control participants without OLP were recruited to investigate the frequency of MCP-1 and CCR2 gene polymorphisms. Chi-square and Fisher's exact tests were used. Student t test and analysis of variance were used to compare demographic data between groups. RESULTS: The MCP AA genotype was less common in the patient group (52%) than in the control group (66.2%; odds ratio [OR] = 0.553; 95% confidence interval [CI], 0.287-1.065; P = .075). The MCP G allele was higher in the patient group (48%) than in the control group (33.8%; OR = 1.808; 95% CI, 0.939-3.479; P = .075). The frequency of the MCP GG genotype was observed to be higher in the patient group (4%) than in the controls (0.7%; OR: 5.875, 95% CI:0.521-66,24; p = 0.106). The CCR2 64I64I genotype was more common in the patient group (6%) than in the control group (2.8%). All results were not statistically significant. CONCLUSION: We suggest that the G allele of MCP-1 and 64I64I genotype of CCR2 polymorphisms do not pose an increased risk for Turkish patients with OLP to develop oral squamous cell carcinoma.

Comparison of retention forces with various fabrication methods and materials in double crowns.

PURPOSE: The purpose of this study was to analyze the retention force changes and wear behaviours of double-crown systems over long-term use. MATERIALS AND METHODS: Ten groups, each consisting of six samples, were evaluated. Specifically, casting gold alloy primary crown - casting gold alloy secondary crown (AA), laser sintering primary crown - laser sintering secondary crown (LL), casting Cr alloy primary crown - casting Cr alloy secondary crown, (CC) zirconia primary crown - electroformed secondary crown (ZA), and CAD/CAM titanium alloy primary crown - CAD/CAM titanium alloy secondary crown (TT) groups were evaluated at cone angles of 4° and 6°. The samples were subjected to 5,000 insertion-separation cycles in artificial saliva, and the retention forces were measured every 500 cycles. The wear levels were analyzed via SEM at the beginning and end of the 5,000 cycles. RESULTS: In all samples, the retention forces increased when the conus angle decreased. The highest initial and final retention force values were found in the LL-4° group (32.89 N-32.65 N), and the lowest retention force values were found in the ZA6° group (5.41 N-6.27 N). The ZA groups' samples showed the least change in the retention force, and no wear was observed. In the other groups, wear was observed mostly in the primary crowns. CONCLUSION: More predictable, clinically relevant, and less excursive retention forces can be observed in the ZA groups. The retention force values of the LL groups were statically similar to those of the other groups, except the ZA groups.