Final Colour of Ultratranslucent Multilayered Zirconia Veneers, Effect of Thickness, and Resin Cement Shade.

Background: Aesthetic restorations should be able to mimic the natural colour depth of teeth, affected by several factors including material properties. There is a lack of information regarding the effect of cement shade and material thickness on the final colour of ultratranslucent multilayered zirconia veneers. Objectives: This study evaluated the effect of ceramic thickness and resin cement shade on the final colour of different layers of ultratranslucent multilayered (UTML) zirconia veneers. Methods: This in vitro study produced 90 rectangular-shaped specimens with nonsintered Katana UTML monolithic zirconia (Kuraray Noritake Dental, Tokyo, Japan), shade A1 blocks. Ceramic samples were prepared in two groups of 0.7 mm and 0.5 mm thicknesses, 45 of each (a: 8 × 11 × 0.5 mm; b: 8 × 11 × 0.7 mm). Specimens of each thickness were further divided into 5 groups: universal, clear, brown, white, and opaque (n = 9). Each adhesive resin cement (Panavia V5) was applied between the ceramic samples and composite substrate. The colour values were measured using a spectrophotometer in baseline and after resin cement application according to the CIELab system. For all samples, ΔE00 values were obtained. Data were evaluated with SPSS 25 using the three-way ANOVA test (p < 0.05). Results: The factors of cement shade, ceramic thickness, and ceramic layers have statistically significant effect on ΔE00 values (p < 0.001). The results showed lower ΔE00 values with thicker ceramic veneers. Tukey test results showed that the opaque and brown shade had a significantly greater ΔE00 values comparing to universal (p = 0.004), clear, and white shades (p < 0.001). Conclusion: The colour change was greater in lower ceramic thickness. Different shades of resin cement and layers of UTML zirconia differently affected the final colour.

The Influence of Parenting Style and Child Temperament on Child-Parent-Dentist Interactions.

PURPOSE: This study aimed to investigate the interaction between parenting style and child's temperament as modulators of anxiety and behavior in children during the dental procedure. METHODS: Healthy four- to six-year-olds (n equals 288), with carious primary molars scheduled to receive amalgam fillings were selected. The Primary Caregivers Practices Report was used to assess the parenting style, and the Children's Behavior Questionnaire-Very Short Form was used to evaluate child temperament. Children were managed using common behavior management strategies. Child behavior and anxiety during the procedure were assessed using the Frankl behavior rating scale and the verbal skill scale, respectively. Spearman's correlation coefficient was used to examine the correlation among variables. RESULTS: Authoritative parenting style was positively related to positive child's behavior (P<.05) and negatively related to child's anxiety (P<.05). A positive relationship existed between permissive subscale and negative behaviors (P<.05) and child's anxiety (P<.05). There was a significant direct effect of authoritative parenting style on the effortful control trait (P<.05) and permissive parent style on the child negative affectivity (P<.05). CONCLUSIONS: Parenting style appeared to mediate child temperament and anxiety, and was related to the child's behavior. Parenting style should be considered in the selection of behavior guidance techniques.