Effects of ultrasonic and sonic scaling on surfaces of tooth‑colored restorative materials: An in vitro study

Objective: The effects of sonic and ultrasonic scalings (USSs) on the surface roughness of nanohybrid, flowable, and polyacid-modified resin composites and conventional glass ionomer cement were examined, and the effectiveness of repolishing on the scaled material surfaces was determined.Materials and Methods: The surface roughness of each sample was measured three times before and after each scaling and after repolishing, and the data were analyzed using repeated measuresanalysis of variance, Tukey’s multiple comparisons, and paired t-tests by a statistical program.Results: Although sonic and USS both significantly increased the surface roughness of all the tooth-colored materials, USS roughened the surfaces of all the test materials more than SS did. Hence, USS may detrimentally affect tooth-colored restorative materials, especially conventional glass ionomers and compomers. Repolishing decreased the surface roughness of all the materials to near their baseline levels.Conclusions: On the basis of these results, the repolishing of restoration surfaces is strongly recommended after dental scalings.Keywords: Repolishing, sonic scaling, tooth‑colored dental materials, ultrasonic scalin

Employee Stock Ownership and Financial Performance in European Countries: The Moderating Effects of Uncertainty Avoidance and Social Trust

This study investigates how the effect of employee stock ownership on financial performance may hinge on the diverse cultural and societal contexts of European countries. Based on agency and national culture theories, we hypothesize that the positive relationship between employee stock ownership and return on assets (ROA) is stronger in those nations with lower uncertainty avoidance and higher social trust. Using a multisource, time‐lagged, large‐scale dataset of 1,741 firms from 21 countries in Europe, our multilevel, random coefficient modeling analysis found evidence for these hypotheses, suggesting that uncertainty avoidance and social trust serve as important contextual cues in predicting the linkage between employee stock ownership and financial performance. Our supplemental analysis with distinction between the managerial and nonmanagerial employee stock ownership further indicates managerial employee stock ownership has a direct positive effect on ROA. Although nonmanagerial employee stock ownership had a nonsignificant association with ROA, the relationship was positive and significant when uncertainty avoidance was low and social trust was high. This research contributes to the existing literature by illuminating some of the contextual influences altering the effectiveness of employee stock ownership. Our findings also offer practical suggestions for effectively using employee stock ownership

A comparative study of two fissure sealants: a 2-year clinical follow-up

The aim of the study was to compare the fluoride-containing fissure sealants (Helioseal F) with the conventional (Concise Light Cure White Sealant) fissure sealants in their retention and caries-prevention capabilities in young population. Sealant materials were applied by three dentists on 122 fissures of first and second molars in 59 adults, 18-20 years of age. One hundred and twenty-two non-carious and unsealed molar teeth were selected as controls. The teeth were assessed using the following criteria: 1 - fully retained (FR), 2 - partially lost (PL), 3 - totally lost (TL) and 4 - decayed (D). All teeth were clinically assessed at 3, 6, 12 and 24 months by two examiners who were blinded to the sealant materials. Data were statistically analysed with chi-square tests. After 3 months 72.1% of sealants were fully retained, at 24 months this had dropped to 46.7%. The partial loss of sealants was at 3 months (15.6%), 6 months (26.2%), 12 months (27.9%) and 24 months (27%). The total loss of Helioseal F (16.4, 19.7, 18, 23% at 3rd, 6th, 12th and 24th months, respectively) was more than the total loss of Concise Light Cure White Sealant (8.2, 9.8, 11.5, 18%, respectively); meaning that the retention rate of Helioseal F was lower than for Concise Light Cure White Sealant. No caries was detected at 3rd and 6th months in all sealant-treated teeth. The incidence of caries in Helioseal F treated teeth at 12 and 24 months was 11.5% and 0% in Concise Light Cure White Sealant treated teeth. The incidence of caries in all fissure-sealant-treated-teeth after 24 months was 5.7 and 25.4% in control group. The results underline that the application of fissure sealants to young people in this sample is an effective method for the prevention of fissure caries

Effects of ultrasonic and sonic scaling on surfaces of tooth-colored restorative materials: An in vitro study

Objective: The effects of sonic and ultrasonic scalings (USSs) on the surface roughness of nanohybrid, flowable, and polyacid-modified resin composites and conventional glass ionomer cement were examined, and the effectiveness of repolishing on the scaled material surfaces was determined

A comparative study of two fissure sealants: a 2-year clinical follow-up

The aim of the study was to compare the fluoride-containing fissure sealants (Helioseal F) with the conventional (Concise Light Cure White Sealant) fissure sealants in their retention and caries-prevention capabilities in young population. Sealant materials were applied by three dentists on 122 fissures of first and second molars in 59 adults, 18-20 years of age. One hundred and twenty-two non-carious and unsealed molar teeth were selected as controls. The teeth were assessed using the following criteria: 1 - fully retained (FR), 2 - partially lost (PL), 3 - totally lost (TL) and 4 - decayed (D). All teeth were clinically assessed at 3, 6, 12 and 24 months by two examiners who were blinded to the sealant materials. Data were statistically analysed with chi-square tests. After 3 months 72.1% of sealants were fully retained, at 24 months this had dropped to 46.7%. The partial loss of sealants was at 3 months (15.6%), 6 months (26.2%), 12 months (27.9%) and 24 months (27%). The total loss of Helioseal F (16.4, 19.7, 18, 23% at 3rd, 6th, 12th and 24th months, respectively) was more than the total loss of Concise Light Cure White Sealant (8.2, 9.8, 11.5, 18%, respectively); meaning that the retention rate of Helioseal F was lower than for Concise Light Cure White Sealant. No caries was detected at 3rd and 6th months in all sealant-treated teeth. The incidence of caries in Helioseal F treated teeth at 12 and 24 months was 11.5% and 0% in Concise Light Cure White Sealant treated teeth. The incidence of caries in all fissure-sealant-treated-teeth after 24 months was 5.7 and 25.4% in control group. The results underline that the application of fissure sealants to young people in this sample is an effective method for the prevention of fissure caries