Effect of storage time and composite thickness on Degree of Conversion of Bulk-fill and universal composites using FTIR method / Efeito do tempo de armazenamento e da espessura no grau de conversão de compósitos Bulk-fill e universais usando o método FTIR

Objective: Degree of Conversion (DC) of ResinBased composites (RBCs) is a concern and is affected by different factors. This study was conducted to evaluate the effect of different thicknesses and storage times on DC of bulk-fill and universal RBCs using the FTIR method. Material and Methods: For each of dental composite (Tetric N- Ceram Bulk Fill and Tetric N Ceram), 28 samples were prepared (14 samples with 2 mm height and 14 samples with 4 mm height). One and seven days (1d and 7d) after storage in an incubator at 37 ˚C, DC was measured and recorded using a FTIR device. Data were analyzed using t-test and ThreeWay ANOVA and Tukey Post-Hoc Test. P < 0.05 was considered statistically significant. Results: DC of Bulk-fill composite is greater than universal composite. DC at 2 mm thickness is more than 4 mm. Unlike universal composite, 7d DC of Bulkfill composite is greater than 1d. Of course, none of these differences are statistically significant (P-value > 0.05). Conclusion: Considering the limitation of this study, since no difference was found between DC of 1d and 7d, 1d DC is sufficient for clinical procedures, such as polishing, and the laboratory tests. (AU)

Objetivo: O grau de conversão (DC) de compósitos à base de resina (RBCs) é um assunto que merece cuidado e é afetado por diferentes fatores. Este estudo foi conduzido para avaliar o efeito de diferentes espessuras e tempos de armazenamento no DC de compósitos Bulk-fill e compósitos universais usando o método FTIR. Material e Métodos: Para cada compósito dentário (Tetric N-Ceram Bulk Fill e Tetric N Ceram), foram preparadas 28 amostras (14 amostras com 2 mm de altura e 14 amostras com 4 mm de altura). Um e sete dias (1d e 7d) após o armazenamento em uma incubadora a 37 ° C, o DC foi mensurado e registrado usando um dispositivo FTIR. Os dados foram analisados por meio do teste t, ANOVA três fatores e teste PostHoc de Tukey. P 0,05). Conclusão: Considerando a limitação deste estudo, uma vez que não foi encontrada diferença entre as DC de 1d e 7d, a 1d DC é suficiente para procedimentos clínicos, como polimento e testes laboratoriais. (AU)

Comparison of the efficacy of calcium versus acetaminophen on reduction of orthodontic pain.

Background: Pain and discomfort are common during orthodontic treatment. Aim: The aim of this single blind clinical trial was to compare the effectiveness of oral calcium versus acetaminophen in pain reduction. Materials and Methods: In this study, the patients recorded their pain on a 100-mm visual analogue scale (VAS). Forty female patients (14-19 years old) who had passed at least 2 months of their first orthodontic archwire placement and their pain intensity was 40-100 mm (VAS) were selected and randomly assigned to two groups. Psychotic status was measured using Hospital Anxiety and Depression Scale (HADS). In group 1 calcium forte tablets (500 mg) and in group 2 acetaminophen (325 mg) tablets were prescribed to be taken one tablet per day. After consumption of all tablets (n=60), pain intensity was measured and compared with that before drug therapy. Results: The results indicated that the difference in pain intensity before and after drug administration in the calcium group was statistically significant (P<0.001), but not significant in the acetaminophen group (P=0.468). The difference between the pain reduction in the two groups were also statistically significant (P<0.001). In the calcium group 9.5% and in the acetaminophen group 15.8% had anxiety that was not statistically significant (P=0.631). In both groups, no subject had depression. Conclusion: Calcium is more effective than acetaminophen in long-term pain reduction during orthodontic treatment.