ABSTRACT
Aim: The aim of this study is to evaluate the effect of different doses of the ionizing radiation (0 Gy, 10 Gy, 30 Gy, and 60 Gy) on the physical properties of dental materials. Methodology: Disc-shaped samples from each material (Ketac Molar Easymix, Vitro Molar, Vitremer, Vitro Fil Lc, Filtek Z 250 and Filtek Z 350) were made for water solubility, sorption analysis (n = 20), microhardness (n = 20), and surface roughness analysis (n = 24). Specimens were divided into four groups, according to radiation dose: control group (0 Gy), 10 Gy, 30 Gy, and 60 Gy. For water solubility and sorption analysis, the specimens were irradiated and were stored for 21 days to calculate the water solubility and sorption values. Microhardness analysis was carried out before and after irradiation doses. For surface roughness analysis, the specimens were submitted to brushing test, and after 24 h, initial surface roughness analysis was made in a rugosimeter. Subsequently, the samples were irradiated and final surface roughness analysis was made. The original water solubility and sorption, surface roughness, and microhardness values were subjected to ANOVA two-way statistical analysis and Paired t-test and Tukey post hoc test (α = 0.05), respectively. Results: Water solubility and sorption values, and surface roughness values presented statistical difference between groups (0, 10, 30 e 60 Gy) for all materials. Conclusions: High doses of ionizing radiation (30 Gy and 60 Gy) increased the surface roughness, sorption, and solubility for the most materials.
ABSTRACT
Objective: To evaluate the impact of radiotherapy on enamel around restorations of glass ionomer cement (GIC) and fluoride tooth paste (FTP). Material and Methods: Eighty enamel blocks were made and randomly distributed into two groups, according to the fluoride therapy, non-fluoride tooth paste (NFTP) and FTP (n=40) and in subgroups in conformity with radiation dose (0, 10, 30 and 60 Gy). Roughness and microhardness enamel analyses were conducted before radiotherapy. Enamel cavities were made and restored with two GIC (Ketac Molar Easy Mix or Vitremer). Enamel blocks were submitted to 10, 30 and 60 Gy. Then, artificial enamel caries lesions were created by a pH-cycling procedure and FTP or NFTP were used as treatment. The restored enamel blocks were submitted to final roughness and microhardness analyses. Roughness increase (ΔR) and hardness loss (ΔH) values of enamel were submitted to ANOVA and Tukey test (p=0.05). Results: The irradiated enamel group showed statistically higher ΔR (0.44 ±0.2) and ΔH (99.26±7.0) values compared to non-irradiated group (ΔR = 0.051±0.02; ΔH=66.16±12.7) when a resin-modified GIC and NFTP were used. Conclusion: Higher radiation dose increased dissolution of bovine enamel. The use of GIC associated with FTP decreased roughness and increased enamel hardness after radiotherapy.
Subject(s)
Radiotherapy/methods , Tooth Remineralization/adverse effects , In Vitro Techniques/methods , Dental Enamel , Glass Ionomer Cements/radiation effects , Brazil , Analysis of Variance , Hardness Tests/methodsABSTRACT
Objetivo: Avaliar a rugosidade do esmalte de dentes bovinos submetidos ao desafio erosivo por bebidas infantis, no intervalo de tempo de 07, 14 e 21 dias e a influência de dentifrício fluoretado após esses desafios erosivos. Métodos: Foram obtidos 40 espécimes de bloco de esmalte, os quais foram divididos aleatoriamente em 8 grupos de acordo com os tratamentos (n=5): G1 suco de maçã Ades®; G1F suco de maçã Ades® + dentifrício; G2 mel de abelha Yoki®; G2F mel de abelha Yoki® + dentifrício; G3 leite fermentado Chamyto®; G3F leite fermentado Chamyto® + dentifrício; G4 controle; G4F controle + dentifrício. Após a análise da rugosidade superficial inicial, os blocos de esmalte foram submetidos ao desafio erosivo. Para os grupos com tratamento com flúor, os espécimes foram imersos em dentifrício fluoretado diluído. Foram realizadas análises da rugosidade superficial após os períodos de 7, 14 e 21 dias. Os dados foram submetidos à análise estatística, empregando-se os testes de Friedman e Wilcoxon com 5% de probabilidade. Resultados: O grupo G2F e G2 apresentaram valores de rugosidade de superfície estatisticamente superiores (p=0,01) após 7 e 21 dias, respectivamente, em relação ao valores iniciais. Os valores de rugosidade de superfície para o grupo G3 (p=0,006) e G3F (p=0,01) foram superiores estatisticamente após 7 dias em relação ao período inicial. Conclusão: Os valores de rugosidade do esmalte aumentaram após o desafio erosivo com mel de abelha e o leite fermentado. O uso do dentifrício fluoretado não promoveu menor incremento de rugosidade.(AU)
Aim: To evaluate surface roughness of tooth enamel when submitted to erosive challenge from beverages after 07, 14 and 21 days as well as the influence of fluoride toothpaste on enamel surface roughness after the erosive challenges. Methods: Forty enamel blocks were made and divided into 8 groups according to treatment (n=5): G1 apple juice Ades ®; G1F apple juice Ades ® + fluoride toothpaste; G2 honey; G2F honey + fluoride toothpaste; G3 fermented milk Chamyto ®; G3F fermented milk Chamyto ® + fluoride toothpaste ; G4 control; G4F control + fluoride toothpaste. After initial analysis of surface roughness, specimens were submitted to erosive challenges. In the groups submitted to fluoride treatment, specimens were immersed in diluted fluoride toothpaste. Analysis of surface roughness was conducted after 7, 14 and 21 days. The values of average enamel roughness (Ra) in the experimental groups were submitted to Friedman and Wilcoxon test considering the significance level of 5%. Results: The G2 and G2F group presented statistically higher roughness values (p=0,01) compared to baseline, after 21 and 7 days, respectively. For G3 (p=0,006) and G3F group (p=0,01), roughness values were statistically higher after 7 days compared baseline. Conclusion: Enamel roughness values increased after erosive challenge with honey and fermented milk. Application of fluoride toothpaste did not promote lower roughness values.(AU)