ABSTRACT
Introduction: The aim of this study was to evaluate the influence of metal oxides from investment dies on the color of metal‑free VM7 ceramic. Materials and Methods: Forty circular patterns were made with an elastic gelatin duplicator. These were divided into four groups (n = 10) for pouring the investment: G1, Begoform (Bego); G2, Ducera Lay Superfit (DeguDent GmbH); G3, Duravest (Polidental), and G4, Refrax Magnum (CNG). Refractory dies were subjected to the degassing process for gas and metal oxide elimination, and the testing was done with the application of two layers of VM7 ceramic. These layers were sinterized in accordance with the manufacturer’s recommendation and then glazed. For the control group, 10 additional VM7 ceramic discs were made without the use of any investment die. The ceramic’s control color and the tested groups were analyzed with the aid of a portable colorimeter (Minolta CR‑10) in the CIELab. The color change (ΔE) of the specimens from the tested groups was obtained, and the data were submitted to one‑way ANOVA and post‑hoc Tukey’s test. Results: All tested groups had a color change from the control group. G1 (5,3) and G2 (5,3) were those that showed the greater color change and did not show statistical differences between themselves; G3 (3,3) and G4 (3,1) were those that showed the least color change from control group and did not show statistical differences between themselves. Conclusion: Once all investments present a perceptible color change from the control group, color selection should be done with a laboratory‑produced color scale.
Subject(s)
Ceramics/chemistry , Dental Materials/chemistry , Dental Porcelain/chemistryABSTRACT
Lesões periradiculares ocorrem em dentes não vitais como resultado de uma agressão crônica devido a presença de microrganismos dentro do canal radicular, as quais podem ser observadas como uma lesão radiolúcida durante o exame radiográfico; o tratamento varia de acordo com métodos cirúrgicos ou não-cirúrgicos. Este reporte de caso descreve a regressão de uma lesão periapical grande usando um tratamento endodôntico não-cirúrgico em associação com medicação intracanal à base de hidróxido de cálcio. Após exame do paciente e análise radiográfica, uma lesão radiolúcida com 13 mm (no maior diâmetro) foi observada no dente número 12. O tratamento endodôntico foi realizado e Calen-CMCP (S.S. White Artigos Dentários Ltda., Rio de Janeiro, RJ, Brazil) foi aplicado dentro do canal, o qual foi substituído por nova medicação a cada 2 semanas durante 2 meses. A lesão regrediu progressivamente a partir de cada troca de medicação. Além disso, após acompanhamento de 6 anos o dente permaneceu livre de infecção e o tecido ósseo foi completamente regenerado. Conclui-se que terapia à base de hidróxido de cálcio pode estimular de maneira conservadora a regressão de lesões periapicais grandes...
Periradicular lesions occur in non-vital teeth as the result of a chronic aggression by the presence of microorganisms into the root canal, which may appear as a radiolucent lesion in the radiographic exam; treatment varies according to surgical or nonsurgical methods. This case report describes the regression of a periradicular lesion using a nonsurgical endodontic treatment in association with intracanal calcium hydroxide-based medicament. After patient examination and radiographic analysis, a 13 mm (in maximum diameter) radiolucent lesion was observed in tooth number 12. The endodontic treatment was done and Calen-CMCP (S.S. White Artigos Dentários Ltda., Rio de Janeiro, RJ, Brazil) was placed into the root canal, which was changed after every two weeks during two months. It was observed a progressive centrifugal regression of the lesion after every renewing of the medicament. In addition, after six-year follow-up the tooth was still free of re-infection and bone tissue was completely regenerated. In conclusion, calcium hydroxide therapy can conservatively stimulate the regression of large periradicular lesions...