No abstract

All materials had radiopacity values above 3 mm of aluminium recommended by ANSI/ADA Specification 57.

Monowave and polywave LEDs emitted nonhomogeneous light beams, but this did not affect the DC homogeneity of bulk fill composites. For composites containing CQ associated with alternative photoinitiators, polywave LEDs had a higher DC, but only at the top part of the restoration; lower wavelength absorption photoinitiators were ineffective in deeper areas.

Aim The aim of this study was to evaluate the influence of immersion period in two disinfectant solutions on dimensional change of four elastomeric impression materials. Materials and methods Four representative materials of each class of elastomers: Xantopren (polydimethylsiloxane—PDS), Express (polyvinyl siloxane—PVS); Permlastic (polysulfide— PS) and Soft Impregum (polyether—EP) were mixed according to manufacturers’ instructions and then inserted into a metal matrix prepared according to the specification of ISO 4823. The molds were removed from the matrix after 7 minutes and immersed in disinfectant solutions (sodium hypochlorite 0.5 and 2% glutaraldehyde) for 5, 10, 20, 30 and 60 minutes (n = 7), except the control group, which was not immersed. Once removed from solutions, the test samples were washed in water for 15 seconds, dried and measured three times, using a comparative optical microscope, with accuracy of 0.0005 mm. The analysis of variance with three criteria and Tukey's test with significance level of 5% showed that differences in linear dimensions of the materials analyzed were not statistically significant (p > 0.05) after soaking in sodium hypochlorite 0.5 and 2% glutaraldehyde, for the tested periods of time. Clinical significance Combinations of molding material and disinfecting solution can be used in the dental clinic for infection control, without changing the dimensional molds, for immersion periods not longer than 20 minutes. How to cite this article Carvalhal CIO, de Mello JAN, Sobrinho LC, Correr AB, Sinhoreti MAC. Dimensional Change of Elastomeric Materials after Immersion in Disinfectant Solutions for Different Times. J Contemp Dent Pract 2011;12(4): 252-258.

Multiphasic calcium phosphate powders were synthesized by the acidic route, using lactic acid as a chelating agent that allows the production of a stable and rich solution of calcium and phosphate ions at room temperature. After pH adjusting, without varying the concentrations of precursor solution, XRD and FTIR analyses showed different CaP phases before and after heat treatment at 1000 °C. At pH 5, brushite plate-like particles were produced, while at higher pH levels (7 to 12) nano-hydroxyapatite particles were formed. After the calcination process, partial and total decomposition of hydroxyapatite in the β-TCP phase was explained by XRF analysis due to the calcium-deficient hydroxyapatite of synthesized samples at pH 7 and 10. This work presents an important method to synthesize any desired CaP phase compositions by varying the pH level and subsequently performing heat treatment, which has a direct effect on morphology, crystallinity, and formation of different CaP powders.