Browsing by Autor "Pablo J. Atria"

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A minimally invasive approach to osseo-disintegrate implants via thermal energy. An in-vivo pilot stilly
(KU Leuven, 2021) R. Silva; M.L. Meyer; Felipe Cáceres; Pablo J. Atria; Marc Quirynen
status: Published
Assessment of cuspal deflection and volumetric shrinkage of different bulk fill composites using non-contact phase microscopy and micro-computed tomography
(Japanese Society for Dental Materials and Devices, 2018) Martin Prager; Mark C. Pierce; Pablo J. Atria; Camila S. Sampaio; Eduardo Cáceres; Mark S. Wolff; Marcelo Giannini; Ronaldo Hirata
The understanding of cuspal deflection and volumetric shrinkage of resin composites is necessary to assess and improve the placement techniques of resin-based materials. The aim of this study was to investigate the cuspal deflection and its relationship with volumetric polymerization shrinkage of different bulk-fill resin composites. The investigation was conducted using non-contact phase microscopy and micro-computed tomography. Thirty custom-milled aluminum blocks were fabricated for microscopy analysis and thirty-six tooth models with standardized Class I cavities were used for micro-computed tomography analysis. Results showed that high-viscosity composites present higher cuspal deflection compared to bulk-fill composites. The filler loading of resin composites seems to have an effect on cusp deflection, since the higher the filler content percentage, the higher the cusp deflection. On the other hand, it seems to have an opposite effect on volumetric shrinkage, since higher filler loadings produced lower volumetric shrinkage percentages.
Micro-computed tomography evaluation of volumetric polymerization shrinkage and degree of conversion of composites cured by various light power outputs
(Japanese Society for Dental Materials and Devices, 2017) Pablo J. Atria; Camila S. Sampaio; Eduardo Cáceres; Jessica Fernández; André Figueiredo Reis; Marcelo Giannini; Paulo G. Coelho; Ronaldo Hirata
This study evaluated the influence of different light-curing modes on the volumetric polymerization shrinkage and degree of conversion of a composite resin at different locations using micro-computed tomography and Fourier transform infrared spectroscopy (FTIR). Specimens were divided into 4 groups based on the light-curing mode used (Bluephase 20i): 1 -High (1,200 mW/cm2); 2 -Low (650 mW/cm2); 3 -Soft-start (650-1,200 mW/cm2); and 4 -Turbo (2,000 mW/cm2). Degree of conversion was calculated by the measurement of the peak absorbance height of the uncured and cured materials at the specific wavenumbers, and was performed by FTIR 48 h after curing resin samples. Degree of conversion was analyzed using two-way ANOVA. No significant differences were observed independent of the region of the restoration investigated (p>0.05). Different curing modes did not influence volumetric shrinkage neither degree of conversion of class I composite resin restorations.