Y Nakaoki1, T Nikaido, P N Pereira, S Inokoshi, J Tagami. 1. Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, 5-45 Yushima 1-chome, Bunkyo-ku, Tokyo 113-8549, Japan.
Abstract
OBJECTIVES: The purpose of this study was to measure the dimensional changes of demineralized dentin before and after application of HEMA (2-hydroxyethyl methacrylate) by confocal laser scanning microscopy (CLSM). METHODS: The middle portion of bovine dentin was ground, polished, and covered with a vinyl tape with a 4-mm hole punched through it. A strip of polysiloxane impression material was then placed across the center of the dentin surface to preserve a strip of the original unetched surface. Dentin surfaces were etched with 32% phosphoric acid for 60 s and rinsed with water. The impression material was then removed and the following sequential steps were performed: the dentin surface was mildly air-dried, then strongly air-dried, then treated with either 35 wt.% HEMA/water or 100 wt.% HEMA and mildly air-dried, and then strongly dried again. The shrinkage of the demineralized dentin surface from the original unetched level was measured by CLSM in each step and results analyzed by one-way ANOVA. RESULTS: The dimensional changes of demineralized dentin after mild air drying were approximately -1 micron and, following strong air drying, resulted in -5 microns shrinkage. Following the application of 35 wt.% HEMA/water, the height of the demineralized dentin changed to a level of -3.3 microns, but then shrank to -4.8 microns after strong drying. ANOVA indicated that re-expansion of the shrunken etched dentin was significant (p < 0.05); however, the treated surface collapsed when it was strongly dried again (p < 0.05). 100% HEMA did not re-expand the shrunken demineralized dentin under any of the application on protocols (p > 0.05). SIGNIFICANCE: Thirty-five wt.% HEMA in water re-expanded the collapsed demineralized dentin matrix, however not to the original level. One hundred wt.% HEMA did not cause any re-expansion.
OBJECTIVES: The purpose of this study was to measure the dimensional changes of demineralized dentin before and after application of HEMA (2-hydroxyethyl methacrylate) by confocal laser scanning microscopy (CLSM). METHODS: The middle portion of bovine dentin was ground, polished, and covered with a vinyl tape with a 4-mm hole punched through it. A strip of polysiloxane impression material was then placed across the center of the dentin surface to preserve a strip of the original unetched surface. Dentin surfaces were etched with 32% phosphoric acid for 60 s and rinsed with water. The impression material was then removed and the following sequential steps were performed: the dentin surface was mildly air-dried, then strongly air-dried, then treated with either 35 wt.% HEMA/water or 100 wt.% HEMA and mildly air-dried, and then strongly dried again. The shrinkage of the demineralized dentin surface from the original unetched level was measured by CLSM in each step and results analyzed by one-way ANOVA. RESULTS: The dimensional changes of demineralized dentin after mild air drying were approximately -1 micron and, following strong air drying, resulted in -5 microns shrinkage. Following the application of 35 wt.% HEMA/water, the height of the demineralized dentin changed to a level of -3.3 microns, but then shrank to -4.8 microns after strong drying. ANOVA indicated that re-expansion of the shrunken etched dentin was significant (p < 0.05); however, the treated surface collapsed when it was strongly dried again (p < 0.05). 100% HEMA did not re-expand the shrunken demineralized dentin under any of the application on protocols (p > 0.05). SIGNIFICANCE: Thirty-five wt.% HEMA in water re-expanded the collapsed demineralized dentin matrix, however not to the original level. One hundred wt.% HEMA did not cause any re-expansion.
Authors: Roberta Pimentel de Oliveira; Brennda Lucy de Paula; Mara Eliane Ribeiro; Eliane Alves; Hilton Túlio Costi; Cecy Silva Journal: Int J Dent Date: 2022-06-10
Authors: Shariq Najeeb; Zohaib Khurshid; Muhammad Sohail Zafar; Abdul Samad Khan; Sana Zohaib; Juan Manuel Nuñez Martí; Salvatore Sauro; Jukka Pekka Matinlinna; Ihtesham Ur Rehman Journal: Int J Mol Sci Date: 2016-07-14 Impact factor: 5.923