Influence of Hemostatic Solution on Bond Strength and Physicochemical Properties of Resin Cement

Abstract The aim of this study was to evaluate the degree of conversion, color stability, chemical composition, and bond strength of a light-cured resin cement contaminated with three different hemostatic solutions. Specimens were prepared for the control (uncontaminated resin cement) and experimental groups (resin cement contaminated with one of the hemostatic solutions) according to the tests. For degree of conversion, DC (n = 5) and color analyses (n = 10), specimens (3 mm in diameter and 2 mm thick) were evaluated by Fourier transform infrared spectroscopy (FTIR) and CIELAB spectrophotometry (L*, a*, b*), respectively. For elemental chemical analysis (n = 1), specimens (2 mm thick and 6 mm in diameter) were evaluated by x-ray energy-dispersive spectroscopy (EDS). The bond strengths of the groups were assessed by the microshear test (n = 20) in a leucite-reinforced glass ceramic substrate, followed by failure mode analysis by scanning electron microscopy (SEM). The mean values, except for the elemental chemical evaluation and failure mode, were evaluated by ANOVA and Tukey's HSD test. The color stability was influenced by storage time (p<0.001) and interaction between contamination and storage time (p<0.001). Hemostop and Viscostat Clear contamination did not affect the DC, however Viscostat increased the DC. Bond strength of the resin cement to ceramic was negatively affected by the contaminants (p<0.001). Contamination by hemostatic agents affected the bond strength, degree of conversion, and color stability of the light-cured resin cement tested.

Resumo O objetivo desse estudo foi avaliar o grau de conversão, estabilidade de cor, composição química e resistência de união de um cimento resinoso fotoativado contaminado com três soluções hemostáticas diferentes. Foram preparadas amostras para o grupo controle (cimento não contaminado) e grupos experimentais (cimento contaminado com uma das soluções hemostáticas) de acordo com os testes. Para o grau de conversão e análise de cor (n=10), as amostras (3 mm de diâmetro e 2 mm de espessura) foram avaliadas por espectroscopia de infravermelho com transformação de Fourier (FTIR) e espectrofotometria CIELAB (L*, A*, B*), respectivamente. Para a análise química elementar (n=1), os espécimes (2 mm de espessura e 6 mm de diâmetro) foram avaliados por espectroscopia de energia dispersiva de raios-x (EDS). As resistências de união dos grupos foram avaliadas pelo ensaio de microcisalhamento (n=20) em um substrato cerâmico de vidro reforçado com leucita, seguida da análise de modo de falha por microscopia eletrônica de varredura (MEV). Os valores médios, com exceção da avaliação química e do modo de falha, foram avaliados por ANOVA e pelo teste de Tukey. A estabilidade de cor foi influenciada pelo tempo de armazenagem (p<0,001) e interação entre a contaminação e o tempo (p<0,001). A contaminação pelo Hemostop e Viscostat Clear não influenciaram no GC, porém a contaminação com Viscostat aumentou o GC. A resistência de união do cimento a cerâmica foi negativamente afetada pelos contaminantes (p<0,001). A contaminação por agentes hemostáticos afetou a resistência de união, o grau de conversão e a estabilidade de cor do cimento resinoso fotoativado testado.

Tooth color changes associated with the bracket bonding and debonding / 대한치과교정학회지

The purpose of this study was to evaluate the tooth color changes of resin bonding sites and their adjacent sites on orthodontic bracket bonding. Sixty extracted sound premolars were used and the tooth color was recorded according to the CIE L(*)a(*)b(*) color system using a spectrophotometer. The tooth colors of the twenty premolars were measured and compared before bracket bonding and after removal. On a further twenty premolars, the tooth color was measured before and after only primer application. In the change of L(*) values, according to the bracket bonding and primer application, the lightness was decreased, and in the change of a(*) and b(*) values, the color was changed into a more yellowish color. The color differences (delta E(*)) were calculated from the L(*)a(*)b(*) values and compared with the standard value of clinical detection (delta E(*)=3.7). The color differences between before the bracket bonding and after removal noted exceeded the standard value and those of between before and after the primer application were not larger than the standard value. Toothbrushing was performed after application of the primer to evaluate the color changes according to the primer abrasion. As a control, toothbrushing was performed on the last twenty premolars. The color differences noted were larger than the standard value after toothbrushing. Also, to evaluate the color changes of the tooth which is exposed to sun irradiation after bracket removal, additional photoaging was performed and the color was measured for all teeth. The additional color differences after photoaging were smaller than the standard value. The above results suggest that the tooth color changes after fixed orthodontic treatment.