Teixeira E C N, Hara A T, Turssi C P, Serra M C
Department of Restorative Dentistry, Piracicaba School of Dentistry, State University of Campinas, São Paulo, Ribeirão Peeto School of Dentistry, USP, São Paulo, Brazil.
J Oral Rehabil. 2003 Nov;30(11):1123-7. doi: 10.1046/j.1365-2842.2003.01161.x.
This study evaluated the effect of non-vital tooth bleaching on microleakage of composite resin/bovine tooth interface at different post-bleaching times. A total of 320 teeth were cleaned. A pulp chamber access cavity was made at the lingual surface of each tooth. The teeth were randomly divided into four groups: SPH - sodium perborate + 30% hydrogen peroxide; SPW - sodium perborate + distilled water; CP-37% carbamide peroxide; and CON-distilled water (control). The bleaching agents were replaced every 7 days, over 4 weeks. Following bleaching procedures, the groups were divided into four subgroups (n = 20), according to the post-bleaching times: 0 (baseline), 7, 14 and 21 days. After that, the cavities were restored with an adhesive system (Single Bond; 3M Co., St Paul, MN, USA) and a composite resin (Z100/3M). The specimens were thermocycled, stained with 2% methylene blue solution (pH 7), and sectioned longitudinally. The teeth were evaluated blind and independently by three previously calibrated examiners, to provide representative scores. The data were submitted to Kruskal-Wallis and multiple comparison tests (alpha=0.05). At baseline and 7 days, the SPH group showed a higher degree of dye penetration than the CON (P=0.04). At 14 and 21 days, there were no differences among groups. The association of sodium perborate with 30% hydrogen peroxide or with water may affect the sealing ability of composite resin restorations performed up to 7 days after bleaching procedures.
本研究评估了死髓牙漂白在不同漂白后时间对复合树脂/牛牙界面微渗漏的影响。总共320颗牙齿被清洁。在每颗牙齿的舌面制备一个髓腔进入洞。牙齿被随机分为四组：SPH组——过硼酸钠+30%过氧化氢；SPW组——过硼酸钠+蒸馏水；CP组——37%过氧化脲；以及CON组——蒸馏水（对照组）。漂白剂每7天更换一次，持续4周。漂白程序后，根据漂白后时间将各组再分为四个亚组（n = 20）：0天（基线）、7天、14天和21天。之后，用一种粘结系统（Single Bond；美国明尼苏达州圣保罗3M公司）和一种复合树脂（Z100/3M）修复窝洞。对标本进行热循环处理，用2%亚甲蓝溶液（pH 7）染色，然后纵向切片。由三名预先校准的检查者对牙齿进行盲法和独立评估，以给出代表性分数。数据进行Kruskal-Wallis检验和多重比较检验（α=0.05）。在基线和7天时，SPH组的染料渗透程度高于CON组（P = 0.04）。在14天和21天时，各组之间没有差异。过硼酸钠与30%过氧化氢或水联合使用可能会影响漂白程序后7天内进行的复合树脂修复体的封闭能力。
