Demarco F F, Freitas J M, Silva M P, Justino L M
Department of Operative Dentistry, Faculty of Dentistry, Federal University of Pelotas, RS, Brazil.
Int Endod J. 2001 Oct;34(7):495-500. doi: 10.1046/j.1365-2591.2001.00418.x.
The purpose of the present study was to evaluate microleakage of a fourth generation dentine-bonding agent and composite restoration during a walking bleach treatment.
Thirty extracted non-carious incisors were selected and conventional root canal treatment was performed. Teeth were randomly divided into 3 groups (n = 10): group A (control), access cavities were restored with a fourth generation dentine-bonding agent, and incrementally restored with composite resin; group B, a paste composed of sodium perborate and hydrogen peroxide was placed into the pulp chamber and sealed with glass ionomer cement for 7 days, teeth were then restored in the same manner as group A; group C, a paste of sodium perborate and hydrogen peroxide was placed in the pulp chamber for 7 days and then after removal of the bleaching mixture, pulp chambers were filled with a calcium hydroxide paste and cavities sealed with glass ionomer for 1 week. The cavities were then restored with bonded restorations as in groups A and B. Teeth were subjected to thermal cycling and immersed in methylene blue for 8 h. Teeth were sectioned from buccal to lingual, through the centre of the restoration, using a diamond disk. Leakage was assessed using a standard scheme, under magnification (x20). Data were submitted to statistical analysis using nonparametric Kruskal-Wallis test.
Groups A and C exhibited similar leakage patterns, and both demonstrated less leakage values than group B (P < 0.05).
It was concluded that bleaching with sodium perborate and hydrogen peroxide increases microleakage; short-term use of a calcium hydroxide medicament did not increase microleakage.
本研究旨在评估在进行牙齿漂白术期间，第四代牙本质粘结剂和复合树脂修复体的微渗漏情况。
选取30颗拔除的无龋切牙，进行常规根管治疗。将牙齿随机分为3组（每组n = 10）：A组（对照组），用第四代牙本质粘结剂修复髓腔入口，并用复合树脂分层修复；B组，将由过硼酸钠和过氧化氢组成的糊剂置于髓腔内，并用玻璃离子水门汀密封7天，然后以与A组相同的方式修复牙齿；C组，将过硼酸钠和过氧化氢糊剂置于髓腔内7天，然后去除漂白混合物后，髓腔内填充氢氧化钙糊剂，并用玻璃离子封闭窝洞1周。然后像A组和B组一样用粘结修复体修复窝洞。对牙齿进行热循环处理，并浸入亚甲蓝中8小时。使用金刚石圆盘从颊侧到舌侧通过修复体中心将牙齿切片。在放大20倍的情况下，使用标准方案评估渗漏情况。数据采用非参数Kruskal-Wallis检验进行统计分析。
A组和C组表现出相似的渗漏模式，且两者的渗漏值均低于B组（P < 0.05）。
得出的结论是，用过硼酸钠和过氧化氢进行漂白会增加微渗漏；短期使用氢氧化钙药物不会增加微渗漏。
