Weiger R, Kuhn A, Löst C
Department of Conservative Dentistry, School of Dental Medicine, University of Tübingen, Germany.
Int Endod J. 1994 Nov;27(6):313-7. doi: 10.1111/j.1365-2591.1994.tb00275.x.
The development of external cervical root resorption following internal bleaching of discoloured pulpless teeth is associated with the use of hydrogen peroxide. The aim of the study was to determine radicular penetration of hydrogen peroxide following intracoronal bleaching with various forms of sodium perborate. 63 extracted human incisors were root filled and stained artificially. Standardized cementum defects were created on the mesial and distal aspects of the root directly below the cemento-enamel junction (CEJ). Using the walking bleach technique all teeth were bleached for a 6-day period, with replacement of the bleaching paste after days 1 and 3. Sodium perborate monohydrate (MH), trihydrate (TRH) or tetrahydrate (TH) was mixed with H2O2 or H2O and subsequently placed intracoronally 1 mm below the labial CEJ. The teeth were divided into six groups: I. MH + H2O2(30%) (n = 12); II. TRH + H2O2(30%) (n = 12); III. TH + H2O2(30%) (n = 12); IV. TH + H2O (n = 12); V. TH + H2O, gel (n = 12); VI. no bleaching paste (n = 3). At baseline and at days 1, 3 and 6 the amount of H2O2 taken up from the surrounding medium of each root was indirectly recorded and calculated as p.p.m. Almost all teeth of the experimental groups showed leakage of hydrogen peroxide compared to those of the control group. The radicular penetration of hydrogen peroxide was significantly higher in teeth of groups I and III than in those of groups IV and V (P < or = 0.001). In conclusion, the amount of hydrogen peroxide leakage depends, among other factors, on the form of sodium perborate used.(ABSTRACT TRUNCATED AT 250 WORDS)
变色无髓牙内漂白后发生颈外牙根吸收与过氧化氢的使用有关。本研究的目的是确定使用各种形式的过硼酸钠进行冠内漂白后过氧化氢的根管渗透情况。63颗拔除的人切牙进行了根管充填并人工染色。在牙骨质-釉质界（CEJ）正下方的牙根近中和远中面制造标准化的牙骨质缺损。使用渐进性漂白技术，所有牙齿漂白6天，在第1天和第3天后更换漂白糊剂。将一水合过硼酸钠（MH）、三水合过硼酸钠（TRH）或四水合过硼酸钠（TH）与过氧化氢或水混合，随后置于唇侧CEJ下方1mm的冠内。牙齿分为六组：I. MH + 过氧化氢（30%）（n = 12）；II. TRH + 过氧化氢（30%）（n = 12）；III. TH + 过氧化氢（30%）（n = 12）；IV. TH + 水（n = 12）；V. TH + 水，凝胶（n = 12）；VI. 不使用漂白糊剂（n = 3）。在基线以及第1、3和6天，间接记录并计算从每个牙根周围介质中摄取的过氧化氢量，以ppm为单位。与对照组相比，几乎所有实验组的牙齿都显示出过氧化氢渗漏。I组和III组牙齿中过氧化氢的根管渗透明显高于IV组和V组（P≤0.001）。总之，过氧化氢渗漏量除其他因素外，取决于所用过硼酸钠的形式。（摘要截短为250字）
