Soldani Paula, Amaral Cristiane M, Rodrigues José A
Dental Research and Graduate Studies Division, Department of Restorative Dentistry, Guarulhos University, SP, Brazil.
Int J Periodontics Restorative Dent. 2010 Apr;30(2):203-11.
Bleaching systems and thickening agents lead to changes in the tooth enamel matrix as a result of an unspecific oxidation of the bleaching gel in the enamel. This reaction may result in a loss of mineral content and a decrease in microhardness. The aim of this study was to evaluate the effects of different bleaching systems and their thickening agents on the microhardness of human enamel in situ. Two dental slabs (3 x 3 x 2 mm) obtained from third molars were fixed on the buccal facial aspects of the maxillary first molars in a group of 45 volunteers. The volunteers were treated with 10% carbamide peroxide gel with carbopol as the thickening agent (group 1), 2% carbopol gel (group 2), 10% carbamide peroxide paste with poloxamer as the thickening agent (group 3), poloxamer (group 4), or 6.5% hydrogen peroxide strips for 21 days (group 5) (experimental treatment factor). The effects of the experimental treatment were evaluated by microhardness tests performed both before and after treatment (time factor). Data were submitted to split-plot analysis of variance and Tukey tests. Only time showed a statistically significant difference (P < .0001). All treatments reduced the enamel microhardness during treatment. Clinically, a reduction in microhardness can be expected after dental bleaching.
由于漂白凝胶在牙釉质中发生非特异性氧化，漂白系统和增稠剂会导致牙釉质基质发生变化。这种反应可能会导致矿物质含量的损失和显微硬度的降低。本研究的目的是评估不同漂白系统及其增稠剂对人牙釉质原位显微硬度的影响。从第三磨牙获取的两块牙片（3×3×2毫米）被固定在45名志愿者上颌第一磨牙的颊面。志愿者分别接受含卡波姆作为增稠剂的10%过氧化脲凝胶治疗（第1组）、2%卡波姆凝胶治疗（第2组）、含泊洛沙姆作为增稠剂的10%过氧化脲糊剂治疗（第3组）、泊洛沙姆治疗（第4组）或6.5%过氧化氢牙贴治疗21天（第5组）（实验治疗因素）。通过治疗前后进行的显微硬度测试评估实验治疗的效果（时间因素）。数据进行了裂区方差分析和Tukey检验。只有时间显示出统计学上的显著差异（P < .0001）。所有治疗在治疗期间均降低了牙釉质的显微硬度。临床上，牙齿漂白后可预期显微硬度会降低。
