10%过氧化脲延长漂白四环素染色牙的临床研究

目的：评价１０％过氧化脲６个月延长期的临床漂白效果。材料与方法：对３４名中、重度四环素染色牙的患者，制作含贮药池的扇形上颌个别托盘，采用Ｏｐａｌｅｓｅｎｃｅ１０％过氧化脲凝胶进行６个月的家庭漂白治疗，分别于漂白治疗前，治疗后第１周，第２周，第１月，第３月第６月，对照Ｖｉｔａｌｅｓｃｅｎｃｅ比色板，记录比较上前牙漂白颜色的改变并照相。结果：漂白治疗前，治疗后第１、３、６月的牙齿颜色存在显著性差异。３     

10%过氧化脲个体托盘漂白变色牙的临床观察

目的 评价10％过氧化脲对各种变色牙的临床漂白效果。方法 对23例变色牙患者的178颗牙制作含贮药池的马蹄形上下颌个体托盘，采用10％过氧化脲进行4周家庭漂白治疗。分别于漂白前后对照Vitalesence比色板，记录比较漂白牙色的改变。结果 178颗变色牙经漂白治疗，效果良好151颗，改善15颗，总有效率达93．3％。结论 10％过氧化脲是一种使用简便、安全、有效的牙齿漂白剂。     

临床评价不同活髓牙漂白术的效果

本文研究的目的是比较家庭漂白和诊室漂白的有效性和颜色改变后的稳定性,评估光源的使用是否会改变漂白效果。根据预先制定的标准,选择40名患者,并根据漂白治疗方案随机分为4组：①诊室漂白用10％过氧化脲,②诊室漂白用35％的过氧化氢（HP）,不带光源照射;③诊室漂白用35％过氧化氢,带石英卤钨光照射：④诊室漂白用35％的HP,带LED或激光照射。在漂白前,漂白后第1天,漂白后第3周,这3个时间点的牙齿颜色用VITA标准比色板进行评估。在完成漂白治疗后的第1个月和第6个月,再次用同一比色板评估牙齿的颜色,并对其进行统计分析。采用完全随机设计的非参数检验（KruskaI—WalliS检验）分析,得出的结果显示各组间在任何时间点上的差异无统计学意义（P〉0.01）。并且得出,所有组都没有出现颜色反弹现象;以上4种漂白方案都产生了有效的漂白效果;牙齿漂白不一定需要光源照射。     

过氧化氢酶对外漂白后树脂充填体边缘微渗漏的影响

目的： 观察过氧化氢酶对10%过氧化脲外漂白后复合树脂充填体边缘微渗漏的影响。方法： 选取牙体健康完整的人离体前磨牙40颗,随机分为4组,第1组不漂白直接进行树脂充填,第2组外漂白后立即树脂充填,第3组外漂白后将牙在人工唾液中浸泡3周再进行树脂充填,第4组外漂白后先用过氧化氢酶处理窝洞再进行树脂充填。然后将4组样本进行2000个周期的冷热循环,应用2%亚甲基蓝染色24 h,体视显微镜下观察剖面树脂充填体的微渗漏程度,采用SPSS17.0软件包对数据进行统计学分析。结果： 第1组微渗漏值最低,第2组微渗漏值最高,第3组微渗漏值显著高于第1组但与第2组相比无显著差异（P>0.05）;第4组微渗漏值较第2组显著下降（P<0.05）。结论： 10%过氧化脲外漂白致树脂充填体边缘微渗漏明显增加,树脂充填前应用过氧化氢酶处理窝洞,可有效减少微渗漏,延迟充填不能有效改善微渗漏。     

病例报告:夜间漂白和内漂白联合治疗四环素牙

四环素牙是牙齿美容学中颇受关注的对象,但目前临床治疗现状尚不令人满意。本文报告一例成功应用夜间漂白(nightguard bleaching)及内漂白联合治疗四环素牙的病例。一、检查及诊断:患者,女,36岁,中国人,前牙中重度四环素牙,左上中切牙近中切角缺损(图1)。病史记录儿童期曾服用四环素。患者主诉牙龈出血,要求美白牙齿改善面容。拟定选用10%过氧化脲行家庭漂白,树脂修复左上中切牙切角缺损。建议首先行牙周治疗。图1治疗前患者前牙呈中重度四环素牙二、漂白过程1.家庭漂白:牙周治疗后,选用ADA批准的10%过氧化脲漂白剂(Ultradent Products,I…     

10%过氧化脲漂白内源性着色活髓牙的疗效分析

目的观察10%过氧化脲漂白对不同原因内源性着色活髓牙的漂白效果。方法对36例患者568颗内源性着色活髓牙进行药物漂白治疗,其中增龄性变色牙72颗,四环素牙287颗,氟斑牙209颗。对照Vita比色板,观察记录其治疗前、后的色阶变化并评价其临床疗效。结果经不同时间的漂白治疗后,各组着色牙的色阶值显著降低(P<0.05)。不同原因着色牙的治疗效果不同,但其总体有效率差异无显著性(P>0.05)。结论10%过氧化脲漂白对不同原因导致的内源性着色活髓牙均有较好的漂白作用。     

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目的评价不同漂白方法对氟斑牙漂白的临床效果。方法轻中度氟斑牙患者30例随机分为3组,每组10例60颗牙。分别采用联合漂白、激光漂白、家庭漂白3种方法进行上前牙区漂白,在漂白前、漂白后即刻、漂白后1个月、漂白后1年记录其L＊a＊b＊值,比较3组漂白效果及颜色回复情况。应用统计学分析软件CS10.34对数据进行t’检验。结果 3组漂白后的L＊a＊b＊值与漂白前比较差异均有统计学意义（均P〈0.05）;漂白后1个月,联合组与激光组颜色有所回复（P〈0.05）;漂白后1年,联合组、激光组颜色与漂白后即刻相比有所回复（P〈0.05）,与漂白后1个月相比颜色回复差异无统计学意义（P〉0.05）;家庭组颜色回复差异无统计学意义,但1个月到1年期间颜色变化小于治疗后即刻到1个月的变化（P〈0.05）。结论 3种漂白方案治疗1个疗程都得到相似的美白效果,但短期内也出现漂白牙的颜色回复,家庭漂白颜色相对稳定,诊室漂白收效快,3种治疗方案各有其适应人群。     

诊室加热恒温漂白对不同牙位自然牙漂白效果的临床评价

目的评价不同牙位的自然牙在诊室加热恒温漂白治疗后颜色改善的效果。方法按照纳入标准挑选6名受试者,采用隔天漂白操作3次,每次操作15 min的方式进行诊室加热恒温漂白,测量受试者右上中切牙、右上侧切牙和右上尖牙漂白操作前,第1、2、3次漂白操作后,以及术后1周和1月的L*、a*、b*颜色参数值,计算色差值和白度值。结果不同牙位漂白后的色差值及白度值差值不存在统计学差异(P>0.05),不同漂白阶段及术后1周、1月的色差值及白度值差值之间也不存在统计学差异(P>0.05)。结论不同牙位的自然牙在诊室加热恒温漂白治疗后颜色改善的效果无明显差异。     

Beyond冷光美白染色牙的临床疗效评价

目的：评价Beyond冷光美白对天然染色牙或四环素染色牙的美白效果。方法：用Beyond冷光美白仪和美白剂对39例染色牙（19例天然染色牙,20例四环素染色牙）进行1个疗程的冷光美白治疗,用Vita比色板评价牙齿颜色变化程度。结果：天然染色牙组治疗前平均颜色等级为10.71±2.38,治疗后为6.50±2.76,四环素染色牙组治疗前平均颜色等级为15.62±4.38,治疗后为11.30±4.51,天然染色牙组及四环素染色牙组治疗前后的牙齿颜色均存在显著性差异（p〈0.01）。结论：Beyond冷光美白对天然染色牙及四环素染色牙可以取得较好的美白效果。     

10%抗坏血酸钠对外漂白后复合树脂充填体微渗漏的影响

目的观察10%抗坏血酸钠与含表面活化剂(Tween,0.2%)的10%抗坏血酸钠对经10%过氧化脲外漂白后复合树脂充填体微渗漏的影响。方法选取牙体完整健康的人离体前磨牙50颗,随机分为5组,第1组不漂白直接树脂充填,第2组用10%过氧化脲漂白后立即树脂充填,第3组漂白后将牙齿浸泡在人工唾液中3周再进行树脂充填,第4组漂白后先用10%抗坏血酸钠处理窝洞后再充填树脂,第5组漂白后先用含0.2%Tween的10%抗坏血酸钠处理窝洞后再进行树脂充填。然后,将5组样本进行2000个周期的冷热循环,2%亚甲基蓝染色24h,体视显微镜下观察剖面充填体的微渗漏情况。结果第1组微渗漏值最低,第2组微渗漏值最高,第3、4组微渗漏值显著高于第1组但与第2组无显著性差异(P>0.05);第5组渗漏值较第2组及第4组显著下降(P<0.05)。结论 10%过氧化脲外漂白致复合树脂充填体边缘微渗漏明显增加,含0.2%Tween的10%抗坏血酸钠处理窝洞可以有效减少该微渗漏的增加,延迟充填和单纯使用抗坏血酸钠均不能有效减少微渗漏。     

Efficacy of a novel at-home bleaching technique with carbamide peroxides modified by CPP-ACP and its effect on the microhardness of bleached enamel

This study was designed to evaluate in vitro the efficacy of a novel at-home bleaching technique using 10% or 16% carbamide peroxide modified by casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and its influence on the microhardness of bleached enamel. A total of 40 bovine incisors were divided into four groups (n=10) according to the bleaching agent used: 10% carbamide peroxide only; a blend of 10% carbamide peroxide and a CPP-ACP paste; 16% carbamide peroxide only; and a blend of 16% carbamide peroxide and a CPP-ACP paste. During the 14-day bleaching regimen, the samples were stored in artificial saliva. The Vickers microhardness and color of the teeth were assessed at baseline (T0) and immediately after the bleaching regimen (T14) using a microhardness tester and a spectrophotometer, respectively. The degree of color change was determined by the Commission Internationale de l'Eclariage (CIE) L*a*b* system (ΔE, ΔL*, Δa*, and Δb*) and Vita shade guide parameters. The data were analyzed by analysis of variance and the Tukey test (p<0.05). The teeth that were bleached with a blend of peroxide (10% or 16%) and the CPP-ACP paste presented increased microhardness values at T14 compared with T0, whereas the samples that were bleached with peroxide only did not show any differences in their microhardness values. All of the bleaching agents were effective at whitening the teeth and did not show a statistically significant difference using the CIEL*a*b* system (ΔE, ΔL*, Δa*, and Δb*) or the Vita shade guide parameters. The use of a CPP-ACP paste with carbamide peroxide bleaching agents increased the bleached enamel's microhardness and did not have an influence on whitening efficacy.     

Colorimetric Assessment of Laser and Home Bleaching Techniques

Abstract: Purpose: This study recorded in vitro color change of three tooth bleaching techniques that included laser-activated hydrogen peroxide and two concentrations of carbamide peroxide.
Materials and Methods: Forty extracted human central incisors were exposed to argon laser-activated 35% H₂O₂, 10% carbamide peroxide, or 20% carbamide peroxide. A fourth group (control) did not receive any bleach treatment (n = 10/group). Commission International de ľEclariage (CIE) L*a*b* coordinates were recorded prior to bleaching (baseline), at 1 week, and at 2 weeks. The color difference (ΔE*ab) between baseline and subsequent measurents was calculated.
Results: The control group did not demonstrate significant color difference over time ( p > .05). The laser group was not statistically different from the control group ( p > .01). The color difference of the 10% and 20% carbamide peroxide groups was statistically different from the control group ( p < .01).     

Intracoronal bleaching of discolored non-vital teeth

This clinical study compared the effectiveness of bleaching non-vital teeth with an open pulp chamber during bleaching using 10% carbamide peroxide compared to the modified walking bleach technique and extracoronal bleaching. Sixty discolored, non-vital teeth were treated. They were divided into three groups. Each group was treated with one of the bleaching materials and methods: extracoronally using 10% carbamide peroxide for two weeks as negative control (Group A), intracoronally using sodium perborate mixed with 3% hydrogen peroxide (modified walking bleach technique) (Rotstein, Mor & Friedman, 1993) for four weeks (Group B) and intracoronally and extracoronally using 10% carbamide peroxide for two weeks (Group C) (Liebenberg, 1997). Tooth color was measured at baseline, (BL), immediately post-bleaching (IP) and six months post-bleaching (SP) with a colorimeter (Castor, Sigma, Germany) using a tooth-positioning jig. The color was determined according to the CIELAB system, which records lightness as L* and chromaticity coordinates as a* and b*. The difference in L* and b* among the three groups was significant between BL and IP examination. The post-bleaching, whitening effect in Group C was significantly better, but after six months, in Group C, it was as effective as in Group B.     

Nd—YAG激光漂白四环素牙效果观察

目的：评价Nd-YAG激光漂白四环素牙的有效性及持续性。方法：采用Nd-YAG激光及漂白糊剂实施诊室漂白及2周家庭漂白。利用PR－560测色计CIEL^*a^*b^*表色系对漂白前术后1d，2周，3月及6月的牙齿分别测色，分析牙色的变化。结果：漂白牙齿的平均测色结果表示，术后复查各阶段L^*均高于术前，与术前比较均有显著性差异（P＜0．01）；b^*均低于术前，除6月，术后各阶段与术前比较均有显著性差异（P＜0．05）；a^*各阶段与术前比较均无显著性差异。色差△E值呈逐渐下降趋势。结论：Nd-YAG激光漂白四环素牙即刻效果卓越，短期效果明显。     

Scanning electron microscopy study of dental enamel surface exposed to 35% hydrogen peroxide: alone,with saliva,and with 10% carbamide peroxide

Several vital bleaching systems have been introduced in response to the demand in esthetic dentistry. The active agents are commonly hydrogen peroxide or carbamide peroxide used in at-home or in-office techniques. Although generally positive results have been reported concerning the whitening ability of these agents, concerns still remain as to their effects on dental tissues. The purpose of this investigation was to evaluate the effect of these bleaching agents on the enamel surface morphology. Twelve extracted teeth were used according to three experimental protocols. In experimental protocol 1, specimens were treated with 35% hydrogen peroxide. In experimental protocol 2, after treatment with 35% hydrogen peroxide the specimens were immersed in natural saliva for 1 week. In experimental protocol 3, 35% hydrogen peroxide was applied once and 10% carbamide peroxide was applied for 1 week (12 h of 10% carbamide peroxide alternating with 12 h saliva). Scanning electron microscopy evaluation revealed that regional variation in tooth morphology surface sometimes exceeded the effects of the peroxide used according to experimental protocols. Thirty-five percent hydrogen peroxide had a tendency to promote an increase in density of pits. Precipitates were observed on specimen surfaces immersed in natural saliva according to protocol 2. A smooth and shiny surface was observed in specimens treated according to protocol 3. The potential relationship between surface alterations and differences in enamel permeability is currently under investigation. CLINICAL SIGNIFICANCE The differences in various articles written on the subject cannot be reconciled because of the lac of standardization of baseline data regarding factors such as location on the tooth, type of tooth eruption or noneruption, and age in the oral cavity. This article demonstrates that, despite changes observed in the enamel surface after bleaching, normal variation in tooth morphology may exceed the effects of 35% hydrogen peroxide and 10% carbamide peroxide on the teeth. Hence, considering the morphologic features of the tooth surface, bleaching, as described in thi study, can be considered safe for enamel.     

Clinical study of tooth shade lightening from dentist-supervised, patient-applied treatment with two 10% carbamide peroxide gels

PURPOSE: Prescribed, patient-applied tooth lightening agents, or nightguard vital bleaching, typically utilizes a 10% carbamide peroxide agent applied during nocturnal hours. The purpose of this randomized double-blind study was to compare the amount of tooth color change in two groups of subjects using dentist-supervised, patient-applied 10% carbamide peroxide gel. MATERIALS AND METHODS: One group used Opalescence (Ultradent Products Inc., South Jordan, Utah) and the other NiteWhite Excel (Discus Dental, Inc., Los Angeles, California). Evaluation of tooth color for the six maxillary anterior teeth was done using a Vita shade guide at baseline, 1, 2, and 4 weeks. Subjects were instructed to apply the gel nocturnally using a custom-made soft tray 8 hours per day for 2 weeks. The 16 tabs of the shade guide were ranked according to value from darkest to lightest. The number (1-16) that correlated to the shade tab selected as the match for each tooth was the outcome variable. A Kruskal-Wallis one way analysis of variance on ranks was used. RESULTS: The test revealed no statistically significant difference between Opalescence and NiteWhite Excel for lightening the teeth (p = .807). The color change was still significant after 2 weeks without further bleaching activity. The baseline evaluation of the maxillary incisors and canines for all subjects, regardless of group, demonstrated a significant shade difference, with the canines being darker. This difference was not seen after 2 weeks of active bleaching or at the 4-week evaluation. CLINICAL SIGNIFICANCE: In this study comparing bleaching products, patients using Opalescence and NiteWhite Excel experienced a significant change in the color of their teeth relative to baseline values after 2 weeks of active treatment.     

Effect of different bleaching techniques on enamel surface microhardness.

Conservative techniques for treatment of discolored human enamel include in-office bleaching with heat-activated 35% hydrogen peroxide, Nightguard vital bleaching with 10% carbamide peroxide, and enamel microabrasion with 18% hydrochloric acid. OBJECTIVES: In this study, these bleaching techniques were performed on 30 extracted teeth to evaluate their effects on microhardness of enamel surfaces. METHODS: The enamel surface microhardness measurements were performed 0, 24, 48, and 72 hours and 1 week after treatment. Paired t tests were performed in the statistical analyses. RESULTS: No changes were found on specimens treated with carbamide peroxide. There was a significant decrease in the surface microhardness of enamel after 0 and 24 hours when the specimens were treated with 18% hydrochloric acid (softening 85.7 and rehardening 99.4) or with 35% hydrogen peroxide (softening 85.7). However, after 72 hours, significant rehardening was observed in these groups (P <.001). CONCLUSION: According to the results, except Nightguard vital bleaching, all other techniques softened the enamel surface.     

Two-year clinical evaluation of tooth whitening using an at-home bleaching system.

PURPOSE: The purpose of this study was to evaluate the 2-year effectiveness of a carbamide peroxide at-home bleaching gel used to provide tooth lightening treatment. MATERIAL AND METHODS: Twenty-nine patients participated in the original study, during which they treated their maxillary teeth with a 10% carbamide peroxide gel nightly for 2 weeks. Shades were determined before and after treatment by comparison with a Vita shade guide. Twenty-four patients (a recall rate of 83%) were recalled for evaluation 2 years after the initial bleaching treatment. The shade of the maxillary incisors was evaluated and compared with shades before, immediately after, and at 6 months and 2 years after initial treatment. Data were analyzed using a repeated-measures analysis of variance. RESULTS: At 2 years after bleaching with a 10% carbamide peroxide gel, the median shade was D2, a six-increment difference from the baseline median of D3. Twenty of 24 patients (83.3%) had a shade change of two or more units, which is the threshold value for bleaching efficacy using American Dental Association guidelines. The lightening result remained statistically significant (p < .0001) at 2 years. CLINICAL SIGNIFICANCE: Although some reversal of the lightening effect occurs over time following the original bleaching treatment, loss of the lighter color appears to be gradual for most patients. Although the longevity of the lightening effect remains to be determined, this clinical trial indicates that the majority of patients have a satisfactory result 2 years after treatment.     

Comparison of 10% carbamide peroxide and sodium perborate for intracoronal bleaching

The purpose of this study was to compare 10% carbamide peroxide to the combination of sodium perborate and water as intracoronal bleaching agents. Forty-four extracted teeth were discolored in vitro. Bleaching agents were placed intracoronally to the level of the cemento-enamel junction for 12 days; solutions were replaced after four and eight days. Standardized slides were used to rank color changes; a colorimeter was used to quantify color change. After 12 days, 65% of the discolored teeth in the 10% carbamide peroxide group and 67% of the discolored teeth in the sodium perborate group had lightened to their original shade or lighter. While there was no statistical difference between the two treatments, sodium perborate was easier to use.