三种牙齿漂白方案的短期效果比较研究

目的:体外评价三种漂白方案对人牙齿漂白的短期效果.方法:36颗刚拔除的人牙,沿唇(颊)舌方向中央剖开去髓后,随机分成三组,联合漂白组(A):38%HP45min/d×1+15%CP 8h/d×4;诊室漂白组(O):38%HP45min/2×2,家庭漂白组(H):15%CP 8h/d×14.分别于漂白前,漂白后即刻(0天),4天、7天、14天、21天用Crystaleye分光光度计电脑比色仪拍摄牙齿唇(颊)面照片,分析测量牙齿体部靠近中线区的漂白前后△E值.结果:疗程结束时,3组漂白效果无统计学差异(P>0.05);3组在漂白结束后4天时与漂白结束△E有统计学差异,但H组在7天后△E无统计学差异,而A、O组2周、3周时仍有统计学差异.结论:三种漂白方案短期内都有颜色回复,但回复量和持续时间不同.     

漂白后牙齿颜色稳定性的初步研究

目的:体外评价牙漂白后28 d内的颜色变化.方法:采用标准红茶溶液建立外着色牙模型.48个牛牙样本外着色后(Vita 3.5～4)随机分为A,B,C,D 4组,其中前3组进行350 mL/L过氧化氢漂白,漂白后分别浸泡入天然唾液,人工唾液,去离子水中,D组为阴性对照.采用PR-650光谱扫描色度仪测量,并以CIE-LAB颜色系统记录各组漂白前,漂白后即刻、1、3、5、7、14、21、28 d的牙齿颜色L,a,b值,并对各观测点的△L,△a,△b,△E进行分析.结果:同D组相比,各漂白组均显示明显的牙齿颜色变浅(P<0.05);同漂白后即刻相比,各组内的△L,△b,△E在漂白后28d内均有明显变化,漂白后1～3 d最为明显,7 d后逐渐达到稳定(P<0.05);漂白组组间比较,在28 d时A和C组AE值有显著差别(P<0.05).结论:在体外条件下,牙漂白后颜色可发生回复,1周达到稳定;颜色回复可能与漂白后牙体组织矿物质结构的改变有关.     

过氧化氢凝胶对离体牙内部组织颜色的影响

目的:通过观察牙体组织在漂白过程中的颜色变化,了解牙齿漂白的作用过程并指导临床使用。方法:将处理过的12颗离体牙随机分为2组,分别使用75g/L和350g/L的过氧化氢凝胶漂白剂进行处理,每组6个样本中1个作为空白对照。350g/L组在放置漂白剂之前、之后10min、30min,75g/L组则在放置漂白剂之前、之后1.5×N(N=0、1、2、3、4、5、6、7)h分别在照明、摄影参数固定的情况下摄取数码照片并使用Photoshop7.0软件进行分析。结果:试验组通过肉眼观察都出现了逐渐变白的趋势,图像分析表明牙剖面与表面整个区域颜色变化均非常明显,在剖面上未直接接触漂白剂的牙根颜色变化甚至超过牙冠。350g/L组实验对象还观察到牙齿出现了脱矿的倾向。对L*a*b*值进行统计,结果为L*即明度上升,b*值下降,a*值基本不变。结论:漂白有效成分对牙体硬组织全层均产生作用,而且渗透发生的时间很短。350g/L的过氧化氢漂白剂会造成硬组织的严重脱矿,75g/L浓度更加安全可靠。     

漂白剂的pH值对牙齿表面形貌和颜色的影响

目的:研究漂白剂的pH值对牙齿颜色和表面特性的影响,为临床应用提供实验依据。方法:50颗前磨牙包埋在环氧树脂中,近远中方向纵向剖开,由于部分牙齿在切割过程中损坏,获得颊部薄片和牙主体部分,得到35片颊侧切片。将试样随机分为5个组:DW组(阴性对照组)使用蒸馏水处理(pH=7.0);HCl组(阳性对照组)使用HCl处理(pH=3.0);HP3组、HP7组、HP8组分别使用pH值为3、7、8的30%过氧化氢溶液进行处理。用分光光谱仪测量颜色变化。扫描电镜观察釉质表面形貌改变。结果:漂白剂的pH值对漂白后的牙齿颜色有显著影响(P<0.0001)。根据Tukey Post-hoc多重检验,颜色变化顺序为:HP7>HP8>HP3>HCl>DW。HP7、HP8和DW三组的釉质表面均无明显形态学改变。HCI和HP3组釉质表面均呈明显的侵蚀外观。结论:不管是碱性还是中性漂白剂,对牙釉质表面特性均无明显影响。酸性漂白剂对牙釉质表面有较明显的侵蚀性,同时具有轻微的美白效果。     

氟化物预处理减轻漂白治疗术中牙齿敏感的扫描电镜观察

目的观察氟化物对漂白治疗中牙体硬组织微结构的影响，探讨氟化物用于减轻漂白治疗中牙齿敏感的可行性及其作用机制。方法选取临床因正畸治疗需拔除4颗健康第一前磨牙的患者共12名，按处理方法不同随机分为3组：加氟化钠漂白组、漂白组和空白组。在不同处理后分别制备釉质、牙本质纵剖面和横剖面电镜观察标本，以扫描电镜观察其超微结构改变情况。结果电镜显示漂白组釉质表面出现溶融、脱矿现象；牙本质纵剖面可见管周牙本质轻微脱矿，管间牙本质胶原纤维网架塌陷；横剖面见牙本质小管口因脱矿而呈现不规则，小管径增大。加氟化钠漂白组釉质及牙本质的脱矿程度均减轻，牙本质小管口小于漂白组。结论局部应用氟化钠可减轻釉质表层及牙本质脱矿，降低牙体硬组织通透性，从而缓解漂白过程中所产生的牙齿敏感症状。     

光学相干成像无创检测不同漂白方法对釉质白斑治疗效果的实验研究

目的 探讨采用光学相干成像技术(OCT)检测不同漂白方法对釉质白斑的治疗效果,评价其用于釉质白斑治疗效果监测的可行性。方法 选取因正畸拔除的完整离体前磨牙48颗,在牙冠颊面正中切取4 mm×4 mm×2 mm釉质块。在其表面(除颊侧面外)涂布抗酸指甲油后,置于脱矿溶液中浸泡18 d,建立釉质白斑体外脱矿模型。将样本随机分为4组(n=12),A组为对照组仅脱矿处理;B组为40%过氧化氢漂白处理;C组为Icon渗透树脂处理;D组为40%过氧化氢漂白联合Icon渗透树脂处理。每组随机抽取8个样本,应用OCT扫描釉质块颊侧面,观察各组釉质表层成像变化并测量表层光强改变;将釉质块用环氧树脂包埋固定(仅暴露颊侧面),显微硬度仪测量并记录各组硬度值变化。各组剩余4个样本纵向切开,扫描电镜观察各组样本超微结构变化。结果 OCT显示,各组釉质表层光散射特性均发生改变,可见高亮层形成,但C、D组的高亮层厚度显著低于A、B组(P<0.05)。各组样本显微硬度值分别是(214.99±31.70)、(250.66±33.64)、(312.42±18.01)、(286.53±26.65)kg/mm^...     

不同过氧化物对牙釉质结构和硬度的影响

目的:探究30%过氧化氢(hydrogen peroxide,HP)、22%过氧化脲(carbamide peroxide,CP)、3%过硼酸钠(sodium perborate,SP)对离体牙漂白后牙齿釉质表面结构和硬度的差异。方法:筛选正常人离体牙标本并随机分为A、B、C、D 4组,分别用生理盐水、30%过氧化氢、22%过氧化脲、3%过硼酸钠对4组牙齿进行漂白处理,最后对离体牙进行电镜扫描(×2000)和维氏硬度测定并进行统计分析。结果:实验组与对照组相比,扫描电镜显示: 30%过氧化氢和3%过硼酸钠组,其釉质表面呈散在的孔状,蜂窝状破坏,说明牙齿出现了不同程度的脱矿、溶解;22%过氧化脲组牙齿釉质表面结构基本完整,无明显脱矿和溶解现象;硬度测定结果显示:组间两两比较存在差异性(P＜0.05),漂白后4个组牙齿硬度大小是:对照组＞22%过氧化脲组＞3%过硼酸钠＞30%过氧化氢。结论:3种过氧化物漂白试剂中22%过氧化脲对牙釉质结构和硬度的影响最小。     

Croll法釉质微打磨和漂白对氟斑牙的疗效

目的探讨Croll釉质微打磨和漂白联合应用治疗氟斑牙的疗效。方法将患者有氟斑牙着色的上颌前牙按中线分为两组,随机采用Croll法釉质做打磨或Croll法釉质微打磨后漂白4周,通过比色板记录牙齿的颜色,并通过表格比较这两种方法对牙齿敏感和牙龈刺激程度的影响。结果 Croll釉质微打磨后漂白4周的牙齿颜色比单独Croll法釉质微打磨的牙齿颜色更白(P<0.01),这两种方法牙齿敏感和牙龈刺激程度差异无显著性(P>0.05)。结论 Croll法釉质微打磨与漂白联合应用治疗氟斑牙效果更好。     

过氧化脲漂白剂对釉质显微硬度影响的实验研究

目的:评价不同载体和浓度的过氧化脲(carbam ide peroxide,CP)漂白剂对釉质表面显微硬度的影响。方法:在18个离体前磨牙的颊、舌面各制备2 mm×2 mm的平面,随机分为6组。分别用卡波姆(Car-bopol)、聚乙烯吡咯烷酮(PVP)或泊洛沙姆(poloxam er)为增稠载体的含11%、21%CP的漂白剂,在37℃100%湿度条件下每天漂白6~8 h,持续2周。漂白前、后测量釉质表面的显微硬度。21%CP治疗组在漂白治疗结束后继续浸入人工唾液2周,再次测量显微硬度。结果:11%CP漂白2周后,釉质的显微硬度与漂白前相比没有显著差异(P>0.05);21%CP漂白2周后,釉质的显微硬度明显低于漂白前(P<0.01),继续浸入人工唾液2周,显微硬度明显高于漂白后(P<0.05),但与漂白前相比仍有显著差异(P<0.05)。在相同CP浓度下,不同增稠载体组间的显微硬度没有显著差异(P>0.05)。结论:11%CP漂白剂对釉质的显微硬度没有影响,21%CP漂白剂可明显降低釉质的显微硬度,人工唾液可在一定程度上增加釉质的再矿化能力,不同的增稠载体对釉质的显微硬度没有明显影响。     

漂白剂对玻璃离子水门汀类材料充填Ⅴ类洞边缘微渗漏的影响

目的评估漂白凝胶和洁白牙贴对3种不同的玻璃离子水门汀类材料边缘微渗漏的影响。方法在45颗离体健康前磨牙的颊舌侧制备Ⅴ类洞,随机分为A、B、C组,分别使用加强型玻璃离子水门汀KetacTM Molar Easymix、复合体F2000、复合体Dyract AP充填,每个大组再分为3个亚组,第1组和第2组分别使用质量分数14％过氧化氢（HP）洁白牙贴和10％过氧化脲（CP）凝胶进行漂白,第3组为对照组。所有样本置入37 ℃蒸馏水中保存7 d后冷热循环500次,然后进行漂白。漂白21 d后置于碱性品红溶液中染色24 h,沿牙体长轴通过充填体中央颊舌向剖开牙齿,体视显微镜下观察并测量染料渗入窝洞壁的深度。结果2种漂白方式对充填体边缘微渗漏的影响没有明显差异（P>0.05）;与对照组相比,2种漂白方式对B、C组的微渗漏均没有产生明显影响（P>0.05）,但均可使A组的微渗漏增加（P<0.05）。结论10％CP凝胶和14％HP洁白牙贴对充填体边缘微渗漏的影响无明显差异;漂白不会影响复合体的微渗漏,但会增加加强型玻璃离子水门汀的微渗漏。     

Effectiveness of different carbamide peroxide concentrations used for tooth bleaching: an in vitro study

Objectives

This in vitro study evaluated the effectiveness of three carbamide peroxide concentrations used for tooth bleaching treatments.

Material and Methods

Sixty bovine dental slabs (6x6x3 mm) were obtained, sequentially polished, submitted to artificial staining (baseline) and randomized into four groups (n=15), according to the bleaching agent concentration: distilled water (control), 10% (CP10), 16% (CP16) or 37% (CP37) carbamide peroxide. CP10 and CP16 were covered with 0.2 mL of the respective bleaching gels, which were applied on enamel surface for 4 h/day during two weeks. Samples of CP37 were covered with 0.2 mL of the bleaching gel for 20 min. The gel was light activated by two 40-s applications spaced by 10-min intervals. The gel was renewed and applied 3 times per clinical session. This cycle was repeated at 3 sessions with 5 days of interval between them. Tooth shade evaluations were done with a digital spectrophotometer at T0 (baseline), T1 (after 1-week of treatment) and T2 (1-week post-bleaching). Tooth shade means were statistically analyzed by Kruskal-Wallis and Friedman''s tests and color parameters were analyzed by two-way ANOVA and Tukey''s test (p<0.05).

Results

At T1 and T2 evaluations, tooth shade was significantly lighter than at baseline for all treatment groups, considering the color parameters ΔL*, Δa*, Δb*, ΔE* (p<0.001) or tooth shade means (p<0.001). CP37 group showed lower shade mean change than CP10 and CP16 at T1 (p<0.01), but this difference was not statistically significant at T2 (p>0.05).

Conclusions

One week after the end of the treatment, all carbamide peroxide concentrations tested produced similar tooth color improvement.     

Occurrence of sensitivity during at-home and in-office tooth bleaching therapies with or without use of light sources

The aim of this study was to evaluate the effect of tooth bleaching with 10% carbamide peroxide (CP) or 35% hydrogen peroxide (HP), with or without quartz-tungsten-halogen light or hybrid source LED/infrared laser exposition on the occurrence duration, intensity and location of tooth sensitivity Forty patients were selected and randomly divided into four groups: GI--home bleaching with CP for 4 hours a day, over the course of 3 weeks; GII--three sessions of HP with three 10-minute applications at each session and no light source; GIII--the same procedure as GII with quartz-tungsten-halogen light irradiation; GIV--the same procedure as GII with LED/laser light irradiation. The evaluation included an appointment with each patient before and after each HP bleaching session or each weekly CP bleaching and 7, 30 and 180 days after the end of treatment. The Kruskal-Wallis test revealed that the duration and intensity of post-treatment sensitivity were significantly higher for HP than for CP (p< 0.05), and symptoms were located predominantly in anterior teeth. All bleaching methods generated sensitivity, which was more frequent in anterior teeth. However, treatment with CP generated lower sensitivity than treatment with HP independently of the light sources.     

High-efficiency tooth bleaching using non-thermal atmospheric pressure plasma with low concentration of hydrogen peroxide

Light-activated tooth bleaching with a high hydrogen peroxide (HP; H₂O₂) concentration has risks and the actual role of the light source is doubtful. The use of conventional light might result in an increase in the temperature and cause thermal damage to the health of the tooth tissue.

Objective:

This study investigated the efficacy of tooth bleaching using non-thermal atmospheric pressure plasma (NAPP) with 15% carbamide peroxide (CP; CH₆N₂O₃) including 5.4% HP, as compared with conventional light sources.

Material and Methods:

Forty human teeth were randomly divided into four groups: Group I (CP+NAPP), Group II (CP+plasma arc lamp; PAC), Group III (CP+diode laser), and Group IV (CP alone). Color changes (ΔE ) of the tooth and tooth surface temperatures were measured. Data were evaluated by one-way analysis of variance (ANOVA) and post-hoc Tukey''s tests.

Results:

Group I showed the highest bleaching efficacy, with a ΔE value of 1.92-, 2.61 and 2.97-fold greater than those of Groups II, III and IV, respectively (P<0.05). The tooth surface temperature was maintained around 37ºC in Group I, but it reached 43ºC in Groups II and III.

Conclusions:

The NAPP has a greater capability for effective tooth bleaching than conventional light sources with a low concentration of HP without causing thermal damage. Tooth bleaching using NAPP can become a major technique for in-office bleaching in the near future.     

漂白剂对牙颈部硬组织影响的扫描电镜研究

目的：观察漂白剂直接作用于牙颈部后牙的结构变化。方法：选用几种不同的漂白剂，直接作用于牙颈部，应用扫描电镜观察漂白剂引起的牙本质、釉质、牙骨质的结构变化。结果：牙颈部的牙骨质、牙本质均有结构上改变，釉质变化不明显。结论：提出预防牙颈部外吸收的措施，使临床上能安全、有效地应用漂白技术     

Beyond冷光美白与过氧化脲漂白四环素牙的疗效比较

目的评价Beyond冷光美白法漂白四环素牙的疗效及安全性。方法用Beyond冷光美白仪及配套的冷光美白剂,对试验组50例患者712颗四环素牙进行脱色。对照组50例患者717颗四环素牙用奥伦增白剂漂白作对照。用VITA比色板作脱色前、后比色,比较脱色效果,观察牙齿敏感情况。结果试验组脱色总显效率为86.5%,对照组为58.7%,两者差异有显著性(P<0.05)。试验组有6例(12.0%)患者出现牙齿轻度酸痛不适感,对照组有11例(22.0%)患者出现不同程度的牙齿酸痛感,两者差异有显著性(P<0.05)。结论Beyond冷光美白法脱色四环素牙有效、安全、快速。     

分光光度比色仪对牙齿漂白效果的分析

目的 采用分光光度比色仪分析牙齿漂白后不同部位颜色CIE L*、a*、b*值的变化。方法 选择67个健康完整的上颌中切牙,颜色大于A3（Vita经典比色板）。分光光度比色仪比色,记录颈部、体部、切端牙色。进行诊室漂白治疗（35%H2O2协同冷光漂白仪）后再次记录各部位牙色,计算ΔE、ΔL*、Δa*、Δb*和治疗有效率。对数据进行方差分析、配对t检验和Pearson相关分析。结果 治疗有效率分别为：颈部86.6%,体部86.6%,切端85.1%。ΔE均值：颈部5.09,体部4.44,切端4.40。漂白后L*值升高,a*和b*值降低,均有统计学差异（P<0.01）。颈部和体部基线b*值与ΔE成正相关。结论 35%H2O2协同冷光漂白仪照射有较好的牙齿漂白效果,顺序为颈部>体部>切端。颈部黄色降低幅度最大,切端明度增加最多。基线b*值越高,色差越大。     

氟化物与过氧化氢类漂白剂联用对大鼠牙髓影响的组织病理学观察

目的从组织学水平观察高浓度漂白剂与氟化物联用对大鼠牙髓的影响。方法将60只大鼠按处理方法不同随机分为加NaF漂白组、漂白组和空白组,其中NaF漂白组和漂白组分别按5、10和15 min 3个不同的治疗时间进行漂白处理,然后对即刻、3 d后和7 d后的牙髓情况进行组织病理学观察。结果全部受试牙中仅有1/3出现轻度牙髓反应,没有出现中度或重度牙髓反应,并且这些轻微牙髓反应在治疗结束后即可出现,一般在2周内恢复正常,NaF漂白组和漂白组之间无统计学差异。结论动物实验结果显示高浓度过氧化氢类牙齿漂白治疗可引发轻微、局限性的牙髓反应,漂白治疗术前氟化物的应用对牙髓反应等级无明显影响。     

An in vitro comparison of the bleaching efficacy of 35% carbamide peroxide with established intracoronal bleaching agents

AIM: To evaluate the bleaching efficacy of 35% carbamide peroxide, 35% hydrogen peroxide and sodium perborate for intracoronal bleaching of root filled discoloured teeth. METHODOLOGY: Extracted premolars were artificially stained using whole blood then root canal treatment was performed. After obturation, a 2 mm intermediate base was placed 1 mm below the buccal amelo-cemental junction. Intracoronal bleaching was performed in 11 teeth per group, using either 35% carbamide peroxide gel (group CP), 35% hydrogen peroxide gel (group HP) or sodium perborate mixed with distilled water (group SP). The bleaching agents were replaced after 7 days. The shade of the teeth was evaluated at day 0, 7 and 14. The results were analysed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U-test. RESULTS: At the end of 7 days, both groups CP and HP lightened by 8 +/- 3 Vita tab positions, respectively, whereas group SP lightened by 5 +/- 3 tab positions (P < 0.05). At the end of the second bleaching period at day 14, group CP and HP lightened by a further 2 +/- 2 and 2 +/- 3 tab positions, respectively, whereas group SP lightened by a further 3 +/- 4 tab positions. There were no statistical differences between groups at day 14. CONCLUSIONS: Thirty-five per cent carbamide peroxide and 35% hydrogen peroxide were equally effective for intracoronal bleaching, and significantly better than sodium perborate after 7 days. After 14 days, there were no significant differences between the groups. Thirty-five per cent carbamide peroxide can be recommended as an equally effective alternative to hydrogen peroxide for intracoronal bleaching.     

Effect of tooth bleaching on bond strength of enamel-dentin cavities restored with silorane- and dimethacrylate-based materials

The aim of this study was to evaluate the influence of tooth bleaching on the push-out bond strength of a composite resin based on dimethacrylates and silorane to cavities that involve both enamel and dentin. A total of 80 bovine incisors were sectioned on the buccal surface to obtain specimens (10 × 10 mm) presenting enamel and dentin (1-mm thick each substrate). The specimens were randomly distributed into eight groups (n=10), according to the bleaching protocol (1--none; 2--10% carbamide peroxide [CP] for 21 days, six hours each day; 3--three applications of 35% hydrogen peroxide [HP] in 15-minute sessions, one session every seven days for three weeks; 4--10% CP for 18 days, six hours each day + three applications of 35% HP in 15-minute sessions, one session every seven days for three weeks) and the restorative system applied (Adper Single Bond 2 + Filtek Supreme; Filtek Silorane adhesive and composite resin). After treatment, cavities were made (1.2-mm diameter on dentin; 1.5-mm diameter on enamel) with a diamond bur. At 24 hours after restoration, a push-out bond strength test was performed at a crosshead speed of 0.5 mm/min. The bleaching treatments did not significantly affect the bond strengths of either restorative system to enamel-dentin. Regardless of the bleaching treatment, the dimethacrylate-based resin system exhibited significantly higher bond strengths to enamel-dentin than did the silorane-based system.     

Beyond冷光美白仪漂白氟牙症的疗效观察

目的 :评价Beyond冷光美白仪漂白氟牙症的疗效及安全性。方法 :用Beyond冷光美白仪及配套的冷光美白剂对实验组 30例患者 4 6 6个氟牙症牙进行漂白 ,对照组 30例患者 4 6 9个氟牙症牙以常规的盐酸脱色作对照。用VITA比色板作脱色前后比色 ,分析脱色效果 ,观察牙齿敏感情况。结果 :实验组的脱色显效率为 88.2 % ,对照组的显效率为 71.2 % ,两者有显著差异 (P <0 .0 1) ;实验组的脱色有效率为 99.4 % ,对照组的有效率为 99.4 % ,两者无显著差异 (P >0 .0 5 )。实验组有 8例 (2 6 .7% )患者牙齿有轻度酸痛不适感 ,对照组有17例 (5 6 .7% )患者出现不同程度的牙齿酸痛感 ,两者差异显著 (P <0 .0 1)。结论 :Beyond冷光美白仪对氟牙症牙脱色有效、安全、快速。