Coppla Fabiana-Madalozzo, Freire Andrea, Bittencourt Bruna, Armas-Vega Ana, Benítez Valeria-Elizabeth-Banderas, Calixto Abraham-Lincoln, Loguercio Alessandro-Dourado
DDS, Ms, PhD, professor, School of Dentistry, Health and Biosciences, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil.
DDS, Ms, PhD, professor, Department of Restorative Dentistry, School of Dentistry, State University of Ponta Grossa, Ponta Grossa, Paraná, Brazil.
J Clin Exp Dent. 2019 Jan 1;11(1):e21-e26. doi: 10.4317/jced.55153. eCollection 2019 Jan.
Bleaching procedures performed before restorative procedures, due to the oxygen released, affects the quality of bonding restorations. The application of an lower-concentrated antioxidant for one-hour or more can reversal the compromised bonding to bleached enamel, but it was not effective according to the bleaching concentrations applied. The aim of the present study was to evaluate simplified protocol of higher-concentrated sodium ascorbate (35%SA) in bond strength values of enamel bleached with 10%, 16%, 22% carbamide peroxide (CP) or 35% hydrogen peroxide (HP).
Three hundred and forty enamel surfaces of 85 human third molars were used, divided into 17 groups (n=20), according to the following groups: control = no bleaching and no ascorbic acid application; bleaching (CP10%, CP16%, CP22% at-home and HP 35% in-office) and 35%SA application (no application; 35%SA applied twice for 1-min each [SA2×1], twice for 5-min each [SA2×5] and; twice for 10-min each [SA2×10]). After that, adhesive was applied and composite cylinders were made with Filtek Z350 composite. Microshear test was performed in a universal testing machine. BS values were statistically evaluated using ANOVA and Tukey's and Dunnet's (against control) tests, with 5% level of significance.
All bleaching concentrations significantly decrease the enamel bond strength results when compared to control group (<0.05). More concentrated PC (PC22% and PH35%) showed lower enamel bond strength results when compared to lower concentrated PC (PC10% and PC16%; <0.05). A significant increase of the enamel bond strength results were only observed when SA2×5 and SA2×10 were applied (<0.05).
The application of 35% sodium ascorbate for twice 5- and 10-min each was an efficient protocol to reverse the bond strength in bleached enamel at the same level as the no bleaching enamel, independently of the bleaching concentration used. Tooth bleaching, hydrogen peroxide, sodium ascorbate, bond strength.
由于在修复操作前进行的漂白程序会释放氧气，这会影响粘结修复体的质量。应用低浓度抗氧化剂一小时或更长时间可恢复漂白牙釉质受损的粘结性能，但根据所应用的漂白浓度，该方法并不有效。本研究的目的是评估在使用10%、16%、22%过氧化脲（CP）或35%过氧化氢（HP）漂白的牙釉质粘结强度值中，高浓度抗坏血酸钠（35%SA）的简化方案。
使用85颗人类第三磨牙的340个牙釉质表面，根据以下分组分为17组（n = 20）：对照组 = 未漂白且未应用抗坏血酸；漂白组（家庭使用CP10%、CP16%、CP22%以及诊室使用HP 35%）和35%SA应用组（未应用；35%SA每次1分钟涂抹两次[SA2×1]，每次5分钟涂抹两次[SA2×5]，每次10分钟涂抹两次[SA2×10]）。之后，涂抹粘结剂并用Filtek Z350复合材料制作复合圆柱体。在万能试验机上进行微剪切试验。使用方差分析、Tukey检验和Dunnet检验（与对照组相比）对粘结强度值进行统计学评估，显著性水平为5%。
与对照组相比，所有漂白浓度均显著降低了牙釉质粘结强度结果（<0.05）。与低浓度PC（PC10%和PC16%）相比，更高浓度的PC（PC22%和PH35%）显示出牙釉质粘结强度结果更低（<0.05）。仅在应用SA2×5和SA2×10时观察到牙釉质粘结强度结果显著增加（<0.05）。
每次5分钟和10分钟各涂抹两次35%抗坏血酸钠是一种有效的方案，可使漂白牙釉质的粘结强度恢复到与未漂白牙釉质相同的水平，且与所使用的漂白浓度无关。牙齿漂白、过氧化氢、抗坏血酸钠、粘结强度。
