Pelozo Laís Lima, Silva-Neto Reinaldo Dias, Corona Silmara Aparecida Milori, Palma-Dibb Regina Guenka, Souza-Gabriel Aline Evangelista
School of Dentistry of Ribeirão Preto, University of São Paulo, Av. Café s/n, Monte Alegre, CEP 14040-904, Ribeirão Preto, São Paulo, Brazil.
Lasers Med Sci. 2019 Feb;34(1):47-54. doi: 10.1007/s10103-018-2579-5. Epub 2018 Jul 9.
Root-filled teeth that received fiber posts most frequently fail at the adhesive interface between resin cement and dentin. The objective of this study is to evaluate the effect of Er:YAG laser and/or sodium ascorbate (SA) on bond strength, microhardness of dentin, and penetration depth of cement into dentinal tubules. Forty-eight bovine incisor roots were endodontically treated, post spaces were prepared and equally divided into four groups (n = 12): G1-distilled water (control); G2-10% SA (10 min); G3-Er:YAG laser (150 mJ/4 Hz/40 s), and G4-Er:YAG laser + 10% SA. Glass fiber posts were cemented and roots sectioned into slices. In the first slice, the push-out bond strength (MPa) and failures were analyzed by confocal laser scanning microscope (CLSM). The second slice was subjected to microhardness test (KHN) and CLSM to assess the cement penetration. ANOVA and Tukey test were used for bond strength and microhardness data and Kruskal-Wallis and Dunn tests for the cement penetration (α = .05). The SA-treated samples had higher bond strength (10.02 ± 5.45a), similar to Er:YAG laser (9.91 ± 4.62a) and Er:YAG laser + SA (8.09 ± 4.07a). The least values (P < .05) were found on control (4.02 ± 2.39b). Significant differences were observed on root thirds (P < .05): cervical > middle > apical. There was a predominance of adhesive failures. The microhardness test revealed no differences between groups (P > .05). The experimental groups (G2, G3, and G4) had highest penetration into dentinal tubules when compared to the control (G1). Dentin pretreatments with Er:YAG laser or SA improved bond strength of cement-post-dentin interfaces; however, no synergistic effect of both treatments combined was observed.
进行根管充填的牙齿在使用纤维桩时，最常出现的失败情况发生在树脂水门汀与牙本质之间的粘结界面。本研究的目的是评估铒钇铝石榴石（Er:YAG）激光和/或抗坏血酸钠（SA）对粘结强度、牙本质显微硬度以及水门汀渗入牙本质小管深度的影响。选取48颗牛切牙牙根进行根管治疗，制备桩道后将其平均分为四组（n = 12）：G1-蒸馏水（对照组）；G2-10% SA（10分钟）；G3-Er:YAG激光（150 mJ/4 Hz/40秒），以及G4-Er:YAG激光 + 10% SA。粘结玻璃纤维桩后，将牙根切成薄片。在第一片中，通过共聚焦激光扫描显微镜（CLSM）分析推出粘结强度（MPa）和失败情况。对第二片进行显微硬度测试（KHN）并使用CLSM评估水门汀的渗入情况。对粘结强度和显微硬度数据使用方差分析（ANOVA）和Tukey检验，对水门汀渗入情况使用Kruskal-Wallis检验和Dunn检验（α = 0.05）。经SA处理的样本具有更高的粘结强度（10.02 ± 5.45a），与Er:YAG激光处理组（9.91 ± 4.62a）和Er:YAG激光 + SA处理组（8.09 ± 4.07a）相似。对照组的值最小（P < 0.05）（4.02 ± 2.39b）。在牙根的不同三分之一处观察到显著差异（P < 0.05）：颈部 > 中部 > 根尖部。主要为粘结失败。显微硬度测试显示各组之间无差异（P > 0.05）。与对照组（G1）相比，实验组（G2、G3和G4）渗入牙本质小管的程度最高。用Er:YAG激光或SA对牙本质进行预处理可提高水门汀 - 桩 - 牙本质界面的粘结强度；然而，未观察到两种处理联合的协同效应。
