Tian H Y, Yu P, Yuan C Y, Zhang W, Qiu Y X, Li D H, Liang X J, Wang X Y
Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
AT&M Biomaterial Co., Ltd, Beijing 100094, China.
Beijing Da Xue Xue Bao Yi Xue Ban. 2016 Oct 18;48(5):889-893.
To compare the durability of resin-based root-surface coating material and all-in-one self-etching adhesive on root surface in vitro.
Human extracted premolars or molars with intact roots were selected. The cementum was removed using a periodontal scaler to expose root dentin. The root surface was coated with an acid-resistant nail varnish, leaving a window of 3 mm×3 mm on the exposed dentin.The window was covered with either PRG Barrier Coat (PRG) or Clearfil S3 Bond (CS3). After water aging for 14 d, specimens were immersed in acid buffer at pH 4.5 for 4 d and the demineralization buffer was changed every 24 h. Then the specimen was split longitudinally through the center of the 'window' and the cross-sectional surface was observed with scanning electron microscope (SEM). After fixed and dehydrated, the prepared samples were coated with platinum. The coating material, root dentin and the interface was observed by scanning electron microscope (SEM). The thickness of the coating material was measured on the SEM images. Regarding toothbrush wear test, coronal dentindisks were prepared and covered with PRG and CS3, respectively. After storage in water for 24 h, the specimen was subjected to the toothbrush wear tester for 100, 200, 300, 500, 700, 1 500 brushing cycles. A slurry of fluoride toothpaste (1:2 ratio of toothpaste and deionized water by weight) was used and the brushing load was 300 N. The surface microstructure of remaining coating material was analyzed using SEM. The wear depths were determined by a profilometer. Statistical analysis was performed with SPSS 20.0 by one-way ANOVA. The level of significance was at 0.05.
Application of PRG Barrier Coat produced a coating layer of (47.1±27.3) μm, while CS3 presented a thin film of (5.7±2.1) μm in thickness. The exposed dentin was hermetically sealed and no obvious gap was observed at the interface in both PRG and CS3 groups. There was no dentin demineralization observed in both groups after water aging. The wear depths of PRG and CS3 increased along with the numbers of brushing cycles. PRG wore at a significant lower pace than CS3 did (P<0.05).
PRG coating resin had similar performances as CS3 on protecting root dentin from demineralization after water aging. What's more, PRG demonstrated a higher toothbrush wear resistance than CS3. We concluded that PRG Barrier Coat contained S-PRG filler may be an effective coating material for protecting exposed root from both chemical and mechanical challenges. Further studies should be carried out to evaluate the long-term reliability of the rootsurface coating materials under the clinical setting.
在体外比较树脂基根面涂层材料和一体化自酸蚀粘结剂在根面上的耐久性。
选取具有完整牙根的人拔除前磨牙或磨牙。使用牙周洁治器去除牙骨质以暴露根面牙本质。在根面涂上耐酸指甲油，在暴露的牙本质上留下一个3mm×3mm的窗口。该窗口分别用PRG屏障涂层（PRG）或Clearfil S3粘结剂（CS3）覆盖。水老化14天后，将标本浸入pH值为4.5的酸性缓冲液中4天，每24小时更换一次脱矿质缓冲液。然后将标本沿“窗口”中心纵向劈开，用扫描电子显微镜（SEM）观察横截面。固定和脱水后，制备的样品镀铂。用扫描电子显微镜（SEM）观察涂层材料、根面牙本质及界面。在SEM图像上测量涂层材料的厚度。关于牙刷磨损试验，制备冠部牙本质盘，分别用PRG和CS3覆盖。在水中储存24小时后，将标本置于牙刷磨损试验机上进行100、200、300、500、700、1500次刷牙循环。使用含氟牙膏浆液（牙膏与去离子水重量比为1:2），刷牙负荷为300N。用SEM分析剩余涂层材料的表面微观结构。用轮廓仪测定磨损深度。使用SPSS 20.0进行单因素方差分析统计分析。显著性水平为0.05。
应用PRG屏障涂层产生的涂层厚度为（47.1±27.3）μm，而CS3呈现厚度为（5.7±2.1）μm的薄膜。暴露的牙本质被完全密封，PRG组和CS3组在界面处均未观察到明显间隙。水老化后两组均未观察到牙本质脱矿。PRG和CS3的磨损深度随刷牙循环次数增加。PRG的磨损速度明显低于CS3（P<0.05）。
PRG涂层树脂在水老化后保护根面牙本质免受脱矿方面与CS3具有相似性能。此外，PRG表现出比CS3更高的牙刷耐磨性。我们得出结论，含有S-PRG填料的PRG屏障涂层可能是一种有效的涂层材料，可保护暴露的牙根免受化学和机械损伤。应进一步开展研究以评估根面涂层材料在临床环境下的长期可靠性。
