Shafiei Fereshteh, Mehrzadi Mehrdad, Bakhshandeh Mohsen, Tavangar Maryam S
Gen Dent. 2023 Mar-Apr;71(2):43-47.
It has been shown that irradiation can cause structural changes in dentin that may reduce the bond strength of adhesives to dentin. Applying cross-linking or antioxidant agents may help reverse this detrimental effect and improve adhesion to dentin. This in vitro study aimed to evaluate the effects of epigallocatechin-3-gallate (EGCG) pretreatment and the time of adhesive bonding (24 hours vs 1 month) on the shear bond strength (SBS) of All-Bond Universal (ABU) to irradiated dentin using etch-and-rinse (ER) and self-etching (SE) modes. Flat dentin surfaces prepared from 96 extracted intact human molars were divided into 8 groups (n = 12) and bonded with ABU. In the control (CO) groups (CO/ER and CO/SE), bonding was performed on nonirradiated dentin; in the irradiated (IR) groups (IR/ER and IR/SE), bonding was performed on irradiated dentin; in the irradiated pretreated groups (IR/EGCG/ER and IR/EGCG/SE), irradiated dentin received a 0.1% EGCG pretreatment before bonding; and in the irradiated delayed bonding (DL) groups (IR/DL/ER and IR/DL/SE), bonding on irradiated dentin was performed 1 month after completion of radiotherapy. The irradiation protocol consisted of a total dose of 60 Gy with 2-Gy exposure applied 5 days per week for a period of 6 weeks. After bonding procedures were completed, the specimens were stored in 100% humidity at 37°C for 24 hours and then the SBS was tested in a universal testing machine. Data were analyzed using 1-way analysis of variance and Tukey tests. There was a statistically significant difference among the 8 groups (P < 0.001). Irradiation diminished the SBS in the IR/ER and IR/SE groups compared with their controls (P < 0.001). Pretreatment with EGCG significantly increased the SBS in the IR/EGCG/ER group only (P < 0.001). The difference between the IR/ER and IR/DL/ER groups was not statistically significant, and the difference between the IR/SE and IR/DL/SE groups was marginally significant (P = 0.056). Pretreatment with EGCG after acid etching restored the SBS of ABU to irradiated dentin, resulting in an adhesive performance equivalent to that observed with nonirradiated dentin. A 1-month delay between irradiation and bonding did not improve the SBS.
研究表明，辐照可导致牙本质结构发生变化，这可能会降低粘合剂与牙本质之间的粘结强度。应用交联剂或抗氧化剂可能有助于逆转这种有害影响，并改善与牙本质的粘结。这项体外研究旨在评估表没食子儿茶素-3-没食子酸酯（EGCG）预处理以及粘结时间（24小时与1个月）对全粘结通用型粘结剂（ABU）在蚀刻冲洗（ER）和自酸蚀（SE）模式下与辐照牙本质的剪切粘结强度（SBS）的影响。从96颗完整拔除的人磨牙制备的平坦牙本质表面分为8组（n = 12），并用ABU进行粘结。在对照组（CO）（CO/ER和CO/SE）中，在未辐照的牙本质上进行粘结；在辐照组（IR）（IR/ER和IR/SE）中，在辐照后的牙本质上进行粘结；在辐照预处理组（IR/EGCG/ER和IR/EGCG/SE）中，辐照后的牙本质在粘结前接受0.1%的EGCG预处理；在辐照延迟粘结组（IR/DL/ER和IR/DL/SE）中，在放疗完成1个月后在辐照后的牙本质上进行粘结。辐照方案包括总剂量60 Gy，每周5天，每次照射2 Gy，持续6周。粘结程序完成后，将标本在37°C、100%湿度下保存24小时，然后在万能试验机上测试SBS。数据采用单因素方差分析和Tukey检验进行分析。8组之间存在统计学显著差异（P < 0.001）。与对照组相比，辐照降低了IR/ER和IR/SE组的SBS（P < 0.001）。仅EGCG预处理显著提高了IR/EGCG/ER组的SBS（P < 0.001）。IR/ER组和IR/DL/ER组之间的差异无统计学意义，IR/SE组和IR/DL/SE组之间的差异边缘显著（P = 0.056）。酸蚀后用EGCG预处理可恢复ABU与辐照牙本质的SBS，使其粘结性能与未辐照牙本质相当。辐照与粘结之间延迟1个月并未提高SBS。
