Galo Rodrigo, Marinho Mayara Terra, Telles Paloma Dias da Silva, Borsatto Maria Cristina
Department of Prosthodontics and Dental Materials, School of Dentistry of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
Department of Pediatric Clinics, Dental School of Ribeirão Preto, University of São Paulo, São Paulo, Brazil.
J Conserv Dent. 2021 Jul-Aug;24(4):393-398. doi: 10.4103/jcd.jcd_223_21. Epub 2022 Jan 13.
Lack of bond stability between the composite resin and dentin remains one of the main reasons for having to replace esthetic restorations.
This study aimed to evaluate the influence of chlorhexidine (CHX) on the bond strength of a total etching system to dentin tissue after degradation of the adhesive interface.
One hundred and eighty fragments of human molars were divided into three groups ( = 15) according to the materials used during the acid-etching step: Group 1 (control), 37% phosphoric acid; Group 2, a combined solution of 37% phosphoric acid and 2% CHX; and Group 3, 37% phosphoric acid followed by 2% CHX. Following the restorative procedures, the groups were divided into four subgroups according to the number of thermal cycles (TC) and to the time of storage in water (SW), and then subjected to a shear strength test, until fracture: (A) 0 TC/24-h SW; (B) 500 TC/1-week SW; (C) 2,000 TC/1-month SW; and (D) 12,000 TC/6-month SW. Two-way analysis of variance and Duncan's complementary test were used to perform multiple comparisons.
After the 24-h and 1-week SW time periods, no statistically significant difference was found among the shear strength values of the control and the experimental groups: 5.48 ± 0.59 MPa, 5.44 ± 0.56 MPa, and 5.65 ± 0.94 MPa for G1, G2, and G3, respectively. However, the shear strength values decreased significantly in all the study groups after 1 month, namely 3.60 ± 0.41 MPa, 3.08 ± 0.65 MPa, and 3.49 ± 0.23 MPa for G1, G2, and G3, respectively. After 6 months, similar results were found for G1 and G3, namely 2.77 ± 0.58 MPa and 1.74 ± 0.52 MPa, respectively, whereas the 0.77 ± 0.26 MPa value found for G2 was significantly lower than those found for the G1 and G3 groups. No differences were found between the groups with respect to fracture-type frequencies.
The use of CHX as an agent to rehydrate the dentin had a negative influence on bond strength.
复合树脂与牙本质之间缺乏粘结稳定性仍然是必须更换美观修复体的主要原因之一。
本研究旨在评估洗必泰（CHX）对粘结界面降解后全酸蚀系统与牙本质组织粘结强度的影响。
将180颗人类磨牙碎片根据酸蚀步骤中使用的材料分为三组（每组n = 15）：第1组（对照组），37%磷酸；第2组，37%磷酸与2%CHX的混合溶液；第3组，37%磷酸后接2%CHX。在进行修复程序后，根据热循环次数（TC）和在水中储存时间（SW）将各组再分为四个亚组，然后进行剪切强度测试，直至断裂：（A）0次TC/24小时SW；（B）500次TC/1周SW；（C）2000次TC/1个月SW；（D）12000次TC/6个月SW。采用双向方差分析和邓肯氏补充检验进行多重比较。
在24小时和1周的SW时间段后，对照组和实验组的剪切强度值之间未发现统计学上的显著差异：第1组、第2组和第3组分别为5.48±0.59MPa、5.44±0.56MPa和5.65±0.94MPa。然而，1个月后所有研究组的剪切强度值均显著下降，第1组、第2组和第3组分别为3.60±0.41MPa、3.08±0.65MPa和3.49±0.23MPa。6个月后，第1组和第3组得到类似结果，分别为2.77±0.58MPa和1.74±0.52MPa，而第2组的0.77±0.26MPa值显著低于第1组和第3组。各组在断裂类型频率方面未发现差异。
使用CHX作为使牙本质再水化的试剂对粘结强度有负面影响。
