Hoshino Isis Almela Endo, Dos Santos Paulo Henrique, Briso Andre Luiz Fraga, Sundfeld Renato Herman, Yamaguchi Satoshi, Rocha Eduardo Passos, Anchieta Rodolfo Bruniera
Department of Preventive Dentistry and Restorative Dentistry, São Paulo State University (UNESP), School of Dentistry, Araçatuba, SP, Brazil.
Department of Dental Materials and Prosthodontics, São Paulo State University (UNESP), School of Dentistry, Araçatuba, SP, Brazil.
J Prosthodont Res. 2023 Jan 6;67(1):103-111. doi: 10.2186/jpr.JPR_D_21_00253. Epub 2022 Mar 9.
The structural integrity of the resin cement layer, the bond strength, and the biomechanical behavior of different fiberglass post cementation techniques were evaluated.
Thirty-three bovine incisors were divided into three groups (n = 11): conventional fiberglass post (CFP), conventional fiberglass post in flared root canals (CFL), and relined fiberglass post (RFP). Six specimens from each group were submitted for high-resolution microcomputed tomography (μCT) to evaluate the integrity and presence/volume of voids at the resin cement layer. Finite element analysis (FEA) of two three-dimensional (3D) models of each group were conducted, one considered ideal (without interface defects) and another containing the conditions identified in the μCT analysis. Push-out bond strength tests were conducted for all specimens.
The CFL group had the greatest mean values of void (Thirds cervical: 73.67; middle: 95.67; apical: 47.33) and gap concentration (Thirds cervical: 14.67; middle: 15.83; apical: 8.33) compared with CFP and RFP. A significant difference in bond strength was observed between the cervical (1.33 MPa) and middle thirds (1.85 MPa) compared with the apical third (4.85 MPa) of the CFL. A significant difference was observed in the bond strength in the CFL (1.33 MPa) and RFP (3.29 MPa) in the cervical third, which were statistically similar to the bond strength of the CFP. The tensile stress distributions were similar in most structures, localized in the cervical region on the lingual surface.
Structural defects in the interface layer might influence the bond strength and biomechanical behavior under the different fiberglass post cementations.
评估不同玻璃纤维桩粘结技术下树脂粘结剂层的结构完整性、粘结强度及生物力学行为。
33颗牛切牙分为三组（n = 11）：传统玻璃纤维桩（CFP）、扩大型根管内的传统玻璃纤维桩（CFL）和衬里玻璃纤维桩（RFP）。每组取6个样本进行高分辨率显微计算机断层扫描（μCT），以评估树脂粘结剂层的完整性及孔隙的存在情况/体积。对每组的两个三维（3D）模型进行有限元分析（FEA），一个模型为理想模型（无界面缺陷），另一个模型包含μCT分析中确定的条件。对所有样本进行推出粘结强度测试。
与CFP和RFP相比，CFL组的孔隙（颈部三分之一处：73.67；中部：95.67；根尖部：47.33）和间隙集中程度（颈部三分之一处：14.67；中部：15.83；根尖部：8.33）的平均值最大。CFL组颈部（1.33MPa）和中部三分之一处（1.85MPa）的粘结强度与根尖三分之一处（4.85MPa）相比有显著差异。CFL组颈部三分之一处（1.33MPa）和RFP组（3.29MPa）的粘结强度有显著差异，这在统计学上与CFP组的粘结强度相似。大多数结构中的拉应力分布相似，集中在舌侧颈部区域。
界面层的结构缺陷可能会影响不同玻璃纤维桩粘结情况下的粘结强度和生物力学行为。
