Department of Oral Special Consultation, The Affiliated Stomatological Hospital of Nanjing Medical University, Nanjing, PR China; Jiangsu Province Key Laboratory of Oral Diseases, Nanjing, PR China; Jiangsu Province Engineering Research Center of Stomatological Translational Medicine, Nanjing, PR China.
Department of Stomatology, Jinling Hospital, Clinical School, Medical College, Nanjing University, Nanjing, PR China.
J Dent. 2023 Nov;138:104685. doi: 10.1016/j.jdent.2023.104685. Epub 2023 Sep 1.
The purpose of this in vitro study was to evaluate the internal adaptation, fracture resistance, and fracture pattern of the residual roots and crowns of molars restored with computer-aided design/computer-aided manufacturing (CAD/CAM) glass fiber post-cores, and compare them with three other post-core restorations.
We selected 32 extracted maxillary first molars and divided them into four groups according to the post-core system: traditional casting titanium (Ti) post-cores (TC group); Ti post-cores fabricated with selective laser melting (SLM group); CAD/CAM glass fiber post-cores of the split type (CCS group); and prefabricated glass fiber posts and composite resin cores (PF group). The internal adaptation was analyzed with microcomputed tomography. Teeth were restored with monolithic zirconia crowns and subjected to thermocycling and cyclic loading. A load was applied consistently along the long axis of the tooth until fracture to record the fracture resistance and pattern. For the statistical analysis, one- and two-way analyses of variance, Tukey's post hoc and chi-square tests were performed to compare the differences among the groups.
The CCS, TC, and SLM groups exhibited similar internal adaptations across all sections (P < 0.05). The FP group showed good fit with the root canals in the apical and middle sections but a poor fit with those in the cervical section. The fracture resistance was higher in the CCS, TC, and SLM groups compared to the PF group (P < 0.05). The proportions of restorable fractures in the CCS and PF groups were 62.5% and 50%, respectively. Unrestorable fractures were more frequent in the TC and SLM groups at frequencies of 100% and 87.5%, respectively.
The internal adaptation and fracture resistance of the CCS group were similar to those of the TC and SLM groups, and the fracture pattern was mostly restorable, thus meeting the clinical requirements for molar post-core restorations.
CCS can be used to restore residual roots and crowns of molars and exhibit high efficacy in terms of adaptability and mechanical properties. More studies are required to evaluate the effectiveness of CCS.
本体外研究旨在评估经计算机辅助设计/计算机辅助制造（CAD/CAM）玻璃纤维桩核修复后的磨牙残根和残冠的内部适应性、抗折强度和折裂模式，并将其与其他三种桩核修复方法进行比较。
我们选择了 32 颗上颌第一磨牙，并根据桩核系统将其分为四组：传统铸造钛（Ti）桩核（TC 组）；选择性激光熔化（SLM）制作的 Ti 桩核（SLM 组）；分体式 CAD/CAM 玻璃纤维桩核（CCS 组）；预制玻璃纤维桩和复合树脂核（PF 组）。使用微计算机断层扫描分析内部适应性。用整体氧化锆冠修复牙齿，并进行热循环和循环加载。沿牙齿长轴持续施加一致的载荷直至折断，以记录抗折强度和折裂模式。采用单因素和双因素方差分析、Tukey 事后检验和卡方检验进行统计分析，以比较各组间的差异。
CCS、TC 和 SLM 组在所有节段的内部适应性相似（P<0.05）。FP 组在根尖和中段与根管的适配性较好，但在颈段与根管的适配性较差。CCS、TC 和 SLM 组的抗折强度均高于 PF 组（P<0.05）。CCS 和 PF 组的可修复折裂比例分别为 62.5%和 50%。TC 和 SLM 组的不可修复折裂比例分别为 100%和 87.5%。
CCS 组的内部适应性和抗折强度与 TC 和 SLM 组相似，折裂模式多为可修复性，符合磨牙桩核修复的临床要求。
CCS 可用于修复磨牙残根和残冠，在适应性和机械性能方面具有较高的疗效。需要更多的研究来评估 CCS 的有效性。
