PDF(Pubmed)
Abstract：
The evidence base on minimally invasive endodontic (MIE) treatment is limited. This study investigated the influence of MIE shaping on vertical root fracture (VRF) resistance and crack formation of root canal filled teeth. Human maxillary central incisors were randomized into six groups (n = 18, power = 0.9) and embedded in acrylic blocks with artificial periodontal ligaments. The root canals were either instrumented to size #40 and 0.04 taper (+MIE) or enlarged to ISO size #80 (-MIE). The canals were filled with cement-based (C) or adhesive resin-based (A) sealers in single-cone technique. The controls received no treatment or were left unfilled. After chewing simulation (staircase method, 25-150 N, 120,000×), the crack formation on the root surface was analyzed using stereomicroscope/digital imaging and classified (no defect, craze line, vertical crack, horizontal crack). Subsequently, the samples were loaded until fracture. The incidence of defects (56% vertical cracks) was not significantly different between the groups (p ≥ 0.077). VRF resistance was significantly higher in untreated teeth than in +MIE/C (p = 0.020) but did not significantly differ between the other groups (p ≥ 0.068). Minimal canal shaping did not reduce the risk of vertical root fracture and defects of root canal filled teeth.
摘要：
基于微创牙髓（MIE）治疗的证据有限。这项研究调查了MIE成形对垂直牙根断裂（VRF）阻力和根管填充牙齿裂纹形成的影响。将人上颌中切牙随机分为六组（n=18，幂=0.9），并嵌入带有人工牙周膜的丙烯酸块中。根管被安装到尺寸＃40和0.04锥度（MIE）或放大到ISO尺寸＃80（-MIE）。在单锥体技术中，用水泥基（C）或粘合剂树脂基（A）密封剂填充运河。对照没有接受治疗或没有填充。经过咀嚼模拟(楼梯法，25-150N,120,000×),使用立体显微镜/数字成像分析根部表面的裂纹形成并分类(无缺陷，crazeline,垂直裂纹,水平裂纹)。随后，加载样品直至断裂。两组之间的缺陷发生率（56％的垂直裂纹）没有显着差异（p≥0.077）。未经治疗的牙齿的VRF阻力显着高于MIE/C（p=0.020），但其他组之间没有显着差异（p≥0.068）。最小的根管成形并不能降低垂直根裂和根管填充牙齿缺损的风险。
