【作者】 包玮玮；

【导师】 程辉；

【作者基本信息】 福建医科大学 ， 口腔临床医学， 2008， 硕士

【摘要】 目的研究Pontic制作的纤维根管桩与五种根管桩的弯曲强度和弯曲模量,并研究成品玻璃纤维根管桩和Pontic自制纤维根管桩的剪切粘结强度,为Pontic制作纤维桩的临床应用提供理论基础。方法(1)在自制的玻璃模具上,采用Pontic制作纤维根管桩。(2)用三点弯曲的方法,在Pontic自制纤维根管桩的中央加载,加载速度为1.0mm/min,直至试样断裂,记录最大载荷值。在同条件下测试不同直径的成品玻璃纤维根管桩、成品氧化锆根管桩、成品不锈钢根管桩、成品钛合金根管桩和铸造Ni-Cr合金根管桩的最大载荷,进行各种根管桩弯曲强度和弯曲模量的比较。(3)选取20颗新鲜完整离体上颌中切牙,经根管治疗、根管预备后随机分为两组,成品玻璃纤维根管桩和Pontic自制纤维根管桩组。两组均用Rely X Unicem粘结剂将纤维桩粘于根管内。经慢速切割机连续切割出厚度为1.5mm的三片薄片S1, S2和S3后,用微推出的方法,在纤维桩中央加载,直至纤维桩完全从根管中推出,加载速度为0.5mm/min,记录最大载荷值。(4)采用双因素方差分析和单因素方差分析对实验结果进行统计处理。结果(1)各种根管桩弯曲强度的范围分别是:Pontic自制纤维根管桩为585~ 616MPa,成品玻璃纤维根管桩为519~1081MPa,成品氧化锆根管桩为939~1265 MPa,成品不锈钢根管桩为1649~2265MPa,成品钛合金根管桩为1411~2156MPa,铸造Ni-Cr合金根管桩为1336~1949MPa;经双因素方差分析各测试组的弯曲强度有显著性差异(P<0.05)。(2)各种根管桩弯曲模量的范围分别是:Pontic自制纤维根管桩为16~20GPa,成品玻璃纤维根管桩为21~36GPa,成品氧化锆根管桩为74~125GPa,成品不锈钢根管桩为32~98GPa,成品钛合金根管桩为42~63GPa,铸造Ni-Cr合金根管桩为34~98GPa;经双因素方差分析各测试组的弯曲模量有显著性差异(P<0.05)。(3)成品玻璃纤维桩的剪切粘结强度为8.61±3.33MPa,Pontic自制纤维根管桩的剪切粘结强度为6.36±3.05MPa,两种纤维桩的剪切粘结强度有显著性差异(P<0.05)。在S1段,成品玻璃纤维根管桩的剪切粘结强度为8.08±3.61MPa,Pontic自制纤维根管桩为8.13±3.32MPa;在S2段,成品玻璃纤维根管桩的剪切粘结强度为9.32±4.06MPa,Pontic自制纤维根管桩为6.79±2.96MPa;在S1和S2段,两种纤维桩的剪切粘结强度均无显著性差异(P>0.05)。在S3段,成品玻璃纤维根管桩的剪切粘结强度为8.44±2.34MPa,Pontic自制纤维根管桩为4.19±1.22MPa,两种纤维桩的剪切粘结强度有显著性差异(P<0.05)。结论(1)金属根管桩拥有较高的弯曲强度,氧化锆根管桩次之,纤维根管桩的弯曲强度较低,各组根管桩的弯曲强度均达到临床使用要求。(2)弯曲模量最高的是氧化锆根管桩,其次为金属根管桩,纤维根管桩的较低,两种纤维根管桩的弯曲模量与牙本质较匹配,有利于保护牙根。(3)应用Rely X Unicem粘结剂,成品玻璃纤维根管桩和Pontic自制纤维根管桩与根管形成良好粘结。更多还原

【Abstract】 Objective The aim of this study was to investigate the flexural strength and the flexural modulus of 6 kinds root canal post and the bond strength of 2 kinds of fiber reinforced root canal post, and to provide theoretical ground for applying Pontic fiber post to clinical use.Methods (1) Pontic fiber posts were made by self-made glass pattern; (2) Pontic fiber posts were loaded to failure in a three-point bending test. The crosshead speed is 1.0 mm/min. The same test repeated with glass fiber posts, zirconia posts, Ni-Cr alloy cast posts, stainless steel posts and titanium posts; (3) Twenty extracted human maxillary central incisors were selected and then canines were endodontically treated. Following standardized post space preparations, teeth were divided into two equal groups, and then glass fiber posts and Pontic fiber posts were placed in the treated canines using Rely X Unicem. Three slices of 1.5mm height were cut perpendicular to the post from each restored root. The bond strength was determined by pushing out test. The crosshead speed is 0.5 mm/min. (4)Data were statistically analyzed using two-way analysis of variance(ANOVA) and one-way analysis of variance.Results (1) The ANOVA test analysis revealed significant differences between groups (P < 0.05) for flexural strength mean values. Yield flexural strength of the 6 kinds post as follows:Pontic fiber post were 585 to 616MPa, glass fiber post were 519 to 1081MPa, zirconia post were 939 to 1265MPa, stainless steel posts were 1649 to 2265Mpa, titanium posts were 1411 to 2156MPa, Ni-Cr alloy cast posts were 1336 to 1949MPa. (2)The ANOVA test analysis revealed significant differences between groups (P < 0.05) for flexural modulus mean values. Yield flexural modulus of the 6 kinds post as follows: Pontic fiber posts were 16 to 20Gpa, glass fiber posts were 21 to 36GPa, zirconia posts were 74 to 125GPa, stainless steel posts were 32 to 98GPa, titanium posts were 42 to 63GPa, Ni-Cr alloy cast posts were 34 to 98GPa. (3) The ANOVA test analysis revealed significant differences between the two group in mean bond strengths (P>0.05), the bond strength for glass fiber post was 8.61±3.33MPa, and for Pontic fiber post was 6.36±3.05MPa. At the coronal third, the ANOVA test analysis revealed significant differences between the two post, the bond strength of glass fiber post was 8.44±2.34MPa, that of Pontic fiber post was 4.19±1.22MPa (P < 0.05); at the middle third and the apical third, the ANOVA test analysis revealed no statistically significant difference in mean bond strengths (P>0.05), at the middle third, the bond strength of glass fiber post was 9.32±4.06MPa, that of Pontic fiber post was 6.79±2.96MPa; at the apical third, the bond strength of glass fiber post was 8.08±3.61MPa, that of Pontic fiber post was 8.13±3.32MPa.Conclusions (1) The metal post has the highest flexural strength recorded, the next is zirconia post, fiber post is lower. Flexural strength of the 6 kinds post can meet clinical requirement. (2) Zirconia post had the highest flexural strength recorded, the next is those metal post, fiber post is lower. The flexture modulous of fiber post is more matching that of dentin. (3) Using Rely X Unicem, both glass fiber post and Pontic fiber post form good bond strength to dentin.更多还原