【作者】 赵春晖；

【导师】 梅陵宣；

【作者基本信息】 安徽医科大学 ， 口腔临床医学， 2009， 硕士

【摘要】 目的应用染料渗透实验,比较System B和ObturaⅡ联合充填根管与冷牙胶侧方加压充填根管的根尖微渗漏情况及评价常用的三种牙体充填材料对根管冠向封闭能力的影响,为临床上选择更好的充填材料和方法提供实验依据。方法实验一:选取40颗新鲜拔除的上、下颌单根管恒牙,从颈部截冠,冠向下技术预备根管至40#,随机均分为A1、A2、B1、B2四组,A组采用System B和ObturaⅡ热牙胶充填技术充填根管,B组采用冷牙胶侧方加压充填技术充填根管,根管封闭剂选用AH-Plus糊剂(A1组、B1组)或国产氧化锌类根管充填剂(A2组、B2组),每组均设对照牙,只充填牙胶不使用根管封闭剂。通过2%亚甲蓝透明染色法,比较根尖区微渗漏情况,评价不同充填技术的根尖封闭能力。实验二:选取40颗新鲜拔除的上、下颌单根管恒牙,从颈部截冠,冠向下技术预备根管至40#,System B和ObturaⅡ热牙胶技术,配合AH-Plus糊剂充填根管,冠方横断面统一制备洞深为2mm,底平壁直的充填洞型,选用不同的充填材料,随机均分为四组,充填材料分别为:A(复合树脂)组、B(玻璃离子)组、C(银汞合金)组,对照(阳性对照—不充填窝洞,阴性对照—用粘蜡封闭窝洞)组。通过2%亚甲蓝透明染色法,比较常用充填材料对冠渗漏的影响,同时评价不同充填材料联合System B和ObturaⅡ热牙胶充填根管的冠向封闭能力。结果实验一:两种不同根管充填方法联合两种根管封闭剂均无法完全封闭根管。采用热垂直加压法根管充填组中,A1(AH-Plus糊剂)组所获得的染料渗透长度最短,平均为(1.84±0. 14 ) mm,A2(国产氧化锌类根管充填剂)组所获得的染料渗透长度平均为(1. 96±0. 17) mm,两组热塑牙胶间无统计学意义P > 0. 05。采用冷侧压法根管充填组中,B1(AH-Plus糊剂)组所获得的染料渗透长度平均为(2.16±0. 23) mm,B2(国产氧化锌类根管充填剂)组所获得的染料渗透长度平均为(2.89±0. 15) mm,两组冷牙胶间有统计学意义P﹤0. 05。将热垂直加压各组的染料渗透长度与冷侧压各组比较发现,热垂直加压各组的染料渗透长度明显较短,冷牙胶侧方加压法与热塑牙胶注射加压方法根尖微渗漏之间存在显著差异P < 0. 05。实验二:实验A,B,C组的平均染料渗透长度为(3. 34±0.16)mm,(3. 22±0. 21)mm,(3. 16±0.25)mm。渗漏按照由轻到重的顺序依次为银汞合金﹤玻璃离子﹤复合树脂。C组银汞合金(3. 16±0.25)mm的渗透距离较A,B组较短,A组复合树脂的渗透距离最长,但三种充填材料两两比较均无统计学差异( P > 0. 05)。阴性对照组根管内未见染料渗透,阳性对照组根管染料几乎达全长。结论1.在离体实验条件下,与冷牙胶侧方加压充填相比较,System B与ObturaⅡ联合根管充填技术具有较好的根管壁适应性和充填质量;2.采用冷侧压法进行根管充填时,树脂类根管封闭剂优于氧化锌类根管充填剂;而无论采用树脂类根管封闭剂还是采用氧化锌类根管封闭剂,热垂直加压根管充填法均可以显著提高根尖封闭性;3.充填物边缘密合性以银汞合金为最佳。经统计分析,它与复合树脂和玻璃离子相比无显著性差异。更多还原

【Abstract】 Objective The aim of this study was to draw a comparison on the apical microleakage by using dye penetration technique following endodontic therapy of teeth obturated by System B with ObturaⅡthermoplasticized gutta-percha injection and lateral condensation of cold gutta-percha in combination with different root canal sealers. And the coronal sealing ability of root canal obturation was assessed by using three different restorative materials. This vitro study was to provide the experimental basis for the choice of perfect restorative materials and filling technique in clinic.Methods Experiment one: the root canals of 40 extracted single-root teeth were prepared with crown-down technique, and randomly divided into four experimental groups, positive and negative controls. The teeth of four experimental groups were filled with two obturation techniques: System B with ObturaⅡthermoplasticized gutta -percha injection (Group A) and lateral condensation of cold gutta-percha (Group B). The root canal sealer was used with AH-Plus (Group A1, Group B1) and ZOE paste(Group A2, Group B2), and the specimens of positive and negative controls in each group were filled without any paste. The depth of dyeing lines were visualized and measured by using dye (methylthionine chloride) penetration and clearing technique. The data were analyzed by SPSS13.0 software to have a comparison on the apical microleakage among different groups of teeth. Then, the apical sealing ability of different filling technique was evaluated. Experiment two: the root canals of 40 extracted single-root teeth were prepared with crown-down technique, obturated by System B with obturaⅡthermoplasticized gutta -percha injection in combination with the AH-Plus paste. Then, the coronal surface were all prepared as standardized cavity with the depth of 2mm and flat walls. According to different restorative materials, the experimental teeth were randomly divided into four groups, which were named as group A(composite resin, CR), group B(glass ionomer ), group C (amalgam), positive and negative controls. The positive and negative controls were unfilled and filled with adhesive wax, respectively. The depth of dyeing lines were visualized and measured by using dye(methylthionine chloride) penetration and clearing technique. The data were analyzed by SPSS13.0 software to have a comparison on the coronal microleakage among different groups of teeth. Then, the effects of three restorative materials on coronal sealing ability were investigated.Results Experiment one: In warm gutta-percha obturation groups, dyeing lines of AH-Plus group had an average length of(1.84±0.14 ) mm, which was shortest in all groups. Dyeing lines of ZOE group had an average length of(1. 96±0.17) mm. There were no significant differences between AH-Plus group and ZOE group. In cold lateral condensation groups, dyeing lines of AH-Plus group had an average length of (2.16±0. 23) mm, which was significantly shorter than that of ZOE group (2.89±0.15) mm. However, the different results were observed in warm vertical condensation groups. Dyeing lines of each group showed similar length [(1.84±0. 14 ) mm to (1. 96±0.17) mm, P > 0. 05 ] , which were significantly shorter than that of cold lateral condensation groups ( P < 0. 05). Experiment two: The mean dyeing line lengths for experimental groups(A, B, C) were(3. 34±0.16)(3. 22±0.21)(3. 16±0.25)mm, respectively. The order of the microleakage for light serious level to serious level in three groups was: group C(amalgam)﹤group B (glass ionomer)﹤group A (CR). Composite resin(3. 34±0.16)mm had the longest penetration depth. Depth of amalgam(3. 16±0.25)mm was shorter than that of the former two groups, but there were no significant differences among them(P < 0. 05). No dyeing lines were observed in the negative controls, whereas the dyeing lines were nearly filled with all the teeth in the positive controls unfilled.Conclusions1, In vitro study, the injection-thermoplasticized gutta-percha technique had more excellent adaptation to canal wall and better quality of the root fillings compared with lateral condensation;2,When the root canals were filled by using cold lateral condensation technique, AH-Plus showed a better apical sealing ability than ZOE as the root canal sealer with less periapical microleakage. In addition, warm vertical condensation technique could dramatically eliminate periapical microleakage of root canals, irrespective of the sealers used;3,Amalgam had the best peripheral density and exhibited less microleakage than the other restoration materials tested (composite resin, glass ionomer), however, no significant statistic difference existed.更多还原