Tsintsadze Nino, Garcia Maria, Grandini Simone, Goracci Cecilia, Ferrari Marco
Am J Dent. 2015 Oct;28(5):251-4.
To assess the effect of three different drills used for post space preparation on fiber post retention after Reciproc endodontic treatment.
30 human upper incisors were endodontically treated using Reciproc and warm vertical gutta-percha compaction. Teeth were sealed coronally using Fuji VII, then stored in 0.5% T chloramine solution at 4 degrees C. After 1 week, teeth were randomly assigned to three groups (n = 10) that differed for the drill type used for post space preparation: Group 1: Calibrated drill; Group 2: Largo drill; Group 3: MTwo drill. Illusion posts were luted into the root canals using Gradia Core. After 24 hours, posted roots were transversally cut into 1 mm-thick slices for thin-slice post push-out testing. Two slices per apical, middle, and coronal thirds were obtained, resulting in a total of 6 slices per tooth. Thin-slice push-out test was conducted using a universal testing machine. Post push-out strength was measured in MPa. For the fracture analysis, the specimens were observed using a stereomicroscope at x40 magnification and classified as adhesive [between post-cement (P-C) or dentin-cement (D-C) interface], cohesive (within the post or adhesive cement) and mixed (adhesive and cohesive fractures occurred simultaneously). Between-group differences in post retentive strength were statistically analyzed (Kruskal-Wallis ANOVA, Dunn's Multiple Range test, P > 0.05). Differences in push-out strength among root levels within each group (one-way ANOVA or Kruskal-Wallis ANOVA, depending on the normality of data distribution, P> 0.05) and in failure mode distribution were also statistically evaluated (Fisher's Exact Test, P > 0.05).
For each group the mean of MPa values was: (1) 10.41 ± 3.56, (2) 10.98 ± 3.96, and (3) 12.11 ± 1.65. Failure mode was distributed as follows: Adhesive: (1) P-C - 23.3%, D-C - 21.7%; (2) P-C - 20%, D-C - 10%; (3) PrC - 46.7%, D-C - 13.3%; Cohesive: (1) 0.0%, (2) 3.3%; (3) 0.0%; Mixed: (1) 55.0%; (2) 66.7%; (3) 40.0%. The statistical analysis revealed the existence of significant between-group differences (P= 0.002). Group 3 measured significantly higher push-out strengths than Groups 1 and 2, which were comparable. Statistically significant between-group differences emerged also in failure mode distribution (P= 0.004). In Group 3 post-cement adhesive failures were significantly more frequent and mixed failures were significantly less frequent than in Group 2. No statistically significant differences emerged among the different root levels of the tested groups (P > 0.05).
评估三种不同的用于根管预备的钻针在使用Reciproc进行根管治疗后对纤维桩固位力的影响。
30颗人上颌切牙采用Reciproc和热垂直牙胶加压法进行根管治疗。用富士VII封闭牙冠，然后保存在4℃的0.5%氯胺T溶液中。1周后，将牙齿随机分为三组（n = 10），每组用于根管预备的钻针类型不同：第1组：校准钻针；第2组：Largo钻针；第3组：MTwo钻针。使用Gradia Core将幻像桩粘结到根管内。24小时后，将带桩的牙根横向切成1mm厚的薄片进行薄片桩推出试验。在根尖、中部和冠部三分之一处各取两片，每颗牙齿共6片。使用万能试验机进行薄片推出试验。桩的推出强度以MPa为单位测量。对于断裂分析，使用体视显微镜在40倍放大倍数下观察标本，并分为粘结性（桩-粘结剂（P-C）或牙本质-粘结剂（D-C）界面之间）、内聚性（桩内或粘结性粘结剂内）和混合型（粘结性和内聚性断裂同时发生）。对组间桩固位强度的差异进行统计学分析（Kruskal-Wallis方差分析，Dunn多重范围检验，P>0.05）。还对每组内不同牙根水平的推出强度差异（根据数据分布的正态性进行单向方差分析或Kruskal-Wallis方差分析，P>0.05）以及失效模式分布进行了统计学评估（Fisher精确检验，P>0.05）。
每组MPa值的平均值为：（1）10.41±3.56，（2）10.98±3.96，（3）12.11±1.65。失效模式分布如下：粘结性：（1）P-C - 23.3%，D-C - 21.7%；（2）P-C - 20%，D-C - 10%；（3）PrC - 46.7%，D-C - 13.3%；内聚性：（1）0.0%，（2）3.3%；（3）0.0%；混合型：（1）55.0%；（2）66.7%；（3）40.0%。统计分析显示组间存在显著差异（P = 0.002）。第3组的推出强度显著高于第1组和第2组，第1组和第2组相当。在失效模式分布上也出现了显著的组间差异（P = 0.004）。与第2组相比，第3组桩-粘结剂粘结性失效明显更频繁，混合型失效明显更少。测试组不同牙根水平之间未出现统计学显著差异（P>0.05）。
