这项研究的目的是评估用短玻璃纤维增强树脂材料在人下颌前磨牙中修复的宫颈病变中心进入腔的骨折抵抗力。
收集60颗新鲜提取的人类下颌前磨牙,并将其分配到阳性对照组(G1-完整牙齿)和其他实验组(G2,G3。G4,G5,G6),传统的进入腔(TAC)和以宫颈病变为中心的进入腔(CLCAC)。牙髓治疗后,样本被相应地分组,G2-CLCAC无恢复(阴性对照),G3-CLCAC用常规纳米杂化复合材料(Tetric-N-Ceram)修复,G4-TAC用短玻璃纤维增强树脂复合材料(Ever-X后路)修复,G5-CLCAC用短玻璃纤维增强树脂复合材料(Ever-X后路)修复,G6-CLCAC用单独形成的单向纤维增强柱(Everstick柱)和短玻璃纤维增强树脂复合材料(Ever-X后柱)恢复。样品进行了热循环(35°C/28s,15°C/2s,35°C/28s,45°C/2s/10,000次循环)和周期性疲劳(2,50,000次循环/15-30N/2Hz),然后随后加载至失效。使用单向ANOVA和Tukey的后HOC检验对平均断裂载荷(牛顿)进行统计分析,并进行了失效模式分析。
与TAC设计相比,用纤维增强材料修复的CLCAC设计的平均抗断裂性较高,但差异无统计学意义。阴性对照组(CLCAC未修复)与除第3组(CLCAC用常规复合材料修复)外的所有其他组相比,显示出显着最小的抗骨折性(P<0.05)。
在研究的局限性内,可以得出结论,短玻璃纤维增强树脂复合材料改善了经牙髓治疗的下颌前磨牙的抗骨折性,而与进入腔设计的类型无关。在用短玻璃纤维增强复合材料修复的以宫颈病变为中心的进入腔中,可以看到更多的骨折。然而,这种设计在多根牙齿中的适用性,运河清洁功效,和长期的临床表现还有待探索,以补充这种新的访问设计。
The aim of this study was to evaluate the fracture resistance of cervical lesion centered access cavity restored with short glass fibre reinforced resin materials in human mandibular premolars.
Sixty freshly extracted human mandibular premolars were collected and assigned to positive control group (G1- Intact teeth) and other experimental groups (G2, G3. G4, G5, G6), Traditional Access Cavity(TAC) and Cervical Lesion Centered Access Cavity(CLCAC). Following endodontic therapy, samples were grouped accordingly, G2-CLCAC without restoration (Negative Control), G3-CLCAC restored with conventional nano-hybrid composite (Tetric-N-Ceram), G4-TAC restored with short glass fibre reinforced resin composite (Ever-X Posterior), G5-CLCAC restored with short glass fibre reinforced resin composite (Ever-X Posterior), G6- CLCAC restored with individually formed unidirectional fibre-reinforced post (Everstick post) and short glass fibre-reinforced resin composite (Ever-X Posterior). The samples were thermocycled (35 °C/28s, 15 °C/2s, 35 °C/28s, 45 °C/2s/10,000 cycles) and cyclically fatigued(2,50,000 cycles/15-30N/2 Hz) and then subsequently loaded to failure. The mean load to fracture (Newtons) were statistically analyzed using one-way ANOVA and Tukey\'s post HOC test and failure mode analysis was also done.
The mean fracture resistance of the CLCAC design restored with fibre reinforced materials was higher when compared to the TAC design but the difference was not statistically significant. The negative control group (CLCAC without restoration) showed significantly the least fracture resistance (P < 0.05) when compared to all the other groups except for group 3 (CLCAC restored with conventional composites).
Within the limitations of the study, it can be concluded that short glass fibre reinforced resin composites improved the fracture resistance of endodontically treated mandibular premolars irrespective of the type of access cavity designs. Favourable fractures were seen more in cervical lesion centered access cavity restored with short glass fibre reinforced composite materials. Nevertheless, the applicability of this design in multirooted teeth, canal cleanliness efficacy, and long term clinical performance are yet to be explored to complement this new access design.