Haralur Satheesh B, Alalyani Ahmed Fatis, Almutiq Mohammad Ali, Alfaifi Abdulrahman Ahmed, Al-Shehri Amer Abdullah
Department of Prosthodontics, College of Dentistry, King Khalid University, Abha, Kingdom of Saudi Arabia.
Intern Dentist, College of Dentistry, King Khalid University, Abha, Kingdom of Saudi Arabia.
Indian J Dent Res. 2018 Mar-Apr;29(2):206-211. doi: 10.4103/ijdr.IJDR_134_17.
The circumferential 2 mm ferrule during the fabrication of the crown is strongly advocated for the long-term clinical success. During the routine clinical practice, the dentist encounters the endodontically treated tooth (ETT) with inadequacy of the ferrule in some segment due to caries, abrasion, and erosions. The aim of this in vitro study was to investigate the consequence of inadequate segmental ferrule location on fracture strength of the root canal-treated anterior and posterior teeth.
Fifty each maxillary canine and mandibular premolar intact human teeth were root canal treated and sectioned at 2 mm above the cementum-enamel junction. The teeth samples were divided into 5 groups of 10 each. The G-I and G-V samples had the 360° ferrule and complete absence of the ferrule, respectively. The G-II had the inadequate ferrule on the palatal surface, while G-III and G-IV had inadequate ferrule at buccal and proximal area. Teeth samples were subsequently restored with glass-reinforced fiber post, composite core, and full veneer metal crown. The samples were tested with universal testing machine under static load to record the fracture resistance. The acquired data were subjected to ANOVA and Tukey's post hoc statistical analysis.
The G-I with circumferential ferrule showed the higher fracture resistance. The teeth samples with lack of the ferrule had the least fracture resistance. Among the segmental absence of ferrule, teeth samples with lack of the proximal ferrule were least affected. Deficiency of a ferrule on the lingual wall significantly affected the fracture strength in both anterior and posterior ETT.
The ETT with sectional inadequacy of the ferrule is significantly more effective in resisting the fracture in comparison to the complete absence of the ferrule.
在制作牙冠时，强力推荐使用2毫米的环形箍以确保长期的临床成功。在日常临床实践中，牙医会遇到因龋齿、磨损和侵蚀而导致箍在某些部位不足的根管治疗牙（ETT）。本体外研究的目的是调查节段性箍位置不足对根管治疗前后牙骨折强度的影响。
选取50颗上颌尖牙和50颗下颌前磨牙完整的人类牙齿进行根管治疗，并在牙骨质-釉质界上方2毫米处进行切片。牙齿样本分为5组，每组10颗。G-I组和G-V组样本分别有360°箍和完全没有箍。G-II组在腭侧表面箍不足，而G-III组和G-IV组在颊侧和近中区域箍不足。随后，用玻璃纤维增强桩、复合树脂核和全瓷金属冠对牙齿样本进行修复。使用万能试验机在静态载荷下对样本进行测试，以记录抗折强度。所获得的数据进行方差分析和Tukey事后统计分析。
有环形箍的G-I组显示出较高的抗折强度。没有箍的牙齿样本抗折强度最低。在箍节段性缺失中，近中箍缺失的牙齿样本受影响最小。舌侧壁箍的缺乏显著影响了前牙和后牙根管治疗牙的骨折强度。
与完全没有箍相比，箍节段性不足的根管治疗牙在抵抗骨折方面明显更有效。
