Johar Aiman Othman
Oral and Maxillofacial Prosthodontics Department, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia, Phone: +966555665565, e-mail:
J Contemp Dent Pract. 2019 Feb 1;20(2):258-262.
To identify the incidence of accidental pulp exposure during the preparation of vital abutment tooth for porcelain- fused-to-metal (PFM) fixed prosthesis when prepared by undergraduate students.
A cohort study was conducted on 471 teeth, which were prepared to received PFM fixed partial denture, in patients between the age group of 20-40 years for 72 months. All the teeth were vital and healthy periodontally; preoperative radiographs were recorded. Measurements were taken from cone beam computed tomography (CBCT) scans of human extracted teeth for reference of the pulpal depths. Teeth with endodontic pulp exposure were documented and referred to the endodontic department.
In multivariate regression, when all variables were simultaneously considered and accounted for, tooth factors (arch and whether the tooth is anterior or posterior) and the distance between pulpal wall and cusp tip were significantly associated with odds of exposure ( = 0.006, 0.03 and < 0.0001). Maxillary and anterior were associated with higher odds of lateral exposure compared to mandibular and posterior teeth (OR = 10.34 and 3.53).
The present study draws the attention of the clinician towards the detrimental effect of tooth preparation on the vital pulp. The study concluded that maxillar and anterior teeth exposure has higher odds than mandibular and posterior teeth.
The undergraduate students must be trained to be extra careful while preparation of anterior and maxillary teeth for fixed partial dentures (FPD) to avoid pulpal exposure.
确定本科学生在为烤瓷熔附金属（PFM）固定义齿预备活基牙时意外穿髓的发生率。
对年龄在20至40岁之间的患者中准备接受PFM固定局部义齿修复的471颗牙齿进行队列研究，为期72个月。所有牙齿均为活髓且牙周健康；术前拍摄X线片。从人类拔除牙齿的锥形束计算机断层扫描（CBCT）图像中获取测量数据，以作为牙髓深度的参考。记录有牙髓暴露的牙齿，并转诊至牙髓科。
在多变量回归分析中，当同时考虑并分析所有变量时，牙齿因素（牙弓以及牙齿是前牙还是后牙）和髓壁与牙尖之间的距离与穿髓几率显著相关（P = 0.006、0.03和<0.0001）。与下颌牙和后牙相比，上颌牙和前牙发生侧穿的几率更高（OR = 10.34和3.53）。
本研究引起了临床医生对牙体预备对活髓的有害影响的关注。研究得出结论，上颌牙和前牙穿髓的几率高于下颌牙和后牙。
本科学生在为固定局部义齿（FPD）预备前牙和上颌牙时必须接受额外培训，以避免穿髓。
