Immediate and Delayed Repair of 2 Sizes of Furcal Perforations in Dogs' Teeth Using Mineral Trioxide Aggregate Cement.

INTRODUCTION: This histologic study aimed to measure the morphometric and morphologic changes in periodontal tissue after immediate and delayed mineral trioxide aggregate (MTA) repair of 2 sizes of furcal perforations. METHODS: There were 72 premolars from 12 beagle dogs that were divided equally into 4 experimental and 2 control groups (n = 12). Experimental groups included immediate small (0.6 mm in diameter), immediate large (1.8 mm in diameter), delayed (30 days) small, and delayed large furcal perforation MTA repair. The control groups included negative (no furcal perforation) and positive (nonrepaired small and large furcal perforations) controls. After 3 months, tissue blocks were harvested and processed for histologic assessment. Morphometric analysis measured the thickness of periodontal ligaments (average, maximum, and minimum) in millimeters, the area of interest in square millimeters, and the area of healing tissue at the perforation site in square millimeters. Morphologic assessment consisted of 7 parameters for tissue inflammation, resorption, and repair. Histologic assessment was completed by 2 calibrated examiners who were blinded to the study group. RESULTS: Morphometric and morphologic measurements showed no significant difference between immediate and delayed MTA repair of small perforations and the negative control. The average thickness of the periodontal ligaments in delayed large perforations was 0.467 mm, which was significantly different from 0.294 mm in the delayed small perforations repair. The area of healing tissue in the positive control was 0.473 mm2, which was significantly different from 0.311 mm2 in delayed large perforation repair. CONCLUSIONS: Within the study limitations, periodontal tissue responded more favorably to MTA repair of furcal perforation when it was placed in smaller perforations. The time of treatment became more critical as the perforation size increased.

Single-visit endodontic treatment of mature teeth with chronic apical abscesses using mineral trioxide aggregate cement: a randomized clinical trial.

BACKGROUND: Mature teeth with chronic apical abscesses characterized by intermittent discharge of pus through an associated sinus tract. This communication between oral mucosa and periapical inflammation is challenging for the sealing ability of root canal obturation material. Therefore, the study aim was to compare the outcomes of endodontic treatment using mineral trioxide aggregate (MTA) cement to the conventional gutta-percha cone and root canal sealer as an obturation material in mature teeth with chronic apical abscesses. METHODS: Mature teeth with chronic apical abscesses referred to our clinic for root canal treatment between 2010 and 2012 were treated in a single visit and distributed among treatment (T) and control (C) groups using a predetermined randomization block (TCTC). After chemo-mechanical preparation, teeth in group T received MTA cement mixed in a 0.26 water to powder ratio, and teeth group C received gutta-percha and root canal sealer using the warm vertical technique. The treatment outcomes were defined as obturation length, periapical healing, resorption of extruded material, and survival rate at least 2.5 years after treatment. Three endodontists blinded to the type of obturation material documented treatment outcomes. Statistical analysis at P < 0.05 was conducted to measure difference between the groups. RESULTS: Thirty-six teeth were treated between 2010 and 2012, and 32 teeth were evaluated in 2015. Complete periapical healing was observed in 87.5 % of MTA-treated teeth and 75.0 % of gutta-percha-treated teeth. Adequate obturation length was reported in 50.0 % of MTA-treated and 37.5 % of gutta-percha-treated teeth. Complete resorption of extruded material was evident in 83.3 % MTA-treated teeth and 100.0 % gutta-percha-treated teeth. The survival rate of MTA-treated teeth was 100 % at 3, and 5 years, while the survival rate of gutta-percha-treated teeth was 83.3 % at 3, and 5 years. There was no significant difference between the groups in term of periapical healing, survival rate, obturation length, or resorption of extruded material. CONCLUSIONS: The outcomes of single-visit endodontic treatment of mature teeth with chronic apical abscesses using MTA cement were better, but not statistically significant, compared to conventional treatment. TRIAL REGISTRATION: ISRCTN15285974 . Registered retrospectively 23 June 2015.

Effects of Clinical Training and Case Difficulty on the Radiographic Quality of Root Canal Fillings Performed by Dental Students in Saudi Arabia.

INTRODUCTION: The aim of this study was to evaluate the effects of training duration and case difficulty on the radiographic quality of root canal fillings performed by dental students in Saudi Arabia. METHODS AND MATERIALS: A longitudinal cohort study was conducted at King Saud University. Root canal treatments performed by 55 dental students from 2012-2014 were included in the study. Each student treated at least five teeth during the first year of clinical endodontic training and another five teeth during the second year. Case difficulty was assessed based on tooth position in the dental arch and preoperative conditions. The radiographic quality of the root canal filling was evaluated by two endodontists blinded to treatment completion date. The evaluation criteria were adequate obturation, presence of mishaps and preparation taper. The data were statistically analysed using univariate and multivariate logistic regression analyses; and the level of significance was set at 0.05. RESULTS: Inadequate obturation and mishaps were significantly less prevalent in teeth treated after 2 years of clinical training. The odds ratios for inadequate obturation and mishaps increased significantly as tooth position moved posteriorly. Inadequate obturation and more mishaps were significantly more prevalent in teeth with preoperative conditions. Preparation taper was not significantly affected by training duration or case difficulty. CONCLUSION: The quality of root canal fillings performed by Saudi students was adversely affected by case difficulty. The radiographic quality of root canal fillings improved significantly after 2 years of clinical training. Preparation taper outcome is likely dependent on the preparation technique and instrument taper.