Fracture resistance of roots filled with three different obturation techniques

Objectives: The aim of this study was to compare in vitro root fracture resistance following root canal filling with AH 26 using lateral condensation, BeeFill, and Thermafil techniques. Study Design: Eighty extracted human mandibular premolars with similar dimensions were selected. In order to standardize the roots, measurements were taken in two separate regions of the teeth—at the cemento-enamel junction and 8 mm apically from the junction—buccolingual as well as mesiodistal for every tooth. Teeth were then randomly divided into five groups (n=16). With the exception of the non-prepared group (Group 1), instrumentation was done in all groups. In group 2, instrumentation but no filling was performed; in group 3, the obturation was done with AH 26 + gutta-percha; in group 4, with AH 26 + BeeFill and in group 5, AH 26 + a Thermafil obturator was used. All the roots were mounted vertically in copper rings and filled with acrylic resin, exposing 8 mm of the coronal part. A universal testing machine was used for the strength test. Results: The results were analyzed using the one-way ANOVA test. The significance between the groups was tested with Temhane’s T2 test. The results indicate that instrumentation of root canals had a significant effect on fracture resistance (p<0.05). In addition, there were no differences between the root canal obturation techniques; furthermore, these techniques did not create a statistically important resistance to vertical fracture (p>0.05). Conclusions: The results suggest that instrumentation of root canals significantly weakens the tooth structure to fracture and the root canal obturation techniques that are used are not able to form reinforcement. Key words:AH 26, obturation technique, vertical fracture.     

Minimal intervention concept: a new paradigm for operative dentistry

The current treatment philosophy is to prevent and detect dental disease at the earliest stage in order to avoid invasive treatment. With the current understanding of the nature of dental disease and its process, the treatment philosophy is now changing to a more conservative approach and the concept of minimal intervention is gaining popularity in modern dentistry throughout the world. It is now established that demineralized but non-cavitated enamel and dentine can be healed and traditional surgical approach of drilling and filling may no longer be necessary as this only treats the symptoms of the disease and not the cause. However, when surgical intervention is indicated, the least invasive techniques such as preventive resin restoration and minimal cavity preparation are utilized. The aim of this article is to give dental professionals an overview of the concepts of minimal intervention dentistry and recent innovations in dental technology in both the diagnosis and treatment of dental caries.     

Increased carotid intima-media thickness is associated with higher SYNTAX score

The main purpose of this study was to investigate the relation between carotid intima-media thickness (CIMT) and coronary artery disease (CAD) complexity. Consecutive patients (n = 360) with CAD confirmed by coronary angiography were enrolled. Mean CIMT and the overall SYNTAX score (SXscore) were 0.87 ± 0.12 mm and 15 ± 9, respectively. In univariate analysis, there was a significant correlation between the overall SXscore and CIMT (r = .42, P < .001), age (r = .23, P < .001), hypertension (r = .27, P = 0.001), diabetes (r = 0.11, P = 0.02), smoking (r = .24, P = .01), dyslipidemia (r = .2, P = 0.03), and β-blocker use (r = .19, P < .001). In multivariate analysis, CIMT (β = .34, P < .001) and age (β = .11, P < .019) were independently associated with SXscore. We have demonstrated a significant relation between CIMT and SXscore. Although this study is correlative and no causative conclusions can be drawn, our findings suggest that increased CIMT could reflect complex coronary artery lesions.     

Nonsense β-thalassemia mutation at codon 37 (TGG>TGA), detected for the first time in three Turkish cases

Thalassemias are genetically heterogeneous group of disorders with reduced or absent production of globin. β-Thalassemia major can be caused by homozygosity or compound heterozygosity for β-globin gene mutation. Here we report, for the first time in Turkey, three cases who carry the nonsense β-thalassemia (β-thal) mutation at codon 37 (TGG>TGA; Trp→Stop) causing premature stop codon.     

Effect of Agitation of EDTA with 808-Nanometer Diode Laser on Removal of Smear Layer

Introduction

Near-infrared diode lasers can be used for several applications, which range from disinfection to smear layer removal in endodontics. This study evaluated the efficacy of agitation of 15% EDTA with an 808-nm diode laser on removal of the smear layer.

Methods

Sixty extracted human maxillary central incisor teeth were instrumented up to ProTaper F4 (Dentsply Maillefer, Ballagues, Switzerland) and then randomly divided into 6 groups (n = 10 for each group) according to the different final irrigating protocols as follows: 5% sodium hypochlorite for 120 seconds performed with the NaviTip (Dentsply Maillefer, Ballaigues, Switzerland) (control group); 15% EDTA for 120 seconds performed with the NaviTip; and agitation of 15% EDTA with an 808-nm diode laser for 10, 20, 30, and 40 seconds. Specimens were observed under a scanning electron microscope, and open dentinal tubules were counted using Adobe Photoshop software (Adobe Systems, San Jose, CA). The data were analyzed with 1-way analysis of variance and Tukey post hoc tests (P = .05).

Results

The number of open dentinal tubules was higher in the middle thirds than in the apical thirds. The differences between the apical and middle thirds were statistically significant (P < .05). Statistically significant differences were also found between the control group and the other groups in both the middle and apical thirds of the root canals (P < .05).

Conclusions

The results indicated that agitation of 15% EDTA with an 808-nm diode laser for 20 seconds was effective in removing the smear layer in the apical thirds of root canals.     

Effects of severity and location of nonsyndromic hypodontia on craniofacial morphology

Objective:To evaluate the effects of severity and location of nonsyndromic hypodontia on craniofacial morphology.Materials and Methods:A total of 154 patients with at least two or more congenitally missing teeth were selected and divided into two groups (group I [mild]: patients with two to five missing teeth; group II [severe]: patients with six or more missing teeth). The patients with hypodontia were divided into three groups according to the location of missing teeth in the dental arches (anterior, posterior, and both anterior and posterior) and location of missing teeth between the jaws (maxilla, mandible, and both maxilla and mandible). Fifty Class I patients without any missing teeth served as the control group. Twenty-one measurements were performed on lateral cephalograms. Intergroup differences for the severity and location of hypodontia were analyzed using analysis of variance (ANOVA) and post-hoc Tukey tests.Results:Significant decreases were found in mandibular plane angles (P < .05), upper and lower incisor measurements (P < .05), anterior (P < .001) and posterior (P < .05) face heights, and ramus height (P < .01), as well as a significant increase in the soft tissue convexity angle (P < .05) among the hypodontia groups and control group. These differences were more excessive in the severe hypodontia group. Upper lip-E plane measurements were significantly longer in the mandible group than in the maxilla group (P < .01).Conclusions:Patients with congenitally missing teeth have different craniofacial morphologies. The severity and location of missing teeth have a significant effect.     

Comparison of laparoscopic common bile duct exploration and endoscopic retrograde cholangiopancreatography plus laparoscopic cholecystectomy for choledocholithiasis: a prospective randomized study

Background

Endoscopic retrograde cholangiopancreatography and laparoscopic common bile duct exploration are safe and efficient methods that have recently been used for the treatment of bile duct stones. The aim of this study was to compare the efficacy, safety, and surgical outcomes of the laparoscopic common bile duct exploration plus laparoscopic cholecystectomy (LCBDE+LC) and endoscopic retrograde cholangiopancreatography plus laparoscopic cholecystectomy (ERCP+LC).

Methods

One hundred twenty patients were prospectively randomized into 2 groups: LCBDE with LC in a single intervention and LC after ERCP.

Results

The success rate of the LCBDE+LC group (96.5%) was found to be higher than for the ERCP+LC group (94.4%). Complication rates of the LCBDE+LC and ERCP+LC group were 7% and 11.1%, respectively. Complications requiring ERCP in the postoperative period after LCBDE+LC have been noted in 3.5% of cases.

Conclusions

Laparoscopic CBD exploration provides an alternative therapeutic approach that has less morbidity, is cost-effective, and allows earlier recovery with a reduced period of short-term disability.