Iranian Endodontic Journal
Volume:5 Issue: 4, Fall 2010

The importance of the role played by bacteria in the pathogenesis of pulpal and apical disease has been established. One of the characteristics of apical periodontitis is apical bone resorption, which is due to apical immune response to bacterial infection. Recently, novel bacterial complex lipid called phosphorylated dihydroceramides has been discovered to be of inflammatory activators. The bacterial lipids stimulate prostaglandin E2, IL-6, and TNF-a secretion, inhibit osteoblast differentiation and function, and induce osteoclast formation. The biological activities are in Toll-like receptor 2 (TLR2)-dependent manner. These new findings imply that bacterial lipids could be important virulent factors that cause apical bone resorption. Future investigations may determine the significance of the bacterial lipids in the pathogenesis and treatment of endodontic diseases

Studies have shown the regulatory role of Leptin in bone formation, its expression in adipose tissue as well as increased levels in circulation following the adminstration of inflammatory stimuli such as lipopolysaccharides (LPS). However, there is little data evaluating the role of Leptin in inflammatory periapical lesions. The aim of this study was to evaluate the presence and concentration of Leptin in chronic periapical lesions. Chronic periapical lesions with different sizes were collected during periapical surgery of the mandibular molars from twenty patients and cultured for 72 hours. The ELISA method determined the concentration of Leptin in supernatant fluids of explants cultures. Statistical analysis was performed using non-parametric tests (Mann-Whitney U, Chi-Square and Spearman’s Correlation Coefficient). Leptin was found in all samples with the average concentration of 405.55±102.98 (pg/mL). There was no significant correlation between the concentration of Leptin and BMI, and the diameters of lesions. Leptin can be considered an inflammatory mediator and is likely to have a role during the early phases of dental periapical lesions. [Iranian Endodontic Journal 2010;5(4):147-50]

Sealing ability is an important factor for a root-end filling material in endodontic surgeries. This in vitro study aimed to compare the sealing ability of mineral trioxide aggregate (MTA) and a new endodontic cement named calcium enriched mixture (CEM) cement as root-end filling materials. The experiments were carried out in dry, saliva or blood contaminated root-end cavities of hundred single-rooted extracted human teeth. After decoronation, the root canals were cleaned, shaped, obturated, and stored in 100% humidity for 5 days. Removing the apical 2-3mm of each root, a 3mm deep root-end cavity was ultrasonically prepared. Samples were randomly divided into 2 test groups of 45 roots/experimental material, and one subgroup (n=15) for each environmental condition as follows; a) dried before placing the filling material, b) filled after contamination with saliva, and c) filled after contamination with blood. Ten roots were used as positive/negative controls. Samples were placed in an incubator at 37°C for a day and immersed in methylene blue dye under reduced pressure environment for 48 hours. Roots were sectioned longitudinally and examined under stereomicroscope by an independent observer. Using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction, the results demonstrated significantly less leakage for the CEM cement in saliva contaminated condition when compared to MTA

�Pulpotomy is the most common treatment in carious primary teeth with exposed pulp. Various medicaments were used in this treatment. The aim of this study was to evaluate clinical and radiographic success of Pro Root and Root� mineral trioxide aggregate. In this randomized clinical trial 70 teeth of children age 3-7 years old that met inclusion criteria were pulpotomized by Pro Root and Root MTA and all teeth were restored with amalgam. The clinical and radiographic� follow up was done at 6,12, 18, 30 months. The data was analyzed by Exact fisher test. At the end of 30 month follow up period 28 teeth in ProRoot MTA and 26 teeth in Root MTA were available for evaluation. In Root MTA 1 tooth was exfoliated and abscess was seen in 1 tooth and furca radiolucency was seen it its x-Ray. In ProRoot MTA external resorption was seen in 1 tooth. Exact fisher test did not �show any significant difference statistically in success rate between 2 groups after 30 months. Based on the results of this study success rate of Root and Pro Root mineral trioxide aggregate is similar and both of them can be used successfully in pulpotomy of primary molars.

The purpose of this study was to evaluate the efficacy of three methods in removal of Resilon/new Epiphany self-etch (SE) soft resin endodontic obturation system. Thirty extracted single rooted human teeth were prepared for endodontic treatment and obturated with Resilon/Epiphany SE. The roots were randomly divided into three groups; group 1 roots were retreated using Mtwo R/Mtwo files; group 2 were retreated using Mtwo R/Mtwo accompanied with chloroform; and group 3 were retreated using Mtwo R/Mtwo accompanied with Endosolv R. The cleanliness of canal walls was determined using scanning electron microscopy. Data were analyzed using ANOVA and LSD tests. Endosolv R combined with rotary files was more efficient in material removal compared to chloroform combined with rotary files and rotary files alone

The aims of the present study are to compare hand stainless steel K-files and Nickel titanium Profile 0.04 taper 29 series rotary instruments for their efficiency, procedure errors and time consumed in preparation of root canal system. About 46 freshly bilaterally extracted first premolars were selected. They were divided into two groups, each group with sum of 34 canals. First group teeth were prepared with k-files while the second group was prepared with profile 0.4 taper series 29 rotary files. Preparation time was recorded for both groups. Impression material were introduced to the lumen of the prepared canals and the three dimensional shape of the prepared canals were assessed under magnification of stereomicroscope to assess the efficiency in preparing canals including canal smoothness, flow and taper. showed significantly shorter preparation time for Profile than K-file. 8.8% of the canals prepared with hand K-file showed canal blockage. Change in working distance appeared in 23.5% of canals prepared with K-file and 11.7% in canals prepared with Profile. Failed instruments were significantly higher in K-files; in the form of deformation. Profiles failed instruments were in the form of fracture and no deformation detected. Both systems showed unsatisfactory walls smoothness and flow. Good taper were highly significant in K-files preparations. suggesting the use of a technique that combines the two systems in canals preparation to overcome problems associated with each system

This study compared the cleaning efficiency of Mtwo, Race and Medin nickel-titanium rotary instruments on 60 mesial roots of mandibular molars.The amount of debris and smear layer in three parts of the root canal walls was evaluated using SEM. The results for remaining debris in the coronal part of root canals were similar, whereas in the middle third, Mtwo instruments achieved significantly better results compared to Race and Medin instruments. In the apical third of the root canals more debris was found by using Race instrument. In general Mtwo instruments had greater success in producing clean canals

Persistent microorganisms in the root canal can lead to endodontic therapy failure. Overextended gutta-percha can also act as a periradicular tissue irritant. Large periapical lesions can be associated with such teeth. When using a nonsurgical approach, retrieval of overextended gutta-percha can prove to be a challenge. This case report describes the nonsurgical management of a large periapical lesion associated apical a tooth with overextended gutta-percha. Retrieval of gutta-percha was attempted but the overextended portion could not be removed. Aspiration of the purulent exudate was done through the root canal followed by use of a triple antibiotic paste. After 2 weeks the antibiotic paste was replaced with calcium hydroxide, to enhance the osseous regeneration. The periapical lesion showed a considerable amount of periapical healing at 1 year 3 months.