Iranian Endodontic Journal
Volume:3 Issue: 2, Spring 2008

Antibiotics are a valuable addition to health practitioners for the management of bacterial infections. During endodontic treatment and when managing trauma to the teeth, antibiotics may be applied systemically or locally. Due to the potential risk of adverse effects of systemic applications, and the ineffectiveness of systemic prescribed antibiotics in necrotic or pulpless teeth and the periradicular tissues, the local application of antibiotics may be a more effective mode for delivering antibiotics to infected root canals. The purpose of this article is to review the history, rationale, and applications of antibiotics and antibiotic-containing irrigants in endodontics.

This study was designed to evaluate the prevalence of referred pain with pulpal source in the head, face and neck region among patient referred to Dental school of Shahid Beheshti University MC, Tehran, Iran in 2004. In this cross-sectional study, 100 patients (55 males and 45 females) referred to oral medicine department of Shahid Beheshti Dental School evaluated via clinical and radiographic examination to seek their pain sources and sites. Inclusion criteria were report of pain and a dental clinician accomplished detection of pain origin. Exclusion criteria were non-odontogenic painful diseases, advanced periodontal disease, and substantial carious lesions. Visual analogue scale(VAS) was used to score pain intensity; meanwhile the patients were asked to mark the painful sites on an illustrated head and neck mannequin. Sixty-five percent of patients reported pain in sites which diagnostically differed from the pain source. According to statistical analysis, duration (P≤0.01), spontaneity (P≤0.001) and quality (P≤0.01) of pain influenced its referral nature, while sex and age of patients, kind of stimulus, throbbing and intensity of pain had no considerable effect on pain referral (P>0.05). The prevalence of referred pain with pulpal origin in the head, face and neck region is moderately high which requires precise diagnosis by dental practitioners. Some hallmarks of irreversible pulpitis (e.g. spontaneous and persistent pain after elimination of stimulus) are related to pain referral.

The purpose of this study was to evaluate and compare canal preparation pattern of K3 and ProTaper rotary files in curved resin blocks. Twenty-four resin blocks were used in this experimental study and randomly divided into two groups. Their initial images were scanned. After preparation, their images were scanned again in the same position. Pre and post preparation images were superimposed by Photoshop software and the removed resin was measured in 5 different points, and then analyzed statistically by ANOVA and t-tes. At O point (orifice), significantly (p≤0.05) more outer canal wall was removed in the ProTaper group than in the K3 group. There was no significant difference at any other points of outer wall. Removed material of inner canal wall was not significantly different between the two groups. Under the condition of this study, both systems performed acceptable preparation pattern except at the beginning of the curve.

The aim of this study was to compare the cytotoxicity of Mineral Trioxide Aggregate (MTA) and a New Endodontic Cement (NEC) on L929 mouse fibroblasts. Different dilutions (Neat, 1/2, 1/10, 1/100) of fresh and set materials placed adjacent flasks of L929 in DMEM medium. Cellular viability was assessed using MTT assay in three time intervals (24, 48, and 72 h after mixing). Differences in mean cell viability values between materials were assessed by using the One-way ANOVA and Bonferoni post-test. Optical microscopic analysis of morphology of the untreated control and the cementtreated cell cultures were carried out in all experimental periods. It was indicated that there was not a significant difference in cytotoxicity among the materials of test and between them and the control group. However, there was a statistically significant difference between different time intervals within each group (P≤0.05) and between different concentration of test materials (P≤0.05). In all samples, set materials showed better viability than fresh ones. According to results of this study, NEC and MTA have similar cytotoxic effect on L929 cell culture.

The preparation of the root canal space includes debridement, shaping and apical preparation. These procedures are challenging and constitute. The recent introduction of automated techniques for canal preparation has created considerable interest. The aim of this study was to test shaping ability of one hand instrumentation (passive step-back technique) and new rotary NiTi system (Mtwo instrumentation) in curved root canals. A total number of 40 curved molars selected for this in vitro study, 20 canals for each group. The mean of canal curvature in studied groups was similar.After preparation of access cavity, samples were divided into two groups. A custom made block was used for standardization of radiograph beam angel before and after preparation. In group1, samples instrumented with passive step-back technique using stainless steel K-file, Gates Glidden and Pesso reamers. Mtwo NiTi rotary file and Endo IT power driven motor were used for instrumentation of samples in group 2. Transportation of canals curvature (loss of primary curvature) after canal preparation was assessed for each sample with the aid of AutoCAD 2007 software. Stereomicroscope provided data for measurement of changes in working length after canal preparation. The mean of changes in canals curvature (canal transportation) and mean of working length changes in group 1 (passive step-back technique) were 11.77 degree and 0.202 mm (P≤0.001) and in group 2 (rotary Mtwo) were 5.58 degree and 0.202 mm (P≤0.001). According to the present results, the original canal curvature was maintained significantly better with automated Mtwo files than with hand instrumentation. These can be hypothesized that the instrumentation with Mtwo NiTi rotary file preserves the canal curvature adequately.

This study was carried out to compare the capability of K-files with Mtwo rotary file in terms of negotiation as well as depth of penetration in second mesiobuccal (MB2) canal of maxillary first molar. A total of 32 MB2 canal of maxillary first molars having different root curvatures (not more than 30 degree) and root lengths were selected and then detected by K-file #10, #8 and #6. Based upon file penetration the samples were assigned into four groups. Group A: K-file #10 penetrate>2mm into coronal third, group B: K-file #10 could penetrate2mm penetration, group C: K-files #10 and 8 could penetrate ≤0.01). Mtwo rotary files could be an efficient substitute for hand files to negotiate MB2 canal both more easily and rapidly. To our knowledge, it is the first time that a NiTi rotary file showed success in negotiation of any canal.

The aim of this study was to compare the antimicrobial effects of 2.5% Sodium hypochlorite (NaOCl), 2% Chlorhexidine Gluconate (CHX) and BioPure MTAD (MTAD) on Enterococcus (E) faecalis-contaminated root canals of human extracted teeth. Seventy human intact extracted single-rooted teeth with straight root canal randomly divided into 5 groups: positive control (n=5), negative control (n=5), 2.5% NaOCl (n=20), 2% CHX (n=20), and MTAD (n=20). Each tooth was instrumented using the passive step-back technique hand and rotary instruments. E. faecalis incubated into the canals and grew for 4 weeks. Canals irrigated using three mentioned solutions for 5 minutes. Samples were taken from canal walls and transferred into Brain Heart Infusion (BHI) culture medium and placed in an incubator at 37ºC for 96 hours and bacteriological evaluations were done. Chi- Square test and SPSS software were used for the statistical analysis of the results. Bacterial growth was seen in only one sample of MTAD group (5%), but in 4 of CHX group (20%) and 5 of NaOCl group (25%). Chi-Square test showed no statistically difference between groups. Based on the results of this study, it seems that all three solutions have acceptable antimicrobial effect on E. faecalis.

The aim of this case report was to describe the clinical management of an unusual dens invaginatus type 3. A case of dens invaginatus in a maxillary lateral incisor with a periapical lesion is reported. The patient presented with pain and localized swelling. Despite the complex anatomy and diagnosis of dens invaginatus, non-surgical root canal treatment was performed successfully.Key learning points:- Dens invaginatus may be presented in different forms, and the etiology of this phenomenon is not fully understood.- Due to abnormal anatomical configuration, dens invaginatus presents technical difficulties in its clinical management.- Non-surgical root canal treatment can be performed successfully.

In endodontics, treatment of an open apex tooth with necrotic pulp is a problem. It seems that with promotion of remnants of Hertwig''s epithelial sheath or rest of malassez accompany with a good irrigation of root canal we can expect root formation.