Pain Reduction Using Low Level Laser Irradiation in Single-Visit Endodontic Treatment

INTRODUCTION: Post-endodontic treatment pain is a relatively common condition which needs analgesics for patient’s pain relief. Low-level laser therapy (LLLT) is suggested as a non-pharmacological and non-invasive treatment for dealing with painful conditions. The purpose of this study was to evaluate the pain relief effect of LLLT after endodontic treatment.METHODS: Eighty patients randomly received either LLLT (n=40), or placebo laser (n=40) after the completion of endodontic treatment for their first permanent upper or lower molars. In the laser group, the patients received a single course of low level laser therapy (Whitening Lase II- Laser DMC, Samsung, Korea) for 80 second (a dose = 70 j/cm²) per tooth. Intensity of post treatment pain was recorded using a questionnaire (The McGill Pain Questionnaire) and a numeric rating scale (Visual Analogue Scale {VAS}) at 4, 8, 12, 24, and 48 hours. VAS is a 10 cm line with “no pain” at one end, and “worst pain imaginable” at the other end. This method makes it possible to quantify pain levels. T-test and Chi-square test were used for data statistical analyses.RESULTS: Compared to the placebo group, post-endodontic pain was significantly reduced in LLLT group at 4, 8, 12, and 48 hours (P<0.05). But the difference between the two groups was not significant at 24 hours after endodontic treatment (P>0.05).CONCLUSION: Regarding the significant pain reduction in LLLT group at 4, 8, 12, and 48 hours after endodontic treatment, LLLT seems to be an effective and nonpharmacological approach for the reduction of post-endodontic treatment pain

The Antibacterial Effect of Additional Photodynamic Therapy in Failed Endodontically Treated Teeth: A Pilot Study

Introduction: Root canal therapy as a routine dental procedure has resulted in retention of millions of teeth that would otherwise be lost. Unfortunately, successful outcomes are not always achievable within initial endodontic treatments, and that necessitates further treatment. Nonsurgical retreatment is the first choice in most clinical situations. The aim of this clinical pilot study was to assess the effect of additional photodynamic therapy (PDT) on intraradicular bacterial load following retreatment of failed previously root treated teeth.Methods: Thirty single-rooted/canalled endodontically treated matured teeth (in 27 healthy patients) accompanied by apical periodontitis (AP) were selected for this study. Standard protocol was followed for nonsurgical retreatment of each tooth. Microbiological samples were taken after establishment of apical patency, finished cleaning/shaping procedure, and PDT (665 nm, 1 W, 240 seconds). All samples were cultured for 72 hours and colony-forming unit (CFU) was counted. McNemar test was used for statistical analysis of the data. The level of significance was set at 0.001.Results: Routine cleaning and shaping resulted in twenty four negative (80%) out of 30 cultures. Four additional negative results were obtained after additional PDT (93.3%). The addition of PDT to routine procedures significantly enhanced the number of bacteria-free samples (P < 0.001).Conclusion: Regarding elimination of intraradicular microbiota, additional PDT may increase the effectiveness of conventional chemomechanical preparation in previously root filled teeth accompanied by AP. Well controlled randomized clinical trials should be planned for future

Sealing Ability of Resilon and MTA as Root-end Filling Materials: A Bacterial and Dye Leakage Study

Introduction: Endodontic surgery is a valuable option for maintaining patient's natural dentition when previous orthograde endodontic treatments fail to succeed. Proper root-end preparation and placement of a retro-filling material are recommended for successful endodontic surgery. The objective of this experimental study was to compare sealing ability of Resilon/Epiphany system, as a potential root-end filling material, with ProRoot MTA using both dye and bacterial leakage models. Materials and Methods: Ninety two single-rooted extracted human teeth were decoronated and prepared endodontically. Specimens were randomly divided into four experimental groups (n=20) and four control groups (n=3). After removal of apical 3 mm and root-end cavity preparation, MTA, or Resilon were used to fill root end cavities. For bacterial leakage, specimens (20 for each experimental group, 3 negative, and 3 positive controls) were subjected to E. faecalis over a 70-day period. Methylene blue was used for dye leakage (the same in number as before). Using stereomicroscope (40× mag.) complete dye leakage was assessed after 72 h. Kaplan-Meier survival analysis was performed for bacterial leakage. The data was analyzed using t-test and Chi-square analysis (α=0.05). Results: All of the positive controls and none of negative controls revealed leakage.  Result of log rank test showed no significant difference between MTA and Resilon in time of bacterial leakage at the end of the 70 days (P>0.05) There was also no statistical difference in complete dye leakage for both groups (P>0.05). Conclusion: Leakage occurred in both MTA and Resilon as root-end filling material but the difference was not statistically significant. Resilon might be noticed as a potential root-end filling material if good isolation is attainable

Effects of Reciproc, Mtwo and ProTaper Instruments on Formation of Root Fracture

Introduction: The aim of this study was to compare the formation of dentinal crack and craze lines in the root dentin during root canal preparation with three different NiTi endodontic systems, naming Reciproc (RCP), ProTaper Universal (PTU) and Mtwo. Methods and Materials: One hundred extracted mandibular premolars with single canals were selected and decoronated. The teeth were randomly divided into four groups of 25 each (n=25). In groups 1, 2 and 3 the teeth were prepared using Mtwo, PTU and RCP, respectively. While in group 4 (control group) the samples were left unprepared. After preparation, all specimens were sectioned perpendicular to the long axis of root at 3, 5 and 9-mm distances from the apex. The sections were then individually observed under 12× magnification using stereomicroscope. The data was analyzed using the chi-square and Fisher’s exact tests. The level of significance was set at 0.05. Results: No cracks were observed in the control group. All engine-driven systems caused dentinal cracks. Mtwo and PTU caused cracks significantly more than RCP (P<0.05). There was no significant difference between RCP and control group (P>0.05). Conclusion: All three engine-driven systems created dentinal defects. Reciproc caused less cracks than Mtwo and ProTaper Universal.Keywords: Cracks; Craze Lines; Dentin; Nickel-Titanium Instruments; Root Canal Preparation; Tooth Root; Vertical Root Fractur

Subcutaneous Reaction of Rat Tissues to Nanosilver Coated Gutta-Percha

Introduction: Gutta-percha (GP), is a neutral and non-toxic material. The aim of this animal study was to compare the biocompatibility of nanosilver coated GP (NS-GP) with conventional GP in subcutaneous tissues in a rat model. Methods and Materials: Conventional GP and NS-GP were subcutaneously implanted in the backs of 20 male Wistar rats (n=10). A control animal was assigned for each trial period. Ten animals were sacrificed after 7 and 30 days and light microscopic evaluation of tissue reaction to NS-GP (n=20) and conventional GP (n=20) was accomplished. The Mann-Whitney U, Wilcoxon Signed Ranks, Fisher Exact, and McNemar tests were used for statistical analysis of the data. Results: After 7 days, inflammation was moderate and mild for NS-GP and conventional GP, respectively (P<0.001). After 30 days, no inflammation was discernible in conventional GP. However, mild inflammation was reported for NS-GP (P<0.001). Regarding inflammatory cell type, there was a significant difference between two experimental groups at both times (P<0.001). Conclusion: Inflammation decreased over time in both groups. Fibrous connective tissue, a representative of healing and control of inflammatory process, surrounded both test materials. NS-GP was biocompatible and might be a reasonable endodontic obturation material.Keywords: Gutta-Percha; Inflammation; Nanosilver Coated Gutta-Percha; Subcutaneous Connective Tissue

Sealing Ability of Resilon and MTA as Root-end Filling Materials: A Bacterial and Dye Leakage Study

Introduction: Endodontic surgery is a valuable option for maintaining patient's natural dentition when previous orthograde endodontic treatments fail to succeed. Proper root-end preparation and placement of a retro-filling material are recommended for successful endodontic surgery. The objective of this experimental study was to compare sealing ability of Resilon/Epiphany system, as a potential root-end filling material, with ProRoot MTA using both dye and bacterial leakage models. Materials and Methods: Ninety two single-rooted extracted human teeth were decoronated and prepared endodontically. Specimens were randomly divided into four experimental groups (n=20) and four control groups (n=3). After removal of apical 3 mm and root-end cavity preparation, MTA, or Resilon were used to fill root end cavities. For bacterial leakage, specimens (20 for each experimental group, 3 negative, and 3 positive controls) were subjected to E. faecalis over a 70-day period. Methylene blue was used for dye leakage (the same in number as before). Using stereomicroscope (40× mag.) complete dye leakage was assessed after 72 h. Kaplan-Meier survival analysis was performed for bacterial leakage. The data was analyzed using t-test and Chi-square analysis (α=0.05). Results: All of the positive controls and none of negative controls revealed leakage.  Result of log rank test showed no significant difference between MTA and Resilon in time of bacterial leakage at the end of the 70 days (P>0.05) There was also no statistical difference in complete dye leakage for both groups (P>0.05). Conclusion: Leakage occurred in both MTA and Resilon as root-end filling material but the difference was not statistically significant. Resilon might be noticed as a potential root-end filling material if good isolation is attainable

Endodontic Treatment of a Double-Rooted Maxillary Second Molar with Four Canals: A Case Report

A healthy female was referred to Endodontic Department. The referral letter from her dentist expressed that an emergency pulpotomy of tooth #27 had been carried out with probable perforation of the chamber floor which was due to the unusual anatomy of the chamber. Cone-beam computed tomography (CBCT) revealed that the tooth had two mesial and two distal canals. Perforation site was repaired and endodontic treatment was completed. At 24-month follow-up, patient was asymptomatic and clinical and radiographic examinations showed successful outcomes

Human Pulp Response to Direct Pulp Capping and Miniature Pulpotomy with MTA after Application of Topical Dexamethasone: A Randomized Clinical Trial

Introduction: The aim of this randomized clinical trial was to compare the histologic pulp tissue response to one-step direct pulp capping (DPC) and miniature pulpotomy (MP) with mineral trioxide aggregate (MTA) after application of dexamethasone in healthy human premolars. Methods and Materials: Forty intact premolars from 10 orthodontic patients, were randomly chosen for DPC (n=20) or MP (n=20). In 10 teeth from each group, after exposure of the buccal pulp horn, topical dexamethasone was applied over the pulp. In all teeth the exposed/miniaturely resected pulp tissue was covered with MTA and cavities were restored with glass ionomer. Teeth vitality was evaluated during the next 7, 21, 42, and 60 days. Signs and/or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. According to the orthodontic schedule, after 60 days the teeth were extracted and submitted for histological examination. The Kruskal-Wallis and Fisher’s exact tests were used for statistical analysis of the data (P=0.05). Results: Although dexamethasone specimens showed less inflammation, calcified bridge, pulpal blood vasculature, collagen fibers and granulation tissue formation were not significantly different between the groups (P>0.05). Conclusion: Topical dexamethasone did not hindered pulp healing but reduced the amount of underlying pulpal tissue inflammation after DPC and MP in healthy human premolars.Keywords: Dexamethasone; Direct Pulp Capping; Mineral Trioxide Aggregate; Miniature Pulpotomy; Vital Pulp Therap

Case Report Inferior Alveolar Nerve Paresthesia Related to Apical Periodontitis of Mandibular Third Molar

Abstract: Paresthesia of the inferior alveolar nerve (IAN) as the result of preapical inflammation or endodontic treatment is a rare but serious occurrence. The following case report describes the diagnosis and management of paresthesia related to an endodontic periodical lesion of a mandibular third molar

Evaluation of push-out bond strength of AH26 sealer using MTAD and combination of NaOCl and EDTA as final irrigation

Background: During endodontic procedures, the smear layer is formed as a result of mechanical instrumentation of the canal. Combination of ethylenediamine tetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) is widely used for removal of the smear layer. Application of Mixture of tetracycline, acid, and detergent (MTAD) as final irrigant subsequent to initial irrigation of 1.35% NaOCl has been proposed to increase clinical efficiency, biocompatibility and prolonged intra-canal antibacterial activity. Considering the importance of adhesion of endodontic sealers to the dentin walls of a prepared root canal, the present study evaluated push-out bond strength of AH26 sealer using final irrigation of MTAD and EDTA + NaOCl. Materials and Methods: Sixty five single-rooted teeth were prepared endodontically with the same chemomechanical technique and were randomly divided into three groups based on their final irrigation regimen: 17% EDTA + 5.25% NaOCl group (n = 30), MTAD group (n = 30) and control group (n = 5). Obturation of the canals was performed with gutta-percha and AH26 sealer. All teeth were sectioned in order that two specimens of 1 mm thickness were obtained from the coronal and the middle one third of each root resulting in 60 specimens for each experimental group and 10 specimens for control group. For push-out test, universal-testing machine was used to exert a constant compressive apico-coronal load at a speed of 0.5 mm/min. Minimum amount of compressive load caused dislodgement was measured and converted into megapascal (MPa) scale. One-way analysis of variance and the post hoc Tukey test were used for statistical analysis of the data (α = 0.05). Results: In MTAD group, mean micro-push-out bond strength of AH26 sealer to dentin walls was obtained 2.23 MPa compared to 2.0 MPa for EDTA + NaOCl group. The mean bond strength of AH26 sealer to dentin walls was significantly greater using MTAD compared with combination of EDTA and NaOCl or saline. Conclusion: MTAD final rinse significantly increased micro-push-out bond strength of AH26 sealer to canal dentin walls compared with EDTA + NaOCl