Investigating the Antibacterial Effect of Passive Ultrasonic Irrigation, Photodynamic Therapy and Their Combination on Root Canal Disinfection.

Introduction: Enterococcus faecalis is a gram-positive, facultative anaerobic bacterium associated with persistent endodontic infections. Conventional disinfection methods may not completely eradicate the bacteria within the root canal system. Therefore, novel modalities have been suggested to optimize root canal disinfection. The aim of this study was to evaluate and compare the antibacterial effect of photodynamic therapy (PDT), passive ultrasonic irrigation (PUI) and their combination in addition to conventional endodontic irrigation against E. faecalis biofilms in root canals. Methods: Root canals of 50 single-rooted extracted human teeth were prepared and incubated with E. faecalis for 21 days. They were then divided into 4 treatment groups and a control group as follows: (1) NaOCl-Syringe irrigation with 2.5% NaOCl, (2) PUI-Passive ultrasonic irrigation with NaOCl, (3) NaOCl+PDT-Photodynamic therapy following syringe irrigation with NaOCl, (4) PUI+PDT, (5) Control-Syringe irrigation with saline. Colony-forming units were counted and bacterial reduction was calculated for each treatment group. Results: All treatments led to significant reductions in the bacterial load compared to the control group. PUI and PUI+PDT led to the complete elimination of the bacteria from the root canals. NaOCl and NaOCl+PDT treatments reduced the bacteria by 99.9% and 99.5% respectively. NaOCl+PDT was significantly less effective in reducing the bacteria compared to other treatment groups. There were no significant differences between the NaOCl, PUI, and PUI+PDT groups. Conclusion: Passive ultrasonic irrigation with or without the combination of Photodynamic therapy completely eradicated the bacteria. The use of PDT as an adjunction to NaOCl syringe irrigation and PUI did not enhance their antibacterial effect.

Comparative Accuracy of Cone-Beam Computed Tomography and Clearing Technique in Studying Root Canal and Apical Morphology of Mandibular Canines.

Introduction: Knowledge about root canal anatomy improves the long-term prognosis of endodontic treatment. This study aimed to investigate the accuracy of cone-beam computed tomography (CBCT) in assessment of morphology of root canal and apex in mandibular canines compared with the clearing technique. Methods and Material: In this in vitro study, 33 extracted mandibular canines were subjected to CBCT with 0.1 mm voxel size. Number and type of canals, prevalence of accessory canals, anastomosis, apical delta and distance from apical constriction (AC) to apical foramen (AF) and to anatomic apex (AA) and also distance from AF to the AA were determined on CBCT scans. After access cavity preparation, a #8 K file was passed through the main apical foramen. Its direction and distance from anatomic apex was determined under a stereomicroscope. After clearing and staining of teeth, other criteria were determined with stereomicroscope under 16× magnification and served for comparison with CBCT data. The agreement of two methods were evaluated by intra-class correlation and kappa coefficients for quantitative and qualitative data, respectively. Results: Most (93.9%) canine teeth were Vertucci's type I, followed by type III configuration in both CBCT and clearing techniques. The results of both techniques were not in agreement for assessment of accessory canals, however acceptable agreement was noted between them for detection of apical delta and also assessment of apical foramen deviation in buccolingual and mesiodistal directions. Both of two techniques had excellent agreement for evaluating the distances from AF to AA, AC to AF and AC to AA. Conclusions: CBCT is a reliable tool in assessment of root canal and apical topography in mandibular canines, however its use in accessory canal detection is not recommended.

Propolis: Chemical Composition and Its Applications in Endodontics.

INTRODUCTION: The aim of this study was to review the chemical composition of propolis and its application in endodontics. METHODS AND MATERIALS: For this purpose, keywords were searched on ScienceDirect, PubMed and World of Chemicals databases in order to find published papers from 1988 to February 2018. RESULTS: There are many different compounds in propolis of different geographic regions; flavonoids are one of the most important agents which have anti-inflammatory, anti-viral, anti-allergic, anti-cancer, anti-bacterial and antioxidant effects. According to the mentioned properties, propolis can be used as a canal irrigation solution as well as intracanal medicament in endodontic treatments. Studies have shown that propolis as a storage medium is capable of maintaining the vitality of the periodontal ligaments cells and also has the ability to inhibit osteoclastic activity due to one of the active compounds present in it. In vital pulp therapy, propolis can induce the production of tubular dentin and also decrease the inflammation of the pulp. CONCLUSION: Considering the propolis components like resin, pollen, vitamins, flavonoids and phenols; it can be used for various purposes in endodontics and would have a promising role in future medicine as well as dentistry.

Comparison of the Effect of Toothbrushing Education Via Video, Lecture and Pamphlet on the Dental Plaque Index of 12-Year-Old Children.

The aim of this study was to compare the effect of different modes of toothbrushing education (lecture, video and pamphlet) on the dental plaque index (PI) of adolescents. The cluster randomized intervention was performed on 128 participants aged 12 years, who were allocated into four groups based on the type of intervention. Group 1: no intervention; and groups 2, 3, 4: education via lecture, video, and pamphlet, respectively (n = 32). Their plaque index was measured at the baseline, 24 h and two months later. Data were analyzed by repeated measures analysis of variance (ANOVA), one-way ANOVA, independent and paired t-test. The plaque indices of groups 2, 3, 4 at 24 h (p values < 0.001) and two months (p values < 0.001) showed a significant reduction when compared to the baseline. The lowest PI score was observed in the pamphlet, video and lecture groups at 24 h, respectively. After 2 months, the lowest score of PI was measured in lecture, video and pamphlet groups, respectively; however, these differences were non-significant. Therefore, toothbrushing education via lecture, video and pamphlet reduced the dental plaque index with the same effectiveness.

Histologic comparison of direct pulp capping of rat molars with MTA and different concentrations of simvastatin gel.

Previous in vitro studies have suggested that simvastatin can be used as a direct pulp capping material due to its ability to induce odontoblastic differentiation and angiogenesis. The aim of this animal study was to evaluate the pulpal response to mineral trioxide aggregate (MTA) and four concentrations of simvastatin/MTA in combination. The study was conducted in two stages using four different simvastatin concentrations and MTA as a capping material for rat maxillary molars. The grades of inflammation and continuity of dentin formation were evaluated in hematoxylin and eosin (HE)-stained samples. Dentin thickness was determined by histomorphometric analysis, and the data were subjected to statistical analysis. On day 3, mild inflammation was observed in all groups. On day 7, the simvastatin groups showed a slightly higher rate of chronic inflammation. Inflammation was not present on day 30. Discontinuous dentin was present in all methylcellulose (control) samples. Continuous dentin was formed in all of the samples treated with 1.5% simvastatin. The greatest dentin thickness was observed after treatment with 1.5% simvastatin and MTA, followed by 0.5% simvastatin. Statistical analysis demonstrated no significant differences in dentin thickness and continuity between MTA and simvastatin at 0.5% and 1.5% (P > 0.05).

Methicillin resistance and selective genetic determinants of Staphylococcus aureus isolates with bovine mastitis milk origin.

BACKGROUND AND OBJECTIVES: Staphylococcus aureus is one of the major causes of bovine mastitis, which can be transmitted from animals to humans. Methicillin-resistant S. aureus (MRSA) isolates are more attentive and if not treated promptly, they can cause death. The aim of this study was to determine the prevalence of methicillin resistance and frequency of selected virulence factors of S. aureus isolates with bovine mastitis milk origin in Ahvaz, southwest of Iran. MATERIALS AND METHODS: During a two-year period (2014-2015), 75 S. aureus isolates were recovered from referred clinical and sub-clinical bovine mastitis milk samples. The isolates were phenotypically investigated for resistance to cefoxitin by Kirby-Bauer method. DNA were analyzed by PCR for mecA and selected genes that encode the virulence factors. RESULTS: According to the results, the spa, ebpS, fnb, bbp, clfA, clfB, and cna genes were detected in 98.7, 97.3, 97.3, 86.7, 84, 84 and 65.3% of the isolates, respectively. Among the 75 isolates, only one (1.3%) isolate was methicillin-resistant. Totally, 39 isolates (50.7%) had all of these virulence factors except mecA. The results showed that 96% of the isolates had at least the fnb, ebpS and spa genes, signifying the noteworthy role of these genes in the pathogenesis of S. aureus bovine intra-mammary infection in this area. CONCLUSION: In the present study, the prevalence of mecA was relatively low, possibly indicating that cows do not play a significant role in community-acquired MRSA infection in this area. According to the results, studied virulence factors were somewhat prevalent, bearing in mind the probable risk of transmission of these isolates from cows to humans, especially those that are in close contact with infected cattle. The data presented here can be used for the introduction of a protective vaccine against this infection.

Effect of Energy Drinks on Discoloration of Silorane and Dimethacrylate-Based Composite Resins.

OBJECTIVES: This study aimed to assess the effects of two energy drinks on color change (ΔE) of two methacrylate-based and a silorane-based composite resin after one week and one month. MATERIALS AND METHODS: Thirty cubic samples were fabricated from Filtek P90, Filtek Z250 and Filtek Z350XT composite resins. All the specimens were stored in distilled water at 37°C for 24 hours. Baseline color values (L*a*b*) of each specimen were measured using a spectrophotometer according to the CIEL*a*b* color system. Ten randomly selected specimens from each composite were then immersed in the two energy drinks (Hype, Red Bull) and artificial saliva (control) for one week and one month. Color was re-assessed after each storage period and ΔE values were calculated. The data were analyzed using the Kruskal Wallis and Mann-Whitney U tests. RESULTS: Filtek Z250 composite showed the highest ΔE irrespective of the solutions at both time points. After seven days and one month, the lowest ΔE values were observed in Filtek Z350XT and Filtek P90 composites immersed in artificial saliva, respectively. The ΔE values of Filtek Z250 and Z350XT composites induced by Red Bull and Hype energy drinks were not significantly different. Discoloration of Filtek P90 was higher in Red Bull energy drink at both time points. CONCLUSIONS: Prolonged immersion time in all three solutions increased ΔE values of all composites. However, the ΔE values were within the clinically acceptable range (<3.3) at both time points.

Evaluation of the Antimicrobial Effect of Chitosan/Polyvinyl Alcohol Electrospun Nanofibers Containing Mafenide Acetate.

BACKGROUND: Chitosan, an important biodegradable and biocompatible polymer, has demonstrated wound-healing and antimicrobial properties. OBJECTIVES: This study aimed to evaluate the antimicrobial properties of mafenide acetate-loaded nanofibrous films, prepared by the electrospinning technique, using chitosan and polyvinyl alcohol (PVA). MATERIALS AND METHODS: A 3(2) full factorial design was used for formulating electrospinning solutions. The chitosan percentage in chitosan/PVA solutions (0%, 10%, and 30%) and the drug content (0%, 20%, and 40%) were chosen as independent variables. The release rate of mafenide acetate from nanofibrous films and their microbial penetration were evaluated. The antimicrobial activity of different nanofibrous film formulations against Staphylococcus aureus and Pseudomonas aeruginosa was studied. RESULTS: The results indicated that all nanofibrous films, with and without drug, can prevent bacterial penetration. Incorporation of mafenide acetate into chitosan/PVA nanofibers enhanced their antimicrobial activity against P. aeruginosa and S. aureus. CONCLUSIONS: Overall, the results showed that chitosan/polyvinyl alcohol (PVA) nanofibrous films are applicable for use as a wound dressing with protective, healing, and antimicrobial effects.

Interventions for the management of external root resorption.

BACKGROUND: External root resorption is a pathological process, which tends to occur following a wide range of mechanical or chemical stimuli such as infection, pressure, trauma or orthodontic tooth movement. Although it is predominantly detected by radiography, in some cases root resorption may be identified by clinical symptoms such as pain, swelling and mobility of the tooth. Treatment alternatives are case-dependent and aim to address the cause of the resorption and aid the regeneration of the resorptive lesion. OBJECTIVES: To evaluate the effectiveness of any interventions that can be used in the management of external root resorption in permanent teeth. SEARCH METHODS: The following electronic databases were searched: the Cochrane Oral Health Group Trials Register (to 14 October 2015), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2015, Issue 9), MEDLINE via OVID (1946 to 14 October 2015) and EMBASE via OVID (1980 to 14 October 2015). We searched the US National Institutes of Health Trials Register (http://clinicaltrials.gov) and the WHO Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We included randomised controlled trials of permanent teeth with any type of external root resorption, which has been confirmed by clinical and radiological examination, comparing one type of intervention (root canal medications and canal filling, splinting or extraction of teeth or the surgical removal of any relevant pathology) with another, or with placebo or no treatment. DATA COLLECTION AND ANALYSIS: Two review authors screened search records independently. Full papers were obtained for potentially relevant trials. If data had been extracted, the statistical guidelines set out in the Cochrane Handbook would have been followed. MAIN RESULTS: No randomised controlled trials that met the inclusion criteria were identified. However, we identified one ongoing study that is potentially relevant to this review and will be assessed when it is published. AUTHORS' CONCLUSIONS: We were unable to identify any reports of randomised controlled trials regarding the efficacy of different interventions for the management of external root resorption. In view of the lack of reliable evidence on this topic, clinicians must decide on the most appropriate means of managing this condition according to their clinical experience with regard to patient-related factors. There is a need for well designed and conducted clinical trials on this topic, which conform to the CONSORT statement (www.consort-statement.org/).

The effect of propolis as a biological storage media on periodontal ligament cell survival in an avulsed tooth: an in vitro study.

OBJECTIVE: Both the length of extra-alveolar time and type of storage media are significant factors that can affect the long-term prognosis of replanted teeth. This study aims to compare propolis 50%, propolis 10%, Hank's balanced salt solution (HBSS), milk and egg white on periodontal ligament (PDL) cell survival for different time points. MATERIALS AND METHODS: : In this in vitro experimental study, we divided 60 extracted teeth without any periodontal diseases into five experimental and two control groups that consisted each experimental group with 10 and each control group with 5 teeth. The storage times were one and three hours for each media. The controls corresponded to 0-minute (positive) and 12-hour (negative) dry time. Rinsing in the experimental media, the teeth were treated with dispase and collagenase for one hour. Cell viability was determined by using trypan blue exclusion. Statistical analysis of the data was accomplished by using two-way analysis of variance (ANOVA) complemented by the Tukey's HSD post-hoc. RESULTS: Within one hour, there was no significant difference between the two propolis groups, however these two groups had significantly more viable PDL cells compared to the other experimental media (p<0.05). The results of the three-hour group showed that propolis 10% was significantly better than egg white, whereas both propolis 10% and 50% were significantly better than milk (p<0.05). CONCLUSION: Based on PDL cell viability, propolis could be recommended as a suitable biological storage media for avulsed teeth.

Coronal sealing ability of three temporary filling materials.

INTRODUCTION: Providing adequate coronal seal of temporary filling materials is critical for the success of root canal therapy. The aim of this in vitro study was to compare coronal seal ability of three restorative materials over different periods of time. MATERIALS AND METHODS: Ninety-eight molar teeth were selected. Once access cavities were prepared, teeth were divided randomly into three time groups (1 day, 1 week, and 4 weeks). Each group was then subdivided into three groups of 10 teeth. Each subgroup was restored using one of three restorative materials including Coltosol, Cavizol and Zonalin and then incubated in distilled water at 37ºC. The samples were then immersed in 2% methylene blue dye. After rinsing and drying, teeth were sectioned longitudinally and examined for dye penetration. Kruskal-Wallis and Mann Whitney U tests were used to analyze the data. RESULTS: All experimented materials showed increasing leakage from the 1st day to the 4th week. Zonalin showed more leakage than Coltosol and Cavizol at each time interval (P<0.05), but there was no significant difference between Coltosol and Cavizol. CONCLUSION: Coltosol and Cavizol are suitable temporary materials for up to 1 week.

Effect of propolis on dentin regeneration and the potential role of dental pulp stem cell in Guinea pigs.

OBJECTIVE: Evaluation of the effect of Propolis as a bioactive material on quality of dentin and presence of dental pulp stem cells. MATERIALS AND METHODS: For conducting this experimental split-mouth study,a total of 48 maxillary and mandibular incisors of male guinea pigs were randomly divided into an experimental Propolis group and a control calcium hydroxide group. Cutting the crowns and using Propolis or calcium hydroxide to cap the pulp, all of the cavities were sealed. Sections of the teeth were obtained after sacrificing 4 guinea pigs from each group on the 10(th), 15(th) and 30(th) day. After they had been stained by hematoxylin and eosin (H&E), specimens underwent a histological evaluation under a light microscope for identification of the presence of odontoblast-like cells, pulp vitality, congestion, inflammation of the pulp and the presence of remnants of the material used. The immunohistochemistry (IHC) method using CD29 and CD146 was performed to evaluate the presence of stem cells and the results were statistically evaluated by Kruskal-Wallis, Chi Square and Fisher tests. RESULTS: In H&E stained specimens, there was no difference between the two groups in the presence of odontoblast-like cells, pulp vitality, congestion, inflammation of the pulp and the presence of remnants of used material(p>0.05). There was a significant difference between the quality of regenerative dentin on the 15(th) and 30(th) days (p<0.05): all of the Propolis cases presented tubular dentin while 14% of the calcium hydroxide cases produced porous dentin. There was no significant difference between Propolis and calcium hydroxide in stimulation of dental pulp stem cells (DPSCs). CONCLUSION: This study which is the first one that documented the stimulation of stem cells by Propolis, provides evidence that this material has advantages over calcium hydroxide as a capping agent in vital pulp therapy. In addition to producing no pulpal inflammation, infection or necrosis this material induces the production of high quality tubular dentin.

Interventions for the management of external root resorption.

BACKGROUND: External root resorption is a pathological process which tends to occur following a wide range of mechanical or chemical stimuli such as infection, pressure, trauma or orthodontic tooth movement. Although it is predominantly detected by radiography, in some cases, root resorption may be identified by clinical symptoms i.e. pain, swelling and mobility of the tooth. Treatment alternatives are case-dependant and aim at the removal of the cause and the regeneration of the resorptive lesion. OBJECTIVES: To evaluate the effectiveness of any interventions that can be used in the management of external root resorption in permanent teeth. SEARCH STRATEGY: We searched the following databases in April 2010: The Cochrane Oral Health Group's Trials Register; the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 3); MEDLINE (via OVID) (1950 to April 2010); and EMBASE (via OVID) (1980 to April 2010). We also searched two regional bibliographic databases (IndMED and Iranmedex) and handsearched five Iranian dental journals using free text terms appropriate for this review. SELECTION CRITERIA: Randomised controlled trials comparing any type of intervention including root canal medications and canal filling, splinting or extraction of teeth or the surgical removal of any relevant pathology with each other, or placebo or no treatment applied to permanent teeth with any type of external root resorption which had been confirmed by clinical and radiological examination. DATA COLLECTION AND ANALYSIS: Two review authors conducted screening of studies in duplicate and independently. The Cochrane Collaboration statistical guidelines were to be followed. MAIN RESULTS: 66 trials were identified in our searches none of which matched our inclusion criteria. However, we identified one ongoing study which is potentially relevant to this review and will be assessed when it is published. AUTHORS' CONCLUSIONS: We were unable to identify any reports of randomised controlled trials regarding the efficacy of different interventions for the management of external root resorption. In view of the lack of any high level evidence on this topic, it is suggested that clinicians decide on the most appropriate means of managing this condition according to their clinical experience with regard to patient related factors. Future research should consist of robust clinical trials which conform to the CONSORT statement (www.consort-statement.org/).

Relation between pulpal neuropeptides and dental caries.

INTRODUCTION: Dental pulp has neural fibers that produce neuropeptides like Substance P (SP) and calcitonin gene-related peptide (CGRP). The inflammation of dental pulp can lead to an increase amount of SP and CGRP release, especially in symptomatic irreversible pulpitis. Therefore, it can be assumed that neuropeptides have some role in the progression of inflammation of the dental pulp. The aim of this study was to determine the relation between the presence and concentration of neuropeptides in dental pulps of carious teeth caries. MATERIALS AND METHODS: For this purpose, pulpal tissues were collected from 40 teeth (20 carious and 20 intact). Pulpal samples were cultured for 72 hours. ELISA reader was used for the detection of SP and CGRP in supernatant fluids. Statistical analysis was made by Mann-Whitney U and Chi square tests. RESULTS: SP and CGRP were present in 65% and 20% of inflamed pulpal samples, respectively and 40% and 5% of normal pulpal samples, respectively. Level of SP was significantly higher in inflamed pulp samples compared to intact pulps; however, there was no statistical difference when the other groups and neuropeptides were compared. The mean concentration of SP in normal pulps was 3.4 times greater than that of CGRP; interestingly in inflamed pulps the concentration of SP was 22.3 times greater than CGRP. CONCLUSION: We can conclude that in inflamed dental pulps, the concentration of SP is higher than CGRP. It can be hypothesized that CGRP has less effect on the inflammatory changes of dental pulps.

Antimicrobial activity of three root canal irrigants on enterococcus faecalis: an in vitro study.

INTRODUCTION: 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. MATERIALS AND METHODS: 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. 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. CONCLUSION: Based on the results of this study, it seems that all three solutions have acceptable antimicrobial effect on E. faecalis.

Evaluation of the Sealing Ability of Amalgam, MTA, Portland Cement and Coltozol in the Repair of Furcal Perforations.

INTRODUCTION: Perforations of the pulpal floor create problems during endodontic treatment and often results in secondary periodontal involvement with eventual loss of teeth. The purpose of this study was to evaluate the ability of mineral trioxide aggregate (MTA), Amalgam, zinc oxide and eugenol (ZOE) and Portland cement to seal furcal perforations in extracted human molars using dye penetration. MATERIALS AND METHODS: This Microleakage study was conducted on 70 human permanent mandibular molars with well developed, non-fused roots. Access openings and furcation perforations were prepared in the pulp chamber floor. Ten teeth were assigned as controls and divided into two groups of five teeth each as positive and negative control. The positive group were accessed and perforated similar to experimental groups but the negative controls were not prepared. The rest of the teeth were divided in four experimental groups of 15 teeth in each group. Experimental groups comprised groups Al to A4, group Al was repaired with MTA, group A2 with Amalgam, group A3 with Coltozol (ZOE) and group A4 was repaired with Portland cement. The teeth were submerged in solution of 2% fucshin dye for 24 hours. Finally, the samples were sectioned and evaluated for linear dye leakage at X25 magnification and analyzed statistically. RESULTS: The results showed that MTA had significantly less leakage than Amalgam, Portland cement and Coltozol (P<0.05). CONCLUSION: Maximum dye penetration was observed in Coltozol followed in decreasing order by Portland cement and Amalgam.