Effects of a Peganum harmala (Zygophyllaceae) preparation for root canal disinfection.

The aim of this study was to determine the antimicrobial capacity, minimum inhibitory concentration (MIC), and cytotoxic effects of a Peganum harmala seed extract in comparison to 5.25% sodium hypochlorite (NaOCl). The oral pathogen Enterococcus faecalis was used to evaluate the antimicrobial capacity, and the MIC values were determined through serial dilution. Inhibition zones were measured in millimeter, and the data were analyzed statistically by analysis of variance and the Tukey HSD test. For cytotoxicity testing, P. harmala seed extract and 5.25% NaOCl solution were incubated with L929 fibroblast cells. After 1, 24, and 72 hr of incubation, cells were stained and the optical density determined with an enzyme-linked immunosorbent assay (ELISA) reader. Data were analyzed with Chi-Square statistical test. The significance level was set at p < .05. There was no significant difference between the antimicrobial capacity of 5.25% NaOCl and the P. harmala extract (p > .05; MIC 4 µg/ml). The Microculture Tetrazolium (MTT) assay test showed that the cytotoxic effects of the P. harmala extract were significantly lower than 5.25% NaOCl (p < .05). The results show that 5.25% NaOCl and P. harmala seed extract have similar antimicrobial activity against Enterococcus faecalis; but P. harmala, which shows reduced cytotoxicity, should be considered for further investigation as a safe, phytotherapeutic, intracanal irrigant.

The Effect of Fragaria vesca Extract on Smear Layer Removal: A Scanning Electron Microscopic Evaluation.

INTRODUCTION: Successful endodontic treatment depends on elimination of the microorganisms through chemomechanical debridement. The aim of this in vitro study was to evaluate the effectiveness of Fragaria vesca (wild strawberry) extract (FVE) on the removal of smear layer (SL). METHODS AND MATERIALS: In this analytical-observational study, 40 extracted mandibular and maxillary human teeth were selected. After canal preparation with standard step-back technique, the teeth were randomly divided into 4 groups according to the irrigation solution: saline (negative control), 5.25% NaOCl+EDTA (positive control), FVE and FVE+EDTA. The teeth were split longitudinally so that scanning electron microscopy (SEM) photomicrographs could be taken to evaluate the amount of remnant SL in coronal, middle and apical thirds. The data were analyzed statistically by the Kruskal-Wallis and Mann Whitney U tests and the level of significance was set at 0.05. RESULTS: Significant differences were found among the groups (P<0.001). The use of NaOCl+EDTA was the most effective regimen for removing the SL followed by FVE+EDTA. FVE alone was significantly more effective than saline (P<0.001). CONCLUSION: FVE with and without EDTA could effectively remove the smear layer; however, compared to NaOCl group it was less effective.

Microhardness Properties of Mineral Trioxide Aggregate and Calcium-enriched Mixture Cement Plugs at Different Setting Conditions.

BACKGROUND: Providing an apical stop in open apex roots is one of the endodontic challenges. The aim of present study was to compare the surface hardness of both mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement at different setting situations. MATERIALS AND METHODS: A total of 40 freshly extracted human teeth with a single root and normal apex and no obvious caries or curvatures were selected. The teeth were sectioned horizontally from the cement enamel junction and 2 mm above the apex. Standard technique was administered for cleaning and shaping of the canals. Open apex root canal was prepared by using Peso reamer. The prepared teeth were randomly divided into four groups in which two groups were filled by MTA and the other groups were filled by CEM. White MTA and CEM cement plugs were prepared and condensed up to the apical end. In two groups, moistened paper point was placed in the canals and in the other group dried paper points was used. Vickers test was done to evaluate the microhardness and the collected data were analyzed by Kruskal-Wallis and three-way ANOVA tests using SPSS software version 18 at a significant level of 0.05. RESULTS: The highest and lowest surface hardness was observed in CEM group at dried condition with 4 mm thickness indentation (145.10 ± 7.60 kg/mm(2)) and moist MTA group indented at 8 mm thickness (111.25 ± 5.37 kg/mm(2)). However, no significant difference was noticed (P > 0.05). CONCLUSION: Humidity condition might not influence the microhardness properties of both MTA and CEM cement apical plugs at different tested indentation thickness.

The Effect of Preparation Size on Efficacy of Smear Layer Removal; A Scanning Electron Microscopic Study.

INTRODUCTION: Enlargement of the root canal may potentially affect efficient smear layer (SL) removal. The aim of the present in vitro study was to compare SL removal following canal preparation with two different sizes/tapers by means of scanning electron microscopy (SEM). METHODS AND MATERIALS: A total of 50 extracted human mandibular premolars were decoronated. The teeth were randomly divided into two experimental groups (n=20) and two negative control groups. In groups 1 and 2 the sizes of master apical file (MAF) were #25 and 40, respectively. Coronal part of the canals were flared with #2 Piezo drills in group 1 and sizes #2 to 6 in group 2. Finally FlexMaster NiTi rotary instruments were used to complete canal preparation (25/0.04 and 35/0.06 in groups 1 and 2, respectively). The irrigation protocol consisted of 10 mL of 17% ethylenediaminetetraacetic acid (EDTA) for 1 min followed by 10 mL of 5.25% NaOCl for 3 min. The patency of dentinal tubules was evaluated under SEM with Hülsmann scores. Data were analyzed with the Kruskal-Wallis and Mann-Whitney U tests. RESULTS: The number of patent dentinal tubules in coronal third of the group 1 was significantly more than group 2 (P<0.001). However, this difference was not significant for the middle and apical segments. There was a significant difference in the number of patent dentinal tubules between coronal, middle and apical thirds (P<0.05). CONCLUSION: Increasing the canal preparation size did not lead to better cleanliness of the canal walls and more efficient smear layer removal.

Diagnostic value of cone-beam computed tomography and periapical radiography in detection of vertical root fracture.

INTRODUCTION: Vertical root fracture (VRF) is the longitudinal fracture of the root in endodontically treated teeth. Considering the limitations of two-dimensional radiographic images in detection of VRF and introduction of cone-beam computed tomography (CBCT), this study was designed to find the sensitivity, specificity and accuracy of CBCT and periapical (PA) radiography in detection of VRFs. METHODS AND MATERIALS: This was a cross-sectional in vitro study on 80 extracted human single canal teeth including 40 maxillary and 40 mandibular teeth. After standardized endodontic treatment of the roots, VRF was induced in half of the teeth in each group, and other half were left without fracture. Teeth were inserted in dry maxillary and mandibular alveoli. PA radiographs and CBCT images were taken from the specimens. Data were analyzed with SPSS software. The McNemar test was used to evaluate the sensitivity, specificity and accuracy of images, and kappa coefficient was used to assess the degree of agreement between the observers. The level of significance was set at 0.05. RESULTS: Sensitivity and specificity values of CBCT were 97.5% and 95%, respectively. However, for PA radiography the sensitivity and specificity were 67.5% and 92.5%, in order of appearance. Accuracy of CBCT (96.25%) and PA radiography (80%) in both jaws were significantly different (P=0.022). Two methods were not significantly different when testing specificity (P=0.298). CONCLUSION: This study showed that the sensitivity and accuracy of CBCT in detection of vertical root fracture are higher than periapical radiography. CBCT can be recommended to be used in detection of vertical root fractures.

Impact of root canal preparation size and taper on coronal-apical micro-leakage using glucose penetration method.

OBJECTIVES: The purpose of this in vitro study was to assess the effect of root canal preparation size and taper on the amounts of glucose penetration. MATERIAL AND METHODS: For conducting this experimental study, eighty mandibular premolars with single straight canals were divided randomly into 2 experimental groups of 30 samples each and 2 control groups. Using K-files and the balance force technique, canals in group 1 were prepared apically to size 25 and coronally to size 2 Peesoreamer. Group 2 were instrumented apically and coronally to size 40 and size 6 Peesoreamer, respectively. Rotary instrumentation was accomplished in group 1; using size 25 and .04 tapered and in group 2, size 35 and .06 tapered Flex Master files. Canals were then obturated by lateral compaction of cold gutta-percha. Glucose penetration through root canal fillings was measured at 1, 8, 15, 22 and 30 days. Data were recorded as mmol/L and statistically analyzed with Mann-Whitney U test (P value=. 05). RESULTS: In comparison to group 1, group 2 showed significant glucose leakage during the experimental period (P value < .0001). Also, in each experimental group, the amount of micro-leakage was significantly increased at the end of the study. CONCLUSIONS: Under the condition of this study, the amounts of micro-leakage through root canal fillings are directly related to the size and taper of root canal preparation and reducing the preparation size may lead to less micro-leakage. Key words:Dental leakage, root canal preparation, endodontics.

The effect of retreatment procedure on the pH changes at the surface of root dentin using two different calcium hydroxide pastes.

AIM: To compare pH changes at the cervical, middle and apical surfaces of root dentin in retreated and non- retreated teeth, after canal obturation with two different calcium hydroxide pastes. MATERIALS AND METHODS: After instrumentation of 55 extracted teeth, three cavities with 0.75 mm depth and 1.5 mm in diameter were drilled at buccal root surface. The teeth were randomly divided into five groups. Canals in the first two groups were filled with either mixture of calcium hydroxide and saline solution and calcium hydroxide and 2% chlorhexidine (CHX). In the third and fourth groups canals were first obturated with gutta-percha and AH26 sealer, and then materials were removed. After 2 days canals were filled with two different calcium hydroxide pastes similar to the first and the second groups. The pH was measured in the prepared cavities at 1, 3, 7 and 14 days. RESULTS: In the non-retreated groups, pH at the surface of the roots was significantly higher in comparison to the retreated ones (P value < 0.001). pH values were significantly higher in the non-retreated teeth filling with calcium hydroxide and saline solution (P value < 0.001). CONCLUSION: Regarding to the little pH changes at the surface of dentin in retreated teeth, the hydroxyl ions cannot penetrate into the dentinal tubules. Thus, to achieve higher pH at the root surface in retreated teeth, it is clinically advisable to remove more dentin from the inner walls and to use normal saline as a vehicle for calcium hydroxide rather than acidic pH materials.

Knowledge of Oral Hygiene among Hemophilic Patients Referred to Iranian Hemophilia Society.

BACKGROUND AND AIMS: Hemophilic patients are faced with poor oral hygiene due to concerns about their dental care. The present study assessed the knowledge of hemophilic patients about oral hygiene and the effect of oral hygiene instruction in patients referred to Iranian Hemophilia Society. MATERIALS AND METHODS: This cross-sectional study was carried out on 30 hemophilic patients randomly selected from volunteer patients referred to Iran Hemophilia Center. The study was performed by means of a questionnaire submitted to subjects before and after the instructional brochure submission. The questionnaire included demographic data and items regarding hemophilia and oral hygiene. Data was analyzed with McNemar test and paired t-test. RESULTS: The mean age of the patients was 21 years; 27 (90%) were males and 3 ones (10%) were females. They were mostly A hemophilia infected. Most patients enjoyed fair knowledge of oral hygiene. Changes in knowledge after reading the bro-chure were significant regarding the appropriate time to replace the toothbrush (P < 0.01), necessary visits for tooth examina-tions (P < 0.04), adjunctive methods of caries prevention (P < 0.001) and factors related to bleeding (P < 0.01); other factors improved slightly without significant changes. CONCLUSION: The knowledge of hemophilic patients was fair regarding oral hygiene while some relevant factors improved after instructions. However, more instruction is needed in order to attain more improvement in some behaviors.

One-visit versus multiple-visit endodontic therapy--a review.

A growing perception in endodontic circles is that root canal therapy requires one treatment visit only. One-visit endodontics offers many potential advantages. It is less time-consuming, resulting in less cost for the patient, potentially more profit for the dentist, less painful and less traumatic than multi-visit treatment. Conversely, if the pulp is necrotic and/or associated with periradicular disease, the root canal system is infected. In these cases, the root canal system should ideally be cleaned, an intracanal medication placed, and the canal filled at a second visit. In this paper we aim to review several aspects of one-visit versus multi-visit endodontic treatment and future perspectives in this field.

In vitro evaluation of antibacterial activities of root canal sealers.

OBJECTIVE: The purpose of this study was to compare the antimicrobial effect of AH-26 (a resin-based sealer), Dorifill (a ZOE-based sealer), and pure ZOE after 24 hours and after one week. METHODOLOGY: All sealers were prepared according to the manufacturers' directions immediately before testing. The micro-organisms used in this assay included Staphylococcus aureous and Streptococcus mutans, which were prepared from isolated species in the microbiology laboratory. The antimicrobial effects of each sealer were determined by measuring the diameter of the zone of inhibition in millimeters after incubation at 37 degrees C for 24 hours and seven days in a humid atmosphere. Each test was repeated three times. RESULTS: In the 24-hour samples, the antibacterial activity of AH-26 was significantly greater than two other materials tested on both bacteria (p < 0.05). The antibacterial activity of Dorifill and ZOE on S. aureous was not significantly different from each other (p > 0.05), but Dorifill had a significantly greater effect on S. mutans than ZOE (p < 0.05). In the seven-day samples, statistically significant zones of bacterial growth inhibition for both bacterial species tested were observed in descending order of antibacterial activity as ZOE > AH-26 > Dorifill (p < 0.05). CONCLUSION: The products studied exhibited some variable antibacterial properties. In 24 hours, the AH-26 exerted the greatest activity against both organisms tested. By seven days, the ZOE-based sealer-Dorifill-showed lower antibacterial activity than AH-26 and pure ZOE.