Sealing efficacy of mineral trioxide aggregate with and without nanosilver for root end filling: an in vitro bacterial leakage study

Various materials have been added to mineral trioxide aggregate to enhance its properties. This study was aimed to compare the sealing efficacy of MTA with and without nanosilver using bacterial leakage approach. Seventy canine teeth were prepared and obturated. Then, after apical resection, the root-end cavities were prepared by ultrasonic retrotips. Teeth were randomly divided into 4 groups containing two experimental groups (n=30) and two negative and positive controls (n=5). In group 1 and 2, root-end cavities were respectively filled with MTA and MTA with nanosilver (by 1% weight). Leakage assessment was carried out by bacterial leakage apparatus with Enterococcus faecalis species. Leakage comparison between experimental groups was done using Mann-Whitney test by Spss 16 software at significancy level of 0.05. The median bacterial leakages for MTA and MTA with nanosilver were 19 and 2, respectively. The mean bacterial leakages for MTA and MTA with nanosilver were 30.06±28.67 and 9.66±14.25, respectively. Mann-Whitney test indicated that there was a significant difference in bacterial leakage day between two experimental groups (P=0.002). Based on the findings of this in-vitro bacterial leakage study, adding nanosilver to MTA decreased its sealing ability

Evaluation of X-ray Protection Methods Used in Dental Offices in Tabriz in 2005-2006

<p><strong>Background and aims.</strong> The aim of this study was to evaluate x-ray protection methods in dental offices in Tabriz. </p><p><strong>Materials and methods.</strong> In this study 142 dental offices were evaluated. A questionnaire-based method was used. The data was analyzed by descriptive methods. </p><p><strong>Results.</strong> The least commonly used methods were leaded walls (4.9%) and film badges (16.9%) and the most commonly used methods were lead partitions (67.6%) and position-distance rule (68.3%). The most commonly used patient protection devices were E-speed films (84.5%) and long collimators (66.2%). The least commonly used methods, in this respect, were automatic processors (2.1%) and rectangular collimators (0%). </p><p><strong>Conclusion.</strong> Regarding protection methods for the patient, results did not conform to international standards. Mostly, manual processing was used, resulting in extra radiation dose to patients. The methods which reduce the received dose of patients were disregarded in offices compared to educational centers, necessitating optimization of educational programs in these fields.</p&gt

Prevalence of Fluorosis in 5-12 Year-old Children in the North-Western Villages of Makoo in 2004

<p><strong>Background and aims.</strong> Fluorosis is defined as a sort of enamel hypocalcification. Clinical features of fluorosis vary from thin white lines on the enamel to chalky and opaque enamel. The enamel may be destroyed after tooth eruption. Various prevalence rates have been reported in different populations. Major contributing factors are temperature, altitude and hygienic trends. The aim of this study was to evaluate the prevalence and severity of fluorosis in 5-12 year-old children in the North-Western villages of Makoo. </p><p><strong>Materials and methods.</strong> A total of 58 children aged between 5 and 6, and 421 students aged between 7 and 12 from the North-Western villages of Makoo were selected. Dean Index was used to evaluate the prevalence of fluorosis in the primary and permanent dentition. To compare the severity of fluorosis in the maxilla and mandible and also to assess the coordination rate of fluorosis in the left and right sides of the jaw, TF Index was used. TSIF was used to compare fluorosis rate in different tooth surfaces. Discoloration prevalence and rate were compared between maxillary and mandibular incisors. Chi-square test and t-test were used to analyze the results. </p><p><strong>Results.</strong> Fluorosis rate in the primary and permanent dentition was 100%. According to TF Index, the highest coordination rate was observed in mandibular incisors and the least was observed in maxillary second molars. The difference in the severity of fluorosis between maxilla and mandible was statistically significant (p< 0.05). Discoloration rate increased in maxillary central incisors with age. </p><p><strong>Conclusion.</strong> Very high prevalence rate of fluorosis in the primary and permanent teeth in the North-West of Makoo revealed a major regional problem; therefore, preventive strategies such as informing people of improper use of fluoride-containing supplements and reduction of the fluoride content of drinking water are suggested.</p&gt

Influence of the Display Monitor on Observer Performance in Detection of Dental Caries

<p><strong>Background and aims.</strong> Digital imaging continues to gain acceptance in dentistry and video display used for this becomes important. The aim of this study was to assess the influence of the display monitor on observer performance on caries detection. </p><p><strong>Materials and methods.</strong> Artificial enamel lesions were created in 40 extracted teeth at random using 1/4 and 1/2 round burs. Teeth were mounted in dental stone blocks to simulate a hemi-dentition. Approximate exposures were recorded at 70 kVp using a Planmeca (Planmeca Co, Helsinki, Finland) digital imaging system. Three oral and maxillofacial radiologists rated each image on a five-point scale for the presence or absence of lesion. Radiographic images were viewed on the following monitors: (1) LG Flatron 700p (LG Electronics Co., South Korea); (2) Samsung Magicgreen (Samsung Electronics Corp., South Korea); (3) Hansol 710p (Hansol Electronics Corp., South Korea) and (4) Toshiba satellite laptop (Toshiba Computer Corp., Philippines). Examiners were allowed to magnify and adjust density and contrast of each image at will. Receiver Operating Characteristic (ROC) analysis was performed. Data was subjected to repeated measures analysis of variance and ordinal logistic regression to test for significance between variables and to determine odds ratios. </p><p><strong>Results.</strong> Mean ROC curve areas ranged from 0.8728 for the LG monitor to 0.8395 for the Samsung. Repeated measures analysis of variance showed significant differences between observers (P< 0.0001), lesion size (P< 0.0001), examiner/monitor interaction (P< 0.033) and examiner/block interaction (P< 0.013). However, no significant difference was found between monitors. </p><p><strong>Conclusion.</strong> This study suggests that observer performance is independent of the visual characteristics of the display monitor.</p&gt

Evaluation of Genetic Pattern of Gentamicin-resistant Enterococci Isolated from Clinical Samples

Background and aims. Enterococci are among resistant microorganisms to antibiotics and are responsible for some of acute gingival infections. This study aimed at molecular evaluation of gentamicin-resistant enterococcus species and determining the resistance genes. Materials and methods. Clinical samples were cultured on BHI medium and enterococci were isolated by specific methods and antibiograms were prepared. DNA was derived from gentamicin-resistant species by alkaline lysis method and replicated by PCR method. Four gentamicin-resistant genes were evaluated by electrophoresis method on agarose gel. Results. From 105 Enterococcus faecalis isolates, 36.2% and from 38 Enterococcus faecium isolates, 78.2% were resistant to gentamicin. 60% of these species bore aac (6’)- le – aph(2”)- la gene. ph(2”)- Ib,Ic,Id genes were not seen in any of the evaluated species. Conclusion. In gentamicin-resistant species of E. faecalis and E. faecium, the aac (6’)- le – aph(2”)- la gene was identified as the main cause of resistance

Microbial flora of root canals of pulpally-infected teeth: Enterococcus faecalis a prevalent species

Background and aims. The aim of this study was to determine the microorganisms prevalent in the necrotic dental pulp and root canals of unsuccessfully treated teeth. 
 Materials and methods. The present study was conducted on 150 single-rooted teeth of patients referring to a dental clinic. Sampling was performed by placing a sterile paper point in the canal for 60 s. Bacterial samples were evaluated by a microbiological technique specific for anaerobic species, used for isolation and identification of sampled strains. 
 Results. From the 150 samples taken, 101 were from necrotic pulps (primary infection) and 49 were from the teeth with an unsuccessful endodontic treatment (secondary infection).
 Conclusion. Enterococcus faecalis was a prevalent species in the failed root canals evaluated

Antibiotic Resistance in Enterococcus faecalis Isolated from Hospitalized Patients

Background and aims. Enterococci are Gram-positive cocci that often occur in pairs (diplococci) or short chains. Beside developing high level of antibiotic resistance, these bacteria can cause wide range of disease in human, thus to help provide an effective treatment for infections caused by this genus, this study was conceived to provide information on Enterococcus faecalis Antibiotic resistance to widely used antibiotics in hospitalized patients. Materials and methods. Disk diffusion agar and Broth dilution methods were used to perform Antibiogram test on isolated Enterococcus faecalis. Culture medium used for Disk diffusion agar test was Muller Hinton agar, and for Broth dilution methods, Muller Hinton broth culture medium was utilized. In disk diffusion agar method, different commercial antibiotics disks produced by Pharmaceutical companies were used. Microsoft Excel software was used to perform statistical analysis. Results. Based on antibiograms of 105 cases, a high resistance to Synercid, Nalidixic acid, Oxacillin and Teofilin was detected whereas the lowest resistance observed in Nitrofurantoin, Vancomycin, Linezolid and Teicoplanin antibiotics. Conclusion. According to the results, Teicoplanin, Vancomycin, Linezolid and Nitrofurantoin are recommended against E. faecalis specie

Antibacterial Effect of Diclofenac Sodium on Enterococcus faecalis

Objective: Non-steroidal anti-inflammatory drugs (NSAIDs) have shown antibacterial activity in some recent studies. The aim of this study was to evaluate the antibacterial effect of diclofenac against Enterococcus faecalis (E. faecalis) as a resistant endodontic bacterium in comparison with ibuprofen, calcium hydroxide and amoxicillin.Materials and Methods: The antibacterial activity of materials was evaluated using agar diffusion test and tube dilution method. Mixtures of 400 mg/ml of materials were prepared. The bacteria were seeded on 10 Muller-Hinton agar culture plates. Thirty microliter of each test material was placed in each well punched in agar plates. After incubation, the zone of bacterial inhibition was measured. Minimum inhibitory concentration (MIC) of the test materials was determined by agar dilution method. One-way Analysis of Variance (ANOVA) followed by Sidak post hoc test was used to compare the mean zone of microbial growth in the groups.Results: There were significant differences between the two groups (p< 0.05). Results of the agar diffusion test showed that antibiotics (amoxicillin, gentamycin) had the greatest antibacterial activity followed by NSAIDs (ibuprofen, diclofenac). Ca(OH)2 failed to show antibacterial activity. Diclofenac and ibuprofen showed distinct antibacterial activity against E. faecalis in 50 µg/ml and above concentrations.Conclusion: Within the limitations of this in vitro study, it is concluded that diclofenac and ibuprofen have significantly more pronounced antibacterial activity against E. faecalis in comparison with Ca(OH)2