Journal of Mashhad Dental School
Year:2016 | Volume:40 | Issue:2|Papers Count:13

Introduction: Increased resistance of oral pathogens to conventional antimicrobial agents has led to the use of alternative methods to overcome microbial resistance. The purpose of this in vitro study was to evaluate the effect of antimicrobial photodynamic therapy on Streptococcus mutans.Materials & Methods: In this in vitro study, a diode laser emitting a wavelength of 810nm was used in association with EmunDo as a photosensitizing agent. Suspensions of Streptococcus mutans were prepared and divided into six groups by treatment: 1) EmunDo, 2) diode laser irradiation (100mW, 90 seconds), 3) diode laser irradiation (300mW, 30 seconds); 4) EmunDo+diode laser irradiation (100mW, 90seconds), 5) EmunDo+diode laser irradiation (300mW, 30 seconds), 6) control (no treatment). Immediately and 24 hours after photodynamic therapy, the bacterial suspensions were cultured. After incubation at 37°C, viable microorganisms of Streptococcus mutans were counted and the results were reported in colony-forming units (CFU). Data were analyzed by repeated measures analysis of variance at significance level of 0.05.Results: According to the repeated measures analysis, no significant between-group differences were found in the number of Streptococcus mutans colonies, either immediately or 24 hours after photodynamic therapy (P>0.05). The number of Streptococcus mutans colonies increased significantly at 24 hours after photodynamic therapy compared to immediately after treatment in all groups (P<0.001).Conclusion: Under the conditions used in this study, photodynamic therapy had no effect on viability of Streptococcus mutans. However, more evidence-based data are required regarding different photosensitizing agents and laser parameters for a definite conclusion.

Introduction: Basic Science Examination is the exam for dental students that should have sufficient predictive validity for screening students. The aim of this study was to determine the relationship between basic science examination scores and students, clinical competence as the main expected role for dentists in health system.Materials & Methods: Dentistry Students who had entered Mashhad Dental School in years 2007 to 2009 and participated in basic science examination in years 2009 to 2011 were selected. The students’ basic science examination scores and their average in first and second semester of the fifth year in dental school were extracted from their records. The relationship between the score and the average was investigated by SPSS version 11.5 software.Results: The calculation of correlation coefficients between the students’ basic science examination scores and their average in second semester of the fifth year and total average of fifth year in dental school (P<0.001) represented a significant correlation. Also the calculation of correlation coefficients between students’ basic science examination scores and their average in first semester of the fifth year in dental school for the Incoming students in 2001 & 2009 (P<0.001) and Incoming students in 2008 (P=0.003) represented a significant correlation. There was a significant correlation coefficient between each student’s basic science examination score and their average in first semester of fifth year (P<0.001) and second semester of the fifth year (P=0.005) and total average of fifth year (P=0.002) in dental school for all male students. Also there was a significant correlation coefficient between the student’s basic science examination score and their average in first semester of fifth year (P<0.001) and second semester of the fifth year (P<0.001) and total average of fifth year (P<0.001) in dental school for all female students.Conclusion: The results showed that despite the structural dissimilarity of basic sciences and clinical subjects, basic science examination can be a valid instrument for screening students for the next academic courses and identification of students.

Introduction: Periodontitis is an inflammatory disease which affects vascular supporting tissues of teeth. Angiogenesis is an integral component in the pathogenesis of vascular diseases and chronic inflammations, such as periodontitis. On the other hand, one of the major regulators of new vessels formation is vascular endothelial growth factor (VEGF). The aim of this study was to determine and compare VEGF levels in gingival crevicular fluids (GCF) among patients with aggressive and chronic periodontitis and healthy individuals.Materials & Methods: In this cross-sectional clinical study, forty-five volunteers were divided into three equal groups consisting of healthy individuals, chronic periodontitis and aggressive periodontitis. In order to perform sampling, GCF was absorbed by putting number 40 endodontic paper cones in the the gingival sulci with highest degrees of clinical attachment loss and inflammation signs. Similarly, mesiobuccal sulci of left maxillary first molars were sampled in healthy individuals. After collecting all samples, VEGF levels were determined using ELISA method.Results: The present study showed that VEGF concentration means in healthy individuals, chronic periodontitis and aggressive periodontitis were respectively 192.63±170.07, 1409.38±244.12 and 1734.33±317.13 nanograms per liter. VEGF levels in patients with aggressive periodontitis were significantly higher than chronic periodontitis (P=0.003) and VEGF levels in patients with both types of periodontitis were significantly higher than healthy individuals (P<0.001). However, there was no significant correlation between VEGF levels and age or sex of patients (P>0.05).Conclusion: VEGF levels were significantly higher in both types of periodontitis than healthy individuals and were significantly higher in aggressive periodontitis than chronic periodontitis.

Introduction: Viewing to the increased incidence of candidiasis, the bitter taste of nystatin, and the need for its repeated administration, the role of medicinal plants as well as global trends in herbal medicine, the present study was performed to compare the inhibitory effect of Thymus eriocalyx and Thymus kotschyanus with nystatin on the growth of Candida albicans.Materials & Methods: In this in vitro study the minimum inhibitory and fungicidal concentration of essential oils of Thymus epicalyx and Thymus kotschyanus on the growth of Candida albicansans was determined and then the diameter of growth inhibition of the two plants adjacent minimum inhibitory and fungicidal concentration were compared with inhibition zone of nystatin. Data was analysed by SPSS using one-way ANOVA at the significance level of 0.05.Results: In this study the minimum inhibitory concentration of plant Thymus eriocalyx and Thymus kotschyanus was 4.2 ml/ml and 3.3 ml/ml respectively and minimum fungicidal concentrations of these two plants, was 4.2 ml/ ml and 4 ml/ ml, respectively. The diameter of growth inhibition zone of Thymus eriocalyx in MIC and MFC was 19.5 mm and 18.95 mm; respectively. These diameters were 18.4 mm and 21.05 mm for Thymus kotschyanus in MIC and MFC; respectively. The results of statistical analysis showed no significant difference between the diameter of growth inhibition zone of essential oils and nystatin (P>0.05).Conclusion: Based on the results of present study, the essential oil of Thymus eriocalyx and Thymus kotschyanus have appropriate inhibitory effects on the growth of the Candida albicans. The inhibitory effect of these essential oils is comparable with nystatin.

Introduction: Oral lichen planus is considered as on oral premalignant lesion. Moreover, cell surface glycoconjugates such as sialic acid play an important role during malignant transformation of cells. In this study, salivary total sialic acid level was compared in patients with oral erosive lichen planus and healthy persons.Materials & Methods: Unstimulated saliva samples of 60 subjects (30 patients with oral lichen planus and 30 healthy) individuals who referred to the oral medicine department of dental school of Zahedan were collected. The level of salivary total sialic acid was measured by standard biochemical methods and the obtained data were analyzed by statistical spss-20 through t-test.Results: The mean level of salivary total sialic acid was 85.63±48.89 mg/ml in patient group and 60.02±26.45 in control group. The difference was statistically significant (P=0.002).Conclusion: The level of salivary total sialic acid was higher in patients with oral erosive lichen planus compared to the healthy group.

Introduction: Oral infections induced by Candida species are widely increasing in frequency. One of the most common local treatments for candidiasis is miconazole which has antibacterial effect in addition to antifungal effect. Common antifungal treatments have several side effects and cause drug resistance and high recurrences rate. Thus finding a suitable solution as an alternative synthetic drugs seems logical. The aim of this study was to evaluate antifungal effect of Achillea mille folium extract on Candida Albicans growth in comparison with Miconazole.Materials & Methods: For this laboratory study, aqueous and alcoholic extract of Achillea millefolium were produced by the method of Percolation, and six concentrations (10, 20, 30, 40, 70 and 100%) of each extract were prepared. Condida albicans was then cultured and on each plate, one plant extracts disc, one Miconazole disc, one Nystatin disc as positive control and one distilled water disc as negative controls were placed. After 48 hours, the mean diameter of non-growth halo of extract concentrations was compared with Miconazole discs by one-way ANOVA, t-student and Mann-whitney test (a=0.05).Results: The mean diameter of non-growth halo around the discs containing aqueous and alcoholic Achillea mille folium extract in all concentrations was less than Miconazole with a significant difference (P˂0.001).Conclusion: The extracts of A. mille folium plant had no significant antifungal effect on Candida Albicans growth in comparison with Miconazole.

Introduction: Accurate estimation of the amount of blood loss for predicting the need for transfusion during bimaxillary orthognathic surgery is important for maxillofacial surgeons and anesthesiologists. The aim of this study was to determine the amount of blood loss during various types of orthognathic surgery.Materials & Methods: A total of 92 patients were selected and were separated into two groups of monomaxillary & bimaxillary. All the surgeries were performed in Ghaem Hospital of Mashhad University of Medical Sciences under anesthesia with deliberate hypotension. Blood pressure during surgery was maintained under 100 mm/hg. Surgical blood losses was measured by the amount of blood in the surgical suction unit and counting the number of gauze pads saturated with blood by the anesthesiologiste and at the end of surgery was recorded. In the end, the amount of blood loss was determined separately according to the type of surgery & was statistically analyzed.Results: The study sample consisted of 92 subjects with a mean age of 23.6±3.64 years and all of the subjects completed the study. The average surgical blood loss was 351.63 ml. Mann-Whitney Test showed that the amount of blood loss in class II was significantly higher than class III (monomaxillary P=0.040 and bimaxillary P=0.008). Blood loss in monoaxillary surgery was significiently less than bimaxillary surgery (P<0.001).Conclusion: According to the present study, the amount of bleeding among different types of orthognathic surgeries is different depending on type & number of surgery and these factors are important in estimating the amount of blood loss and peredicting the necessary actions in order to replace the lost blood volume.

Introduction: Clinically, dental plaque is a white or grayish-yellow matter and a flexible concrete with known structure. It plays a crucial role in periodontal disease. Propolis is a natural bee product which has anti-bacterial properties and has been hypothesized as a good material for removal of bacterial plaque and inhibition of gingival inflammation. The aim of this study was to evaluate the effect of propolis on dental plaque and gingival inflammation.Materials & Methods: This cross over clinical trial study was conducted on 20 dental students. After examination, all cases received the designated toothpastes either with or without propolis for two weeks. The plaque and gingival indices were examined at baseline and after two weeks of using both types of toothpastes. Independent t test and paired t test was used to analyze the data using SPSS package.Results: The results indicated that after two weeks there was no significant difference in the PI, but the GI between the two groups was different.Conclusions: Propolis had no significant effect on the accumulation of bacterial plaque, but in can be used as a good compound to reduce gingival inflammation.

Introduction: Bacteria and their products have an important role in root treatment failure and their continued presence in seemingly well-filled canals, cause disturbances in healing process after the treatment. Thus the use of proper disinfectants for mechanical cleaning of canals has a great importance. Nowadays, scientists are seeking better alternatives with greater efficiency and less toxic effect for common chemical disinfectants. Therefore, the aim of this study was to evaluate the antimicrobial effects of Matrica and Chlorhexidine compared to Sodium hypochlorite on Enterococcus faecalis and Candida albicans in the laboratory conditions.Materials & Methods: In this in vitro study, Candida albicans and Enterococcus faecalis microorganisms were cultured with Kirby Bauer method on Mueller Hinton agar medium. Then paper disks impregnated with Matrica (pure and 50%), chlorhexidine (0.2% and 0.1%) and sodium hypochlorite 1% were placed on the medium. Forty-eight hours later, the zone of growth inhibition was measured in terms of millimeters. Data were analyzed by SPSS-18 software using ANOVA and TUKEY statistical tests.Results: According to the findings of this study, the highest mean diameter of inhibition zone of bacteria Enterococcus faecalis and Candida albicans, was for sodium hypochlorite 1% followed by chlorhexidine 0.2%, chlorhexidine 0.1%, pure Matrica and Matrica 50%, respectively (P<0.000).Conclusion: Considering the results of this study, it seems that the antimicrobial effect of herbal composition of Matrica is not as efficient as sodium hypochlorite and chlorhexidine.

To achieve successful endodontic treatment, the clinician should be aware of root canal anatomy and its variations. Finding mandibular premolars with three canals is rare and its prequency has been reported to be 0.46%. Undetected extra roots and canals are a major reason for failed root canal treatment. This report describes diagnosis and endodontic treatment of a mandibular second premolar with three canals, two orifices in buccal and one in lingual, and a mandibular first premolar with two orifices in lingual and one in buccal. Different studies report low prevalence of mandibular premolars with three canals, so careful evaluation by radiographic and clinical examinations, use of magnification devices, fiber optics and dyes is required for successful detection and access to extra root canals.