[Assessing the knowledge and practice of general dentists of Qazvin on prophylaxis against infective endocarditis prior to dental procedures [2010-2011]]

Background: Infective endocarditis is a rare condition that can occur as a result of invasive dental procedures in susceptible patients. In order to prevent this event, appropriate antibiotics must be prescribed for the susceptible patients

Objective: The present study was aimed to assess the general Dentists' knowledge and practice regarding the prophylaxis of infective endocarditis prior to dental procedures in the city of Qazvin during 2010-2011

Methods: This was a cross-sectional descriptive study carried out on 91 general dentists in the city of Qazvin through census sampling method followed by assessing their knowledge and practice using a valid and reliable questionnaire. The questionnaire included demographic variables, heart disease, and the dental procedures requiring antibiotic prophylaxis and specific antibiotic regimen for different patients. The participants' knowledge scores were determined by summing the total questions answered correctly. Data were analyzed by central tendency indices, student t test, ANOVA, and Tukey multiple comparison test

Findings: The mean knowledge score of the dentists regarding the prophylaxis against infective endocarditis was 15.95 compared to the maximum total score of 28 [standard deviation: 3.04]. Seventy two respondents [79.1%] showed moderate [10-18 scores] and 19 [20.9%] with good knowledge [19-28 scores]. No significant differences regarding the knowledge scores were noted between two genders or the years after graduation. However, the dentists aged 40 years or older had significantly higher knowledge scores compared to those aged 31-40 years [P<0.05]

Conclusion: This study showed that the general dentists of Qazvin have moderate knowledge on prophylaxis against infective endocarditis, suggesting more continuous education programs have to be scheduled

Knowledge and performance among dentists regarding coagulation tests in patients with hereditary bleeding disorders and patients on anticoagulant therapy

Some of the dental procedures can cause bleeding. Bleeding control can be affected in some patients due to systemic disease or chronic anticoagulant therapy, so they may be at increased risk for bleeding events or even death following invasive dental procedures. This study was designed to evaluate the knowledge of general dentists in Qazvin city regarding coagulation tests performed in bleeding disorders during 2010-2011. A questionnaire [including 23 questions] was designed with the aid of specialists in the field of oral medicine and hematology. This questionnaire was distributed among 124 general practitioners. Data were analyzed with SPSS version 15 and T-test, one-way ANOVA and Tukey. The mean score for dentists knowledge was 8.64 +/- 1.20. There was no significant difference in the mean knowledge scores among male and female dentists. Tukey test showed a significant difference in the mean knowledge level among 31 -40 year old and over forty year old dentists [p<0.04]. This study showed that knowledge of the dentists regarding bleeding disorders is not at desirable level which requires planning for continuing education courses

Effect of post operative bleaching on marginal leakage of composite restorations

Today, the esthetic dentistry is considered as an important part of dental treatments. Regarding the increasing number of patients' demand to remove tooth discolorations, need for bleaching treatment is on rise. The effect of bleaching on microleakage of composite restorations is regarded as the main factor of composite failure. This aim of this research was to investigate the effect of pre- and post-operative bleaching on microleakage of class 5 composite restorations. This experimental study was performed on 15, carries free eruptive human third molar divided into 3 groups of 5 members each and marked as 1] case group [pre-operative bleaching group], 2] case group [postoperative bleaching group], and 3] control group [no bleaching group]. In group 1, samples were exposed to 20% carbamide peroxide-containing gel 2 hours a day for 7 days and kept in artificial saliva between the bleaching processes. After 14 days and while the bleaching were finished, class 5 cavities prepared in buccal and lingual surfaces of teeth [dimensions: 4*2*2 mm] where the gingival margin of all cavities were 1mm under the CEJ. Later, all cavities were filled with composite [Z 250/3M]. In group 2, class 5 cavities were prepared, filled with composite in a similar way and exposed to bleaching process as for group 1. In group 3, only class 5 cavities prepared and repaired without bleaching. Soon after, Samples were termocycled [500 times, at 4 and 55 °C]. The process of dye penetration was carried out by placing the samples in a solution containing 1% methylene blue for 24 hours. The teeth were later sectioned and the rate of microleakage evaluated using a stereomicroscope [magnification 40x]. The data were analyzed by Mann Whitney test. The rate of microleakage in class 5 restorations exposed to bleaching [either before or after restoration] increased at both occlusal and gingival margins. The degree of microleakage at occlusal margin was lower than gingival margin in all groups. The rate of microleakage in both occlusal and gingival margins showed a significant difference, statistically [p<0.006; p<0.014] however, no significant difference at occlusal and gingival margins of case group was observed [p=0.684; p=0.264]. Bleaching process increases the rate of microleakage following composite restoration

[ comparative study of the effect of two bonding agents on the shear bond strength of the repaired composite restorations]

Statement of Problem: One of the major problems in old composite filling reconstruction is creating powerful bond strength between the existing composite and the new composite filling. Furthermore, complete exchange of the old composite filling may jeopardize the tooth structure. In this situation, repairing the previous composite filling is more practical and the risk of pulp involvement may be decreased. No study has been done on the comparison of G-Bond and other bodings effects with or without silane usage except the manufacturers' claims

Purpose: The aim of this study was to evaluate the effect of two different bonding agents on the shear bond strength of the existing composite and the new composite filling with or without silane usage

Methods and Material: In this experimental and in vitro study, 50 cylindrical composite blocks were prepared. Ten samples were used as control group in the size of 5×6 mm [one piece composite]. The remaining 40 samples as the case groups were made in the size of 5×3 mm. The samples were stored in distilled water at 37[degree sign]c for 2 weeks. The surface of all the samples were roughened, etched and cleaned. These 40 samples were divided into 4 equal groups based on the bonding procedure and silane usage .The groups were Clearfil S[3] bond and silane [group A], Clearfill S[3] Bond only [group B], G Bond and silane [group C], and G Bond only [group D]. Then, the samples were stored in distilled water for another 2 weeks. The specimens were loaded to failure in shear mode with a crosshead speed of 0.5 mm/min until fracture. Shear bond strengths were analyzed with one way analysis of ANOVA

Result: Shear bond strength was significantly different in the 5 groups. Shear bond strength in the control group was 34.24 Mega pascal, being significantly higher than that in the other 4 groups. The averages of the shear bond strength, were 25.88, 23.14, 21.19 and 17.20 for group A, B, C and D respectively. The results showed a statistically significant difference between the 4 groups and the control group

Conclusion: The results of this study indicate that composite cohesive strength [control group] had the highest strength, whereas there was no statistical difference among the other groups

[Nasopharengial angiofibroma in the oral cavity in a 50-year-old man: a case report]

The angiofibroma is a rare benign vascular tumor that often occurs in the nasopharyn and paranasal sinuses in male adolescents. Presentation of this lesion in the oral cavity is very rare. This paper presents the case of a-50-year old male with an angiofibroma on the buccal mucus as exophytic lesion with red-brown color which had grown during 8 years. Based on the clinical findings, working diagnosis was mesenchymal tumor. After excisional biopsy, histopathologic feature proved to be angiofibroma