Evaluation of various concentrations of alkaline surface treatment on interfacial bond strengths of amalgam bonded to amalgam.

This study was done to assess the influence of alkaline surface modification on interfacial bond strength of existing fractured (old) amalgam restoration bonded to fresh amalgam. Old and Fresh amalgam interfaced samples were prepared by applying a 4-methacryloyloxyethy trimellitate anhydride (4-META) containing adhesive. The adhesive used was Amalgabond (Parkell, Farmingdale, NY 11735, USA). Four concentrations of calcium hydroxide Ca(OH)2 solutions were used as a surface modifiers for old amalgam to increase the pH of the amalgam surfaces. The concentrations used were 2.5, 5, 10 and 15%. Direct measurement of the interfacial bond strength was carried out using an electromechanical universal tensile testing machine at crosshead speed of 10mm per minute. Results show that all the calcium hydroxide modified samples produced the increased tensile bond strength (TBS) as compared to their control group. The highest values of bond strength were achieved using 15% Ca(OH)2 solution as surface modifier. Pretreatment of fractured amalgam with calcium hydroxide improves the bond strength of 4-META adhesives. Its use in repair of amalgam may therefore be considered.

Teachers' knowledge about oral health and their interest in oral health education in Hail, Saudi Arabia.

OBJECTIVES: To assess the dental health knowledge and the interest of secondary school teachers in imparting oral health education in Hail, Saudi Arabia. METHODS: It was a questionnaire based cross-sectional survey of secondary school teachers in Hail, Saudi Arabia, carried out from November 2014 to January 2015. A validated self-administered questionnaire was used to determine teachers' oral health knowledge and their interest in participating in oral health education of school children. Data analysis was performed using SPSS version 20 statistical software. RESULTS: Two hundred and twenty three secondary school teachers responded to the survey. Results showed that about 80 to 90 % of teachers had sufficient knowledge of causes and prevention of dental caries and gingivitis. About 94% of teachers agreed that they can play an effective role in oral health promotion while 96% were found to be interested in performing additional duty as oral health promoter. A large majority (91.9 %) had the opinion that oral health education must be included in school curriculum. CONCLUSION: Teachers in Hail region had adequate amount of knowledge regarding oral health, and they were interested to play their role in promoting oral health education. Based on the findings of this study, it is recommended to include dental health education in curriculum at secondary school level and to provide sufficient training to teachers to enable them to participate actively in oral health promotion activities.