EVALUATION OF THE BEST METHOD TO DECONTAMINATE THE TOOTH-RESIN INTERFACE

ABSTRACT   Background: Contamination is the most common problem of the dental composites when the incremental technique is used to restore a tooth, which results in low bond strengths between the tooth and the resin composite. This study was designed to evaluate the best method to decontaminate the tooth resin interface by analysing the shear bond strength of two bonding agents used to bond a hybrid composite, Herculite XRV to a hydroxyapatite disk with and without contamination and decontamination procedures.   Methods: The hydroxyapatite discs were acid-etched, rinsed and air-dried prior to bonding. Specimens were divided into 4 groups, Control group: Normal bonding, Group 1: Contamination, normal bonding Group 2: Contamination, air-blow, normal bonding Group 3: Contamination, rinse, normal bonding. Following bond application, the composite (4mm diameter, 4 mm height) was build-up in 2 X 2 mm increments cured with an LED curing light. Specimens were stored in damp gauze sealed in a bag at 37 °C for 24 hours prior to testing. The shear bond strength was determined and mode of failure assessed using an Optical Microscope.   Results: The three-step etch and rinse adhesive, OptiBond FL, exhibited higher bond strength (43.2 ± 2 MPa) than OptiBond Solo Plus (32.3 ± 2.4 MPa) without contamination. However, OptiBond Solo plus was more resistant to bond failure and responded better to decontamination methods.   Conclusion: Air drying was found the most reliable method for decontamination. However, isolation remains the key factor in protecting the resin-tooth interface by any contamination

SYNTHESIS OF NANO - HYDROXYAPATITE AND NANO - FLUOROAPATITE PARTICLES BY SOL-GEL METHOD

Background: Hydroxyapatite is a material which resembles the composition and crystal structure of hard tissues in human body. It is being used in dentistry as a bioactive material in dental implants and is a major constituent in the bone regenerative materials. Fluoroapatite is also a bioactive material and is more stable than Hydroxyapatite. The fluoride content is anti - bacterial and is working very efficiently as a component of dental restorative materials. Objective: The objective is to synthesize the nano Hydroxyapatite and nanoFluoroapatite powder via sol-gel method, and compare the FTIR and Raman Spectrums of synthesized material with the FTIR and Raman of nano Hydroxyapatite and Fluoroapatite. Methods: The materials were synthesized by sol - gel method and then evaluated by the FTIR and Raman spectroscopy to confirm the chemical structure of both the materials. Results: FTIR and Raman Spectroscopy of the synthesized Hydroxyapatite and Fluoroapatite are then evaluated and compared with market grade materials, which confirm the presence of hydroxyl, phosphate and carbonate group in the obtained samples. Conclusion: Sol - gel is proved to be a reliable and simple method for the synthesis of nano Hydroxyapatite and Fluoroapatite particles. The obtained samples then compared with the available materials to confirm that the material synthesized is pure and chemically identical

SILORANE INCORPORATED WITH HYDROXYAPATITE AND FLUOROAPATITE –TO INVENT A NEW BIOACTIVE RESTORATIVE MATERIAL

Background: There were a number of restorative materials, which were fulfilling the requirements of a dental restorative material partially or somewhat completely with some limitations. 3M ESPE recently introduced a new dental restorative material, Filtek™ Silorane, which was claimed to fulfil the main objective completely, which was even confirmed by the recent studies. In order to make the best available dental restorative material an ideal restorative material it has to be bioactive. This study has been planned for the invention of a Silorane based bioactive material. It was proposed to incorporate the known bioactive materials (Hydroxyapatite and Fluoroapatite) in Silorane and analyze its chemical characterization. The main objective of a restorative dental material is to restore the function and aesthetics of the dental patient. Methods: Hydroxyapatite and Fluoroapatite were synthesized and incorporated in Silorane by 5, 10, 40, 50 and 60% weight ratio. The resultant samples were chemically analyzed by FTIR and Raman Spectroscopy. Results: The incorporation of synthesized Hydroxyapatite and Fluoroapatite into Silorane resulted in the innovation of a new bioactive restorative material. The resultant FTIR and Raman spectra shows that the Silorane incorporated by 40, 50 and 60% hydroxyapatite and fluoroapatite were altering the chemical structure of Silorane while spectrum of the samples with 5 and 10% of hydroxyapatite and fluoroapatite shows the apatites presence without changing the chemical structure of Silorane. Conclusion: A novel bioactive restorative material was invented by the incorporation of synthesized nano-Hydroxyapatite and Fluoroapatite into Filtek™ Silorane. The chemical characterization showed that bond was formed between the apatites and siloxane functional groups which results in the best available dental restorative material

ASSESSMENT OF HYPOCHONDRIASIS IN MEDICAL AND DENTAL STUDENTS

ABSTRACT   Background: Anxiety and depression are considered as an important mental health indicators in the community. Medical undergraduates face several emotional, mental and physical stresses during the academic years. Researches indicate that medical students experience a large amount of psychological pressure due to work required in a competitive environment, extreme working hours, examination stress, large amount of information to seek, lack of social life, responsibility of human welfare. Anxiety and depression ranks fourth as the leading cause of disability globally. Several studies suggest high prevalence depression and anxiety among medical students with distress levels consistently higher than general population. The objective was to assess the level of hypochondriasis among the medical and dental student from first year to final year.   Methodology: A cross sectional survey was conducted amongst the students of medical and dental college at Ziauddin University. The study included total 404 students from both disciplines, a pre-structured questionnaire “The Illness Altitude Scale- IAS” was given to the students after validation. SPSS version 17 was used for data analysis and p value >0.05 was considered significant.   Results: Of the total (n=450) 404 students completed the questionnaire. The average mean age was 22.05±2.6. Of the total (n=164) dental students, 10 students had mild, 83 moderate and 71 had severe hypochondriasis. Among (n=240) medical students, 13 had mild, 153 moderate and 74 had severe hypochondriasis.   Conclusion: These finding confirms the presence of hypochondriasis among the medical and dental undergraduate students, which increases from mild to severe from initial to final years