Selenium, an essential trace element, plays an important role in mammalian biology. Selenium nanoparticles (SeNPs) have gained significant importance because of its bioavailability, least toxicity, its interaction with proteins and its biocompatibility. The objective of the present study is to assess the cytotoxicity of SeNPs by testing on HepG2 cell line. The cytotoxicity of nanoparticles on HepG2 cell line was studied by MTT assay. Cytotoxicity was determined using Graph pad prim5 software. The SeNPs showed cytotoxic activity against HepG2 cell line with 77%, 63% and 33.7% of cell viability at 2μg/ ml, 4μg/ml and 30μg/ml concentration respectively. Biogenic SeNPs exhibited cytotoxic activity against the HepG2 cell line and hence warrants further research regarding its biosafety and potential oral antimicrobial agent.

Various national and international agencies have shown their concern toward proper handling, treatment and disposal of biomedical waste, asthey may cause serious infectious diseases such as hepatitis, tuberculosis, and HIV/AIDS. Most of the hospitals do not have effective disposalsystem leading to complex problem of hygiene and sanitation in hospitals. The use of disposable items has reduced the rate of infection but at the same time has increased the volume of the waste which needs to be disposed properly. Effective waste disposal can be achieved only by considering the various components of the waste management system and this should be made an integral part of hospital planning and designing.

Oral health contributes to personal wellbeing and quality of life. Use of tobacco in smoke or smokeless form is one of the driving reasons for global mortality. Also, it plays a major role in causing morbidity of major non- communicable diseases, including tooth morbidity in the form of periodontitis and tooth mortality. Therefore, the aim of the study is to find out the prevalence and association of nicotine dependence and tooth loss. A retrospective study was done using the case records of outpatients attending a private Dental College and Hospital. One month case records with a total of 100 case sheets of current smoker males were retrieved. Case sheets which recorded nicotine dependence using the Fagerstrom Test for Nicotine Dependence (FTND) and the number of tooth loss were used for data analysis. Descriptive and chi-square association were the statistical tests done. Patients of age more than 45 (27%) have a lesser dependency for the tobacco of 22.2% when compared to 15 to 30 years (39%) have tobacco dependency of 50%. In between lies the age group of 30-35 years (34%) had tobacco dependency of (27.7%), and there was no statistically significant association between level of nicotine dependency and tooth loss (P>0.05). Patients with high nicotine dependency of age 15-30 years had minimum tooth loss than patients of age more than 45years with a low level of nicotine dependency.