Affiliation: | Preventive Oral Health Unit, National Dental Hospital (Teaching) Sri Lanka, Ward Place, Colombo 700700, Sri Lanka;Department of Oral and Maxillofacial Surgery, Faculty of Dental Sciences, University of Peradeniya, Peradeniya 20400, Sri Lanka;Oral & Maxillo-Facial Unit, Teaching Hospital (Karapitiya), Galle 80000, Sri Lanka;Department of Medical Laboratory Science, General Sir John Kotalawala Defense University, Ratmalana 10390, Sri Lanka |