[1] Post Grad Inst Med Educ & Res, Oral Hlth Sci Ctr, Chandigarh, India
[2] Post Grad Inst Med Educ & Res, Dept Internal Med, Chandigarh, India
[3] Univ Helsinki, Dept Oral & Maxillofacial Dis, Helsinki, Finland
[4] Helsinki Univ Hosp, Helsinki, Finland
[5] Karolinska Inst, Dept Oral Dis, Stockholm, Sweden
[6] Post Grad Inst Med Educ & Res, Dept Virol, Chandigarh, India
[7] Maulana Azad Dent Coll, New Delhi, India