RT Journal Article SR Electronic T1 Oral sex and gum disease JF Sexually Transmitted Infections JO Sex Transm Infect FD BMJ Publishing Group Ltd SP 418 OP 419 DO 10.1136/sti.2003.009027 VO 80 IS 5 A1 E W Harville A1 J Zhang A1 M C Hatch YR 2004 UL http://sti.bmj.com/content/80/5/418.abstract AB