A case-control study published in 2009 did find that college-aged men with oral HPV infections had more open-mouth kissing partners and oral sex partners than men who did not have oral HPV infections. Furthermore, kissing and HPV were associated even for young men who had never had oral sex.
Therefore, it does seem that french kissing, or other open-mouth kissing, may lead to HPV transmission. However, it is important to know that the numbers involved in the study were small and that the study results should be treated with caution until they are confirmed in a larger population. In addition, since most cases of HPV oral infection will resolve on their own over time, and not lead to long term complications such as throat or mouth cancer, discovering that you have kissed someone who may have been exposed to oral HPV should not lead to panic.
Historically, scientists have believed that up to 80 percent of the sexually active population will be infected with HPV at some point during their lives, even though most of them will never know it. The prevalence of infection may change now that two HPV vaccines -- Gardasil and Cervarix -- are available, but the virus is likely to remain common for quite a few more years. Therefore, although it's a good idea to discuss any known exposures when you have your pre-sex chat with a new partner, it's also important to remember that most sexually active people will have been exposed to HPV at some point during their sexual lives, whether they realize it or not.
D'Souza G, Agrawal Y, Halpern J, Bodison S, Gillison ML. Oral sexual behaviors associated with prevalent oral human papillomavirus infection. J Infect Dis. 2009 May 1;199(9):1263-9.
Kreimer AR. Oral sexual behaviors and the prevalence of oral human papillomavirus infection. J Infect Dis. 2009 May 1;199(9):1253-4.