The perils of intimate kissing

July 10, 2015
Reporting on the effects of locking lips

Reporting on the effects of locking lips


I don't know about you, but I've kissed a lot of frogs. Some men I've met over the years are Casanovas, and others are, well, let's just say bad kissers. I once read a description of various kinds of kisses, and it's very enlightening to study the art of kissing. Bad kisses can be described as puppy dog kisses (sloppy and all over the face), a washing machine (use your imagination here), a thirsty dog who uses your face as a water bowl, and a reptile (again, please use your imagination.) There's also a kiss described online as "the dentist." This kiss is reported as someone scraping his or her teeth against yours, and I think we should rename this bad kiss "the dental hygienist" because it's more in line with what we do!

What happens in Vegas doesn't always stay in Vegas. Allow me to elaborate. Did you know that intimate kissing with full tongue contact and saliva exchange includes an important role for the microbiota and viruses present in the oral cavity?1 The oral cavity has two main types of surfaces that become colonized microbially and that includes teeth and mucosa, including the gingival sulcus, tongue, hard palate, soft palate, cheeks and lips.

Studies show that each of the different surfaces provides a range of habitats with a characteristic microbiota. Approximately 700 different and mostly anaerobic species inhabit the oral cavity. Saliva also contains a large number of bacteria, but a lot of the organisms found in saliva are shed or dislodged from other oral surfaces, such as the dorsal surface of the tongue.1

I just read an intriguing report on the effect of intimate kissing on the oral microbiota. Our microbiota are shaped by genetics, diet, age, and environment, including the people with whom we interact. The researchers investigated whether or not kissing partners share a similar oral microbiota (tongue and saliva). Turns out that partners share part of their microbiota on the surface of their tongues and saliva after kissing.

Twenty-one couples were sampled, which resulted in 84 tongue and 84 salivary microbiota samples. In comparing surfaces, microbiota in saliva is very dynamic and can change rapidly compared to the surface of a tongue, which is relatively stable. Tongue microbiota is much more similar in couples. Shared microbiota on the tongue is more evident as a long-term effect of couples living together and sharing dietary and personal care habits. On average, the salivary and tongue microbiota did not change in members of the same couple after an intimate kiss.1

What made me chuckle was the self-reported history of intimate kissing behavior in the study. All 21 couples were asked to report their last year's average intimate kiss frequency and the period of time since their last intimate kiss. Almost 75% of the men reported higher intimate kiss frequencies (10 a day) than the women of the same couples, who only reported five intimate kisses a day. Males, it seems, tend to over-report their intimate kisses. It's also been said that men over-report on their sexual behavior, too, including number of partners.1

When couples intimately kiss at a relatively high frequency (at least nine kisses per day), salivary microbiota becomes similar. Furthermore, nine kisses per day and a period of time of less than one hour and 45 minutes is needed to maintain a substantially equilibrated salivary microbiota.1

A recent issue of the "Dental Elf" newsletter reported that there's low-moderate evidence suggesting that in adults, professional plaque removal combined with oral hygiene instruction may achieve greater changes in dental plaque and gingival bleeding/inflammation when compared to no treatment.2 Why not spice up your oral hygiene message with adults by talking about Vegas? (Kidding, just kidding.) But there's no harm in discussing the data from this small study. It certainly beats the tired "interproximal cleaning" message, unless you include something fun and high-tech such as the Philips Sonicare AirFloss Pro with microburst technology or the WaterPik Water Flosser. Be sure to include tongue cleaning in your message, too, because the tongue's surface contains a true niche for microbes, which allows long-term colonization.

When you're in the mood to add a bit of humor to your patient education message, you might end up with a scenario like the one that happened to me with a total stranger. I discussed some of the study data with an adult male patient, and we ended up reminiscing about our high school kissing escapades. He said, "I didn't care back then. I just wanted to kiss and the alcohol disinfected our mouths." He was married and told me he longed for one of those long, intimate kisses. In other words, he indicated it was a long time since he'd had one. As I moved my chair a bit farther away from his face, all I could say was, "Oops. Sore subject?" We laughed together long and hard, and even though I'd never seen this patient for recare before, I knew he'd remember this hygiene visit for a long time. RDH


1. Kort et al. Shaping the oral microbiota through intimate kissing. Microbiome 2014, 2:41 (

LYNNE SLIM, RDH, BSDH, MSDH, is an award-winning writer who has published extensively in dental/dental hygiene journals. Lynne is the CEO of Perio C Dent, a dental practice management company that specializes in the incorporation of conservative periodontal therapy into the hygiene department of dental practices. Lynne is also the owner and moderator of the Evidence-Based Dental Hygiene Group (EBDH) on LinkedIn. Evidence-based periodontal therapy will be part of the group's focus, and Lynne enjoys mentoring dental hygienists in EBDH. She can be reached at [email protected] or