A dentist claims that smooching is excellent for dental health as it boosts saliva production and clears the mouth of bacteria and acids that cause decay.
Orthodontist Khaled Kasem thinks that people should spend four minutes a day locking lips on top of the traditional brushing and flossing.
A daily snog also reduces infection risk because bacteria from your partner’s saliva boost your immune system.
Other health benefits include stress relief, thanks to love hormones, and more youthful looks from exercising the face muscles.
But lovers might swap bad bacteria and boost the risk of decay if one of them already has dental problems.
lock lips：片語，嘴唇緊壓在一起的接吻；熱吻。例句：Directors persuade actresses to lock lips with actors they hate.（導演說服女演員和她們討厭的男演員熱吻。）
on top of sth：片語，除（尤指令人不快之事）之外（還）。例句：We missed our flight, and on top of that we had to wait seven hours for the next one.（我們沒趕上飛機，而且下一班還得再等7個小時。)