Kissing as a Protective Factor Against Decreased Salivary pH: Protocol for a Randomized Clinical Trial (Preprint)

BACKGROUND Kissing is a common social behavior that may influence physiological responses and impact oral health. Prior research has shown that affectionate behaviors like kissing can reduce stress and improve relationship satisfaction. However, the effects of kissing on salivary pH, particularly after consuming sugary or fermented beverages, have not been thoroughly investigated. OBJECTIVE This study aims to determine whether kissing accelerates salivary pH recovery following the consumption of sugary or fermented beverages. METHODS A randomized controlled trial will be conducted with 60 couples aged 18-30 years. Participants will be divided into 3 groups: a control group (no kissing), an experimental group where one partner consumes a beverage, and another experimental group where both partners consume a beverage. The study will measure salivary pH at baseline, after beverage consumption, and following a 40-second kiss or control period, with measurements taken every 5 minutes until the pH returns to neutral levels. The data will be analyzed using SPSS software (IBM Corporation). ANOVA will be used to compare salivary pH recovery between groups, and if assumptions of normality or sphericity are not met, alternative models such as generalized linear models or nonparametric tests will be considered. RESULTS The study is ongoing, with participant recruitment already initiated and preliminary data collection in progress. The study was funded by the Catholic University of Santiago de Guayaquil from June 2024 to June 2025. Ethics approval was obtained in June 2023. The results are expected to be published in the last quarter of 2025. CONCLUSIONS This study will provide insights into the relationship between kissing, salivary pH, and oral health, potentially offering new strategies for the prevention of dental caries. The results may challenge existing assumptions about the role of kissing in oral health. CLINICALTRIAL ClinicalTrials.gov NCT06501729; https://clinicaltrials.gov/study/NCT06501729 INTERNATIONAL REGISTERED REPORT DERR1-10.2196/65253