Kissing as a Protective Factor Against Acidic pH in Saliva

April 21, 2026 updated by: Fernando Armijos Briones, Universidad Catolica Santiago de Guayaquil

Potential Effect of Oral Kissing Between Two People Against the Decrease in pH

The pH of saliva can be acidic or alkaline; When it is acidic, the tooth enamel is demineralized, that is, weakened. Additionally, bacteria in the mouth can increase and cause infections such as cavities. This occurs when we consume sugary or fermented drinks, such as soda or beer.

The intention of the research team is to give some of these drinks to the study participants and verify the decrease in salivary pH. Next, a group of people will be asked to kiss their partner on the mouth, and then the pH will be measured again to see if it increases, that is, if it stops being acidic faster than in the group that did not kiss.

The aim is to demonstrate that kissing on the mouth between two people can protect teeth from cavities by rapidly increasing the pH of saliva after it has decreased to become acidic.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The goal of this intervention study will be to determine if oral kissing between two people can increase salivary pH more quickly after drinking artificial juices, soft drinks, or (non-alcoholic) beers. It will also be studied whether the pH restoration time is faster when only one person kisses one of the named drinks or when both people do it. The main questions that are intended to be answered are the following:

  • Is the act of kissing on the mouth capable of increasing the pH of saliva more quickly than physiologically after consuming a sugary or fermented drink that has decreased it?
  • Is the increase in salivary pH after an oral kiss more accelerated when only one person consumes sugary or fermented drinks than when both people do so? The investigators will measure the basal pH of all participants before providing them with one of the drinks (artificial fruit juice, soda, or non-alcoholic beer). The researchers will then give the drinks and measure the decrease in salivary pH in all groups. Control group participants will not kiss; They will only wait for the salivary pH to neutralize physiologically. The rest of the couples will be divided into two groups: the group in which only one person in the couple consumes the sugary or fermented drink, and the group in which both people in the couple do so.

Saliva pH measurements will be performed, after initiation and consumption of the drinks, every 5 minutes for up to 40 minutes. That is, until the restoration of salivary pH is ensured in all groups.

Participants:

  • They will be between 18 and 30 years old to reduce the probability of consuming medications that alter salivary pH.
  • They should not be taking medications that alter the pH of saliva.
  • They must be in good health.
  • They should not have abscesses in the oral cavity.
  • They must have good oral health according to the loss proposed and the observed index.

Study Type

Interventional

Enrollment (Actual)

33

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Ecuador
    • Guayas
      • Guayaquil, Guayas, Ecuador, 17-11-5058
        • School of Dentistry of the Catholic University Santiago de Guayaquil

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • They must be in good health
  • They must have good oral health according to the raised loss and observed index.
  • They will be between 18 and 30 years old to reduce the probability of consuming medications that alter salivary pH.

Exclusion Criteria:

  • Be taking medications that alter the pH of saliva.
  • Have abscesses in the oral cavity

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Control
The couples in the control group will not kiss; they will only wait for the salivary pH to neutralize physiologically.
Experimental: Only one person consumes the drink
the group in which only one person in the couple consumes the sugary or fermented drink and they kiss
Other: Kiss
Participants will kiss with their partners for 40 seconds. The kiss will be on the mouth.
Experimental: Both people consume the drink
In this group, both people will consume the drinks and then kiss.
Other: Kiss
Participants will kiss with their partners for 40 seconds. The kiss will be on the mouth.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
salivary pH
Time Frame: In a period of every 5 minutes, until reaching 40 minutes, which is the time in which physiologically the pH of the saliva is neutralized.
It is expected to measure the progressive increase in pH until reaching a neutral point, which occurs physiologically between 30 to 40 minutes, and compare the time spent by the control group with that of the experimental group. Measurements will be taken every 5 minutes from the kiss, which will last 40 seconds. In total, there will be 8 measurements, not counting the initial one for surveying the baseline. The measurement will be carried out with a calibrated pH meter. People will be asked to drool into a test tube
In a period of every 5 minutes, until reaching 40 minutes, which is the time in which physiologically the pH of the saliva is neutralized.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Universidad Catolica Santiago de Guayaquil

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 30, 2024

Primary Completion (Actual)

February 20, 2025

Study Completion (Actual)

November 20, 2025

Study Registration Dates

First Submitted

July 2, 2024

First Submitted That Met QC Criteria

July 9, 2024

First Posted (Actual)

July 15, 2024

Study Record Updates

Last Update Posted (Actual)

April 24, 2026

Last Update Submitted That Met QC Criteria

April 21, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 598

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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