Comparison of probiotic and regular toothpaste effects on dental plaque and caries-causing bacteria in adolescents

Comparison of the effects of probiotic toothpaste and regular toothpaste on plaque accumulation and Streptococcus mutans colonization in high-risk caries students in the upper secondary school, a Randomized Controlled Trial study

Status

Active, not recruiting

Phases

Unknown

Study type

Interventional

Source

IRCT

Registry ID

IRCT20240303061155N6

Enrollment

Registered

2026-05-03

Start date

2026-06-20

Completion date

Unknown

Last updated

2026-06-01

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

None listed

Interventions

Intervention 1: Intervention group: participants use a probiotic toothpaste containing Lactobacillus reuteri. They are instructed to brush their teeth twice daily (morning and evening) for two minutes

Eligibility

Sex/Gender

All

Age

16 Years to 18 Years

Inclusion criteria

Inclusion criteria: Age between 16 and 18 years Routine use of toothbrush and toothpaste Being classified as high caries risk based on ADA Caries Risk Assessment No systemic disease or immunodeficiency Written informed consent from parents or legal guardians No antibiotic use during the past month

Exclusion criteria

Exclusion criteria: Allergy to toothpaste ingredients or probiotic products Use of any mouthwash or fluoride varnish within the past month Non-compliance with follow-up or study protocol

Design outcomes

Primary

Measure	Time frame
Dental plaque accumulation. Timepoint: Day 0 (baseline) and Day 30 (post-intervention). Method of measurement: Clinical dental examination and scoring of plaque index from 0 to 3.;Streptococcus mutans colonization. Timepoint: Day 0 (baseline) and Day 30 (post-intervention). Method of measurement: Saliva collection, culture on selective media, and colony counting (CFU/mL).	—

Secondary

Measure	Time frame
Local adverse effects related to toothpaste use. Timepoint: During the 30-day intervention period. Method of measurement: Clinical observation and participant self-report (e.g., irritation, sensitivity).	—

Countries

Iran (Islamic Republic of)

Contacts

Public ContactMaryam ?Fazli

Zanjan University of Medical Sciences

drfazli@zums.ac.ir+98 24 3314 8279

Outcome results