Assessment and comparison of toothpastes for pH and antibacterial effect against Streptococcus mutans: An in vitro study

Abstract

Introduction: One of the universally practiced oral hygiene measures is tooth brushing with toothpaste. Each toothpaste is composed of different ingredients. The extent of the antimicrobial activity of toothpastes against cariogenic bacteria is still unclear. Toothpaste with the correct pH will help to neutralize the acidic activity of the oral cavity. However, there are lack of studies to determine pH of different toothpastes. Aim: The aim is to assess and compare the commercially available toothpastes for pH and antibacterial activity against Streptococcus mutans. Materials and Methods: Commercially available toothpastes composed of varying ingredients available in the local market were included in the study. The pH of the toothpastes was assessed using pH meter. The antimicrobial activity was assessed by making serial dilutions for each selected toothpastes in 1:1, 1:2, 1:4, and 1:8 ratio using distilled water. At different concentrations, the antimicrobial activity of the toothpastes against S. mutans was determined by the agar well diffusion method. The diameter of zones of inhibition (mm) was measured for assessing the antimicrobial activity. Results: The mean pH of toothpastes ranged from 7.262 ± 0.414 to 7.729 ± 0.534. All toothpastes showed antimicrobial activity against S. mutans in all four dilutions 1:1, 1:2, 1:4, 1:8. Data were analyzed using the Statistical Package for the Social Sciences version 22 software (IBM Corporation). - Analysis of Variance was used to analyze data. Conclusion: The present study showed that the pH of all the toothpastes are above that of critical pH. All the toothpastes had shown antimicrobial activity against S. mutans at varying dilutions.