# Analysis of the Mechanical and Biofilm-Inhibitory Antimicrobial Properties of a Dental Tissue Conditioner Incorporating Ocimum Gratissimum Essential Oil: An In Vitro Study

## TL;DR

This study shows that adding Ocimum gratissimum essential oil to dental tissue conditioners can reduce biofilm formation by certain microbes for up to three days without affecting bond strength.

## Contribution

The novel contribution is demonstrating the dose-dependent biofilm inhibition of Candida albicans and Streptococcus mutans by Ocimum gratissimum EO in dental tissue conditioners.

## Key findings

- Tissue conditioners with 2% Ocimum gratissimum EO showed antimicrobial activity against biofilms on both day 1 and day 3.
- Tensile bond strength increased on day 1 with EO addition but returned to baseline by day 7.
- EO-infused conditioners lost antimicrobial effects by day 5 and day 7 postinoculation.

## Abstract

Objectives: This study aimed to investigate the tensile bond strength (TBS) and biofilm-inhibitory antimicrobial properties of tissue conditioners combined with Ocimum gratissimum essential oil (EO) at varying concentrations.

Materials and Methods: The original tissue conditioner was used as the control, while the experimental groups consisted of tissue conditioners incorporating O. gratissimum EO at concentrations of 1% and 2% (v/v) in the liquid component. The TBS between the tissue conditioner and denture base acrylic resin was measured using a universal testing machine. To evaluate biofilm-inhibitory antimicrobial properties, cylindrical specimens infused with EO were prepared and incubated with Candida albicans and Streptococcus mutans. The crystal violet assay was utilized to quantify microbial biofilm formation.

Results: The incorporation of O. gratissimum EO into tissue conditioners significantly increased the TBS on day 1 (p  < 0.05) but showed no effect by day 7 post-polymerization (p  > 0.05). Additionally, tissue conditioners containing 1% EO exhibited biofilm-inhibitory antimicrobial properties on day 1 (p  < 0.05), whereas those with 2% EO demonstrated biofilm-inhibitory antimicrobial activity on both days 1 and 3 postinoculation (p  < 0.05). By day 5 and 7, EO-infused tissue conditioners no longer exhibited biofilm-inhibitory antimicrobial properties (p  > 0.05).

Conclusion: Tissue conditioners infused with O. gratissimum EO effectively reduced the formation of biofilms by C. albicans and S. mutans in a dose–dependent manner on days 1 and 3. As tissue conditioners are typically replaced every 3–7 days, O. gratissimum EO can be incorporated as an additive to lower the formation of biofilms by C. albicans and S. mutans without compromising the TBS of the tissue conditioner to denture base acrylic resin.