Biological Activities of Virgin Coconut and Virgin Olive Oil Mixture against Oral Primary Colonizers: An In Vitro Study.

AIM AND BACKGROUND: This study aimed to explore the potential synergistic interaction of virgin coconut oil (VCO) and virgin olive oil (VOO) mixture against Streptococcus sanguinis, Streptococcus mutans, and Lactobacillus casei in a single and mixture species through the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), antiadherence, and antibiofilm activities. MATERIALS AND METHODS: The broth microdilution technique was used to individually determine the MIC of both oils and an oil mixture (in the ratio of 1:1) in a 96-well microtiter plate. As for the MBC, the subcultured method was used. The fractional inhibitory concentration index (ΣFIC) was determined to identify the interaction types between both oils. The oil mixture at its MIC was then tested on its antibiofilm and antiadherence effect. RESULTS: The MIC of the oil mixture against the tested microbiota was 50-100%. The oil mixture was bactericidal at 100% concentration for all the mentioned microbes except S. mutans. The ΣFIC value was 2 to 4, indicating that the VCO and VOO acted additively against the microbiota. Meanwhile, the oil mixture at MIC (50% for S. sanguinis and L. casei; 100% for S. mutans and mixture species) exhibited antiadherence and antibiofilm activity toward the microbiota in mixture species. CONCLUSION: The oil mixture possesses antibacterial, antibiofilm, and antiadherence properties toward the tested microbiota, mainly at 50-100% concentration of oil mixture. There was no synergistic interaction found between VCO and VOO. CLINICAL SIGNIFICANCE: Children and individuals with special care may benefit from using the oil mixture, primarily to regulate the biofilm formation and colonization of the bacteria. Furthermore, the oil mixture is natural and nontoxic compared to chemical-based oral healthcare products. How to cite this article: Ng YM, Sockalingam SNMP, Shafiei Z, et al. Biological Activities of Virgin Coconut and Virgin Olive Oil Mixture against Oral Primary Colonizers: An In Vitro Study. J Contemp Dent Pract 2024;25(3):260-266.

The Efficacy of Apple Cider Vinegar at Different pH Values as an Antimicrobial Agent: An In Vitro Study.

AIMS AND BACKGROUND: This study evaluates the antimicrobial activities of commercially available 5% apple cider vinegar (ACV) against Enterococcus faecalis, Streptococcus mutans, and Lactobacillus casei. Materials and methods: Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were conducted using the broth microdilution method. Sodium hypochlorite (NaOCl) of 5.25% was used as a positive control, and comparisons were also made with acetic acid (AA) as the main ingredient in ACV. The three test bacteria treated with the most effective ACV dilution were visualized under a transmission electron microscope (TEM) for structural changes. RESULTS: Minimal inhibitory concentration was determined at 0.625% of the concentration of ACV against S. mutans and E. faecalis and 1.25% of the concentration of ACV against L. casei with two-fold serial dilutions. A concentration of 5 × 10-1% with 10-fold serial dilutions was found to be the MIC value for all three bacteria. No significant differences were found when compared with the positive control (NaOCl) (p = 0.182, p = 0.171, and p = 0.234), respectively, for two-fold serial dilutions and (p = 1.000, p = 0.658, and p = 0.110), respectively for 10-fold serial dilutions. MBC was observed to be 5% ACV for both E. faecalis and S. mutans. However, positive microbial growth was observed on the agar plate when cultured with L. casei. An independent sample t-test showed no significant differences (p > 0.05) in the antimicrobial activities between 5% ACV and 5% pure AA. TEM revealed cell wall and cytoplasmic membrane disruptions on all three bacteria at MIC value. CONCLUSION: Apple cider vinegar has antimicrobial activities against Enterococcus faecalis, Streptococcus mutans, and Lactobacillus casei at their respective MIC values. CLINICAL SIGNIFICANCE: Apple cider vinegar can be an alternative antimicrobial dental pulp disinfectant to sodium hypochlorite. Apple cider vinegar can be used safely, especially in children's dental pulp therapy and deep caries management, when adequate tooth isolation is not readily achievable. Thus, adverse reactions commonly associated with other frequently used chemical disinfectants can be avoided.

Preliminary in vitro cytotoxic evaluation of Uncaria gambier (Hunt) Roxb extract as a potential herbal-based pulpotomy medicament.

BACKGROUND: The downfall of formocresol as a pulpotomy medicament highlights the importance of cytotoxic evaluation and the establishment of a safe concentration of dental material prior to its usage in the oral cavity. Uncaria gambir is an herbal plant that possesses antimicrobial, anti-inflammatory and antioxidant properties, suggesting its potential as an alternative medicament for pulpotomy. However, there are not many studies published on its cytotoxicity, with some using non-standardised techniques and reported variable outcomes. Here, we investigated the concentration and time-dependent toxicity of Uncaria gambir extract towards the M3CT3-E1 cell line and compared it with the gold standard pulpotomy medicament: mineral trioxide aggregate (MTA). METHODS: Uncaria gambir extracts at concentrations ranging from 1000 to 7.8 µg/ml and MTA eluates at 4- and 48 h setting times were prepared. 10% dimethyl sulfoxide (DMSO) and culture media were used as positive and negative controls respectively. Cell viability on days 1, 2, 3 and 7 was analysed using Alamar Blue and Live and Dead Cell assay. Any morphological cellular changes were evaluated using transmission electron microscopes (TEM). Data were analysed using a two-way mixed Analysis of Variance (ANOVA). RESULTS: The interaction between the concentration and exposure time on the fluorescence intensity of Uncaria gambir extract and MTA 48 h was found to be statistically significant (p < 0.001). No cytotoxic effects on the cells were exerted by both MTA 48 h and Uncaria gambir extract at a concentration below 500 µg/mL. TEM analysis and Live and Dead Cell assay for both materials were comparable to the negative control. No significant differences in fluorescent intensity were observed between Uncaria gambir extract at 500 µg/mL and MTA 48 h (p > 0.05). CONCLUSION: Uncaria gambir extracts at a maximum concentration of 500 µg/mL are non-cytotoxic over time and are comparable to the MTA.

Antimicrobial Efficacy of Fruit Peels Eco-Enzyme against Enterococcus Faecalis: An In Vitro Study.

Sodium hypochlorite (NaOCl), an effective endodontic irrigant against Enterococcus faecalis (EF), is harmful to periapical tissues. Natural pineapple-orange eco-enzymes (M-EE) and papaya eco-enzyme (P-EE) could be potential alternatives. This study aimed to assess the antimicrobial efficacy of M-EE and P-EE at different concentrations and fermentation periods against EF, compared to 2.5% NaOCl. Fermented M-EE and P-EE (3 and 6 months) at various concentrations were mixed with EF in a 96-well plate incubated for 24 h anaerobically. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of M-EE and P-EE were determined via EF growth observation. EF inhibition was quantitatively measured and compared between different irrigants using the one-way analysis of variance (ANOVA), and different fermentation periods using the independent-samples T-test. M-EE and P-EE showed MIC at 50% and MBC at 100% concentrations. There was no significant difference in antimicrobial effect when comparing M-EE and P-EE at 50% and 100% to 2.5% NaOCl. P-EE at 6 months fermentation exhibited higher EF inhibition compared to 3 months at concentrations of 25% (p = 0.017) and 0.78% (p = 0.009). The antimicrobial properties of M-EE and P-EE, at both 100% and 50% concentrations, are comparable to 2.5% NaOCl. They could therefore be potential alternative endodontic irrigants, but further studies are required.