Effect of incorporating seed oils on the antifungal property, surface roughness, wettability, weight change, and glucose sorption of a soft liner

Antimicrobial activity of essential oils against biofilms formed in dental acrylic resin: a systematic review of in vitro studies

This study aimed to answer the question formulated according to the PICO strategy: 'Which essential oils show antimicrobial activity against biofilms formed on dental acrylic resin?' composed by population (dental acrylic resin), intervention (application of essential oils), comparison (denture cleansers, antifungal drugs, chlorhexidine, and oral mouthwashes), and outcome (antibiofilm activity). In vitro experimental studies evaluating the activity of EOs on biofilm formed on acrylic resin were included. PRISMA guidelines were followed, and the search was performed in the PubMed, Science Direct, Embase, and Lilacs databases and in the gray literature using Google Scholar and ProQuest in December 2023. A manual search of the reference lists of the included primary studies was performed. Of the 1467 articles identified, 37 were selected for full-text reading and 12 were included. Twelve EOs were evaluated, of which 11 showed activity against Candida spp., 3 against Staphylococcus aureus, and 1 against Pseudomonas aeruginosa. The EOs of Cymbopogon citratus, Cinnamomum zeylanicum, and Cymbopogon nardus showed higher action than chlorhexidine, C. nardus higher than Listerine, C. citratus higher than nystatin, and Melaleuca alternifolia higher than fluconazole and nystatin. However, chlorhexidine was more effective than Lippia sidoides and Salvia officinalis, sodium hypochlorite was more effective than L. sidoides, nystatin was more effective than Zingiber officinale, Amphotericin B more effective than Eucalyptus globulus and M. alternifolia. In conclusion, the EOs of C. zeylanicum, C. citratus, C. nardus, and M. alternifolia showed antimicrobial activity to reduce biofilm on dental acrylic resin.

Adhesion of biofilm, surface characteristics, and mechanical properties of antimicrobial denture base resin

PURPOSE

This study incorporated the nanomaterial, nanostructured silver vanadate decorated with silver nanoparticles (AgVO₃), into heat-cured resin (HT) at concentrations of 2.5%, 5%, and 10% and compared the adhesion of multispecies biofilms, surface characteristics, and mechanical properties with conventional heat-cured (HT 0%) and printed resins.

MATERIALS AND METHODS

AgVO₃ was incorporated in mass into HT powder. A denture base resin was used to obtain printed samples. Adhesion of a multispecies biofilm of Candida albicans, Candida glabrata, and Streptococcus mutans was evaluated by colony-forming units per milliliter (CFU/mL) and metabolic activity. Wettability, roughness, and scanning electron microscopy (SEM) were used to assess the physical characteristics of the surface. The mechanical properties of flexural strength and elastic modulus were tested.

RESULTS

HT 10%-AgVO₃ showed efficacy against S. mutans; however, it favored C. albicans CFU/mL (P < .05). The printed resin showed a higher metabolically active biofilm than HT 0% (P < .05). There was no difference in wettability or roughness between groups (P > .05). Irregularities on the printed resin surface and pores in HT 5%-AgVO₃ were observed by SEM. HT 0% showed the highest flexural strength, and the resins incorporated with AgVO₃ had the highest elastic modulus (P < .05).

CONCLUSION

The incorporation of 10% AgVO₃ into heat-cured resin provided antimicrobial activity against S. mutans in a multispecies biofilm did not affect the roughness or wettability but reduced flexural strength and increased elastic modulus. Printed resin showed higher irregularity, an active biofilm, and lower flexural strength and elastic modulus than heat-cured resin.

In vitro activities of carvacrol, cinnamaldehyde and thymol against Candida biofilms

Oral candidiasis is frequently associated with Candida biofilms. Biofilms are microbial communities related to persistent, recalcitrant and difficult to-treat infections. Conventional treatments are not sufficient to overcome biofilm-associated candidiasis; thus, the search of new antifungal compounds is necessary. In the current study, we have evaluated the effect of three phytocompounds, carvacrol, cinnamaldehyde and thymol, against Candida planktonic and sessile cells. Reduction in biofilm biomass and metabolic activity was assessed during adhesion and mature biofilm phases. Candida albicans was the most biofilm-producing Candida species. All phytocompounds tested were fungicidal against Candida planktonic cells. Cinnamaldehyde was the most active in inhibiting biofilm adhesion, but carvacrol and thymol significantly reduced both mature biofilm biomass and metabolic activity. These results highlight the role of cinnamaldehyde, carvacrol and thymol as promising alternatives for the treatment of candidiasis due to their antibiofilm capacities, and stress the necessity to continue studies on their safety, toxicity and pharmacodynamics and pharmacokinetics.

The effects of adding fluorescent carbon nanoparticles on various mechanical properties of denture liners

The aim of this in vitro study was to evaluate the effects of incorporating fluorescent carbon nanoparticles (FCNs) on the hardness, tear, and tensile bond strength of an acrylic-based tissue conditioner and a silicone-based soft denture liner. FCNs added to an acrylic-based tissue conditioner (Viscogel, Dentsply; Group V) and a silicone-based soft denture liner (Ufigel P, Voco; Group U) were divided into subgroups according to the concentrations (Group 0: no water, Group 1: with only water, Group 2: 0.5% FCNs, Group 3: 1% FCNs and Group 4: 10% FCNs) (n=10/per group). Shore A hardness, tear, and tensile bond strength tests were performed. Significant decreases occurred in Groups U2, U3, and U4 compared to the control groups (Groups U0 and U1) in the tear and tensile bond strength test parameters (p<0.025). However, in both types of the tested materials, there were no statistically significant differences among the shore A hardness test results (p>0.025).

Current herbal medicine as an alternative treatment in dentistry: In vitro, in vivo and clinical studies

Since the time that human population comprehended the importance of general health maintenance and the burden of disease, there has been a search for healing properties in the natural environment. Herbal medicine is the use of plants with medical properties for prevention and treatment of conditions that can affect general health. Recently, a growing interest has been observed toward the use of traditional herbal medicine alongside synthetic modern drugs. Around 80% of the population, especially in developing countries relies on it for healthcare. Oral healthcare is considered a major part of general health. According to the world health organization (WHO), oral health is considered an important part of general health and quality of life. The utilization of natural medications for the management of pathologic oro-dental conditions can be a logical alternative to pharmaceutical methods due to their availability, low costs, and lower side effects. The current literature review aimed at exploration of the variety and extent of herbal products application in oral health maintenance including different fields of oral healthcare such as dental caries, periodontal maintenance, microbial infections, oral cancers, and inflammatory conditions.

Influence of AgVO3 incorporation on antimicrobial properties, hardness, roughness and adhesion of a soft denture liner

The objective of this in vitro study was to investigate the effect of nanostructured silver vanadate decorated with silver nanoparticles (AgVO₃) on antimicrobial activity, hardness, roughness, and adhesion of a soft denture liner. The antimicrobial efficacy of the Trusoft (Boswoth) liner incorporated with different concentrations of AgVO₃ against Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans, and Staphyloccocus aureus (n = 5) was evaluated by the agar diffusion method. Roughness, hardness, and adhesion properties were also evaluated. The data were analyzed by analysis of variance (ANOVA) and Tukey's multiple comparison test with significance at the p < 0.05 level. At concentrations of 1 and 2.5%, AgVO₃ incorporation was effective only against E. faecalis, and at 5 and 10%, against E. faecalis, P. aeruginosa, and C. albicans. None of the concentrations was effective against S. aureus. A decrease in hardness was found for the 1, 2.5, and 10% AgVO₃ concentrations (p < 0.001) and at 5%, hardness was not affected. None of the concentrations affected the roughness of the material. A significant increase in tensile values was observed between the liner and heat-curing acrylic resin for 2.5% (p < 0.001) and 10% (p = 0.042) concentrations. AgVO₃ incorporation to a soft denture liner promoted antimicrobial activity against E. faecalis, P. aeruginosa, and C. albicans without affecting roughness, maintaining the hardness properties recommended for soft and extra soft liners, and improving the adhesion between the liner and the acrylic resin used for dentures.

Effects of trimethylsilane plasma coating on the hydrophobicity of denture base resin and adhesion of Candida albicans on resin surfaces

STATEMENT OF PROBLEM

Candida-associated denture stomatitis is the most common oral mucosal lesion among denture wearers. Trimethylsilane (TMS) plasma coating may inhibit the growth of Candida albicans on denture surfaces.

PURPOSE

The purpose of this in vitro study was to investigate whether TMS plasma coatings can effectively reduce C albicans adhesion on denture base acrylic resin surfaces.

MATERIAL AND METHODS

Sixty denture base acrylic resin disks with smooth and rough surfaces were prepared and were either left untreated (control group) or coated with TMS monomer (experimental group) by using plasma. Contact angles were measured immediately after TMS plasma coating. The morphology of C albicans adhesion was observed with scanning electron microscopy (SEM). Energy-dispersive spectroscopy (EDS) was used to characterize the elemental composition of the specimen surface. An adhesion test was performed by incubating the resin disk specimens in C albicans suspensions (1×10⁷ cells/mL) at 37°C for 24 hours and further measuring the optical density of the C albicans by using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay test. One-way ANOVA and 2-way ANOVA were followed by a post hoc test analysis (α=.05).

RESULTS

The group with TMS coating exhibited a more hydrophobic surface than the control group. EDS analysis revealed successful TMS plasma coating. The difference in the mean contact angles between the uncoated group and the TMS-coated group was statistically significant (P<.05), 79.0 ±2.9 degrees versus 105.7 ±1.5 degrees for the smooth surface and 90.2 ±7.6 degrees versus 131.5 ±2.1 degrees for the rough surface. In SEM analysis, the C albicans biofilm was found to grow more on the surface of the denture base resin without the TMS coating than on the surfaces of the experimental group. In the adhesion test, the amount of C albicans adhering to the surface of denture base resin with the TMS coating was significantly less than that on the surfaces without TMS coating (P<.05).

CONCLUSIONS

TMS coating significantly reduced the adhesion of C albicans to the denture base resin and may reduce denture stomatitis.