Optical parameters and hardness of two maxillofacial elastomers after immersion in different solutions of Brazilian green propolis extract

A Systematic Review on Maxillofacial Prosthesis with Respect to Their Color Stability

The aim of this systematic review was to identify and analyze the findings of various studies that analyzed the changes in the color stability of maxillofacial prosthetic materials after the addition of various colorants and nanoparticles and assess the change in color after being subjected to either natural or artificial accelerated aging as well as outdoor aging. This systematic review was conducted in accordance with the guidelines of transparent reporting of systematic reviews and meta-analysis (PRISMA Statement). The primary objective of this systematic review was to evaluate the color stability of maxillofacial prosthesis. The secondary objective was to assess the effect of various colorants; pigments; opacifiers; UV absorbers-such as inorganic colorants (dry earth pigments); metal oxides; and organic colorants. The time period of the included studies extended from 2013 to 2023. Electronic database search identified a total of 217 studies. Ten studies were included to meet the research question. All 10 included studies analyzed the effect of various colorants and their exposure to various aging and weathering conditions. It was found that various pigments and nanoparticles had an effect on the color stability. Also weathering and aging conditions had a direct effect on the color stability as well. In terms of disinfection, although there was not much color difference observed, highest change in color stability was observed when rubbing or brushing of the prosthesis was carried out. In conclusion, the color stability of maxillofacial prosthetics is a critical factor that influences both patient satisfaction and the overall cosmetic look. The potential of pigments and nanoparticles to enhance the color stability of silicone-based maxillofacial prosthesis has received much research. By avoiding color fading and discoloration brought on by environmental variables including UV radiation, aging, and chemical exposure, the inclusion of various pigments and nanoparticles has been demonstrated to improve the color stability of silicone maxillofacial prostheses.

Disinfectant effects of Brazilian green propolis alcohol solutions on the Staphylococcus aureus biofilm of maxillofacial prosthesis polymers

STATEMENT OF PROBLEM

Brazilian green propolis may be an alternative product that reduces the development of a microbial biofilm on the polymers used for maxillofacial prostheses. However, its effects as a disinfectant have not been fully established.

PURPOSE

The purpose of this in vitro study was to investigate the effects of Brazilian green propolis alcohol solutions against the Staphylococcus aureus biofilm on polymers used in maxillofacial prostheses, the maxillofacial silicone elastomer (MDX4-4210), and specific acrylic resins for ocular prostheses.

MATERIAL AND METHODS

A total of 324 disk-shaped specimens (3×10 mm) of each material were fabricated. All specimens were contaminated with S. aureus (10⁸ cells/mL) to assess the antibiofilm activity of immersion solutions and protocols. Thus, 162 specimens of each material were randomly distributed and equally divided into 5 groups of disinfectants and 1 control group: 3 separate groups of 2.5%, 5%, and 10% propolis alcohol solutions, 1 group of 5% propolis alcohol gel, a positive control group of 2% chlorhexidine gluconate, and a negative control group of distilled water. Specimens (n=9) were disinfected by immersion for 5, 10, and 15 minutes and immersed in culture medium for 24 hours. Any notable turgescence in the final medium was considered indicative of a biofilm. The effects of disinfectants were analyzed by a turbidity assay and by scanning electron microscopy. Data were analyzed descriptively.

RESULTS

The final medium with specimens disinfected with 10% propolis alcohol solution showed no turbidity, indicating constant efficacy against the S. aureus biofilm. Similarly, these findings were observed in the 2% chlorhexidine gluconate group. Scanning electron microscopy images demonstrated that the surface of the polymers treated with 10% propolis alcohol solution did not show bacterial colonies.

CONCLUSIONS

Disinfection with 10% green propolis alcohol solution was effective in eliminating the S. aureus biofilm from specimens of maxillofacial elastomer and N1 acrylic resin specific to ocular prostheses by immersion for 5 minutes.

Fungicidal Effect of Lemongrass Essential Oil on Candida albicans Biofilm Pre-established on Maxillofacial Silicone Specimens

Aims:

This in-vitro study aimed to evaluate the efficacy of lemongrass (Cymbopogon citratus) essential oil in eradicating Candida albicans biofilm pre-established on the maxillofacial silicone specimens.

Materials and Methods:

Two maxillofacial silicones, namely, MDX4-4210 and Multisil Epithetik, were used for the fabrication of 6 mm diameter disks (n = 21 for each brand of silicone). A 48-h mature C. albicans ATCC 10231 biofilm was pre-established on sterile silicone specimen. These disks were then exposed to various concentrations of lemongrass essential oil ranging from 0.31% to 5% (v/v), 20% (v/v) nystatin, and RPMI-1640 medium for 18–20 h. After exposure, the remaining viable fungal biofilm was examined by the XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide]-reduction assay. All data were analyzed by using a regression coefficient and a post hoc Tukey HSD multiple comparisons test (α = 0.05).

Results:

Different brands of silicone used for fabrication did not significantly affect the formation of mature C. albicans biofilm (P =0.302). A 5% (v/v) lemongrass essential oil significantly eliminated fungal biofilm by approximately 95% (P =0.031). However, less than 50% of the fungal biofilm was eliminated by the tested oil at a concentration as low as 0.31% (v/v). Furthermore, the fungicidal efficacy against C. albicans biofilm of lemongrass essential oil at 2.5% (v/v) was as potent as that of 20% (v/v) nystatin suspension (P = 0.99).

Conclusion:

Lemongrass essential oil expressed fungicidal effect on C. albicans biofilm pre-established on the disks fabricated from different brands of silicone. Additionally, the fungicidal effectiveness of the oil against the mature fungal biofilm was dose-dependent.

Antimicrobial effects of photodynamic therapy on Staphylococcus aureus biofilm grown on a specific acrylic resin surface for ocular prostheses

BACKGROUND

Photodynamic therapy (PDT) is a treatment for the specific control of oral biofilms. However, its effects on maxillofacial prostheses have been barely explored. In this study, we evaluated the antimicrobial effect of PDT using methylene blue (MB) and laser against a Staphylococcus aureus biofilm developed on the surface of scleral acrylic resin.

METHODS

Sixty-six specimens of acrylic resin designed for ocular prostheses were fabricated in a disk-shaped format (3 × 10 mm). S. aureus biofilm was grown on the surface of the specimens for 24 h and the disks were then treated with MB at different concentrations (25, 50, 75 or 100 μg/mL), with or without PDT (GaAlAs diode laser; 660 nm; 100 mW; 9 J; 321.4 J.cm^-2; 3.5 W.cm^-2 and 90 s). Control groups were treated with 2% chlorhexidine gluconate (CHX) or phosphate buffered saline. After the treatments, colony forming units (CFU) were counted and the samples were qualitatively evaluated by scanning electron microscopy (SEM). Data were analyzed descriptively and by nested ANOVA and the Tukey test (α = .05).

RESULTS

PDT groups with MB concentrations at 75 and 100 μg/mL formed fewer CFU compared to the other groups (P < 0.001) and the 2% CHX group did not form any CFU. SEM images revealed that the surface of the polymers in these groups did not show bacterial colonies.

CONCLUSIONS

PDT significantly reduced S. aureus biofilm in the scleral acrylic resin when associated with an MB dilution of 75 μg/mL or higher. Thus, PDT can be a promising candidate for disinfecting ocular prostheses.