In search for natural products with antimicrobial properties for use in the prevention and treatment of peri-implantitis, the purpose of this investigation was to evaluate the antimicrobial activity of curcumin and xanthohumol, using an in vitro multi-species dynamic biofilm model including Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. The antimicrobial activities of curcumin (5 mM) and xanthohumol (100 μM) extracts, and the respective controls, were evaluated with 72-h biofilms formed over dental implants by their submersion for 60 seconds. The evaluation was assessed by quantitative polymerase chain reaction (qPCR), confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). For the data analysis, comparisons were tested applying ANOVA tests with post-hoc Bonferroni corrections to evaluate the antimicrobial activity of both extracts. With qPCR, statistically significant reductions in bacterial counts were observed for curcumin and xanthohumol, when compared to the negative control. The results with CLSM and SEM were consistent with those reported with qPCR. It was concluded that both curcumin and xanthohumol have demonstrated antimicrobial activity against the six bacterial species included in the dynamic in vitro biofilm model used.

Objectives: The objective of this study is to qualitatively and quantitatively evaluate biofilm formation on hybrid titanium implants (HS), with moderately rough and turned surface topographies.Materials and Methods: A validated dynamic in vitro multispecies biofilm model, based on bacterial growth under flow and shear conditions resembling the oral cavity, was used to evaluate biofilm formation on the tested implant surfaces. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to compare the biofilm structure and microbial biomass deposited on either the moderately rough or the turned surface of HS. Quantitative polymerase chain reaction (qPCR) was used to evaluate the total bacterial counts and counts of each specific bacterium in biofilms formed on implants with either the moderately rough or the turned surfaces, as in the hybrid titanium implants, after 24, 48 and 72 h. A general linear model was applied to compare the CLSM and qPCR results between the tested implant surfaces.Results: A significantly higher bacterial biomass grew on the moderately rough implant surfaces, compared to the turned surface area of HS implants (p < .05), at all incubation times, as evidenced with both CLSM and SEM. qPCR analysis also demonstrated an important increase in the total and specific bacterial counts in moderately rough surface implants at the three incubation times.Conclusions: Implant surface topography (moderately rough versus turned) significantly influenced in vitro biofilm formation in terms of biofilm structure, bacterial biomass and quantity of the specific species selected for the model used.

This study aimed to evaluate the impact of Candida albicans on subgingival biofilm formation on dental implant surfaces. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to compare biofilm structure and microbial biomass in the presence and absence of the fungus after periods of 24, 48, and 72 h. Quantitative polymerase chain reaction (qPCR) was used to quantify the number of viable and total micro-organisms for each of the biofilm-forming strains. A general linear model was applied to compare CLSM and qPCR results between the control and test conditions. The biofilm developed with C. albicans at 72 h had a higher bacterial biomass and a significantly higher cell viability (p < 0.05). After both 48 and 72 h of incubation, in the presence of C. albicans, there was a significant increase in counts of Fusobacterium nucleatum and Porphyromonas gingivalis and in the cell viability of Streptococcus oralis, Aggregatibacter actinomycetemcomitans, F. nucleatum, and P. gingivalis. Using a dynamic in vitro multispecies biofilm model, C. albicans exacerbated the development of the biofilm grown on dental implant surfaces, significantly increasing the number and cell viability of periodontal bacteria.

This study aimed to evaluate the impact of Candida albicans on subgingival biofilm formation on dental implant surfaces. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were used to compare biofilm structure and microbial biomass in the presence and absence of the fungus after periods of 24, 48, and 72 h. Quantitative polymerase chain reaction (qPCR) was used to quantify the number of viable and total micro-organisms for each of the biofilm-forming strains. A general linear model was applied to compare CLSM and qPCR results between control and test conditions. The biofilm developed with C. albicans at 72 h had a higher bacterial biomass, with a significantly higher cell viability (p < 0.05). After both 48 and 72 h of incubation, in the presence of C. albicans, there was a significant increase in counts of Fusobacterium nucleatum and Porphyromonas gingivalis and in the cell viability of Streptococcus oralis, Aggregatibacter actinomycetemcomitans, F. nucleatum, and P. gingivalis. Using a dynamic in vitro multispecies biofilm model, C. albicans exacerbated the development of the biofilm grown on dental implant surfaces, significantly increasing the number and cell viability of periodontal bacteria.

The aim of this in vitro study was to evaluate the effect of xanthohumol and thymol on the impact of Candida albicans on the structure, size and cell viability of subgingival biofilms formed on dental implant surfaces. The structure and microbial biomass of biofilms developed after 72 h, treated and untreated with both extracts, were compared by scanning electron microscopy (SEM) and confocal laser microscopy (CLSM). Quantitative polymerase chain reaction (qPCR) was used to quantify the number of viable and total microorganisms of each of the biofilm-forming strains in each condition. A general linear model was used to compare and validate the CLSM and qPCR results. The presence of xanthohumol and thymol during biofilm development inhibited the filamentous growth of C. albicans. The biofilm incubated with xanthohumol had significantly lower bacterial biomass and cell viability than the biofilm not exposed to the extract (p < 0.05). In contrast, these global parameters showed no differences when the biofilm was incubated with thymol. In the presence of xanthohumol, there was a decrease in counts and cell viability of Fusobacterium nucleatum, Porphyromonas gingivalis, and Aggregatibacter actinomycetemcomitans. Thymol treatment reduced the viability of F. nucleatum and P. gingivalis. The presence of these vegetable extracts during the development of a dynamic in vitro multispecies biofilm model inhibited the filamentous growth of C. albicans, partially reversing the effect that the fungus exerted on the structure, size and vitality of periodontopathogenic bacteria.