Ribas BR, et al. Imaging Sci Dent. 2020 Dec;50(4):281-290. https://doi.org/10.5624/isd.2020.50.4.281

This study evaluated the efficacy of Cryptocarya spp extracts on biofilm of Candida albicans and its biocompatibility. Mature biofilm of C. albicans was formed on denture base acrylic resin samples and the fungicidal effect of the extracts was evaluated by Alamar Blue® assay, counting colony-forming units (CFU/mL) and confocal laser scanning microscopy (CLSM). Cytotoxicity of extracts from Cryptocarya species was evaluated by AlamarBlue® assay, using normal oral keratinocytes (NOK) cells. In additional, Analysis of plant extracts by ultra-high-performance liquid chromatography–diode array detector–tandem mass spectrometry (UPLC-DAD-MS) was performed. The results showed significant reduction in the cellular metabolism and in the number of CFU/mL of C. albicans (p<0.05). The concentration of 0.045 g/mL completely inhibited the number of CFU/mL. Regarding cytotoxicity, all extracts decreased cell viability compared to the control group. CLSM analysis showed predominance of live cells, but with a great difference between the groups. Antimicrobial activity of extracts from Cryptocarya on C. albicans biofilm was confirmed. However, all extracts showed toxicity on NOK cells.

Studies assessing the long-term effects of brushing with cleaning and disinfecting agents on surface roughness and biofilm accumulation on the three-dimensionally (3D) printed resins remain scarce. This study aimed to evaluate the effects of different solutions and simulated brushing times on the surface roughness and biofilm formation on heat-cured and 3D-printed denture base resins. Discs samples (10 mm × 1.2 mm) were prepared and randomly assigned to brushing treatments using the following solutions: distilled water, disinfectant liquid soap and dentifrice. The specimens (n = 9) were subjected to 10,000, 20,000 and 50,000 cycles to simulate 1, 2 and 5 years of brushing, respectively. The control group consisted of unbrushed samples. Surface roughness (Ra) was measured. Candida albicans biofilm formation was evaluated by counting colony forming units, cellular metabolic activity, and qualitative and quantitative analysis through confocal fluorescence microscopy. A significant increase in roughness was observed in both resins after two years of simulated brushing, mainly with dentifrice. After two years of brushing, an increase in the number of cells and metabolism of C. albicans was observed, in agreement with the fluorescence and biofilm thickness results. Brushing with dentifrice increased the roughness of heat-cured and 3D-printed resins and potentially increased C. albicans biofilm formation.

To evaluate the effect of antiseptic soap on single and dual-species biofilms of Candida albicans and Streptococcus mutans on denture base and reline resins. Samples of the resins were distributed into groups (n = 9) according to the prevention or disinfection protocols. In the prevention protocol, samples were immersed in the solutions (Lifebuoy, 0.5% sodium hypochlorite solution and PBS) for 7, 14 and 28 days before the single and dual-species biofilms formation. Overnight denture disinfection was simulated. In the disinfection protocol, samples were immersed in the same solutions during 8 hours after the single and dual-species biofilms formation. Antimicrobial activity was analyzed by counting colony-forming units (CFU/mL) and evaluating cell metabolism. Cell viability and protein components of the biofilm matrix were evaluated using confocal laser scanning microscopy (CLSM). Data were submitted to ANOVA, followed by Tukey’s post-test (α = 0.05) or Dunnett’s T3 multiple comparisons test. In the prevention protocol, Lifebuoy solution effectively reduced the number of CFU/mL of both species. In addition, the solution decreased the cell metabolism of the microorganisms. Regarding disinfection protocol, the Lifebuoy solution was able of reduce approximately of 2–3 logs for all the biofilms on the denture base and reline resin. Cellular metabolism was also reduced. The images obtained with CLSM corroborate these results. Lifebuoy solution was effective in reducing single and dual-species biofilms on denture base and reline resins.

This in-vitro study aimed to evaluate the antibacterial efficacy and color changes induced by different chemical agents on the orthodontic aligners. The sample consisted of Invisalign® aligners materials and seven solutions were tested: sodium hypochlorite (HYP), sodium bicarbonate (BIC), neutral detergent (DET), chlorhexidine gluconate (CX), white vinegar (VIN) diluted in water (1:3), Corega Tabs® effervescent tablets (COR), and distilled water (DW, control group). The microbiological control was evaluated by analyzing cell proliferation (CFU/ml) and cell metabolism (AlamarBlue® test), and the VITA EasyShade® Advance spectrophotometer was used for color change analysis, using multiple Mann-Whitney tests. All solutions significantly reduced S. mutans biofilm (CFU/mL), except for the control group. The AlamarBlue® analysis showed a significant reduction in cell viability, except for the BIC solution (p=0.183). After 7 days, HYP showed significant color variation, compared to all the other solutions, except for the control group (p=0.095). After 14 days, BIC and CX showed significantly greater color variation than the control group (p=0.007). DET showed a large difference compared to BIC and CX (p=0.007), and a statistically significant difference compared to VIN and COR (p=0.015). The disinfectant solutions HYP, DET, CX, VIN, and COR significantly reduced the bacterial colonies of S. mutans and cellular metabolism. In addition, HYP, BIC, CX, and COR significantly affected the material color.

Vários fatores contribuem para alterações nos dentes e consequentemente no sorriso, como escurecimento dental, cárie, envelhecimento, erosão química e diastemas. Com o aprimoramento do tratamento de superfície da cerâmica e da adesão aos substratos, os laminados cerâmicos garantiram espaço definitivo no panorama odontológico, tendo em vista longevidade e resultado final funcional e estético. É nesse cenário que surge o presente estudo, cujo objetivo é apresentar detalhadamente a técnica de fechamento de diastemas com uso de laminados cerâmicos. Paciente do sexo feminino compareceu a Clínica de Odontologia da Universidade Ceuma (São Luís-MA), tendo como queixa principal desconforto estético do seu sorriso. Ao exame clínico foi detectado a presença de diastema que persistiu mesmo após tratamento ortodôntico. O tratamento iniciou a partir do clareamento dentário seguido da gengivoplastia do elemento dental 22 que apresentava desarmonia no zênite gengival. Em seguida foram realizadas as etapas do tratamento reabilitador com laminados cerâmicos até a cimentação. Os laminados cerâmicos representam soluções estéticas e funcionais de alta qualidade para fechamento de diastemas. O sucesso está ligado diretamente com a correta indicação e planejamento, ao preparo suficientemente invasivo, conhecimento das técnicas e materiais, obtendo assim um sorriso estético e harmonioso, com grande garantia de longevidade.