Physical properties of artificial teeth after immersion in liquid disinfectant soaps.

PURPOSE: To evaluate the hardness, roughness and color stability of artificial teeth after immersion in liquid disinfectant soaps. METHODS: Artificial teeth (Vipi Dent Plus, ArtiPlus and Biolux) were divided into four groups (n=15), according to the type of immersion solution: distilled water/control group (DW); liquid disinfectant soap Dettol (SD); liquid disinfectant soap Protex (SP); and liquid disinfectant soap Lifebuoy (SL). The immersion cycles occurred every day, for 8 hours at room temperature in each disinfectant solution, following immersion in distilled water for 16 hours at 37°C. All solutions were changed daily. Properties were evaluated after 0, 7, 14, 21 and 28 days of immersion. The data were analyzed with a mixed three-way ANOVA followed by the Bonferroni post-hoc test (α= 0.05). RESULTS: Vipi teeth presented significant reduction (P< 0.05) in hardness and roughness prior to 7 days of immersion in all solutions, including control group. These values, in general, were maintained during the 28 days. Biolux teeth, in general, did not present significant changes in hardness prior to immersion in any of the time intervals. The roughness of these teeth increased after 21 and 28 days of immersion (P< 0.05) in all the solutions. ArtiPlus teeth maintained stable roughness and hardness during the assessment period, regardless of the type of soap used. Color alterations were considered clinically acceptable. The liquid soaps may be an alternative for the disinfection of partial or total removable dentures. CLINICAL SIGNIFICANCE: The liquid disinfectant soaps tested did not significantly alter the hardness, roughness and color stability of the artificial teeth tested and may be an alternative for the disinfection of partial or total removable dentures.

Cytotoxicity of antimicrobial photodynamic inactivation on epithelial cells when co-cultured with Candida albicans.

This study assessed the cytotoxicity of antimicrobial Photodynamic Inactivation (aPDI), mediated by curcumin, using human keratinocytes co-cultured with Candida albicans. Cells and microorganisms were grown separately for 24 hours and then kept in contact for an additional 24 hours. After this period, aPDI was applied. The conditions tested were: P+L+ (experimental group aPDI); P-L+ (light emitting diode [LED] group); P+L- (curcumin group); and P-L- (cells in co-culture without curcumin nor LED). In addition, keratinocytes and C. albicans were grown separately, were not placed in the co-culture and did not receive aPDI (control group). Cell proliferation was assessed using Alamar Blue, MTT, XTT and CFU tests. Qualitative and quantitative analyses were performed. Analysis of variance (ANOVA) was applied to the survival percentages of cells compared to the control group (considered as 100% viability), complemented by multiple comparisons using Tukey's test. A 5% significance level was adopted. The results of this study showed no interference in the metabolism of the cells in co-culture, since no differences were observed between the control group (cultured cells by themselves) and the P-L- group (co-culture cells without aPDI). The aPDI group reached the highest reduction (p = 0.009), which was equivalent to 1.7 log10 when compared to the control group. The P+L-, P-L+, P-L- and control groups were not statistically different (ρ > 0.05). aPDI inhibited the growth of keratinocytes and C. albicans in all tests, so the therapy was considered slightly (inhibition between 25 and 50% compared to the control group) to moderately (inhibition between 50 and 75% compared to the control group) cytotoxic.

Description of a Rat Palatal Acrylic Plate That Can Be Relined.

PURPOSE: The objective of this article is to describe a method to construct an intraoral acrylic device that permits a reline material to be added to the inner surface of the palatal plate. MATERIALS AND METHODS: Fifteen 60-day-old adult female rats (Rattus Norvegicus Albinus Wistar), weighing 150 to 250 g were used for this study and allocated to three groups (n = 5): G1, animals wearing a heat-polymerized acrylic resin palatal plate (Lucitone 550) for 14 days; G2, animals wearing a heat-polymerized acrylic resin palatal plate (Lucitone 550) relined with Tokuyama Rebase II for 14 days; and G3, animals maintained under the same conditions as the experimental groups, without wearing palatal plates for 14 days. The manipulation of the animals followed the guidelines of the Brazilian College of Animal Experimentation, under the approval of the animal ethics committee of the State University of Ponta Grossa. The palatal plates covered the whole palate, were fixed in the molar region with light-cured resin, and were kept there for 14 days. The animals received a paste diet and water ad libitum. Before and after the trial period, the rats were weighed individually on a precision scale. Statistical analysis was performed using a two-way analysis of variance (α = 0.05) test for comparison of the animals' weight (g) at time 0 and after 14 days of using the palatal plate. RESULTS: No statistical differences were observed regarding the weight of the animals among the experimental groups in the study. CONCLUSIONS: The individual master impressions, the molar teeth coverage, and the method of cementation with nonadhesive composite resin provided good stability for the palatal plate showed in this study, not disturbing the eating habits and nutrition of the animals. This model seems reproducible, offering adequate histopathological evaluation. Differences in tissue morphology exist between the animals that used the palatal plate and the animals that did not use this device. Use of these palatal plates could clarify how prostheses bring changes in the palatal mucosa of users.