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Statement of Problem: Biofilms can be retained on dental prostheses leading to the development of infections. The indiscriminate use of antifungal drugs can result in the development of microorganisms that are resistant to these antimicrobial agents. Whether probiotics are a suitable alternative for reducing the prevalence of oral candidiasis is unclear., Purpose: The purpose of this in vitro study was to evaluate the influence of 6 different live strains of probiotics and 2 commercially available probiotic supplements used for inhibiting the growth of Candida albicans biofilm in heat-polymerized acrylic resin denture base material and to determine whether biofilm byproducts modify the surface of specimens., Material and Methods: Biofilms of C. albicans were formed on acrylic resin specimens in the presence of probiotics and quantified by colony-forming units (CFUs), and the surface roughness (Ra) of the specimens was assessed before and after the formation of biofilms. The CFU and roughness data were analyzed by analysis of variance and the Tukey HSD test (α=.05)., Results: A significant decrease in the number (CFU/mL) of C. albicans cells was found when they were cultured with 4 probiotics: B. lactis (P=.045), B. longum (P<.001), L. casei (P<.001), and L. helveticus (P<.001) and with the commercially available probiotic Prolive (P=.05). The Ra of specimens decreased after exposure to different microbial biofilms (P≤.05) except in 3 experimental groups., Conclusions: In general, the tested probiotics had an antagonistic effect on the growth of C. albicans, and the surface of acrylic resin was altered after exposure to biofilm byproducts., (Copyright © 2020 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Exposure of silicone prostheses to environmental factors can alter their properties, affecting longevity. However, whether nonthermal plasma (NTP) can prevent these alterations is unclear., Purpose: The purpose of this in vitro study was to evaluate the surface roughness (Ra), sorption, solubility, and color stability (ΔE 00 ) of the MDX4-4210 and A-120 silicones, with and without NTP treatment in accordance with an independent analysis of the use of 2 pigmentations., Material and Methods: One hundred sixty specimens were fabricated and distributed into 16 groups (n=10) as per the silicone, pigmentation, and NTP coating. The NTP was applied, and the Ra, sorption, solubility, and ΔE 00 were evaluated before and after accelerated aging. ANOVA was used, and the HSD Tukey test was applied (α=.05)., Results: NTP generated an increase in roughness after aging, regardless of pigmentation or silicone. A-120 silicone without NTP showed a reduction in roughness after aging, regardless of pigmentation. For sorption and solubility, the bronze pigmentation (for A-120 and MDX4-4210) presented the smallest results after NTP treatment. For MDX4-4210 with pink pigmentation and NTP, sorption decreased and solubility increased. For A-120 with pink pigmentation and NTP, sorption and solubility increased. Sorption was reduced in all situations, except for A-120 with pink pigmentation, which increased. Regardless of the silicone used, solubility was reduced after NTP for bronze pigmentation. For A-120 and MDX4-4210 with pink pigmentation and NTP, the solubility increased. For both pigmentations, the NTP treatment promoted lower color alteration only for the A-120 silicone after accelerated aging (within the acceptability threshold)., Conclusions: The NTP protocol of this study, which was applied to facial silicones, generated inconsistent results between the evaluated properties. Therefore, the NTP protocol used does not seem to be ideal for the treatment of silicone surfaces after aging., (Copyright © 2020 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Ocular prosthesis acrylic resins should be biocompatible regardless of the polymerization method. The authors are unaware of a study that evaluated the biocompatibility of ocular prostheses., Purpose: The purpose of this in vitro study was to evaluate the cytotoxicity of different methods of polymerizing ocular prosthesis acrylic resin. This was accomplished by analyzing the cell proliferation, production of proinflammatory cytokines, and expression of extracellular matrix proteins related to tissue remodeling and repair of a human conjunctival cell line., Material and Methods: Nine acrylic resin specimens were divided into 3 groups: polymerization in a water bath, by microwave, or by autopolymerization. Eluates (prepared for 72 hours) were exposed to cells for 72 hours. A medium without specimens served as negative control (nonstimulated group). The tetrazolium dye MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay was performed to evaluate the cytotoxic effect, and an enzyme-linked immunosorbent assay was executed for analysis of interleukin 1 β (IL1β), IL6, tumor necrosis factor α (TNFα), and CCL3/MIP1α production. Also, real-time reverse transcriptase (RT)-PCR was performed for analysis of mRNA expression of type IV collagen (COL IV), TGFβ, and MMP9, and data were tested using ANOVA with Bonferroni post hoc test (α=.05)., Results: Microwave-processed resin showed slight cytotoxicity due to a significant reduction in cell proliferation and an increase in IL6 quantity. Higher levels of mRNA expression of COL IV, MMP9, and TGFβ were verified in water bath-processed resin, which were similar to those in the nonstimulated group., Conclusions: Microwave-processed resin showed a significant reduction in cell proliferation and an increase in IL6 quantity. Heat-polymerized resin exhibited a higher mRNA expression of COL IV, MMP9, and TGFβ; this result was similar to that in the nonstimulated group., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Different factors can influence marginal bone loss around dental implants, including the type of internal and external connection between the implant and the abutment. The evidence needed to evaluate these factors is unclear., Purpose: The purpose of this systematic review was to evaluate marginal bone loss by radiographic analysis around dental implants with internal or external connections., Material and Methods: A systematic review was conducted following the criteria defined by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Initially, a population, intervention, comparison, and outcome(s) (PICO) question was defined: does the connection type (internal or external) influence marginal bone loss in patients undergoing implantation? An electronic search of PubMed/MEDLINE and Scopus databases was performed for studies in English language published between January 2000 and December 2014 by 2 independent reviewers, who analyzed the marginal bone loss of dental implants with an internal and/or external connection., Results: From an initial screening yield of 595 references and after considering inclusion and exclusion criteria, 17 articles were selected for this review. Among them, 10 studies compared groups of implants with internal and external connections; 1 study evaluated external connections; and 6 studies analyzed internal connections. A total of 2708 implants were placed in 864 patients. Regarding the connection type, 2347 implants had internal connections, and 361 implants had external connections. Most studies showed lower marginal bone loss values for internal connection implants than for external connection implants., Conclusions: Osseointegrated dental implants with internal connections exhibited lower marginal bone loss than implants with external connections. This finding is mainly the result of the platform switching concept, which is more frequently found in implants with internal connections., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)

Statement of Problem: Nonthermal plasma (NTP) treatment is an alternative technique for promoting the adhesion of resin cement to lithium disilicate ceramic. However, no study has evaluated whether the surface modifications are affected by atmospheric air aging., Purpose: The purposes of this in vitro study were to characterize the lithium disilicate surface after depositing an organosilicon film with NTP treatment and to verify the surface energy before and after atmospheric air aging up to 30 days., Material and Methods: Sixteen lithium disilicate disks (10×3 mm) were prepared, and their surfaces were treated with a mixture of hexamethyldisiloxane and argon, followed by oxygen plasma treatment, both for 30 minutes. The lithium disilicate surface was characterized through scanning electron microscopy, energy-dispersive spectroscopy, and atomic force microscopy. Surface energy analysis was performed before (T0) and immediately after NTP treatment (T1) and after atmospheric air aging for 7 (T2), 15 (T3), and 30 days (T4). Data were submitted to analysis of variance followed by the Tukey HSD test (α=.05)., Results: Carbon, oxygen, and silicon were identified on the disilicate surface after NTP treatment, suggesting organosilicon film adhesion. Air aging did not modify the film morphology. At T1, the surface energy was significantly higher compared with other periods, and the water contact angle on the disilicate surface was reduced to 0 degrees. Similar surface energy was observed for T0, T2, T3, and T4., Conclusions: On the basis of the results of this in vitro study, NTP treatment can promote bonding to lithium disilicate surfaces because of its high surface wettability. However, after air aging, the wettability was not durable., (Copyright © 2016 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.)