Denture cleanser effect on resilient liners with distinct optical characteristics.

PURPOSE: To evaluate denture cleansing solutions regarding the surface roughness and color stability of two resilient liners with distinct optical characteristics used for the maximum recommended period of use. METHODS: The specimens of each resilient liner, transparent and white, were randomly distributed into groups (n= 15) of a daily 20-minute immersion simulation of 0.25%, 0.5% and 1% sodium hypochlorite (SH) and 4% acetic acid solutions. Surface roughness (Ra) and color stability (ΔE CIELab formula and NBS systems) were measured after 7, 14, 21, 30, 60, 90, 180, and 270 days. The factors of variations analyzed were material, solutions, and time of immersion. Statistical analysis used three-way ANOVA and Tukey tests (Ra), and repeated measure ANOVA (ΔE and NBS systems), P< 0.05. RESULTS: For Ra analysis, the variations occurred regardless of time and solution, as the white liner showed the greatest changes (P< 0.001). Regarding interactions between solution and time, in the period of 21 days until 270 days, Ra was equivalent for all solutions (P= 0.001). ΔE analysis showed a difference between solutions (P= 0.000) and interaction between time and solution (P= 0.000). For the transparent liner, the greatest changes were found for 1% SH after 60 days, however, at 270 days there was a color change equivalence with 0.5% SH, while 4% acetic acid solution showed intermediate values. For the white liner, 1% SH showed the highest color changes for all evaluated times, and the other evaluated solutions were similar after 270 days. For both resilient liners, 0.25% SH showed the smallest changes for the evaluated properties. CLINICAL SIGNIFICANCE: The changes found were dependent on the concentration of the solution used, as well as the length of exposure to the solution. In addition, the white resilient liner showed to be less susceptible to color changes. For both resilient liners, 0.25% sodium hypochlorite showed the least changes for the evaluated properties.

Effect of denture liners surface modification with Equisetum giganteum and Punica granatum on Candida albicans biofilm inhibition.

Aim: This study investigated the effect of denture liners surface modification with Equisetum giganteum (EG) and Punica granatum (PG) on Candida albicans biofilm inhibition supposing its usage as a sustained-release therapeutical delivery system for Candida-associated denture stomatitis. Materials & methods:C. albicans biofilm (SC5314 or ATCC 90028) was formed on soft liners superficially modified by a primer mixed to drugs at minimum inhibitory concentrations (0.100 g for EG and PG or 0.016 g for nystatin per ml of primer). After 24 h, 7 or 14 days, antibiofilm activity was evaluated by colony-forming unit counts. Results: Not all groups were equi-efficient to nystatin after 24 h and 7 days. After 14 days, EG and PG efficacies were not different from nystatin (almost 100% inhibition). Conclusion: The proposed protocol presents a promising option to allopathic drugs for Candida-associated denture stomatitis treatment.

Microbiological evaluation for antifungal activity of some metal oxides nanofillers incorporated into cold cured soft lining materials: clinical based study / Avaliação microbiológica da atividade antifúngica de algumas nanopartículas de óxidos metálicos incorporadas em materiais de revestimento macio curados a frio: estudo clínico

Objetivo: O objetivo do presente estudo foi avaliar a eficácia da adição de nanopartículas de óxido de zircônio (ZrO2), óxido de titânio (TiO2) e óxido de sílica (SiO2) a um material de revestimento macio curado a frio na adesão de Candida albicans (CA). Material e Método: Cinquenta e quatro pacientes foram selecionados e divididos em três grupos de acordo com a modificação do revestimento com nanopartículas de ZrO2, TiO2 e SiO2 (18 cada). Cada paciente recebeu prótese total maxilar com três cavidades, as cavidades foram revestidas com forro macio curado a frio modificado com diferentes concentrações (0%, 3% e 7%) de nanopartículas de óxido metálico. Nos dias 14 e 28, as trocas foram retiradas do local de realinhamento e imediatamente cultivadas para avaliação fúngica. O número de colônias foi contado, os dados coletados e explorados para normalidade usando o teste de Shapiro-Wilk e a transformação logarítmica da contagem de CA foi realizada. ANOVA para medidas repetidas e de uma via (one-way) foram usados, seguidos por teste de Tukey (HSD). O teste t independente foi usado para comparar as contagens de CA em diferentes períodos. Resultados: A adesão do CA foi significativamente diminuída pela adição de nanopartículas de ZrO2, TiO2 e SiO2 em comparação com o grupo controle, também a cobertura antifúngica aumentou com o aumento da concentração de nanopartículas (p <0,005). A maior contagem de CA foi identificada no grupo SiO2 seguido por ZrO2, enquanto TiO2apresentou a menor contagem de CA (p <0,001). Conclusão: Adição de diferentes nanopartículas; ZrO2, TiO2 e SiO2para revestimento macio curado a frio é um método eficaz para reduzir a adesão de CA (AU)

Objective: The aim of the current study was to evaluate the efficacy of addition of zirconium oxide (ZrO2), titanium oxide (TiO2), and silica oxide (SiO2) nanoparticles to cold-cured soft liner on adhesion of Candida albicans (CA). Material and Methods: Fifty-four patients had been selected and divided into three groups according to the modification of soft liner with ZrO2, TiO2, and SiO2 nanoparticles (18 each of). Each patient received maxillary complete denture having three cavities, the cavities were lined using cold cured soft liner modified with different concentration (0%, 3%, and 7%) of metal oxide nanoparticles. On days 14 and 28, swaps were taken out from relining site and immediately cultured for fungal evaluation. The number of colonies were counted, data collected and explored for normality using Shapiro-Wilk test, logarithmic transformation of CA count was performed. Repeated and one-way ANOVA were used followed by Tukey HSD. Independent-t test used to compare between CA counts at different periods. Results: The CA adhesion was significantly decreased by the addition of ZrO2, TiO2 and SiO2 nanoparticles in comparison with control group, also the antifungal coverage increased with nanoparticles concentration increased (P<0.005). The highest CA count was identified in group SiO2 followed by ZrO2, while TiO2 showed the lowest CA count (P <0.001). Conclusion: Addition of different nanoparticles; ZrO2, TiO2 and SiO2 to cold-cured soft liner is an effective method for reducing CA adhesion. (AU)

Influência de espessuras de fibromucosa e de material reembasador de próteses totais na distribuição de tensões sobre implantes cone morse durante fase de osseointegração: análise pelo método dos elementos finitos - 3D / Influence of fibromucosal thickness and reline material of complete dentures on stress distribution on cone morse implants during osseointegration phase: analysis by the finite element method - 3D

Durante o período de osseointegração de implantes em uma reabilitação oral com prótese do tipo protocolo ou overdenture, uma prótese total convencional provisória poderá ser utilizada e revestida com materiais reembasadores macios, os quais têm por objetivo reduzir o estresse para a interface ossoimplante. A avaliação mecânica de tal situação clínica é de extrema relevância, a fim de se estabelecer protocolos mais seguros durante esta fase inicial da implantodontia. O objetivo deste estudo foi realizar uma análise biomecânica pelo método dos elementos finitos 3D, da distribuição de tensões durante a fase provisória de reabilitação com implantes osseointegrados simulando uma situação clínica de protocolo/overdenture inferior sobre 4 implantes do tipo cone morse, na fase de cicatrização. Para este estudo foram confeccionados 6 modelos 3D, sob carregamento em 2 direções (vertical e oblíquo em relação ao plano oclusal), simulando osso tipo II, variando a altura do tecido gengival (2 mm e 3 mm) e a espessura do material reembasador (0 mm - sem material, 2 mm e 4 mm), sendo utilizado um cicatrizador compatível com a altura + 0,5 mm para cada situação gengival. A posição dos 4 implantes cone morse (UNITITE, UCM 3510N, SIN) foi sempre a mesma, nas posições perdidas dos dentes 46, 43, 33 e 36. Para a altura gengival de 2 mm foi utilizado cicatrizador de 2,5 mm de altura (UNITITE, CIMU 4525, SIN) e para a altura gengival de 3 mm, o cicatrizador de 3,5 mm de altura (UNITITE, CIMU 4535, SIN). Os modelos utilizados foram: (G2C2,5-SR) altura gengival de 2mm, cicatrizador de 2,5mm, sem material reembasador; (G2C2,5-R2) altura gengival de 2mm, cicatrizador de 2,5mm, com soft rreembasador de 2mm; (G2C2,5-R4) altura gengival de 2mm, cicatrizador de 2,5mm, com material reembasador de 4mm; (G3C3,5-SR) altura gengival de 3mm, cicatrizador de 3,5mm, sem material reembasador; (G3C3,5-R2) altura gengival de 3mm, cicatrizador de 3,5mm, e reembasador de 2mm e (G3C3,5-R4) altura gengival de 3mm, cicatrizador de 3,5mm e soft reembasador de 4mm. A metodologia para modelagem se baseou em um escaneamento de superfície de uma prótese total inferior montada, sob um modelo inferior padrão, e de seu modelo de assentamento. As geometrias dos implantes (CM 3,5x10mm) e de seus cicatrizadores foram obtidas por simplificação do desenho dos mesmos no programa SolidWorks e no programa Rhinoceros 3D. O software utilizado para análise foi o ANSYS 17.0. A visualização dos resultados foi qualitativa através de mapas de deslocamento, von Mises e tensão máxima principal. As regiões com maiores deslocamentos foram as dos implantes mais anteriores (#33 e #43), sendo os do modelo 6 submetidos a forças verticais os que apresentaram maiores deslocamentos, próximos a 0,05 mm. A força oblíqua, de forma geral, tendeu a sobrecarregar mais os implantes do lado onde as cargas foram aplicadas. No tecido ósseo foi possível observar que o osso cortical se mostrou com mais concentração de tensão de tração que o osso trabecular. A utilização do material reembasador gerou menores tensões transmitidas para o tecido gengival, concentrando estas tensões principalmente no material reembasador. A não utilização de material reembasador aumenta as concentrações de tensões nos implantes/cicatrizadores, independentemente de sua espessura ou da espessura gengival. Concluiu-se que o uso de reembasador soft diminuiu as tensões nos implantes/cicatrizadores e tecido gengival; o aumento da espessura do material reembasador não influenciou na diminuição das tensões aos tecidos de suporte e tecidos gengivais mais espessos foram favoráveis em diminuir as tensões transmitidas ao tecido ósseo, mas concentram mais tensões nos implantes/cicatrizadores(AU)

During the period of osseointegration of implants in an oral rehabilitation with a protocol or overdenturetype prosthesis, a conventional temporary complete denture can be used and coated with soft reline materials, which aim to reduce the stress to the bone-implant interface. The mechanical assessment of such a clinical situation is extremely relevant in order to establish safer protocols during this initial phase of implantology. The objective of this study was to perform a biomechanical analysis by the 3D finite element method, of the stress distribution during the provisional phase of rehabilitation with osseointegrated implants simulating a clinical situation of protocol/lower overdenture on 4 cone morse implants, in the healing phase. For this study, 6 3D models were made, under loading in 2 directions (vertical and oblique in relation to the occlusal plane), simulating type II bone, varying the height of the gingival tissue (2 mm and 3 mm) and the thickness of the reline material (0 mm - without material, 2 mm and 4 mm), using a healer compatible with the height + 0.5 mm for each gingival situation. The position of the 4 cone morse implants (UNITITE, UCM 3510N, SIN) was always the same, in the missing positions of teeth 46, 43, 33 and 36. For the 2 mm gingival height, a 2.5 mm high healer was used. (UNITITE, CIMU 4525, SIN) and for a gingival height of 3 mm, the healer with a height of 3.5 mm (UNITITE, CIMU 4535, SIN). The models used were: (G2H2,5-WS) 2mm gingival height, 2.5mm healing, without soft material; (G2H2,5-S2) 2mm gingival height, 2.5mm healing, with 2mm reline; (G2H2,5-S4) 2mm gingival height, 2.5mm healing, with 4mm reline; (G3H3,5-WS) gingival height of 3mm, healing of 3.5mm, without soft material; (G3H3,5-S2) 3mm gingival height, 3.5mm healing, and 2mm reline and (G3H3,5-S4) gingival height of 3mm, healing of 3.5mm and reliner of 4mm. The methodology for modeling was based on a surface scan of a complete lower denture assembled, under a standard lower model, and its seating model. The geometries of the implants (CM 3.5x10mm) and their healers were obtained by simplifying their design in the SolidWorks program and in the Rhinoceros 3D program. The software used for analysis was ANSYS 17.0. The visualization of the results was qualitative through displacement maps, von Mises and maximum principal stress. The regions with the greatest displacements were those of the most anterior implants (#33 and #43), and those of model 6 submitted to vertical forces presented the greatest displacements, close to 0.05 mm. The oblique force, in general, tended to place more stress on the implants on the side where the loads were applied. In the bone tissue, it was possible to observe that the cortical bone showed a higher concentration of tensile stress than the trabecular bone. The use of soft material generated lower tensions transmitted to the gingival tissue, concentrating these tensions mainly in the soft material. The non-use of soft material increases stress concentrations on implants/healers, regardless of their thickness or gingival thickness. It was concluded that the use of a soft reliner reduced the stresses on the implants/healers and gingival tissue; the increase in the thickness of the reline material did not influence the reduction of tensions to the supporting tissues and thicker gingival tissues were favorable in reducing the tensions transmitted to the bone tissue, but concentrated more tensions in the implants/healing agentes(AU)

Surface morphology and in vitro leachability of soft liners modified by the incorporation of antifungals for denture stomatitis treatment.

OBJECTIVE: To evaluate the surface morphology and in vitro leachability of temporary soft linings modified by the incorporation of antifungals in minimum inhibitory concentrations (MIC) for Candida albicans biofilm. METHODOLOGY: Specimens of soft lining materials Softone and Trusoft were made without (control) or with the addition of nystatin (Ny), miconazole (Mc), ketoconazole (Ke), chlorhexidine diacetate (Chx), or itraconazole (It) at their MIC for C. albicans biofilm. The surface analyses were performed using Confocal laser scanning microscopy after 24 h, 7 days, or 14 days of immersion in distilled water at 37ºC. In vitro leachability of Chx or Ny from the modified materials was also measured using Ultraviolet visible spectroscopy for up to 14 days of immersion in distilled water at 37ºC. Data (µg/mL) were submitted to ANOVA 1-factor/Bonferroni (α=0.05). RESULTS: Softone had a more irregular surface than Trusoft. Morphological changes were noted in both materials with increasing immersion time, particularly, in those containing drugs. Groups containing Chx and It presented extremely porous and irregular surfaces. Both materials had biexponential release kinetics. Softone leached a higher concentration of the antifungals than Trusoft (p=0.004), and chlorhexidine was released at a higher concentration than nystatin (p<0.001). CONCLUSIONS: The surface of the soft lining materials changed more significantly with the addition of Chx or It. Softone released a higher concentration of drugs than Trusoft did, guiding the future treatment of denture stomatitis.

Avaliação do comportamento antimicrobiano de um glaze e reembasador modificados por nanopartículas de sílica com prata / Avaliação do comportamento antimicrobiano de um glaze e reembasador modificados por nanopartículas de sílica com prata

O objetivo do trabalho foi avaliar a ação antimicrobiana de um glaze e um reembasador macio com nanopartículas de sílica revestidas por prata. Para isso, foi realizada a síntese e caracterização de nanopartículas de sílica recobertas por prata, que foram avaliadas através do teste de concentração inibitória mínima (CIM) para C. albicans. Após isso, foram confeccionadas amostras e divididas em 6 grupos (n=12): CG: glaze e reembasador macio; CR: reembasador macio; G1: glaze com nanopartículas a 1% e reembasador macio; G2: glaze com nanopartículas a 2,5% e reembasador macio; R1: reembasador macio com nanopartículas a 1%; R2: reembasador macio com nanopartículas a 2,5%. Foram realizados testes de ângulo de contato e efeito anti-biofilme nas amostras. De acordo com o resultado da CIM, houve redução das contagens de fungos após adição de ambas as nanopartículas, não funcionalizada (a 1000 µg/mL) e funcionalizada (a 2000 µg/mL). Para o ângulo de contato, houve uma redução significativa da molhabilidade nos grupos G2 (p=0,001) e R2 (p=0,000). Para o ensaio de biofilme, houve uma redução de 64% na contagem de UFC/espécime para o grupo G1, porém, esta diferença não foi estatisticamente significante (p=0,244). Já para o reembasador, houve um aumento não significativo (p=0,264) de UFC/espécime com a agregação das nanopartículas. Pode-se concluir que houve redução do crescimento fúngico para o teste de CIM nos poços que receberam as nanopartículas. Houve alteração significativa da energia de superfície e molhabilidade nos grupos G2 e R2. Houve uma redução de 64% de UFC/espécime para o grupo G1 quando comparada ao CG, não sendo estatisticamente significativa. Assim, o desenvolvimento de um glaze, nas condições observadas, pode ter potencial antifúngico promissor.

The study aimed to evaluate the antimicrobial action of glaze and soft reline with silver-coated silica nanoparticles. So, silver-coated silica nanoparticles were synthesized and characterized. The test of minimum inhibitory concentration (MIC) for C. albicans evaluated the antimicrobial potential of the nanoparticle. After that, samples were made and divided into six groups (n = 12): CG: glaze and soft reline; CR: soft reline; G1: glaze with 1% nanoparticles and soft reline; G2: glaze with 2.5% nanoparticles and soft reline; R1: soft reline with 1% nanoparticles; R2: soft reline with 2.5% nanoparticles. The contact angle test evaluated the wettability of the samples' surface. The anti-biofilm test evaluated the fungal growth. According to the MIC result, there was a reduction in fungal counts after the addition of both nanoparticles, non-functionalized (at 1000 µg / mL) and functionalized (at 2000 µg / mL). In the contact angle test, the wettability significantly decreased for the group G2 (p = 0.001) and group R2 (p = 0.000). In the anti-biofilm test, there was a reduction of 64% of CFU/specimen count in group G1. As for the reline, there was a non-significant increase (p = 0.264) of CFU/specimen with the aggregation of the nanoparticles. Overall, there was a reduction in fungal growth for the MIC test in the microplates that received the nanoparticles. There was a reduction of 64% of CFU/specimen count in group G1 compared to the CG, which not statistically significant. Thus, the development of a glaze, under the conditions observed, may have promising antifungal potential.

Estimation of the autoclave and different surface treatments on microleakage between soft liner and heat-cured acrylic / Estimativa da autoclavagem e diferentes tratamentos de superfície na microinfiltração entre o soft liner e o acrílico termopolimerizável

Objective: The present study was oriented to estimate the effect of different surface treatments on the microleakage between the soft liner and acrylic with and without the use of autoclave as disinfection method. Material and Methods: Sixty samples were split into two groups: the autoclaved groups and non-autoclaved groups. Each one subdivided into three groups: first one without any treatments as a control group; in the second group surface of the samples were treated with CO2 laser (10.6 nm wavelength for 15 seconds), and in the third group the surface was treated with sandblasting (250 µm Al2O3). All the samples exposed to thermocycling, then the microleakage test was evaluated by gauging dye penetration depth between the soft liner and acrylic disc using a digital microscope. Data analyzed statistically by One-way ANOVA and Tukey's post-hoc tests. In addition, t-test was used for comparison between two groups (P-value ≤ 0.05). Results: The maximum mean values for the microleakage were observed in the untreated group (control) followed by the group treated by CO2 laser and the lowest mean value of microleakage was related to the third group for both non-autoclaved and autoclaved groups with significant differences among them. In addition, depending on the use of autoclave, there was non-significant in all studied groups. Conclusions: There was a decrease in the microleakage when the surface treated with CO2laser and sandblast. The use of autoclave did not badly change the microleakage between the soft liner and denture base. (AU)

Objetivo: O presente estudo teve como objetivo estimar o efeito de diferentes tratamentos de superfície na microinfiltração entre o soft liner e o acrílico usando ou não a autoclve como método de desinfecção. Material e Métodos: Sessenta amostras foram divididas em dois grupos: grupo com uso da autoclave e grupo sem uso da autoclave. Cada um subdivide em três grupos: o primeiro sem nenhum tratamento como grupo controle; no segundo grupo, a superfície das amostras foi tratada com laser de CO2 (comprimento de onda de 10,6 nm por 15 segundos) e, no terceiro grupo, a superfície foi tratada com jateamento (250 µm Al2O3). Todas as amostras foram expostas à termociclagem, em seguida o teste de microinfiltração foi realizado medindo-se a profundidade de penetração do corante entre o soft liner e o disco de acrílico em microscópio digital. Os dados foram analisados estatisticamente por One-way ANOVA e testes post-hoc de Tukey. Além disso, o teste t foi usado para comparação entre dois grupos (P-valor ≤ 0,05). Resultados: Os valores médios máximos de microinfiltração foram observados no grupo não tratado (controle) seguido pelo grupo tratado com laser de CO2 e o valor médio mínimo de microinfiltração foi relacionado ao terceiro grupo para ambos os grupos não autoclavado e autoclavado com diferenças significativas entre eles. Além disso, dependendo do uso de autoclave, não houve significância em todos os grupos estudados. Conclusão: Houve diminuição da microinfiltração quando a superfície foi tratada com laser de CO2e jateamento. O uso de autoclave não alterou a microinfiltração entre o soft liner e a base da prótese (AU)

Antimicrobial and protective effects of non-thermal plasma treatments on the performance of a resinous liner.

OBJECTIVE: Overcoming substantial shortcomings of soft liners as physico-chemical changes and liner-biofilm-related infections remains a challenge in the rehabilitation treatment. In this study, protective non-thermal plasma (NTP) treatments were developed on the soft liner surface to improve its surface and physico-chemical properties and to reduce fungal colonization after biofilm inhibition challenge. METHODS: Resinous liner specimens (Coe-Soft) were prepared and distributed in 3 groups according to the surface treatments: (1) untreated (control); (2) treated with sulfur hexafluoride-based NTP (SF6); and (3) treated with hexamethyldisiloxane-based NTP (HMDSO). To test the NTP stability and their protective and antimicrobial effect on the liner surface over time, the morphology, chemical composition, roughness, water contact angle, shore A hardness, sorption and solubility were evaluated before and after the specimens were exposed to dual-species biofilm of Candida albicans and Streptococcus oralis for 14 days. Colony forming units and biofilm structure were assessed. Data were submitted to ANOVA and Tukey tests (α = 0.05). RESULTS: Both treatments modified the surface morphology, increased hydrophobicity and roughness of the liner, and were effective to reduce C. albicans adhesion without affecting the commensal health-associated S. oralis. HMDSO presented chemical stability and lower hardness in both periods, whereas SF6 exhibited higher initial hardness than control and the highest sorption; contrarily, similar solubility was noted for all groups. CONCLUSION: HMDSO-based film showed improved physico-chemical properties and inhibited C. albicans biofilm. Thus, it has potential for use to control candida-related stomatitis and improve liner's stability even after being exposed to biofilm inhibition challenge.

Surface morphology and in vitro leachability of soft liners modified by the incorporation of antifungals for denture stomatitis treatment

Abstract Objective: To evaluate the surface morphology and in vitro leachability of temporary soft linings modified by the incorporation of antifungals in minimum inhibitory concentrations (MIC) for Candida albicans biofilm. Methodology:Specimens of soft lining materials Softone and Trusoft were made without (control) or with the addition of nystatin (Ny), miconazole (Mc), ketoconazole (Ke), chlorhexidine diacetate (Chx), or itraconazole (It) at their MIC for C. albicans biofilm. The surface analyses were performed using Confocal laser scanning microscopy after 24 h, 7 days, or 14 days of immersion in distilled water at 37ºC. In vitro leachability of Chx or Ny from the modified materials was also measured using Ultraviolet visible spectroscopy for up to 14 days of immersion in distilled water at 37ºC. Data (µg/mL) were submitted to ANOVA 1-factor/Bonferroni (α=0.05). Results: Softone had a more irregular surface than Trusoft. Morphological changes were noted in both materials with increasing immersion time, particularly, in those containing drugs. Groups containing Chx and It presented extremely porous and irregular surfaces. Both materials had biexponential release kinetics. Softone leached a higher concentration of the antifungals than Trusoft (p=0.004), and chlorhexidine was released at a higher concentration than nystatin (p<0.001). Conclusions: The surface of the soft lining materials changed more significantly with the addition of Chx or It. Softone released a higher concentration of drugs than Trusoft did, guiding the future treatment of denture stomatitis.

Influence of AgVO3 incorporation on antimicrobial properties, hardness, roughness and adhesion of a soft denture liner.

The objective of this in vitro study was to investigate the effect of nanostructured silver vanadate decorated with silver nanoparticles (AgVO3) on antimicrobial activity, hardness, roughness, and adhesion of a soft denture liner. The antimicrobial efficacy of the Trusoft (Boswoth) liner incorporated with different concentrations of AgVO3 against Enterococcus faecalis, Pseudomonas aeruginosa, Candida albicans, and Staphyloccocus aureus (n = 5) was evaluated by the agar diffusion method. Roughness, hardness, and adhesion properties were also evaluated. The data were analyzed by analysis of variance (ANOVA) and Tukey's multiple comparison test with significance at the p < 0.05 level. At concentrations of 1 and 2.5%, AgVO3 incorporation was effective only against E. faecalis, and at 5 and 10%, against E. faecalis, P. aeruginosa, and C. albicans. None of the concentrations was effective against S. aureus. A decrease in hardness was found for the 1, 2.5, and 10% AgVO3 concentrations (p < 0.001) and at 5%, hardness was not affected. None of the concentrations affected the roughness of the material. A significant increase in tensile values was observed between the liner and heat-curing acrylic resin for 2.5% (p < 0.001) and 10% (p = 0.042) concentrations. AgVO3 incorporation to a soft denture liner promoted antimicrobial activity against E. faecalis, P. aeruginosa, and C. albicans without affecting roughness, maintaining the hardness properties recommended for soft and extra soft liners, and improving the adhesion between the liner and the acrylic resin used for dentures.

Antibiofilm Activity of an Experimental Ricinus Communis Dentifrice on Soft Denture Liners.

The disadvantage of liners materials is the difficulty of biofilm control. It was compared an experimental dentifrice contained Ricinus communis, with commercials dentifrices as antibiofilm activity against microorganisms on denture liner. Six hundred specimens were distributed in 5 groups (n=18/ microorganism): water; experimental dentifrice; specific dentifrice for denture and two conventional dentifrices against C. albicans; C. glabrata; S. mutans; S. aureus; E. coli. Each group had a negative (n=5; without contamination) and positive control (n=15/ microorganism; without cleaning). The antibiofilm activity was evaluated by the method of biofilm formation in triplicate. The specimens were contaminated in a standard way and incubated. After that, manual brushing was performed (60 s), washed with PBS, immersed in liquid culture medium for resuspension and sowing in solid medium. The results (mean of triplicates) were expressed in CFU/mL. The data was submitted to Shapiro-Wilk, ANOVA and Tukey test (p<0.05). The specific dentifrice (1.27±1.20) was the most effective against S. mutans, followed by conventional (Trihydral, 3.13±0.88; Colgate, 2.16±2.02) and experimental (3.81±1.37) dentifrices, which were similar to each other (p=0.008). All of them were different from water (4.79±1.42). The specific (0.21±0.21) and experimental (0.36±0.25) dentifrices were similar against S. aureus, with a higher mean of CFU when compared to conventional (Colgate, 0.06±0.13), which was more efficient (p=0.000). For C. albicans, C. glabrata and E. coli, all dentifrices were similar to water (p=0.186). It was concluded, that the experimental dentifrice was effective against S. aureus and had not efficacy against Candida spp.; S. mutans; E. coli, as occurred with the commercials dentifrices.

Antibiofilm activity of an experimental ricinus communis dentifrice on soft denture liners

Abstract The disadvantage of liners materials is the difficulty of biofilm control. It was compared an experimental dentifrice contained Ricinus communis, with commercials dentifrices as antibiofilm activity against microorganisms on denture liner. Six hundred specimens were distributed in 5 groups (n=18/ microorganism): water; experimental dentifrice; specific dentifrice for denture and two conventional dentifrices against C. albicans; C. glabrata; S. mutans; S. aureus; E. coli. Each group had a negative (n=5; without contamination) and positive control (n=15/ microorganism; without cleaning). The antibiofilm activity was evaluated by the method of biofilm formation in triplicate. The specimens were contaminated in a standard way and incubated. After that, manual brushing was performed (60 s), washed with PBS, immersed in liquid culture medium for resuspension and sowing in solid medium. The results (mean of triplicates) were expressed in CFU/mL. The data was submitted to Shapiro-Wilk, ANOVA and Tukey test (p<0.05). The specific dentifrice (1.27±1.20) was the most effective against S. mutans, followed by conventional (Trihydral, 3.13±0.88; Colgate, 2.16±2.02) and experimental (3.81±1.37) dentifrices, which were similar to each other (p=0.008). All of them were different from water (4.79±1.42). The specific (0.21±0.21) and experimental (0.36±0.25) dentifrices were similar against S. aureus, with a higher mean of CFU when compared to conventional (Colgate, 0.06±0.13), which was more efficient (p=0.000). For C. albicans, C. glabrata and E. coli, all dentifrices were similar to water (p=0.186). It was concluded, that the experimental dentifrice was effective against S. aureus and had not efficacy against Candida spp.; S. mutans; E. coli, as occurred with the commercials dentifrices.

Resumo A desvantagem dos materiais resilientes é a dificuldade de controle do biofilme. Este estudo comparou um dentífrico experimental contendo Ricinus communis, com dentifrícios comerciais quanto atividade contra biofilme formado em reembasador de próteses totais. Seiscentos espécimes foram distribuídos em 5 grupos (n=18/microrganismo): água; dentifrício experimental; dentifrício específico para próteses totais e dois convencionais; contra C. albicans; C. glabrata; S. mutans; S. aureus; E. coli. Cada grupo teve um controle negativo (n=5; sem contaminação) e um positivo (n=15/ microrganismo; sem higienização). A atividade contra biofilme foi avaliada pelo método de formação do biofilme, em triplicata. Os espécimes foram contaminados, padronizadamente, e incubados. Posteriormente, foi realizada escovação manual (60 s), lavagem em PBS, imersão em meio de cultura líquido para ressuspensão e semeadura em meio sólido. Os resultados (média das triplicatas) foram expressos em UFC/mL. Os dados foram submetidos aos testes Shapiro-Wilk, ANOVA e Tukey (p<0,05). O dentifrício específico (1,27±1,20) foi o mais eficaz contra S. mutans, seguido dos convencionais (Trihydral, 3,13±0,88; Colgate, 2,16±2,02) e experimental (3,81±1,37), que foram semelhantes entre si (p=0,008). Todos eles foram diferentes da água (4,79±1,42). O dentifrício específico (0,21±0,21) e o experimental (0,36±0,25) foram semelhantes contra S. aureus, com maiores médias de UFC quando comparado ao convencional (Colgate, 0,06±0,13), que foi mais eficiente (p=0,000). Para C. albicans, C. glabrata e E.coli, todos os dentifrícios foram similares à água (p=0,186). Conclui-se que o dentifrício experimental foi efetivo somente contra S. aureus e não foi eficiente perante Candida spp.; S. mutans; E. coli, como ocorrido com os dentifrícios comerciais.

Denture Liners: A Systematic Review Relative to Adhesion and Mechanical Properties.

PURPOSE: The objective of this systematic review is to compare results concerning the properties of adhesion, roughness, and hardness of dental liners obtained in the last ten years. METHODS: Searches on the databases LILACS, PubMed/Medline, Web of Science, and Cochrane Database of Systematic Reviews were supplemented with manual searches conducted between February and April of 2018. The inclusion criteria included experimental in vitro and in vivo, clinical, and laboratory studies on resilient and/or hard liners, assessment of hardness, roughness, and/or adhesion to the denture base, and physical/mechanical changes resulting from the disinfection process and changes in liners' composition or application. RESULTS: A total of 406 articles were identified and, from those, 44 are discussed. Twenty-four studies examined the bond strength, 13 surface roughness, and 19 the hardness. Of these 44 studies, 12 evaluated more than one property. Different substances were used in the attempt to improve adhesion. Considering roughness and hardness, the benefits of sealants have been tested, and the changes resulting from antimicrobial agents' incorporation have been assessed. CONCLUSION: Adhesion to the prosthesis base is improved with surface treatments. Rough surfaces and changes in hardness compromise the material's serviceability.

In vivo biocompatibility of an interim denture resilient liner containing antifungal drugs.

STATEMENT OF PROBLEM: Antifungal agents incorporated into interim denture resilient liners have been suggested as an adjunct treatment for denture stomatitis (DS). However, before applying this protocol to humans, biocompatibility analysis of such drugs in animal models is required. PURPOSE: The purpose of this animal study was to evaluate the in vivo biocompatibility of an interim resilient liner modified with minimum inhibitory concentrations (MICs) of antifungal drugs for Candida albicans biofilm. MATERIAL AND METHODS: Sixty Wistar rats were divided into 6 groups (n=5): PC=positive control/no protocol; IOD (intraoral device)=rats using an acrylic resin palatal device (PD); Tru=rats using a PD relined with Trusoft; and Ny (nystatin), Chx (chlorhexidine diacetate), and Ke (ketoconazole) groups=rats using a PD relined with Trusoft + drug MICs. The rats were sacrificed at 7 or 14 days of trial. Histopathological qualitative analysis was performed by comparing photomicrographs of histological sections of the intermolar region. Morphological changes in the epithelium and keratin were quantitatively analyzed by computerized planimetry, and data were analyzed by using 2-way ANOVA and the Tukey HSD test (α=.05). RESULTS: Quantitative analysis showed that only PD containing Ke significantly decreased the thickness and area of the keratin compared with the other groups (P<.001), which showed no differences between each other (P>.05). These results agreed with those of qualitative analysis. CONCLUSIONS: Incorporation of MICs of Ny and Chx in Trusoft did not induce histopathological changes in the rat palatal mucosa, suggesting the in vivo biocompatibility of this DS treatment.

Determining acceptable limits for water sorption and solubility of interim denture resilient liners.

STATEMENT OF PROBLEM: Specifications for determining acceptable limits of water sorption (WS) and solubility for interim denture resilient liners are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the WS and solubility of interim resilient materials throughout their lifespans. MATERIAL AND METHODS: Specimens (n=10) of 7 tissue conditioners, Coe-Comfort (CC), Softone (ST), Rite-Line (RL), Dura Conditioner (DC), Hydrocast (HC), Dentusoft (DS), and Visco-gel (VG) and 2 interim resilient liners, Trusoft (TS) and Coe-Soft (CS), were submitted to desorption until weight stabilization. Next, they were immersed in distilled water at 37°C for 3, 5, 7, or 14 days and then weighed, dried, and reweighed. Data (%) were analyzed using 2-way ANOVA and the Tukey honestly significant difference (HSD) test (α=.05). RESULTS: VG demonstrated the highest WS (12.06 ±0.93%-16.62 ±0.87%) and solubility (20.30 ±4.26%-23.59 ±2.24%; P<.05) percentages. Low WS values were presented by CC (2.23 ±0.53%-2.99 ±0.49%; P<.05). The WS showed no significant changes for CC, CS, and TS over 14 days (P>.05). SL presented intermediate solubility values (4.09 ±1.60%-8.80 ±1.15%), and the other materials showed values lower than 3.35 ±0.70%. CC, DC, DS, HC, RL, TS, and CS showed no changes in solubility throughout the 14-day trial. CONCLUSIONS: Over the lifespan of a tissue conditioner (7 days), CC, RL, DC, HC, DS, CS, and TS presented suitable in vitro performance. Among the tested materials, CC, CS, and TS were considered best suited for denture relining for up to 14 days.

In Vitro Evaluation of Resilient Liner after Brushing with Conventional and Experimental Ricinus communis-Based Dentifrices.

PURPOSE: To evaluate the effect of experimental (Ricinus communis) and commercial dentifrices used for denture cleaning on abrasiveness (gravimetric method; roughness), hardness, and color stability of a resilient relining material. MATERIALS AND METHODS: Sixty circular (15 × 3 mm) specimens were distributed into four groups: C (control; brushing with water); CO (brushing with Colgate - for natural teeth); CB (brushing with Corega Brite - for complete dentures); RC (brushing with experimental dentifrice). Brushing was performed in a toothbrushing machine with a soft brush and a dentifrice suspension for 50 minutes, calculated to correspond to 1 year of regular brushing. Variables were measured initially and after the trial period. For the gravimetric method, the difference in mass was considered. The surface roughness was measured by a rugosimeter, and the hardness test was performed by a Shore A durometer. Color changes (ΔE; CIE L*a*b* and NBS systems) were measured by a portable spectrophotometer. Results were analyzed by ANOVA/Tukey's test (α = 0.05). RESULTS: The largest mass variation (µg; p < 0.0001) occurred in C (-6.21 ± 3.18). Concerning roughness, CB (0.26 ± 0.04) showed the lowest value, followed by RC (0.29 ± 0.08) and CO (0.34 ± 0.24) (p < 0.0001). Group C produced the greatest surface roughness (0.72 ± 0.25). Hardness values decreased after brushing with water (p = 0.014). No significant differences were found among RC (50.31 ± 1.03), CO (49.11 ± 1.31), CB (49.17 ± 1.23), and C (48.02 ± 1.26). Color stability was similar in all groups (p = 0.135; C: 2.3 ± 0.77; CO: 2.6 ± 0.54; CB: 2.2 ± 0.44; RC: 2.9 ± 1.56). CONCLUSIONS: The use of experimental dentifrice could be indicated, as it showed similar results to the specific dentifrice, keeping the resilient material properties within acceptable values.

Cytotoxic potential of denture base and reline acrylic resins after immersion in disinfectant solutions.

STATEMENT OF PROBLEM: The daily immersion of dentures in disinfectant solutions can cause the incorporation of toxic substances in the acrylic resins, and studies evaluating the cumulative effect of disinfectant solutions on cell culture are lacking. PURPOSE: The purpose of this in vitro study was to evaluate the cytotoxic potential of cell cultures of denture base and reline acrylic resins after immersion in disinfectant solutions. MATERIAL AND METHODS: Disk-shaped specimens (14×1.2 mm) were obtained and divided into groups (n=9) according to the disinfectant solutions (distilled water [control], 2% chlorhexidine digluconate, 3.8% sodium perborate, 0.5% sodium hypochlorite, and apple vinegar) and to the storage period (0, 1, 3, and 6 months). Solutions were changed daily. After the different storage periods, specimens were immersed in culture medium for 24 hours, and extracts were obtained. Human keratinocytes were cultivated, and the cellular metabolism was evaluated by using Alamar Blue. Data were submitted to 3-way analysis of variance and Games-Howell post hoc tests (α=.05). RESULTS: Both of the acrylic resins tested showed similar biocompatibility properties after immersion in different solutions (P=.400). Immersion in distilled water, 3.8% sodium perborate, and 0.5% sodium hypochlorite did not affect the cellular metabolism of the keratinocytes (P>.05), regardless of the immersion period and the type of acrylic resin (P>.05). Immersion in 2% chlorhexidine digluconate or apple vinegar resulted in high cytotoxicity over time, until the third month (P<.05), after which no changes were observed (P>.05). CONCLUSIONS: The type of acrylic resin (base or reline) had no significant effect on the viability of cells. Vinegar and chlorhexidine digluconate solutions increased in cytotoxic effect over time, and were strongly cytotoxic after 6 months of immersion. Sodium perborate and sodium hypochlorite were noncytotoxic in all periods of time tested.

Effect of surface characteristics of soft liners and tissue conditioners and saliva on the adhesion and biofilm formation.

PURPOSE: To investigate the influence of surface characteristics and saliva on the adhesion and biofilm formation of Candida glabrata and methicillin-resistant Staphylococcus aureus (MRSA) to soft liners and tissue conditioners. METHODS: For each material (Ufi Gel P - UG; Sofreliner S - SS; Trusoft - TR; Coe Comfort - CC; Softone - ST), specimens were prepared and roughness (Ra), hydrophobicity (water contact angles-WCA) and surface free energy (SFE) were measured. Surface morphology was also analyzed using scanning electron microscopy (SEM). Specimens were incubated in C. glabrata or MRSA suspensions for 90 minutes (adhesion) or 48 hours (biofilm). The absorbance (AB) was measured by XTT assay. Experiments were performed using specimens that were either uncoated or had been coated with saliva. Data were analyzed using one- or two-way ANOVAs, followed by Tukey's test (α= 0.05). RESULTS: TR exhibited the highest Ra and UG the lowest. SEM images also showed that UG and SS had smooth surfaces, while TR presented several irregularities and pores. In the absence of saliva, UG and SS presented higher WCA and lower SFE than the other materials. XTT results showed that, in the C. glabrata adhesion assay, the AB value was higher for TR followed by UG > CC> SS> ST. For the biofilm formation of C. glabrata, AB values were in the following order TR > CC = UG > ST = SS. In the adhesion assay, AB values obtained for MRSA were TR > UG = CC > ST > SS and for the biofilm formation were TR > ST > CC > UG > SS. Saliva decreased the WCA and increased the SFE for all materials. In general, the presence of saliva decreased the adhesion and biofilm formation of both microorganisms to the acrylic-based material (TR) and tissue conditioners (CC and ST), and increased for the silicone-based soft liners (UH and SS). Surface characteristics and the influence of saliva varied among materials. Roughness seemed to favor C. glabrata and MRSA adhesion and biofilm formation. CLINICAL SIGNIFICANCE: The presence of microorganisms on denture liners can irritate the oral tissues and contribute to systemic diseases. Colonization with more tolerant microorganisms such as C. glabrata and MRSA may expose patients to a greater risk of infection, mainly in immunocompromised hosts, such as aged individuals after treatment of oral cancer. For this, it is important to investigate the surface characteristics of soft liners and tissue conditioners, as well as saliva, and their influence on the adhesion and biofilm formation of C. glabrata and methicillin-resistant Staphylococcus aureus.

Satisfação e qualidade de vida em pacientes desdentados após reembasamento com material resiliente / Installation of implant-supported provisional prosthesis: case report

O objetivo desse trabalho foi avaliar a satisfação e a qualidade de vida de pacientes desdentados que tiveram suas próteses totais mandibulares reembasadas com material resiliente (Ufi Gel SC, VOCO, Alemanha). Foram selecionados 20 pacientes desdentados divididos aleatoriamente nos grupos de reembasamento direto ou indireto (n=10). Foram aplicados dois questionários, o OHIP Edent para avaliar a qualidade de vida e um questionário desenvolvido para verificar a satisfação dos pacientes com o uso do reembasador. Os testes clínicos foram realizados em quatro fases durante o tratamento: inicialmente com as próteses totais sem intervenção, 30, 60 e 90 dias após o reembasamento. A análise de variância ANOVA demonstrou que houve uma diferença estatisticamente significante para o fator tempo tanto para a qualidade de vida como para a satisfação (p d" 0,05). Observamos que a qualidade de visa e a satisfação aumentaram após o reembasamento, mas não houve diferença entre os métodos de polimerização testados. O método de polimerização direto é mais simples, menos demorado e menos oneroso para o paciente. Portanto, se não houver diferença entre os métodos de polimerização a longo prazo, não há porque submeter o paciente ao reembasamento indireto(AU)

The aim of this paper was to assess the quality of life and satisfaction for edentulous individuals who had their complete dentures relined with a soft liner material (Ufi Gel SC, VOCO, Germany). A total of 20 patients were selected and divided into two experimental groups, one for a chairside procedure and one for a laboratorial reline (n=10). Two questionnaires were used, the OHIP Edent and a satisfaction form to assess information on the reline material. The tests were performed initially and at 30, 60 and 90 days after the reline. The analysis of variance ANOVA presented a difference for the period evaluation, the quality of life improved after the procedure, but there was no difference between the polymerization methods. The chairside procedure is more simple, faster and more practical for both, professionals and patients. Therefore, if there are no difference in long term results, there is no reason to the patient undergo the laboratorial reline process(AU)

Effect of Incorporation of Antifungal Agents on the Ultimate Tensile Strength of Temporary Soft Denture Liners.

PURPOSE: To investigate the ultimate tensile strength of temporary soft denture liners modified by minimum inhibitory concentrations (MICs) of antifungal agents for Candida albicans biofilm (SC5314) determined in previous microbiological research. MATERIALS AND METHODS: Dumbbell-shaped specimens (n = 7) with a central cross-sectional area of 6 × 3 × 33 mm were produced by Softone and Trusoft, without (control) or with incorporation of drugs in powder form at MICs for C. albicans biofilm (per g of material powder): nystatin (0.032 g), chlorhexidine diacetate (0.064 g), ketoconazole (0.128 g), miconazole (0.256 g), and itraconazole (0.256 g). After plasticization, specimens were immersed in distilled water at 37°C for 24 hours, 7 or 14 days, and then tested in tension in a universal testing machine at 40 mm/min. Data of tensile strength (MPa) and elongation percentage (%) were submitted to 3-way ANOVA and Tukey's test (α = 0.05). RESULTS: At the end of 14 days, the tensile strength for both materials was significantly lower in the groups modified by miconazole and itraconazole compared to the other groups (p < 0.0001), which showed no significant difference between them (p > 0.05). After 7 and 14 days in water, miconazole and itraconazole added into both materials resulted in significantly lower elongation percentages compared to the other antifungal agents and control (p < 0.0001), which were similar to each other (p > 0.05). CONCLUSIONS: The addition of the nystatin, chlorhexidine, and ketoconazole at MICs for C. albicans biofilm resulted in no harmful effects on the tensile strength and elongation percentage of the temporary soft denture liner materials up to 14 days.