Effect of Different Denture Base Cleansers on Surface Roughness of Heat Polymerised Acrylic Materials with Different Curing Process / Efecto de diferentes limpiadores para dentaduras en la rugosidad de la superficie de acrílicos polimerizados por calor con diferentes procesos de curado

Abstract Avoiding biofilm formation on dentures is associated with maintaining the surface properties of acrylic-based dentures. The aim of the study is to investigate the effects of two different cleaning agents (Corega and Klorhex 0.2% chlorhexidine gluconate) on surface roughness of the denture regarding efficacy of curing procedures. A total of sixty disc-shaped specimens were prepared with two different methods as long and short curing processes. The specimens were divided into subgroups according to the immersion solutions (distilled water, Corega tablet group and Klorhex 0.2% chlorhexidine gluconate group) (n=10). The samples were kept in a solution for 8 hours per day during a month. The average Ra1 (before exposure to the cleanser agent) and Ra2 (after exposure to the cleanser agent) of each sample was measured. A two- way ANOVA and post hoc Tukey test was used for statistical analysis. The solutions significantly increased the Ra values in both acrylic groups (p0.05). The long-term curing time is highly effective in decreasing the surface roughness of the acrylic base material.

Resumen Evitar la formación de biopelículas en las prótesis dentales se asocia con el mantenimiento de las propiedades de la superficie de las prótesis de base acrílica. El objetivo del estudio es investigar los efectos de dos agentes de limpieza diferentes (Corega y Klorhex 0,2% gluconato de clorhexidina) en la rugosidad de la superficie de la dentadura postiza en cuanto a la eficacia de los procedimientos de curado. Se prepararon un total de sesenta muestras en forma de disco con dos métodos diferentes como procesos de curado largos y cortos. Las muestras se dividieron en subgrupos según las soluciones de inmersión (agua destilada, grupo de pastillas Corega y grupo de gluconato de clorhexidina al 0,2%) (n=10). Las muestras se mantuvieron en una solución durante 8 horas al día durante un mes. Se midió el promedio de Ra1 (antes de la exposición al agente de limpieza) y Ra2 (después de la exposición al agente de limpieza) de cada muestra. Para el análisis estadístico se utilizó un ANOVA de dos vías y una prueba post hoc de Tukey. Las soluciones aumentaron significativamente los valores de Ra en ambos grupos acrílicos (p 0,05). El tiempo de curado a largo plazo es muy eficaz para disminuir la rugosidad de la superficie del material de base acrílica.

Effect of cleanser solutions on the retention force of oring attachment: an in vitro study

Abstract The aim of this study was to evaluate the effect of cleaning solutions on the retention force of o-ring-type overdenture attachments. The effect of four solutions on nitrile rings were evaluated: Cepacol (C), Cepacol with fluoride (CF), Listerine (L) and 0.05% sodium hypochlorite (SH); deionized water (DW) was used as a control. Matrices containing two implants and abutments and acrylic specimens with the metal capsules were obtained and divided into the groups. A simulation of 90 overnight immersions (8 h) was performed, and the tensile strength value was obtained at the beginning (T0) and in every 30 days (T1, T2 and T3) (n=6). In order to analyze o-ring surface damage after the immersions, a scanning electron microscopy (SEM) was used (n=1). For statistical analysis of the results, analysis of variance (ANOVA) and multiple comparisons with Bonferroni adjustment (test power=1.000; a=0.05) were used. There was a significant difference for the factors time (p<0.001), solution (p<0.001) and for the interaction time × solution (p<0.001). Considering the times of each solution, only for DW there was no significant loss of retention over time. Comparing the solutions in each moment, there was no difference among the solutions in T0. From T1, CF and SH provided less retention than DW (p<0.005). Through SEM it was possible to observe changes in the surface of the CF and SH nitrile o-rings. CF and SH should be avoided due to deleterious action in o-rings.

Resumo O objetivo do estudo foi avaliar o efeito de soluções higienizadoras sobre a força de retenção de encaixes do tipo o-ring. Foram avaliadas quatro soluções: Cepacol (C); Cepacol com flúor (CF), Listerine (L), hipoclorito de sódio 0,05% (HS) e água deionizada (controle/AD) em o-rings de nitrilo. Matrizes contendo dois implantes e pilares e espécimes em acrílico com as cápsulas metálicas foram obtidas e divididas entre os grupos. Foi realizada a simulação de 90 imersões noturnas (8 h), sendo obtido o valor da resistência à tração no início e a cada 30 dias (T0, T1, T2 e T3) por meio da máquina de ensaios mecânicos (n=6). Microscopia eletrônica de varredura (MEV) foi utilizada para análise de danos na superfície do o´ring após a imersão (n=1). Para análise estatística dos resultados foi utilizada análise de variância (ANOVA) e múltiplas comparações com ajuste de Bonferroni (poder do teste=1,000; a=0,05). Houve diferença significante para os fatores tempo (p<0,001), solução (p<0,001) e para interação de tempo × solução (p<0,001). Considerando-se os tempos de cada solução, apenas AD não apresentou perda significativa de retenção ao longo do tempo. Comparando as soluções em cada momento, não houve diferença entre as soluções em T0. A partir de T1, CF e HS propiciaram menor retenção quando comparados à AD (p <0,005). Através do MEV foi possível observar alterações nas superfícies dos o-rings de nitrilo imersos em CF e HS. O Cepacol com flúor e hipoclorito de sódio devem ser evitados devido à ação deletéria nos o-rings.

Effects of denture cleansers on denture material properties ­an observational case­control study / Efectos de los limpiadores de prótesis dentales sobre las propiedades del material: un estudio observacional de casos y controles

Everyday use of denture cleansers to prevent microbial colonization on dentures can affect the properties of the denture base material. Limited literature is available on the effects of denture cleanser on reinforced resins. This study aimed to evaluate and compare the effect of denture cleanser on the flexural and impact strength of conventional and reinforced heat cure acrylic resins. Materials and Methods: Rectangular shaped specimens were prepared for flexural and impact strength as per ISO 1567. The denture base resins used included conventional, high impact, nylon fiber reinforced and glass fiber reinforced heat cure acrylic resins. They were further categorized into subgroups A and B depending on immersion in distilled water or denture cleanser (3.8% sodium perborate based). The flexural strength and impact strength of specimens were measured. The study design is a observational case-control study. SPSS version 25 statistical analysis software was used, and the STROBE statement checklist was followed. Results: The mean flexural strength was highest for glass fiber reinforced heat cure resin followed by conventional heat cure resin, high impact heat cure resin and nylon reinforced heat cure resin, respectively. The mean impact strength was highest for high impact heat cure resin followed by glass fiber reinforced heat cure resin, conventional heat cure resin, and nylon fiber-reinforced resin respectively.Conclusion: All the denture base resins tested exhibited a decrease in flexural and impact strength following use of a denture cleanser.

El uso diario de limpiadores para prótesis dentales para prevenir la colonización microbiana en las prótesis puede afectar las propiedades del material base de estas. Existe literatura limitada sobre los efectos de los limpiadores de prótesis sobre resinas reforzadas. Este estudio tuvo como objetivo evaluar y comparar el efecto de un limpiador de prótesis sobre la resistencia a la flexión y al impacto de las resinas acrílicas de curado con calor convencionales y reforzadas. Material y Métodos: Muestras de forma rectangular se prepararon para testear la resistencia a la flexión y al impacto según ISO 1567. Las resinas de base de prótesis utilizadas fueron resinas acrílicas convencionales, de alto impacto, y de curado térmico reforzadas con fibra de vidrio o nylon. Posteriormente se clasificaron en los subgrupos A y B según la inmersión en agua destilada o limpiador de prótesis (3,8% de perborato de sodio). Se midieron la resistencia a la flexión y la resistencia al impacto de las muestras. El diseño del estudio fue de un estudio observacional de casos y controles. Se utilizó el software de análisis estadístico SPSS versión 25, y se siguió la guía de la declaración STROBE. Resultado: La resistencia a la flexión fue más alta para la resina de curado por calor reforzada con fibra de vidrio seguida de la resina de curado por calor convencional, la resina de curado por calor de alto impacto y la resina de curado por calor reforzada con nylon, respectivamente. La resistencia al impacto fue más alta para la resina de curado por calor de alto impacto seguida de la resina de curado por calor reforzada con fibra de vidrio, la resina de curado por calor convencional y la resina reforzada con fibra de nylon, respectivamente. Conclusión: Todas las resinas de base de prótesis probadas exhibieron una disminución en la resistencia a la flexión y al impacto después del uso de un limpiador de prótesis.

Evaluation of Interface Adhesion Between Silicone Soft Liners and Denture Base After Immersion With Denture Cleansers by Scanning Electron Microscope

@#Introduction: The compatibility of denture cleanser is crucial in the prevention of failure of adhesion between silicone soft liner and acrylic denture base, thus ensuring the durability of the prosthesis. This scanning electron microscope (SEM) study was to determine the mode of failure and measured the gap formation between silicone soft liners and Polymethylmethacrylate (PMMA) denture base after immersion in denture cleansers. Methods: A total of 135 specimens of PMMA denture base lined with three different silicone soft liners (GC Reline Soft, Mollosil and Tokuyama Sofreliner Tough) were immersed into denture cleansers (Polident® and Stearadent) daily and stored in distilled water at 37±1°C. Specimens were examined and sectioned at 2.5mm and 5.0mm from the margin after 1 day, 30 days and 90 days before analyzed. Results: No significant difference detected in the mode of failure and gap formation after one-day immersion. Adhesive failure was the commonest failure at the margin after 30 days (71.11%) and after 90 days (95.56%). However, 33.33% of specimens showed mixed failure at 5.0mm sectioned after 90 days. A significant difference of gap formation was demonstrated from Mollosil in Steradent at the margin and at 2.5 mm sectioned after 30 days and after 90 days (p<0.05). It was also observed at the margin and 5.0mm sectioned of specimens from Tokuyama in Steradent after 90 days of immersion (p<0.05). Conclusion: Specimen immersed in Steradent denture cleanser presented with wider gap formation as compared to Polident®, and adhesive failure is the commonest mode of failure.

Sodium bicarbonate: A review and its uses in dentistry

Denture stomatitis, periodontitis, and peri-implantitis are the growing problems in restorative dentistry. Chemicals play an important role as an adjuvant to mechanical cleaning of teeth, implants, surrounding tissues, and prostheses. Current mouth rinses are reported to affect the tissues and prostheses if used on a long-term basis. Sodium bicarbonate, the common baking soda, has been reported to be versatile. A search of the resources through Medline and Google Scholar was made to understand the current status of the mouth rinses and the use of sodium bicarbonate. Different MeSH and search criteria were used for the different search engines. Baking soda, being a common household item, with its ready availability, safety, minimal abrasivity, and bactericidal property makes it a patient-friendly mouthwash, component in the dentifrice, or chewing gum, which can be used on a long-term basis as an adjunct virtually free of any side effects.

Evaluation of the effect of denture cleansers on the surface roughness of hard denture base material: An In vitro study

Maintaining the oral hygiene of denture wearers is a challenge faced in modern dentistry. Biofilm formed on dentures has been associated with denture stomatitis, malodor, aspiration pneumonia, infectious endocarditis, gastrointestinal infection, and chronic obstructive pulmonary disease. Objective: The purpose of this study was to evaluate the effect of denture cleansers on the surface roughness of hard denture base material. Materials and Methods: A total of 100 heat-cure acrylic resin specimens were fabricated with dimensions 30 mm × 15 mm × 3 mm in length, width, and thickness, respectively. All specimens were distributed into four groups randomly. Three commonly prescribed denture cleansers were used for immersion in this study. Regular tap water was used for immersion in the control group. Surface roughness was determined before immersion and after immersion in denture cleansing solutions using contact profilometer. The data were subjected to statistical analysis using paired t-test, one-way analysis of variance, and Tukey's multiple post hoc test. Results: The change in surface roughness of acrylic samples immersed in Clanden group was statistically significant (P < 0.05) at individual group level. However, the change in surface roughness of acrylic samples after immersion, when compared between the groups, namely, control, Clinsodent, Clanden, and Fittydent, was not statistically significant (P > 0.05). Conclusion: Within the limitation of this study, the three denture cleansing materials, namely, Clinsodent powder, Clanden tablet, and Fittydent tablet, are safe to be prescribed as denture cleansers.

The staining effect of coffee and red tea to two kinds of denture base materials and the cleaning efficacy of four kinds of denture cleansers to the stains / 口腔疾病防治

Objective@#To compare the staining effect of coffee and red tea to the different denture base materials, and to investigate the cleaning efficacy of four denture cleansers.@*Methods @#All samples were separately soaked in 1％NaClO、 Efferdent、 Polident partial and Polident overnight for 12 times within 12 days after staining by the coffee and red tea. Then, the color values of the samples were measured by the spectrocolorimeter. @*Results @#The staining effect between coffee and red tea in the two materials was statistically significant (P < 0.05); the invisible denture materials are easily colored than heat-curing denture base resins (P < 0.05); there was also a statistical difference in the cleaning effect of the denture cleaning agents at each cycle stage (P < 0.05); the trend is different in different phases of color difference (ΔE) (P < 0.05). @*Conlusion@#Compared with the Polident partial, the cleaning efficacy of 1％NaClO、Efferdent and Polident overnight were better.

The staining effect of coffee and red tea to two kinds of denture base materials and the cleaning efficacy of four kinds of denture cleansers to the stains / 口腔疾病防治

Objective@#To compare the staining effect of coffee and red tea to the different denture base materials, and to investigate the cleaning efficacy of four denture cleansers.@*Methods@#All samples were separately soaked in 1％NaClO、 Efferdent、 Polident partial and Polident overnight for 12 times within 12 days after staining by the coffee and red tea. Then, the color values of the samples were measured by the spectrocolorimeter.@*Results @#The staining effect between coffee and red tea in the two materials was statistically significant (P < 0.05); the invisible denture materials are easily colored than heat-curing denture base resins (P < 0.05); there was also a statistical difference in the cleaning effect of the denture cleaning agents at each cycle stage (P < 0.05); the trend is different in different phases of color difference (ΔE) (P < 0.05).@*Conlusion@#Compared with the Polident partial, the cleaning efficacy of 1％NaClO、Efferdent and Polident overnight were better.

Bactericidal Effect of the Aos Denti Germ for Denture Cleansing Effervescent Tablet against Oral Microorganisms

Human mouth environment is known to include a variety bacteria, including Streptococcus spp., Staphylococcus spp., Actinomyces spp., Lactobacillus spp., Candida spp., Enterobacteriaceae, et al. Human oral microorganisms can cause dental caries, gingivitis, periodontitis, respiratory tract infection, and cardiovascular disease. Thus, right denture cleaning is essential to oral and general human health. The aim of this study was to evaluate the bactericidal effect of a sodium dichloroisocyanurate-based effervescent tablet (Aos Denti Germ, Aos Company, Chungbuk, Korea) against oral microorganisms. A total of 5 species Streptococcus spp. (Streptococcus anginosus, Streptococcus mitis, Streptococcus mutans, Streptococcus oralis, and Streptococcus sobrinus), Actinomyces oris, Candida albicans, and Escherichia coli were used in this study. All strains were exposed to the distilled water prepared with effervescent tablet. After the exposure, the mixture of strains and effervescent tablet was inoculated onto blood agar or MacConkey agar plate and cultured at 36℃. All strains were killed immediately on exposure to effervescent tablet. The results suggested that effervescent tablet could be used as an effective denture cleanser for dental hygiene.

Effect of denture cleansers on color stability and surface roughness of denture base acrylic resin.

Background: Color stability of acrylic resin is one of the most important feature for denture wearers. Many patients use detergent solutions to remove denture stains. The purpose of this study was to evaluate color stability and surface roughness of two common acrylic resins in different detergent and tea solutions. Materials and Methods: 112 acrylic resin blocks of Meliodent and Acropars (each 56 blocks) were divided into seven groups of different treatment: 1% sodium hypochlorite for 10 min a day for 1 month (H10m), 1% sodium hypochlorite for 8 hours a day for 1 week (H&h), Correga tabs solution for 8 hours a day for 1 month (C&H), tea bag for 2 hours a day for 1 month (T2 h), tea bag for 2 hours a day then 10 min in 1% sodium hypochlorite for 1 month (T-H), tea bag for 2 hours then 8 hours in the Correga tab solution a day for 1 month (T-C), and finally distilled water for 1 month as a control group (con). After specimen's treatment, color (CIE Lab) and surface roughness (Ra, μm) of samples were measured. The results were analyzed by analysis of variance (ANOVA), followed by Tukey’s HSD and Dunnett T3. Results: Group T2h exhibited a significant (P<0.05) color change and control specimens exhibited the lowest color change. Sodium hypochlorite caused a significant (P<0.05) color change in the Acropars group in comparison with the Meliodent group. In the Correga tab solution the difference was not significant (P=0.155). There was a significant (P<0.05) color change in the T-H treatment. The Acropars and Meliodent acrylic resin did not a show significant difference in surface roughness after different treatments. Conclusion: Sodium hypochlorite 1% for 10 minutes a day in a month is the recommended hygiene protocol. The color stability of acryl is brand-type dependent but surface roughness is not.

Anticandidal efficacy of denture cleansing tablet, Triphala, Aloe vera, and Cashew leaf on complete dentures of institutionalized elderly.

With an increase in the number of dependent elderly, there is a need to introduce few natural products for denture cleansing, which are easily and economically available. Hence the aim of this study was to compare the anticandidal efficacy of denture cleansing tablet (sodium bicarbonate and sodium perborate monohydrate), Triphala (Phyllanthus emblica, Terminalia chebula and Terminalia belerica fruits powders in equal proportion), cashew leaf, Aloe vera and water (control) on complete dentures of institutionalized elderly. Study population consisted of 50 institutionalized elderly of Mangalore, Karnataka, with 10 in each group. Swabs were collected from the dentures before and after the use of denture cleansing tablet, Triphala, cashew leaf, Aloe vera, and water (control). Thereafter, the swabs were cultured on Sabouraud dextrose agar and the total candida counts were determined. Denture cleansing tablet and Triphala Churna showed a statistically significant reduction in Candida counts (P < 0.05). Denture cleansing tablet and Triphala Churna were found to be more effective.

Effect of denture cleansers on Candida albicans biofilm formation over resilient liners

PURPOSE: The purpose of this study was to analyze the effect of denture cleansers on Candida albicans biofilm formation over resilient liners and to evaluate compatibility between resilient liners and denture cleansers. MATERIALS AND METHODS: Acrylic resin (Lucitone 199(R)) and 3 resilient liners (COE-SOFT(TM), GC RELINE(TM) and SOFRELINER TOUGH TOUGH(R)) were incubated in denture cleansers (Polident(R) and Cleadent(R)) for 8 hours a day and in unstimulated saliva for 16 hours a day (n=25/gp) for 60 days. Two-way and three-way repeated measures ANOVA were performed to compare the surface roughness (Ra), pH and C. albicans binding level by radioisotope (alpha=0.05). The statistical significance of the relation between Ra and adhesion was evaluated by correlation analysis. RESULTS: The degree of Ra was significantly decreased in the following order: COE-SOFT(TM), acrylic resin, GC RELINE(TM) and SOFRELINER TOUGH(R). The immersion in denture cleansers significantly increased Ra of resilient liners, except for SOFRELINER TOUGH(R) in Cleadent(R). No significant differences in pH curves were observed among groups immersed in distilled water and denture cleansers. The binding levels of C. albicans were significantly decreased in the following order: COE-SOFT(TM), GC RELINE(TM), SOFRELINER TOUGH(R), and acrylic resin. The immersion in Cleadent(R) seemed to decrease C. albicans binding level on GC RELINE(TM) and SOFRELINER TOUGH(R). CONCLUSION: Based on the C. albicans binding levels results, it is not recommended to immerse COE-SOFT(TM) in denture cleansers, and GC RELINE(TM) and SOFRELINER TOUGH(R) should be immersed in Cleadent(R).

Effectiveness of Denture Cleanser Associated With Microwave Disinfection and Brushing of Complete Dentures: In Vivo Study

Complete dentures acts as a reservoir for microbial colonization, which may lead to systemic infections. Microwave irradiation has been used as an efficient method of denture disinfection. Even though current methods eliminate denture-base microorganisms, a recurrence rate of denture stomatitis (DS) is still observed among denture-wearing patients. It was hypothesized that microwave disinfection kills microorganisms but do not remove dead bacteria from the denture surface. To test this hypothesis, the biofilm found in the dentures of 10 patients with DS was evaluated. In addition, the effects of microwave irradiation plus brushing (MW+B) on the denture biofilm and the combination of denture cleanser with microwave irradiation and brushing (MW+DC+B) for the removal of denture-accumulating microorganisms were investigated. Microbiological data were analyzed statistically by nonparametric analysis (Friedman/Wilcoxon, α=0.05). MW+B and MW+DC+B were effective in reducing the rate of microorganisms (99.2% and 99.5% respectively), but without significant difference between them (p=0.553). However, it was observed that the complete removal of microorganisms from denture surface was only possible when all regimens were combined (MW+DC+B). Microwave irradiation in combination with soaking in denture cleanser and brushing effectively disinfected the dentures and removed denture biofilm.

Próteses totais agem como um reservatório para a colonização microbiana, que pode levar a infecções sistêmicas. Irradiação com microondas tem sido usada como um método eficiente de desinfecção das próteses. Apesar dos métodos atuais eliminarem os microorganismos da base protética, uma taxa de recidiva ainda é observada entre pacientes que usam próteses dentárias. Hipotetizamos que a desinfecção com microondas consegue matar os microorganismos, mas não remove as bactérias mortas da superfície da prótese. Para testar essa hipótese, o biofilme encontrado nas próteses de 10 pacientes com estomatite protética foi analisado. Além disso, os efeitos da irradiação por microondas + escovação (MW+B) no biofilme da prótese e a associação de um higienizador de prótese com a irradiação por microondas e escovação (MW+DC+B) para a remoção dos microorganismos da prótese foram investigados. Dados microbiológicos foram avaliados por análise não paramétrica (Friedman/Wilcoxon, α=0,05). MW+B e MW+DC+B foram efetivos em reduzir a taxa de microorganismos (99,2% e 99,5%, respectivamente), mas não houve diferença significativa entre eles (p=0,553). Entretanto, observamos que a completa remoção dos microorganismos só foi possível quando todos os métodos foram associados (MW+DC+B). Irradiação por microondas associada à imersão em higienizador de prótese e escovação efetivamente desinfetou a prótese e removeu o biofilme da prótese.

Effect of experimental Ricinus communis solution for denture cleaning on the properties of acrylic resin teeth

This study evaluated Knoop hardness, surface roughness and color alteration of artificial teeth for dentures after immersion in water, 1 percent sodium hypochlorite and an experimental solution of 2 percent Ricinus communis (RC). Thirty specimens of Vipi, Biolux and Trilux were analyzed. Tests of Knoop hardness, surface roughness and color alteration were conducted immediately after specimen preparation (T0) and after two immersion protocols for 15 days (ΔT15) and 183 days (ΔT183). Data variation (ΔT) were subjected to ANOVA and Tukey's test (p<0.05). At ΔT15, Vipi presented hardness increase and Biolux presented the highest variation (p=0.01). RC caused the highest increase in hardness (p=0) and the lowest increase (p=0.005) in roughness. Biolux presented the lowest color alteration (p =0). At ΔT183, Trilux underwent the highest hardness variation (p=0). Biolux presented an increase in roughness (p=0). There was no significant differences in color alteration among the artificial teeth (p=0.06) and among solutions (p=0.08) after 183 days of immersion. All solutions (distilled water, 1 percent sodium hypochlorite and 2 percent RC) caused alterations on the analyzed properties. Both immersion protocols caused alterations on the analyzed properties.

Este estudo avaliou a dureza Knoop, rugosidade e alteração de cor de dentes artificiais após imersão em água, hipoclorito de sódio 1 por cento e solução de Ricinus communis 2 por cento (RC). Trinta espécimes de dentes das marcas Vipi, Biolux e Trilux foram analisados. Os testes de dureza, rugosidade e alteração de cor foram realizados após a obtenção dos espécimes (T0) e após dois protocolos de imersão nas soluções por 15 dias (Δ15) e 183 dias (Δ183). A variação dos dados (ΔT) foi submetida à ANOVA e teste de Tukey (p<0,05). Em ΔT15, Vipi apresentou aumento da dureza e Biolux, a maior variação (p =0,01). RC causou o maior aumento na dureza (p=0). RC causou o menor aumento na rugosidade (p=0,005). Biolux apresentou a menor alteração de cor (p=0). Em ΔT183, Trilux apresentou a maior variação na dureza. (p=0). Biolux apresentou aumento na rugosidade (p=0). Não houve diferença significante na alteração de cor entre dentes (p=0,06) e entre soluções (p=0,08) após 183 dias de imersão. Todas as soluções (água destilada, hipoclorito de sódio 1 por cento e RC) causaram alterações nas propriedades analisadas. Ambos os protocolos de imersão causaram alterações nas propriedades analisadas.

Influence of peracetic acid at acrylic resin properties / Influência do ácido peracético nas propriedades de uma resina acrílica

PURPOSE: To evaluate the influence of peracetic acid immersion on water sorption, solubility and microhardness of heat and self-cured acrylic resins. METHODS: Thirty specimens of each type of acrylic resin were produced for sorption, solubility and microhardness evaluation. Sorption and solubility were evaluated based on ISO1567. For the microhardness test, specimens (20.0×5.0×10.0 mm) were made and evaluated under a 100 g load for 15 s. The test groups were submitted to a peracetic acid 0.2% immersion for 10 minutes. Data of sorption and solubility were analyzed by two way ANOVA and, hardness values, by paired t-test. RESULTS: Values of sorption and solubility were in agreement with ISO1567 requirements to both groups and ranged, in µg/mm³, for sorption from 22.28 (±4.40) to 24.25 (±3.27), and from 1.09 (±0.16) to 1.29 (±0.10) for solubility. Solubility showed a statistically significant difference between the two types of resin at test group. There was no statistical significant difference at the microhardness values. CONCLUSION: In this study, immersion in peracetic acid solution 0.2% showed no alterations at acrylic resin properties tested.Peracetic acid could be recommended to replace the conventional agents for the disinfection of acrylic resin devices.

OBJETIVO: Avaliar a influência da imersão em ácido peracético sobre a sorção, solubilidade e microdureza de resinas acrílicas termo e autopolimerizada. METODOLOGIA: Trinta corpos de prova de cada resina acrílica foram confeccionados para avaliação da sorção, solubilidade e microdureza. A sorção e a solubilidade foram avaliadas de acordo com a ISO 1567. Para a determinação da microdureza, os corpos de prova (20×5×10 mm) foram confeccionados e avaliados com uma carga de 100 g por 15 s. Os grupos teste foram imersos em ácido peracético 0,2% por 10 minutos. Os dados de sorção e solubilidade foram analisados com ANOVA de duas vias e de dureza por teste t pareado. RESULTADOS: Os valores de sorção e solubilidade ficaram de acordo com as especificações da ISO 1567 para ambos os grupos e no ensaio de sorção variaram entre 22,28 (±4,40) até 24,25 (±3,27), e de 1,09 (±0,16) até 1,29 (±0,10) para solubilidade, em µg/mm³. A solubilidade apresentou diferença estatisticamente significativa entre os dois tipos de resina após imersão em ácido peracético. Os valores de microdureza não apresentaram diferença estatisticamente significativa entre os grupos. CONCLUSÃO: A imersão em ácido peracético 0,2% não alterou as propriedades avaliadas das resinas acrílicas.

Cleansing effect of the alkaline ionized water on microorganisms of the denture surface / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the cleansing effect of recently developed alkaline ionized water, e-WASH, on microorganisms of the denture surface. MATERIALS AND METHODS: Removable partial and complete dentures were randomly assigned to the experimental group of 41 dentures, and the control group of 26. The denture was immersed in the e-WASH solution (experimental group), or tap water (control group) for 5 minutes. The plaque was collected from the denture surface before and after immersion, and smeared on the slide glass. Amount and motility of microorganisms were compared according to the morphology and strain of microorganisms, using the phase contrast microscope. Statistical analysis was accomplished with paired t-test and independent t-test at 95% confidence level (P<.05). RESULTS: 1. The amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were decreased after denture cleansing with the alkaline ionized water, e-WASH (P<.05). But in the control group, only the amount of cocci showed a significant difference (P<.05), but no difference from the others. There were no differences in other analysis. 2. In the experimental group, the amount of cocci, bacilli, filamentous, spiral/comma, and the motility of bacilli, filamentous, and spiral/comma were smaller and more inactive compared to the control group (P<.05). CONCLUSION: These results indicated that the alkaline ionized water, e-WASH could effectively reduce the amount and motility of the experimented microorganisms on the denture surface, and that e-WASH could be recommended as an effective denture cleanser.

Effect of a denture cleanser on hardness, roughness and tensile bond strength of denture liners

Aim: This study aim to investigate the effect of a denture cleanser on hardness, roughness and tensile bond strength of a rigid (Kooliner) and a soft denture liner (Elite Soft) after 7, 60 and 120 days of immersion. Methods: Thirty circular and twenty rectangular specimens of each material were randomly distributed in two groups: control - immersion in artificial saliva at 37°C; and experimental - immersion in artificial saliva at 37ºC combined with immersion in the cleanser for 5 min. Hardness was measured using either a Vickers or Shore A hardness tester, and a surface roughness tester was used to measure the surface roughness. Tensile bond strength was carried out on a universal testing machine. Data were analyzed statistically by ANOVA or Kruskal-Wallis test (alpha=0.05). Results: No significant difference was found between the groups for the tested properties (p>0.05). There was an increase in the hardness of both materials after 60 days (p>0.05). No difference between the immersion periods was found for the roughness of Kooliner (p>0.05), although the roughness of Elite Soft decreased after 120 days in both groups (p>0.05). Kooliner presented higher tensile bond strength than Elite Soft (p>0.05). Conclusions: Both materials showed alterations on the tested properties during the experimental period, but these changes were not promoted by the denture cleanser.