This study aims to compare the physical properties of denture base resin after staining by beverages, treatment by four cleaning methods, and selecting the optimal cleaning method. Two hundred and ninety square Lucitone dental acrylic specimens were fabricated. Three relevant experiences are performed. Part I will compare cleaning methods effects on physical properties of denture resin. The purpose of this part is to test the effects of different cleaning methods on the physical properties of the denture resin on ideal condition (without stain). Part II will compare the staining effects on denture resin. The purpose of this part is to find the impact of different dyes on the physical properties of the denture resin without cleaning. Part III will compare staining and cleaning effects on denture resin. The purpose of this part is to select the best cleaning methods with less defect and more efficient for denture cleaning. Significance differences are found between different cleaning methods and stains. For all stain, denture cleanser combined brushing is more efficient to remove the stain than other cleaning methods. However, this method causes significate damage to denture base resin. Meanwhile, ultrasonic combine denture cleanser showed lower changes in surface roughness, weight and thickness, and higher surface hardness. In red wine staining, cleaning denture with ultrasound only showed lower differences and higher surface hardness. Within the scope of this study, the optimal selections of denture base cleaning methods for different stains are suggested. For coffee and tea stains, ultrasonication after cleanser application causes fewer effects on physical properties and better efficiency for stain removal than other cleaning methods. For red wine stains, cleaning dentures with ultrasound only cause a fewer impact on material properties and more efficient stain removal. In the clinic, home-care and cleaning protocol should explain to denture patient at the delivery appointment. Instead of giving the universal instruction, customization cleaning protocols are preferred to individual patients. Social hobbies especially the diet of the patient should be analyzed individually. According to the present study, a customized combined cleaning protocol can recommend to the individual patient and the improvement of denture longevity can be predicted. / 2020-08-06T00:00:00Z

OBJECTIVE: To assess the effect of denture cleansers on the mechanical and optical properties such as color stability, surface hardness, surface roughness, and flexural strength of the 3D printed denture acrylics in comparison to heat polymerized denture acrylics. MATERIALS AND METHODS: A total of 216 disc specimens (12 mm × 2mm) were made from Lucitone Digital Print, DENTCA Denture Base II, Formlabs denture resin, and Lucitone 199. Each type of acrylic was divided into four sub-groups, Efferdent, Polident, dish soap and control group in water. Specimens of each material were exposed to a total of 28 cycles of immersion in denture cleanser, while being stored in water in an incubator at 37°C in between cycles to test for color stability, surface roughness, microhardness and biaxial flexural strength. Baseline values were obtained for color, hardness, surface roughness, and biaxial flexural strength using a CIE L*a*b* color space by spectrophotometer, Vickers microhardness in hardness tester, line Ra by profilometer, and ball-on-three-ball fixture with universal testing machine respectively. Color, surface roughness, and surface hardness values were obtained at the 8th, 16th, and 28th cycles in order to compare color stability along with changes in surface roughness and surface hardness. Biaxial flexural strength values were performed for specimens at the 28th cycle as a destructive test to compare values of treated and untreated specimens. SEM analysis was performed to assess fracture behavior and microstructural changes. The differences between the tested materials and the treatment effects were statistically analyzed using the Tukey HSD test (a=0.05) and MANOVA test (a=0.05) RESULTS: The greatest significant change in color was seen in Lucitone 199 specimens (P value <0.0001) when exposed to dish soap. Lucitone 199 and Lucitone Digital Print had the significantly lowest microhardness values (P value< 0.0001) after exposure to treatments, especially dish soap. Surface roughness was significantly higher for all 3D specimens initially (P value <0.001), however with exposure to Efferdent and Polident, Lucitone 199 specimens had the greatest significant increase in surface roughness. The surface roughness of 3D printed specimens did not significantly increase with exposure to treatments. The biaxial flexural strength of all materials decreased significantly with the exposure to all treatments (P value< 0.0001). Overall, Lucitone 199 had the lowest flexural strength in both treatment and control groups compared to all the 3D printed materials. Formlabs was significantly affected by exposure to treatments,and had the greatest decrease in biaxial flexural strength (P value <0.0001). CONCLUSION: Within the limitations of this study, we can conclude that 3D printed materials in this study are more color stable that the heat-polymerized Lucitone 199. In regards to microhardness, 3D printed materials except for Lucitone Digital Print have higher microhardness values than heat-polymerized materials. Although Lucitone 199 had a smoother surface as prepared, the 3D printed materials in this study maintained their roughness values throughout the study, whereas Lucitone 199 showed a significant increase in roughness. The properties of 3D printed materials show a promising future for their use in treating edentulous patients. Although there are limitations to this study, it is safe to say that denture cleansers are safe to use with 3D printed dentures as long as the manufacturer’s instructions are correctly followed.

A higienização das próteses removíveis é fundamental para a longevidade do tratamento e prevenção de patologias orais. O objetivo deste estudo foi avaliar o efeito de higienizadores de imersão nas superfícies da liga metálica e resina acrílica termopolimerizável de Prótese Parcial Removível (PPR), simulando 180 dias. Discos (12 mm x 3 mm) foram confeccionados com ligas metálicas de cobalto-cromo para PPR: Vera PDI® (VP) e DeguDent® (DD). Cada disco metálico foi incluído em mufla previamente preparada por matrizes de teflon (38 mm x 18 mm x 4 mm), incorporando-se o disco metálico à resina acrílica termopolimerizável. Os espécimes (n= 5) foram imersos nas seguintes soluções: água destilada (grupo controle - AD), hipoclorito de sódio 0,05% (HS), Cepacol® (cloreto de cetilpiridínio 0,005% - CE), Periogard® (digluconato de clorexidina 0,12% - PE), Corega Tabs® (peróxido alcalino e enzima - CT), Polident® (peróxido alcalino e enzima - PO) e Medical Interporous Dentures® (ácido cítrico - MI). Foram realizadas análise da estabilidade de cor por meio de espectrocolorímetro, análise visual da presença de manchas no metal, análise da perda de massa em balança de alta precisão e análise da rugosidade por meio de rugosímetro. Como estudo complementar, foram realizadas análises quantitativas da liberação de íons (cobalto e cromo) em cada solução com espectrômetro de massas e análises ópticas e qualitativas com microscópio eletrônico de varredura (MEV) e espectrometria de energia dispersiva de Raios-X (EDS). Os resultados de rugosidade, alteração de cor e massa apresentaram distribuição normal e homogênea, tendo sido submetidos à ANOVA e teste de Tukey (p< 0,05). Quanto à rugosidade (Ra&micro;m), não houve diferença estatisticamente significante entre as soluções e ligas tanto para o metal quanto para a resina. Com relação à alteração de cor da resina acrílica termopolimerizável (&Delta;E), houve diferença estatisticamente significante entre as ligas, soluções e na interação liga x solução. As soluções AD, CE e PE propiciaram menores valores que as demais. A resina associada à DD apresentou maior alteração de cor do que quando associada à VP (1,06 ± 0,51 e 0,51 ± 0,28, respectivamente). Com relação à presença de manchas no metal, o HS propiciou manchamento em 100% dos espécimes. O grupo MI/DD propiciou em 60% e o MI/VP em 40% dos espécimes. Quando avaliada a alteração de massa (g), as soluções CT e MI propiciaram maiores valores. Entre as ligas, a VP apresentou maior perda de massa. Com relação à liberação de íons cobalto e cromo, a solução de HS e a MI propiciaram maior liberação e quando comparadas as ligas, VP apresentou maior liberação de íons. Com o MEV pôde-se verificar que houve corrosão generalizada com o HS e por pites com a MI. Concluiu-se que as soluções CE, PE e PO não apresentaram efeitos deletérios podendo ser auxiliares à escovação para higienização de PPR. / The hygiene care of the removable dentures is required for the longevity of the treatment and prevention of oral diseases. The aim of this study was to evaluate the effect of denture cleansers on the surfaces of the alloys and heat-polymerized acrylic resin for removable partial denture (RPD), simulating a period of 180 days. Circular specimens (12 mm x 3 mm) had been fabricated with cobalt-chromium alloys: Vera PDI&trade; (VP) and DeguDent&trade; (DD). The cast specimens were centered in the moulds previously prepared by matrices of teflon (38 mm x 18 mm x 4 mm) and the acrylic resin was inserted. The specimens (n= 5) had been immersed in the following solutions: distilled water (control - DW), sodium hypochlorite 0.05% (SH), Cepacol&trade; (cetilpiridinium chloride 0.005% - CE), Periogard&trade; (chlorexidine gluconate 0.12% - PE), Corega Tabs&trade; (alkaline peroxide and enzyme - CT), Polident&trade; (alkaline peroxide and enzyme - PO) and Medical Interporous Dentures&trade; (citric acid - MI). The color stability was analyzed using a colorimeter, and the presence of tarnishes on the metal was performed by a visual analysis. The weight loss was measured with a precision balance and the surface roughness was analyzed with a surf-test analyzer. As complementary analyzes a quantitative study of ions release (cobalt and chromium) using inductively mass spectrometry and optical and qualitative analyses with scanning electron microscopy (SEM) associated to dispersive energy spectrometry were performed. The results of roughness, color stability and weight loss presented normal and homogeneous distribution and were submitted to ANOVA (p &le; 0.05) and Tukey test. There was no significant difference among the solutions and between the alloys for both metal and resin roughness (Ra &micro;m). The acrylic resin color stability (&Delta;E) was analyzed and showed significant difference among the solutions, alloys and interaction. AD, CE and PE solutions presented the lowest values of color changes. The resin associated to DD presented higher color change than when associated with the VP (1.06 ± 0.51 and 0.51 ± 0.28, respectively). The HS caused tarnishes on 100% of specimens. The MI/DD group provided 60% and the MI/VP in 40% of specimens. When was analyzed the mass loss (g), the solutions CT and MI had the higher values. Between the alloys VP presented higher weight loss. HS and MI presented greater ionic release and between the alloys, VP presented greater release. With the SEM it was possible observe the presence of widespread corrosion in the HS group and pites corrosion in the MI group. It was concluded that CE, PE, CT and PO solutions had no deleterious effects on the compounds of RPD and may be indicate as auxiliaries to brushing in the RPD hygiene care.

A higienização das próteses removíveis é fundamental para a longevidade do tratamento e prevenção de patologias orais. O objetivo deste estudo foi avaliar o efeito de higienizadores de imersão nas superfícies da liga metálica e resina acrílica termopolimerizável de Prótese Parcial Removível (PPR), simulando 180 dias. Discos (12 mm x 3 mm) foram confeccionados com ligas metálicas de cobalto-cromo para PPR: Vera PDI® (VP) e DeguDent® (DD). Cada disco metálico foi incluído em mufla previamente preparada por matrizes de teflon (38 mm x 18 mm x 4 mm), incorporando-se o disco metálico à resina acrílica termopolimerizável. Os espécimes (n= 5) foram imersos nas seguintes soluções: água destilada (grupo controle - AD), hipoclorito de sódio 0,05% (HS), Cepacol® (cloreto de cetilpiridínio 0,005% - CE), Periogard® (digluconato de clorexidina 0,12% - PE), Corega Tabs® (peróxido alcalino e enzima - CT), Polident® (peróxido alcalino e enzima - PO) e Medical Interporous Dentures® (ácido cítrico - MI). Foram realizadas análise da estabilidade de cor por meio de espectrocolorímetro, análise visual da presença de manchas no metal, análise da perda de massa em balança de alta precisão e análise da rugosidade por meio de rugosímetro. Como estudo complementar, foram realizadas análises quantitativas da liberação de íons (cobalto e cromo) em cada solução com espectrômetro de massas e análises ópticas e qualitativas com microscópio eletrônico de varredura (MEV) e espectrometria de energia dispersiva de Raios-X (EDS). Os resultados de rugosidade, alteração de cor e massa apresentaram distribuição normal e homogênea, tendo sido submetidos à ANOVA e teste de Tukey (p< 0,05). Quanto à rugosidade (Ra&micro;m), não houve diferença estatisticamente significante entre as soluções e ligas tanto para o metal quanto para a resina. Com relação à alteração de cor da resina acrílica termopolimerizável (&Delta;E), houve diferença estatisticamente significante entre as ligas, soluções e na interação liga x solução. As soluções AD, CE e PE propiciaram menores valores que as demais. A resina associada à DD apresentou maior alteração de cor do que quando associada à VP (1,06 ± 0,51 e 0,51 ± 0,28, respectivamente). Com relação à presença de manchas no metal, o HS propiciou manchamento em 100% dos espécimes. O grupo MI/DD propiciou em 60% e o MI/VP em 40% dos espécimes. Quando avaliada a alteração de massa (g), as soluções CT e MI propiciaram maiores valores. Entre as ligas, a VP apresentou maior perda de massa. Com relação à liberação de íons cobalto e cromo, a solução de HS e a MI propiciaram maior liberação e quando comparadas as ligas, VP apresentou maior liberação de íons. Com o MEV pôde-se verificar que houve corrosão generalizada com o HS e por pites com a MI. Concluiu-se que as soluções CE, PE e PO não apresentaram efeitos deletérios podendo ser auxiliares à escovação para higienização de PPR. / The hygiene care of the removable dentures is required for the longevity of the treatment and prevention of oral diseases. The aim of this study was to evaluate the effect of denture cleansers on the surfaces of the alloys and heat-polymerized acrylic resin for removable partial denture (RPD), simulating a period of 180 days. Circular specimens (12 mm x 3 mm) had been fabricated with cobalt-chromium alloys: Vera PDI&trade; (VP) and DeguDent&trade; (DD). The cast specimens were centered in the moulds previously prepared by matrices of teflon (38 mm x 18 mm x 4 mm) and the acrylic resin was inserted. The specimens (n= 5) had been immersed in the following solutions: distilled water (control - DW), sodium hypochlorite 0.05% (SH), Cepacol&trade; (cetilpiridinium chloride 0.005% - CE), Periogard&trade; (chlorexidine gluconate 0.12% - PE), Corega Tabs&trade; (alkaline peroxide and enzyme - CT), Polident&trade; (alkaline peroxide and enzyme - PO) and Medical Interporous Dentures&trade; (citric acid - MI). The color stability was analyzed using a colorimeter, and the presence of tarnishes on the metal was performed by a visual analysis. The weight loss was measured with a precision balance and the surface roughness was analyzed with a surf-test analyzer. As complementary analyzes a quantitative study of ions release (cobalt and chromium) using inductively mass spectrometry and optical and qualitative analyses with scanning electron microscopy (SEM) associated to dispersive energy spectrometry were performed. The results of roughness, color stability and weight loss presented normal and homogeneous distribution and were submitted to ANOVA (p &le; 0.05) and Tukey test. There was no significant difference among the solutions and between the alloys for both metal and resin roughness (Ra &micro;m). The acrylic resin color stability (&Delta;E) was analyzed and showed significant difference among the solutions, alloys and interaction. AD, CE and PE solutions presented the lowest values of color changes. The resin associated to DD presented higher color change than when associated with the VP (1.06 ± 0.51 and 0.51 ± 0.28, respectively). The HS caused tarnishes on 100% of specimens. The MI/DD group provided 60% and the MI/VP in 40% of specimens. When was analyzed the mass loss (g), the solutions CT and MI had the higher values. Between the alloys VP presented higher weight loss. HS and MI presented greater ionic release and between the alloys, VP presented greater release. With the SEM it was possible observe the presence of widespread corrosion in the HS group and pites corrosion in the MI group. It was concluded that CE, PE, CT and PO solutions had no deleterious effects on the compounds of RPD and may be indicate as auxiliaries to brushing in the RPD hygiene care.

A higienização das próteses é de fundamental importância para a longevidade do tratamento reabilitador. Entretanto, é necessário analisar os efeitos que os higienizadores podem causar nas superfícies que compõem uma prótese. Deste modo, o objetivo deste estudo foi avaliar os efeitos de pastilhas efervescentes à base de peróxido alcalino em liga de cobalto cromo (Co-Cr), utilizada em Prótese Parcial Removível (PPR). A partir de uma matriz metálica, padrões de cera em forma de disco (12 mm x 3 mm) foram confeccionados para posterior fundição. Os espécimes metálicos (n=16) foram imersos nas soluções: água deionizada (controle), Polident 3 minutes®, Steradent®, Efferdent®, Polident for Partials® e Corega Tabs®. Foi realizada a análise da rugosidade (n=10) por meio de rugosímetro, antes (t0) e após 5 períodos de simulação de ½, 1, 2, 3, 4 e 5 anos de imersão nos higienizadores. Foram realizadas análises complementares quantitativas da liberação de íons (n=5) de cobalto (Co), cromo (Cr) e molibdênio (Mo) em cada solução e análises qualitativas em um espécime de cada grupo, por meio de Microscopia Eletrônica de Varredura (MEV) e Espectrometria de Energia Dispersiva de Raios X (EDS). A distribuição dos dados de rugosidade (&mu;m) apresentou-se não normal. Foi utilizada estatística não-paramétrica (&alpha;=0,05). Tanto para o fator solução (Kruskall Wallis, ½ ano (p=0,900), 1 ano (p=0,277), 2 anos (p=0,227), 3 anos (p=0,086), 4 anos (p=0,657) e 5 anos (p=0,856), como para o fator tempo (Friedman, p=0,137) não houve diferença significante. Com relação à liberação de íons (&mu;g/L), a distribuição dos dados apresentou-se normal. De acordo com a estatística (&alpha;=0,05, ANOVA e teste de Tukey), Corega Tabs®, Efferdent® e água deionizada promoveram maior liberação de íons Co do que o Steradent® (p=0,003). Quanto aos íons Cr (p=0,000), Corega Tabs® propiciou maior liberação quando comparado a água deionizada, Steradent® e Polident 3 minutes®. Em relação aos íons Mo (p=0,001), o Efferdent® promoveu maior liberação. No MEV pode-se verificar que as soluções não apresentaram efeitos deletérios sobre as superfícies. Conclui-se que todas as pastilhas avaliadas não ocasionaram danos, entretanto, Steradent® foi a que propiciou menor liberação de íons, sendo indicada com maior segurança para higienização de superfícies metálicas de PPR. / The hygiene care of the removable dentures is of most importance for the longevity of the rehabilitation treatment. However, it is necessary to analyze the effects that denture cleansers can cause on the surfaces of prosthesis. Thus, the aim of this study was to evaluate the effect of alkaline peroxide-effervescent tablets on the surfaces of the cobalt-chromium alloys (Co-Cr), used in removable partial dentures (RPD). Circular specimens (12 mm x 3 mm) were fabricated with cobalt-chromium alloys. The specimens (n= 16) were immersed in the following solutions: deionized water (control), Polident 3 minutes&trade;, Steradent&trade;, Efferdent&trade;, Polident for Partials&trade; and Corega Tabs&trade;. The surface roughness (n=10) was analyzed with a surf-test analyzer, before and after 5 periods that corresponds to the simulation of ½, 1, 2, 3, 4 and 5 years of immersion in the cleansers. As complementary analysis, it was performed a quantitative study of ions release (n=5) for cobalt (Co), chromium (Cr) and molybdenum (Mo) in each solution and qualitative analysis with scanning electron microscopy (SEM) associated to Energy-dispersive X-ray spectroscopy (EDS). The results of surface roughness had presented no normal. In nonparametric statistics (&alpha; = 0.05), both of the solution factor Kruskall Wallis, ½ year (p=0.900), 1 year (p=0.277), 2 years (p=0.227), 3 years (p=0.086), 4 years (p=0.657) and 5 years (p=0.856), such as time factor (Friedman, p = 0.137), there was no significant difference. The results of ionic release presented a normal distribution and they were submitted to ANOVA (p=0.05) and Tukey test. The solutions Corega Tabs®, Efferdent® and deionized water presented greater Co ionic release than Steradent® (p=0.003). For Cr ions (p=0.000), Corega Tabs® had greater ionic release than deionized water, Steradent® and Polident 3 minutes®. Regarding Mo ions (p=0.001), Efferdent® showed greater release. With SEM, it was possible to verify that the solutions showed no deleterious effects on the specimen surfaces. It was concluded that no deleterious effects on metal surface was caused, however, Steradent® presented the smallest ionic release, and can be indicated more safely for cleaning metal surfaces of RPD.

A higienização das próteses é de fundamental importância para a longevidade do tratamento reabilitador. Entretanto, é necessário analisar os efeitos que os higienizadores podem causar nas superfícies que compõem uma prótese. Deste modo, o objetivo deste estudo foi avaliar os efeitos de pastilhas efervescentes à base de peróxido alcalino em liga de cobalto cromo (Co-Cr), utilizada em Prótese Parcial Removível (PPR). A partir de uma matriz metálica, padrões de cera em forma de disco (12 mm x 3 mm) foram confeccionados para posterior fundição. Os espécimes metálicos (n=16) foram imersos nas soluções: água deionizada (controle), Polident 3 minutes®, Steradent®, Efferdent®, Polident for Partials® e Corega Tabs®. Foi realizada a análise da rugosidade (n=10) por meio de rugosímetro, antes (t0) e após 5 períodos de simulação de ½, 1, 2, 3, 4 e 5 anos de imersão nos higienizadores. Foram realizadas análises complementares quantitativas da liberação de íons (n=5) de cobalto (Co), cromo (Cr) e molibdênio (Mo) em cada solução e análises qualitativas em um espécime de cada grupo, por meio de Microscopia Eletrônica de Varredura (MEV) e Espectrometria de Energia Dispersiva de Raios X (EDS). A distribuição dos dados de rugosidade (&mu;m) apresentou-se não normal. Foi utilizada estatística não-paramétrica (&alpha;=0,05). Tanto para o fator solução (Kruskall Wallis, ½ ano (p=0,900), 1 ano (p=0,277), 2 anos (p=0,227), 3 anos (p=0,086), 4 anos (p=0,657) e 5 anos (p=0,856), como para o fator tempo (Friedman, p=0,137) não houve diferença significante. Com relação à liberação de íons (&mu;g/L), a distribuição dos dados apresentou-se normal. De acordo com a estatística (&alpha;=0,05, ANOVA e teste de Tukey), Corega Tabs®, Efferdent® e água deionizada promoveram maior liberação de íons Co do que o Steradent® (p=0,003). Quanto aos íons Cr (p=0,000), Corega Tabs® propiciou maior liberação quando comparado a água deionizada, Steradent® e Polident 3 minutes®. Em relação aos íons Mo (p=0,001), o Efferdent® promoveu maior liberação. No MEV pode-se verificar que as soluções não apresentaram efeitos deletérios sobre as superfícies. Conclui-se que todas as pastilhas avaliadas não ocasionaram danos, entretanto, Steradent® foi a que propiciou menor liberação de íons, sendo indicada com maior segurança para higienização de superfícies metálicas de PPR. / The hygiene care of the removable dentures is of most importance for the longevity of the rehabilitation treatment. However, it is necessary to analyze the effects that denture cleansers can cause on the surfaces of prosthesis. Thus, the aim of this study was to evaluate the effect of alkaline peroxide-effervescent tablets on the surfaces of the cobalt-chromium alloys (Co-Cr), used in removable partial dentures (RPD). Circular specimens (12 mm x 3 mm) were fabricated with cobalt-chromium alloys. The specimens (n= 16) were immersed in the following solutions: deionized water (control), Polident 3 minutes&trade;, Steradent&trade;, Efferdent&trade;, Polident for Partials&trade; and Corega Tabs&trade;. The surface roughness (n=10) was analyzed with a surf-test analyzer, before and after 5 periods that corresponds to the simulation of ½, 1, 2, 3, 4 and 5 years of immersion in the cleansers. As complementary analysis, it was performed a quantitative study of ions release (n=5) for cobalt (Co), chromium (Cr) and molybdenum (Mo) in each solution and qualitative analysis with scanning electron microscopy (SEM) associated to Energy-dispersive X-ray spectroscopy (EDS). The results of surface roughness had presented no normal. In nonparametric statistics (&alpha; = 0.05), both of the solution factor Kruskall Wallis, ½ year (p=0.900), 1 year (p=0.277), 2 years (p=0.227), 3 years (p=0.086), 4 years (p=0.657) and 5 years (p=0.856), such as time factor (Friedman, p = 0.137), there was no significant difference. The results of ionic release presented a normal distribution and they were submitted to ANOVA (p=0.05) and Tukey test. The solutions Corega Tabs®, Efferdent® and deionized water presented greater Co ionic release than Steradent® (p=0.003). For Cr ions (p=0.000), Corega Tabs® had greater ionic release than deionized water, Steradent® and Polident 3 minutes®. Regarding Mo ions (p=0.001), Efferdent® showed greater release. With SEM, it was possible to verify that the solutions showed no deleterious effects on the specimen surfaces. It was concluded that no deleterious effects on metal surface was caused, however, Steradent® presented the smallest ionic release, and can be indicated more safely for cleaning metal surfaces of RPD.