Objective: This study verified the surface microroughness of denture acrylic resins submitted to toothbrushing, chemical disinfection and thermocycling procedures. Material and methods: Samples were prepared according to conventional, microwaved and boiled resins and submitted to microroughness measurements before and after procedures using a profilometer (Ra). Data were subjected to ANOVA and Tukey's test (5%). Results: Before thermocycling, a difference was found among treatments for microwaved and boiled resins, with greater values for toothbrushing and lower values for Efferdent and hypochlorite; control was intermediate. Differences among resins were observed for treatments, with higher values for boiled resin and lower values for conventional and microwaved resins. After thermocycling, differences were found for microwaved resin, with a higher value for toothbrushing and a lower value for Efferdent and hypochlorite; control was intermediate. Tooth-brushed boiled resin presented higher values and hypochlorite lower values; control and Efferdent were intermediates. Differences among resins were seen for treatments, with higher values for boiled resin and lower values for conventional and microwaved resins. Boiled resin presented differences for toothbrushing and hypochlorite, before and after thermocycling procedures were compared. Conclusions: For microwaved and boiled resins, toothbrushing and chemical disinfection promoted different levels of surface microroughness when associated or not with thermocycling.

Traditional clamp and immediate post-pressing time improved base adaptation for conventional heat-cure resin.

The purpose of this study was to characterize the linear dimensional change in specimens made in aluminum rectangular dies (65.0x12.0x3.5mm), with 4 reference demarcations, using the Clássico, Onda-Cryl and QC-20 brands of acrylic resin. Wax patterns with 67.0x15.0x5.0mm were embedded in metallic or plastic flasks with stone gypsum, according to the conventional technique. After stone gypsum setting, the wax molds were removed and the aluminum dies impressed in the stone gypsum mold with silicone material. The powder/liquid proportion and acrylic resin were manipulated according to manufacturer’s instructions. The metallic flask pressure was achieved using the RS tension method. After polymerization in water at 74OC for 9 hours, ebullition water for 20 minutes or microwave energy (900 W) for 10 minutes, the specimens were cooled at room temperature and then removed from the flasks and submitted to conventional finishing. The distances between the A-B, C-D, A-C, and B-D reference points were measured before and after disinfection by microwave energy (650W for 3 minutes). The linear dimensional evaluation of the distances was performed by the same operator with an Olympus optical comparator microscope, with an accuracy of 0.0005mm. Obtained data were submitted to ANOVA and Tukey’s test (α=.05%). The disinfection by microwave energy did not alter the original linear dimensions of the specimens.

Esse trabalho avaliou o efeito de agentes de limpeza sobre as características superficiais de materiais resilientes. Foram utilizados os materiais Luci Sof (Dentsply), Molloplast-B (Dentax) e Sofreliner (Tokuyama), e os agentes de limpezaHipoclorito de Sódio a 0,5% (Medicinallis - Farmácia de Manipulação) e Efferdent (Warner-Lamber Co). Foram confeccionados 20 corpos de prova de cada material. Os agentes de limpeza foram utilizados da seguinte maneira: 1) Hipoclorito de sódio a 0,5% (HA) a 37 ± 1 ºC, durante 20 min; 2) Peróxido Alcalino (PA) a 37 ±1 ºC, durante 15 min. Após as imersões,os corpos de prova foram lavados e imersos em água destilada a 37 ±1 ºC pelo período restante das 24 h (8x ao dia, durante 90 dias). A rugosidade superficial foi avaliada em rugosímetro Surfcorder SE 1700 (Kosaka- Laboratory Ltda),após 0 (T1), 180 (T2), 360 (T3) e 720 (T4) ciclos de higienização. Os resultados foram submetidos à ANOVA e teste de Tukey (5%). Para a imersão em HA, Luci Sof apresentou redução significativa dos valores de rugosidade superficial em T2, T3 e T4; e o material Sofreliner, em todos os tempos. Para a imersão em PA, Luci Sof apresentou redução significativa dos valores em T2, T3 e T4; Molloplast-B, redução significativa em T3; Sofreliner, aumento significativo em T4. Concluiu-se que a imersão em agentes químicos de limpeza, em geral, reduz a rugosidade superficial de reembasadores resilientes. Molloplast-B apresentou comportamento linear durante o estudo. Sofreliner, imerso em Hipoclorito, apresentou valores de rugosidade inferiores ao considerado mínimo para retenção bacteriana.

The aim of this study is to investigate the effect of the toothbrushing, chemical disinfection and thermocycling treatments on the surface hardness of acrylic resins used for denture bases. The Classico (conventional), Onda Cryl (microwaved) and QC-20 (boiled) thermoactivated acrylic resins were used to prepare specimens. Prior to and after cleaning procedures, the specimens were submitted to a hardness test in an indenter (HMV-2000 Shimadzu), employing a load of 50 gf for 10 s. Three-way ANOVA and Tukey's test (α=0.05) were used to analyze the data. Prior to thermocycling, statistical differences were found among treatments for Onda Cryl, with greater hardness values observed for Efferdent and hypochlorite; lower hardness value was obtained after toothbrushing, and intermediate value was found for the control. Differences were found among resins for the control treatment, with higher value for QC-20 resin, lower value for the Classico, and intermediate value for the Onda Cryl. Following thermocycling, differences were observed among treatments for Onda Cryl, with control specimens presenting higher values, lower value for toothbrushing and intermediate values for Efferdent and hypochlorite. Differences were also found for QC-20, with Efferdent and hypochlorite presenting higher values, lower value for control and intermediate value for toothbrushing. Differences were found among resins for the control treatment, with higher value for Onda Cryl resin, lower value for the QC-20, and intermediate value for the Classico. The QC-20 resin showed higher value for control prior to thermocycling and Onda Cryl after thermocycling. Different effects on the surface hardness of acrylic resins used for denture bases were observed when associating thermocycling with toothbrushing or chemical disinfections.

No abstract

The aim of this study was to describe a clinical protocol for fabrication of maxillary and mandibular dentures using CAD/CAM technology. Further, digital and conventional dentures fabricated for the same patient were compared. The comparison was based on patient’s satisfaction, comfort, retention, number of follow-up sessions, masticatory performance and quality of life. No laboratorial step was needed for CAD/CAM fabrication and less sessions were required up to denture insertion. Compared to the conventional dentures, digital dentures provided better satisfaction, comfort and retention and required less follow-up sessions. Both dentures presented similar results about masticatory performance and quality of life. As a conclusion, digital denture is a viable treatment alternative for edentulous patients. However, controlled and randomized clinical trials are required to reveal the real benefits of this treatment alternative compared to the conventional denture.

A Odontologia estética está em evidência na atualidade, sendo assim, cada vez mais pessoas buscam por reabilitações orais para suprir exigências pessoais e sociais de beleza ideal do sorriso. Dessa forma, avanços na qualidade dos materiais restauradoras além de novas técnicas de moldagem, como uso do escâner digital, foram apresentados e discutidos. O propósito desse artigo foi descrever um relato de caso clínico de reabilitação oral com laminados do sistema cerâmico IPS E.max, associado ao uso de escaneamento digital. Uma paciente do gênero feminino procurou atendimento odontológico com interesse de restabelecer a harmonia do incisivos centrais e laterais, por insatisfação com as restaurações antigas. Foram analisadas as suas queixas e expectativas e proposto um planejamento, além de registro fotográfico, moldagem dos arcos, montagem em articulador semi-ajustável, planejamento digital do sorriso e o encaminhamento ao laboratório para confecção do enceramento diagnóstico, que auxiliou na etapa de mock-up. Os dentes foram preparados e submetidos à impressão óptica por um escâner especial Bluecam da CEREC Sistema CAD / CAM (desenho assistido por computador / manufatura assistida por computador). Os laminados de dissilicato de lítio (IPS E.max) foram cimentados com cimento resinoso fotopolimerizável na cor translúcida. Conclui-se que um planejamento apropriado ocorre desde um bom diagnóstico, preparos dentários e uma boa técnica de moldagem. Além disso, o uso do escâner digital é um recurso que pode auxiliar no sucesso do tratamento reabilitador com o uso do sistema IPS E.max.