PROPOSIÇÃO: Avaliar o comportamento dimensional e rugosidade superficial de modelos de gesso tipos III e IV, obtidos em moldes de hidrocolóide irreversível desinfetados com vapor de hipoclorito de sódio 5,25%. METODOLOGIA: Os moldes para obtenção dos modelos de gesso tipo III e tipo IV foram designados: Grupo 1 (desinfecção com vapor de hipoclorito de sódio 5,25% por 10 minutos); Grupo 2 (simulação de desinfecção com vapor de água destilada) e Grupo 3 (sem tratamento). Para medição das alterações dimensionais, moldou-se modelo mestre de aço inox com quatro pilares e confeccionou-se 36 modelos (18 para cada tipo de gesso) e as distâncias foram mensuradas com paquímetro digital. Para leitura da rugosidade, confeccionaram-se 36 modelos a partir de moldes de plataforma de aço inox polida e avaliou-se a superfície dos gessos com rugosímetro. Os dados foram submetidos à análise de variância e teste de Tukey (α=1%). RESULTADOS: Na medição das dimensões lineares entre pilares e leitura da rugosidade superficial, não houve diferença estatística significativa, quando comparados os tipos de tratamento (Grupos 1, 2 e 3) em nenhum dos tipos de gesso. CONCLUSÃO: Os tratamentos dos moldes de hidrocolóide irreversível com vapor de hipoclorito de sódio e água destilada não afetaram significantemente a estabilidade dimensional e a rugosidade superficial dos modelos de gesso tipo III e tipo IV.

PURPOSE: To evaluate the surface roughness and dimensional stability of types III and IV gypsum models, obtained from irreversible hydrocolloid impressions after disinfection with 5.25% sodium hypochlorite steam. METHODS: The impressions to obtain type III and type IV gypsum models were divided into 3 groups: Group 1 (disinfection with 5.25% sodium hypochlorite steam for 10 minutes); Group 2 (simulated disinfection with distilled water steam) and Group 3 (no treatment). To measure the dimensional changes with a digital caliper, 36 models (18 for each type of gypsum) were cast according to a stainless steel master model with four pillars. For the surface roughness measurement, 36 gypsum models were cast from the impressions of the polished stainless steel platform. The data were analyzed using ANOVA and Tukey's test (α=1%). RESULTS: There was no statistically significant difference in linear dimensions or surface roughness when the different disinfection treatments were compared (Groups 1, 2 and 3), for all types of gypsum. CONCLUSION: The disinfection treatments with sodium hypochlorite steam and distilled water steam for irreversible hydrocolloid impressions did not significantly affect the dimensional stability and surface roughness of the types III and IV gypsum dental models.

OBJETIVO: avaliar a eficácia antimicrobiana do vapor de hipoclorito de sódio 2,5% e 5,25% na desinfecção de moldes de hidrocolóide irreversível em Caixa Umidificadora e Caixa Nebulizadora. METODOLOGIA: Utilizaram-se 80 moldes de hemiarcos de pacientes, distribuídos em 4 grupos experimentais de 20 amostras cada, com respectivos controles. Os moldes permaneceram 10 min em atmosfera de hipoclorito de sódio com 100% de umidade relativa. Após desinfecção, cada molde foi imerso em soro fisiológico sob vibração ultrassônica e a análise microbiológica dessa solução foi realizada pela contagem de colônias que cresceram em meio de cultura BHI-ágar após 24h em estufa incubadora a 37ºC. Os dados foram analisados pelo teste t de Wilcoxon. RESULTADOS: Em todos os grupos observou-se maior número médio de colônias dos grupos controles em relação aos experimentais (P<0,0001). Para 2,5% de hipoclorito de sódio houve diferença estatística significativa entre Caixa Nebulizadora e Caixa Umidificadora. A concentração 5,25% não demonstrou diferença estatística entre os números médios de colônias nos dois métodos utilizados (P>0,01). CONCLUSÃO: Hipoclorito de sódio 5,25% poderá ser utilizado para desinfecção nos métodos Caixa Umidificadora e Caixa Nebulizadora, no entanto, a concentração 2,5%, só será eficaz quando utilizada no método Caixa Nebulizadora.

PURPOSE: To evaluate the antimicrobial effectiveness of 2.5% and 5.25% sodium hypochlorite steam to disinfect an irreversible hydrocolloid impressions in Humidifier and Nebulizer Boxes. METHODS: The study used a total of 80 quadrant impressions of patients, divided into 4 experimental groups of 20 samples each, with respective controls. The impressions were placed in an atmosphere of sodium hypochlorite with 100% relative humidity for 10 min. After disinfection, each impression was immersed in saline solution that was ultrasonically vibrated. Microbiological analysis of the solution was carried out by counting colonies grown in BHI-agar culture medium after 24 hours in an incubator at 37ºC. The data were analyzed using Wilcoxon's t test. RESULTS: In all groups, it was found that the mean number of colonies in control groups was higher then in the experimental groups (P<0.0001). There was a significant difference between using the Nebulizer Box and the Humidifier Box when 2.5% sodium hypochlorite was used. At a concentration of 5.25% there was no statistical difference between the mean numbers of colonies for the two methods (P>0.01). CONCLUSION: Sodium hypochlorite at 5.25% can be used for disinfection in the Humidifier Box and Nebulizer Box methods. However, at a 2.5% concentration it is only effective in the Nebulizer box method.

Intramucosal inserts made of zirconia ceramic have been used for the rehabilitation of edentulous patients. This study aimed to follow up on patients with complete dentures having intramucosal zirconia inserts and to perform a histological analysis of biopsies of the epithelium surrounding the inserts. Twelve 31-66-year-old subjects of both genders received complete denture treatment having the intramucosal inserts in place. Detailed clinical, prosthetic and surgical procedures were described. Clinical exams were done on postoperative days 3, 7, 15, 120 and 360. One year after denture placement, the subjects received local anesthesia and the tissues surrounding the insertion sites in the alveolar ridge were removed using a scalpel blade. Biopsies were fixed for up to 48 h in 10% phosphate-buffered formaldehyde and 5-µm-thick sections were cut and stained with hematoxylin and eosin and Gomori Trichrome. Immunohistochemistry was used to identify endothelium (anti-CD3) and T lymphocytes (anti-CD31). Removing and reinserting the denture was painful until day 15, but all patients reported a marked increase in the retention and stability of the complete denture with little or no discomfort after 30 days. The histopathological analysis showed that zirconia inserts were well tolerated by the oral mucosa, with the presence of collagen fibers in the tissue around the insert, with mild inflammatory response and allowing reepithelialization, expressed by parakeratosis, epithelial hyperplasia and presenting granular layer. In conclusion, intramucosal zirconia inserts did not affect the health of oral mucosa and provide adequate retention and stability of the complete denture and comfort to the patients.