Surface Roughness Changes in Denture Liners in Denture Stomatitis Patients.

PURPOSE: This randomized clinical trial assessed how surface roughness (Ra) in resilient liners was affected by soft tissue health conditions and time-related aspects in patients with complete dentures. METHODS: Specimens of acrylic resin (control) and denture liners (silicone-based or acrylic resin-based) were inserted into the dentures of patients with and without denture stomatitis (n = 30). Ra was evaluated before denture insertion and after 7, 14, and 21 days of prosthesis wearing. Data were analyzed using three-way analysis of variance and Student-Newman-Keuls test. RESULTS: Patients with stomatitis showed a higher Ra (P < .001), while all liners presented rougher surfaces after 14 days of clinical service, irrespective of the soft tissue health condition. CONCLUSION: Ra of the tested denture liners was increased in patients with denture stomatitis. It is presumed that a longer wearing period will result in rougher surfaces.

Ceramic Repair Without Hydrofluoric Acid.

PURPOSE: To evaluate the bond strength between composite resin and feldspathic ceramic following repair protocols with and without hydrofluoric acid and aging by thermocycling. MATERIALS AND METHODS: Forty-eight glass feldspathic ceramic blocks (8 x 8 x 6 mm) were divided into three groups on the basis of their surface repair treatment: 1. 10% hydrofluoric acid + Signum Ceramic Primer I + Signum Ceramic Primer II (control group); 2. abrasive rubber tips + Signum Ceramic Primer I + Signum Ceramic Primer II (test group); 3. Signum Ceramic Primer I + Signum Ceramic Primer II (negative control group). The treated surface of each block was built up with composite and then sectioned to produce nontrimmed bars (adhesive area = 1 mm²). Half of the bars from each group were aged by 6000 cycles of 30-s immersions in water baths at 5°C and 55°C, with a transfer time of 2 s. The other bars were immediately subjected to microtensile bond strength testing. The mean bond strength for each block was then recorded and submitted to two-way ANOVA and Tukey's test (α = 0.05). RESULTS: The aging protocol influenced the bond strength values of all groups (p = 0.000). The non-aged groups submitted to surface treatment protocols 1 (13.1 ± 2.5 MPa) and 2 (11.5 ± 5.1 MPa) presented the highest bond strength values. CONCLUSIONS: The interface bond strength of all groups was susceptible to aging. Surface treatment protocol 2, with abrasive rubber tips and no hydrofluoric acid, appeared to be the most promising option, as the resulting bond strength values were similar to those of the control group.

Importância do enceramento diagnóstico na reabilitação estética e funcional / The diagnostic wax-up as an important tool in the aesthetic and functional rehabilitation

Restaurações à base de resina composta direta têm mostrado boas taxas de longevidade, no entanto, apresentam comprometimento estético ao longo do tempo. Para suprir essa carência, as restaurações cerâmicas têm se tornado uma ótima opção de tratamento para dentes anteriores, sendo a cerâmica feldspática a que apresenta melhores propriedades estéticas e capacidade de reprodução de detalhes. Assim, este artigo procurou descrever a confecção de quatro laminados cerâmicos, à base de cerâmica feldspática, para restauração de incisivos superiores, inicialmente restaurados com restaurações insatisfatórias em resina composta. Após a conclusão da reabilitação, foi possível concluir que o tratamento restabeleceu satisfatoriamente a estética e a função da paciente.

Resin composite restorations show good survival rates; however, they present esthetic problems after longer clinical periods. For this, ceramic restorations are a good alternative and feldspathic ceramics present the best esthetic properties. This article describes the fabrication of four laminate veneers with feldspathic ceramics to restore the maxillary incisors with unsatisfactory composite restorations. Good levels of esthetic and function were achieved at case conclusion.

Biofilm formation on denture liners in a randomised controlled in situ trial.

OBJECTIVES: This randomised clinical trial assessed how biofilm development and composition is affected by time and denture material type in denture wearers with and without denture stomatitis. METHODS: Specimens of acrylic resin (control) and denture liners (silicone-based or acrylic resin based, depending on the experimental phase) were inserted into the surface intaglio of 30 denture wearers. Biofilm was formed in two phases of 21 days, and counts of viable micro-organisms in the accumulating biofilm were determined after 7, 14 and 21 days of biofilm formation. Data were analysed by three-way ANOVA followed by Tukey test to assess differences among health condition (healthy or with denture stomatitis), materials and time point. RESULTS: Non-albicans Candida species counts were higher in diseased patients with silicone-based denture liners (p=0.01). Denture stomatitis patients showed higher mutans streptococci counts after 7 days (p=0.0041). CONCLUSIONS: Longer biofilm formation time periods did not result in differences on biofilm composition. The denture liners evaluated in this study accumulate greater amount of biofilm, and therefore their use should be carefully planned. CLINICAL SIGNIFICANCE: The silicone-based denture liner tested should be used cautiously in patients with denture stomatitis as it showed increased non-albicans species counts, known to be difficult to treat.