Abstract Occlusal stabilization splints are the most common treatment for controlling the deleterious effects of sleep bruxism. This study aimed to evaluate the effectiveness of a low-cost, mixed occlusal splint (MOS) compared to that of a rigid splint. A randomized clinical trial was performed on 43 adults of both sexes with possible sleep bruxism and satisfactory dental conditions. They were divided into rigid occlusal splint (ROS) (n = 23) and MOS (n = 20) groups. Masticatory muscle and temporomandibular joint (TMJ) pain intensity (visual analog scale), quality of life (WHOQOL-BREF), indentations in the oral mucosa, anxiety, and depression (HADS), number of days of splint use, and splint wear were evaluated. All variables were evaluated at baseline (T0), 6 months (T6), and 12 months (T12) after splint installation (T0), and splint wear was evaluated at T6 and T12. Student’s t-test, Mann–Whitney U test, non-parametric Friedman’s analysis of variance for paired samples and pairwise multiple comparisons, Pearson’s chi-square test, two-proportion z-test, non-parametric McNemar’s and Cochran’s Q, and Wilcoxon tests were used (p < 0.05). In both groups, there was a decrease in TMJ pain and pain intensity over time and improvements in the quality of life scores. At T6, there was a higher rate of splint wear in the MOS group than in the ROS group (p = 0.023). The MOS showed a higher rate of wear than the rigid splint but had similar results for the other variables. Therefore, the use of a mixed splint appears to be effective in controlling the signs and symptoms of sleep bruxism. lowcost, lowcost low cost, cost low-cost (MOS 4 conditions (ROS n 23 20 groups (TMJ visual scale, scale , scale) WHOQOLBREF, WHOQOLBREF WHOQOL BREF (WHOQOL-BREF) mucosa anxiety HADS, HADS (HADS) T0, T0 T (T0) (T6) 1 T12 (T12 Students Student s ttest, ttest t test t-test MannWhitney Mann Whitney nonparametric non parametric Friedmans Friedman comparisons Pearsons Pearson chisquare chi square twoproportion two proportion ztest, ztest z z-test McNemars McNemar Cochrans Cochran Q p 0.05. 005 0.05 . 0 05 0.05) scores 0.023. 0023 0.023 023 0.023) Therefore 2 (WHOQOL-BREF (HADS (T0 (T6 T1 (T1 00 0.0 002 0.02 02 (T 0.

Resumo Objetivo Construir um protótipo virtual de um dispositivo de fixação circular externa para fraturas em ossos longos com dinamização controlada a partir de dois materiais diferentes e prever seu comportamento mecânico por meio da análise de elementos finitos AEF). Método Modelos tridimensionais compostos de duas peças metálicas unidas por uma junta deslizante em rabo de andorinha e um amortecedor de silicone de alta densidade foram criados em um software. Análises de elementos finitos distintas foram simuladas considerando dois materiais (aço inoxidável ou titânio), modos (bloqueado ou dinamizado) e condições de carregamento (estático/pontual ou dinâmico/0,5 segundo) diferentes com carga axial uniforme de 150 kg na porção superior do dispositivo. Resultados O modelo de elementos finitos (EFs) apresentou 81.872 nós e 45.922 elementos. Com aço inoxidável, o pico de tensão máxima (140,98 MPa) foi alcançado com o dispositivo bloqueado e sob carga estática, enquanto o maior deslocamento (2.415 × 10−3 mm) foi obtido com o dispositivo bloqueado e sob carga dinâmica. Com titânio, o pico de tensão máxima (141,45 MPa) ocorreu com o dispositivo bloqueado e sob carga estática, enquanto o maior deslocamento (3.975 × 10−3 mm) foi observado com o dispositivo bloqueado e sob carga dinâmica. Conclusão O protótipo do dispositivo desempenhou o papel de suporte de tensão com deformação aceitável nos dois modos, bloqueado ou dinamizado, e pode ser fabricado com aço inoxidável ou titânio.

Abstract Objective To virtually prototype a device for external circular fixation of long bone fractures with controlled dynamization made of two different materials and predict their mechanical behavior by using the finite element analysis (FEA) method. Method A software was used for 3D modeling two metal parts closely attached by a sliding dovetail joint and a high-density silicone damper. Distinctive FEAs were simulated by considering two different materials (stainless steel or titanium), modes (locked or dynamized) and loading conditions (static/point or dynamic/0.5 sec) with uniform 150 kg axial load on top of the device. Results The finite elements (FEs) model presented 81,872 nodes and 45,922 elements. Considering stainless steel, the maximum stress peak (140.98 MPa) was reached with the device locked under static loading, while the greatest displacement (2.415 × 10−3 mm) was observed with the device locked and under dynamic loading. Regarding titanium, the device presented the maximum stress peak (141.45 MPa) under static loading and with the device locked, while the greatest displacement (3.975 × 10−3 mm) was found with the device locked and under dynamic loading. Conclusion The prototyped device played the role of stress support with acceptable deformation in both locked and dynamized modes and may be fabricated with both stainless steel and titanium.

The aim of this study was to evaluate the effect of different peak wavelengths (450nm, 468nm and 490nm) of experimental LEDs on hardness, elastic modulus, degree of conversion and temperature rise of a microhybrid resin composite – Venus® (Heraeus Kulzer). Hardness and elastic modulus were determined by nanoindentation technique (n=5), degree of conversion was measured by FTIR (n=5) and temperature rise was measured with a thermistor (n=30). Data were submitted to ANOVA and multiple comparisons tests (α=0.05). Mechanical properties and degree of conversion (p<0.001) were superior on the top surfaces of the specimens. 468nm showed the highest mechanical properties values. There was no statistical difference in the degree of conversion (p=0.51) and in temperature rise (p=0.06) among all LEDs. Hardness and elastic modulus were influenced by LED´s wavelength, whereas degree of conversion and temperature rise were not influenced.

OBJETIVO: Este estudo avaliou as propriedades físicas de dois cimentos MTA disponíveis comercialmente. METODOLOGIA: A resistência a compressão (CS) dos materiais avaliados foi realizada após 21 horas e 14 dias de imersão em água. A avaliação da radiopacidade (RD) dos materiais foi mensurada em função de espessura de alumínio. Com relação à propriedade de tempo de presa (ST), tanto os tempos de presa inicial e final foram mensurados. A solubilidade foi calculada em função da percentagem de massa perdida após armazenamento em água. Os valores de pH foram mensurados em três diferentes tempos (inicial, 1 e 24 horas) de armazenamento em água. Todos os testes foram realizados de acordo com a norma ISO 6876-2:2001. RESULTADOS: Ambos os materiais apresentaram valores de CS e pH em acordo com os valores da norma ISO. Os dois cimentos apresentaram RD superiores ao limite de 3 mm de alumínio. Ambos os materiais mostraram resultados de SB inferiores ao limite de 3%. ST e pH também estão de acordo com a norma ISO 6876-2:2001. Adicionalmente foram avaliadas as superfícies dos materiais por MEV, e ambos apresentaram fases estruturais amorfas e cristalinas. CONCLUSÃO: Concluiu-se que ambos os materiais avaliados estão de acordo com as normas ISO, permitindo o seu uso como material de preenchimento de canais radiculares.

PURPOSE: This study evaluated some physical properties of two commercial MTA cements regarding it use as root canal filling material. METHODS: The compression strength (CS) of the evaluated materials was performed after 21 hours or 14 days of water immersion. The materials' radiopacity (RD) was measured according to aluminum thickness. Regarding setting time (ST), both initial and final times were measured. The solubility (SB) was calculated according to percentage of lost mass after water storage. The pH measurement was performed in three different times (initial, 1 and 24 hours) of water storage. All tests were performed according to ISO 6876-2:2001. RESULTS: Both cements showed that CS and pH were as in accordance with ISO standard. The two cements exhibited RD values higher than the equivalent limit of 3 mm-aluminum. Both materials exhibited SB values within the recommended limit of 3%. ST and pH also are in accordance with ISO 6876-2:2001. Additional SEM surface evaluation showed both amorphous and crystalline phase for both cements. CONCLUSION: It is possible to conclude that all evaluated materials are in accordance with ISO standard, allowing its use as root canal filling material.

Improvements in strength and setting time of Portland cements (PC) are needed to enhance their performance as endodontic and load bearing materials. This study sought to enhance the compressive strength and setting time of a PC by adding one of the following additives: 20% and 30% poly-methylmethacrylate (PMMA), 20% and 30% irregular and spherical amalgam alloys, and 10% CaCl2. The control consisted of unreinforced PC specimens. Setting time was determined using a Gillmore apparatus according to standardized methods while compressive strength was measured using a universal testing machine after 21 hours or 60 days of water storage. Data were analyzed by ANOVA, Tukey and Games-Howell tests (α = 5%). All additives significantly decreased both initial and final setting times as compared with the PC-control (p < .05). 30% PMMA and 30% irregular alloy had the lowest values of initial setting time. 30% irregular alloy also produced the lowest values of final setting time while 30% spherical alloy yielded the highest (p < .05). No differences were detected between the compressive strength values of 21 hours and 60 days. While 10% CaCl2, 20% and 30% PMMA produced values significantly lower than the PC-control, 30% spherical alloy significantly improved the compressive strength of the reinforced PC (p < .05). In summary, all additives significantly reduced the setting time and 30% spherical amalgam alloy yielded a significant increase in compressive strength for the tested PC, which might represent an improved composition for PCs to expand their use as endodontic and potentially load bearing materials.

A liberação de monômeros residuais pode afetar o comportamento clínico e a biocompatibilidade dos materiais resinosos. O objetivo deste estudo foi detectar e quantificar os principais monômeros residuais liberados de resinas compostas, usando cromatografia líquida de alta performance (HPLC). Discos foram construídos de resinas compostas de uso odontológico (Herculite XRV, Tetric Ceram and Filtek Z250) e imersos em água deionizada a 37ºC durante 28 dias, com mudanças de água em 24 horas, 7, 14 e 21 dias. As concentrações médias dos monômeros residuais foram submetidas ao teste de Kruskal-Wallis (p<0,05). Tetric Ceram apresentou as maiores concentrações de monômeros lixiviados. Bis-GMA foi o monômero liberado em menores concentrações para todos os materiais. Não houve diferença estatística significante entre TEGDMA e UDMA. A maioria dos monômeros demonstrou máxima concentração no período de 7 dias. A análise por meio de HPLC identificou Bis-GMA, TEGDMA e UDMA em quantidades detectáveis para todas as resinas compostas testadas.

The aim of this study was to detect and quantify the main residual monomers released from composites, using high performance liquid chromatography (HPLC). Discs were made with dental composites (Herculite XRV, Tetric Ceram and Filtek Z250) and immersed in deionized water at 37ºC for 28 days, with water changes in 1, 7, 14 and 21 days. The mean concentration of residual monomers were subject to the Kruskal-Wallis test (p<0.05). Tetric Ceram exhibited significantly higher concentrations of leached monomers. Bis-GMA was the monomer released in lower concentrations for all the materials. There was no statistical difference between the amounts of TEGDMA and UDMA. Most of the monomers demonstrated maximal concentration at the 7-day period. The HPLC analysis identified Bis-GMA, TEGDMA and UDMA in detectable quantities for all the tested composites.

O objetivo do presente estudo in vitro foi avaliar a dureza Knoop das resinas compostas, uma resina híbrida (Charisma - C) e uma de micropartículas (Durafill VS - D) quando polimerizadas à temperatura ambiente (A) (23 ± 1°C); refrigeradas (4 ± 1°C) e fotoativadas imediatamente após a remoção do refrigerador (0); e refrigeradas (4 ± 1°C), com tempo de espera de 15 min após a remoção do refrigerador para fotoativação (15). Cento e vinte corpos-de-prova com 4 mm de diâmetro por 2 mm de altura foram confeccionados em uma matriz de aço inoxidável. Cada corpo-de-prova foi testado imediatamente após a fotoativação (I) e, após 7 dias de armazenamento (7d) em ambiente escuro com umidade relativa a 100%, à temperatura do ambiente (23 ± 1°C). Quando testada imediatamente após a polimerização, na superfície de topo CAI foi estatisticamente semelhante à C15I e DAI à D15I. Na base, a resina composta CAI, teve maiores valores de dureza quando comparados à COI e C15I. Os grupos do material D não mostraram diferenças significantes com relação ao efeito da refrigeração na base. Sete dias após, os valores de dureza Knoop caíram tanto para C7d quanto para D7d com exceção de C07d que não diferiu de C07d nas diferentes superfícies, e D07d que mostrou maiores valores de dureza no topo.

This in vitro study evaluated the Knoop hardness of the composite resins Charisma® (C) and Durafill VS® (D) polymerized in 3 different conditions: at room temperature (A) (23 ± 1°C); refrigerated at 4 ± 1°C and immediately photo-activated after removal from the refrigerator (0); and, refrigerated at 4 ± 1°C and photo-activated after a bench time of 15 min at room temperature (15). One hundred and twenty specimens (4 mm diameter and 2 mm depth) were made using a stainless steel mold and following manufacturer's instructions. All specimens were tested immediately after polymerization (I) and after 7 days of water storage in the dark at room temperature (7d). The data were subjected to ANOVA and post-hoc Tukey's test (a=0.05). On the top surface, CAI was statistically similar to C15I and DAI to D15I (p>0.05). On the bottom surface, CAI presented higher hardness values when compared to COI and C15I (p<0.05). The D groups showed no significant differences (p>0.05) on the bottom surfaces for any tested polymerization condition. After 7 days of storage, the Knoop hardness decreased significantly (p<0.05) for groups C7d and D7d except for C07d, which was not different from COI at either surface (p>0.05). D07d showed higher Knoop hardness (p<0.05) values on the top surface when compared to the other groups.

A alta prevalência da candidose em usuários de prótese dental removível e a sua terapêutica com agentes antifúngicos (AA) está estabelecida. Contudo, o efeito dos AA sobre a superfície da resina de poli(metil-metacrilato) (PMMA) ainda não foi estudada. Assim, objetivou-se avaliar o efeito do fluconazol (FLU), nistatina (NYS) e gel orabase de própolis (GO) sobre a superfície de PMMA. Água deionizada e GO sem princípio ativo foram utilizadas como controles. Espécimes fabricados com PMMA polimerizada em banho de água ou com energia de microondas receberam acabamento e polimento e tiveram a rugosidade de superfície (RS), energia livre de superfície (ELS) e dureza Knoop (DK) mensuradas. Os tratamentos de superfície foram obtidos pela imersão dos espécimes nos AA durante 14 dias. Os resultados obtidos foram analisados por ANOVA para dois fatores e para a comparação, entre tratamentos e resinas, o teste de Tukey (α=0,05) foi utilizado. Os resultados mostraram que ambas as resinas aumentaram RS e ELS, mas não diferiram entre si (p>0,05). Os grupos tratados com própolis mostraram valores maiores de RS e diferente dos demais AAs (p<0,05). Com relação a rugosidade e energia livre de superfície não foram encontradas diferenças entre as PMMAs e entre FLU e NYS. Concluiu-se que a própolis induziu modificações na superfície de PMMA aumentando a rugosidade, fator que poderá facilitar a adesão de microrganismos.

The prevalence of candidosis in denture wearers is as well established as its treatment with antifungal agents (AAs). However, little research has been done regarding the effects of AAs on denture base surfaces. Therefore, the aim of this study was to evaluate the effects of fluconazole (FLU), nystatin (NYS) and propolis orabase gel (PRO) on poly (methyl-methacrylate) (PMMA) surfaces. Deionized water and orabase gel without any active component were used as control groups. Conventional heat-polymerized (Clássico) and microwave-polymerized (Onda Cryl) acrylic resins were used. After polymerization, the specimens were polished and had their surfaces evaluated for roughness, free energy and Knoop hardness. Subsequently, specimens were immersed in AAs and controls for 14 days at 35±2 °C and all variables were measured again. Data were analyzed statistically by 2-way ANOVA followed by Tukey's test ( α=0.05). Roughness results showed similar behavior for both PMMA resins, with PRO reaching the highest values and differing significantly from the other AAs (p<0.05). No statistically significant differences (p>0.05) were found between the two PMMA resins or between NYS and FLU as regards surface free energy. In conclusion, PRO was able to induce changes in PMMA surface properties, such as roughness, which could be related to microbial adhesion.