Niobium oxyhydroxide as a bioactive agent and reinforcement to a high-viscosity bulk-fill resin composite

Abstract Objective The present in vitro study incorporated niobium oxyhydroxide fillers into an experimental high-viscosity bulk-fill resin composite to improve its mechanical performance and provide it a bioactive potential. Methodology Scanning electron microscopy synthesized and characterized 0.5% niobium oxyhydroxide fillers, demonstrating a homogeneous morphology that represented a reinforcement for the feature. Fillers were weighed, gradually added to the experimental resin composite, and homogenized for one minute, forming three groups: BF (experimental high-viscosity bulk-fill resin composite; control), BF0.5 (experimental high-viscosity bulk-fill resin composite modified with 0.5% niobium oxyhydroxide fillers), and BFC (commercial bulk-fill resin composite Beautifil Bulk U, Shofu; positive control). In total, 10 specimens/groups (8 × 2 × 2 mm) underwent flexural strength (FS) tests in a universal testing machine (Instron) (500N). Resin composites were also assessed for Knoop hardness (KH), depth of cure (DoC), degree of conversion (DC), elastic modulus (E), and degree of color change (ΔE). The bioactive potential of the developed resin composite was evaluated after immersing the specimens into a simulated body fluid in vitro solution and assessing them using a Fourier-transformed infrared spectroscope with an attenuated total reflectance accessory. One-way ANOVA, followed by the Tukey's test (p<0.05), determined FS, DC, KH, and ΔE. For DoC, ANOVA was performed, which demonstrated no significant difference between groups (p<0.05). Conclusions The high-viscosity bulk-fill resin composite with 0.5% niobium oxyhydroxide fillers showed promising outcomes as reinforcement agents and performed well for bioactive potential, although less predictable than the commercial resin composite with Giomer technology.

Abordagem conservadora de lesões cariosas profundas: uma revisão de literatura / Conservative approach to deep carious lesions: a literature review

O presente trabalho tem como objetivo realizar uma revisão de literatura e discutir os mais atuais conceitos sobre abordagem conservadora de lesões cariosas profundas, facilitando o manejo clínico. Para que essa abordagem conservadora seja implementada, é imprescindível que se conheça a composição estrutural e funcional do biofilme para, assim, entender a evolução da doença cárie que acomete a estrutura dentária. No entanto, quando se trata de um dente com lesão de cárie ativa com grande comprometimento de esmalte e dentina, procedimentos operatórios mais invasivos e restauradores podem ser necessários, mesmo que fundamentados na maior preservação possível de estrutura dentária. As evidências mais atuais encontradas na literatura recomendam a remoção seletiva do tecido cariado que consiste na dentina infectada, ou seja, clinicamente amolecida, e restauração definitiva na mesma sessão. Portanto, desde que o dente apresente vitalidade pulpar clinicamente confirmada, acredita-se que a preservação estratégica da dentina, poderá aumentar as chances de sucesso no tratamento, evitando possível exposição da polpa dentária. Adicionalmente, ao optar por práticas conservadoras no contexto da Odontologia de mínima intervenção, resultará em um significativo aumento na longevidade das restaurações sempre associando promoção de saúde ao paciente(AU)

This paper aims to conduct a literature review and discuss the most current concepts on conservative approach to deep carious lesions in permanent posterior teeth, facilitating clinical management. For this conservative approach to be implemented, it is essential to know the structural and functional composition of the biofilm in order to understand the evolution of the caries disease that affects the dental structure. However, when it comes to a tooth with an active caries lesion with major enamel and dentin compromise, more invasive and restorative surgical procedures may be necessary, even if based on the greatest possible preservation of the dental structure. The most current findings in the literature recommend the selective removal of carious tissue consisting of infected dentin, that is, clinically softened, and definitive restoration in the same session. Therefore, as long as the tooth has clinically confirmed pulp vitality, it is believed that the strategic preservation of dentin may increase the chances of successful treatment, avoiding possible exposure of the dental pulp. Additionally, when opting for conservative practices in the context of Minimally Invasive Dentistry, it will result in a significant increase in the longevity of restorations, always associating health promotion to the patient(AU)

Giomer technology for preventive and restorative clinical management of erosive tooth wear: a case report / Tecnologia Giomer para manejo clínico preventivo e restaurador de desgaste dentário erosive: relato de caso

Increasing prevalence of erosive tooth wear (ETW) is notable mainly due to current knowledge and its early diagnosis. Once teeth are functionally and/or esthetically affected, dental restorations may become necessary. Materials capable of interacting with the eroded dental tissue allied to their resistance to subsequent continuous erosive challenges are desirable. Giomer technology based on S-PRG (surface pre-reactive glass) filler has been launching to provide benefits for the dental treatment due to its innovative multi-ionic release system, which involves fluoride. This case report describes the employment of preventive and restorative materials based on this technology for a patient under frequent erosive challenges and complaining about dental sensitivity. Patient reported immediate reduction on this sensitivity and the restorations has been followed up for 2 years, presenting satisfactory performance. S-PRG-based systems seem to be promissory for preventive and therapeutic management of ETW used simultaneously with the patient compliance. (AU)

O aumento da prevalência do desgaste dentário erosivo (DDE) é notável especialmente devido ao conhecimento atual e seu diagnóstico precoce. Uma vez que os dentes são afetados funcional e/ou esteticamente, restaurações dentárias se tornam necessárias. Materiais focados na habilidade de interagir com o tecido dentário erodido associados com sua resistência aos desafios erosivos contínuos subsequentes são desejáveis. A tecnologia Giomer baseada em partículas S-PRG (superfície de vidro pré-reativo) foi lançada no mercado para oferecer benefícios para o tratamento odontológico devido ao seu sistema inovador de liberação multi-iônica, que envolve o flúor. Esse caso clínico descreve o uso de materiais preventivo e restaurador baseados nessa tecnologia em um paciente em desafio erosivo e com queixa de sensibilidade. O paciente relatou redução imediata da sensibilidade e as restaurações foram acompanhadas por 2 anos apresentando desempenho satisfatório. Sistemas baseados em S-PRG se mostram promissores para manejo preventivo e terapêutico do DDE empregados simultaneamente à colaboração do paciente.(AU)

Efeito de diferentes protocolos fotoativadores e espessura dos incrementos na dureza de resinas Bulk fill / Effect of lightcure protocols and increment thickness in the hardness of Bulk fill composites

As resinas Bulk fill surgiram com o intuito de facilitar a restauração de cavidades profundas. A fotoativação adequada é extremamente importante para que a resina bulk fill ofereça propriedades mecânicas satisfatórias e, longevidade na restauração. Este estudo avaliou a influência da espessura do incremento na microdureza Knoop (KHN) de três resinas bulk fill (n = 5). Cinquenta amostras foram divididas de acordo com o material (Filtek Z250, Filtek One Bulk Fill e Filtek Bulk Fill Flow), espessura (2mm e 4 mm) e tempo de fotoativação (20 e 40s) - Z2502mm20s, Z2502mm40s, One2mm20s, One2mm40s, One4mm20s, One4mm40s, Flow2mm20s, Flow2mm40s, Flow4mm20s e Flow4mm40s. As análises KHN foram realizadas no topo e na base de cada amostra. Os dados foram submetidos à ANOVA a 1 critério e ao Teste de Tukey (p< 0,05). A média e desvio padrão (+/-) dos seguintes grupos foram (Z2502mm20s) 0,85 (+/- 0,01); (Z2502mm40s) 0,92 (+/- 0,01); (One2mm20s) 1,05 (+/- 0,08); (One2mm40s) 0,95 (+/- 0,04); (One4mm20s) 0,93 (+/- 0,04); (One4mm40s) 0,97 (+/ - 0,04); (Flow2mm20s) 0,92 (+/- 0,05); (Flow2mm40s) 0,89 (+/- 0,04); (Flow4mm20s) 0,79 (+/- 0,04) e (Flow4mm40s) 0,90 (+/- 0,03). Os grupos da Filtek One Bulk apresentaram um valor significativamente maior, demonstrando uma polimerização suficiente mesmo na base de incrementos com 4 mm. Concluiu-se que o aumento na espessura do incremento de resinas bulk fill não afetou negativamente a fotoativação(AU)

Bulk fill composites emerged, allowing the restoration of deep cavities easily. Appropriate lightcuring is crucial to bulk fill composite presents satisfactory mechanical properties and restoration longevity. This study evaluated the influence of thickness increment on Knoop microhardness (KHN) of three dental bulk fill composites (n=5). Fifty samples were divided according to composite (Filtek Z250, Filtek One Bulk Fill and Filtek Bulk Fill Flow), thickness (2mm and 4 mm) and time lightcuring (20 and 40 s) - Z2502mm20s, Z2502mm40s, One2mm20s, One2mm40s, One4mm20s, One4mm40s, Flow2mm20s, Flow2mm40s, Flow4mm20s e Flow4mm40s. KHN analysis were performed on the top and the base of each specimen. Data were subjected to one-way ANOVA and Tukey test (p< 0,05). The mean and standard deviation (+/-) of following groups were (Z2502mm20s) 0,85(+/-0,01); (Z2502mm40s) 0,92(+/- 0,01); (One2mm20s) 1,05(+/-0,08); (One2mm40s) 0,95(+/-0,04); (One4mm20s) 0,93 (+/-0,04); (One4mm40s) 0,97(+/-0,04); (Flow2mm20s) 0,92(+/- 0,05); (Flow2mm40s) 0,89(+/-0,04); (Flow4mm20s) 0,79(+/-0,04) e (Flow4mm40s) 0,90(+/-0,03) Filtek One Bulk groups present significantly higher value, demonstrating sufficient polymerization even on the base of 4 mm increments. It was concluded that the increase in the thickness increment of Bulk fill composites did not negatively affect the lightcure(AU)

Effect of a resin-modified glass-ionomer with calcium on enamel demineralization inhibition: an in vitro study

Abstract We assessed the effect of a new coating material based on resin-modified glass-ionomer with calcium (Ca) in inhibiting the demineralization of underlying and adjacent areas surrounding caries-like lesions in enamel. The measures used were surface hardness (SH) and cross-sectional hardness (CSH). Thirty-six bovine enamel specimens (3 × 6 × 2 mm) were randomly allocated into three groups (n = 12): No treatment (NT); resin-modified glass-ionomer with Ca (Clinpro XT Varnish, 3M ESPE) (CL), and fluoride varnish (Duraphat, Colgate) (DU). The specimens were subjected to alternated immersions in demineralizing (6 h) and remineralizing solutions (18 h) for 7 days. SH measurements were conducted at standard distances of 150, 300, and 450 µm from the treatment area. CSH evaluated the mean hardness profile over the depth of the enamel surface and at standard distances from the materials. The energy-dispersive X-ray spectroscopy analysis was conducted to evaluate the demineralization bands created on the sublayer by % of calcium (Ca), phosphorus (P), and fluoride (F). Ca/P weight ratio was also calculated. Based on SH and CSH measurements, there was no difference between groups at the distances 150 µm (p = 0.882), 300 µm (p = 0.995), and 450 µm (p = 0.998). Up to 50 µm depth (at 150 µm from the treatment area), CL showed better performance than DU ( p< 0.05). NT presented higher loss of Ca and P than CL and DU (p < 0.05). There was no significant difference in the % of F ion among the three groups. The new coating material was similar to F varnish in attenuating enamel demineralization.

Understanding the interaction of resin composite with light for predictable aesthetic results in anterior teeth: A case report / Compreensão da interação das resinas compostas com a luz para resultados estéticos previsíveis em dentes anteriores: Relato de caso

This case report illustrates a conservative technique for reintervention on anterior composite restorations in a young patient with composite veneers. The treatment incorporated the use of photos and digital planning to establish a harmonious smile design. In order to conserve the dental tissues, existing resin composites restorations in maxillary anterior teeth were carefully removed to minimize enamel reduction, followed by a study of color and shade of teeth considering factors such as hue, chroma, luminosity, opacity, translucency and light effects. Eight direct veneers were built up with resin composite taking the optical properties of the material into account and their influence on the thickness of the layers that create specific light effects when superimposed on each other. To obtain excellent results with a predictable working protocol, nanohybrid composite systems facilitate good aesthetics, avoiding more invasive treatment in an economic manner.(AU)

O presente relato de caso ilustra uma técnica conservadora para a re-intervenção em restaurações diretas de resina composta em pacientes jovens. O tratamento consistiu em fotos e planejamento digital para obtenção de um desenho digital do sorriso individual e harmonioso. De acordo com os princípios de máxima conservação da estrutura dentária, as restaurações existentes nos dentes superiores anteriores foram criteriosamente removidas para minimizar a redução do esmalte, seguido do estudo de cor e sombra dos dentes considerando fatores como matiz, croma, valor, opacidade, translucidez e efeitos de luz. Oito facetas diretas foram realizadas em resina composta considerando as propriedades ópticas do material e a influência destas na espessura das camadas de resina para criar efeitos de luz singulares quando sobrepostas. Para a execução de uma odontologia estética e consciente, em associação a um protocolo de trabalho previsível, os sistemas de resinas compostas nanohibridas possibilitam resultados estéticos satisfatórios, evitando tratamentos mais invasivos de maneira economicamente viável.(AU)

Pulp Chamber Heating: An In Vitro Study Evaluating Different Light Sources and Resin Composite Layers

Abstract The aim of the present in vitro study was to evaluate the temperature variation inside the pulp chamber during light-activation of the adhesive and resin composite layers with different light sources. Cavities measuring 8x10 mm were prepared on the buccal surface of bovine incisors, leaving a remaining dentin thickness of 1 mm. Specimens were placed in a 37±1 °C water bath to standardize the temperature. The temperature in the pulp chamber was measured every 10 s during 40 s of light activation of the adhesive system (SBMP-3M/ESPE) and in the three consecutive 1-mm-thick layers of resin composite (Z250-3M/ESPE). Three light source devices were evaluated: Elipar 2500 (QTH), LD Max (LED low irradiance) and VALO (LED high irradiance). The results were submitted to one-way ANOVA with repeated measures and Tukey's test, both with p<0.001. The exothermic reaction warming was observed in the Z250 increments, but not in the SBMP. The high irradiance LED showed a higher temperature average (42.7±1.56 °C), followed by the quartz-tungsten-halogen light (40.6±0.67 °C) and the lower irradiance LED (37.8±0.12 °C). Higher temperature increases were observed with the adhesive and the first resin composite increment light-activation, regardless of the employed light source. From the second increment of Z250, the restorative material acted as a dispersive structure of heat, reducing temperature increases. Regardless the light source and restorative step, the temperature increased with the irradiation time. It may be concluded that the light source, irradiation time and resin composite thickness interfered in the temperature variation inside the pulp chamber.

Resumo O objetivo do presente estudo in vitro foi avaliar a variação de temperatura dentro da câmara pulpar durante a fotoativação de um sistema adesivo e de camadas de resina composta com diferentes fontes de luz. Cavidades com dimensões de 8x10 mm foram preparadas na superfície vestibular de incisivos bovinos deixando uma espessura de dentina remanescente de 1 mm. Os espécimes foram inseridos em uma cuba térmica com água à temperatura de 37±1 °C. A temperatura no interior da câmara foi medida a cada 10 s durante 40 s de ativação de luz do sistema adesivo (SBMP; 3M/ESPE) e três camadas de 1 mm de espessura consecutivas de resina composta (Z250; 3M/ESPE ). Três fonte de luz foram avaliadas: Elipar 2500 (QTH), LD Max (LED de baixa densidade de potência), VALO (LED alta densidade de potência). Os resultados foram submetidos a ANOVA de medidas repetidas a um critério e teste de Tukey (ambos com p<0,01). O aquecimento da reação exotérmica foi observado nos incrementos de resina composta, mas não no sistema adesivo. O LED de alta densidade de potência mostrou uma média de temperatura mais elevada (42,7±1,56 °C) seguido pela luz halogéna (40,6±0,67 °C) e o LED de menor densidade de potência (37,8±0,12 °C). Maiores aumentos de temperatura foram observados na fotoativação do sistema adesivo e do primeiro incremento de resina composta, independente da fonte de luz utilizada. A partir do segundo incremento de resina composta, o material restaurador agiu como estrutura dispersiva de calor, reduzindo o aumento de temperatura. Independente da fonte de luz e da etapa restauradora, a temperatura aumentou com o tempo de irradiação. Pode-se concluir que a fonte de luz, o tempo de irradiação, a espessura resina composta interferiram na variação de temperatura no interior da câmara pulpar.

Effect of Two Antioxidants Agents on Microtensile Bond Strength to Bleached Enamel

Abstract This in vitro study evaluated the effect of sodium bicarbonate and sodium ascorbate on the microtensile bond strength of an etch-and-rinse system to bleached bovine enamel. Sixty bovine enamel blocks (4x4 mm) were flattened and randomly allocated into 5 groups: G1 (negative control): without treatment; G2 (positive control): bleached with 35% hydrogen peroxide (HP); G3: bleached and stored for 7 days in artificial saliva before restorative procedures; G4: bleached and treated with 10% sodium bicarbonate solution for 5 min; G5: bleached and treated with 10% sodium ascorbate hydrogel for 15 min. HP gel was applied twice (20 min each, except in G1) and the adhesive restorations were performed. After 24 h, the specimens were sectioned into sticks and submitted to microtensile bond strength testing with a crosshead speed of 0.5 mm/min (n=12). As a complementary visual observation, the enamel surfaces of the G1 and G2 specimens were evaluated with scanning electron microscopy. Data were analyzed by one-way ANOVA (p<0.05). The means (standard deviation) were: G1: 24.22±7.74; G2: 18.29±5.88; G3: 40.88±7.95; G4: 19.95±5.67 and G5: 24.43±6.43. Adhesive failures were predominant in all groups. The comparison between the treatments indicates that waiting 7 days after bleaching is still the most effective approach. When this waiting period is not possible, application of sodium ascorbate or sodium bicarbonate seems to be a good alternative. Therefore, the practicality of obtaining sodium bicarbonate in the bleaching kits and its higher stability enables its clinical use.

Resumo Este estudo in vitro avaliou o efeito do bicarbonato de sódio e do ascorbato de sódio na resistência de união de um sistema adesivo convencional unido ao esmalte bovino clareado. Sessenta blocos de esmalte bovino (4x4 mm) foram planificados e distribuídos aleatoriamente em 5 grupos: G1: (controle negativo); G2 (controle positivo): clareamento com peróxido de hidrogênio 35% (HP); G3: clareamento com HP seguido de armazenamento por 7 dias em saliva artificial antes do procedimento restaurador; G4: clareamento com HP seguido de tratamento com a solução de bicarbonato de sódio 10% por 5 min; G5: clareamento com HP seguido de tratamento com hidrogel de ascorbato de sódio 10% por 15 min. O HP foi aplicado duas vezes (20 min cada, com exceção do grupo G1) e então as restaurações adesivas foram realizadas. Após 24 h, os espécimes foram seccionados em palitos e submetidos ao teste de resistência de união a uma velocidade de 0,5 mm/min (n=12). As superfícies de esmalte de G1 e G2 foram avaliadas com microscopia eletrônica de varredura para fins de análise visual complementar. Os dados foram analisados por ANOVA a um critério (p<0,05). As medias (desvio-padrão) foram: G1: 24,22±7,74; G2: 18,29±5,88; G3: 40,88±7,95; G4: 19,95±5,67 e G5: 24,43±6,43. Falhas adesivas foram predominantes em todos os grupos. A comparação entre os diferentes tratamentos indica que esperar 7 dias após o clareamento é ainda a abordagem mais eficaz. Nos casos em que este período de espera não é possível, a aplicação do ascorbato de sódio e do bicarbonate de sódio parecem ser boas alternativas. Entretanto, a praticidade na obtenção da solução de bicarbonato de sódio nos kits de clareamento e sua maior estabilidade favorecem o seu uso clínico.

Evaluation of temperature increase during in-office bleaching

ABSTRACT The use of light sources in the bleaching process reduces the time required and promotes satisfactory results. However, these light sources can cause an increase in the pulp temperature. Objective The purpose of the present study was to measure the increase in intrapulpal temperature induced by different light-activated bleaching procedures with and without the use of a bleaching gel. Material and Methods A human maxillary central incisor was sectioned 2 mm below the cementoenamel junction. A K-type thermocouple probe was introduced into the pulp chamber. A 35% hydrogen peroxide bleaching gel was applied to the vestibular tooth surface. The light units used were a conventional halogen, a hybrid light (only LED and LED/Laser), a high intensity LED, and a green LED light. Temperature increase values were compared by two-way ANOVA and Tukey´s tests (p<0.05). Results There were statistically significant differences in temperature increases between the different light sources used and between the same light sources with and without the use of a bleaching gel. The presence of a bleaching gel generated an increase in intra-pulpal temperature in groups activated with halogen light, hybrid light, and high intensity LED. Compared to the other light sources, the conventional halogen lamp applied over the bleaching gel induced a significant increase in temperature (3.83±0.41°C). The green LED unit with and without gel application did not produce any significant intrapulpal temperature variations. Conclusion In the present study, the conventional halogen lamp caused the highest increase in intrapulpal temperature, and the green LED caused the least. There was an increase in temperature with all lights tested and the maximum temperature remained below the critical level (5.5°C). The addition of a bleaching gel led to a higher increase in intrapulpal temperatures.

A simplified restorative technique of fractured maxillary anterior teeth

Introduction: Fractures of the anterior teeth consists of a clinical condition that generates not only aesthetic and psychological problems, but may also cause dental pain. Thus, the affected teeth should be treated as urgencies in dental offices and their resolution whenever possible should be in a single session. Direct resin composite restorations should wherever possible be preferred due to the speed and possibility of obtaining good results. Objective: The objective of this case report is to describe the clinical sequence for restoration of a maxillary central incisor that presented a crown fracture using an immediate insert technique for resin composite (a "free hand" technique) with a modification to obtain dentin layer. Case report: A patient sought treatment after she fractured tooth #21. The restoration was performed with resin composite using the immediate technique. To facilitate the layering technique, the immediate insertion technique was changed for making the dentin lobes with the aid of a Teflon tape and the support with the index finger. Conclusion: The restoration of fractured anterior teeth can be performed quickly with the use of resin composites of different opacities and the use of the technique of immediate insertion proposed in this case report.

Influence of pH, bleaching agents, and acid etching on surface wear of bovine enamel

ABSTRACT Development of new materials for tooth bleaching justifies the need for studies to evaluate the changes in the enamel surface caused by different bleaching protocols. Objective The aim of this study was to evaluate the bovine dental enamel wear in function of different bleaching gel protocols, acid etching and pH variation. Material and Methods Sixty fragments of bovine teeth were cut, obtaining a control and test areas. In the test area, one half received etching followed by a bleaching gel application, and the other half, only the bleaching gel. The fragments were randomly divided into six groups (n=10), each one received one bleaching session with five hydrogen peroxide gel applications of 8 min, activated with hybrid light, diode laser/blue LED (HL) or diode laser/violet LED (VHL) (experimental): Control (C); 35% Total Blanc Office (TBO35HL); 35% Lase Peroxide Sensy (LPS35HL); 25% Lase Peroxide Sensy II (LPS25HL); 15% Lase Peroxide Lite (LPL15HL); and 10% hydrogen peroxide (experimental) (EXP10VHL). pH values were determined by a pHmeter at the initial and final time periods. Specimens were stored, subjected to simulated brushing cycles, and the superficial wear was determined (μm). ANOVA and Tukey´s tests were applied (α=0.05). Results The pH showed a slight decrease, except for Group LPL15HL. Group LPS25HL showed the highest degree of wear, with and without etching. Conclusion There was a decrease from the initial to the final pH. Different bleaching gels were able to increase the surface wear values after simulated brushing. Acid etching before bleaching increased surface wear values in all groups.

Whitening gel and light source influence on pulp chamber temperature

Introduction: The chemical injury caused to the pulp by the penetration of the whitening gel is already known, but another possible cause may be the heat generated by the irradiation of the whitening gel with light sources to accelerate the whitening reaction. Objective: To evaluate in vitro the temperature increasing in the pulp chamber during in-office bleaching with different gel concentrations and light sources. Material and methods: A maxillary human central incisor was used in the 6 groups evaluated. The specimen was sectioned 3 mm apical to the cementoenamel junction. The root canal and pulp chamber were cleaned and widened with a diamond bur to receive the sensor of a thermocouple thermometer. The following hydrogen peroxide gel concentrations were evaluated: 35%, 25%, 15%, and 10%; and the following light sources were applied: blue hybrid LED/laser and violet hybrid LED/laser. The specimen bleaching was repeated 6 times per group. As a control, the temperature was measured with the application of light, without applying any gel. Results were evaluated with one-way ANOVA and Tukey's test (α = 5%). Results: Significant differences between groups were observed (p < 0.05). The blue LED without the gel induced the smallest heat (37.5 ± 0.2) and the blue LED with 15% gel caused the highest heat (38.2 ± 0.3). The combination of violet LED with the 10% gel caused no significant increase in temperature compared to the control in which light was used without gel (p> 0.05). Conclusion: No increase in pulp chamber temperature was higher than 2°C.

Curing depth of a silorane-based resin composite

Introduction: The silorane-based resin appears aiming to minimize the effects of polymerization shrinkage, but other properties must be studied. Objective: To evaluate the polymerization depth of two composites with different organic matrix. Material and methods: 80 cylindrical specimens were prepared using a metallic matrix, with three layers (top, middle and bottom), 1 mm high and 5 mm in diameter. The specimens were divided into eight groups (n = 10) according to the composite resins: Filtek P90 (3M/ESPE); Filtek Z250 (3M/ESPE), light-cured with a LED device with different irradiance and times (600mW/cm2 x 40s, 1000mW/cm2 x 40s, 1000mW/cm2 x 20s; 1400mW/cm2 x 20s). The irradiance was controlled by placing plastic rings coupled to the device's tip. Immediately after polymerization, the specimens' layers were separated and five Knoop microhardness readings (initial hardness) were performed on each one of the four layers (0, 1, 2, and 3 mm). After 7 day storage in water at 37ºC, new readings were performed (final microhardness). The data were analyzed by four-way ANOVA (resin, energy density, depth and time) and Tukey test (α = 0.05). Results: The microhardness decreased with the depth increasing both in the initial and 7 day readings. The hardness increased with the highest power densities. The resin P90 had lower hardness values. Conclusion: The silorane-based resin showed Knoop microhardness values significant smaller than those of methacrylate-based resin in almost all evaluated parameters. However, both presented similar behaviors in relation to the curing depth.

Indications and restorative techniques for glass ionomer cement

Introduction:Due to its chemical, mechanical and biological properties, the glass ionomer cements (GIC) consist in one of the most versatile direct restorative materials, with many potential clinical indications, especially in the context of minimally invasive dentistry. Nevertheless, they have some limitations and require the knowledge of their characteristics and procedures of application in order to achieve their maximum potential.Objective: To demonstrate through literature review the main characteristics, indications, limitations and future perspectives for the use of GIC. Literature review: The database, such as Pubmed and Lilacs were used. Additionally, books were also evaluated and included. Conclusion: The GIC is in constant evolution and is one of the materials that are best suited in the context of preventive and conservative dentistry. It has satisfactory properties and versatility. On the other hand, presents inferior properties when compared to other direct restorative materials, requiring caution during its handling.

Avaliação da temperatura dental in vitro em procedimentos de clareamento dental de consultório / Evaluation of the dental temperature in vitro in tooth whitening procedures at the dental office

Este trabalho teve por objetivo avaliar a variação de temperatura na face vestibular e intra câmara pulpar gerada por diferentes protocolos de clareamento em consultório. Um canino superior humano foi seccionado abaixo da junção amelocementária e teve o interior de sua câmara pulpar ampliado para receber uma pasta condutora térmica e o sensor do termômetro digital termopar tipo K. A aferição da temperatura na face vestibular foi realizada com termômetro digital infravermelho com Mira Laser. Os protocolos de clareamento no dente selecionado foram distribuídos em doze grupos experimentais, variando-se a luz de ativação: luz híbrida LED e laser diodo (UltraBlue© IV–DMC), luz halógena (Spectrum Curing Light©, Dentsply Caulk) e ultravioleta (Zoom! Lamp© – Discus Dental), e os tratamentos: sem gel clareador, Lase Peroxide© (DMC), Whiteness HP Maxx© (FGM) e Whiteness HP© (FGM). Os resultados foram submetidos … análise de variância a 2 critérios (ANOVA) e teste de tukey (p≤0,05). As maiores elevações de temperatura (5øC) no interior da câmara pulpar foram observadas nos grupos ativados com a lâmpada ultravioleta sem a utilização de gel e comWhiteness HP Maxx. A luz híbrida apresentou menor aumento de temperatura (de 1,7 a 2øC). Em relação à temperatura externa, a Zoom! Lamp também induziu o maior aumento, estatisticamente significante em relação aos demais. Tanto o gel clareador quanto a ativação por luz foram relevantes para o aumento de temperatura no interior da câmara pulpar. Na face vestibular o aumento de temperatura deu-se pela ativação por luz, independente do gel utilizado.

This study aimed to evaluate the temperature variation in the vestibular surface of teeth and inside their pulp chamber generated by different protocols in office whitening. A human upper canine was sectioned below the enamel-cement junction and had the interior of its chamber enlarged to receive a thermally conductive paste and the sensor of type K digital thermometer. The temperature measurement was performed on the vestibular surface with infrared digital thermometer with laser-sights. The protocols in tooth whitening selected were distributed in twelve experimental groups, varying the light activation: light hybrid LED and laser diode (UltraBlue IV© - DMC), halogen light (Spectrum Curing Light©, Dentsply Caulk) and ultraviolet (Zoom! Lamp© - Discus Dental), and treatments: no bleaching gel, Lase Peroxide© (DMC), Whiteness HP Maxx© (FGM), and Whiteness HP© (FGM). Results were subjected to variance analysis 2 way (ANOVA) and Tukey test (p≤0.05). The highest elevations of temperature (5øC) inside the pulp chamber were observed in the groups activated with ultraviolet light without the use of gel and Whiteness HP Maxx©. The light hybrid showed a smaller increase in temperature (from 1.7 to 2øC). On the facial surface, the Zoom! Lamp also induced the largest increase statistically significant in relation to others. Both the bleaching gel and light activation were relevant to the temperature increase inside the pulp chamber. In vestibular surface temperature increase occurred by light activation, regardless the used gel.

Liberação de flúor e potencial anticariogêncico de um cimento de ionômero de vidro modificado por resina em diferentes proporções pó/líquido, comparativamente a selantes / Fluoride release and the anticariogenic potential of a resin-modified glass ionomer cement with powder/liquid ratios with the sealants

A proposta deste estudo in vitro foi avaliar a capacidade de liberação de flúor e potencial anticariogênico do cimento de ionômero de vidro modificado por resina (CIVMR) Vitremer em 3 diferentes proporções pó/líquido (VT 1:1, VT ½:1 e VT »:1), comparativamente a dois selantes de fóssulas e fissuras (VS - Vitro-Seal Alpha e FS - FluroShield). Para a avaliação da liberação de flúor foram confeccionados 16 corpos de prova padronizados para cada grupo experimental. Oito espécimes por grupo foram submetidos a um modelo de ciclagem de pH e os demais imersos em água destilada deionizada. A concentração de flúor ( gF/cm2) nas soluções foi quantificada por um período de quinze dias. Para avaliação do potencial anticariogênico foram utilizados 12 blocos de esmalte humano 3x3 mm por grupo experimental, nos centros dos quais foram realizados preparos cavitários (Ï 1mm) e preenchimento com os diferentes materiais. Todos os espécimes foram submetidos à ciclagem de pH por um período de 7 dias. A avaliação do potencial anticariogênico foi realizada através da microdureza superficial e em secção longitudinal do esmalte a partir de distâncias padronizadas em relação ao material. Os resultados de liberação total de flúor durante os 15 dias, nas soluções de des/re e água foram, respectivamente: VS - 0,62 ±1,00; 0,35 ±0,80; FS - 3,26 ±3,80; 2,04 ±3,50; VT 1:1 - 10,41 ±11,20; 7,55 ±7,90; VT ½:1 - 29,16 ±31,00; 16,46 ±17,40 e VT »:1 - 34,00 ±34,50; 26,18 ±28,50. Os valores de por cento de perda mineral na superfície do esmalte à 50 m do material foram: VS - 94,4 +2,5; FS - 88,1 +4,9; VT 1:1 - 35,3 +9,6; VT ½:1 - 29,4 +15,0 e VT »:1 - 8,7 +4,2. A análise dos resultados demonstrou maior liberação de flúor nas soluções de des/re do que em água destilada deionizada...

Liberação de flúor do Vitremer em diferentes proporções pó/líquido, em compação com dois selantes de fóssulas e fissuras / Fluoride release of Vitremer in different powder/liquid ratio compared to two pit and fissure sealants

A proposta deste estudo in vitro foi avaliar a liberação de flúor do cimento de ionômero de vidro Vitremer/3M em três diferentes proporções pó/líquido (1:1, ½:1 e »:1), em comparação com dois selantes: FluroShield/Dentsply e Vitro-Seal Alpha/DFL. Oito espécimes foram submetidos a um modelo de ciclagem de pH, sendo imersos alternadamente em soluções de desmineralização (6h) e remineralização (18h) e outros oito mantidos em água deionizada a 37oC sob agitação, trocada diariamente, por 15 dias. A concentração de F liberada nos períodos de 24 horas, 7 e 15 dias foi analisada através do eletrodo íon específico (Orion 9609), após tamponamento com TISAB II. Os resultados, em µgF/cm2 demonstraram que o Vitremer nas proporções ½:1 e »:1, tanto em H2O como em des-/re-, apresentou liberação de F significativamente maior em relação aos demais grupos, conforme mostrado pela ANOVA e pelo teste de Tukey (p<0,05), não tendo havido diferença estatística significativa entre o Vitremer ½:1 e »:1 nas soluções de des-/re-. Assim, a alteração na consistência do Vitremer, tornando-o mais fluido, parece ser uma alternativa favorável sob o aspecto de liberação de F.