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. highviscosity high viscosity bulkfill bulk fill 05 0 5 0.5 feature weighed minute control, control , control) BF05 BF0 BF0. fillers) U Shofu control. . 1 specimensgroups 8 ( mm FS (FS Instron (Instron 500N. 500N N (500N) KH (KH) DoC (DoC) DC (DC) E, E (E) ΔE (ΔE) Fouriertransformed Fourier transformed accessory Oneway One way Tukeys Tukey s p<0.05, p005 p p<0.05 (p<0.05) p<0.05. technology 0. (500N (KH (DoC (DC (E (ΔE p00 p<0.0 (p<0.05 p0 p<0. (p<0.0 p<0 (p<0. p< (p<0 (p< (p

Resumo Este estudo in vitro sintetizou nanofibras híbridas embebidas em óxido de grafeno (GO), incorporando-as à uma resina composta experimental de monômeros para avaliar suas propriedades físico-mecânicas. Nanofibras híbridas inorgânica-orgânicas foram produzidas com soluções precursoras de fibras poli (d, l-lactídeo, PLA) preenchidas com GO a 1% em peso e microscopia eletrônica de varredura (MEV) e espectroscopia de raio-X de energia dispersiva (EDS) caracterizaram a morfologia e composição química das fibras. Monômeros de resina composta foram desenvolvidos e um total de 5% de nanofibras foi incorporado aos materiais experimentais. Três grupos foram desenvolvidos: G1 (monômeros de resina controle), G2 (monômeros de resina/ nanofibras de PLA) e G3 (monômeros de resina/nanofibras híbridas inorgânico-orgânicas). Ângulo de contato (n=3), resistência à flexão (n=22), módulo de elasticidade (n=22) e dureza Knoop (n=6) foram avaliados. A média das três endentações foi obtida para cada amostra. A normalidade dos dados foi avaliada pelo QQ Plot com envelopes simulados e analisada pelo método de Welch (p<0,05). No geral, as imagens de MEV mostraram forma regular de nanofibras, mas não alinhadas. A análise composicional de EDS (n=6) revelou a presença de carbono e oxigênio (presentes na composição do GO) e Si resultante do processo de funcionalização. Os resultados do ângulo de contato (°) e dureza (Kg/mm2) para cada grupo foram os seguintes, respectivamente: G1 (59,65±2,90; 37,48±1,86a), G2 (67,99±3,93; 50,56±1,03b) e G3 (62,52±7,40; 67,83±1,01c). G3 apresentou os maiores valores de dureza Knoop (67,83 kg/mm2), e a resistência à flexão de todos os grupos foi prejudicada. A resina composta experimental composta por nanofibras híbridas com GO apresentou maiores valores de dureza e comportamento hidrofílico. GO, , (GO) incorporandoas incorporando físicomecânicas. físicomecânicas físico mecânicas. mecânicas físico-mecânicas inorgânicaorgânicas inorgânica orgânicas d, d (d llactídeo, llactídeo l lactídeo, lactídeo l-lactídeo PLA 1 (MEV raioX raio X (EDS 5 experimentais G controle, controle controle) resinananofibras inorgânicoorgânicas. inorgânicoorgânicas inorgânico . inorgânico-orgânicas) n=3, n3 n n=3 3 (n=3) n=22, n22 n=22 22 (n=22 n=6 n6 6 (n=6 avaliados amostra p<0,05. p005 p p<0,05 0 05 (p<0,05) geral alinhadas presentes funcionalização ° (° Kg/mm2 Kgmm2 Kgmm Kg mm2 mm (Kg/mm2 seguintes respectivamente 59,65±2,90 5965290 59 65 2 90 (59,65±2,90 37,48±1,86a, 3748186a 37,48±1,86a 37 48 86a 37,48±1,86a) 67,99±3,93 6799393 67 99 93 (67,99±3,93 50,56±1,03b 5056103b b 50 56 03b 62,52±7,40 6252740 62 52 7 40 (62,52±7,40 67,83±1,01c. 6783101c c 67,83±1,01c 83 01c 67,83±1,01c) 67,83 6783 (67,8 kg/mm2, kgmm2 kgmm kg/mm2 kg kg/mm2) prejudicada hidrofílico (GO inorgânico-orgânicas n= (n=3 n2 n=2 (n=2 (n= p00 p<0,0 (p<0,05 ( Kg/mm (Kg/mm 59,65±2,9 596529 9 (59,65±2,9 4 67,99±3,9 679939 (67,99±3,9 62,52±7,4 625274 (62,52±7,4 8 67,8 678 (67, kg/mm (n p0 p<0, (p<0,0 59,65±2, 59652 (59,65±2, 67,99±3, 67993 (67,99±3, 62,52±7, 62527 (62,52±7, 67, (67 p<0 (p<0, 59,65±2 5965 (59,65±2 67,99±3 6799 (67,99±3 62,52±7 6252 (62,52±7 (6 p< (p<0 59,65± 596 (59,65± 67,99± 679 (67,99± 62,52± 625 (62,52± (p< 59,65 (59,65 67,99 (67,99 62,52 (62,52 (p 59,6 (59,6 67,9 (67,9 62,5 (62,5 59, (59, 62, (62, (59 (62 (5

Abstract This in vitro study synthesized hybrid nanofibers embedded in graphene oxide (GO) and incorporated them into experimental resin composite monomers to evaluate their physical-mechanical properties. Inorganic-organic hybrid nanofibers were produced with precursor solutions of 1% wt. GO-filled Poly (d,l-lactide, PLA) fibers and scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) characterized the morphology and chemical composition of the spun fibers. Resin composite monomers were developed and a total of 5% nanofibers were incorporated into the experimental materials. Three groups were developed: G1 (control resin monomers), G2 (resin monomers/PLA nanofibers), and G3 (resin monomers/inorganic-organic hybrid nanofibers). Contact angle (n=3), flexural strength (n=22), elastic modulus (n=22), and Knoop hardness (n=6) were evaluated. The mean of the three indentations was obtained for each sample. The normality of data was assessed by QQ Plot with simulated envelopes and analyzed by Welch's method (p<0.05). Overall, SEM images showed the regular shape of nanofibers but were non-aligned. Compositional analysis from EDS (n=6) revealed the presence of carbon and oxygen (present in GO composition) and Si from the functionalization process. The results of contact angle (°) and hardness (Kg/mm2) for each group were as follow, respectively: G1 (59.65±2.90; 37.48±1.86a), G2 (67.99±3.93; 50.56±1.03b) and G3 (62.52±7.40; 67.83±1.01c). The group G3 showed the highest Knoop hardness values (67.83 kg/mm2), and the flexural strength of all groups was adversely affected. The experimental resin composite composed of hybrid nanofibers with GO presented increased hardness values and hydrophilic behavior. (GO physicalmechanical physical mechanical properties Inorganicorganic Inorganic organic 1 wt GOfilled filled d,llactide, dllactide d,l lactide, d l lactide (d,l-lactide PLA (SEM energydispersive energy dispersive Xray X ray (EDS 5 materials G control monomers, , monomers) monomersPLA nanofibers, nanofibers) monomers/inorganicorganic monomersinorganicorganic monomers/inorganic inorganic nanofibers. . n=3, n3 n n=3 3 (n=3) n=22, n22 n=22 22 (n=22) n=6 n6 6 (n=6 evaluated sample Welchs Welch s p<0.05. p005 p p<0.05 0 05 (p<0.05) Overall nonaligned. nonaligned non aligned. aligned non-aligned present process ° (° Kg/mm2 Kgmm2 Kgmm Kg mm2 mm (Kg/mm2 follow respectively 59.65±2.90 5965290 59 65 2 90 (59.65±2.90 37.48±1.86a, 3748186a 37.48±1.86a 37 48 86a 37.48±1.86a) 67.99±3.93 6799393 67 99 93 (67.99±3.93 50.56±1.03b 5056103b b 50 56 03b 62.52±7.40 6252740 62 52 7 40 (62.52±7.40 67.83±1.01c. 6783101c c 67.83±1.01c 83 01c 67.83±1.01c) 67.83 6783 (67.8 kg/mm2, kgmm2 kgmm kg/mm2 kg kg/mm2) affected behavior llactide d,llactide dl inorganicorganic monomersinorganic n= (n=3 n2 n=2 (n=22 (n= p00 p<0.0 (p<0.05 ( Kg/mm (Kg/mm 59.65±2.9 596529 9 (59.65±2.9 4 67.99±3.9 679939 (67.99±3.9 62.52±7.4 625274 (62.52±7.4 8 67.8 678 (67. kg/mm (n=2 (n p0 p<0. (p<0.0 59.65±2. 59652 (59.65±2. 67.99±3. 67993 (67.99±3. 62.52±7. 62527 (62.52±7. 67. (67 p<0 (p<0. 59.65±2 5965 (59.65±2 67.99±3 6799 (67.99±3 62.52±7 6252 (62.52±7 (6 p< (p<0 59.65± 596 (59.65± 67.99± 679 (67.99± 62.52± 625 (62.52± (p< 59.65 (59.65 67.99 (67.99 62.52 (62.52 (p 59.6 (59.6 67.9 (67.9 62.5 (62.5 59. (59. 62. (62. (59 (62 (5

Resumo O presente estudo teve como objetivo avaliar as propriedades de polimerização de materiais bulk-fill (baixa e alta viscosidade) utilizando luz contínua de alta intensidade e fotoativação intermitente em relação ao estresse de contração de polimerização e grau de conversão (DC). As seguintes resinas compostas Bulk-fill e nanohíbridas convencionais foram avaliadas: Filtek Z350XT Flow (3M/ESPE), SureFil SDR Flow (Dentsply), Filtek Bulk Fill Flow (3M/ESPE), Filtek Z350XT (3M/ESPE) e Filtek Bulk Fill Posterior (3M/ESPE). Um dispositivo de LED (DB 685, Dabi Atlante) foi utilizado nos dois protocolos: fotoativação contínua e intermitente contínua (ciclos de liga e desliga) com exposição idêntica (14 J/cm2). A tensão de contração de polimerização (n=6) foi avaliada através da inserção de um incremento único de 12 mm3 entre duas placas de aço inoxidável (6×2 mm) adaptadas a uma Máquina de Ensaio Universal (UTM), em tempos diferentes. As medições foram registradas após a fotoativação. O grau de conversão foi avaliado por FTIR-ATR (n=5). Os dados foram analisados pelos testes ANOVA a três fatores e teste de Tukey (α=0,05). A resina Bulk Fill Posterior apresentou maiores valores de tensão de contração quando fotoativadas com a técnica intermitente (p<0,05). A fotoativação intermitente aumentou o grau de conversão nas resinas bulk-fill de baixa viscosidade (p<0,05). Portanto, o uso de fotoativação modulada (intermitente) deve ser indicado com cautela, uma vez que seu uso pode influenciar a tensão de contração e o grau de conversão dos compósitos, o que varia de acordo com as formulações da resina.

Abstract This study aimed to evaluate the polymerization properties of bulk-fill materials (low and high-viscosity) by using high-intensity continuous light and intermittent photo-activation in terms of polymerization shrinkage stress and degree of conversion (DC). The following Bulk-fill and Conventional nanofilled resin composites were evaluated: Filtek Z350XT Flow (3M/ESPE), SureFil SDR Flow (Dentsply), Filtek Bulk Fill Flow (3M/ESPE), Filtek Z350XT (3M/ESPE) and Filtek Bulk Fill Posterior (3M/ESPE). A LED device (DB 685, Dabi Atlante) was used for both protocols: continuous uniform and intermittent photo-activation (light-on and light-off cycles) with identical radiant exposure (14 J/cm2). The polymerization shrinkage stress (n=6) was evaluated by inserting a single increment of 12 mm3 between two stainless steel plates (6×2 mm) adapted to a Universal Testing Machine (UTM), at different times. Measurements were recorded after photo-activation. The degree of conversion was evaluated by Fourier transformed infrared spectroscope (FTIR) with an attenuated total reflectance (ATR) accessory (n=5). Data were analyzed by three-way ANOVA and Tukey’s HSD (α=0.05) tests. Bulk Fill Posterior presented higher shrinkage stress values when photo-activated with the intermittent technique (p<0.05). The intermittent photo-activation increased the degree of conversion for the low-viscosity bulk-fills (p<0.05). Therefore, the use of modulated photo-activation (intermittent) must be indicated with caution since its use can influence the shrinkage stress and degree of conversion of composites, which varies according to the resin formulations.

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.

Abstract This study evaluated the effect of adding the hydrophobic monomer 1,12 dodecanediol dimethacrylate (DDDMA) to experimental sealants with and without thermocycling on degree of conversion (DC), water sorption (WS), water solubility (WSB), color stability (ΔE), and micro-shear bond strength (μSBS). Five experimental and one commercially available sealant (Bisco - BIS) were tested. The experimental sealants were formulated by mixing different percentages of DDDMA monomers and urethane dimethacrylate (UDMA). The photoinitiator system was composed by camphorquinone (CQ) and tertiary amine 4-ethyl benzoate dimetilamiono (EDBA). Ethanol was used as a solvent. The experimental groups were named sequentially according to the monomeric content (DDDMA/UDMA): S40/40 (40/40), S50/30 (50/30), S60/20 (60/20), S70/10 (70/10) and S80/0 (80/0). Data were analyzed separately by one-way ANOVA, followed by Tukey’s test (p<0.05). The values of DC ranged from 94.59% (S40/40) to 54.02% (S80/10). BIS showed the highest WS value (p<0.05) and S40/40, S50/30, S60/20 and S80/0 showed the lowest WS values of all tested sealants. WSB values ranged from 7.88 µg/mm3 (BIS) to 13.27 µg/mm3 (S70/10). The highest ΔE value was 11.05±2.88 for BIS and the highest μSBS value was found for S60/20. No significant difference was observed in bond strength between sealants and bovine enamel after thermocycling. Adding DDDMA to the composition of surface sealants can improve its performance, once the monomer increased the degree of conversion and the color stability.

RESUMO As restaurações de resinas compostas têm aumentado consideravelmente em popularidade e previsibilidade, possibilitando a realização de um tratamento odontológico minimamente invasivo. No entanto, para se obter o sucesso das restaurações de resina composta é necessário ter conhecimento dos materiais adesivos e da técnica de utilização, caso contrário os insucessos podem aparecer rapidamente. Assim, o objetivo deste trabalho foi realizar uma revisão de literatura sobre o desempenho clínico de diferentes tipos de resinas compostas e de sistemas adesivos no que se refere à longevidade. Para essa avaliação foram verificadas algumas características das restaurações logo após elas serem finalizadas e depois de um determinado tempo. Características como sensibilidade pós-operatória, cor, integridade marginal, cárie secundária, textura, adaptação marginal, retenção, deslocamento, descoloração marginal, forma anatômica, tiveram seus desempenhos comparados. A influência dos vários sistemas adesivos na longevidade das restaurações foi também observada em função da sua fundamental importância na união entre o dente e o material restaurador. Concluiu-se que a maioria das restaurações se apresentou clinicamente aceitável, quando se usou resinas compostas híbridas, nanoparticuladas ou microhíbridas e sistema adesivo convencional.

ABSTRACT Composite resin restorations have increased considerably in popularity and predictability, enabling the realization of a minimally invasive dental treatment. However, to obtain the success of composite resin restorations, knowledge of adhesives and the use of the technique are required, otherwise failure may appear quickly. The objective of the present work was to conduct a literature review on the clinical performance of different types of composite resins and adhesive systems with regard to longevity. For this evaluation, some characteristics of the restorations were immediately verified after they were completed and after a determined time. Characteristics such as postoperative sensitivity, color, marginal integrity, secondary caries, texture, marginal adaptation, retention, displacement, marginal discoloration and anatomical shape had their performances compared. The influence of different adhesive systems on the longevity of the restorations was also observed as a function of its fundamental importance in the union between the tooth and the restorative material. It was concluded that most restorations performed clinically acceptable when hybrid, nanoparticle or microhybrid composite resins and conventional adhesive systems were used.