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

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.

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.

Remineralizing potential of a fluoride varnish modified by bioactive nanoparticles / Potencial remineralizante de um verniz fluoretado modificado por nanopartículas bioativas

Objective: Evaluate a fluoride varnish modified by nanostructures with the bioactive qualities of silica (SiO2) and niobium pentoxide (Nb2O5), testing its remineralizing potential by surface hardness (SH) and energy-dispersive X-ray spectroscopy (EDX). Material and Methods: Bovine enamel specimens (6×4×2mm) were prepared and submitted to a demineralizing/remineralizing process to produce a subsurface caries-like lesion, evaluated by transversal microradiography image (TMR) and subsequently distributed randomly into three groups: fluoride varnish (VZ); fluoride varnish + silica gelatin (VZ-SiO2) and fluoride varnish + niobium nanoparticles (VZ-Nb2O5). The specimens were subjected to a pH-cycling demineralizing/remineralizing process for 7 days at 37ºC. The %SH loss and %SH recovery (after the pH-cycling regimen) were calculated (n=10/group). The Ca/P weight ratio before and after the pH-cycling regimen was evaluated through SEM/EDX. A two-way ANOVA followed by Tukey's test (p<0.05) was performed for hardness and EDX. Results: TMR image showed the formation of an artificial subsurface lesion, and a significant SH increase was observed in the VZ-Nb2O5 group (p<0.05). Regarding the %SHL and %SHR, the VZ-Nb2O5 and VZ-SiO2 were significantly different compared to the VZ group (p<0.001), but VZ-Nb2O5 presented higher values. The Ca/P ratio showed that blocks treated with VZ-SiO2 and VZ-Nb2O5 showed greater ion deposition, particularly in the presence of Nb. Conclusion: The bioactivity of niobium facilitated greater interaction between the enamel and the varnish, leading to a slow release of nanoparticles and a longer-lasting remineralizing effect (AU)

Objetivo: Avaliar um verniz fluoretado modificado por nanoestruturas com a bioatividade da sílica (SiO2) e pentóxido de nióbio (Nb2O5), testando seu potencial remineralizador pela dureza de superfície (SH) e espectroscopia de energia dispersiva de raios-X (EDX). Material e Métodos: Espécimes de esmalte bovino (6×4×2mm) foram preparados e submetidos à desmineralização/remineralização para produzir uma lesão subsuperficial semelhante a cárie, avaliada por imagem de microrradiografia transversal (TMR) sendo distribuída em três grupos: verniz fluoretado (VZ); verniz fluoretado+gelatina de sílica (VZ-SiO2) e verniz fluoretado+nanopartículas de nióbio (VZ-Nb2O5). As amostras foram submetidas à desmineralização/remineralização por ciclagem de pH durante 7 dias a 37°C. A porcentagem de perda e recuperação de SH foram calculadas (n=10/grupo). A relação em peso Ca/P antes e depois da ciclagem foi avaliada através de MEV/EDX. ANOVA a dois critérios seguida do teste de Tukey (p<0,05) foi realizada para dureza e EDX. Resultados: A TMR mostrou a formação de uma lesão subsuperficial e um aumento significativo de SH foi observado no grupo VZ-Nb2O5 (p<0,05). Em relação ao %SHL e %SHR, o VZ-Nb2O5 e o VZ-SiO2 foram significativamente diferentes em relação ao grupo VZ (p<0,001), mas o VZ-Nb2O5 apresentou valores maiores. A relação Ca/P mostrou que os blocos tratados com VZ-SiO2 e VZ-Nb2O5 apresentaram maior deposição de íons, principalmente na presença de Nb. Conclusão: A bioatividade do nióbio facilitou maior interação entre o esmalte e o verniz, levando a uma liberação lenta de nanopartículas e a um efeito remineralizante mais duradouro (AU)

Effect of nanofibers as reinforcement on resin-based dental materials: A systematic review of in vitro studies.

This systematic review provides an update on the effect of nanofibers as reinforcement on resin-based dental materials. A bibliographic search was conducted in MEDLINEPubMed, Embase, Web of Science, Scopus, BVS (LILACS, BBO e IBECS), Cochrane, LIVIVO, and gray literature (BDTD) to identify relevant articles up to May 2021. In vitro studies that evaluated and compared the mechanical properties of nanofibers resin-based composite materials, were eligible. No publication year or language restriction was applied, and methodological quality was assessed using two methods. In a total of 6100 potentially eligible studies, 81 were selected for full-text analysis and 35 were included for qualitative analysis. Of the 35 included studies, a total of 29 studies evaluated the flexural strength (FS) of the materials. These groups were distinguished according to the resin-based materials tested and nanofiber types. Most of the studies evaluated materials composed of glass fibers and demonstrated higher values of FS when compared to resin-based materials without nanofibers. The incorporation of nanofibers into resin-based dental materials improved the mechanical properties compared to resin-based materials without nanofibers, suggesting better performance of these materials in high-stressbearing application areas. Further clinical studies are required to confirm the efficacy of resin-based materials with nanofibers.

The stamp technique for direct restoration in a ICDAS 4 carious lesion: A 4-year follow-up.

OBJECTIVE: This case report described the use of a stamping technique associated with a bulk fill composite to restore an ICDAS 4 carious lesion on a posterior tooth. The 4-year follow-up is also presented. CLINICAL CONSIDERATIONS: A 32-year-old patient presented a carious lesion on tooth 36 with an underlying dark shadow at the dentin seen from the noncavitated enamel occlusal surface, which was compatible with an ICDAS 4 carious lesion. The lesion was radiographically detected and the caries disease was treated with dietary and hygiene habits orientations. Before accessing the lesion and selectively removing the carious tissue, an occlusal stamp was made by applying a flowable resin composite to copy the anatomy of the noncavitated enamel surface. The cavity was restored using a bulk fill resin composite (Opus Bulk Fill, FGM) with 4-mm-thick increments. Before curing the last increment, a Teflon band was adapted at the uncured bulk fill composite surface and the occlusal stamp made with the flowable composite was pressed against it to reproduce the natural characteristics and initial occlusal anatomy. The top surface was light-activated for 40 s. After 4 years, small wear could be seen in the restoration, but still within clinically acceptable levels. CONCLUSION: The occlusal stamp technique allows reproduction of the natural anatomy of teeth affected by ICDAS 4 carious lesions with good clinical longevity over 4 years. CLINICAL SIGNIFICANCE: This case report presents the use of the stamp technique to restore a tooth affected by an ICDAS 4 lesion, in which a carious process reached the dentin and the enamel anatomy was still preserved. The bulk fill resin composite associated with the occlusal stamp was chosen to quickly restore the cavity with clinical predictability. Bulk fill composites allow the insertion of up to 4-mm-thick increments and offer lower shrinkage stress, good clinical longevity and a less time-consuming procedure in cases of posterior teeth, especially if associated with the stamp technique.

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)

Cephalometric and occlusal changes of Class III malocclusion treated with or without extractions.

OBJECTIVE: The aim of this retrospective study was to evaluate the cephalometric and occlusal changes of orthodontically treated Class III malocclusion patients. METHODS: The experimental groups comprised 37 Class III patients treated: G1) without (n=19) and G2) with extractions (n=18) . The control group (G3), matched by age and sex with the experimental groups, consisted of 18 subjects with untreated Class III malocclusion. Cephalometric (radiographs) and occlusal (study models) changes were assessed between the beginning (T1) and the end (T2) of treatment. Intergroup comparisons were performed with one-way ANOVA followed by Kruskal-Wallis tests (p< 0.05). Occlusal changes were evaluated by the peer assessment rating (PAR) index (ANOVA and Kruskal-Wallis tests), and the treatment outcomes were evaluated by the Objective Grading System (OGS) (t-tests). RESULTS: The experimental groups showed a restrictive effect on mandibular anterior displacement and a discrete improvement in the maxillomandibular relationship. Extraction treatment resulted in a greater retrusive movement of the incisors and significant improvements in the overjet and molar relationship in both groups. The PAR indexes were significantly reduced with treatment, and the OGS scores were 25.6 (G1) and 28.6 (G2), with no significant intergroup difference. CONCLUSIONS: Orthodontic treatment of Class III malocclusion patients with fixed appliances improved the sagittal relationships, with greater incisor retrusion in the extraction group. Both the extraction and non-extraction treatments significantly decreased the initial malocclusion severity, with adequate and similar occlusal outcomes of treatment.

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)

Physical and surface properties of a 3D-printed composite resin for a digital workflow.

STATEMENT OF PROBLEM: Information related to the optical and surface properties, including health compatibility, surface roughness, and esthetics, of 3D-printed dental materials is scarce. PURPOSE: The purpose of this in vitro study was to compare the physical and surface properties of a 3D-printed resin with those of materials used for interim restorations. MATERIAL AND METHODS: A 3D-printed resin (PR) (NextDent C&B MFH; 3D Systems), an autopolymerizing interim material (BA) (Protemp 4; 3M ESPE), and a composite resin (Z350) (Filtek Z350XT; 3M ESPE) were tested for degree of color change (ΔE) (n=7) at different timepoints-24 hours after polishing/baseline (P0), 8 days after polishing (P1), and after artificial aging in water at 60 °C for 24 hours (P2)-by using a CIELab-based colorimeter; flexural strength (σ) (n=10) with a 3-point bend test; Knoop hardness (H) (n=8); and surface roughness (Ra) (n=7) with a profilometer. All specimens were polished 24 hours after polymerization, except for the additional group for surface roughness (BA) without polishing (BANP). A statistical analysis was performed by using 2-way repeated-measures ANOVA followed by the Fischer test for ΔE and 1-way ANOVA followed by the Fisher test for microhardness and surface roughness (α=.05). RESULTS: The Z350 showed the highest values for σ and H, followed by PR. BA showed the lowest results for both tests (P<.05). Considering roughness, the Z350 showed similar values to those of BA but lower than PR; PR showed similar roughness when compared with BA. PR showed the highest color variation among the groups at all timepoints, followed by BA. The Z350 was the most color stable material at all timepoints. CONCLUSIONS: The 3D-printed composite resin had adequate mechanical and surface properties for an interim restorative material. It has the potential to be a low-cost workflow in dentistry, although its color stability could be a concern for long-term use.

Marginal and internal adaptation of lithium disilicate partial restorations: A systematic review and meta-analysis.

AIM: The aim of this meta analysis was to evaluate the influence of the processing method on the marginal and internal gaps of lithium disilicate inlays/onlays. SETTINGS AND DESIGN: A systematic literature review was conducted using the PubMed/Medline, Embase, Scopus, and Cochrane Library databases. This review was registered on the PROSPERO platform. MATERIALS AND METHODS: The studies were selected according to the marginal and internal gaps of two different fabrication methods for lithium disilicate (milled and pressed). STATISTICAL ANALYSIS USED: The meta analysis was performed based on the Mantel-Haenszel and inverse variance methods, using the random effects model and a 95% confidence interval. RESULTS: From all databases, 127 studies were identified. Four in vitro studies were included in the qualitative analysis and three in the meta analysis. Moreover, 197 restorations were evaluated (103 pressed and 94 milled). During the evaluation of only the internal gap, there was a statistically significant difference favoring the pressed technique (P = 0.002). There was no statistically significant difference in the analyses of the marginal gap (P = 0.530) and the total gap (P = 0.450). CONCLUSION: Both the techniques provided acceptable marginal and total gaps, although the pressed technique revealed a more favorable internal adaptation than the milled onlays/inlays.

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

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.

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.

Clinical performance of the composite resin veneers: the minimally invasive approach / Desempenho clínico de facetas de resina composta: uma abordagem minimamente invasiva / Desempeño clínico de las carillas de resina compuesta: un enfoque mínimamente invasivo

Minimally invasive approach lead composite resin veneers restorations as a conservative and alternative treatment option, with the aim to improve the aesthetics anterior dentition. Clinically, this treatment reducing the clinical time and has a lower cost than indirect technique. In addition, new resin composite was developed to support the clinician to make more natural restorations. The present case report aim to evaluated the clinical performance of direct composite veneer technique was restored with 100% supra-nano spherical filler composite. A 39-year-old female, searched for restorative treatment of anterior teeth, which were unaesthetically altered. In the clinical examination, it was observed color alterations in maxillary left and right incisors and canines due to use of medicines, and bruxism. The treatment plan included an in-office dental bleaching, removal of inadequate anterior restorations and confection of composite veneers restorations. The dental bleaching was performed with hydrogen peroxide 35% activated by LED/laser in two sessions. Those restorations were performed using supra-nano spherical resin-based composite, color A1 for dentin and enamel, with direct composite laminate veneer technique. After six-month follow-up, the restorations presented good clinical aspect, absence of biofilm accumulation and abrasive wear. Therefore, direct veneer restorations may be alternative treatment for anterior teeth esthetic problems, suggesting a promising performance of these new composites(AU)

A abordagem minimamente invasiva torna as facetas de resina composta conservadoras e opção de tratamento alternativo para melhorar a estética da dentição anterior. Clinicamente, esse tratamento reduz o tempo operatório e tem um custo menor que a técnica indireta. Além disso, uma nova resina composta foi desenvolvida para ajudar o clínico a fazer restaurações mais naturais. O presente relato de caso tem como objetivo avaliar o desempenho clínico da técnica direta de faceta de resina composta de preenchimento 100% supra-nano-esférico. Paciente de 39 anos, sexo feminino procurou o tratamento restaurador dos dentes anteriores, que foram alterados inesteticamente. No exame clínico foram observadas alterações de cor nos incisivos superiores, esquerdo e direito, e caninos devido ao uso de medicamentos e bruxismo. O plano de tratamento incluiu clareamento dentário em consultório, remoção de restaurações anteriores inadequadas e confecção de facetas de resina composta. O clareamento dental foi realizado com peróxido de hidrogênio a 35% ativado por LED / laser em duas sessões. Essas restaurações foram realizadas utilizando resina composta supra-nano-esférica, cor A1 para dentina e esmalte, com técnica direta de laminado composto. Após seis meses de acompanhamento as restaurações apresentaram bom aspecto clínico, ausência de acúmulo de biofilme e desgaste abrasivo. Portanto, facetas diretas de resina composta podem ser um tratamento alternativo para problemas estéticos de dentes anteriores, sugerindo um desempenho promissor desses novos compósitos(AU)

El abordaje mínimamente invasivo hace que las facetas de resina compuesta conservadoras y opción de tratamiento alternativo para mejorar la dentición anterior estética. Clínicamente, este tratamiento reduce el tiempo clínico y tiene un costo menor que la técnica indirecta. Además, un nuevo compuesto de resina fue desarrollado para ayudar al clínico a hacer restauraciones más naturales. El presente relato de caso tiene como objetivo evaluar el desempeño clínico de la técnica directa de faceta de resina compuesta de relleno 100% supra-nano-esférico. Paciente de 39 años, sexo femenino buscó el tratamiento restaurador de los dientes anteriores, que fueron alterados intemporal. En el examen clínico se observaron alteraciones de color en los incisivos superiores, izquierdo y derecho, y caninos debido al uso de medicamentos y bruxismo. El plan de tratamiento incluyó blanqueamiento dental en consultorio, remoción de restauraciones anteriores inadecuadas y confección de facetas de resina compuesta. El blanqueamiento dental fue realizado con peróxido de hidrógeno al 35% activado por LED / láser en dos sesiones. Estas restauraciones se realizaron utilizando resina compuesta supra-nano esférica, color A1 para dentina y esmalte, con técnica directa de laminado compuesto. Después de seis meses de seguimiento las restauraciones presentaron buen aspecto clínico, ausencia de acumulación de placa dental y desgaste abrasivo. Por lo tanto, las facetas directas de resina compuesta pueden ser un tratamiento alternativo para problemas estéticos de dientes anteriores, sugiriendo un desempeño prometedor de estos nuevos compuestos(AU)

The effects of hybrid light activation and enamel acid etching on the effectiveness, stability and sensitivity after a single session in-office bleaching: A 12-month clinical trial.

BACKGROUND: The use of hybrid-light (HL) during in-office teeth bleaching can provide faster and reliable results after a single bleaching session, especially if associated with previous acid etching. The present in vivo, interventional, split-mouth, triple-blinded and randomized study evaluated the efficiency of a HL, with and without prior enamel acid etching, assessing the gel application time, degree of color change, sensitivity and treatment stability up to 12 months. METHODS: Thirty-four patients were selected and randomly divided into four groups. The color was evaluated using a spectrophotometer with the CIELab color system, and a VAS questionnaire was used to evaluate the sensitivity. Both upper and lower hemiarches (GI and III) received enamel acid etching with 37% phosphoric acid for 15 s prior to the application of 35% hydrogen peroxide gel (HP). For GI and II, HP was applied on both dental arches for 3-4 consecutive applications and activated by HL (2 × 3' activations with 1' interval); and 3 × 15' (HP) for GIII and IV without HL. Patients returned in 24 h, 1 week, 1-, 6- and 12-months intervals. The clinical operator was different from the clinical measurements operator. RESULTS: After 3-way ANOVA, Tukey's, Wilcoxon and Mann-Whitney tests, all with p < 0.05, no statistical differences were observed between the groups regarding color change (ΔE) and sensitivity in all evaluations. The lowest gel application time was observed for GII (acid etch + HL), followed by GI (HL). CONCLUSIONS: The present study's results reveal the advantages of HL associated with acid etching prior to in office bleaching.

Influence of light activation of simplified adhesives on the shear bond strength of resin cements to a leucite-reinforced ceramic.

OBJECTIVE: This study aims to evaluate the influence of the light activation of simplified adhesives on the shear bond strength of resin cements to a glass-ceramic. Three factors were evaluated: (1) cement in two levels (light cured and dual cured); (2) adhesive in two levels (Single Bond 2 and Single Bond Universal), and (3) light activation in two levels (yes or no). MATERIALS AND METHODS: Thirty-two 1-mm thick slices of a leucite-reinforced glass-ceramic (IPS Empress CAD) were divided into eight groups according to adhesive (Single Bond 2 or Single Bond Universal), cement (AllCem Veneer or AllCem), and light activation of the adhesive before application of the cement (yes or no). Ceramic surfaces were etched for 60 s with 5% hydrofluoric acid, and adhesives were applied. Four cement cylinders were made over each ceramic slice (n = 16) and then submitted to shear bond strength tests. STATISTICAL ANALYSIS: Data were analyzed with three-way ANOVA and Tukey (α = 0.05). RESULTS: There were significant differences between adhesives (P < 0.0001) and no differences between cements (P = 0.0763) and light activation (P = 0.4385). No interaction effect occurred (P = 0.05). Single Bond 2 showed higher bond strength than Single Bond Universal. CONCLUSIONS: The light activation of the adhesive before the application of the resin cement did not influence the bond strength.

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)

Estratégias para o aumento da previsibilidade na abordagem multidisciplinar da Odontologia estética / Strategies to increase predictability in cosmetic dentistry multidisciplinary approach

O planejamento estético multidisciplinar traz conceitos de excelência na resolução de casos complexos e desafiadores em Odontologia. O presente relato de caso clínico aborda os princípios, indicações e técnica operatória para a resolução estética de dentes escurecidos, com restaurações extensas insatisfatórias e pigmentadas e arranjo periodontal desarmônico, através de uma abordagem interdisciplinar guiada. O planejamento estético digital foi delineado para orientação do enceramento diagnóstico e confecção de guia cirúrgico para a gengivoplastia. Os dentes anteriores foram clareados e considerando a condição dos mesmos após remoção das restaurações insatisfatórias foram propostas restaurações cerâmicas indiretas, uma faceta unitária no elemento 11 e um laminado cerâmico no elemento 12. Diante do resultado alcançado, revela-se importante a correta indicação e a utilização de estratégias clínicas que guiem os procedimentos operatórios no objetivo de prover conservadorismo e biomimetismo (AU).

The multidisciplinary aesthetic planning brings excellence concepts in the resolution of complex and challenging cases in dentistry. This case report addresses the principles, indications and the surgical technique for aesthetic resolution of darkened teeth, with extensive unsatisfactory and pigmented restorations, and disharmonious periodontal arrangement through a guided interdisciplinary approach. Digital aesthetic planning was designed to guide the wax-up diagnosis and to make surgical guide for gingivoplasty. Anterior teeth whitening was performed and considering their condition after removal of the unsatisfactory restorations, indirect ceramic restorations were proposed, a unitary ceramic veneer (11) and a laminate veneer (12). Considering the result achieved, it is important to consider the correct indication and the use of clinical strategies that guide the surgical procedures in order to provide conservatism and biomimicry (AU).

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

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.

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

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.