Over-the-counter products in tooth bleaching: A scoping review.

OBJECTIVE: To map and summarize the current scientific evidence concerning the active ingredients, effectiveness, and adverse effects of over-the-counter (OTC) bleaching products. DATA AND SOURCE: This study was conducted according to the PRISMA-ScR guidelines for scoping reviews and registered on the Open Science Framework platform. STUDY SELECTION: Database searches were conducted in PubMed/MEDLINE, Embase, and Scopus up to January 2024. All in vitro, in situ, and clinical studies evaluating the effectiveness and adverse effects of OTC bleaching products were included. A descriptive analysis of the included studies was performed. RESULTS: A total of 88 studies were included. Most of them were in vitro studies (n = 49), followed by randomized clinical trials (n = 28). The main OTC bleaching products identified were whitening or stain-removing toothpastes (n = 42), followed by whitening strips (n = 39). Most clinical studies indicate that whitening strips are effective in improving tooth color and providing whitening benefits. In contrast, the bleaching effectiveness of toothpastes, mouth rinses and whitening trays was mainly supported by in vitro studies. The main adverse effects associated with OTC bleaching agents were tooth sensitivity and gingival irritation. CONCLUSION: A wide variety of OTC bleaching products is available for consumer self-administered use. Clinical studies have mainly confirmed the bleaching effectiveness of whitening strips, while the validation for toothpastes, mouth rinses and whitening trays has mainly relied on in vitro studies. Nevertheless, the use of OTC bleaching products may result in adverse effects, including tooth sensitivity, gingival irritation, and enamel surface changes. CLINICAL SIGNIFICANCE: Some over-the-counter bleaching products may have whitening properties supported by clinical studies, particularly those containing hydrogen or carbamide peroxide. Nonetheless, clinicians must be aware of the potential risks associated with excessive self-administration of these products, which may result in adverse effects.

Scoping review: Effect of surface treatments on bond strength of resin composite repair.

OBJECTIVE: to evaluate the existing evidence on surface treatment techniques employed in resin composite repair and their effect on the repair short- and long-term bond strength. DATA AND SOURCE: This scoping review was performed under the PRISMA-ScR guidelines for scoping reviews and registered on the Open Science Framework platform. STUDY SELECTION: A systematic search was conducted in PubMed, Embase, and Scopus and grey literature up to September 2022 without language or date restriction. In vitro studies comparing mechanical surface and/or chemical treatments on repair bond strength of resin composite were included. Studies evaluating experimental adhesive systems or resin composites were excluded. Selection of studies and data extraction were performed. Data from selected studies was qualitatively analyzed. RESULTS: A total of 76 studies were included in the qualitative analysis. Among the mechanical treatments, alumina blasting was the most frequently used, followed by silica coating and diamond bur. As for chemical treatments, dentin bonding systems were the most frequently evaluated, followed by universal adhesive systems and silane/ceramic primer. The combination of mechanical and chemical pre-treatments increased the repair bond strength of resin composite in both short- and long-term simulated aging scenarios. The evidence obtained from the included studies was classified as moderate quality, mainly due to the medium risk of bias observed across most of the studies. CONCLUSION: The techniques used to treat the surface of resin composites for repair are diverse. Incorporating a combination of mechanical and chemical pre-treatments resulted in superior repair bond strength of resin composite materials under both short- and long-term simulated aging conditions. CLINICAL SIGNIFICANCE: The analysis of evidence revealed significant variability among protocols for repairing resin composites. Utilizing both mechanical and chemical pre-treatment methods is important for enhancing the bond strength of resin composites during both short- and long-term simulated aging situations.

Color and surface roughness alterations of bulk-fill resin composites submitted to simulated toothbrushing with whitening dentifrices

Aim: To evaluate the surface roughness and color stability of bulk-fill resin composites after simulated toothbrushing with whitening dentifrices. The radioactive/relative dentin abrasion (RDA) and radioactive/relative enamel abrasion (REA) of dentifrices were also assessed. Methods: Specimens (n=10) of Tetric N Ceram Bulk Fill (TNCB), Filtek One Bulk Fill (FOB) resin composites, and Z100(Control) were prepared using a cylindrical Teflon matrix. Surface roughness (Ra, µm) was assessed by a roughness meter and the color evaluations (ΔEab , ΔE00 , WID ) were performed using a digital spectrophotometer based on the CIELAB system. Three measurements were performed per sample, before and after simulated toothbrushing with 3D Oral-B White Perfection (3DW) and Black is White (BW) dentifrices. The abrasivity (REA and RDA values) of the used dentifrices was also determined by the Hefferren abrasivity test. Results: The Ra values increased significantly in all resin composites after 3DW and BW toothbrushing. The acceptable threshold color varied among resin composites, and TNCB and Z100 presented the highest ΔEab and ΔE00 for BW dentifrice. The 3DW dentifrice was significantly more abrasive than BW dentifrice on enamel and dentin. Conclusions: simulated toothbrushing with tested whitening dentifrices increased the surface roughness at acceptable levels. The Tetric N Ceram Bulk-fill and Z100 composite showed the highest color alteration in BW. 3D White Perfection dentifrice was more abrasive on dentin and enamel than Black is White.

Facetas em resina composta com fechamento de diastemas para harmonização do sorriso: relato de caso / Composite resin veneers with diastema closure for smile harmonization: A case report / Facetas de resina compuesta con cierre de diastemas para harmonización de la sonrisa: Informe de caso

Introdução:A estética do sorriso é um aspecto valorizado pela sociedade atual, o que demanda que os profissionais de odontologia estejam atualizados sobre materiais dentários e novas técnicas para alcançar resultados estéticos restauradores de alta qualidade. A resina composta é frequentemente utilizada para simplificar a reabilitação oral, pois oferece facetas dentárias que combinam excelente estética e durabilidade. Objetivo:Este artigo tem como objetivo relatar um caso clínico de reabilitação estética utilizando facetas em resina composta com fechamento de diastemas.Relato de caso:Uma paciente do sexo feminino, com 24 anos de idade, procurou a clínica escola de odontologia com insatisfação em relação à estética do seu sorriso. A pacienteapresentava diastemas, restauração defeituosa e desproporção no tamanho dos dentes anteriores. O tratamento consistiu em um clareamento caseiro prévio, seguido pela confecção de facetas diretas em resina composta para fechamento dos diastemas e correção da desproporção dentária. Foram utilizados um Jig Estético e o software Digital Smile Design (DSD)para o planejamento, além de um mock-up em resina bisacrílica. Após a confecção das facetas, foi obtido um resultado estético final satisfatório. O caso incluiu um total de oito facetas,dos dentes 14 ao 24. Conclusão:O tratamento utilizando restaurações em resina composta proporcionou à paciente uma reabilitação estética, funcional e biológica (AU).

Introduction:Smile aesthetics is an aspect valued by today's society, which demands that dental professionals are up to date on dental materials and new techniques to achieve high-quality restorative aesthetic results. Composite resin is often used to simplify oral rehabilitation, as it offers dental veneers which combine excellent aesthetics and durability. Objective:This article aims to report a clinical case of aesthetic rehabilitation using composite resin veneers with diastema closure. Case report:A24-year-old female patient came to the dental school clinic with dissatisfaction regarding the aesthetics of her smile. The patient had diastemas, defective restoration and disproportionate anterior teeth size. The treatment consisted of prior at-home tooth bleaching, followed by creating direct composite resin veneers to close the diastemas and correct tooth disproportion. An Aesthetic Jig and the Digital Smile Design (DSD) software program were used for planning, in addition to a mock-up in bisacrylic resin. After treatment, a satisfactory final aesthetic result was obtained. The case included a total of eight veneers, from teeth 14 to 24. Conclusion:Treatment using composite resin restorations provided the patient with aesthetic, functional and biological rehabilitation (AU).

Introducción: La estética de la sonrisa es un aspecto valorado por la sociedad actual, hecho que demanda de los profesionales de odontología actualización constante sobre los materiales dentarios y nuevas técnicas para alcanzar resultados estéticos restauradores de altacualidad. La resina compuesta es frecuentemente utilizada para simplificar la rehabilitación oral, pues ofrece facetas dentarias que combinan excelente estética y durabilidad.Objetivo: Este artículo tiene como objetivo relatar un caso clínico de rehabilitación estética a partir de la utilización de facetas en resina compuesta con cierre de diastemas. Informe de caso: Una paciente, del sexo femenino, con 24 años de edad, buscó la clínica-escuela de odontología insatisfecha con la estética de su sonrisa. La paciente presentaba diastemas, restauración dentaria defectuosa y desproporción en el tamaño de los dientes anteriores. El tratamiento consistió en un blanqueamiento casero previo, seguido por la confección de facetas directas de resina compuesta para cierre de los diastemas y corrección de la desproporción dentaria. Fueron utilizados un Jig Estético y el software Digital Smile Design(DSD) para el planeamiento, además de un mock-upen resina bisacrílica. Tras la confección de las facetas, fue obtenido un resultado estético final satisfactorio. El caso incluyó un total de ocho facetas, de los dientes 14 al 24.Conclusión: El tratamiento a partir de restauraciones en resina compuesta proporcionó a la paciente una rehabilitación estética, funcional y biológica (AU).

Effect of Hydrofluoric Acid Concentration on Bond Strength to Glass-Ceramics: A Systematic Review and Meta-Analysis of In-Vitro Studies.

PURPOSE: To conduct a systematic review and meta-analysis of in-vitro bond strength to glass-ceramics using hydrofluoric acid (HF) at lower (<5%) and higher (>5%) concentrations ([HF]) to treat ceramic surfaces. METHODS: Systematic searches were carried out in PubMed, Scopus, LILACS, and Web of Science for articles published through July 2021, and a meta-analysis was performed to estimate the combined effect by comparing the differences between the standardized means of the bond strengths of the evaluated materials. RESULTS: In total, 943 articles were found, of which 17 studies were selected for qualitative analysis and 12 for quantitative analysis. The bond strength to glass-ceramics using 4% to 5% HF did not differ from that using 7% to 10% HF for the following HF etching times and glass-ceramic materials: 20 s for lithium-disilicate (Z = 0.65, p = 0.51), 60 s for feldspathic (Z = 0.53, p = 0.60), and 60 s for leucite (Z = 0.72, p = 0.35). CONCLUSION: The lower concentration HF (<5%) etchant is a reliable surface treatment for adhesive bonding to glass-ceramics with satisfactory bond strength in short-term evaluations.

Effect of simulated brushing with dentifrices on surface roughness and the mass loss of acrylic resin: A systematic review and meta-analysis of in vitro studies.

STATEMENT OF PROBLEM: Brushing with dentifrice is the most commonly used denture cleaning method. However, it can result in the mass loss of acrylic resin and an increase in surface roughness, which favors the adherence of microorganisms. PURPOSE: The purpose of this systematic review and meta-analysis of in vitro studies was to assess the influence of simulated brushing by using dentifrices and water on surface roughness and the mass loss of acrylic resins. MATERIAL AND METHODS: Searches were performed in PubMed, Scopus, Web of Science, Lilacs, Embase, Open Gray, and Google Scholar databases in September 2022. The study selection process, data extraction, and risk of bias analysis were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The protocol of this systematic review was registered in the Open Science Framework (DOI number 10.17605/OSF.IO/QD4GH). Meta-analysis was performed by using a random effects model (α=.05) in the RevMan (Cochrane Collaboration) software program. RESULTS: A total of 14 studies were included in the qualitative synthesis and 2 studies in the quantitative synthesis. The manual toothbrush was the most analyzed (n=9), followed by the electric toothbrush (n=5) and denture brush (n=1). Denture base resin (n=8) was evaluated more than acrylic resin for the abrasiveness of toothpaste (n=6). Most studies used conventional toothpaste (n=12), whereas 6 used specific dentifrices. The period of brushing corresponding to 1 year was the most predominant (n=6). Surface roughness (n=13) was evaluated more than mass loss (n=4). In general, dentifrices resulted in greater surface roughness than water. According to meta-analysis results, brushing by using dentifrices reported higher mass loss values than brushing with distilled water (P<.05). CONCLUSIONS: Brushing acrylic resins with dentifrice was more abrasive than brushing with water.

Are polywave light-emitting diodes more effective than monowave ones in the photoactivation of resin-based materials containing alternative photoinitiators? A systematic review.

OBJECTIVE: This systematic review aimed to analyze if using polywave light-emitting diodes (LED) to photoactivate resin-based materials (resin composites, adhesive systems, and resin cements) containing alternative photoinitiators provide better physicochemical properties than monowave ones. MATERIAL AND METHODS: Inclusion criteria were in vitro studies that evaluated the degree of conversion, microhardness and flexural strength in resin-based materials containing alternative photoinitiators and light-activated with mono and polywave LEDs. Exclusion criteria were studies that evaluated the physicochemical properties of composites through any material interposed between the LED and the resin composite and studies that exclusively compared different modes and/or light activation times. Selection of studies, data extraction, and risk-of-bias analysis was performed. Data from selected studies were qualitatively analyzed. A systematic search was performed in June 2021 using PubMed/Medline, Embase, Scopus, and ISI Web of Science databases and grey literature without language restriction. RESULTS: A total of 18 studies were included in the qualitative analysis. Nine studies used diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (TPO) as an alternative photoinitiator for resin composite. Polywave LED improved the degree of conversion of resin composite compared to monowave in 9 of the included studies. Polywave LED improved the microhardness of resin composite compared to monowave in 7 of the included studies. Polywave LED improved the degree of conversion for 11 studies and microhardness of resin composite compared to monowave for 7 included studies. No differences in the flexural strength medium between poly and monowave LEDs were observed. The evidence was graded as low quality due to the high risk of bias for 11 studies. CONCLUSION: The existing studies, with their limitations, revealed that the polywave light-emitting diode maximizes activation, resulting in a higher degree of double-bond conversion and microhardness of resin composites containing alternative photoinitiators. However, the flexural strength of these materials is not influenced by the type of light activation device.

Bonding Efficacy of Universal Resin Adhesives to Zirconia Substrates: Systematic Review and Meta-Analysis.

PURPOSE: To provide an overview of the in-vitro bond strength of universal adhesives to zirconia and analyze whether these adhesives are a reliable alternative to conventional zirconia primers. MATERIALS AND METHODS: A systematic search was conducted in PubMed/Medline, Scopus, and ISI Web of Science databases up to August 2021. Investigations published in English, assessing resin-mediated bond to zirconia using universal adhesives compared to phosphate/silane-based primer or phosphate-based primer were included. After study selection and data extraction, risk of bias analysis was performed. Statistical analyses were performed using RevMan 5.4, with a random effects model, at a significance level of 0.05. RESULTS: In total, 23 studies were included for qualitative and quantitative analysis. Universal adhesives showed higher bond strengths than did phosphate-based primers (p < 0.00001) to aged zirconia without airborne alumina-particle abrasion. Similar results were observed when the zirconia surface was airborne-particle abraded at baseline and after dynamic aging (p < 0.0001). When universal adhesives and phosphate-silane based primers were compared, similar bond strengths (p ≥ 0.001) were observed after surface abrasion, regardless of storage condition. CONCLUSION: The results showed that universal adhesives generate higher bond strengths when compared to conventional zirconia primers.

Efetividade da ação clareadora dos dentifrícios no clareamento dental: uma revisão Integrativa / Effectiveness of teeth whitening action in dental bleaching: an Integrative review

Objetivo: Avaliar a efetividade dos dentifrícios categorizados como do tipo clareadores no clareamento dental, por meio de um levantamento da evidência científica. Métodos: Foram utilizadas as bases de dados eletrônicas Pubmed, Embase, Web of Science e Scopus para a busca dos estudos até o mês de agosto de 2021. Estudos clínicos que compararam os dentifrícios mencionados como clareadores com os dentifrícios não clareadores na mudança de cor dos dentes foram incluídos. As palavras-chaves utilizadas na estratégia de busca foram: "whiteningtoothpastes", "whiteningdentifrice", "toothpastes", "dentifrice", "color change", "colorationanalysis" e "toothbleaching". Os dados foram analisados por meio de uma síntese qualitativa, detalhando os principais resultados dos estudos incluídos. Após a etapa de leitura e seleção dos artigos, foram incluídos 5 artigos para essa revisão integrativa. Resultados: O creme dental mais utilizado foi o Close Up White Now (n = 3). A metodologia de cor mais utilizada foi a espectrofotometria, o tipo de estudo que predominou foi o ensaio clínico randomizado, avaliando o esmalte dental humano. No que se refere ao RDA (Relative Dentin Abrasitity), os dentifrícios clareadores apresentam um índice entre 60-100, por vezes superior à 100, sendo considerados abrasivos. Conclusão: Nos resultados de alguns estudos incluídos, os dentifrícios clareadores não apresentaram efeito de clareamento intrínseco, apenas o efeito de remoção de manchas extrínsecas foi observado.

Aim: To evaluate the effectiveness of dentifrices categorized as whitening in tooth whitening, through a survey of scientific evidence. Methods: The Pubmed, Embase, Web of Science, and Scopus electronic databases were used to search for studies up to August 2021. Clinical studies that compared dentifrices mentioned as whitening with non-whitening dentifrices in the change of tooth color were also included. The keywords used in the search strategy were: "whiteningtoothpastes", "whiteningdentifrice", "toothpastes", "dentifrice", "color change", "colorationanalysis", and "toothbleaching". Data were analyzed using a qualitative synthesis, detailing the main results of the included studies. After reading and selecting the articles, five articles were included in this integrative review. Results: The most used widely toothpaste was Close Up White Now (n = 3). The most commonly used color methodology was spectrophotometry, while the predominant type of study was the randomized clinical trial, evaluating human dental enamel. Regarding the RDA (Relative Dentin Abrasitity), whitening toothpastes have an index between 60-100, sometimes higher than the 100, and are considered abrasive. Conclusion: In the results of some of the included studies, whitening dentifrices did not have an intrinsic whitening effect; only the effect of removing extrinsic stains was observed.

Bond strength of bulk-fill resin composites: the effect of cavity preparation and aging

Aim: Evaluating the resin-dentin bond strength of Class II conventional and bulk-fill composite restorations, using different cavity sizes before and after aging. Methods: Seventy-five human molars were distributed into groups according to the buccolingual width of the cavities, conservative (n=25) and extended (n=50). They were divided according to the restorative material: conventional (Z100/control group) or bulk-fill resin composites (Filtek Bulk Fill/FBF; Tetric N Ceram Bulk Fill/TNCBF; Filtek Bulk Fill Flow/FBFF; Surefill SDR flow/SDR). The restored teeth were sectioned on sticks (n=50 per restorative materials + width cavities group), half were stored in Water/Ethanol 75% for 30 days and the other half were submitted to the immediate microtensile bond strength (µTBS) test. Data were analyzed applying the Three-Way Analysis of Variance (ANOVA), Bonferroni test, test t, and Weibull analyses (p<0.05). Results: SDR and FBF presented lower µTBSvalues for extended preparation when compared to the conservative preparation, before aging. After aging, only for the FBFF, a decrease in the µTBSvalues was observed. Comparing the µTBSvalues, before and after aging, the SDR demonstrated lower µTBSvalues after aging when the conservative cavity was used. A decrease in the µTBSvalues was observed for the Z100, the FBF and, the FBFF, after aging, when the extended cavity was used. Conclusion: The effect of cavity preparation and aging on the resin-dentin of Class II is material dependent. Most of the bulk-fill resin composites evaluated presented a similar performance to the conventional resin composites for all the conditions of this study

Effect of universal adhesives and self-etch ceramic primers on bond strength to glass ceramics: A systematic review and meta-analysis of in vitro studies.

STATEMENT OF PROBLEM: To simplify dental procedures, multicomponent products such as universal adhesives and self-etch ceramic primers have been recommended for glass-ceramic bonding; however, studies have shown a wide range of results. PURPOSE: The purpose of this systematic review and meta-analysis was to analyze the in vitro bond strength promoted by hydrofluoric acid+silane-containing universal adhesives and a self-etch ceramic primer to glass-ceramics and compare it with that of conventional treatments. MATERIAL AND METHODS: A systematic search was conducted in the PubMed/Medline, Scopus, LILACS, and ISI Web of Science databases up to April 2021. In vitro studies assessing the resin-mediated bond to glass-ceramics by using a self-etch ceramic primer and hydrofluoric acid+silane-containing universal adhesives and/or compared with traditional hydrofluoric acid+glass-ceramic primers were included. Selection of studies, data extraction, and risk-of-bias analysis were performed. Statistical analysis was performed by using a review management software program using a random effects model (α=.05). RESULTS: A total of 33 studies were included in the qualitative analysis and 26 studies in the quantitative analysis. Bond strength to lithium disilicate ceramic was higher when a hydrofluoric acid+glass-ceramic primer was used than when using a hydrofluoric acid+silane-containing universal adhesive (P<.05), except when 9% to 10% acid concentration was used in combination with static aging (P=.100). A self-etch ceramic primer promoted bond strength values to lithium disilicate that were similar to those of the hydrofluoric acid+glass-ceramic primer (P>.100). CONCLUSIONS: Hydrofluoric acid+silane-containing universal adhesive was not as effective as the hydrofluoric acid+glass-ceramic primer in promoting bond strength to glass-ceramic. Bond strength values generated by a self-etch ceramic primer to glass-ceramic were similar to those generated by the conventional treatment.

Bond strength of universal adhesive applied to dry and wet dentin: one-year in vitro evaluation

Aim: This study evaluated the influence of dentin wettability on the immediate and extended microtensile bond strength (mTBS) of a universal adhesive system used in the etch-and-rinse strategy. Methods: Twenty human third molars were selected and divided into four groups according to the adhesive system and dentin wettability. The mTBS values of each group were registered 24 h and one year after adhesive system application and resin composite block build-up (n=30). Data were analyzed by the t-test (p<0.05). Results: When both adhesive systems were compared, there was no statistically significant difference when they were applied following wet bonding (p>0.05). However, the dry bonding reduced µTBS values of the Adper Single Bond 2 adhesive (p<0.05). Regarding storage time, both groups presented similar µTBS values at 24 h and one year (p>0.05). Conclusions: Therefore, the Scotchbond Universal Adhesive can be applied to dry or wet dentin without compromising the etch-and-rinse bonding quality and the durability of the restorations

Effect of cleaning protocol on silica deposition and silica-mediated bonding to Y-TZP.

OBJECTIVES: To evaluate the effect of cleaning methods on the deposition of silica on yttria-stabilized zirconium dioxide (Y-TZP) surface and on the silane-silica mediated bond strength between Y-TZP and resin cement. METHODS: Y-TZP slabs were air-abraded with 30µm silica-coated alumina particles and distributed in three groups: no cleaning, cleaning with a stream of oil-free air/water spray for 5s and cleaning with an ultrasonic bath in water for 10min. The distribution of Si on the Y-TZP surfaces was recorded using energy dispersive spectroscopy (EDS). After the treatment was applied, Y-TZP slabs (n=20) received a primer application and resin cement cylinders were built on the surface. After storage (24h) in water storage or 3 months plus thermocycling; n=10), microshear bond strength test (µSBS) was performed. X- ray Photoelectron Spectroscopy (XPS) characterized the chemical bonds between the silica layer and the silane-containing primer. Data were analyzed using ANOVA and Tukey test, as well as Weibull analysis (α=0.05). RESULTS: Cleaning method had a significant effect on the amount of Si deposited on zirconia surface (p<0.001) and, consequently, on bond strength (p<0.001). Storage/aging also had a significant effect on bond strength (p<0.001). Low values of Weibull moduli for bond strength were observed for all groups after aging. XPS showed silane-silica chemical interaction for all groups. SIGNIFICANCE: The silica deposited by tribochemical coating to Y-TZP was removed by the cleaning methods evaluated, compromising bond strength. Stability of the bonding is also a concern when no cleaning method is applied.

Effect of silane and MDP-based primers on physico-chemical properties of zirconia and its bond strength to resin cement.

OBJECTIVE: To evaluate the effect of surface treatments on yttria-tetragonal zirconia polycrystal (Y-TZP) characteristics and on resin-mediated zirconia bond. METHODS: Y-TZP slabs were grit blasted with 45µm alumina or with 30µm silica-coated alumina particles. The chemical treatments were: no-chemical treatment (NC), silane-containing primer (SP), MDP (10-Methacryloyloxydecyl dihydrogen phosphate) and silane-containing primer (MPS), MDP-containing primer (MP) and MDP and silane-containing adhesive (MPA). Contact angle as a function of surface roughness (θm) and surface roughness parameter (Sdr) were measured using Fringe Projection Phase Shifting (FPPS). Surface free energy (γsTOT) was calculated with a goniometer. Chemical interaction between primers/adhesive and zirconia was analyzed using time-of-flight secondary ion mass spectrometry (ToF-SIMS). Resin cement microshear bond strength (µSBS) was analyzed at either 24-h or 8-months water storage (37°C). θm values, Sdr values, γsTOT and µSBS values were analyzed using Analysis of variance (ANOVA) and post hoc Tukey test (α=0.05). RESULTS: Chemical treatment had an effect (p<0.001) on all surface parameters analyzed: θm, γsTOT and Sdr. MP-treated group showed higher incidence of P-O-Zr bonds than the other groups, indicating more chemical linkages. Grit blasting (p<0.001) and the interaction chemical treatment*storage (p<0.001) did not affect µSBS; all silane-containing primers showed significant drop in µSBS after aging. SIGNIFICANCE: MDP and/or silane-based solutions affect the physicochemical properties of blasted-zirconia. An MDP-based primer is fundamental to achieve a stable resin-zirconia bonding, but the chemical reactivity of MDP is impaired when this molecule is present in a multicomponent system.

Effect of ionizing radiation on the properties of restorative materials.

AIM: The aim of this study is to evaluate the effect of different doses of the ionizing radiation (0 Gy, 10 Gy, 30 Gy, and 60 Gy) on the physical properties of dental materials. METHODOLOGY: Disc-shaped samples from each material (Ketac Molar Easymix, Vitro Molar, Vitremer, Vitro Fil Lc, Filtek Z 250 and Filtek Z 350) were made for water solubility, sorption analysis (n = 20), microhardness (n = 20), and surface roughness analysis (n = 24). Specimens were divided into four groups, according to radiation dose: control group (0 Gy), 10 Gy, 30 Gy, and 60 Gy. For water solubility and sorption analysis, the specimens were irradiated and were stored for 21 days to calculate the water solubility and sorption values. Microhardness analysis was carried out before and after irradiation doses. For surface roughness analysis, the specimens were submitted to brushing test, and after 24 h, initial surface roughness analysis was made in a rugosimeter. Subsequently, the samples were irradiated and final surface roughness analysis was made. The original water solubility and sorption, surface roughness, and microhardness values were subjected to ANOVA two-way statistical analysis and Paired t-test and Tukey post hoc test (α = 0.05), respectively. RESULTS: Water solubility and sorption values, and surface roughness values presented statistical difference between groups (0, 10, 30 e 60 Gy) for all materials. CONCLUSIONS: High doses of ionizing radiation (30 Gy and 60 Gy) increased the surface roughness, sorption, and solubility for the most materials.

Impact of radiotherapy on the bond strength of different adhesive systems to human dentin: one-year in vitro evaluation

Aim: The aim of this study is to evaluate the effect of radiotherapy on the bond strength of resin-based composite restorations to dentin, performed either 24 h or 1 year before or after radiation. Methods: Ninety-six posterior teeth were randomly distributed into the following groups: IB (n = 16), irradiated teeth were restored 1 year after x-ray application; NB (n = 16), not irradiated teeth were stored for 1 year and then restored. IA (n = 32), teeth were restored and irradiated at 24 h or 1 year after the restoration. NA (n = 32), teeth were restored, not irradiated, and tested as IA. Eight samples from each group were randomly assigned to either the three-step or two-step etch-and rinse adhesive system procedure. The irradiated specimens were subjected to 60 Gy of x-ray radiation fractionally. The restored teeth were vertically sectioned, and 1-mm2 resin­dentin sticks were obtained and submitted to the microtensile bond strength test. The bond strength data were analyzed by two-way analysis of variance (ANOVA) followed by Tukey's test (p < 0.05). Failure modes were examined by optical microscopy and scanning electron microscopy. Results: The IB group showed lower bond strength values compared to the NB group. The bond strength values between the adhesive systems were not statistically different. Conclusion: The application of radiation dose decreased the bond strength of the adhesive restorations to dentin when the bonding procedure was conducted 1 year after in vitro radiotherapy

Depth of cure of bulk fill resin composites: A systematic review.

OBJECTIVE: To evaluate scientific evidence regarding depth of cure of bulk-fill resin composites (BFRCs) and related factors. MATERIAL AND METHODS: PubMed/Medline, Embase, Scopus, and ISI Web of Science databases were accessed from October 2016 to May 2017. Investigations published in English language, assessing depth of cure of BFRCs by microhardness test and/or degree of conversion (DC) were included. Studies using exclusively ISO 4049, employing specimens deepness less than 4 mm, as well as those not reporting exposure time and/or irradiance from light curing units (LCUs) were excluded. RESULTS: In total, 742 studies were found from which 33 were included. From 21 studies evaluating BFRCs microhardness, 10 showed acceptable bottom/top ratios (≥0.8) for all tested materials. However, material-dependent results and non-satisfactory bottom/top microhardness ratios (<0.8) were reported in 9 and 2 investigations, respectively. From 19 studies that assessed DC, 11 showed acceptable results (≥50%) for all tested BFRCs, while 8 studies reported material-dependent outcomes. Overall, irradiance from LCUs ranged from 650 to 1330 mW/cm2 and exposure time from 5 to 60 seconds. Favorable depth of cure results were observed with the use of LCUs emitting irradiance ≥1000 mW/cm2 and exposure times ≥20 seconds. CONCLUSIONS: High depth of cure rates by BFRCs, depends on some factors as material, irradiance and exposure time. Polywave LCUs were useful but not essential on polymerizing alternative photoinitiator-containing BFRC. CLINICAL SIGNIFICANCE: LED curing devices (polywave or monowave) displaying an irradiance ≥1000 mW/cm2 and 20 seconds of exposure time are imperative to accomplish successful polymerization of most BFRCs.

The effect of a bleaching agent on the pigment removal and the bond strength of bulk-fill resin composites: an in vitro study / Efeito dos agentes clareadores na remoção de pigmentos e na resistência de união de resinas compostas bulk-fill: um estudo in vitro

Introduction: In order to simplify the technique, reduce the time required for direct adhesive restorations, bulk-fill resin composites have been developed be applied in bulk placement up to 4 mm increments. Objective: Evaluating the color change (ΔE) and the microtensile bond strength (μTBS) of bulk fill resin composites (BFRC) to dentin after the immersion in regular beverages and the application of bleaching systems. Method: Forty-five human molar teeth were randomly distributed in three groups according to the filling material (n=15): Filtek Bulk Fill, Tetric N Ceram Bulk Fill and Filtek Z100. The restored teeth were immersed in coffee, wine and distilled water (n=5) for 72 hours. The color parameters were measured using a spectrophotometer, having as basis the CIE L*a*b*, before and after tooth staining and application of bleaching processes. Subsequently, the teeth were sectioned to obtain the specimens for the microtensile testing. The ΔE values were analyzed applying the Kruskal-Wallis and the Wilcoxon tests, and the μTBS values were analyzed applying the ANOVA and the Bonferroni tests (p<0.05). Result: There were no significant differences in the ∆E values when comparing the BFRCs to the conventional resin composite (CRC) in most of the experimental groups. The ∆E values did not present significant differences before and after the application of bleaching processes for all the tested resin composites. The BFRCs presented higher μTBS values than the CRC after exposure to distilled water, wine and bleaching agent. Conclusion: The studied BFRCs presented similar color stability to the CRC. The BFRCs presented higher bond strength to the dentin than the CTC in most of the evaluated conditions. The bleaching agent was not effective in whitening the stained restored teeth.

Introdução: Em busca de simplificar a técnica, reduzir o tempo requerido para as restaurações adesivas, resinas compostas bulk-fill (RCBF) estão sendo desenvolvidas para serem aplicadas em incrementos com espessura de até 4 mm. Objetivo: Avaliar a alteração de cor (ΔE) e resistência de união (μTBS) de RCBF a dentina após imersão em bebidas e aplicação de um sistema clareador. Método: Foram utilizados 45 dentes molares humanos que foram distribuídos aleatoriamente em três grupos de acordo com o material restaurador (n=15): Filtek Bulk Fill, Tetric N Ceram Bulk Fill e Filtek Z100. Os dentes restaurados foram imersos em café, vinho e água destilada (n=5) durante 72 horas. Os parâmetros de cor foram mensurados utilizando um espectrofotômetro, tendo como base o CIE L*a*b*, antes e após o manchamento e aplicação dos agentes clareadores. Consequentemente, os dentes foram seccionados para a obtenção de espécimes para o teste de microtração. Os valores de ΔE foram analisados aplicando os testes de Kruskal-Wallis e Wilcoxon e os valores de μTBS foram analisados aplicando ANOVA e o teste de Bonferroni (p<0,05). Resultado: Não houve diferença significante nos valores de ∆E quando as RCBFs foram comparadas a resina composta convencional (RCC) na maioria dos grupos experimentais. Os valores de ∆E não apresentaram diferença estatística antes e após a aplicação do agente clareador para todas as resinas testadas. As RCBFs demonstraram maiores valores de μTBS comparado a RCC após exposição a água destilada, vinho e agente clareador. Conclusão: As RCBFs demonstraram uma similar estabilidade de cor quando comparado a RCC. As RCBFs apresentaram maior resistência de união a dentina que a RCC na maioria das condições avaliadas. O agente clareador não foi efetivo no clareamento dos dentes restaurados.

Water sorption and solubility of glass ionomer cements indicated for atraumatic restorative treatment considering the time and the pH of the storage solution / Sorção de água e solubilidade de cimentos de ionômero de vidro indicados para tratamento restaurador atraumático em função do tempo e do pH da solução de armazenagem

ABSTRACT Objective: Evaluate the water sorption and the solubility of glass ionomer cements considering the time and the pH of the storage solution. Methods: The materials used in this survey study were the following ones: Ketac Molar Easymix, Maxxion R, Vitro Molar, Vitremer and Vitro Fil LC. Fifteen specimens of each material were fabricated and subdivided into the storage solutions (deionized water, acid artificial saliva and neutral artificial saliva), having the mass measured in 24 hours, 7, 14 and 21 days. Water sorption and solubility values (µg/mm3) were obtained and submitted to the analysis of variance (ANOVA) and the Tukey test (p <0.05). Results: The water sorption values were statistically different for all the studied materials and solutions in each storage period, except for the Maxxion R. Considering the solubility, all the glass ionomer cements presented values that were not statistically different when evaluating the storage solutions, except for the Vitro Fill LC. Conclusion: The water sorption and the solubility of the studied glass ionomer cements were not influenced by the various storage solutions.

RESUMO Objetivo: Avaliar a sorção de água e a solubilidade de cimentos de ionômero de vidro em função do tempo e do pH da solução de armazenagem. Métodos: Os materiais utilizados foram: Ketac Molar Easymix, Maxxion R, Vitro Molar, Vitremer e Vitro Fil LC. Foram confeccionados 15 espécimes de cada material que foram subdivididos nas soluções de armazenamento (água deionizada, saliva artificial ácida e saliva artificial neutra) e tiveram suas massas mensuradas em 24 horas, 7, 14 e 21 dias. Os valores da sorção de água e solubilidade (µg/mm3) foram obtidos e submetidos à análise de variância (ANOVA) e ao teste de Tukey (p<0,05). Resultados: Os valores de sorção de água diferiram estatisticamente para cada período de armazenamento para todos os materiais e soluções estudadas, exceto para o Maxxion R. Em relação à solubilidade, todos os cimentos de ionômero de vidro apresentaram valores que não diferiram estatisticamente comparando as soluções de armazenamento, exceto o Vitro Fill LC. Conclusão: A sorção de água e a solubilidade dos cimentos de ionômero de vidro estudados não sofreram influência dos diferentes meios de armazenagem.

Avaliação da rugosidade superficial e análise morfológica de cimentos de ionômero de vidro: influência do armazenamento em saliva artificial / Evaluation of surface roughness and morphological analysis of glass ionomer cements: influence of storage in artificial saliva

Introdução: O desenvolvimento dos cimentos de ionômero de vidro (CIVs) proporcionou vantagens aos procedimentos restauradores diretos devido a suas propriedades, como adesão química à estrutura dentária e liberação de flúor. No entanto, o ambiente bucal pode promover condições capazes de alterar a superfície deste material. Objetivo: Avaliar a rugosidade superficial e a morfologia de superfície de quatro cimentos de ionômero de vidro (Ketac Molar Easy Mix, Vitremer, Vitro Molar e Maxxion), quando imersos em diferentes soluções de saliva artificial. Material e método: Dez amostras de cada material foram confeccionadas e a rugosidade superficial foi avaliada antes e após imersão em saliva artificial ácida e neutra, durante 28 dias, por meio de um rugosímetro (Surftest SJ - 40), e a análise morfológica deu-se através de microscopia eletrônica de varredura. Os valores médios de rugosidade foram submetidos aos testes de Kruskal-Wallis e de Wilcoxon, além do teste de Mann Whitney, com nível de significância de 5%. Resultado: Os valores de rugosidade foram maiores estatisticamente após a imersão em saliva ácida e neutra para todos os materiais, exceto o Vitromolar, que não apresentou diferença estatística entre as médias de rugosidade antes e após imersão em saliva neutra. O Maxxion R apresentou estatisticamente maiores valores de rugosidade quando comparado aos outros materiais após imersão em saliva neutra e ácida. Conclusão: A rugosidade superficial dos cimentos de ionômero de vidro aumentou após imersão em saliva neutra e ácida para a maioria dos cimentos estudados. A solução de armazenagem ácida promoveu aumento da rugosidade superficial para o Maxxion R e o Vitro Molar.

Introducion: The development of glass ionomer cements brought advantages to direct restorative procedures due to properties such as chemical adhesion to dental structure and fluoride release. Nevertheless, oral environment may provide conditions which can alter material surface. Objective: To evaluate surface roughness and surface morphology of four glass ionomer cements (Ketac Molar Easy Mix, Vitremer, Vitro Molar e Maxxion) when immersing on different artificial saliva. Material and method: Ten specimens of each material were fabricated and surface roughness was measured before and after immersion on neutral and acid artificial saliva for 28 days using a rugosimeter (Surftest SJ–40) and microscopy analysis by scanning electron microscopy. Roughness data were analyzed statistically by Kruskal-Wallis test, Wilcoxon test and Mann Whitney test, at 5% significance level. Result: Roughness values were statistically higher after immersion on neutral and acid artificial saliva for all materials, except for Vitromolar that did not presented no statistical difference between roughness values before and after immersion on neutral saliva. The Maxxion R presented statistically higher roughness values compared to all materials after immersion on neutral and acid artificial saliva. Conclusion: The superficial roughness of glass ionomer cement increased after immersion on neutral and acid artificial saliva for most of the materials. Acid storage solution promoted a greater increase in surface roughness after immersion of the specimens for Maxxion and Vitro Molar.