One-year follow-up of microscopical and clinical behavior of bioactive self-etching resin sealant.

Background: The development of early carious lesions can be prevented with the use of sealants. This study aimed to evaluate the retention and sealant quality of conventional and bioactive self-etching sealants by direct (clinical) and indirect (microscopical) assessment. Materials and Methods: Sixty newly erupted mandibular second molars (International Caries Detection and Assessment System ≤2) from adolescents were selected for the split-mouth trial study. The tooth was randomized and treated with conventional Fluoroshield (FS) and BeautiSealant (BS) bioactive self-etching sealants. Molds were taken and cast with epoxy resin after treatment. Indirect and direct assessments of retention degree and sealant remnant quality were performed after baseline, 1 month, and 1 year. The Chi-square test, ordinal regression, reasons of chance, and Fleiss' kappa statistical test were employed. Results: After 1 month, greater total retention was observed for FS, but 1-year follow-up demonstrated no retention difference for FS and BS. The odds ratios showed an 86% greater chance of FS showing better marginal adaptation, after 1 month. At 1 year, the clinical assessment showed better anatomical shape and marginal adaptation scores for FS, but no microscopical difference was observed. A pour agreement between clinical and microscopical data was observed. Conclusions: The 1-year follow-up showed no significant difference in the degree of retention, and in the microscopic evaluation of the conventional sealant (FS) and the bioactive self-etching sealant (BS), but in the clinical evaluation, better marginal and anatomical adaptation scores for FS were observed.

Effect of Bioactive Filler Addition on the Mechanical and Biological Properties of Resin-Modified Glass Ionomer.

The maintenance of affected dentin can promote the greater conservation of tooth structure. The development of materials that have properties capable of reducing the demineralizing potential and/or even helping in dental remineralization is important for conservative dentistry. This study aimed to evaluate, in vitro, the alkalizing potential, fluoride as well as calcium ion release ability, antimicrobial activity, and dentin remineralization properties of resin-modified glass ionomer cement (RMGIC) incorporated with a bioactive filler (niobium phosphate (NbG) and bioglass (45S5)). The study samples were grouped into RMGIC, NbG, and 45S5. The materials' alkalizing potential, ability to release calcium as well as fluoride ions, and antimicrobial properties concerning Streptococcus mutans UA159 biofilms were analyzed. The remineralization potential was evaluated using the Knoop microhardness test, which was performed at different depths. The alkalizing and fluoride release potential was higher for the 45S5 group (p < 0.001) over time. An increase in the microhardness of demineralized dentin was observed in the 45S5 and NbG groups (p < 0.001). No differences in biofilm formation were observed between the bioactive materials, although 45S5 exhibited lower biofilm acidogenicity at different time points (p < 0.001) and greater calcium ion release in the microbial environment. A resin-modified glass ionomer cement enriched with bioactive glasses, particularly 45S5, is a promising alternative for the treatment of demineralized dentin.

Resin-modified glass ionomer enriched with BIOGLASS: Ion-release, bioactivity and antibacterial effect.

Developing dental materials for the prevention of remineralization or demineralization is important for high-risk caries patients. This study aimed to evaluate the physicochemical and microbiological effects of adding 45S5 bioglass to resin-modified glass ionomer cement (RMGIC). Samples belonged to the following groups: GIC: conventional glass ionomer cement (Vitro Fil), RMGIC: resin-modified GIC (Vitro Fil LC), and RMGIC/45S5: RMGIC with 10% (wt %) of 45S5. Changes in pH and release of fluoride, calcium, and phosphorus ions under acidic (pH 4) and neutral (pH 7) pH conditions were evaluated. Antibacterial activity was verified based on colony-forming units. Material sorption and solubility were analyzed after bacterial exposure. After 28 days, the bioactivity of the materials was evaluated using scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Analysis of variance, post hoc Scheffe, and Tukey (α = 0.05) tests were employed for statistical analysis. RMGIC/45S5 showed higher alkalization activity, calcium release at pH 4 and 7, and sorption than GIC and RMGIC (p < .05). Release of phosphorus and fluoride at pH 4 and 7 was higher for GIC than that for RMGIC and RMGIC/45S5 (p < .05). RMGIC/45S5 showed higher values than RMGIC (p < .05). However, antibacterial activity did not differ among the groups. Precipitates of calcium and phosphorus were visualized in RMGIC/45S5 samples via SEM/EDS. These results indicate that the RMGIC/45S5 promotes alkalization and increases the release of calcium, phosphorus, and fluoride ions, resulting in precipitate deposition rich in calcium and phosphorus, thereby being a promising option to improve the bioactivity of RMGIC.

In vitro and in vivo performance of self-conditioning sealants with pre-reacted glass for caries prevention.

Bioactive materials capable of preventing the development of caries lesions can be an important preventive strategy. This study aims to evaluate in vitro the alkalizing potential, fluoride release, shear bond strength (SBS), and Knoop microhardness (HK) of self-conditioning sealants with pre-reacted glass (S-PRG) and in vivo their retention, quality and caries prevention using the randomized clinical trial (RCT). Dental sealants FS-conventional (Fluoroshield-Dentsply) and BS self-etching (BeautiSealant-Shofu) were evaluated. Sealants samples (n = 5 per group) were performed to verify the alkalizing potential and fluoride release at neutral and acid pH. For mechanical evaluation of both sealants, twenty bovine incisors were used for SBS test, and twenty sealant samples were performed for HK under 50 g load for 15 s. All measurements were taken after 24h and 30 d. A split-mouth RCT including 28 volunteers (10-14 years) with erupted permanent molars and initial enamel caries lesions was conducted to evaluate BS and FS behavior. Sealant retention (total, partial and total loss) and quality scores were analyzed after 30 d. In vitro and in vivo tests were assessed by T-test, and χ2 & Fisher tests (α = 0.05). BS demonstrated higher alkalinizing potential at neutral and acid pH and lower SBS and HK at 24h and 30 d (p < 0.05). However, the FS had greater fluoride release at neutral and acid pH. Clinically, BS also showed lower retention than FS (p = 0.02), but no sealant quality difference was observed. Both sealants contributed to the remission or non-evolution of caries. After 1 month, the bioactive S-PRG sealant showed in vitro a higher alkalizing potential and lower fluoride release, retention, and microhardness, while in vivo, despite the lower retention, the non-evolution of caries lesions was verified.

Bioactive self-etching sealant on newly erupted molars: A split-mouth clinical trial.

OBJECTIVES: This randomized clinical trial compares retention, survival rate, and evolution of caries of newly erupted permanent molars sealed with bioactive self-etching sealants with pre-reacted glass ionomer (S-PRG). METHODS: A split-mouth clinical trial was conducted with 56 permanent second molars in stages 2 and 3 of crown eruption; ICDAS (International Caries Detection and Assessment System) was between 0 and 2. The molars were randomized and blinded in relation to the side (right or left) that would receive the sealants; the conventional resin sealant (FS), Fluroshield (Dentsply), or bioactive self-etch sealant (BS), BeautiSealant with S-PRG (Shofu). The sealants were compared in terms of retention, quality of sealant remnant (anatomical shape, marginal adaptation, surface texture, and marginal discoloration), and development of caries by ICDAS after 1, 6, and 12 months. The Wilcoxon, x² of independence, Kaplan-Meier, and Mantel-Cox survival statistical tests were applied (α = 5%). RESULTS: The total retention was higher for FS (57.1%) at all periods, and there was no difference in the quality of sealants at all periods. The ICDAS decreased after 6 (p = 0.025) and 12 months (p = 0.027) for both materials. Despite the lower retention of BS, the clinical quality of sealants over 12 months were similar. CONCLUSION: Teeth sealed with BS presented higher sound teeth predominance (ICDAS 0) compared to FS sealant, even with a higher loss of material. CLINICAL RELEVANCE: Eruption of permanent molars is a relevant period, and the prevention/management of initial caries is essential in these critical stages. Sealants can be an important prevention strategy. After 12 months of follow-up, there was a major failure of the bioactive sealant but without the development of caries lesions.

Interaction effect of Nd:YAG laser and universal adhesive system for dentin sealing.

BACKGROUND: To evaluate the influence of the association of the universal adhesive system to different energy densities of the Nd:YAG laser on the hydraulic conductance of dentin. MATERIAL AND METHODS: Fifty bovine dentin discs were made. The samples were stratified into four groups (n = 10) according to the treatment performed; SBU- Adper Single Bond Universal (3M ESPE), SBU_60 - SBU associated with the Nd:YAG laser (60mJ, 10Hz, 0.6W - 47.77 J / cm²), SBU_80 - SBU associated with the Nd:YAG laser (80mJ, 10Hz, 0.8 W - 63.69 J / cm2) and C - dentin without treatment (smear layer). Hydraulic conductance measurements were taken 24 hours after the treatments (HC1) and after erosive challenge (HC2). Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX) helped to visualize the dentin after the different treatments. Scheffe and Games-Howell statistical tests were used to analyze hydraulic conductance (α = 0.05). RESULTS: The treated dentin (SBU, SBU_60, and SBU_80) reduced HC1 when compared to dentin with smear layer (C) (p< 0.001). The erosive challenge has increased HC2 in SBU_60 and C (p< 0.001), and did not promote a significant difference in SBU_80 and SBU. The SEM / EDX analyzes showed an irregular and semi-permeable barrier on the surfaces of the treated dentin. CONCLUSIONS: The association of universal adhesive with Nd:YAG can be an effective alternative for the occlusion of dentinal tubules, whereas higher energy per pulse Nd:YAG (SBU_80) can increase the resistance to permeability when exposed to the erosive challenge. Key words:Dentin, permeability of dentin, Nd:YAG Laser, adhesives.

Could sonic delivery of bulk-fill resins improve the bond strength and cure depth in extended size class I cavities?

BACKGROUND: The implementation of restorative procedures that guarantee success and optimize clinical time is the target of investigations in Restorative Dentistry. This study aimed to analyze the influence of sonic insertion of bulk-fill (BF) and conventional (C) resin composites on the microtensile bond-strength (µ-TBS) and cure depth (CD) of large and deep class I restorations. MATERIAL AND METHODS: Fifty-six healthy human premolars were selected and occlusal cavities (4 x 4 x 3 mm; factor C = 5) were prepared. TC - Tetric N-Ceram (BF), SF - SonicFill (BF), and Z350 - Filtek Z350 XT (C) composite resins were used to restore the cavities, using sonic (S) and non-sonic (NS) insertion techniques. A group restored with conventional incremental insertion (I) using Z350 XT resin was performed serving as a control. Teeth were prepared for microtensile bond-strength test (µ-TBS). And also, restoration depths of 1 and 4 mm were measured with an automatic microhardness indenter (50 g -15 s) to determine the CD. Results were evaluated using ANOVA, Scheffe, and Games-Howel posthoc test (α = 0.05). RESULTS: Types of resins and insertion techniques present statistical differences for µ-TBS and CD (p ≤ 0.001). The µ-TBS was higher respectively for the groups SF > TC > Z350; however, the sonic insertion for SF and Z350 (I) did not present significant differences in µ-TBS. Higher microhardness values were observed on the surface (1mm). At a depth of 4 mm Z350 (I)> SF(S)> SF(NS)> TC(S/NS)> Z350(S/NS) (p< 0.001). Pearson's Correlation of bond strength and base micro-hardness was significant (p ≤ 0.001), strong, and positive (0.955). CONCLUSIONS: The influence of sonic insertion is material dependent, influenced only the microhardness of the SonicFill resin and did not interfere with the bond strength and cure depth of other bulk fill and conventional resin composite. Key words:Composite resins, dentin, hardness tests, tensile strength, Bulk-fill resins, sonic insertion.

Effect of bioactive glasses and neodymium:yttrium-aluminum-garnet laser on dentin permeability.

CONTEXT: Dental hypersensitivity and loss of dental tissues are commonly observed in patients, and most of the problems are caused due to total or partial exposure of dentinal tubules. AIMS: The purpose of this study is to evaluate the performance of 45S5 bioactive glass and niobophosphate (NbG) associated with neodymium: yttrium-aluminum-garnet (Nd:YAG) laser for the reduction of dentin permeability. MATERIALS AND METHODS: Fifty bovine dentin discs were made and distributed randomly into five groups (n = 10). The Nd:YAG laser was applied with the bioactive glasses using the energy parameters (60 and 80 mJ), forming the groups; NbG_60: NbG + Nd:YAG (60 mJ); NbG_80: NbG + Nd:YAG (80 mJ), 45S5_60: 45S5 + Nd:YAG (60 mJ); 45S5_80: 45S5 + Nd:YAG (80 mJ) and C: control (untreated dentin). The permeability was measured with a split chamber device. The samples were subjected to the erosive challenge and a new permeability measurement was done. Furthermore, the dentin was analyzed by scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). STATISTICAL ANALYSIS USED: The data were analyzed using Kruskal-Wallis and Dunn's tests (α = 0.05). RESULTS: Greater reduction in dentinal permeability was observed for 45S5 bioactive glasses (45S5_60 and 45S5_80) followed by NbG_80 and NbG_60 (P < 0.05). The SEM/EDS analysis showed the formation of a barrier after the dentin treatment. CONCLUSIONS: Bioactive glasses with Nd:YAG laser on the dentin surface may be a promising alternative for the reduction of dentin permeability.

Polymerization Shrinkage of Bulk Fill Composites and its Correlation with Bond Strength.

The present study aimed to evaluates polymerization shrinkage (PS) using microcomputed tomography (µCT) and microtensile bond strength (µTBS) in bulk fill composites (BFC) and conventional class I restorations as well as the correlation between these factors. Class I cavities (4 x 5 x 4 mm), factor-C = 4.2, were created in third molars that were free of caries, which were randomly divided in 4 groups (n = 6): XTI (Filtek Supreme XTE: incremental technique); XTB (Filtek Supreme XTE: single fill technique); TBF (Tetric Bulk Fill); and SF (SonicFill). Each tooth was scanned twice in µCT: T0 was after filling the cavity with composite, and T1 was after light curing. The data were analyzed by subtracting the composite volume for each time (T1 - T0). After 1 week, the teeth were sectioned crosswise in the buccolingual and mesiodistal directions to obtain specimens with approximately 1 mm² thickness and fixed in a universal testing machine to perform µTBS. The Kruskal-Wallis and Dunn tests showed a statistically significant difference for shrinkage in µCT among the XTI and XTB and between the SF and XTB. Regarding the µTBS, all the groups differed from XTB. Bulk fill composites type presents a PS similar to that of the conventional nanoparticulate composite inserted using the incremental technique, but the bond strength was higher for the incremental group, which presented a lower number of pre-test failures when compared to BFC. No correlation was observed between the polymerization shrinkage and bond strength in the studied composites.

Polymerization shrinkage of bulk fill composites and its correlation with bond strength

Abstract The present study aimed to evaluates polymerization shrinkage (PS) using microcomputed tomography (μCT) and microtensile bond strength (μTBS) in bulk fill composites (BFC) and conventional class I restorations as well as the correlation between these factors. Class I cavities (4 x 5 x 4 mm), factor-C = 4.2, were created in third molars that were free of caries, which were randomly divided in 4 groups (n = 6): XTI (Filtek Supreme XTE: incremental technique); XTB (Filtek Supreme XTE: single fill technique); TBF (Tetric Bulk Fill); and SF (SonicFill). Each tooth was scanned twice in μCT: T0 was after filling the cavity with composite, and T1 was after light curing. The data were analyzed by subtracting the composite volume for each time (T1 - T0). After 1 week, the teeth were sectioned crosswise in the buccolingual and mesiodistal directions to obtain specimens with approximately 1 mm² thickness and fixed in a universal testing machine to perform μTBS. The Kruskal-Wallis and Dunn tests showed a statistically significant difference for shrinkage in µCT among the XTI and XTB and between the SF and XTB. Regarding the μTBS, all the groups differed from XTB. Bulk fill composites type presents a PS similar to that of the conventional nanoparticulate composite inserted using the incremental technique, but the bond strength was higher for the incremental group, which presented a lower number of pre-test failures when compared to BFC. No correlation was observed between the polymerization shrinkage and bond strength in the studied composites.

Resumo O presente estudo teve por objetivo avaliar a contração de polimerização (CP) usando microtomografia computadorizada (µCT) e a resistência de união por microtração (µTBS) em restaurações classe I de compósitos bulk fill (CBF) e convencional, assim como a correlação entre esses fatores. Cavidades classe I (4 x 5 x 4 mm), fator C=4,2, foram feitas em terceiros molares livres de cárie que foram randomizados e divididos em 4 grupos (n = 6): XTI (Filtek Supreme XTE: técnica incremental); XTB (Filtek Supreme XTE: técnica de preenchimento único); TBF (Tetric Bulk Fill); E SF (SonicFill). Cada dente foi escaneado duas vezes em μCT: T0 -após o preenchimento da cavidade com compósito, e T1 - após a cura à luz. Os dados foram analisados subtraindo o volume do compósito para cada tempo (T1 - T0). Após 1 semana, os dentes foram seccionados transversalmente no sentido vestíbulo-palatino e mesio-distal para obter espécimes com aproximadamente 1 mm² de espessura e fixados em uma máquina de ensaio universal para teste de μTBS. Os testes de Kruskal-Wallis e Dunn mostraram diferença estatisticamente significante para a contração em μCT entre XTI e XTB, e entre SF e XTB. Em relação à μTBS, todos os grupos diferiram do XTB. Compósitos do tipo bulk fill apresentam uma CP similar ao compósito convencional nanoparticulado inserido usando a técnica incremental, porém a resistência de união foi maior para o grupo incremental, que apresentou um menor número de falhas pré-teste quando comparado aos CBF. Não foi observada correlação entre a contração de polimerização e a resistência de união nos compósitos estudados.

Is there correlation between polymerization shrinkage, gap formation, and void in bulk fill composites? A µCT study.

This in vitro study aimed to evaluate the volume of polymerization shrinkage (VS), gap (VG), and void (VV) using computerized microtomography (µCT) in bulk fill resin composites and conventional class I restorations, and to establish a correlation between these factors. Class I cavities (4 x 5 x 4 mm), C-factor = 4.2, were performed on caries-free human third molars and randomly divided into five groups (n = 6): FSI (Filtek Supreme XTE incremental insertion); FSS [(Filtek Supreme XTE single insertion(SI)]; TBF [(Tetric Bulk Fill: SI and manual filling (MF)]; SFM (Sonic Fill: SI/MF); and SFS (SonicFill: SI and sonic filling). The teeth were scanned and analyzed by µCT at T0, after filling the cavity with resin, and at T1, after polymerization for VG and VV, and for VS (T1-T0). There was statistically significant difference in VS in µCT for the FSI and FSS groups and between SFS and FSS as well as some difference in VV for FSI and bulk fill resin composites and no difference in VG between the conventional technique and bulk fill composites. Bulk fill resin composites presented similar VS and gap formation to those of incrementally inserted conventional resin composites. There is a moderate and weak positive correlation between polymerization shrinkage and gap formation and void, respectively. The final gap formation was more dependent on the initial gap than on polymerization shrinkage or void volume.

Shear bond strength of different surface treatments in bulk fill, microhybrid, and nanoparticle repair resins.

OBJECTIVES: The purpose of this study was to evaluate the influence of surface treatment and different types of composite resin on the microshear bond strength of repairs. MATERIALS AND METHODS: Seventy-two specimens (n=72) were prepared using a nanoparticle resin and stored in artificial saliva at 37 ± 1°C for 24 h. After this period, the specimens (n=24) were restored with microhybrid resin P60 (3M ESPE), nanoparticle resin Filtek Z350 (3M ESPE), and Bulk Fill Surefil SDR Flow (Dentsply) composite resins. Previously, the surfaces of the samples were treated, forming the following subgroups (n=12): (A) conditioned with 37% phosphoric acid for 30 s, and (B) abrasioned with a diamond tip for 3 s and conditioned with 37% phosphoric acid. In all groups, before insertion of the composite resin, the adhesive system Adper Single Bond 2 was actively applied and photopolymerized for 20 s. RESULTS: The microshear test was executed to assess bond strength. Kruskal-Wallis (p<0.05) and Mann-Whitney statistical tests showed significant statistical difference considering that the bulk-fill resin turned out to have a lower bond strength than the conventional nanoparticle and microhybrid composites. With regard to the technique, the roughening with diamond bur followed by the application of phosphoric acid exhibited values higher than the exclusive use of acid. CONCLUSION: The microshear bond strength of the composite resin repairs varies in accordance with the type of composite resin utilized, and roughening the surface increased the bond strength of these materials.

Er:YAG pre-treatment for bonding of orthodontic bracket: 1 year of in vitro treatment.

OBJECTIVE: The aim of this study was to evaluate in vitro bond strength of metal brackets bonded with: total etch, total etch with erbium: yttrium aluminum garnet laser (Er:YAG) and self-etching adhesive systems, submitted to thermal-mechanical cycling, simulating 1 year of orthodontic treatment. MATERIALS AND METHODS: For the study, 80 bovine incisors were randomly divided into 3 experimental groups (n=16 each): XT- acid etching + Transbond XT, XT/Er:YAG- Transbond XT associated with Er:YAG laser irradiation (λ=2.94 µm, 60 mJ, 10 Hz) and SEP- Transbond Plus Self Etching Primer. Samples were submitted to thermal-mechanical cycling, simulating 1 year of orthodontic treatment. Afterward, the shear bond strength test was performed in a universal test machine at a speed of 0.5mm/min. Samples were evaluated under a stereomicroscope and by scanning electron microscopy for analysis of enamel surface and adhesive remnant index. Data were analyzed using Kruskal-Wallis and Mann-Whitney (with Bonferroni correction) statistical tests. RESULTS: Statistically significant difference was observed between the groups studied (p<0.05). Groups XT and SEP showed the highest bond strength values, without statistical difference between them, while group XT/Er:YAG showed reduction in bond strength values. Higher frequency of adhesive failures between enamel and adhesive system was verified for groups XT and XT/Er:YAG. CONCLUSION: The conventional (XT) and self-etching (SEP) adhesive systems showed mean bond strength values, similar between them, whereas the previous application of Er:YAG laser promoted the lowest bond strength values.

Is there correlation between polymerization shrinkage, gap formation, and void in bulk fill composites? A µCT study

Abstract: This in vitro study aimed to evaluate the volume of polymerization shrinkage (VS), gap (VG), and void (VV) using computerized microtomography (μCT) in bulk fill resin composites and conventional class I restorations, and to establish a correlation between these factors. Class I cavities (4 x 5 x 4 mm), C-factor = 4.2, were performed on caries-free human third molars and randomly divided into five groups (n = 6): FSI (Filtek Supreme XTE incremental insertion); FSS [(Filtek Supreme XTE single insertion(SI)]; TBF [(Tetric Bulk Fill: SI and manual filling (MF)]; SFM (Sonic Fill: SI/MF); and SFS (SonicFill: SI and sonic filling). The teeth were scanned and analyzed by μCT at T0, after filling the cavity with resin, and at T1, after polymerization for VG and VV, and for VS (T1-T0). There was statistically significant difference in VS in μCT for the FSI and FSS groups and between SFS and FSS as well as some difference in VV for FSI and bulk fill resin composites and no difference in VG between the conventional technique and bulk fill composites. Bulk fill resin composites presented similar VS and gap formation to those of incrementally inserted conventional resin composites. There is a moderate and weak positive correlation between polymerization shrinkage and gap formation and void, respectively. The final gap formation was more dependent on the initial gap than on polymerization shrinkage or void volume.

Radiopacity of Methacrylate and Silorane Composite Resins Using a Digital Radiographic System.

The aim of this study was to evaluate the radiopacity of silorane and methacrylate resin composites, comparing them to the enamel, dentin, and aluminum penetrometer using a digital image. From six resin composites (Filtek™ P90, Filtek Z350, Filtek Z350 XT flow, Tetric Ceram, TPH Spectrum, and SureFil SDR flow) cylindrical disks (5 × 1 mm) were made and radiographed by a digital method, together with a 15-step aluminum step-wedge and a 1 mm slice of human tooth. The degree of radiopacity of each image was quantified using digital image processing. The mean values of the shades of gray of the tested materials were measured and the equivalent width of aluminum was calculated for each resin. The results of our work yielded the following radiopacity values, given here in descending order: Tetric Ceram > TPH > SDR > Z350 > Z350 flow > P90 > enamel > dentin. The radiopacity of the materials was different both for the enamel and for the dentin, except for resin P90, which was no different than enamel. In conclusion, silorane-based resin exhibited a radiopacity higher than dentin and closest to the enamel; a large portion of the methacrylate-based flow and conventional resins demonstrated greater radiopacity in comparison to dentin and enamel.

Nd:YAG laser influence on the hybridization quality, employing total-etching or self-etching adhesives: sem analysis / Influência do laser de Nd:YAG na qualidade de hibridização empregando-se sistemas adesivos de condicionamento total ou autocondicionante: análise em MEV

A aplicação do laser de Nd:YAG na dentina sobre o sistema adesivo não polimerizado pode influenciar a qualidade da camada híbrida formada. Objetivo: o objetivo deste estudo foi verificar através da análise em microscopia eletrônica de varredura (MEV) a influência do laser de Nd:YAG na qualidade de hibridização, usando-se o sistema adesivo de condicionamento total Adper Single Bond 2 (SB) ou o auto-condicionante Clearfil SE Bond(CSEB). Material e Métodos: nove incisivos foram seccionados resultando em 36 espécimens que foram divididos em 2 grupos (n=18): Group SB- adesivo de condicionamento total SB; Group CSEB-adesivo auto-condicionante CSEB. Previamente à aplicação dos sistemas adesivos, cada grupo foi dividido em 3 subgrupos de acordo com os parâmetros do laser de Nd:YAG (n=6): Subgroup controle- polimerização do adesivo por 10s (600 mW/cm2); Subgrupo Laser 60 mJ: laser de Nd:YAG (60 mJ, 10Hz, 74,72 J/cm2) com irradiação sobre a dentina impregnada com sistema adesivo não polimerizado + polimerização por 10s (600 mW/cm2); Subgrupo Laser 140 mJ: laser de Nd:YAG (140 mJ, 10Hz, 174,34 J/cm2)com irradiação sobre a dentina impregnada com sistema adesivo não polimerizado + polimerização por 10s (600 mW/cm2). Todos os espécimens foram restaurados com resina composta (Filtek Z350 - 3M). A espessura, a presença de falhas (fendas/ porosidades) e características dos tags/microtags na camada híbrida foram analisados em MEV. Os resultados foram submetidos aos testes estatísticos

Background: The application of Nd:YAG laser on dentin with the non polymerized adhesive can influenced the quality of hybrid layer formed. Objectives: The aim of this study was to assess through analysis by scanning electronic microscopy (SEM), the Nd:YAG laser influence on the hybridization quality, using totaletching Single Bond (SB) or self-etching Clearfil SE Bond (CSEB) adhesives. Material and Methods: Nine bovine incisors were sectioned and resulted in 36 specimens and divided into 2 groups (n=18): Group SB – SB total-etching adhesive; Group CSEB - CSEB selfetching adhesive. Before the polymerization of these adhesives, each group was divided in 3 subgroups, according to the laser parameters (n=6): Subgroup Control - polymerization for 10 s (600 mW/cm2);Subgroup Laser 60mJ: Nd:YAG laser (60mJ, 10Hz, 74.72J/cm2) irradiation on dentin impregnated with non polymerized adhesives + polymerization for 10 s (600 mW/cm2); Subgroup Laser 140mJ - Nd:YAG laser (140mJ, 10Hz, 174.34J /cm2) irradiation ondentin impregnated with non polymerized adhesives + polymerization for 10s (600 mW/cm2)....

Aspectos odontológicos a serem considerados para o tratamento de portadores da doença de Alzheimer / Dental issues to be considered on the treatment of patients with AlzheimerÆs disease

A doença de Alzheimer é uma doença neurodegenerativa que provoca o declínio das funções intelectuais, reduzindo as capacidades de trabalho e relação social, interferindo no comportamento e personalidade do indivíduo. O objetivo deste estudo foi analisar os aspectos relativos às necessidades odontológicas dos pacientes idosos portadores de Alzheimer. Para tanto, foi realizada uma revisão de literatura utilizando as bases de dados, em que os resultados foram divididos em dois tópicos: considerações relativas ao tratamento odontológico e alterações bucais frequentes em pacientes com doença de Alzheimer. Concluiu-se que o cirurgião dentista deve conhecer as características dos pacientes com doença de Alzheimer planejando o tratamento mais adequado, e orientando a equipe de saúde, cuidadores e familiares a fim de ser obter sucesso na implementação de medidas preventivas e curativas...

Alzheimer disease is a neurodegenerative disease that causes the decline of intellectual functions, reducing the capacity for work and social relationships, interfering with the behavior and personality of the individual. The aim of this study was to analyze factors related to dental needs of elderly patients with AlzheimerÆs. Therefore, it was conducted a literature review and the results were divided into two topics: considerations about dental treatment and frequent buccal alterations in patients with AlzheimerÆs. It was concluded that it is important that the dentist knows the characteristics of patients with degenerative diseases in order to develop proper treatment planning, and guide caregivers and family in order to achieve successful adoption of preventive and healing measures...

In vivo Evaluation of Proximal Resin Composite Restorations performed using Three Different Matrix Systems.

OBJECTIVE: The aim of this in vivo study was to radiographically evaluate the proximal contour of composite resin restorations performed using different matrix systems. MATERIALS AND METHODS: Patients with premolars needing class II type resin composite restorations involving the marginal ridge were selected. Thirty premolars were selected and randomly divided into three groups (n = 10 each) to receive restorations using different matrix systems: group 1: metal matrix coupled to a carrier matrix and wood wedge (G1-MMW); group 2: sectioned and precontoured metal matrix and elastic wedge (G2-SME); and group 3: a polyester strip and reflective wedge (G3-PMR). After the restorative procedure, bitewing radiographs were performed and analyzed by three calibrated professionals. The quality of the proximal contact and marginal adaptation of the proximal surfaces was classified as either correct or incorrect (undercontour/overcontour). RESULTS: The Pearson Chi-square statistical test (α = 5%) revealed a statistically difference between frequencies of correct and incorrect restorations (α(2) = 6.787, p < 0.05). The group G2 SME produced a higher frequency of correct proximal contours (90%), while G1-MMW and G3-PMR had a ratio of 40% correct and 60% incorrect contours respectively. CONCLUSION: None of the matrix systems was able to prevent the formation of incorrect proximal contours; however, the sectioned and precontoured metal matrix/elastic wedge configuration provided better results as compared to the other groups.

Shear Bond Strength of Orthodontic Brackets Fixed with Remineralizing Adhesive Systems after Simulating One Year of Orthodontic Treatment.

The objective of this study is to assess, in vitro, the shear bond strength of orthodontic brackets fixed with remineralizing adhesive systems submitted to thermomechanical cycling, simulating one year of orthodontic treatment. Sixty-four bovine incisor teeth were randomly divided into 4 experimental groups (n = 16): XT: Transbond XT, QC: Quick Cure, OL: Ortholite Color, and SEP: Transbond Plus Self-Etching Primer. The samples were submitted to thermomechanical cycling simulating one year of orthodontic treatment. Shear bond strength tests were carried out using a universal testing machine with a load cell of 50 KgF at 0.5 mm/minute. The samples were examined with a stereomicroscope and a scanning electron microscope (SEM) in order to analyze enamel surface and Adhesive Remnant Index (ARI). Kruskal-Wallis and Mann-Whitney (with Bonferroni correction) tests showed a significant difference between the studied groups (p < 0.05). Groups XT, QC, and SEP presented the highest values of adhesive resistance and no statistical differences were found between them. The highest frequency of failures between enamel and adhesive was observed in groups XT, QC, and OL. Quick Cure (QC) remineralizing adhesive system presented average adhesive resistance values similar to conventional (XT) and self-etching (SEP) adhesives, while remineralizing system (OL) provided the lowest values of adhesive resistance.

Effect of Fluoride and Simplified Adhesive Systems on the Bond Strength of Primary Molars and Incisors.

The aim of this study was evaluate in vitro the influence of simplified adhesive systems (etch-and-rinse and self-etching) and 1.23% acidulated phosphate fluoride (APF) on the microshear bond strength (µ-SBS) of composite resins on primary molars and incisors. Forty primary molars and forty incisors vestibular enamel was treated with either the self-etching Clearfil SE Bond (CSE, Kuraray) or etch-and-rinse Adper Single Bond 2 (SB2, 3M/ESPE) adhesive system. Each group was subdivided based on the prior treatment of the enamel with or without the topical application of 1.23% APF. Thereafter, matrices were positioned and filled with composite resin and light cured. After storage in distilled water at 37 ± 1°C for 24 h, the specimens were submitted to µ-SBS in a universal testing machine. Kruskal-Wallis and Mann-Whitney tests (p < 0.05) showed that the prior application of 1.23% APF led to a significant reduction in bond strength. The type of adhesive exerted no significant influence bond strength. In the inter-group analysis, however, significantly bond strength reduction was found for the incisors when CSE was employed with APF. Adhesive failure was the most common type of fracture. The bond strength was affected by the prior application of 1.23% APF and type of tooth.