Longitudinal bond strength of a universal adhesive and chemical dentin characterization under different acid etching protocols.

OBJECTIVE: This study aimed to analyze the longitudinal bond strength of a universal adhesive and chemically characterize the dentin substrate under different acid etching protocols. METHODOLOGY: Dentin samples were etched with polyacrylic acid 25% (PAA) for 10 seconds (n=3) and phosphoric acid 32% (PA) for 15 seconds (n=3) and analyzed by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) before and after treatment. For collagen degradation, samples (n=12) were divided into 3 groups: PAA, PA, and Deionized water (control), and analyzed by the quantity of solubilized type I collagen C-terminal cross-linked telopeptides and solubilized C-terminal peptide in relation to total protein concentration (ICTPtp and CTXtp) and by their ultimate tensile strength (UTS). For the adhesive interface analysis, dentin samples (n=72) were divided into 3 groups: PAA, PA, and Self-etch (SE), and subdivided into 2 groups: 24 h (baseline) and 1 year. The following tests were performed: microtensile bond strength (µTBS) (n=48), scanning electron microscopy (SEM) (n=12), and nanoleakage (n=12). RESULTS: The FTIR of PAA showed lower reduction of the peaks in the phosphate group when compared to PA. For ICTPtp, PA showed a significantly higher value. For CTXtp, PA and PAA groups failed to statically differ from each other. UTS was significantly lower for PA. For µTBS, storage time significantly affected bond strength. The results were unaffected by the etching protocol. For SEM, after 1 year, PA had little evidence of degradation in the upper third of the adhesive interface in comparison to the other groups. Nanoleakage showed no considerable silver impregnation after 1 year in the SE group. CONCLUSION: The use of PAA prior to a universal adhesive (when compared to PA) represents a less aggressive type of etching to dentin. However, self-etching still seems to be the best option for universal adhesive systems that have functional monomers in their composition.

Longitudinal bond strength of a universal adhesive and chemical dentin characterization under different acid etching protocols

Abstract Objective This study aimed to analyze the longitudinal bond strength of a universal adhesive and chemically characterize the dentin substrate under different acid etching protocols. Methodology Dentin samples were etched with polyacrylic acid 25% (PAA) for 10 seconds (n=3) and phosphoric acid 32% (PA) for 15 seconds (n=3) and analyzed by Fourier transform infrared spectroscopy - attenuated total reflectance (FTIR-ATR) before and after treatment. For collagen degradation, samples (n=12) were divided into 3 groups: PAA, PA, and Deionized water (control), and analyzed by the quantity of solubilized type I collagen C-terminal cross-linked telopeptides and solubilized C-terminal peptide in relation to total protein concentration (ICTPtp and CTXtp) and by their ultimate tensile strength (UTS). For the adhesive interface analysis, dentin samples (n=72) were divided into 3 groups: PAA, PA, and Self-etch (SE), and subdivided into 2 groups: 24 h (baseline) and 1 year. The following tests were performed: microtensile bond strength (μTBS) (n=48), scanning electron microscopy (SEM) (n=12), and nanoleakage (n=12). Results The FTIR of PAA showed lower reduction of the peaks in the phosphate group when compared to PA. For ICTPtp, PA showed a significantly higher value. For CTXtp, PA and PAA groups failed to statically differ from each other. UTS was significantly lower for PA. For μTBS, storage time significantly affected bond strength. The results were unaffected by the etching protocol. For SEM, after 1 year, PA had little evidence of degradation in the upper third of the adhesive interface in comparison to the other groups. Nanoleakage showed no considerable silver impregnation after 1 year in the SE group. Conclusion The use of PAA prior to a universal adhesive (when compared to PA) represents a less aggressive type of etching to dentin. However, self-etching still seems to be the best option for universal adhesive systems that have functional monomers in their composition.

Insights on the role of cytokines in carious lesions / Insights sobre o papel das citocinas em lesões cariosas

Objetivo: A resposta imune da dentina-polpa à patogênese da cárie ainda é pouco compreendida devido à complexa interação dos processos envolvidos. O objetivo desta revisão foi explorar o papel das citocinas e sua relevância na patogênese da cárie dental. Resultados: A cárie dentária pode resultar em uma resposta inflamatória do hospedeiro na polpa dental, caracterizada pelo acúmulo de células inflamatórias levando à liberação de citocinas inflamatórias como, Interleucina-4 (IL-4), Interleucina (IL-6), Interleucina-8 (IL-8) e fator de necrose tumoral­α(TNF-α). IL-4 parece estar correlacionada com a profundidade das lesões cariosas; IL-6 está fortemente correlacionada com a doença cárie e é considerada um potente biomarcador; IL-8 pode ser um potente biomarcador tanto para cárie quanto para outras alterações presentes na polpa e sua liberação está correlacionada com TNF-α e IL-6; TNF-α desempenha um papel importante não apenas na progressão da cárie, mas também em outros processos patológicos. Conclusao: Mediadores específicos têm um grande potencial para servir como biomarcadores quanto à presença e progressão da doença cárie, o que incita a necessidade de mais investigações nesse campo (AU).

Objectives: The dentin-pulp immune response to caries pathogenesis is still poorly understood due to the complex interplay of the involving processes. The aim of this review was to explore the role of cytokines and its relevance in the pathogenesis of dental caries. Results: Dental caries can result in a host inflammatory response in the dental pulp, characterized by the accumulation of inflammatory cells leading to the release of inflammatory cytokines such as Interleukin-4 (IL-4), Interleukin (IL-6), Interleukin-8 (IL-8) and Tumor necrosis factor­ α (TNF- α ). IL-4 seems to be correlated to the depth of carious lesions; IL-6 is strongly correlated to caries disease and is considered a potent biomarker; IL-8 can be a potent biomarker for both caries and other changes present in the pulp and, its release is correlated to TNF- α and IL-6; TNF-α plays an important role not only in caries progression, but also in other pathological processes. Conclusion: Specific mediators have a great potential to serve as biomarkers alluding to the presence and progress of caries disease, urging further investigations in the field (AU)

Effect of fluoride, chlorhexidine or Nd:YAG on the progression of root dentin demineralization after removal of the demineralized organic matrix.

OBJECTIVES: Quantification of collagen degradation is an important parameter to evaluate dentin caries for preventive aid.. Evaluate preventive methods against root collagen degradation by the hydroxyproline assay (HYP) and microradiography technique (MRT). METHODOLOGY: Five bovine root dentin blocks were obtained and subjected to an artificial demineralization process by acetate buffer (pH 5) to induce carious lesion formation. Samples were subjected to the following therapeutic treatments: 1) 0.12% chlorhexidine for 1 min, 2) 2% fluoride for 1 min, 3) Nd:YAG Laser (400 µm diameter optical fiber, 10 Hz frequency, 60 mJ/pulse energy, 48 J/cm2 energy density, in noncontact mode for 10 s), 4) deionized water (control) for 1 min, 5) MRT control group (without treatment and removal of collagen). Samples were exposed to degradation by a collagenase enzyme for five days. The enzyme solution was collected, by colorimetry in a spectrophotometer, from the collagen matrix for the hydroxyproline release analysis. The same samples were subjected to an additional two days of demineralization to induce the progression of mineral loss. Samples were analyzed by MRT for the visualization of their degraded areas (estimation of lesion depth and mineral loss). ANOVA was applied to compare hydroxyproline release rates. MRT data were subjected to the Kruskal-Wallis test, followed by the Dunn's test. Comparisons between the initial five-day and the subsequent two-day demineralization processes were performed by repeated t-test or Wilcoxon (p<0.05) measurements. RESULTS: The amount of HYP released from the dentin samples failed to show significant differences among the groups (p=0.09). Fluoride and chlorhexidine were able to interact with the samples, reducing the progression of dentin caries after removal of the demineralized organic matrix. CHX was the only treatment able to show significant lower lesion depth than the negative control. CONCLUSION: Chlorhexidine and fluoride were effective in reducing root caries progression.

Universal adhesive: the effect of different simulated pulpal pressure fluids and bonding modes to dentin.

The aim of this study was to evaluate the effect of SPP with either fetal bovine serum (FBS) or deionized water (DW) on the bond strength (µTBS) of a Universal adhesive to dentin, in both etch-and-rinse (ER) and self-etch (SE) modes. The kinematic viscosity (cSt) of FBS and DW was measured at 25 °C ± 0.1 ºC. Seventy-two sound human molars were sectioned and randomly divided into three groups according to the SPP conditions: (1) Control (0 cm H2O), (2) SPP (15 cm H2O) with FBS, (3) SPP (15 cm H2O) with DW. Each group was subdivided (n = 10) based on the bonding modes: ER (37% phosphoric acid + ScothBond Universal Adhesive) or SE (ScothBond Universal Adhesive). Samples were then submitted to µTBS. Data were analyzed by Student's t test, two-way ANOVA and Tukey tests (p < 0.05). The cSt results showed that DW (23.59 ± 0.39) had significantly higher values than FBS (22.33 ± 0.06). With regard to SPP, the control group (36.1 MPa) had significantly higher values of µTBS when compared to the SPP using FBS (31.06 MPa) and SPP with DW (26.55 MPa). According to ANOVA, the bonding modes and the interaction of simulated pulpal pressure (SPP) did not statistically influence the results (p < 0.05). The presence of SPP reduced the bond strength of Universal adhesive to dentin. DW during SPP had significantly reduced bonding values when compared to FBS. Bonding strategies were not affected by SPP when evaluated in a short period of time (24 h).

Effect of fluoride, chlorhexidine or Nd:YAG on the progression of root dentin demineralization after removal of the demineralized organic matrix

Abstract Quantification of collagen degradation is an important parameter to evaluate dentin caries for preventive aid. Objectives: Evaluate preventive methods against root collagen degradation by the hydroxyproline assay (HYP) and microradiography technique (MRT). Methodology: Five bovine root dentin blocks were obtained and subjected to an artificial demineralization process by acetate buffer (pH 5) to induce carious lesion formation. Samples were subjected to the following therapeutic treatments: 1) 0.12% chlorhexidine for 1 min, 2) 2% fluoride for 1 min, 3) Nd:YAG Laser (400 μm diameter optical fiber, 10 Hz frequency, 60 mJ/pulse energy, 48 J/cm2 energy density, in noncontact mode for 10 s), 4) deionized water (control) for 1 min, 5) MRT control group (without treatment and removal of collagen). Samples were exposed to degradation by a collagenase enzyme for five days. The enzyme solution was collected, by colorimetry in a spectrophotometer, from the collagen matrix for the hydroxyproline release analysis. The same samples were subjected to an additional two days of demineralization to induce the progression of mineral loss. Samples were analyzed by MRT for the visualization of their degraded areas (estimation of lesion depth and mineral loss). ANOVA was applied to compare hydroxyproline release rates. MRT data were subjected to the Kruskal-Wallis test, followed by the Dunn's test. Comparisons between the initial five-day and the subsequent two-day demineralization processes were performed by repeated t-test or Wilcoxon (p<0.05) measurements. Results: The amount of HYP released from the dentin samples failed to show significant differences among the groups (p=0.09). Fluoride and chlorhexidine were able to interact with the samples, reducing the progression of dentin caries after removal of the demineralized organic matrix. CHX was the only treatment able to show significant lower lesion depth than the negative control. Conclusion: Chlorhexidine and fluoride were effective in reducing root caries progression.

Interaction of epigallocatechin-gallate and chlorhexidine with Streptococcus mutans stimulated odontoblast-like cells: Cytotoxicity, Interleukin-1ß and co-species proteomic analyses.

OBJECTIVES: The dentin therapeutic agent chlorhexidine has inflammatory and cytotoxic characteristics urging investigation of alternatives like the natural compound epigallocatechin-gallate. The aim is to verify the effect of epigallocatechin-gallate and chlorhexidine on viability, interleukin-1ß (IL-1ß) and differential protein expression of MDPC-23 odontoblast-like cells stimulated by Streptococcus mutans. DESIGN: Cells were stimulated with heat-killed S. mutans at multiplicity of infection (MOI) of 100-1000 and subsequently treated with 100-1 µM of epigallocatechin-gallate. Cells with no treatment or chlorhexidine were controls. Combined stimulated/treated cells were tested for cytotoxicity (Alamar-Blue, N = 3, n = 3), total protein (N = 3, n = 3), IL-1ß (ELISA, N = 3, n = 3), and differential protein expression by liquid chromatography-tandem mass spectrometry (LC-MS/MS, n = 2). RESULTS: Cells stimulated at MOI 100/1000 and treated with 10 µM epigallocatechin-gallate and chlorhexidine did not present cytotoxicity. IL-1ß significantly increased in both un-stimulated and stimulated chlorhexidine 10 µM groups when compared to un-treated control (p < 0.05). MOI 100 chlorhexidine 10 µM group significantly increased IL-1ß compared to un-stimulated chlorhexidine 10 µM and epigallocatechin-gallate 10 µM groups, as well as to MOI 100 epigallocatechin-gallate 10 µM group (p < 0.05). LC-MS/MS revealed S. mutans and mammalian proteins, with tooth-specific proteins exhibiting different abundance levels, depending on the tested condition. CONCLUSIONS: Odontoblast-like cells stimulated with S. mutans at different MOI combined with epigallocatechin-gallate treatment did not cause cytotoxicity. S. mutans stimulation combined with chlorhexidine 100 µM treatment decreased cell viability, while treatment with chlorhexidine 10 µM concentration significantly increased IL-1ß. S. mutans stimulation and treatment of cells resulted in varied protein expression.

A 2-year clinical evaluation of direct and semi-direct resin composite restorations in non-carious cervical lesions: a randomized clinical study.

OBJECTIVES: The purpose of this study was to evaluate the 2-year success of resin composite restorations in non-carious cervical lesions (NCCLs) using the direct or semi-direct techniques. MATERIALS AND METHODS: Thirty volunteers presenting with at least two NCCLs were included. Each participant received one restoration using the direct technique and the other using the semi-direct technique, totaling 60 restorations. Time for completing the treatment was computed. Assessments at baseline, 7 days, and 6, 12, and 24 months were performed using the modified United States Public Health Service criteria. Descriptive analysis was reported as a percentage of successful treatments. For inferential analysis, the Student t test was used to evaluate the differences between extension, depth, and time. The chi-square/Fisher tests were used to compare treatment success after each period (α = 0.05). The results were evaluated by using the Kaplan-Meier survival analysis. RESULTS: Differences were detected regarding mean ± standard deviation time, in which direct and semi-direct procedures were accomplished in 21.8 (± 14.5) and 35.3 (± 19.9) min, respectively. Of the 60 restorations placed, 7 failed in the direct group while 8 failed in the semi-direct group up to 2 years. No differences were detected between restorative protocols. The cumulative survival was 88.5% and 88.4% for the direct technique and semi-direct techniques after 24 months, respectively. CONCLUSION: The tested restorative protocols present similar results for NCCLs within the studied periods. CLINICAL RELEVANCE: The semi-direct technique exhibited clinical performance similar to direct technique for NCCL, demonstrating an alternative for restorations of these lesions.

Analysis of adhesive bond strength under simulated pulpal pressure during laser irradiation on different dentin thicknesses / Análise da resistência adesiva sob pressão pulpar simulada durante irradiação laser em diferentes espessuras de dentina

Objective: Evaluate the microtensile bond strength (µTBS) in different dentin thicknesses, under simulated pulpal pressure (SPP), submitted to an adhesive technique using laser irradiation. Material and methods: Forty sound human molars were sectioned and randomly divided into two groups (n=20): Group 1 ­ 1 mm of dentin thickness; Group 2 ­ 2 mm of dentin thickness. Each group was divided into two subgroups (n=10): Subgroup A ­ Absence of SPP; Subgroup P ­ Presence of SPP (15 cm H2 O). The samples were sequentially treated with: 37% phosphoric acid, adhesive system (Adper Single Bond 2), Nd:YAG laser irradiation (60 s, 1064 nm, 10 Hz) using 60 and 100 mJ/pulse energy parameters and photopolymerization (10 s). A composite resin block (Filtek Z350) was built up onto the irradiated area. After 30 days stored in water, the samples were sectioned and submitted to microtensile test (10 kgf load cell, 0.5mm/min). Data were analyzed by twoway ANOVA and Tukey tests. Results: Two-way ANOVA revealed no significant differences for SPP on bond strength. The laser energy parameters indicated that 100 mJ showed greater µTBS means compared to the group irradiated with 60 mJ. The presence of SPP reduced the mean µTBS values. Conclusions: Simulated pulpal pressure did not affect the µTBS using 60 mJ of laser energy parameter. At 100 mJ, the presence of SPP negatively influenced the bond strength, regardless of dentin thickness (AU)

Objetivo: O objetivo deste estudo foi avaliar a resistência adesiva (RA) em diferentes espessuras de dentina, associada à pressão pulpar simulada (PPS), quando submetidos à técnica adesiva por irradiação laser. Material e Métodos: Quarenta molares humanos hígidos foram seccionados e divididos aleatoriamente em dois grupos (n=20): Grupo 1 ­ 1 mm de espessura de dentina; Grupo 2 ­ 2 mm de espessura de dentina. As amostras foram divididas em 2 subgrupos (n=10): Subgrupo A ­ ausência de PPS; Subgrupo P ­ presença de PPS (15 cm de H2 O). As amostras foram tratadas seqüencialmente com: ácido fosfórico 37%, sistema adesivo (Adper Single Bond 2), irradiação com Nd:YAG laser (60 s, 1064 nm, 10 Hz) nos parâmetros de energia de 60 e 100 mJ/pulso e fotopolimerização (10 s). Um bloco de resina composta (Filtek Z350, 3M ESPE) foi confeccionado sobre a área irradiada. Após 30 dias armazenados em água, os espécimes foram seccionados e submetidos ao teste de microtração (carga de 10 kgf, 0.5mm/min). Os dados foram analisados pelos testes ANOVA sob 2 fatores e Tukey (p<0.05). Resultados: ANOVA mostrou que não houve diferenças significativas para PPS na RA. Para os parâmetros de energia do laser, 100 mJ apresentou maiores médias de RA quando comparado ao grupo irradiado à 60 mJ. A presença da PPS reduziu as médias de RA. Conclusão: Pressão pulpar simulada não afetou os valores de resistência adesiva para o grupo irradiado com 60 mJ. Para 100 mJ, a presença da pressão pulpar influenciou negativamente na resistência adesiva, independente das espessuras de dentina.(AU)

Functionalized epigallocatechin gallate copolymer inhibit dentin matrices degradation: Mechanical, solubilized telopeptide and proteomic assays.

OBJECTIVES: We investigated the biostability of dentin organic matrices treated with epigallocatechin gallate (EGCG) in comparison to chlorhexidine (CHX), both extracted from functionalized copolymers. METHODS: Copolymers were prepared with bis-GMA:TEGDMA and incorporated with 1% of EGCG or CHX (w/w). Blank copolymers were used as control. Copolymer samples were individually stored in 1mL deionized water to produce copolymer extracts. Dentin matrices were obtained by demineralization of dentin disks in 10% phosphoric acid solution. Matrices were individually treated with 1mL of the copolymer extracts or distilled water for 48h. Collected extracts were analyzed by high-performance liquid chromatography (HPLC) for the presence and quantification of EGCG, CHX, and copolymer by-products. Treated dentin matrices were tested for ultimate tensile strength, gravimetric changes, and swelling ratio. The treatment media were tested for total protein concentration, and dentin protease activity through solubilized telopeptide (ICTP- and CTX-ELISA) assays. The treatment media were also submitted to proteomic analysis. RESULTS: HPLC identified released unreacted copolymer species and showed higher release of CHX compared to EGCG from respective copolymer extracts. EGCG extract inhibited activity of dentin proteolytic enzymes and promoted collagen biomodification observed by the telopeptide assays and in the changes to dentin matrix properties. The proteomic results showed less collagenous peptide hits in the EGCG extract media compared to CHX, and suggest compound-specific dentin protein binding interactions. SIGNIFICANCE: This study demonstrates specific antiproteolytic effect and protein interactions of EGCG copolymer extract directly on dentin. This represents an advancement in dental materials which can impact the clinical procedures.

Sistema adesivo universal: análise da interface adesiva e degradação colagenolítica em dentina submetida à diferentes protocolos de condicionamento ácido / Universal adhesive system: analysis of adhesive interface and collagenolytic degradation of demineralized dentin submitted to different acid etching ptotocols

O objetivo desse estudo foi analisar a interface adesiva do sistema adesivo Single Bond Universal (SBU) em dentina submetida à diferentes protocolos de condicionamento ácido em 24 h e 12 meses. E a degradação colagenolítica (DC) mediada por metaloproteinases (MMPs) e Catepsina-K (CAT-K) em tempo imediato. Esse estudo foi conduzido em 3 etapas: 1) Caracterização química da dentina em FTIR; 2) DC por meio de fragmentos do Telelopeptídeo Carboxiterminal do Colágeno Tipo I (ICTP) e do Terminal C do Telopeptídeo ligado ao Colágeno Tipo I (CTX) e a resistência à tração (RT) da do colágeno; 3) Análise da interface adesiva através da resistência de união (RU), análise de fratura, microscopia eletrônica de varredura (MEV) e nanoinfiltração (NI). Para FTIR foram utilizados 6 discos de dentina, divididos em 2 grupos: 1) Ácido fosfórico 32 %15 s (AF), 2) Ácido poliacrílico 25 % 10 s (AP). Para análise da DC, 12 discos de dentina foram completamente desmineralizados e divididos em 3 grupos: 1) AF, 2) AP e 3) Água deionizada (Controle) 15 s. Após, foram incubados e armazenados por 1 semana. Seguindo-se a análise da concentração de proteína total (PT). 50 µl da solução de incubação foram utilizadas para analisar ICTP e CTX. As concentrações foram calculadas em relação à PT. Para RT, foram testados 36 palitos obtidos dos discos de colágeno. Para RU foram utilizados 48 dentes, divididos em 2 grupos, de acordo com o período de armazenamento, divididos em três subgrupos: 1) AF, 2) AP e 3) Autocondicionante SBU 20 s (SE). Os dentes foram restaurados e armazenados em água destilada 37 °C. Após, foram submetidos ao teste de microtração e análise de fraturas. Para as análises MEV e NI foram utilizados 2 espécimes de cada subgrupo. Para análise estatística utilizou-se ANOVA 1-Fator, ANOVA- 2 Fatores e teste de Tukey (α=0.05). Para FTIR, AF reduziu a quantidade de fosfato e carbonato quando comparado ao AP. Para DC, a liberação de ICTPPT para AF foi significantemente maior do que para AP (p < 0,05). Não houve diferença na liberação de CTXPT para AF e AP (p > 0,05). Para RT não houve diferença entre AP e Controle, porém, apresentaram valores maiores do que AF (p<0,05). Para RU em MPa, não houve diferença estatisticamente significativa para todos os tratamentos nos diferentes períodos de análise (p < 0,05). A análise de fraturas evidenciou a predominância de fraturas adesivas e mistas. MEV mostrou melhor qualidade da interface após 12 meses para AF e AP. Após 12 meses apenas SE não apresentou NI. Assim sendo, o autocondicionamento ainda parece ser a melhor opção para sistemas adesivos universais que possuam monômeros funcionais em sua composição.(AU)

The aim of this study was to analyze the adhesive interface of the Single Bond Universal (SBU) to dentin submitted to different acid etching protocols in 24 h and 12 months, and the collagenolytic degradation (CD) by matrix metalloproteinases (MMPs) and Cathepsin-K (CAT-K) in the immediate time. This study was divided into three stages: 1) Dentin chemical characterization by FTIR; 2) CD by release of the collagen telopeptide fragment cross-linked carboxyterminal telopeptide of type I collagen (ICTP), and C-terminal crosslinked telopeptide of type I collagen (CTX) and ultimate tensile strength (UTS); 3) Analysis of the adhesive interface by microtensile bond strength (µTBS), failure mode, scanning electron microscopy (SEM) of the AI, and nanoleakage by SEM (NL). For FTIR, six dentin disks were divided into two groups: 1) Phosphoric acid 15 s (PA), 2) Polyacrylic acid 10 s (PAA). For CD twelve dentin disks were completely demineralized, then were divided into 3 groups 1) PA, 2) PAA, and 3) deionized water (Control) for 15 s. All disks were incubated in a buffered solution (BS) for 1 week. Total protein (TP) concentrations were measured using Nanodrop™ at 280 nm. 50 µl of BS was used to analyze solubilized telopeptide fragments using ICTP and CTX . ICTP and CTX average ratios were calculated in relation to TP concentration (ICTPtp and CTXtp). For UTS, 36 dentin beams obtained from collagen disks were tested. For µTBS, forty-eight teeth were divided into two groups according to the period of storage, then subdivided into three subgroups: 1) PA, 2) PAA, and 3) Self-etch 20 s (SE). After, composite build up, the specimens were stored in distilled water at 37 °C. Two specimens of each group were used for SEM analysis of AI and NL. Data were analyzed by one-way ANOVA, two-way ANOVA and Tukey tests (p<0.05). According to the results of the FTIR etching with PA reduced the amount of phosphate and carbonate when compared to PAA. ICTPtp release of PA was significantly higher A than PAA (p > 0,05). CTXtp showed no difference between the PA and PAA (p < 0,05). For UTS there was no difference between PAA and control, but they were significantly higher (p<0.05) than PA. For µTBS in MPa, there is no statistical difference among all the etching protocols tested, as well in both storage periods of analysis (p < 0,05). The most prevalent failure mode were adhesives associated with mixed. SEM analysis highlighted a better quality of AI after 12 months for PA and PAA. However, after 12 months only SE did not show NL. Then, the self-etching protocol seems to be a better choice regarding universal adhesive systems which have functional monomers in their blend(AU)

Staining Beverages and Cigarette Smoke on Composite Resin and Human Tooth Fluorescence by Direct Spectrometry.

INTRODUCTION: This study evaluated the fluorescence intensity (FI) of different brands of composite resins (CRs) and compare those values with the FI of human tooth, under the action of cigarette smoke (CI), coffee (CA), and soft drink (CO), measured by direct spectrometry. MATERIALS AND METHODS: A total of 30 specimens of each brand (Filtek Z350, Esthet-X, Amelogen, Durafill) were made. Others 30 tooth specimens (3 mm/diameter) were obtained from human molars using a trephine bur. The specimens were randomly divided into three groups (n = 10), according to substances: CI, CA, CO. The FI was directly measured using an optic fiber associated with a spectrometer and was measured at baseline and after staining. Data were submitted to Kruskal-Wallis, Dunnett, and Dunn tests. RESULTS: Staining influenced FI mean values among CRs and between those with human tooth. Z showed the closest FI mean values of tooth after staining. CONCLUSION: Staining beverages and cigarette smoke negatively influenced on FI of CR and human tooth. CLINICAL SIGNIFICANCE: The study shows darkening treatments influenced on the fluorescent property of the dental tissues and restorative materials according to the direct spectrometry analysis.

Influence of simulated pulpal pressure on the variation of intrapulpal temperature during adhesive system light-curing / Influência da pressão pulpar simulada na variação de temperatura intrapulpar durante a fotopolimerização do sistema adesivo

Objective: To evaluate the effects of simulated pulpal pressure (SPP) on the variation of intrapulpal temperature (T) during lightcuring of the adhesive system. Material and Methods: One hundred sound human molars were sectioned from the highest pulp horn to obtain a 2-mm of thickness dentin. The specimens were randomly divided into two groups: (n = 50), according to the presence or absence of SPP (15 cm H2 O). The specimens were sequentially treated as follows: 37% phosphoric acid (Scotchbond Universal; 3M/ESPE), adhesive system (Scotchbond Universal/3M ESPE) and light-curing (10 s). T was evaluated during adhesive lightcuring with a K-type thermometer put inside the pulp chamber. Data were analysed by using Mann-Whitney's test (at 5%). Results: According to Mann-Whitney's test, the absence group presented a T of 2 °C, whereas the presence group 1 °C. The mean values of T were 0.82 ± 0.56 °C for the presence group and 2.30±0.73 °C for the absence group. Conclusion: Simulated pulpal pressure significantly reduced the temperature rise in the pulp chamber during light-curing of the adhesive system, showing the importance of inserting this protocol of simulated pulpal pressure in the laboratory procedures.(AU)

Objetivos: Avaliar os efeitos da pressão pulpar simulada (PPS) na variação de temperatura (DT) durante a fotopolimerização do sistema adesivo. Material e Método: Cem molares humanos hígidos foram seccionados para obtenção de 2 mm de espessura de dentina, a partir do corno pulpar mais alto. As amostras foram divididas aleatoriamente em 2 grupos (n = 50): ausência e presença de PPS (15 cm de H2 O). As amostras foram tratadas seqüencialmente com: ácido fosfórico 37% (Scotchbond Universal; 3M/ESPE), sistema adesivo (Scotchbond Universal/3M ESPE), seguida da fotopolimerização (10 s). Na seqüência, um bloco de resina composta (Filtek Z350 XT; 3M/ESPE) foi confeccionado sobre a área preparada. Para a fotopolimerização, utilizou-se o fotopolimerizador LED Light Curing System - Demi Plus (Kerr Corporation, Middleton, WI, USA), com potência de 1200 mW/cm2 . A DT foi avaliada durante a fotopolimerização do adesivo por meio de um termômetro digital no interior da câmara pulpar. Os dados obtidos foram avaliados pelo MannWhitney test (5%). Resultados: Segundo Mann-Whitney test, o grupo ausência sofreu DT de 2 °C, enquanto o grupo presença variou 1 °C. Os valores de média da DT foram de 0.82±0.56 °C para o grupo presenca de PPS e 2.30 ± 0.73 °C para o grupo ausência de PPS. Conclusão: A pressão pulpar simulada reduziu significantemente a elevação de temperatura na câmara pulpar durante a fotopolimerização do sistema adesivo, demonstrando a importância de inserir esse protocolo de simulação de pressão pulpar nos procedimentos laboratoriais.(AU)

Alcoholic and isocaloric diet, but not ovariectomy, influence the apoptosis of bone cells within the alveolar bone crest of rats.

OBJECTIVE: Studies suggest that chronic alcoholism as well as oestrogen deficiencies may affect bones in general, including alveolar bone and, by doing so, increase individuals' susceptibility to develop progressive periodontal disease. This paper aims to verify the influence of chronic alcoholism and/or oestrogen deficiencies in the apoptosis of bone cells of the alveolar bone crest region in rats. DESIGN: Initially, 54 rats were divided into ovariectomized (Ovx) and Sham operated (Sham) groups. Thirty days after surgery, these two groups were equally sub-divided, and received, for 56 days, the following dietary intervention: alcoholic diet (with 20% alcohol solution,), isocaloric diet and ad libitum diet (free diet). Analysis was undertaken by immunohistochemistry, using an antibody to detect apoptosis (anti PARP p-85). RESULTS: When comparing the six experimental groups, no significant differences were observed in the apoptosis of bone cells. Also, there was no significant difference in the quantity of cells undergoing apoptosis when the animals from Ovx groups were compared with those from Sham groups. However, when comparing only different dietary groups, differences were observed between the groups ad libitum and isocaloric, to osteoblasts (p=0.045); and ad libitum and alcohol, to osteocytes (p=0.007). CONCLUSION: It is concluded that ovariectomy was not able to influence the rate of apoptosis of bone cells of the alveolar bone crest region in rats and that a possible influence of diet on apoptosis of osteoblasts and osteocytes cannot be ruled out.

Sistema adesivo universal: influência da técnica de condicionamento e da pressão pulpar com soro fetal bovino ou água deionizada na resistência de união à dentina humana / Universal adhesive system: influence of etch technique and pulpal pressure with bovine fetal serum or deionized water in bond strength of human dentin

A simulação da pressão pulpar é importante para reprodução das condições in vivo nos testes de resistência adesiva. Esse estudo avaliou a influência da pressão pupar simulada, utilizando soro fetal bovino ou água deionizada, na resistência de união à dentina do sistema adesivo Single Bond Universal (3M ESPE; Brasil Ltda.), in vitro, aplicado sob diferentes formas de condicionamento dentinário, ácido total e autocondicionante, através do teste de microtração. Setenta e dois molares humanos hígidos foram seccionados 1 mm abaixo da junção amelocementária para separação da coroa da porção radicular e seccionados paralelos à superfície oclusal para exposição de 2 mm de espessura de dentina. As amostras foram divididas aleatoriamente em 3 grupos: Grupo controle – sem pressão pulpar (n = 24); Grupo pressão pulpar soro – pressão pulpar com soro fetal bovino (n = 24); Grupo pressão pulpar água – pressão pulpar com água deionizada (n = 24). Em seguida, os espécimes foram divididos em 2 subgrupos (n = 12): Subgrupo condicionamento ácido total – ácido fosfórico 37% + SB Universal; Subgrupo autocondicionante – SB Universal. O sistema adesivo foi aplicado de acordo com a técnica de condicionamento dentinário ácido total ou autocondicionante, sob a simulação da pressão pulpar com 0 ou 15 cm de soro fetal bovino ou água deionizada (durante todo o procedimento restaurador). Os espécimes foram restaurados com a resina composta Filtek Z350 XT (3M ESPE). Após 48 h em água deionizada, os dentes foram seccionados para a obtenção de palitos com área adesiva de 1 mm2, e submetidos ao teste de microtração após 1 dia de armazenamento. A variação da resistência adesiva entre os grupos foi analisada pelos testes estatísticos ANOVA 2-fatores e Tukey (5% de significância). A maior média de resistência adesiva foi apresentada pelo grupo sem pressão pulpar simulada sob condicionamento dentinário autocondicionante (37,25 ± 4,12) e a menor média pelo grupo pressão pulpar simulada com líquido ...

The simulation of pulpal pressure is important for reproduction of in vivo conditions in tests of bond strength. This study evaluated the influence of the etching technique and simulated pulpal pressure with fetal bovine serum or deionized water on bond strength to dentin of Universal Single Bond (3M ESPE;. Brazil Ltda) in vitro. Seventy-two healthy human molars were cut 1 mm below the cemento-enamel junction to separate the crown of radicular portion and cut parallel to the occlusal surface for exposure of 2 mm thickness of dentin. Samples were randomly divided into 3 groups: control group – no pulpal pressure (n = 24); pulpal pressure group serum – pulpal pressure with bovine fetal serum (n = 24); pulpal water pressure group – pulpal pressure with deionized water (n = 24). Then, the subjects were divided into 2 subgroups (n = 12): Subgroup total etch – phosphoric acid 37 % + SB Universal; Self-etch subgroup – SB Universal. The adhesive system was applied according to the technique total-etch or self-etch under pressure simulation with pulp 0 or 15 cm bovine fetal serum or deionized water (throughout the restorative procedure). The specimens were restored with composite resin Filtek Z350 XT (3 m ESPE). After 48 h in deionized water, teeth were sectioned for obtaining beans with 1 mm² adhesive area, and subjected to the test,after 1 day of storage. The variation of bond strength between the groups was analyzed by ANOVA 2-way (simulated pulpal pressure and etch technique) and Tukey (5 % of significance). The highest average bond strength was presented by the group without simulated pulpal pressure self-etch (37.25 ± 4.12) and the lowest average by group simulated pulpal pressure with deionized water and self-etch procedure (26.12 ± 6, 46). There was statistically significant difference for the average bond strength of all groups tested without pressure (36.15a), pulpal pressure with bovin. fetal serum (31.06b) and simulated pulpal pressure with ...

In vitro evaluation of marginal leakage at enamel and dentin treated by different laser densities / Avaliação in vitro da infiltração marginal no esmalte e dentina tratada por diferentes densidades de laser

Objectives: To evaluate “in vitro” the degree of marginal leakage in class V cavities irradiated with Nd:YAG laser onto enamel and dentin pretreated with bonding system (Single Bond, 3M ESPE) without light-curing. Material & Methods: Class V cavities were performed and standardized in 60 bovine incisors. After the acid etching, the teeth were divided into three groups: G1 – Application of bonding system, irradiation with Nd:YAG laser at 140 mJ/pulse without light-curing. G2 – Application of bonding system, irradiation with Nd:YAG laser at 200 mJ/pulse without light-curing. Group C – Application of bonding system and light-curing. Next, resin composite restorations were executed and thermocycled at alternated baths from 2 to 50 ºC (± 2 ºC), totalizing 500 cycles. To assess the microleakage, the teeth were submersed into 50% silver nitrate solution for 24 h, cut at 1 mm of thickness and analyzed through stereoscopy. The following leakage criterion scores were employed: 0 – none leakage; 1 – gingival or incisal wall; 2 – axial wall towards the pulp. Results : It was observed a high leakage frequency with score 1 among the experimental conditions. There was a higher predominance of score 2 leakage for control group at cementum. Concerning to enamel and cementum, Group C was similar to G1. By comparing control group with G2, and G1 with G2, it was verified statistically significant differences. Conclusion: The laser energy provided a reduction of the marginal leakage at enamel and dentin/ cementum; however, the energy density increase resulted in smaller marginal leakage at enamel and dentin/cementum.

Objetivo: A presença de infiltração marginal é considerada a principal causa de fracasso clínico para restaurações em resina composta. Devido a isso alternativas para promover melhor vedação das margens foram desenvolvidas, como a utilização da energia do Nd:YAG laser. Portanto o objetivo deste estudo foi avaliar “in vitro” o grau de infiltração marginal em cavidades classe V irradiadas com Nd:YAG laser sobre esmalte e dentina bovinos pré-tratados com sistema adesivo Single Bond (3M ESPE) não-polimerizado. Material e métodos: Cavidades classe V padronizadas foram realizadas em 60 incisivos bovinos. Após realizar o condicionamento ácido, lavagem e secagem os dentes foram aleatoriamente divididos em 3 grupos: G1 – Aplicação do sistema adesivo, irradiação com Nd:YAG laser a 140 mJ/pulso em seguida a fotopolimerização. G2 – Aplicação do sistema adesivo, irradiação do Nd:YAG laser a 200 mJ/ pulso e fotopolimerização. Grupo C (Controle) – Aplicação do sistema adesivo, seguido da fotopolimerização. Restaurações em resina composta foram realizadas e em seguida submetidas a termociclagem em banhos alternados de 2º a 50ºC(±2ºC), totalizando 500 ciclos. Para a avaliação da microinfiltração, os dentes foram submersos em solução de nitrato de prata 50% por 24 h, os dentes foram cortados com 1 mm de espessura e então analisados os níveis de infiltração marginal ocorrida na interface dente-restauração, por meio de de lupa estereoscópica. Os critérios para a análise de infiltração foram: grau 0 – nenhuma infiltração; grau 1 – parede gengival ou incisal; grau 2 – parede axial em direção a polpa. Resultados: Observou-se alta frequência de infiltração marginal grau 1 entre as condições experimentais. Houve predomínio da infiltração grau 2 somente para o grupo controle em cemento. Nos grupos esmalte e cemento, o Grupo C não apresentou diferença estatística entre o G1...

Effect of caries infiltration technique and fluoride therapy on the bond strength of the demineralized enamel / Efeito da técnica de infiltração de cárie e fluorterapia na resistência adesiva ao esmalte desmineralizado

Different techniques are employed to control de caries progression, such as fluoride remineralization and resin infiltration (ICON®). However, the interference of these techniques on further adhesive procedures on the treated tissue is still controversial. The aim of this study was to evaluate the bond strength (BS) of the bovine enamel demineralized and treated with either fluoride or ICON®. Material and Methods: The tooth fragments were randomly divided into 4 groups: Group Sound samples (control); Group Demineralized samples (DS); Group Remineralized samples (NaF- 0.05% /8 weeks); Group ICON® samples. The samples were etched and next, a total etch bonding system was applied followed by resin composite. Then, they were submitted to microtensile test in a universal testing machine (10 Kg 1 mm/min). Results: Data were evaluated by ANOVA. There were statistically significant differences among groups (p = 0.28), with the following mean values (MPa): Group: Sound samples ((20,20 ± 2,97), Group: Demineralized Samples (21.99 ± 4.25), Group: Remineralized Samples (23.48 ± 4.03), Group: ICON® samples (22.10 ± 3,37). Conclusion: The treatments did not interfere in bond strength of the composite resin to enamel, providing values similar to those of the control group

Diferentes técnicas são empregadas como forma de controle da progressão da lesão cariosa, como a remineralização com flúor e a infiltração com resina (ICON®). No entanto, a interferência destas técnicas sobre futuros procedimentos adesivos no tecido tratado ainda mostra-se controversa. O objetivo do estudo foi avaliar a resistência adesiva (RA) em esmalte bovino desmineralizado e tratado com flúor ou com ICON®. Materiais e Métodos: Fragmentos dentais foram divididos aleatoriamente em 4 grupos: Grupo Espécimes íntegros (controle); Grupo Espécimes desmineralizados (ED); Grupo Espécimes Remineralizados (NaF- 0,05% /8 semanas); Grupo Espécimes ICON®. Sobre os espécimes tratados foi feito condicionamento ácido, aplicação de adesivo total etch e resina composta, sendo submetidos ao teste de microtração em máquina de ensaio universal (10Kg 1mm/min). Resultados: Os dados foram avaliados pelo teste ANOVA. Não houve diferença significante entre os grupos (p=0,28) sendo que, os valores médios em MPa obtidos para os diferentes grupos foram: Grupo: Espécimes Íntegros (20,20 ± 2,97), Grupo: Espécimes Desmineralizados (21,99 ± 4,25), Grupo: Espécimes Remineralizados (23,48 ± 4,03), Grupo: Espécimes ICON® (22,10 ±3,37). Conclusão: os tratamentos não interferiram na RA da resina composta ao esmalte, fornecendo valores semelhantes ao controle.