Objective: Toothbrushing with fluoride toothpaste followed by rinsing with mouthwash is a routine procedure to maintain good oral hygiene. It is unknown to what extent these rinses can modulate the effect of fluoride in its ability to prevent erosion/abrasion.The aim of this in-vitro study was to investigate and compare the impact of chlorhexidine (CHX), essential oils (EO) and cetylpyridinium chloride (CPC) mouthrinses on erosive tooth wear protection afforded by conventional fluoride toothpastes. Materials and Methods: The following experimental factors were considered: five rinses: CHX, EO, CPC, a fluoride rinse, and deionized water, two fluoride toothpastes: stannous fluoride (SnF2) or sodium fluoride (NaF) and two models: (erosion/ erosion+abrasion). Slabs of bovine enamel and dentin were prepared and embedded in resin blocks and generated 10 enamel and dentin testing groups (n = 8). UPVC tapes were placed on the sides of each slab leaving 1mm area exposed in the center. The blocks were subjected to a five-day cycling model. Then, the blocks were placed in a brushing machine and exposed to fluoride toothpaste slurry (one side was brushed and the other wasn’t). The blocks were then exposed to rinse treatments. Artificial saliva was used to remineralize the specimens after erosions and treatment challenges, and as storage media. After the fifth day of cycling, surface loss (in micrometers) was determined by profilometer. Data were analyzed using ANOVA (α = 0.05). Results: There was no interaction among the three factors (type of toothpaste, mouthrinse and abrasion or not (dentin p = 0.0520, enamel p = 0.4720). There were no significant two-way interactions as SL was only affected by toothpaste and mouthrinse. NaF caused less SL than SnF2 (4.60 vs. 5.83 μm; p < 0.0001) in dentin, whereas the opposite was found in enamel (5.20 vs. 3.56 μm; p < 0.0001). Toothbrushing abrasion caused comparatively more SL in enamel (6.53 vs. 2.23 μm; p < 0.0001) than in dentin (6.06 vs. 4.38 μm; p < 0.0001). None of the tested mouthrinses affected SL. Conclusion: Commonly used mouthrinses containing antimicrobial agents or additional fluoride, do not impair the erosion/abrasion protection afforded by fluoride toothpastes. Tested SnF2 dentifrice offered greater protection against enamel surface loss and NaF dentifrices showed more protection for the dentin surface. Clinical relevance: The understanding of the interaction between commonly used rinses and fluoride dentifrices will help dentists provide better recommendations to patients with erosive lesions.

Indiana University-Purdue University Indianapolis (IUPUI) / Potential problems of one-step adhesives have been identified, including water uptake and subsequent plasticization, water-and enzyme-induced nanoleakage, and the presence of voids due to phase-separation or osmosis. Clinically, adhesive failures due to marginal degradation present as retention loss, marginal discoloration, and secondary caries. However, the mechanisms of adhesive interface degradation of self-etching and self-bonding resin luting agents are not fully understood. The objective of the study was to investigate adhesive layer degradation by using a nanoleakage technique with five different resin luting agents. Materials and Methods: Five different resin luting systems, Variolink II, Panavia F2.0, RelyX Unicem, RelyX Unicem2, and Maxcem Elite were evaluated in this study. The 25 dentin specimens were randomly divided into five resin luting agent groups. Flat dentin surfaces were created mid-coronally and were luted with luting agents. Then, each tooth was sectioned occluso-gingivally. The first half of each tooth was used as a control group and the other half was used as the experimental group. The control group was immersed in artificial saliva at 37°C and SEM examination with chemical analysis was performed within 48 hours. In the tested group, all specimens were immersed in artificial saliva at 37°C for 10 days and thermocycled. For the SEM examination, the specimens were immersed in a 50-percent ammoniacal silver nitrate solution for 24 hours.22 SEM was used for observation of silver penetration of the specimens. Three scan lines were selected. For elemental analysis, natural apatite, olivine minerals, and pure silver metal were chosen as standards for Ca, Si and Ag. Data were analyzed using ANOVA with a 5-percent significance level. Results: At the bottom of the hybrid layer, there was no significant difference in silver uptake within the adhesive interface between luting agents (p > 0.05) and there was no significant change in silver uptake within the adhesive interface after thermocycling (aging) (p > 0.05). Conclusion: All resin luting agents exhibited nanoleakage after both 24-hour storage and 10-day storage with thermocycling.

The purpose of this study was to compare the thickness of dentin removed from the buccal root of bifurcated maxillary first premolars (BMFP) in the area of furcation groove after instrumentation with WaveOne and LightSpeed LSX files utilizing limited field cone beam computerized tomography. All data was analyzed using repeated-measured mixed-model ANOVA and differences were described using Tukey’s multiple comparison procedure. The thickness of dentin removed with LightSpeed LSX files (0.1 mm) was significantly less than the thickness of dentin removed with WaveOne files (0.2 mm). To conclude, LSX files remove a more predictable and consistent thickness of dentin from the buccal root of BMFP, irrespective of the pre-instrumentation thickness of dentin and the file size when compared to WO files that remove a more variable thickness of dentin.

Purpose: To compare the in-vitro shear bond strengths of a new paste-paste formulation of resin-modified glass-ionomer cement (Rm-GIC) to an exising powder-liquid formulation. The study will test the hypothesis that the new paste-paste formulation of Rm-GIC (Fuji-Cem ™, GC Corp, Tokyo, Japan) has the same bond strength as an existing popular powder-liquid formulation of Rm-GIC (Rely-X ™ Luting Cement, 3M, St. Paul, MN)Materials and Methods: A total of 33 human molars were sectioned parallel to the occlusal surface to expose mid-coronal dentin and mounted parallel to the bond shearing device on the universal testing machine (Instron). For Group I samples (Rely-X, n=15), the powder and liquid were measured and adjusted to achieve a ratio of 1.6 and mixed for 30 seconds as recommended by the manufacturer. For Group II (Fuji-Cem, n=18), the paste-paste was expressed from the paste-dispenser provided by the manufacturer and mixed for 10 seconds as recommended. After testing, the teeth from group II were bonded on a different site with the same material but mixed for 20 seconds (n=18). To ensure a uniform flow and bond surface area, the mixed cement was syringed into a cylindrical mould (diameter 2.38mm, height 2mm) and allowed to set under constant force. All samples were subjected to fracture by shear loading on a universal testing machine (Instron) at a uniform crosshead speed of .02" per minute and expressed as MPa. Values were analyzed at the pResults: Wilcoxon rank sums test showed significantly higher shear bond strength values for Rely-X compared to Fuji-Cem mixed both at 10 seconds and 20 seconds. Mixing for 20 seconds resulted in stronger bonds for Fuji-Cem compared to 10 seconds, but was still significantly lower than Rely-X.Conclusions: Within the limitations of the study, the Rely-X powder-liquid formula shows a significantly stronger dentin shear bond strength when compared to the new paste-paste formula of resin-modified glass ionomer cement, Fuji-Cem.

Statement of problem. Clinicians have used disinfection materials to remove surface contaminants during cavity preparation. It has been postulated that disinfection materials may negatively affect shear bond strength of restorative materials. If so, large numbers of restorations may be predestined for early failure with the use of a disinfection protocol.Purpose. To determine whether there is a difference in the bond strength between dentin and composite resin with a 3-step disinfection technique compared to a conventional bonding technique without the additional disinfection protocol.Material and Methods. Sixty human molar teeth were sectioned parallel to the occlusal surface to expose mid-coronal dentin and mounted parallel to a bond shearing device on a universal testing machine (Instron) and randomly divided into 2 groups. In Group I (n=30), specimens were treated with chlorhexidine, tubulicid red, and sodium hypochlorite before dentin bonding, following the manufacturer's instructions for All Bond 2. In Group II (n=30), specimens were treated only with the bonding protocol of All Bond 2. To ensure a uniform bond surface area, core paste was syringed into a cylindrical mold (diameter 2.38mm, height 2.00mm) that was in contact with the dentin bonding surface of each specimen, and allowed to set under constant force. All specimens were subjected to fracture by shear loading in a universal testing machine (Instron) at a uniform crosshead speed of 0.02 inch per minute and expressed as MPa. Statistical analysis, using nonpaired student's t-test, was performed. Results. A statistically-significant higher shear bond strength was found for the 3-step disinfection group (mean shear bond strength, 25.3; STD, 4.6) compared to the conventional bonding group (mean shear bond strength, 20.5, STD, 3.4) (PConclusions. The 3-step disinfection technique group showed a significantly stronger dentin shear bond strength compared to the conventional bonding technique without disinfection.

O objetivo deste estudo clínico foi avaliar a influência da quitosana na biomodificação da dentina após a remoção seletiva das lesões de cárie com o laser de Er:YAG em dentes decíduos, quanto à redução da quantidade de Streptococus mutans e Lactobacillus ssp, e o comportamento clínico das restaurações realizadas. A amostra foi composta por 52 crianças que apresentaram lesão de cárie ativa atingindo dentina, localizada na superfície oclusal em molar decíduo. Para a análise microbiológica (n=10), os dentes foram distribuídos aleatoriamente em 4 grupos de acordo com a remoção seletiva das lesões de cárie: laser de Er:YAG (250mJ/4Hz) ou contra-ângulo (método convencional) e o tratamento da superfície da dentina: sem biomodificação e com biomodificação (gel de quitosana a 2,5%). Foram realizadas coletas da dentina infectada, dentina afetada e após a biomodificação com gel de quitosana a 2,5%. As unidades formadoras de colônias (UFC/mg) foram contadas e os dados foram analisados por meio do teste Shapiro-Wilk e teste de Mann-Whitney para o laser de Er:YAG após aplicação da quitosana. Após a remoção seletiva da lesão de cárie com o laser de Er:YAG houve redução significativa na quantidade de S. mutans (p=0,0068). Para Lactobacillus ssp não foi observada diferença significante entre os métodos de remoção (p=0,089). Após a biomodificação com gel de quitosana a 2,5%, houve redução significativa na quantidade de S. mutans, para ambos os métodos de remoção (p=0,0524). A aplicação de quitosana promoveu redução da quantidade de Lactobacillus ssp, após remoção seletiva pelo método convencional, mas não com laser de Er:YAG (p=0,000487). Para a análise clínica os dentes foram restaurados com adesivo (Single Bond Universal/3M) e resina composta (Z350 Filtek/3M) e avaliados nos períodos de 7 dias (baseline), 6 meses e 1 ano, utilizando os critérios USPHS modificados. Foram realizadas imagens fotográficas para auxiliar na análise clínica das restaurações. Para análise da adaptação marginal da réplica da restauração em microscopia eletrônica, os dentes foram moldados com silicona de adição. Os dados obtidos na análise clínica foram submetidos aos testes não-paramétrico de Kruskal Wallis e complementar de Dun (p< 0.05). Na análise clínica observou-se diferença significativa para a remoção seletiva da lesão da cárie utilizando o laser de Er:YAG com relação aos critérios descoloração e adaptação marginal (p<0,05). Concluiu-se que o laser de Er:YAG reduziu a quantidade de S. mutans e Lactobacillus ssp e a biomodificação com gel de quitosana a 2,5% foi efetiva para potencializar o efeito antimicrobiano, e que o comportamento clínico das restaurações não foi influenciado pelo método de remoção da lesão de cárie e biomodificação da dentina afetada / The objective of this clinical study was to evaluate the effect of Er: YAG laser for the removal of caries lesions in primary teeth, followed by the biomodification of dentin affected with 2.5% chitosan gel, reducing the amount of Streptococcus mutans and Lactobacillus ssp, and the clinical behavior of the performed restorations. The sample consisted of 52 children who presented lesions of active caries reaching dentin, located on the occlusal surface in a deciduous molar. For the microbiological analysis (n = 10), the teeth were randomly distributed in 4 groups according to the selective removal of caries lesions: Er: YAG laser (250mJ / 4Hz) or contra-angle (conventional method) and treatment of the dentin surface: without biomodification and with biomodification (chitosan gel). Dentin tissue was collected in three periods: before selective removal of the caries lesion, after selective removal of the caries lesion and after the dentin biomodification with chitosan gel. The colony forming units (CFU/mg) were counted and the data were analyzed by means of the Shapiro-Wilk test and Mann-Whitney test for the Er: YAG laser after application of chitosan. After the selective removal of the caries lesion with Er:YAG laser there was a significant reduction in the amount of S. mutans (p = 0.0068). For Lactobacillus ssp, no significant difference was observed between the removal methods (p = 0.089). After biomodification with 2.5% chitosan gel, there was a significant reduction in the amount of S. mutans, for both removal methods (p=0.0524). The application of chitosan promoted reduction of the amount of Lactobacillus ssp after selective removal by the conventional method, but not with Er: YAG laser (p = 0.000487). For the clinical analysis, the teeth were restored with adhesive (Single Bond Universal / 3M) and composite resin (Z350 Filtek / 3M) and evaluated in 7-day periods (baseline), 6 months and 1 year using modified USPHS criteria. Photographic images were taken to aid in the clinical analysis of the restorations. For analysis of the marginal adaptation of the replica of the restoration in electron microscopy, the teeth were molded with addition silicone. The data obtained in the clinical analysis were submitted to nonparametric Kruskal Wallis tests and Dun\'s complement (p<0.05). In the clinical analysis, a significant difference was observed for the selective removal of the caries lesion using the Er: YAG laser in relation to the descoloration and marginal adaptation criteria (p<0.05). It was concluded that the Er: YAG laser reduced the amount of S. mutans and Lactobacillus ssp and the biomodification with chitosan was effective to potentiate the antimicrobial effect, and that the clinical behavior of the restorations was not influenced by the method of removing the lesion from caries and biomodification of the affected dentin

O objetivo deste estudo foi avaliar o efeito da remoção seletiva da lesão de cárie utilizando laser de Er:YAG, seguida da biomodificação da dentina com quitosana. Os objetivos específicos foram: 1) Avaliar os elementos químicos e a morfologia da superfície dentinária, bem como, a microdureza da subsuperfície (experimento 1) e 2) Avaliar a resistência de união da interface resina/dentina e sua morfologia após 24h, 6 e 12 meses de envelhecimento dos espécimes, a perda de massa seca e a resistência à degradação do colágeno (experimento 2). Lesões de cárie em dentina foram criadas pelo método de ciclagem do pH (14 dias) em 208 espécimes bovinos. Os espécimes foram divididos de acordo com método de remoção seletiva da lesão de cárie: broca (em baixa rotação) ou laser de Er:YAG (250 mJ/4Hz). Os espécimes receberam ácido fosfórico a 35%, e foram subdivididos de acordo com a biomodificação da dentina: sem biomodificação ou quitosana a 2,5%. No experimento 1, os espécimes foram submetidos às análises de Espectroscopia Eletrônica de Análise Química (EDS) e Microscopia Eletrônica de Varredura (MEV) da superfície e microdureza da subsuperfície dentinária. No experimento 2, os espécimes foram submetidos a resistência de união à microtração e MEV da interface adesiva após 24h, 6 e 12 meses de armazenamento em água, avaliação da perda de massa seca e liberação de hidroxiprolina (HYP). Os dados foram analisados por meio de testes paramétricos e não paramétricos (=0.05). A remoção seletiva da lesão de com laser de Er: YAG promoveu aumento da microdureza da dentina afetada (p=0,03) e redução na quantidade de Ca (0<0,0001) e P (0<0,0001). A biomodificação com quitosana não influenciou a microdureza (0,0796) e a porcentagem atômica dos elementos Ca (p=0,2269) e P (p=0,8842) presentes na dentina residual. A análise em MEV mostrou alterações morfológicas na superfície de dentina (p>0,05). Após 24h, os maiores valores de resistência de união foram obtidos para a broca em comparação ao laser Er:YAG (p<0,001). Após 6 meses, os métodos foram semelhantes (p=0,432) e após 12 meses a resistência de união à dentina irradiada foi significativamente maior do que à dentina tratada com broca (p=0,025). A biomodificação com quitosana aumentou significativamente a resistência de união à dentina após 6 (p=0,011) e 12 meses (p<0,001). A análise em MEV mostrou que a biomodificação com quitosana preservou a interface adesiva após 12 meses de armazenamento. A perda de massa seca (p>0,664; p>0,263) e a liberação de hidroxiprolina (p>0,6347; p>0,4274) não foram influenciadas, respectivamente, pelo método de remoção da cárie ou pela biomodificação dentinária. A remoção seletiva da dentina cariada com o laser de Er: YAG aumentou a microdureza da dentina afetada por cárie, alterando sua morfologia superficial e composição química. A biomodificação com quitosana não influenciou a composição estrutural e química da dentina residual. Após 24h de armazenamento em gua, a resistência de união da resina composta à dentina foi afetada pelo laser de Er:YAG. No entanto, a resistência de união à dentina irradiada foi mantida, enquanto a dentina tratada com broca apresentou redução contínua. A biomodificação com quitosana, independente do método de remoção utilizado, preservou a resistência de união e a interface adesiva ao longo de 12 meses. O laser de Er:YAG e a biomodificação com quitosana não influenciaram na perda de massa seca e na liberação de hidroxiprolina / The aim of this study was to evaluate the effect of Er:YAG laser for selective removal of carious lesion, followed by biomodification with chitosan. The specific objectives were: 1) To evaluate the chemical elements and the morphology of the dentin surface, as well as, the subsurface microhardness (Experiment 1). 2) To evaluate the microtensile bond strength (TBS) and adhesive interface after 24h, 6 and 12 months of water storage, the dry mass loss and dentin collagen degradation (Experiment 2). Dentinal caries lesions were created in 208 bovine specimens by pH-cycling method (14 days). Specimens were divided according to the carious removal method: bur (low-speed handpiece) or Er:YAG laser (250 mJ/4Hz). Specimens were treated with 35% phosphoric acid and were subdivided according to dentin biomodification: without chitosan (control) and 2.5% chitosan. For the experiment 1, specimens were submitted to Energy Dispersive X-Ray Spectroscopy (EDS) and Scanning Electron Microscopy (SEM) and subsurface microhardness of the dentin. For the experiment 2, specimens were submitted to microtensile bond strength and SEM analysis of the adhesive interface after 24h, 6 and 12 months of storage in water, evaluation of dry mass loss and hydroxyproline release (HYP). Data were analyzed by parametric and non-parametric tests (=0.05). The selective caries removal with Er:YAG laser increased the microhardness value of caries-affected dentin (p=0.03) and reduced the amounts of Ca (0<0.0001) and P (0<0.0001). The biomodification with chitosan did not influence the microhardness (0.0796) and atomic percentage of Ca (p=0.2269) and P (p=0.8842) of residual dentin. SEM analysis showed morphological changes on dentin surface (p>0.05). After 24h, the highest bond strength values were found for bur compared to Er:YAG laser (p<0.001). After 6 months, methods were similar (p=0.432) and after 12 months, the highest bond strength values were found for Er:YAG laser-irradiated dentin (p=0.025). Biomodification with chitosan significantly increased bond strength to dentin after 6 (p=0.011) and 12 months (p<0.001). SEM analysis showed that the biomodification with chitosan preserved the adhesive interface after 12-month storage. The dry mass loss (p>0.664; p>0.263) and HYP release (p>0.6347; p>0.4274) were not influenced, respectively, by the carious removal method or by dentin biomodification. The selective removal of carious dentin with Er:YAG laser increased microhardness of residual caries-affected dentin changing its surface morphology and chemical composition. The biomodification with chitosan did not influence the structural and chemical composition of residual dentin. After 24 hours of water storage, the composite resin bond strength to dentin was affected by Er:YAG laser. However, the bond strength to irradiated-dentin was maintained, while the bur-treated dentin showed a continuous reduction. Biomodification with chitosan, regardless of removal method used, preserved the bond strength and adhesive interface over 12 months. The dry mass and the hydroxyproline release were not influenced

Quitosana é um biopolímero natural obtido a partir da desacetilação de quitina. Embora a quitosana já seja utilizada na Odontologia, seu papel sobre o substrato dentinário de dentes decíduos não está bem elucidado. Portanto, o objetivo do presente estudo foi avaliar o papel da incorporação do gel de quitosana a 2,5 % na dentina de dentes decíduos afetada por lesão de cárie. Dentes decíduos extraídos foram coletados e submetidos à indução de lesão de cárie artificial. Após teste de microdureza inicial (n=28), os dentes foram estratificados para receber gel de quitosana a 2,5%. A superfície dentinária hígida (n=3), dentina desmineralizada (n=3) e dentina biomodificada com gel de quitosana a 2,5% (n=3) foram submetidas à Espectroscopia de Energia Dispersiva de Raio-X (EDS) e Microscopia Eletrônica de Varredura (MEV). O teste de microdureza também foi realizado após a indução de lesão de cárie artificial e após a biomodificação da dentina. Os dados foram avaliados usando o teste paramétrico one-way ANOVA para medidas repetidas. A análise dos dados para EDS foi efetuada por meio de teste não paramétrico de Kruskal-Wallis seguido pelo ajuste dos valores de significância pela correção de Bonferroni para múltiplos testes, bem como por meio de estatística descritiva dos dados obtidos através da fórmula: Variável de estudo controle/ controle × 100. A biomodificação da dentina não alterou a microdureza da superfície dentinária (p=0,339). A porcentagem atômica de cálcio revelou diferenças estatisticamente significantes antre a dentina hígida e biomodificada com quitosana (p<0.022), assim como a porcentagem atômica de fósforo que se mostrou superior no grupo que sofreu a biomodificação. A MEV revelou um expressivo número de túbulos dentinários obliterados, porém com maior diâmetro. As imagens topográficas revelaram, ainda, uma superfície lisa e regular após a biomodificação. Embora a aplicação do gel de quitosana a 2,5% na dentina parcialmente desmineralizada em dentes decíduos não foi capaz de aumentar o valor de microdureza, a biomodificação gerou uma superfície dentinária apropriada para procedimentos restauradores adesivos / Chitosan is a natural biopolymer obtained from chitin deacetylation. Although chitosan is already used in dentistry, this role on the primary teeth dentin substrate is not well elucidated. So, the aim to this study was to evaluate the role of the 2.5% chitosan gel incorporation in primary caries-affected dentin teeth. Extracted primary teeth were collected and submitted to artificial caries induction. Teeth were stratified to receive 2.5% chitosan gel after dentin microhardness initial test (n= 28). Healthy dentin (n=3), demineralized dentin (n=3) and biomodified dentin with 2.5% chitosan gel (n=3) were submitted to Energy Dispersive X-ray Spectroscopy (EDS) and Scanning Electron Microscopy (SEM). Microhardness Test was performed too after artificial caries induction and after dentin biomodification. Data were evaluated using one-way ANOVA repeated measures parametric test. Data analysis for EDS was performed using non-parametric Kruskal-Wallis test followed by adjustment of significance values by Bonferroni correction for multiple tests, as well as by means of descriptive statistics of the data obtained using the formula: Study variable control/control × 100. Dentin biomodification did not alter the subsurface microhardness of dentin (p=0,339). The calcium atomic percentage showed statistically significant differences between healthy and biomodificated dentin (p<0.022) and too presented superior phosphorus atomic percentage. SEM revealed expressive number of dentinal tubules obliterated, but a larger diameter. Topographic images revealed a smooth and regular surface in biomodified dentin. Although 2.5% chitosan gel application on partially demineralized dentin in primary teeth was not able to increase microhardness, the biomodification generated an appropriate dentin surface for adhesive restorative procedures

O desenvolvimento de adesivos bioativos mostra-se como uma alternativa interessante para agregar benefícios aos novos materiais. O objetivo do estudo foi sintetizar nanopartículas de prata (NAg) e de hidroxiapatita (NHA), avaliar sua influencia no efeito antibacteriano, citotoxicidade de um adesivo com NAg e sua resistência de união à dentina associado ao uso de NHA. As nanopartículas foram caracterizadas por fluorescência de raio x por reflexão total (TRXF), difratometria de raio x (DRX), microscopia eletrônica de transmissão (TEM) e espalhamento de luz visível (DLS). O sistema Scotchbond Multi-Purpose (SBMP) foi modificado com adição de 0,05% e 0,1% de NAg no primer e no bond. Molares humanos foram restaurados com o sistema adesivo modificado após o pre-tratamento da dentina com suspensão aquosa de NHA a 0,5% e 1% para realização do ensaio de resistência de união imediata (24h) e após 1 ano de envelhecimento. A interface adesiva foi caracterizada por Microscopia Confocal Raman (MCR). Para mensurar o efeito antibacteriano (S.mutans) do adesivo com NAg foi realizado o ensaio de difusão em ágar com template e contagem de Unidades Formadoras de Colônias (UFC). A citotoxicidade foi avaliada com uso de células tronco da polpa dentária (DPSCs) em contato com adesivos não polimerizados e polimerizados em diferentes concentrações de meio condicionado (0% 25%, 75% e 100%). Foram produzidas NAg esféricas, com estrutura cúbica de face centrada, e com 16 nm de diâmetro médio. As NHA exibiram estrutura prismática com tamanho médio de 79,4 nm. O adesivo com NAg e o tratamento da dentina com NHA não afetaram a resistência de união imediata ou após 1 ano de envelhecimento, e as interfaces adesivas mostraram-se íntegras. Os adesivos modificados por NAg exibiram citotoxicidade similar ao adesivo controle e maior efeito antibacteriano. Os adesivos com adição de NAg são promissores quanto à obtenção de um material bioativo antimicrobiano que não altera a resistência de união ou a biocompatibilidade. / The development of bioactive adhesives is shown an interesting alternative to add benefits to the new materials. The aim of the study was to synthesize silver nanoparticles (NAg) and hydroxyapatite (NHA) and to evaluate their influence on the bond strength, antimicrobial effect, and biomaterials cytotoxicity. The nanoparticles were characterized by x-ray fluorescence by total reflection (TRXF), x-ray diffractometry (XRD), transmission electron microscopy (TEM) and visible light scattering (DLS). The Scotchbond Multi-Purpose system (SBMP) was modified with 0.05% and 0.1% silver in the primer and bond. Human molars were restored with the modified adhesive after pre-treatment of dentin with 0.5% and 1% NHA for the immediate bond strength test (24h), and after 1 year of aging. The adhesive interface was characterized by Confocal Raman Microscopy (MCR). To measure the antibacterial effect (S.mutans) of the adhesive with NAg, the agar diffusion assay with template was performed and counting of Colony Forming Units (UFC). In order to evaluate the cytotoxicity, dental pulp stem cells (DPSCs) were used in contact with unpolymerized and polymerized adhesives in different concentrations of conditioned medium (0% 25%, 75% and 100%). Spherical NAg, with a cubic face centered structure, and 16 nm in diameter were produced. The NHA exhibited a prismatic structure with approximately 79.4 nm. The adhesive with NAg and the treatment of dentin with NHA did not affect the bond strength immediately or after 1 year of aging, and the adhesive interfaces were shown to be intact. NAg-modified adhesives exhibited cytotoxicity similar to the control adhesive and higher antibacterial effect. The adhesives with NAg addition are promising in obtaining a bioactive antimicrobial material that does not alter the bond strength or the biocompatibility.

O objetivo do presente estudo foi avaliar o efeito da biomodificação com carbodiimida e quitosana fosforilada na dentina afetada por cárie. A amostra foi composta por 75 espécimes de dentina bovina submetidos à indução de lesão de cárie pelo método de ciclagem do pH (8h em solução desmineralizante e 16h em solução remineralizante) durante 14 dias. Foi realizada a remoção seletiva da lesão de cárie com broca em baixa rotação. Os espécimes foram divididos de acordo com a biomodificação da dentina: sem biomodificação (controle), carbodiimida (EDC) e quitosana fosforilada (P-chi). Os espécimes foram condicionados com ácido fosfórico 35%, e tratados com o agente biomodificador correspondente. Os espécimes foram restaurados com adesivo (Single Bond Universal - 3M ESPE) e resina composta (Z250 - 3M ESPE). Trinta espécimes foram submetidos à análise de microdureza da subsuperfície dentinária em quatro momentos: dentina hígida, dentina afetada por cárie, após a remoção seletiva da lesão de cárie (dentina residual) e, após a restauração dos espécimes. Os 36 espécimes restantes foram submetidos a ensaio de resistência de união à microtração (&mu;TBS) realizado após 24 h e 6 meses de armazenamento em água e microscopia eletrônica de varredura (MEV). Os dados foram analisados por meio de testes paramétricos e não paramétricos (&alpha;=0,05). A biomodificação da dentina residual afetada por cárie com EDC e P-chi não alterou a microdureza da subsuperfície dentinária (p=0,141). Na análise de &mu;TBS, não foram encontradas diferenças significativas entre os grupos 24 h e após 6 meses de armazenamento. Ao longo do tempo, o grupo controle (p<0,001) teve redução da &mu;TBS, o grupo EDC (p=0,099) foi capaz de manter a &mu;TBS e o grupo P-chi (p=0,005) promoveu aumento da &mu;TBS. A análise de MEV mostrou que os biomodificadores preservaram a interface adesiva após 6 meses de armazenamento. A biomodificação com carbodiimida e quitosana fosforilada não influenciou a microdureza da subsuperfície da dentina afetada por cárie, porém foi capaz de inibir a degradação da interface adesiva, mantendo a resistência de união da resina composta à dentina afetada após 6 meses de armazenamento em água / The aim of this study was to evaluate in vitro the effect of biomodification with carbodiimide and phosphorylated chitosan on caries affected dentin. The sample was composed by 75 bovine incisors, submitted to caries induction by pH cycling (8h in demineralizing solution and 16h in remineralizing solution) for 14 days. The selective caries removal was performed with bur at low-speed handpiece. Specimens were divided according to the dentin biomodification: no biomodification (control), carbodiimide (EDC) and phosphorylated chitosan (P-chi). All specimens were conditioned with 35% phosphoric acid and then treated with the correspondent biomodificator. Specimens were restored with an adhesive system (Single Bond Universal - 3M ESPE) and composite resin (Z250 - 3M ESPE). Thirty specimens were submitted to subsurface microhardness test in four periods of time: on sound dentin, on caries-affected dentin, after the selective removal of caries (residual caries-affected dentin) and after the restoration. The remaining 36 specimens were submitted to microtensile bond strength test (&mu;TBS) after 24 h and 6 months of water storage and to scanning electron microscopy analysis (SEM). Data were statistically analyzed by parametric and non-parametric tests (&alpha;=0.05). The biomodification of residual caries-affected dentin with EDC and P-chi did not change the subsurface microhardness (p=0.141). In the &mu;TBS test, there were no significant difference between groups at 24 h and 6 months of water storage. Over time, the control group (p<0.001) had a decreased on the &mu;TBS, the EDC group (p=0.099) was capable of maintained &mu;TBS and the P-chi group (p=0.005) increased in &mu;TBS. SEM analysis showed that biomodification preserved the adhesive interface after 6 months of water storage. The biomodification with carbodiimide and phosphorylated chitosan did not influence the subsurface microhardness of caries-affected dentin, however, it was capable of inhibit degradation of the adhesive interface, maintaining the microtensile bond strength of the composite resin to caries affected dentin after 6 months of water storage