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The incorporation of metallic oxides in dental adhesives has been a strategy to confer improved radiopacity and physicochemical properties for polymers. Tailoring the structure of these fillers could contribute to their application in therapeutic strategies for dental restorations. The aim of this study was to evaluate the incorporation of niobic acid into experimental dental adhesives, and compare these adhesives to niobium pentoxide containing adhesives. A control group without Nb2O5·n H2O or Nb2O5 was also used for comparison. Niobium-based particles have been used as a feasible approach, mainly because of their bioactivity. In this study, hydrated niobium pentoxide, also called niobic acid (Nb2O5·n H2O), was incorporated into an experimental dental adhesive as a potential catalyst for monomer conversion. A base resin for dental adhesive was formulated with methacrylate monomers and photoinitiators. Two types of oxides were tested as filler for this adhesive: Nb2O5·n H2O or niobium pentoxide (Nb2O5). Both fillers were added separately into the experimental adhesive at 0, 2.5, 5, and 10 wt.%. One group without Nb2O5·n H2O or Nb2O5 (0 wt.% of filler addition) was used as a control group. The formulated materials were analyzed for radiopacity according to the ISO 4049 and used FTIR analysis to assess the degree of conversion (DC) and the maximum polymerization rate (RPmax). Mechanical properties were analyzed by ultimate tensile strength (UTS) in a testing machine. Softening in solvent was conducted by measuring Knoop microhardness before and after immersion of samples in ethanol. Normality of data was assessed with Shapiro-Wilk, and comparisons between factors were conducted with two-way ANOVA and Tukey at 5% of significance. Both fillers, Nb2O5 or Nb2O5·n H2O, increased the radiopacity of dental adhesives in comparison to the unfilled adhesive (p < 0.05). There were no differences among groups for the ultimate tensile strength (p > 0.05), and all groups containing Nb2O5 or Nb2O5·n H2O improved the resistance against softening in solvent (p < 0.05). The groups with 5 and 10 wt% addition of Nb2O5 showed decreased DC compared to the control group (p < 0.05), while the addition of Nb2O5·nH2O up to 10 wt% did not alter the DC (p > 0.05). The polymerization rate did not change among groups (p > 0.05). In conclusion, Nb2O5·n H2O is a promising filler to be incorporated into dental adhesives providing proper mechanical properties, improved resistance against solvents, and increased radiopacity, without changing the DC.

Aim: The aim of this study was to develop an experimental adhesive resin with nanoneedle-like zinc oxide (N-ZnO), an inorganic filler, that could avoid particle agglomeration and lead to a homogeneous stress distribution within the material and characterize it. Materials and Methods: N-ZnO particles obtained by a thermal evaporation technique were characterized regarding size and surface area and added at 0 (control), 1, 2, 5, and 10 wt%, to an experimental adhesive resin. The following experimental adhesive resins' properties were assessed: radiopacity, contact angle to conditioned enamel and dentin, color, degree of conversion, flexural strength, resistance to degradation, and cytotoxicity. Statistical analysis was performed using one-way ANOVA and Tukey's post hoc test and paired Student's t-test. Results: Particles presented a mean particle size of 40 nm and a specific surface area of 16 m2/g. N-ZnO10%showed an increased radiopacity when compared to N-ZnO0%. Contact angles were significantly higher for N-ZnO10%at enamel and N-ZnO2%, N-ZnO5%, and N-ZnO10%at dentin. All groups showed color change when compared to N-ZnO0%. Higher the N-ZnO concentration, lower the degree of conversion. There were no significant differences between the groups for flexural strength and resistance to degradation. The addition of N-ZnO showed no difference in cytotoxicity when compared to positive control, N-ZnO0%, and all groups showed higher values than negative control. Conclusions: N-ZnO possibly exceeded potential limitations due to particles' agglomeration and improved the transference and distribution of stress within the material. It could be effectively used as a filler for adhesive resins.

Objective: The aim of this study was to compare the performance of two nickel-titanium rotary systems regarding the preparation time, final shape of canal, incidence of aberration, transportation, and fracture of instrument. Methods: A total of 40 simulated canals in resin blocks with 30o curves and a length of 17 mm were divided randomly into two groups: preparation with ProTaper and BioRaCe systems up to F5 and BR5 respectively. Pre- and post-operative canal images were taken and superimposed in order to identify aberrations, transportation, and to take measurements of the canal width. In addition, the preparation time and instrument fractures were recorded. The data were analyzed using Student's t test. Results: There is no difference (p>.05) comparing the systems regarding preparation time, canal aberration, and instrument fracture rates. The progressive tapered instruments of ProTaper prepared significantly larger canal widths in the apical third (p

Objetivo: Avaliar quatro sistemas adesivos comerciais de diferentes composições quanto ao desempenho da resistência da união à dentina. Métodos: Vinte incisivos bovinos tiveram a dentina vestibular exposta e receberam restaurações de resina confeccionadas com quatro (n=5) diferentes sistemas adesivos simplificados: Magic Bond DE e OptiBond Solo (convencionais), One-Up Bond F e Adper Prompt L-Pop (auto-condicionantes). Os dentes foram seccionados perpendicularmente a interface adesiva utilizando-se um disco de diamante, de modo a se obter palitos de 1mm² de área de secção. Os palitos foram submetidos ao ensaio de micro-tração em uma máquina de ensaios universal. Os valores médios de resistência de união dos diferentes sistemas adesivos foram comparados utilizando-se ANOVA de uma via e teste Tukey, em um nível de significância de 5%. Resultados: Os valores médios de resistência da união foram 48,81±0,56 para o Magic Bond DE, 47,52±13,03 para o OptiBond Solo, 44,68±13,32 para o One-Up Bond F e 31,59±11,81 para o Adper Prompt L-Pop. O adesivo Adper Prompt L-Pop apresentou resistência de união inferior a dos adesivos convencionais (p

Objetivo: Avaliar a influência do pré-condicionamento da dentina com ácido fosfórico sobre a resistência de união de dois sistemas adesivos autocondicionantes de dois passos. Métodos: Foram utilizados 32 incisivos bovinos, divididos aleatoriamente em 4 grupos. Os grupos receberam a aplicação dos sistemas adesivos autocondicionantesClearFil SE Bond (GCL) ou AdheSE (GAD). Dois grupos, GADpa e GCLpa, receberam, antes da aplicação do primer, o condicionamento com ácido fosfórico. Em cada dente foram confeccionados seis restaurações cilíndricas com área adesiva de 0,88 (± 0,03) mm2. Após 24 horas, os dentes foram submetidos ao ensaio de microcisalhamento, em uma máquina de ensaios universal, com uma velocidade de 1mm/min. A análise dos dados foi realizada com ANOVA de dois fatores a um nível de significância de 5%. Resultados:Os valores médios de resistência de união variaram entre 16,25 e 21,71 MPa, entretanto não houve diferença estatisticamente significativa entre todos os grupos avaliados (p>0,05). Conclusão: O condicionamento ácido da dentina não influenciou a resistência de união imediata dos dois sistemas adesivos autocondicionantes de dois passos.

Objetivo: O objetivo desse estudo é avaliar o efeito a adição de salicilato de metila e óleo de silicone no tempo de presa, escoamento e espessura de película de um cimento a base de resina de salicilato e hidróxido de cálcio. Métodos: Um cimento experimental base constituído de 70% de uma resina de glicerol salicilato e 30% de hidróxido de cálcio teve sua viscosidade ajustada a partir da adição de salicilato de metila (SM) e/ou óleo de silicone (OS) em diferentes concentrações: 10% SM, 15% SM, 20% SM, 10% OS, 15% OS, 20% OS, 5% SM + 15% OS, 10% SM + 10%OS e 15% SM + 5% OS. Tempo de presa, escoamento e espessura de película dos cimentos foram aferidos conforme a ISO 6876. Resultados: O tempo de presa variou de 1,33h (20% SM) a 14,42h (10% OS), observando-se que a adição de salicilato de metila acelera a reação de presa e o acréscimo de óleo de silicone leva a um maior tempo de presa. Os maiores valores de escoamento e que atenderam aos 20mm mínimos requeridos pela ISO 6876, foram encontrados para os grupos 15% SM, 5% SM + 15% OS e 10% SM + 10% OS, chegando a 29,29±12,86mm. A espessura de película variou de 70,00±26,46 a 216,67±80,21µm, sendo o menor valor verificado para o grupo 5% SM + 15%. Conclusão: A adição de 5% de salicilato de metila e 15% de óleo de silicone produziu um cimento com tempo de presa, escoamento e espessura de película adequados para obturação de canais radiculares.

Abstract The effects of disinfection by microwave irradiation and immersion in peracetic acid on the physical-mechanical properties of a microwave-activated acrylic resin were evaluated. Specimens of acrylic resin were divided into a control group (specimens not disinfected) and 2 test groups subjected to one disinfection method: microwave irradiation at 850 W for 1 minute or immersion in 50 mL of 0.2% peracetic acid for 5 minutes. Specimens were submitted to Knoop hardness, flexural strength, flexural modulus, Izod impact, water sorption and solubility, glass transition temperature, and degree of conversion tests. Microwave disinfection significantly increased the mean Knoop hardness, Izod impact strength, water sorption, water solubility and glass transition temperature, whereas the flexural properties remained unaffected. Microwave disinfection increased the degree of conversion. Peracetic acid disinfection showed no changes in any properties. Both disinfection techniques did not adversely affect the evaluated properties.

Abstract The aim of this study was to evaluate the influence of different calcium phosphates (CaPs) on the physical, biological, and remineralizing properties of experimental resin-based sealants (RBSs). Triethylene-glycol dimethacrylate (90wt%) and bisphenol A-glycidyl methacrylate (10wt%) were used to produce resin-based sealants. Hydroxyapatite (SHAp), α-tricalcium phosphate (Sα-TCP) and octacalcium phosphate (SOCP) were added to the sealants in a 10wt% concentration. One group without CaPs was used as the control group (SCG). The degree of conversion (DC) was assessed with Fourier-transformed infrared spectroscopy, whereas cytotoxicity was tested with the HaCaT keratinocyte cell line. The ultimate tensile strength (UTS) was used to assess the mechanical strength of the experimental RBSs. Sealed enamel was used for colorimetric assay. Mineral deposition was assessed with Raman spectroscopy after 7, 14, and 28 days of sample immersion in artificial saliva. Scanning electron microscopy was used to analyze the surface morphology after 28 days of immersion. The addition of 10wt% of fillers significantly reduced the DC of sealants. SOCP groups showed reduced cell viability. Higher UTS was found for Sα-TCP and SHAp. The color analysis showed that SGC and demineralized teeth presented higher mismatches with the sound tissue. Mineral deposition was observed for SHAp and Sα-TCP after 7 days, with increased phosphate content and mineral deposits for SHAp after 28 days. RBS with the addition of 10% HAp promoted increased mineralization in vitro after 28 days, and did not affect cell viability, DC, mechanical properties, or RBS color in the enamel.

Objective: The aim of the present study was to evaluate the influence, of immersion in different disinfectant solutions, on microhardness and surface roughness of a heat-cured acrylic resin. Methods: Specimens were immersed in distilled water, commercial vinegar for domestic use, sodium hypochlorite and hydrogen peroxide, for 150 hours or 300 hours (n=10). After periods of immersion, Knoop microhardness and surface roughness were evaluated using a microhardness tester and a roughness tester, respectively. The data were analyzed using two-way ANOVA and Holm-Sidak, at a level of significance of 5%. Results: The microhardness values ranged from 16.90 ± 0.33 to 17.80 ± 0.51 and roughness values from 0.05 ± 0.01 to 0.08 ± 0.02. There is no difference in microhardness and roughness between groups and times (p>0.05). Conclusion: Within the limitations of this study, it is possible to conclude that vinegar and hydrogen peroxide, as alternative disinfectant solutions for acrylic resin devices, did not promote deleterious effects on microhardness and polishing of a heat-cured acrylic resin used for the fabrication of prostheses, neither in the medium term nor the long term.

Objective: To determine the influence of niobium pentoxide (Nb2O5) addition on the physical and chemical properties of glass ionomer cements (GICs). Materials and methods: Five, 10 or 20 wt.% of Nb2O5 were incorporated into commercial GICs (Maxxion R, Vitro Molar, Vitro Fil R) and one group of each GIC remained without Nb2O5 (control groups). The GICs were evaluated by Knoop hardness, compressive strength, acid erosion, particle size and radiopacity. Data were analyzed by two-way ANOVA followed by Tukey's test. Results: The addition of 10% and 20% reduced the microhardness of two GICs (p .05). Nb2O5 did not influence Maxxion R and Vitro Fil R regarding the acid erosion test (p > .05). Vitro Molar increased its acid erosion with 10% of Nb2O5 (p .05). Conclusion: The addition of 5 wt.% Nb2O5 did not affect the tested physical and chemical properties of the GICs and improved the radiopacity of one of the cements. These materials are therefore suitable for further testing of biomimetic remineralization properties.

Abstract This in situ study aimed to evaluate the antibacterial and anti-demineralization effects of an experimental orthodontic adhesive containing triazine and niobium phosphate bioglass (TAT) around brackets bonded to enamel surfaces. Sixteen volunteers were selected to use intra-oral devices with six metallic brackets bonded to enamel blocks. The experimental orthodontic adhesives were composed by 75% BisGMA and 25% TEGDMA containing 0% TAT and 20% TAT. Transbond XT adhesive (TXT) was used as a control group. Ten volunteers, mean age of 29 years, were included in the study. The six blocks of each volunteer were detached from the appliance after 7 and 14 days to evaluate mineral loss and bacterial growth including total bacteria, total Streptococci, Streptococci mutans, and Lactobacilli. Statistical analysis was performed using GLM model - univariate analysis of variance for microhardness and 2-way ANOVA for bacterial growth (p

Abstract This study aimed to evaluate the in situ degree of conversion, contact angle, and immediate and long-term bond strengths of a commercial primer and an experimental adhesive containing indomethacin- and triclosan-loaded nanocapsules (NCs). The indomethacin- and triclosan-loaded NCs, which promote anti-inflammatory and antibacterial effects through controlled release, were incorporated into the primer at a concentration of 2% and in the adhesive at concentrations of 1, 2, 5, and 10%. The in situ degree of conversion (DC, n=3) was evaluated by micro-Raman spectroscopy. The contact angle of the primer and adhesive on the dentin surface (n = 3) was determined by an optical tensiometer. For the microtensile bond strength µTBS test (12 teeth per group), stick-shaped specimens were tested under tensile stress immediately after preparation and after storage in water for 1 year. The data were analyzed using two-way ANOVA, three-way ANOVA and Tukey’s post hoc tests with α=0.05. The use of the NC-loaded adhesive resulted in a higher in situ degree of conversion. The DC values varied from 75.07 ± 8.83% to 96.18 ± 0.87%. The use of NCs in only the adhesive up to a concentration of 5% had no influence on the bond strength. The contact angle of the primer remained the same with and without NCs. The use of both the primer and adhesive with NCs (for all concentrations) resulted in a higher contact angle of the adhesive. The longitudinal μTBS was inversely proportional to the concentration of NCs in the adhesive system, exhibiting decreasing values for the groups with primer containing NCs and adhesives with increasing concentrations of NCs. Adhesives containing up to 5% of nanocapsules and primer with no NCs maintained the in situ degree of conversion, contact angle, and immediate and long-term bond strengths. Therefore, the NC-loaded adhesive can be an alternative method for combining the bond performance and therapeutic effects. The use of an adhesive with up to 5% nanocapsules containing indomethacin and triclosan and a primer with no nanocapsules maintained the long-term bond performance.

Self-adhesive, dual-polymerizing resin cements require no treatment to the prepared tooth surfaces before cementation. Aim: The aim of this study was to evaluate the influence of curing mode on bond strength (BS) of three cementing systems to bovine dentin. Methods: The buccal enamel surfaces of 50 bovine incisors were removed to expose dentin and to flat the surface. The teeth were divided into five groups (n=10), which consisted of two resin cements (Multilink and Clearfil SA Cement) that were tested in dual- (halogen light for 40 s) and self-cured modes, and a control (RelyX ARC). Two cylinders of resin cements (1.0 mm X 0.75 mm) were prepared on each bonded dentin surface. After 24h at 37oC, resin cylinders were subjected to micro-shear testing in a universal testing machine (4411/Instron - 0.5 mm/min). Data were statistically analyzed by two-way ANOVA, Tukey and Dunnett`s test (5%). Results: Multilink showed higher BS than those observed on Clearfil SA. Light-curing resulted in higher BS for both Multilink and Clearfil SA. When Multilink was light-cured, no significant difference on BS was demonstrated between it and RelyX ARC. Conclusions: The highest BS values were obtained in control group and light-cured Multilink resin cement.

Abstract The aim of this study was to develop an experimental adhesive with addition of [2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC) and to evaluate its mechanical and biological properties and its in vitro antibacterial activity. An experimental adhesive resin was formulated with Bis-GMA, TEGDMA, and HEMA. The antibacterial monomer was added at concentrations of 1%, 2.5%, and 5% (METAC groups). A group without METAC addition was used as control. The experimental adhesives were evaluated as to their antibacterial potential against Streptococcus mutans, degree of conversion, and softening in ethanol for 2 hours. The data were analyzed by one-way ANOVA, Tukey’s post-hoc test, and the paired Student’s t-test (significance level of 0.05). METAC showed antibacterial activity against S. mutans at all concentrations (p < 0.05). There was no statistical difference across METAC groups (p > 0.05). The 1%, 2.5%, and 5% groups yielded the highest mean values for degree of conversion (p < 0.05). The 1% group did not differ from the control group (p > 0.05). There was no statistical difference in baseline microhardness values (p > 0.05) and microhardness values after immersion in ethanol were lower than at baseline for all groups (p < 0.05). There was no statistical difference in the reduction of Knoop hardness number (KHN) after immersion in ethanol for any of the groups (p > 0.05). The results of the present study indicate that METAC is a promising antibacterial agent when added to an adhesive system.

The insufficient radiopacity of dental adhesives applied under composite restorations makes the radiographic diagnosis of recurrent caries challenging. Consequently, the misdiagnosis may lead to unnecessary replacement of restorations. The aims of this study were to formulate experimental dental adhesives containing cerium dioxide (CeO2) and investigate the effects of different loadings of CeO2 on their radiopacity and degree of conversion for the first time. CeO2 was characterized by X-ray diffraction analysis, Fourier transforms infrared spectroscopy, and laser diffraction for particle size analysis. Experimental dental adhesives were formulated with CeO2 as the inorganic filler with loadings ranging from 0.36 to 5.76 vol.%. The unfilled adhesive was used as a control. The studied adhesives were evaluated for dispersion of CeO2 in the polymerized samples, degree of conversion, and radiopacity. CeO2 presented a monoclinic crystalline phase, peaks related to Ce-O bonding, and an average particle size of around 16 µm. CeO2 was dispersed in the adhesive, and the addition of these particles increased the adhesives’ radiopacity (p < 0.05). There was a significant decrease in the degree of conversion with CeO2 loadings higher than 1.44 vol.%. However, all materials showed a similar degree of conversion in comparison to commercially available adhesives. CeO2 particles were investigated for the first time as a promising compound to improve the radiopacity of the dental adhesives.

The purpose of this study was to evaluate the influence of the internal standard peak on the measured degree of conversion (DC) for methacrylate-based resins analyzed by Fourier-transform infrared spectroscopy (FTIR). The influence of different baseline measurement methods was also determined. Different blends were prepared, mixing BisGMA/BisEMA and BisGMA/TEGDMA at proportions of 0% to 100%, in weight. Camphoroquinone and ethyl-4-dimethylamino-benzoate were used to permit the light activation of blends. Degree of conversion was evaluated using FTIR equipped with an attenuated total reflectance (ATR) device. Samples were dispensed onto ATR crystal and light activated for 40 s. The DC was calculated by relating the height of the peak 1637 cm-1 to the intensity of different internal standard peaks (1715, 1608, or 1582 cm-1), measured using two different baseline methods, before and after polymerization. Data were compared by ANOVA at 5% significance. The relationship between DC and monomer ratio was obtained by regression analysis. Double-bond conversion ranged from 32.75% to 78.50% for BisGMA/BisEMA blends, and from 32.75% to 76.22% for BisGMA/TEGDMA blends. For the BisGMA/BisEMA blends, the DC showed a linear association with the composition of the comonomer blends, independent of the internal standard peak and baseline method used. In contrast, the trends in DC for BisGMA/TEGDMA blends were different for each method of measurement. The internal standard peaks and measurement baseline should be taken into account when using FTIR to calculate the DC of methacrylate-based resins, especially comonomer blends containing a high degree of monomers that lack aromatic rings.

Objective: To verify the influence of radiopaque fillers on an epoxy resin-based sealer. Material and Methods: Experimental sealers were formulated by adding 20%, 40%, 60%, 80%, 100% and 120% of calcium tungstate, ytterbium trifluoride or barium sulphate by weight to an epoxy-resin-base. Setting time, flow, film thickness, radiopacity, sorption, solubility, pH and push-out bond strength were evaluated. Results: The setting time ranged from 373 to 612.66 min, the flow varied from 13.81±0.49 to 22.49±0.37 mm, and the film thickness ranged from 16.67±5.77 to 33.33±11.54 µm. The lowest pH was 5.47±0.53, and the highest was 6.99±0.03. Radiopacity varied from 0.38±0.04 to 2.57±0.21 mmAl and increased with the amount of filler. Calcium tungstate sealers had a higher sorption and solubility than other sealers. There was no significant difference in the push-out bond strength among the fillers at the 120% concentration. CONCLUSION: The inorganic fillers evaluated and their concentrations affect the physicochemical properties of an epoxy resin-based root canal sealer.

Introduction: The aim of this study was to evaluate the addition of bismuth subcarbonate with different concentrations regarding the rheological properties of an experimental epoxy-based root canal sealer. Materials and Methods: Endodontic sealers were prepared with epoxy resin-based sealer with bismuth subcarbonate additions of 20%, 40%, 60%, 80%, 100%, and 120%. Flow, film thickness, working time, setting time, dimensional change, sorption, solubility, and cytotoxicity were studied according to the ISO standards. Data were statistically analyzed by one-way ANOVA, and Tukey multiple comparisons were used, with a significance level of 5%. Results: The flow, working time, water sorption, and solubility significantly decreased and the film thickness and dimensional change increased with higher filler particle addition. There were no statistically significant differences for setting time and cytotoxicity between the filler particle proportions. Conclusion: Experimental resin-based sealer with bismuth subcarbonate addition up to 40% can be an alternative for root canal sealer.

Aim: To evaluate the dislocation resistance of the quartz fiber post/cement/dentin interface after different adhesion strategies. Methods: Forty bovine lower central incisors were selected and prepared with K-files using the step-back technique, and irrigated with 3 mL of distilled water preceding the use of each instrument. Prepared teeth were stored at 37ºC and 100% humidity for 7 days. The roots were prepared and randomized into 4 groups. The quartz fiber post was cemented with an adhesion strategy according to the following groups: GBisCem- BISCEM; GOneStep±C&B- One Step ± C&B; GAllBond±C&B- AllBond3 ± C&B; GAllBondSE±C&B- AllBondSE ±C&B with a quartz fiber post. Cross-sectional root slices of 0.7 mm were produced and stored for 24 h at 37° C before being submitted to push-out bond strength. Results: The mean and standard deviation values of dislocation resistance were GBisCem: 1.12 (± 0.23) MPa, GOneStep±C&B: 0.81 (± 0.31) MPa, GAllBond±C&B: 0.98 (± 0.14) MPa, and GAllBondSE±C&B: 1.57 (± 0.04) MPa. GAllBondSE±C&B showed significantly higher values of dislocation resistance than the other groups. Conclusions: Based on this study design, it may be concluded that adhesion strategies showed different results of quartz post dislocation resistance. Simplified adhesive system with sodium benzene sulphinate incorporation provided superior dislocation resistance.

The aim of this study was to evaluate the physical properties of irreversible hydrocolloid materials poured immediately and after different storage periods. Four alginates were tested: Color Change (Cavex); Hydrogum (Zhermack); Hydrogum 5 (Zhermack); and Hydro Print Premium (Coltene). Their physical properties, including the recovery from deformation (n = 3), compressive strength (n = 3), and detail reproduction and gypsum compatibility (n = 3), were analyzed according to ANSI/ADA specification no. 18. Specimens were stored at 23ºC and humidity and were then poured with gypsum immediately and after 1, 2, 3, 4, and 5 days. The data were analyzed by two-way analysis of variance (ANOVA) and Tukey's test at p < 0.05. All of the alginate impression materials tested exhibited detail reproduction and gypsum compatibility at all times. Hydro Print Premium and Hydrogum 5 showed recovery from deformation, as established by ANSI/ADA specification no. 18, after 5 days of storage. As the storage time increased, the compressive strength values also increased. Considering the properties of compounds' recovery from deformation, compressive strength, and detail reproduction and gypsum compatibility, irreversible hydrocolloids should be poured immediately.

OBJECTIVE: To evaluate the response of elastomeric ligatures in several colors for a 4 mm traction over time. METHODS: Morelli® elastomeric ligatures, were submitted to traction forces using two rods of circular cross section, until a 4 mm distance was reached, matching the approximate diameter of an upper central incisor bracket of the same manufacturer. The ligatures were kept in artificial saliva immersion at 37 ºC. Forces levels were measured immediately (0 h), 2, 4, 6, 8, 10, 12, 24, 48, 72, 96 hours, 1, 2, 3, 4 weeks and results were submitted to two-way repeated-measures ANOVA statistical analysis. RESULTS: The gray samples showed the higher initial values of tensile strength. The lowest values were presented by purple, light pink, green, black and red groups. The greater tensile strength instability was presented by red, black, silver, green and gray groups. The greater tensile strength stability was presented by deep pink, dark blue, blue, purple and light pink groups. CONCLUSION: Elastomeric ligatures do not present stable behavior when suffering traction forces over time and different colors display different behaviors. Deep pink, dark blue, blue, purple and light pink groups, displayed the most stable forces, suggesting that they should be used during the treatment to obtain constant forces.

The aim of the present study was to evaluate two dental curricula at a school of dentistry in southern Brazil. The study population included dentists trained in the last two classes of the institution's old curriculum (n = 98) and graduates of the first two classes of the new curriculum (n = 56). A questionnaire with open and closed questions was used for an overall evaluation of different aspects of the curricula, such as study methods, importance given to basic sciences, quality of theoretical and clinical guidance, perception about skills needed to perform different dental procedures, professional goals and an overall assessment. Students in the new curriculum reported more frequent use of the internet (69.6%) and scientific articles (50.0%). More importance was given to the basic sciences in the new curriculum. Graduates of the old curriculum alleged themselves to be more capable of both performing conventional (99%) and complex amalgam restorations (68.4%), as well as three-unit fixed prostheses (62.2%). Graduates of the new curriculum alleged higher capability with periodontal surgeries (48.2%), treatment of temporomandibular joint (TMJ) disorders (58.1%) and public health planning (78.6%). Regarding professional goals, the new curriculum was associated with an increase in the graduates' willingness to work in the public health system and to pursue an academic career. New curriculum graduates reported higher overall assessments regarding their educational, as well as theoretical and clinical, outcomes. A new curricular approach was associated with several changes from the perspective of the students.

The aim of this study was to evaluate the influence of applying 2% chlorhexidine for 30 seconds after phosphoric acid conditioning of dentin on the immediate and long-term bond strengths in deciduous teeth. The occlusal enamel was removed from 40 human sound deciduous molars, which were exfoliated by natural means, and the dentin was conditioned with 37% phosphoric acid for 15 seconds and washed with running water. The specimens were divided into two groups of 20 teeth. The test group received an application of 2% chlorhexidine for 30 seconds prior to a three-step etch-and-rinse adhesive system, whereas the control group received only the adhesive system. Three cylindrical restorations were made with a composite resin for each tooth. Ten teeth in each group were submitted to a microshear bond strength test after 24 hours, while the remaining teeth were stored in distilled water at 37 °C for 6 months before testing the microshear bond strength. The test group had a higher bond strength than did the control group after 6 months of storage. No statistical differences were found when groups with the same dentin treatment were compared at different times. Short applications of chlorhexidine at low concentrations prevent hybrid layer degradation and positively affect bond strength over time.

O risco de contaminação cruzada durante a tomada de impressão é uma preocupação do profissional, desse modo a utilização de substâncias desinfetantes deve fazer parte do seu protocolo diário de impressões. O glutaraldeído 2% e o hipoclorito de sódio 1% são substâncias que apesar de efetivas para desinfecção possuem problemas quanto à toxicidade, biodegradabilidade, estabilidade da impressão e corrosão. O ácido peracético tem sido utilizado para desinfecção de artigos hospitalares por ser atóxico e biodegradável, no entanto sua eficácia como desinfetante de alginato ainda não foi avaliada. Objetivo: Avaliar a eficácia do ácido peracético e do glutaraldeído na desinfecção do alginato contaminado com Staphylococcus aureus em função do tempo de imersão (10 e 5 min). Materiais e métodos: Os corpos de prova foram previamente contaminados com S. aureus e em seguida divididos em seis grupos de acordo com a substância desinfetante e o tempo de imersão. As amostras foram incubadas em 20 mL de caldo BHI estéril em estufa a 35± 2 ºC, sob agitação de 100 rpm, por 16 horas. Posteriormente as amostras do caldo de todos os tubos de ensaio foram semeadas para determinar a presença ou ausência de células viáveis. Resultados: Os resultados mostraram que os grupos controle e o lavado em água estéril apresentaram crescimento bacteriano. Conclusão: O ácido peracético foi igualmente eficaz ao glutaraldeído para desinfecção, do alginato contaminado com S. aureus, por imersão tanto no tempo de 10 quanto 5 minutos

A desinfecção de impressões é uma medida de biossegurança fundamental para evitar contaminação cruzada, pois durante a tomada de impressão, o alginato entra em contato com a microbiota oral do paciente e, após sua geleificação, carrega consigo saliva, microrganismos e, eventualmente, sangue na sua superfície e no seu interior. Objetivo: avaliar através da análise de sua ação bacteriostática e bactericida, a eficácia de uma solução de glutaraldeído 2% após receber sucessivas imersões de impressões de alginato, contaminadas. Materiais e métodos: Foram coletadas sete amostras do desinfetante em uso. A avaliação da ação bacteriostática, das amostras se deu pela presença de bactérias viáveis através do método de Contagem Padrão em Ágar. Para a avaliação da ação bactericida, placas foram inoculadas com Escherichia. coli, Pseudomonas aeruginosa, e Staphylococcus aureus. Poços com 0,9 cm de diâmetro, realizados no meio de cultura das placas, receberam alíquotas de 100L de glutaraldeído, de cada amostra. As placas foram mantidas entre 8-10C, por 16 horas para difusão do composto. Após as placas foram para estufa a 37C, por 24 horas. A atividade antibacteriana foi avaliada pela presença de zonas de inibição de crescimento bacteriano em torno dos poços onde o glutaraldeído foi colocado. Resultados: Os resultados mostram que não houve crescimento bacteriano em nenhuma amostra e que todas as placas inoculadas mostraram zona de inibição pela ação do glutaraldeído. Conclusão: O delineamento deste estudo permite concluir que pelo menos, 70 impressões de alginato podem ser desinfetadas em 3L de glutaraldeído 2%, durante 28 dias.

OBJECTIVE: To evaluate the influence of saliva contamination on shear bond strength and the bond failure pattern of 3 adhesive systems (Transbond XT, AdheSE and Xeno III) on orthodontic metallic brackets bonded to human enamel. MATERIAL AND METHODS: Seventy-two permanent human molars were cut longitudinally in a mesiodistal direction, producing seventy-two specimens randomly divided into six groups. Each system was tested under 2 different enamel conditions: no contamination and contaminated with saliva. In T, A and X groups, the adhesive systems were applied to the enamel surface in accordance with manufacturer's instructions. In TS, AS and XS groups, saliva was applied to enamel surface followed by adhesive system application. The samples were stored in distilled water at 37ºC for 24 h, and then tested for shear bond strength in a universal testing machine (Emic, DL 2000) running at a crosshead speed of 1 mm/min. After bond failure, the enamel surfaces were observed under an optical microscope at 40x magnification. RESULTS: The control and contaminated groups showed no significant difference in shear bond strength for the same adhesive system. However, shear bond strength of T group (17.03±4.91) was significantly higher than that of AS (8.58±1.73) and XS (10.39±4.06) groups (p

Atualmente, diversos cimentos são utilizados para cimentação de próteses fixas na prática clínica odontológica. Com o surgimento de novos materiais o cirurgião dentista assume um papel de fundamental importância na escolha do cimento empregado. O objetivo do presente estudo foi avaliar o uso de cimentos para prótese fixa por especialistas em prótese dentária que atuam no município de Porto Alegre, por meio de um questionário. Para isso, um questionário com 22 perguntas foi elaborado e aplicado a tais profissionais registrados no Conselho Regional de Odontologia. Dentre os 225 indivíduos elegíveis, 39 foram excluídos. Da amostra de 186 especialistas, 72 não foram entrevistados. Os 114 indivíduos entrevistados representaram uma taxa de resposta de 61,29%. O ano de graduação de 52% dos respondentes foi entre 1981 e 2000 e 63% concluíram o curso de pós-graduação após 1991. Para cimentação final de próteses fixas métalo-cerâmicas, 65% dos dentistas usam cimento de fosfato de zinco. Entretanto, para prótese fixas livres de metal, 57% utilizam cimento resinoso. Com o avanço da tecnologia em materiais reabilitadores, novos materiais e técnicas foram criados, no entanto, o cimento de fosfato de zinco segue como primeira escolha entre os especialistas para cimentação final de próteses métalo-cerâmicas.

O objetivo do presente estudo foi avaliar o coeficiente de resistência ao desgaste de diferentes materiais odontológicos submetidos ao ensaio de micro-abrasão através da metodologia de ball-crattering. Para isso foram avaliados diferentes materiais restauradores em comparação com o esmalte bovino. As amostras foram confeccionadas através de matrizes de nylon bipartida, com 7mm de diâmetro e 2mm de espessura em negativo e após, a resistência ao desgaste foi avaliada em um ensaio de micro abrasão (Ball cratering test) realizado em tribômetro modelo Calowear (CSEM Instruments Advanced Mechanical Surface Testing). Em cada corpo de prova foram feitas seis medições com variação no número de voltas realizadas pela esfera: 10, 20, 30, 40, 50 e 60 voltas. Após a realização das crateras o corpo de prova foi levado a um Zeiss Axiotech Vario Microscope com câmera SVGA acoplada onde foram fotografadas todas as crateras geradas e após, foram analisadas em UTHSCSA ImageTool for Windows versão 3.0, os valores de raio médio das marcas foram, então levados ao SigmaPlot versão 8.0 que através da correlação dos dados determinou o coeficiente de desgaste através de uma regressão linear. Para os corpos de esmalte bovino foi encontrado o coeficiente de desgaste de 3,83 X 10-14 m²/N, para resina composta micro híbrida 3,6542 x 10-14 m²/N, para amálgama de prata 2,06 x 10-12 m²/N e para resina acrílica autopolimerizável foi de 2,18 x 10-12 m²/N. Após a execução dos ensaios chega-se a conclusão que o esmalte bovino apresentou maior resistência e menor coeficiente de desgaste, seguido por resina composta, amálgama de prata e resina acrílica autopolimerizável.

O uso de dentes humanos para o ensino e pesquisa em Odontologia é uma prática freqüente. A implantação de Bancos de Dentes Humanos (BDH) em instituições de ensino é fundamental para viabilizar a manipulação segura para aprendizagem, pesquisa e inovações tecnológicas que façam uso de dentes humanos. Para que seu funcionamento seja adequado, a organização e a legalização do uso de dentes devem ser divulgados. Procedimentos relativos às etapas de arrecadação, limpeza e desinfecção, separação e armazenamento, cessão e/ou empréstimo e de biossegurança devem ser desenvolvidos, aprimorados e colocados ao alcance dos interessados. Este artigo tem como objetivo revisar a literatura acerca da importância do BDH em instituições de ensino e pesquisa assim como seus aspectos práticos, legais, técnicos e científicos.

Este estudo testou a hipótese nula de que o número de camadas de aplicação de um primer auto-condicionante pode não influenciar não resistência da interface adesiva resina/esmalte à microtração. Dentes bovinos foram niveladas, para expor os prismas de esmalte, utilizando-se lixa d´água #600. Os dentes foram divididos em dois grupos: FB 1 camada, FuturaBond (Voco) aplicado de acordo com as recomendações do fabricante por 30 s; e, FB 4 camadas, aplicadas quatro vezes, 30s cada. Foram então restaurados com a resina composta fotopolimerizável Polofil (Voco). Após 24 horas as amostras foram cortadas com um disco diamantado em baixa rotação sob abundante irrigação para obter palitos de aproximadamente 0,5 mm2 de área. Os palitos foram submetidos á microtração a uma velocidade de 1 mm/min. A resistência adesiva, em MPa, foi: FB 1 camada, 33.57 ±8.77 (18); FB 4 camadas: 33.57 ±8.77 (18). Esses valores, no teste t de student, não apresentaram diferença significativa (p=0.58). Nesse estudo, o número de camadas não interferiu nos valores de resistência de união da interface resina/esmalte.

The objective of this study was to evaluate the influence of temporary zinc oxide-eugenol cements (ZOEs) on the microtensile bond strength (ìTBS) of an all-in-one adhesive system to dentin. Buccal dentin surface of fifteen bovine incisors were exposed and polished with 600-grit SiC paper. Next, three groups were formed: Group 1 (G1), in which the dentin surface was covered with ZOE (TempCem); Group 2 (G2), in which the dentin surface was covered with temporary cement composed of zinc oxide and an aliphatic acid replacing eugenol (TempCem NE); Group 3 (G3) - no temporary cement was used. Each group was individually stored in distilled water at 37° C for 7 days, whereupon temporary cements were mechanically removed. All groups underwent the adhesive protocol with a simplified self-etching adhesive (One-UP Bond F). Four sticks per tooth were obtained, resulting in 20 sticks per group with a cross-sectional area of 0.5 mm2 . The ìTBS test was performed with a crosshead speed of 1mm/min. The failure pattern was analyzed by SEM. The data were submitted to one-way ANOVA, at p

Aim: To evaluate the influence of bismuth subsalicylate addition in different concentrations on theproperties ofan experimental epoxy-based root canal sealer. Methods: Bismuth subsalicylate in 20%, 40%, 60%, 80%, 100% and 120 wt% was added tothe sealer. Flow, film thickness, working time, setting time, dimensional change, sorption, solubility and cytotoxicity were evaluated according to ISO standard. Data were statistically analyzed by one-way ANOVA and Tukey’stest with a significance level of 5% for all tests. Results: The flow, working and setting times significantly decreased withincreasing particle concentration. The film thickness, dimensional change, water sorption and solubility values significantly increased with higher particle amount. The results for cytotoxicity showed no statistically significant differences among the particle proportions. Conclusions: The results suggest that the addition up to 80% wt of bismuth subsalicylate appears to be a promising filler particle to root canal sealer development.

Objetivos: o objetivo desse trabalho foi avaliar o grau de conversão (GC) de diferentes espessuras (1; 2; 3 e 4 mm) de uma resina adesiva translúcida de uso odontológico. Materiais e métodos: o GC de uma resina adesiva translúcida foi avaliado por meio de espectroscopia no infravermelho por transformada de Fourier (FTIR) acoplado a um dispositivo de refletância total atenuada (ATR). Foram utilizadas quatro matrizes de polivinilsiloxano de 1; 2; 3 ou 4 mm de espessura por 7 mm de diâmetro cada uma para conter o adesivo dispensado (n = 3) sobre o cristal de diamante do dispositivo de ATR. ANOVA de uma via e teste de comparações múltiplas de Student-Newman-Keuls foram utilizados com um nível de significância estatística de 5%. Resultados: espécimes de 1 mm de espessura apresentaram estatisticamente maiores valores de GC (62,19± 0,20) comparado aos demais grupos (p0,05), mas foram maiores que o grupo de 4mm (p>0,05). Conclusão: é necessária a padronização da espessura dos espécimes submetidos ao ensaio de avaliação de GC por FTIR-ATR.

Em uma primeira etapa deste trabalho, buscou-se desenvolver uma técnica de polimento químico de resinas acrílicas que utilizasse o forno de microondas LG Modelo MB (315m1- 1.000watts) para o aquecimento de líquidos para polimento. A potencia do forno de microondas e o tempo necessários para aquecer os líquidos para polimento ate uma temperatura de 81 ± 5°C — intervalo de temperatura equivalente ao obtido na polidora elétrica- foram 900 watts (90% da potencia máxima) e 90 segundos. A seguir, foram confeccionados 100 corpos-de prova, 50 amostras de resina acrílica quimicamente ativada e 50 de resina acrílica ativada por energia de microondas, os quais foram submetidos a cinco diferentes técnicas de polimento: 1) polimento mecânico- controle, 2) polimento químico com liquido para polimento em polidora elétrica, 3) polimento químico com monômero de resina acrílica em polidora elétrica, 4) polimento químico com liquido para polimento aquecido em forno de microondas, 5) polimento químico com monômero de resina acrílica aquecido em forno de microondas. Eles foram comparados, quanto a eficacia da técnica, usando como parâmetro a rugosidade superficial das resinas acrílicas. Para essa avaliação foi usado um rugosímetro SJ-201 (Mitotoyo - Japan). Os resultados foram submetidos a analise de variância e as medias comparadas pelo teste de Tukey (a = 1%). Os resultados mostraram que todas as técnicas de polimento geraram valores de rugosidade com diferença estatística significativa quando comparados com a técnica de polimento mecânico (controle), a qual apresentou valores de rugosidade superficial abaixo do limiar de Ra, estabelecido como 0,2 um. Não houve diferença estatisticamente significante entre as quatro técnicas de polimento químico.

Aim: To evaluate the long-term post push-out bond strength to dentin, water sorption, solubility and swelling of conventional and self-adhesive dual-cure resin cements. Methods: Forty-eight bovine roots were prepared for fiber post cementation with RelyX ARC and RelyX U100. According to resin cement and storage time (24 h and 6 months), 4 groups were assessed using the push-out test. Water sorption and solubility were performed according to ISO 4049:2009. The swelling coefficient was obtained using cement disks of each material immersed in distilled water until the swelling equilibrium was reached. The mass of dry and swelled polymer and solvent density were used to calculate the coefficient. Statistical data analysis was performed using Student’s t-test for water sorption, solubility and swelling coefficient and the Kruskal-Wallis and Dunn multiple comparison tests for push-out analysis with a significance level of 0.05. Results: The immediate bond strength was not significantly different between RelyX ARC (3.09 MPa) and RelyX U100 (3.78 MPa) (p>0.05). RelyX U100 showed higher (p0.05) between groups. The swelling coefficient of the RelyX U100 group was significantly higher than that of the RelyX ARC group (p

Aim: To evaluate the long-term bond strength, degree of conversion and resistance to degradation in ethanol of HEMA-containing and HEMA-free model adhesive resins of a three-step etch-andrinse adhesive system. Methods: The superficial dentin of 16 bovine incisor teeth was exposed, and the teeth were divided in two groups according to the HEMA concentration in the experimental adhesive (0% and 15%). In each tooth were made 6 cylindrical composite restorations. Half of the tooth restorations were submitted to microshear bond strength test after 24 h and the other half after 6 months. Degree of conversion of experimental resins was determined by Fourier transform infrared spectroscopy. Crosslink density was indirectly determined by the Knoop hardness of five specimens per group before and after immersion in ethanol for 6 h. Results: The group with 0% HEMA showed no difference in bond strength as compared to the group with 15% HEMA after 24 h or 6 months. There was no difference in degree of conversion and crosslink density between groups. Conclusions: HEMA content of the adhesive resin did not influence the bond strength to dentin, degree of conversion or resistance to degradation in ethanol.

O objetivo deste trabalho foi avaliar o efeito da substituição do eugenol pelo isoeugenol na formulação do cimento de óxido de zinco e eugenol, em relação às propriedades de tempo de presa e espessura de película, devido à comprovada genotoxicidade apresentada pelo eugenol. Utilizou-se o pó do cimento de óxido de zinco e eugenol (Endofill - Dentsply Herpo) e o isoeugenol (98%). Com base na especificação número 57 da Associação Dentária Americana (A.D.A.) foram avaliados o tempo de presa e a espessura de película. Para determinação do tempo de presa, foram confeccionados corpos de prova de diâmetro interno de 100 mm e espessura de 2 mm, que foram levados à estufa a 37°C. Com o auxílio de uma agulha de Gillmore com 100 g e diâmetro de 2 mm, foi determinado o tempo de presa do material. Foram determinados os seguintes tempos de presa: A - 1h e 08min; B - 1h e 10min; C - 1h e 13min. Para determinação da espessura de película, utilizou-se a proporção de 330 mg de óxido de zinco e 110 mg de isoeugenol colocada entre duas placas de vidro que tiveram a sua espessura medida por um micrômetro. O material espatulado foi colocado sobre uma das placas e coberto com a outra. Sobre as placas foi aplicada uma carga de 147 N por 10 minutos. Após este período, as placas com o cimento interposto foram retiradas e novamente foi medida a sua espessura. A diferença entre a primeira e a segunda medida resultou na espessura de película: A - 30 m; B - 26 m; C - 28 m. Com base nos resultados concluiu-se que, quanto à espessura de película, o material foi aprovado pela especificação que exige a espessura máxima de 50 um. Já quanto ao tempo de presa, este foi além dos 10% em relação ao proposto pelo fabricante, no entanto, como nas obturações de canal este tempo não é crítico, seria viável sugerir a substituição proposta considerando as propriedades analisadas.

Aim: The aim of this study was to evaluate the influence of acrylic resin immersion in different mouthwashes on hardness, roughness and color. Methods: Specimens of an orthodontic selfcured acrylic resin (Orto Clas®) were produced and immersed in five mouthwashes: Plax® Classic (Colgate®); Plax® alcohol-free (Colgate®); Listerine® (Johnson & Johnson®); Periogard® (Colgate®) and Periogard® alcohol-free (Colgate®). Nine different immersion times were studied: 1, 2, 4, 6, 8, 10, 12, 24 h and 7 days, totalizing 45 groups. The specimens were evaluated before and after immersion by Knoop microhardness (n=5), roughness in Ra parameter (n=5), and colorimetric analysis, CIElab (n=3). Results: All mouthwashes softened the acrylic resins after 7 days of immersion. PlaxÒ alcohol-free showed no statistically significant difference of softening between the immersion times. Listerine® showed softening after immersion at all times. Plax® alcohol-free and Listerine® showed significantly increased values of roughness after 12 h of immersion (p

O objetivo deste trabalho foi avaliar "in vitro" o efeito do cimento adesivo Panavia EX na microinfiltração de restaurações de amálgama. Trinta dentes humanos com cavidades classe V foram divididos em 3 grupos e restaurados da seguinte forma: no grupo A todas as cavidades foram restauradas apenas com amálgama; no grupo B uma camada de Panavia EX foi aplicada às paredes cavitárias antes da restauração e no grupo C, o esmalte do contorno da cavidade foi condicionado com ácido, as paredes da cavidade protegidas com Panavia EX e então restauradas com amálgama. Os dentes foram imersos numa solução de azul de metileno e os resultados indicaram que: a) todas as restaurações de amálgama sem Panavia EX mostraram infiltração severa e moderada; b) as restaurações forradas com Panavia EX tiveram reduzida infiltração quando comparadas com o controle (Grupo A); e, c) não houve influência do condicionamento ácido quanto à infiltração marginal.

Existem poucos dados sobre o conhecimento da população sobre saúde. Este estudo investiga o conhecimento em relação à saúde e ao uso de medicamentos e remédios por parte de pacientes ambulatoriais de uma Faculdade de Odontologia do Sul do Brasil. Para isso, foi usado um questionário que abordou questões relativas à saúde e ao uso e conhecimento de medicamentos. A amostra consistiu de 89 pacientes. A maioria deles (58,3%) considera que a origem das doenças que acometem a cavidade oral é de responsabilidade individual e/ou social. Mais da metade dos entrevistados (55,1%) relata seguir perfeitamente as orientações do prescritor. Menos da metade (44,9%) já usou medicamentos indicados por pessoa leiga. Apesar de estarem esperando por tratamento odontológico, 50,6% negaram ter problema de saúde. A maioria dos entrevistados (58,4%) não relata problemas em seguir uma prescrição. Entretanto, quando feitas questões induzidas, quase 80% da amostra apontaram dificuldades, como preço e efeitos adversos. Após análise dos dados observa-se a falta de conhecimento das pessoas em relação ao tema saúde, especialmente no que se refere a medicamentos.

Durante o processo de moldagem, o alginato é contaminado com saliva, placa e eventualmente com sangue, meios que podem conter microrganismos e, assim, constituem um risco de contaminação cruzada entre pacientes e profissionais da Odontologia. Sendo assim, faz-se necessária a adoção de um método de desinfecção eficaz. A proposta deste trabalho foi avaliar a eficácia antibacteriana das soluções de glutaraldeído (2%) e hipoclorito de sódio (2%) na desinfecção dos moldes de alginato, durante imersão de 10 min, comparando-as com a lavagem em água e moldagem controle. A avaliação se deu pela turvação do meio de cultura e confecção de lâminas para análise microscópica. Os resultados mostraram que dos 48 corpos de prova de alginato obtidos após moldagem de 12 pacientes, aqueles lavados em água por 10 s, ou incluídos diretamente no meio, apresentaram proliferação bacteriana, enquanto que os submetidos à desinfecção química não provocaram contaminação nos meios de cultura, comprovando a eficácia dos desinfetantes.

O objetivo desta pesquisa foi avaliar, in vitro, a influência do tipo de adesivo na resistência de união de “brackets” metálicos colados ao esmalte de dentes humanos. Trinta molares humanos extraídos foram incluídos em tubos de PVC e aleatoriamente divididos em três grupos (n=10): Grupo I – “bracket” colado com Transbond (3M/Unitek), Grupo II – “bracket” colado com AdheSE (Ivoclar/Vivadent) e Grupo III – “bracket” colado com Xeno III (Dentsply). O preparo da superfície de esmalte foi realizada profilaxia, seguido da aplicação dos adesivos conforme instruções dos fabricantes. Os “brackets” metálicos (Morelli®) foram colados na porção central de cada fragmento com resina fotoativada Transbond XT (3M/Unitek). Os corpos-de-prova foram armazenados em água destilada a 37ºC durante 24 horas. Em seguida, foram submetidos ao teste de cisalhamento em máquina de ensaio universal (EMIC, DL 2000), com velocidade de 1 mm/minuto e ao Índice de Adesivo Remanescente (IAR). A análise estatística (ANOVA/Tukey) demonstrou que o fator adesivo não influencia a resistência de união ao cisalhamento. Dessa forma, os adesivos autocondicionantes são uma boa alternativa para a colagem de “brackets” metálicos.

O objetivo deste trabalho foi avaliar a porosidade das resinas acrílicas de termo-polimerização em função do tempo decorrido entre a inclusão e a polimerização. Os resultados mostraram que a armazenagem da mistura por um período de até duas semanas pode ser considerado seguro quanto aos riscos de porosidade na resina acrílica desde que sejam observadas todas as recomendações e mantidos todos os cuidados requeridos por uma técnica correta de manipulação das resinas acrílicas de termo-polimerização.

ABSTRACT Introduction: There is a great variety of orthodontic brackets in the Brazilian market, and constantly evaluating them is critical for professionals to know their properties, so as to be able to choose which product best suits their clinical practice. Objectives: To evaluate the bond strength and the adhesive remnant index (ARI) of different brands of metal brackets. Material and Methods: A total of 105 bovine incisors were used, and brackets of different brands were bonded to teeth. Seven different bracket brands were tested (MorelliTM, American OrthodonticsTM, TP OrthodonticsTM, Abzil-3MTM, OrthometricTM, TecnidentTM and UNIDENTM). Twenty-four hours after bonding, shear bond strength test was performed; and after debonding, the ARI was determined by using an optical microscope at a 10-fold increase. Results: Mean shear bond strength values ranged from 3.845 ± 3.997 (MorelliTM) to 9.871 ± 5.106 MPa (TecnidentTM). The majority of the ARI index scores was 0 and 1. Conclusion: Among the evaluated brackets, the one with the lowest mean shear bond strength values was MorelliTM. General evaluation of groups indicated that a greater number of bond failure occurred at the enamel/adhesive interface.

ABSTRACT Orthodontic treatment with fixed brackets plays a major role on the formation of white spot lesions. Objective This study aimed to incorporate silver nanoparticle solutions (AgNP) in an orthodontic adhesive and evaluate its physicochemical and antimicrobial properties. Material and Methods Silver nanoparticle solutions were added to a commercial adhesive in different concentrations (w/w): 0%, 0.11%, 0.18%, and 0.33%. Shear bond strength (SBS) test was performed after bonding metal brackets to enamel. Raman spectroscopy was used to analyze in situ the degree of conversion (DC) of the adhesive layer. The surface free energy (SFE) was evaluated after the measurement of contact angles. Growth inhibition of Streptococcus mutans in liquid and solid media was determined by colony-forming unit count and inhibition halo, respectively. One-way ANOVA was performed for SBS, DC, SFE, and growth inhibition. Results The incorporation of AgNP solution decreased the SBS (p

Abstract The present study aimed to evaluate effects of different surface treatments and aging of composite cylinders on bond strength of composite resin repair. Thirty-two composite cylinders were produced and divided into four groups according to type of surface treatment and storage time of composite cylinder and repair. Cylinder surface of control group (Gcontrol) received no treatment before composite repair. Other groups were sandblasted with aluminum oxide (GAl2O3), followed by silane (GAl2O3sil) or adhesive (GAl2O3ad). Composite cylinders were stored in artificial saliva for either 24 hours or 1 year. Repairs were performed and stored in artificial saliva for 24 hours or 1 year and repair strength was evaluated using microtensile bond strength test. Data were submitted to Student’s t test, two-way ANOVA, and post hoc test for storage time and treatment (α = 0.05). Gcontrol group showed lower values of aging of composite cylinder and storage time of repair (24 hours or 1 year for both) compared with other groups (p < 0.05). GAl2O3ad and GAl2O3sil groups did not exhibit decreased microtensile bond strength with aged repairs (1 year; p > 0.05). Polymer degradation was significant for composite cylinders during the first year of storage in Gcontrol, GAl2O3, and GAl2O3ad groups (p < 0.05). In GAl2O3sil group, storage time of composite cylinders was not significant (p > 0.05). Aging of composite resin influenced bond strength of restoration repair for up to 1 year. Sandblasting with Al2O3, followed by application of silane layer, produced high bond strength after composite or repair aging.