Simplified ethanol wet-bonding technique: an alternative strategy for resin-dentin bonding in root canals.

The objective of this study was to evaluate the effect of the simplified ethanol wet-bonding technique on luting of posts to intraradicular dentin. The effect was assessed by push-out bond strength testing and confocal laser scanning microscopic analysis. Thirty endodontically treated roots were distributed into 3 groups (n = 10): water wet-bonding; stepwise ethanol wet-bonding; and simplified ethanol wet-bonding. After cementation of the posts, the roots were sectioned. Specimens were stored for 24 hours or 1 year before they were stressed to failure. Specimens from each group were processed for microscopic analysis. Data were analyzed using a 2-way analysis of variance and the Tukey test (α = 0.05). Statistically significant differences in push-out bond strength values were observed between the technique groups (P < 0.001) and between the storage periods (P = 0.009). The bond strength results in the group bonded using the simplified ethanol wet-dehydration approach did not differ from those in the group bonded using the stepwise ethanol technique at either storage time interval (P > 0.05). From 24 hours to 1 year, there was a similar decrease in bond strength for specimens prepared with the simplified and stepwise techniques. The microscopic results confirmed that ethanol wet-bonding technique improved the quality of the interface. The simplified ethanol wet-dehydration protocol achieved bond strengths and stability over time that were similar to those obtained with the stepwise ethanol technique and may be considered an alternative strategy to accomplish resin cement-root dentin bonding.

Key aspects related to implementation of risk stratification in health care systems-the ASSEHS study.

BACKGROUND: The lack of proven efficacy of new healthcare interventions represents a problem for health systems globally. It is partly related to suboptimal implementation processes, leading to poor adoption of new interventions. Activation of Stratification Strategies and Results of the interventions on frail patients of Healthcare Services (ASSEHS) EU project (N° 2013 12 04) aims to study current existing health Risk Stratification (RS) strategies and tools on frail elderly patients. This paper aims at identifying variables that make the implementation of population RS tools feasible in different healthcare services. METHODS: Two different methods have been used to identify the key elements in stratification implementation; i) a Scoping Review, in order to search and gather scientific evidence and ii) Semi-structured interviews with six key experts that had been actively involved in the design and/or implementation of RS strategies. It aims to focus the implementation construct on real-life contextual understandings, multi-level perspectives, and cultural influences. RESULTS: A Feasibility Framework has been drawn. Two dimensions impact the feasibility of RS: (i) Planning, deployment and change management and (ii) Care intervention. The former comprises communication, training and mutual learning, multidisciplinarity of the team, clinicians' engagement, operational plan and ICT display and functionalities. The latter includes case finding and selection of the target population, pathway definition and quality improvement process. CONCLUSIONS: The Feasibility Framework provides a list of key elements that should be considered for an effective implementation of population risk stratification interventions. It helps to identify, plan and consider relevant elements to ensure a proper RS implementation.

Nanoleakage of fiber posts luted with different adhesive strategies and the effect of chlorhexidine on the interface of dentin and self-adhesive cements.

The aim of this in vitro study was to evaluate the nanoleakage of fiber posts luted using different adhesive strategies and to investigate the effect of 2% chlorhexidine (CHX) on nanoleakage at the resin-dentin interfaces of self-adhesive cements. The self-adhesive and etch-and-rinse adhesive groups tested demonstrated similar results with regard to nanoleakage. Pretreatment with CHX promoted an adequate seal at the resin-dentin interface for self-adhesive cements.

Influence of photo-curing distance on bond strength and nanoleakage of self-etching adhesive bonds to enamel and dentin.

OBJECTIVES: To assess the influence of light-curing unit tip distance on the microtensile bond strength (µTBS) and nanoleakage of self-etching adhesives to enamel and dentin. MATERIALS AND METHODS: Flat buccal surfaces were prepared on 198 bovine incisors. The teeth were randomly assigned into nine groups for µTBS (n = 8) and nanoleakage (n = 3) testing according to the adhesive system (Clearfil Protect Bond, Clearfil Tri-S Bond or One Up Bond F Plus) and distance from the light-curing tip (0, 3 or 6 mm). The bonded samples were tested in tension (0.5 mm/min) and nanoleakage was analyzed using SEM. RESULTS: Clearfil Protect Bond exhibited the highest tensile strength on both enamel and dentin. Leakage was higher in samples exposed at a distance of 6 mm on enamel and 0 mm on dentin. One Up Bond F Plus experienced the greatest amount of nanoleakage on both substrates. CONCLUSIONS: Light-curing unit distance did not influence the µTBS of the adhesives, but nanoleakage increased on enamel samples when photoactivation occurred at a distance of 6 mm.

Color stability and polymerization behavior of direct esthetic restorations.

OBJECTIVES: The current study evaluated the effect of accelerated artificial aging (AAA) on the color stability (CS) and degree of conversion (DC) of nanofilled and nanohybrid resin composites associated to different adhesive systems in direct esthetic restorations. MATERIAL AND METHODS: Eighty bovine incisors were used to obtained dentin blocks (4 × 4 × 1 mm). The restorative systems were bonded to the blocks and photoactivated according to the manufacturer's instructions. Three adhesive systems were used: Adper Scotchbond Multi-Purpose (conventional of three steps), Tetric N-Bond (conventional of two steps) and ClearFill SE Bond (self-etching). Also, two composites were used: Filtek Z350 XT (nanofilled) and IPS Empress Direct (nanohybrid). The restorations were made using a silicone mold placed on top of the prepared dentin blocks (N = 10). CS was measured after 300 hours of AAA by means of ultraviolet light using a spectrophotometer and CIE L*a*b* parameters on the top surface of the composite and at the bonded interface. The DC was performed using Fourier transform infrared spectroscopy (N = 10). Data were analyzed using two-way analysis of variance and Tukey's test (α = 0.05). RESULTS: The adhesive systems had no significant influence on the color stability (ΔE) of either the restoration surface (α = 0.90) or the bonded interface (α = 0.78). However, composite influenced the color as measured by ΔE and isolated coordinates (α < 0.001). The nanohybrid composite showed increased DC values (67%) compared with the nanofilled (61%) with statistically significant differences (α < 0.001). CONCLUSIONS: The adhesive system did not affect the final color of direct esthetic restorations. The nanohybrid composite demonstrated a higher DC and increased color stability after AAA compared to the nanofilled composite. CLINICAL SIGNIFICANCE: The long-term color stability of composite restorations is a critical aspect of esthetic restorative procedures. Optimal Polymerization behavior of resin composite as indicated by the degree of conversion also influence on the color stability after artificial aging of composite restorations.

Minimally invasive cosmetic dentistry: smile reconstruction using direct resin bonding.

Discrepancies in tooth size and shape can interfere with smile harmony. Composite resin can be used to improve the esthetics of the smile at a low cost while offering good clinical performance. This article presents an approach for restoring and correcting functional, anatomic, and esthetic discrepancies with minimal intervention, using composites and a direct adhesive technique. This conservative restorative procedure provided the patient with maximum personal esthetic satisfaction.

Influence of remaining coronal structure and of the marginal design on the fracture strength of roots restored with cast post and core.

OBJECTIVE: The purpose of this study was to evaluate the fracture strength of roots that were prosthetically restored with cast post and core with or without any remaining coronal structure and with different finish lines. MATERIALS AND METHODS: Sixty bovine incisors were sectioned below the cementoenamel junction, endodontically treated and randomly divided into six experimental groups (n = 10) containing teeth with or without any remaining coronal structure and with a beveled shoulder, a chanfered or a shoulder finish line design. The cast post and core were luted with dual-cured resin cement. The metal crowns were cemented with zinc phosphate cement. The specimens were subjected to a tangential compressive load (135° angle) at a crosshead speed of 0.5 mm/min until failure, using a universal testing machine. The fracture strength data were analyzed using the ANOVA and LSMeans (least square means) tests (α = 0.05). RESULTS: The data indicated that the teeth with 2 mm of remaining coronal structure showed the highest fracture strength values when compared with the teeth without any remaining structure (p < 0.05). As to the different finish line designs, the highest fracture strength values were obtained for the beveled shoulder, followed by the chanfered and then by the shoulder designs (p < 0.05). CONCLUSIONS: It may be concluded that, to increase fracture strength, a beveled shoulder and 2 mm of remaining coronal structure are the ideal conditions.

Knoop hardness and effectiveness of dual-cured luting systems and flowable resin to bond leucite-reinforced ceramic to enamel.

PURPOSE: The aim of this study was to evaluate the Knoop microhardness and microshear bond strength (MSBS) of dual-cured luting systems and flowable resin bonded to leucite-reinforced ceramics and enamel. MATERIALS AND METHODS: Eighty bovine incisors were randomly divided into four groups per test (microhardness and microshear; n = 10) according to the bonding procedure: Excite DSC/Variolink, Clearfil SE Bond/Panavia F, Adper Scotchbond Multi-Purpose Plus/RelyX ARC, and Adper Single Bond 2/Filtek Z350 Flow. For the KHN measurement, the cement was applied on the enamel surface and light-cured through a ceramic disk (5 mm diameter × 1.2 mm thick). Five indentations were performed in each specimen and measured at HMV-2. For the microshear test, two cylinders of a leucite-reinforced ceramic (1 mm diameter × 2 mm height) were bonded to the enamel substrate in accordance with the bonding procedures previously established. One cylinder was tested 24 hours after cementation, and the other was subjected to thermocycling (2000 cycles) and then submitted to an MSBS test. The data from the hardness and bond strength tests were subjected to one- and two-way repeated-measures analysis of variance (ANOVA), respectively, and to Tukey's test (α= 0.05). RESULTS: Scotchbond/RelyX ARC presented higher values of bond strength, while Single Bond/Z350 Flow showed lower values. The thermocycling promoted a reduction in the bond strength values for all groups. Panavia F presented higher values of KHN, and the flowable resin presented the lowest. RelyX ARC and Variolink presented intermediate values on hardness evaluation. CONCLUSIONS: For ceramic cementation, dual-cured resin luting systems promoted more reliable bonding and microhardness values than the flowable resin.

Influence of the LED curing source and selective enamel etching on dentin bond strength of self-etch adhesives in class I composite restorations.

The aim of this study was to evaluate the influence of the LED curing unit and selective enamel etching on dentin microtensile bond strength (µTBS) for self-etch adhesives in class I composite restorations. On 96 human molars, box-shaped class I cavities were made maintaining enamel margins. Self-etch adhesives (Clearfil SE - CSE and Clearfil S(3) - S3) were used to bond a microhybrid composite. Before adhesive application, half of the teeth were enamel acid-etched and the other half was not. Adhesives and composites were cured with the following light curing units (LCUs): one polywave (UltraLume 5 - UL) and two single-peak (FlashLite 1401 - FL and Radii Cal - RD) LEDs. The specimens were then submitted to thermomechanical aging and longitudinally sectioned to obtain bonded sticks (0.9 mm(2)) to be tested in tension at 0.5 mm/min. The failure mode was then recorded. The µTBS data were submitted to a three-way ANOVA and Tukey's (α = 0.05). For S3, the selective enamel-etching provided lower µTBS values (20.7 ± 2.7) compared to the non-etched specimens (26.7 ± 2.2). UL yielded higher µTBS values (24.1 ± 3.2) in comparison to the photoactivation approach with FL (18.8 ±3.9) and RD (19.9 ±1.8) for CSE. The two-step CSE was not influenced by the enamel etching (p ≥ 0.05). Enamel acid etching in class I composite restorations affects the dentin µTBS of the one-step self-etch adhesive Clearfil S(3), with no alterations for Clearfil SE bond strength. The polywave LED promoted better bond strength for the two-step adhesive compared to the single-peak ones.

The effect of curing light and chemical catalyst on the degree of conversion of two dual cured resin luting cements.

The aim of this study was to evaluate the influence of different curing lights and chemical catalysts on the degree of conversion of resin luting cements. A total of 60 disk-shaped specimens of RelyX ARC or Panavia F of diameter 5 mm and thickness 0.5 mm were prepared and the respective chemical catalyst (Scotchbond Multi-Purpose Plus or ED Primer) was added. The specimens were light-cured using different curing units (an argon ion laser, an LED or a quartz-tungsten-halogen light) through shade A2 composite disks of diameter 10 mm and thickness 2 mm. After 24 h of dry storage at 37°C, the degree of conversion of the resin luting cements was measured by Fourier-transformed infrared spectroscopy. For statistical analysis, ANOVA and the Tukey test were used, with p ≤ 0.05. Panavia F when used without catalyst and cured using the LED or the argon ion laser showed degree of conversion values significantly lower than RelyX ARC, with and without catalyst, and cured with any of the light sources. Therefore, the degree of conversion of Panavia F with ED Primer cured with the quartz-tungsten-halogen light was significantly different from that of RelyX ARC regardless of the use of the chemical catalyst and light curing source. In conclusion, RelyX ARC can be cured satisfactorily with the argon ion laser, LED or quartz-tungsten-halogen light with or without a chemical catalyst. To obtain a satisfactory degree of conversion, Panavia F luting cement should be used with ED Primer and cured with halogen light.

Influence of the volume of restorative material on the concentration of stresses in the restorative interface.

BACKGROUND: To evaluate the microtensile strength in the adhesive interface depending on the volume of the composite resin used to restore class I cavities. MATERIAL AND METHODS: Forty-eight human third molars received a standardized class I cavity preparation and they were separated into six experimental groups: G1 - single-bottle adhesive system; G2 - bonding system with load; G3 - single-bottle adhesive associated with low-viscosity composite resin; G4 - loaded adhesive associated with low-viscosity composite; G5 - resin-modified glass ionomer associated with single-bottle adhesive; and G6 - resin-modified glass ionomer associated with loaded adhesive. All cavities were restored with a universal restorative composite. After completing the restorations, the samples were stored for seven days in a stove (37°C) and the microtensile bond strength was evaluated by producing slices and applying axial loading in an Instron universal testing machine at a speed of 0.5 mm/min. The thickness of the intermediate layer formed on the cavity floor to verify the relationship between the volume of restorative composite and the concentration of stresses in the buccal wall. With the data obtained in the microtensile strength test, an Analysis of Variance (ANOVA) was performed entirely at random. RESULTS: Duncan's test showed that group 4 (Filtek Flow/Optibond Solo Plus) obtained the highest mean of microtensile strength with no statistically significant difference to groups 3 (Filtek Flow/Single Bond), 5 (Vitremer/Single Bond), and 6 (Vitremer/Optibond Solo Plus). It also showed a statistically significant difference to groups 2 (Optibond Solo Plus) and 1 (Single Bond), with no statistical difference between the other groups studied. CONCLUSIONS: The highest mean of microtensile strength was obtained when the volume of the restorative material decreased through the interposition between the material and the adhesive system of a base with low elasticity modulus. Key words:Adhesion, microtensile, composite resin.

Milk and Dairy Products Intake Is Related to Cognitive Impairment at Baseline in Predimed Plus Trial.

SCOPE: To examine the association between milk and dairy products intake and the prevalence of cognitive decline among Spanish individuals at high cardiovascular risk. METHODS AND RESULTS: Cross-sectional analyses are performed on baseline data from 6744 adults (aged 55-75 years old). Intake of milk and dairy products is estimated using a food frequency questionnaire grouped into quartiles. The risk of developing cognitive impairment is based on the Mini-Mental State Examination (MMSE). A higher prevalence of cognitive decline was found in subjects who consumed more grams. Patients with worse MMSE score (10-24) consumed a mean of 395.14 ± 12.21 g, while patients with better MMSE score (27-30) consumed a mean of 341.23 ± 2.73 g (p < 0.05). Those subjects with the lower milk consumption (<220 g/day) had a higher MMSE score (28.35 ± 0.045). Higher intake of fermented dairy products was observed in participants with a lower MMSE score (OR 1.340, p = 0.003). A positive correlation was found between the consumption of whole milk and the MMSE score (r = 0.066, p < 0.001). CONCLUSIONS: These findings suggest that greater consumption of milk and dairy products could be associated with greater cognitive decline according to MMSE. Conversely, consumption of whole-fat milk could be linked with less cognitive impairment in the cross-sectional study.

Effect of different adhesive strategies on the microtensile bond strength of dentin to indirect resin-based composite.

BACKGROUND: To evaluate the microtensile bond strength of indirect resin composite bonded to dentin using five different adhesives strategies. MATERIAL AND METHODS: Forty specimens (Solidex) were produced and randomly into five groups with different adhesives strategies: (G1)- Single Bond Universal + etch + silane + RelyX Ultimate, (G2)- Single Bond Universal + silane + RelyX Ultimate, (G3)- Single Bond Universal + etch + RelyX Ultimate, (G4)- Single Bond Universal + RelyX Ultimate, and (G5)-Scotchbond Multi-purpose + RelyX ARC. After cementation the specimens were stored in 100% humidity for 24hours at 37°C. The specimens were sectioned perpendicular to the adhesive interface to obtain beams and submitted to microtensile test. Microtensile values were expressed in MPa and analyzed by one-way ANOVA and multiple comparison Tukey tests (α=0.05). RESULTS: The mean bond strength in MPa groups were: G1=11,48, G2=14,15, G3=16,95, G4=17,03 and G5=16,80. Statistical analysis showed that the bond strength values were not significantly affected by the different adhesive strategies. CONCLUSIONS: Cementation of dentin to indirect resin composite cannot be significantly affected by different adhesive strategies used. The specimens treated with silane, etch associated with Single bond universal did not increase bond strength values. Key words:Adhesives, dental cements, dentin.

Effects of desensitizing products on the reduction of pain sensitivity caused by in-office tooth bleaching: a 24-week follow-up.

OBJECTIVE: To clinically assess the effect of desensitizing gels and dentifrices on the reduction in pain sensitivity and color variation during tooth bleaching. METHODOLOGY: A total of 108 volunteers were randomly separated into the following groups of n=12: GT/S-glycerine and thickener/sucralose; NF/S-potassium nitrate and sodium fluoride/sucralose; NA/S-potassium nitrate and arginine/sucralose; GT/AC-glycerine and thickener/arginine and calcium carbonate; NF/AC-potassium nitrate and sodium fluoride/arginine and calcium carbonate; NA/AC-potassium nitrate and arginine/arginine and calcium carbonate; GT/PN-glycerine and thickener/potassium nitrate; NF/PN-potassium nitrate and sodium fluoride/potassium nitrate; and NA/PN-potassium nitrate and arginine/potassium nitrate. Sensitivity was assessed with the numerical analogue scale, and color variation (ΔE) was measured with a spectrophotometer. The sensitivity values obtained were subjected to a multivariate analysis of variance (MANOVA) and color variation values were subjected to a randomized analysis of variance (p<0.05). RESULTS: The NF/AC, NA/AC, NF/PN, and NA/PN groups presented lower sensitivity values and reduced sensitivity compared to those of the other groups throughout the clinical sessions. None of the groups showed sensitivity at the 24-week assessment. Statistically, no significant difference were observed in the color values among the groups four weeks after the beginning of bleaching (p=0.074). Additionally, the color assessment of all groups was statistically similar four weeks (p=0.084) and 24 weeks (p=0.118) after the beginning. CONCLUSION: Our results indicate that adding NF/S, NA/S, NF/AC, and NA/AC desensitizers to tooth bleaching protocols reduces pain sensitivity without affecting its effectiveness.

Effect of alternative solvent evaporation techniques on mechanical properties of primer-adhesive mixtures.

This study evaluated the influence of the mode and time of solvent evaporation on the tensile strength (TS), flexural strength (FS) and elastic modulus (EM) of two adhesive systems: Scotchbond Multipurpose (SBMP) and Clearfil SE (CSEB). For this purpose, rectangular samples (2x1x7 mm) were prepared with 10 µL of primer and the solvents were evaporated with air spray at (23±1) ºC, (40±1) ºC and negative control (without spray). For each temperature, the times of 5, 20, 30, and 60 seconds were investigated. The statistical results showed that evaporation at 40±1ºC resulted in better EM for the two adhesives tested and all the evaporation times evaluated. However, there were no significant differences between the times and modes of evaporation for TS. The results of this study indicate that evaporation at a temperature of (40±1) °C could improve the elastic modulus of both adhesives tested, regardless of the evaporating time.

Este estudo avaliou a influência do modo e do tempo de evaporação do solvente na resistência à tração (RT), resistência à flexão (RF) e módulo de elasticidade (MR) de dois sistemas adesivos: Scotchbond Multipurpose (SBMP) e Clearfil SE (CSEB). Para isso, amostras retangulares (2x1x7 mm) foram preparadas com 10 µL de primer e os solventes foram evaporados com aerossol a (23±1) ºC, (40±1) ºC e controle negativo (sem aerossol). Para cada temperatura, foram avaliados os tempos de 5, 20, 30 e 60 segundos. Os resultados estatísticos mostraram que a evaporação a (40±1) ºC resultou em melhor MR para os dois adesivos testados e todos os tempos de evaporação avaliados. No entanto, não houve diferenças significativas entre os tempos e modos de evaporação na RT. Os resultados deste estudo indicam que a evaporação a uma temperatura de (40±1) °C poderia melhorar o módulo de elasticidade de ambos os adesivos testados, independentemente do tempo de evaporação.

Association Between Lifestyle and Hypertriglyceridemic Waist Phenotype in the PREDIMED-Plus Study.

OBJECTIVE: The hypertriglyceridemic waist (HTGW) phenotype is characterized by abdominal obesity and high levels of triglycerides. In a cross-sectional assessment of PREDIMED-Plus trial participants at baseline, HTGW phenotype prevalence was evaluated, associated risk factors were analyzed, and the lifestyle of individuals with metabolic syndrome and HTGW was examined. METHODS: A total of 6,874 individuals aged 55 to 75 with BMI ≥ 27 and < 40 kg/m2 were included and classified by presence (HTGW+ ) or absence (HTGW- ) of HTGW (waist circumference: men ≥ 102 cm, women ≥ 88 cm; fasting plasma triglycerides ≥ 150 mg/dL). Analytical parameters and lifestyle (energy intake and expenditure) were analyzed. RESULTS: A total of 38.2% of the sample met HTGW+ criteria. HTGW+ individuals tended to be younger, have a greater degree of obesity, be sedentary, and be tobacco users. They had higher peripheral glucose, total cholesterol, and low-density lipoprotein cholesterol levels; had lower high-density lipoprotein cholesterol levels; and had increased prevalence of type 2 diabetes mellitus. Mediterranean diet (MedDiet) adherence and physical activity were greater in HTGW- patients. Age, BMI, tobacco use, total energy expenditure, hypertension, type 2 diabetes mellitus, and MedDiet adherence were associated with HTGW+ . CONCLUSIONS: HTGW is a highly prevalent phenotype in this population associated with younger age, higher BMI, tobacco use, and decreased MedDiet adherence. HTGW- individuals were more physically active with greater total physical activity, and fewer had hypertension.

Effects of desensitizing dentifrices on the reduction of pain sensitivity caused by in-office dental whitening: a double-blind controlled clinical study.

Objective: The purpose of this study was to clinically evaluate the influence of desensitizing dentifrices applied through a plastic tray on reducing the pain sensitivity and color variation caused by in-office dental whitening and to evaluate differences among such dentifrices through a controlled double-blind clinical study. Materials and methods: A prospective study was conducted with 48 individuals between 18 and 30 years without gender distinction. For the dental whitening, 35% hydrogen peroxide was used in three clinical sessions. After each whitening session, the volunteers used a plastic tray containing one of the dentifrices (sucralose- S, sodium fluoride - SF, arginine and calcium carbonate - ACC, and 5% potassium nitrate - PN) for 4 hrs during the night. The evaluation of the sensitivity associated with the use of the plastic tray in each whitening session was performed using the analog numerical scale with scores from 0 to 10. The color variation (ΔE) was determined with a spectrophotometer. The pain sensitivity data were submitted to the multivariate analysis of variance with repeated measurements and a Lambda Wilks test (p<0.05). To analyze the color variation, a one-way ANOVA was applied (p<0.05). Results: The ACC and 5% NP groups showed a reduction in sensitivity in relation to the other groups (p<0.05). There was a reduction in sensitivity after placement of the tray with dentifrice. The color evaluation associated with the dentifrice showed no difference (p=0.9186). Conclusion: The use of desensitizing dentifrices with ACC or 5% NP in a plastic tray was effective for the reduction of pain sensitivity, and the use of a desensitizing dentifrice did not decrease the effectiveness of whitening.

Desensitizing Agent Previously Applied During In-Office Bleaching: A Double-Blind Randomized Clinical Trial

Abstract Objective: To compare the clinical effect of two desensitizing agents used before the application of a bleaching gel based on 35% hydrogen peroxide (HP). Material and Methods: 30 patients were selected, and two desensitizing agents with different mechanisms of action were applied: Fluorine Neutral 2% (FN), which acts by blocking dentinal canaliculi while Potassium Nitrate 5% with 2% Sodium Fluoride (PN/SF) that acts in nerve transmission and blockade. Desensitizers were used before the application of 35% HP. For whitening, three clinical sessions were performed, with an interval of seven days, with three applications of the bleaching gel for 15 minutes, totaling 45 minutes/session. Tooth sensitivity (TS) was assessed with the numerical analog scale, and a spectrophotometer was used to obtain the color variation (ΔE). ΔE were submitted to ANOVA and Tukey test (p<0.05), and TS data were submitted to a two-way ANOVA analysis. Results: For sensitivity experience, the Tukey test indicated differences between PN/SF and the placebo I, but there was no statistically significant difference between FN and the placebo II. The TS was lower when the desensitizing gel was used during the bleaching procedure compared to after treatment, regardless of the desensitizing agents. Conclusion: PN/SF before in-office tooth bleaching can reduce TS intensity, and the use of desensitizing gel before bleaching did not affect the bleaching efficacy.

Evaluation of degree of conversion and the effect of thermal aging on the color stability of resin cements and flowable composite.

PURPOSE: The aim of this in vitro study was to evaluate the color stability and degree of conversion (DC) of dual-cure and light-cure cements and flowable composites after thermal aging. MATERIALS AND METHODS: A total of 50 human incisors were prepared and divided into six groups (n = 10). Veneers were fabricated using IPS Empress Direct composite resin were bonded with three types of luting agents: Light-cured, conventional dual, and flowable composite according to the manufacturer's instructions. The groups were as follows: Filtek Z350XT Flow/Single Bond 2, RelyX ARC/Single Bond 2, RelyX Veneer/Single Bond 2, Tetric N-Flow/Tetric N-Bond, and Variolink II/Tetric N-Bond. Commission Internationale de l'Éclairage L*, a* and b* color coordinates were measured 24 h after cementation procedure with a color spectrophotometer and reevaluated after 10,000 thermal cycles. To evaluate the DC 50 specimens (n = 10) of each resin material were obtained and Fourier transform infrared spectroscopy was used to evaluate the absorption spectra. Statistical analysis was performed with one-way ANOVA and Tukey's test (α = 0.05). RESULTS: No statistically significant differences in ΔE* occurred after aging. The greatest change in lightness occurred in the Variolink II resin cement. Changes in red-green hue were very small for the same cement and largest in the Tetric N-Flow flowable resin composite, while the greatest change in blue-yellow hue was a yellowing of the RelyX ARC luting cement. RelyX ARC exhibited the highest DC, and there were no statistically significant differences in DC among the other cements. CONCLUSIONS: Resin-based luting agent might affect the final of ceramic veneer restorations. The thermal aging affected the final color of the evaluated materials, and these were regarded as clinically unacceptable (ΔE >3.3).

Comparison of cone beam computed tomography and digital intraoral radiography performance in the detection of artificially induced recurrent caries-like lesions.

OBJECTIVES: The aim of this study was to compare the performance of cone beam computed tomography (CBCT) and digital radiography in the detection of artificial recurrent caries-like lesions under amalgam and composite fillings. STUDY DESIGN: The study included class II cavities in 30 molars that had been filled with amalgam. Fifteen of those molars had the restoration-enamel interface artificially demineralized. Phantoms were prepared, and CBCT images were acquired with 2 units in 3 voxel sizes (K9000, 0.076 mm; i-CAT, 0.2 mm and 0.4 mm). Intraoral radiographs were obtained with 3 systems (Digora, VistaScan, and RVG-6100). Amalgam fillings were then replaced by composite, and new images were obtained. Three examiners assessed all of the images. Sensitivity, specificity, accuracy, and receiver operating characteristic curve were calculated and verified through analysis of variance and the Tukey test. RESULTS: There were no significant differences in sensitivity and specificity when the same restorative material was present or when the restorative materials were compared with the imaging technique as a constant. As for accuracy and receiver operating characteristic curve, there were statistically significant differences when the 2 materials were compared, and there were differences in the amalgam group when the imaging modalities were compared. CONCLUSIONS: CBCT performed similarly to intraoral radiography in detecting demineralization under restorations. However, the voxel size and the type of restorative material influenced its performance.