Clinical performance of preheating thermoviscous composite resin for non-carious cervical lesions restoration: A 24-month randomized clinical trial.

OBJECTIVES: This 24-month, double-blind, split-mouth randomized clinical trial aimed to compare the retention rates of a preheated thermoviscous composite resin (PHT) compared to a non-heated composite resin (NHT) in non-carious cervical lesions (NCCLs). METHODS: A total of 120 restorations were restored on NCCLs using a preheated (VisCalor bulk, Voco GmbH) and a non-heated (Admira Fusion, Voco GmbH) composite resins with 60 restorations per group. A universal adhesive in the selective enamel conditioning was applied. In the PHT group, composite was heated at 68 °C for using a bench heater. In the NHT group, no heating was employed. Both restorative materials were dispensed into caps and inserted into the NCCLs. The restorations were evaluated at baseline, 6, 12, 18, and after 24 months of clinical service using the FDI criteria. Statistical analysis was performed with Kaplan-Meier estimation analysis for retention/fracture rate and Chi-square test for the other FDI parameters (α=0.05). RESULTS: After 24 months 108 restorations were assessed. Seven restorations were lost (two for PHT group and five for NHT group), and the retention rates (95 % confidence interval [CI]) were 96.7 % (81.5-99.9) for PHT group and 90.8 % (81.1-96.0) for NHT group, with no statistical differences between them (p > 0.05). The hazard ratio (95 % CI) was 0.52 (0.27 to 1.01), with no significant difference within groups. In terms of all other FDI parameters that were assessed, all restorations were deemed clinically acceptable. CONCLUSIONS: Both composites showed high rates of retention rates after 24 months. CLINICAL SIGNIFICANCE: The clinical performance of the new preheated thermoviscous was found to be as good as the non-heated composite after 24-month of clinical evaluation in non-carious cervical lesions. REGISTRATION OF CLINICAL TRIALS: RBR-6d6gxxz.

In-office dental bleaching in adolescents using 6% hydrogen peroxide with different application tips: randomized clinical trial.

OBJECTIVE: Despite the availability of in-office bleaching gels with a 6% concentration of hydrogen peroxide (HP), these gels have not been evaluated in younger patients. They are commercially available with a tip, associated or not with a brush, where the tip with a brush spreads the gel over the entire surface to have a smaller thickness (thin layer) since the manufacturers indicate the application of a thin layer of gel. This randomized, split-mouth, double-blind clinical trial evaluated the efficacy of in-office bleaching with 6% HP in adolescents using different application tips, as well tooth sensitivity (TS) and aesthetic self-perception. METHODOLOGY: Sixty participants were randomized for 6% HP self-mixing bleaching gel tip design: without brush and with brush. In-office bleaching was performed in 3 sessions of 50 minutes. Color change was evaluated using a digital spectrophotometer (ΔE ab , ΔE 00 , and ΔWI D ) and color guide (ΔSGU), the absolute risk and intensity of TS with a visual analogue scale and aesthetic self-perception with the oral aesthetic scale (a=0.05). RESULTS: The groups achieved similar bleaching regardless of the application tip (p>0.05). However, only for ΔWI D , a significant mean difference (MD) was observed in the third week (MD 2.3; 95% CI 1.2 to 3.3; p < 0.001) and at one month (MD 1.6; 95% CI 0.6 to 2.6; p < 0.03) favoring the tip without brush. Regarding TS, 45% in the tip-without-brush group and 33% in the tip-with-brush group reported TS (odds ratio 0.61; 95% CI 0.29 to 1.28; p<0.02), with low TS intensity (MD 0.05; 95% CI -0.06 to 0.17; p>0.36). All patients reported improved aesthetic self-perception after bleaching (MD -1.3; 95% -1.8 to -0.9; p<0.001). CONCLUSIONS: Regardless of the tip used bleaching with 6% HP achieved a bleaching efficacy and improved the aesthetic self-perception. However, a lower risk of TS for application using the tip with brush was observed.

Eighteen-month clinical evaluation of a new universal adhesive applied in the "no-waiting" technique: a randomized clinical trial.

OBJECTIVE: The aim of this double-blind, randomized clinical trial was to evaluate the 6- and 18-month clinical performances of a new universal adhesive applied in the "no-waiting" (NW) technique to non-carious cervical lesions (NCCLs) using two evaluation criteria. MATERIALS AND METHODS: One hundred and seventy-six restorations were assigned to four groups according to the adhesive system, adhesive strategy, and application mode: Prime&Bond Active (PB) applied using the etch-and-rinse (ER) and self-etch (SE) strategies with 20 s applications and Clearfil Universal Bond Quick (CQ) applied using the ER and SE strategies with the NW technique. The composite resin restorations were evaluated at baseline and after 6 and 18 months using the World Dental Federation (FDI) and US Public Health Service (USPHS) criteria. The Friedman repeated measures analysis of variance and Wilcoxon test were used for statistical analyses (α = 0.05). RESULTS: No significant differences were observed among any of the groups or criteria after 6 months (p > 0.05). After 18 months, 10 restorations were lost (p > 0.05) (2 with PB-ER [95.5%; 95%CI: 92-100%], 4 with PB-SE [90.9%; 95%CI: 82-98%], 0 with CQ-ER [100%; 95%CI: 92-100%], and 4 with CQ-SE [90.9%; 82-98%]). The restorations performed with the SE strategy showed more marginal discrepancies than those performed with the ER strategy, mainly when the FDI criteria were used (p < 0.05). Those that used the PB-SE showed fewer marginal discrepancies than those that used the CQ-SE (FDI; p < 0.05). A few restorations showed marginal discrepancies after the USPHS analysis (p > 0.05). CONCLUSIONS: The results when using the CQ-SE and -ER strategies with the NW technique were similar to those when using the PB-SE and -ER strategies in standard applications to non-carious cervical lesions after 6 and 18 months of clinical evaluation. CLINICAL RELEVANCE: After 6 and 18 months, the application of Clearfil Universal Bond Quick with the "no-waiting" technique showed similar clinical performance compared to the standard application of Prime & Bond Active applied using the standard application time (20 s). TRIAL REGISTRATION: ClinicalTrials.gov identifier RBR-5f9gps.

In-office dental bleaching in adolescents using 6% hydrogen peroxide with different application tips: randomized clinical trial

Abstract Despite the availability of in-office bleaching gels with a 6% concentration of hydrogen peroxide (HP), these gels have not been evaluated in younger patients. They are commercially available with a tip, associated or not with a brush, where the tip with a brush spreads the gel over the entire surface to have a smaller thickness (thin layer) since the manufacturers indicate the application of a thin layer of gel. Objective This randomized, split-mouth, double-blind clinical trial evaluated the efficacy of in-office bleaching with 6% HP in adolescents using different application tips, as well tooth sensitivity (TS) and aesthetic self-perception. Methodology Sixty participants were randomized for 6% HP self-mixing bleaching gel tip design: without brush and with brush. In-office bleaching was performed in 3 sessions of 50 minutes. Color change was evaluated using a digital spectrophotometer (ΔE ab , ΔE 00 , and ΔWI D ) and color guide (ΔSGU), the absolute risk and intensity of TS with a visual analogue scale and aesthetic self-perception with the oral aesthetic scale (a=0.05). Results The groups achieved similar bleaching regardless of the application tip (p>0.05). However, only for ΔWI D , a significant mean difference (MD) was observed in the third week (MD 2.3; 95% CI 1.2 to 3.3; p < 0.001) and at one month (MD 1.6; 95% CI 0.6 to 2.6; p < 0.03) favoring the tip without brush. Regarding TS, 45% in the tip-without-brush group and 33% in the tip-with-brush group reported TS (odds ratio 0.61; 95% CI 0.29 to 1.28; p<0.02), with low TS intensity (MD 0.05; 95% CI -0.06 to 0.17; p>0.36). All patients reported improved aesthetic self-perception after bleaching (MD -1.3; 95% -1.8 to -0.9; p<0.001). Conclusions Regardless of the tip used bleaching with 6% HP achieved a bleaching efficacy and improved the aesthetic self-perception. However, a lower risk of TS for application using the tip with brush was observed.

Bond strength and internal adaptation of customized glass fiber posts using different bulk-fill flow resins.

Background: This study aimed to evaluate the bond strength and internal adaptation of customized glass fiber posts using Bulk Fill flowable composite resins (BF) and conventional composite resin. Material and Methods: Fifty bovine teeth were randomly divided (n=10) according to the following groups: G1 (control): glass fiber posts were adapted to the root canal and luted with Rely-X ARC cement (3M® ESPE); G2: fiber posts smaller than the root canal diameter were customized using Filtek™ Z350 XT (3M® ESPE) conventional composite resin, and luted similarly to Group 1. G3: posts were customized with Tetric N-Ceram Bulk Fill composite resin (Ivoclar Vivadent AG), G4: posts were customized with Filtek™ Bulk Fill Flow (3M® ESPE), and G5: posts were customized with SureFil SDRTM flow (DENTSPLY), respectively. The specimens were submitted to push-out testing and internal adaptation evaluation using optical microscopy. Push-out (MPa) and internal adaptation (%) data were subjected to ANOVA and Tukey's post-hoc tests (p = 5%). Results: No statistically significant differences were found in both evaluations (p<0.05). Conclusions: Customized glass fiber posts using different bulk fill flowable composites did not affect the post bond-strength and internal adaptation, presenting similar results to customized glass fiber posts using conventional composite or posts with no previous customization. Key words:Dental pulp, composite resins, fiber posts, glass fiber post.

Emergency management of dental avulsion and replantation: knowledge of undergraduate health care students / Manejo emergencial da avulsão dentária e do reimplante: conhecimento dos estudantes degraduação na área de saúde

Dental replantationis a major problem in public health. Its prognosis depends on emergency care, butthere is a lack of knowledge on it. So, this study aims to evaluate the knowledge of undergraduate students of Dentistry, Speech Therapy, Physical Education, Pedagogy,and Technologist in Radiology. One hundred and fifty-onestudents answered tenquestions about emergency replantation care. Then, an educational lecture was performed. The same questions were asked again to the same students to reevaluate their answers. The statisticaltests were employed at a significant level of p<0.05. There wasa significant difference (p<0.05)inthe responsesbefore and after the lecture. The dental students had a higher knowledge ofthe subject (p<0.05). The educational presentation reached its objective, since there was an improvement in the index of all answers of the post-lecture questionnaire, demonstrating thatthe people must be informedand trainedin the emergency management of dental avulsion (AU).

O reimplante dentário é um grande problema de saúde pública. Seu prognóstico depende do atendimento de urgência, mas ainda falta conhecimento.Assim, este estudo tem como objetivo avaliar o conhecimento de graduandos de Odontologia, Fonoaudiologia, Educação Física, Pedagogia e Tecnólogo em Radiologia. Cento e cinquenta e umalunos responderam a 10 perguntas sobre cuidados de reimplante de emergência. Em seguida, foi realizada uma palestra educativa. As mesmas perguntas foram feitas novamente aos mesmos alunos para reavaliar suas respostas. Os testes estatísticos foram empregados em um nível de significância de p <0,05. Houve diferença significativa (p <0,05) nas respostas antes e depois da palestra. Os estudantes de odontologia apresentaram maior conhecimento sobre o assunto (p <0,05). A apresentação educativa atingiu seu objetivo, visto que houve uma melhora no índice de todas as respostas do questionário pós-aula, demonstrando que as pessoas devem ser informadas e treinadas no manejo emergencial da avulsão dentária (AU).

Evaluation of the Bond Strength of Densely Sintered Ceramics Subjected to Extended Firing.

INTRODUCTION: Critical failures in ceramic materials can be caused by the processing mode, which includes all steps taken in the manufacture of a ceramic part, from molding to firing. PURPOSE: To evaluate the effect of extended firing on bond strength in densely sintered ceramics of the zirconium reinforced lithium silicate, lithium disilicate, and feldspathic ceramic. MATERIALS AND METHODS: Three types of ceramics were evaluated: zirconium reinforced lithium silicate, lithium disilicate, feldspathic ceramic. A total of 6 ceramic blocks, two for each material were used in the study. Each block was cut into four square sections. A total of 24 ceramic surfaces were randomly distributed into 6 groups (n = 4 surfaces per group) divided according to the variables: heat treatment: conventional firing or extended firing; test time: immediate (24 hours after cementation) or longevity (after 1000 cycles of thermocycling). The bond strength tests were performed in a semi-universal test machine for microshear bond strength. For data analysis, the Shapiro-Wilk test was performed to evaluate the normality between the groups measured, and regarding homoscedasticity (homogeneity of variances) by the Bartlett test. The comparisons between the groups were made using the nonparametric Kruskal-Wallis test. RESULTS: There was no statistically significant difference of the resistance values in relation to the thermal treatment methods (conventional firing and extended firing) in any ceramic group (p <0.05). Among the times (immediate and long), there was a statistically significant difference (p <0.05), with higher resistance values for immediate time. CONCLUSION: Extended firing did not influence the micro-shear bond strength of zirconium reinforced lithium silicate, lithium disilicate, feldspathic ceramic.

Influence of the geometry of the screwdriver-screw connection on the reverse torque of UCLA screws.

The aim of this study was to evaluate the influence of the geometry of the screwdriver-screw connection on the reverse torque of UCLA screws after repeated cycles of tightening and loosening in an implant-supported prosthesis. Thirty sets of external hex titanium implants, UCLA abutments, and UCLA abutment screws were divided into 3 experimental groups (n = 10). In the square group, the implant and UCLA abutment system were mounted in an upright position using a screw with a square screwdriver-screw connection. In the hexagonal group, the implant and UCLA abutment system were mounted in an upright position using a screw with a hexagonal screwdriver-screw connection. In the hexalobular group, the implant and UCLA abutment system were mounted at 70° using a dynamic UCLA abutment and screw with a hexalobular screwdriver-screw connection. Ten alternating torque-reverse torque cycles were applied to each screw using a screwdriver fixed at the end of a digital torque meter. The screws with a square connection resulted in less loss of reverse torque than the other types. Screws with a hexagonal connection showed a statistically significant loss of torque initially but remained constant for the remaining cycles. For the screws with a hexalobular connection, the loss of torque was greater, and substantial deformation of the plastic in the microstructure was noted. The screwdriver-screw connection geometry had a direct influence on the reverse torque of UCLA screws, and the initial reverse torque of the abutment screws with a square connection was greater than that of the hexagonal and hexalobular designs.

Clinical effects of the exposure to red wine during at-home bleaching.

OBJECTIVES: This clinical trial evaluated the effects of red wine exposure on the effectiveness of at-home bleaching with 10% carbamide peroxide, degree of tooth sensitivity, and levels of periodontal inflammatory markers. METHOD AND MATERIALS: Eighty participants were assigned to two groups, namely, those who drank red wine (experimental group), and those who did not drink red wine (control group). The experimental group participants rinsed their mouths with 25 mL of red wine four times a day during the bleaching period. Shade evaluation was assessed visually by using the Vita Classical and Vita Easyshade techniques. Tooth sensitivity was evaluated by the numeric and visual analog scales, and the salivary and gingival crevicular fluids were collected for assessment of nitric oxide (NO) levels, a marker of inflammation. Differences in color change were analyzed by one-way analysis of variance (ANOVA). The absolute risks of tooth sensitivity were compared by the Fisher exact test. Tooth sensitivity intensity data sets for both the visual analog scale and the numeric rating scale were compared using the Wilcoxon signed rank test (α = .05). Repeated measures and two-way ANOVA followed by the Bonferroni test were used to assess time-course and differences between groups in NO production. RESULTS: The bleaching technique was effective regardless of wine consumption (P > .05). Tooth sensitivity was classified as mild, with no differences between groups (P > .05). Red wine reduced both the gingival crevicular fluid and salivary levels of NO (P < .05). CONCLUSION: Red wine does not interfere with the effectiveness and sensitivity of at-home teeth bleaching with 10% carbamide peroxide and protects against bleaching-induced inflammation.

Assessment of the aesthetic impact and quality of life of home dental bleaching in adult patients.

BACKGROUND: This study aimed to evaluate the impact of home bleaching with 10% carbamide peroxide on the quality of life and aesthetic perception of patients. MATERIAL AND METHODS: A total of 107 patients between 18 and 38 years of age with good oral and general health and at least one anterior tooth in color A2 or darker were selected. Patients who previously underwent any type of bleaching procedures were excluded. All patients received a home bleaching treatment with 10% carbamide peroxide. Before beginning the bleaching treatment, the selected patients responded a form with the Oral Health Impact Profile short form (OHIP-14) and Oral Aesthetic Subjective Impact Scale (OASIS) questionnaire. One month after the bleaching treatment, the patients answered the same questionnaires again. The mean ΔE after bleaching was obtained for the canines and lateral and central incisors. The OHIP-14 and OASIS data were measured for the total sample before and after bleaching using the Wilcoxon signed-rank test with a 5% significance level. RESULTS: The effectiveness of whitening by significant color variation was observed in all groups of teeth with less variation in ΔE for central incisors. Comparing before and after bleaching, there was no significant difference in impact for any of the seven domains and total OHIP-14 scores, although a decrease was observed in the discomfort and psychological disability domains. As for the self-perception of dental aesthetics, measured by the OASIS, there was also no significant difference for all the items evaluated; however, it was possible to observe an increase in "concern with dental appearance" after bleaching. CONCLUSIONS: Home bleaching with 10% carbamide peroxide did not have a significant impact on patients' quality of life and aesthetic perception, although there was a decrease in the domain of psychological discomfort and an increase in concerns about dental appearance. Key words:Tooth Bleaching, quality of life, self-perception, dental aesthetics.

Effect of Addition of Dimethyl Sulfoxide to Simplified Adhesives on Dentin Bond Durability after Three Years of Water Storage.

PURPOSE: To evaluate the effect of inclusion of two dimethyl sulfoxide (DMSO) concentrations in simplified etch-and-rinse adhesives on dentin bonding durability after three years of water storage. MATERIALS AND METHODS: Forty-two caries-free third molars were divided into six experimental groups (n = 7) according to the following factors: 1) adhesive (Adper Single Bond 2 [SB], 3M Oral Care; Prime&Bond 2.1 [PB], Dentsply Sirona); 2) concentration of DMSO (control group: 0.0% DMSO; addition of 0.2% DMSO [0.2] and 2% DMSO [2.0]). After completing restoration, specimens were stored in water (37°C) for 24 h, sectioned into adhesive-dentin sticks (0.8 mm2), tested for microtensile bond strength (µTBS) at 0.5 mm/min, and examined for nanoleakage (NL) using SEM immediately thereafter or after three years of water storage. Data were subjected to a three-way repeated-measures ANOVA and Tukey's test (α = 0.05) for each property evaluated. RESULTS: After three years of water storage, for both adhesives, the incorporation of 2% DMSO maintained the µTBS when compared to immediate µTBS (p > 0.05). In general, SB resulted in a statistically significantly higher mean of µTBS compared to PB, independent of the DMSO concentration after water storage (p < 0.05). Furthermore, the amount of NL was lower and practically limited to the hybrid layer given the concentrations of 0.2% and 2% DMSO for both tested adhesives after three years. CONCLUSION: The incorporation of DMSO in simplified etch-and-rinse adhesives maintains the long-term stability of the dentin bond.

Personality traits, psychosocial effects and quality of life of patients submitted to dental bleaching.

BACKGROUND: Perception is defined as the ability to distinguish through the senses. All perception is dependent on factors such as personality, previously lived experiences and cultural elements. When planning an aesthetic treatment, consider the way the patients perceive the changes and outcomes is essential for reaching their expectations. The objective of this study was to assess if there was predominance of a personality trait of patient undergoing dental bleaching and if this treatment could promote changes in this traits, in the psychosocial impact and quality of life of these individuals. METHODS: The assessment of personality characteristics, quality of life, psychosocial and self-perception was a cross-sectional observational study and it was carried out by applying questionnaires to 55 patients that were submitted to a clinical phase. The psychometric instruments used were NEO FFI-R (personality), PIDAQ (psychosocial effect) and WHOQOL-BREF (quality of life). Each test domain was prior and after bleaching by Wilcoxon Signed Rank test (α = 0.05). The internal consistencies of each scale were evaluated by Cronbach's alpha. RESULTS: No statistical significant differences among personality traits means were observed among participants but there was predominance of two predominant personality traits in this study: conscientiousness (45.5%) and extraversion (34.5%). In four test domains of the PIDAQ, significant differences were observed before and after dental bleaching. The overall perception of the PIDAQ was also statistically significant demonstrating an improvement. There were no differences on overall or specific domains scores of the WHOQOL before and after treatment. CONCLUSIONS: Subjects who underwent dental treatment improved their self-confidence and reduced concerns about dental aesthetics, social and personality impact of dental alterations. TRIAL REGISTRATION: This study was conducted in parallel to a clinical investigation that aimed to evaluate tooth sensitivity related to dental bleaching technique and registered in REBEC clinical registry under protocol RBR-6pt2n3 in 13 November 2013.

Effect of surface treatments on the adhesive properties of metallic brackets on fluorotic enamel.

OBJECTIVE: To compare the effectiveness of the pretreatment with sandblasting and deproteinization with NaOCl on bond strength (SBS), in situ conversion degree (CD) of brackets in fluorotic enamel, and enamel etching pattern. METHODS: A total of 90 non-carious maxillary premolars were used. The teeth were then assigned to six experimental groups according to: enamel surface (sound and fluorotic enamel); surface treatment (Regular etch with 37% phosphoric acid [RE]; 5.2% sodium hypochlorite + phosphoric acid [NaOCl + RE]; sandblasting + phosphoric acid [sandblasting + RE]). After storage in distilled water (37°C/24h), the specimens were tested at 1 mm/min until failure (SBS). Enamel-resin cement interfaces were evaluated for CD using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a scanning electron microscope. Data from SBS and in situ CD values were analyzed using ANOVA two-away and Tukey test (α=0.05). The enamel etching pattern was evaluated only qualitatively. RESULTS: For sound enamel, RE showed the highest SBS values, when compared to NaOCl + RE and Sandblasting + RE groups (p< 0.01). Regarding CD, only NaOCl + RE significantly compromised the mean DC, in comparison with other groups (p= 0.002). For fluorotic enamel, the Sandblasting + RE group significantly increased the mean SBS values, in comparison with RE group (p= 0.01) and no significant change was observed for CD (p> 0.52). CONCLUSIONS: The application of NaOCl or sandblasting associated to phosphoric acid improved the SBS of the brackets in fluorotic enamel without compromising the CD of the resin cement, with improving of enamel interprismatic conditioning.

Effect of surface treatments on the adhesive properties of metallic brackets on fluorotic enamel

ABSTRACT Objective: To compare the effectiveness of the pretreatment with sandblasting and deproteinization with NaOCl on bond strength (SBS), in situ conversion degree (CD) of brackets in fluorotic enamel, and enamel etching pattern. Methods: A total of 90 non-carious maxillary premolars were used. The teeth were then assigned to six experimental groups according to: enamel surface (sound and fluorotic enamel); surface treatment (Regular etch with 37% phosphoric acid [RE]; 5.2% sodium hypochlorite + phosphoric acid [NaOCl + RE]; sandblasting + phosphoric acid [sandblasting + RE]). After storage in distilled water (37°C/24h), the specimens were tested at 1 mm/min until failure (SBS). Enamel-resin cement interfaces were evaluated for CD using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a scanning electron microscope. Data from SBS and in situ CD values were analyzed using ANOVA two-away and Tukey test (α=0.05). The enamel etching pattern was evaluated only qualitatively. Results: For sound enamel, RE showed the highest SBS values, when compared to NaOCl + RE and Sandblasting + RE groups (p< 0.01). Regarding CD, only NaOCl + RE significantly compromised the mean DC, in comparison with other groups (p= 0.002). For fluorotic enamel, the Sandblasting + RE group significantly increased the mean SBS values, in comparison with RE group (p= 0.01) and no significant change was observed for CD (p> 0.52). Conclusions: The application of NaOCl or sandblasting associated to phosphoric acid improved the SBS of the brackets in fluorotic enamel without compromising the CD of the resin cement, with improving of enamel interprismatic conditioning.

RESUMO Objetivo: Comparar a efetividade do pré-tratamento com jateamento e desproteinização com NaOCl na resistência de união (SBS), grau de conversão in situ (GC) dos braquetes metálicos ao esmalte fluorótico e o padrão de condicionamento do esmalte. Métodos: Foi utilizado um total de 90 pré-molares superiores livres de cárie. Os dentes foram divididos em seis grupos experimentais, de acordo com: superfície do esmalte (Esmalte Sadio e Fluorótico); tratamento de superfície (Condicionamento com ácido fosfórico a 37% [ER]; Hipoclorito de sódio a 5,2% + ácido fosfórico [NaOCl + ER]; e jateamento + ácido fosfórico [Jateamento + ER]). Após armazenamento em água destilada (37oC/24 h), os espécimes foram testados a 1 mm/min até a falha (SBS). As interfaces esmalte-cimento foram avaliadas para GC usando espectroscopia micro-Raman. O padrão do condicionamento do esmalte foi avaliado sob microscopia eletrônica de varredura. Os dados da SBS e GC foram analisados utilizando ANOVA dois fatores e teste de Tukey (α= 0,05). O padrão de condicionamento do esmalte foi avaliado apenas qualitativamente. Resultados: Para o esmalte sadio, o ER apresentou os maiores valores de SBS, quando comparado aos grupos NaOCl + ER e Jateamento + ER (p< 0,01). Em relação ao GC, apenas a média do grupo NaOCl + ER foi comprometida significativamente em comparação aos outros grupos (p= 0,002). Para o esmalte fluorótico, Jateamento + ER aumentou significativamente a média dos valores de SBS, em comparação com o grupo ER (p= 0,01) e nenhuma mudança significativa foi observada no GC (p> 0,52). Conclusões: A aplicação de NaOCl ou jateamento associado ao ácido fosfórico melhorou a SBS dos braquetes no esmalte fluorótico sem comprometer o GC do cimento resinoso, com a melhoria do condicionamento interprismático do esmalte.

Co-Loaded Curcumin and Methotrexate Nanocapsules Enhance Cytotoxicity against Non-Small-Cell Lung Cancer Cells.

Background: As part of the efforts to find natural alternatives for cancer treatment and to overcome the barriers of cellular resistance to chemotherapeutic agents, polymeric nanocapsules containing curcumin and/or methotrexate were prepared by an interfacial deposition of preformed polymer method. Methods: Physicochemical properties, drug release experiments and in vitro cytotoxicity of these nanocapsules were performed against the Calu-3 lung cancer cell line. Results: The colloidal suspensions of nanocapsules showed suitable size (287 to 325 nm), negative charge (-33 to -41 mV) and high encapsulation efficiency (82.4 to 99.4%). Spherical particles at nanoscale dimensions were observed by scanning electron microscopy. X-ray diffraction analysis indicated that nanocapsules exhibited a non-crystalline pattern with a remarkable decrease of crystalline peaks of the raw materials. Fourier-transform infrared spectra demonstrated no chemical bond between the drug(s) and polymers. Drug release experiments evidenced a controlled release pattern with no burst effect for nanocapsules containing curcumin and/or methotrexate. The nanoformulation containing curcumin and methotrexate (NCUR/MTX-2) statistically decreased the cell viability of Calu-3. The fluorescence and morphological analyses presented a predominance of early apoptosis and late apoptosis as the main death mechanisms for Calu-3. Conclusions: Curcumin and methotrexate co-loaded nanocapsules can be further used as a novel therapeutic strategy for treating non-small-cell lung cancer.

The Effect of Viscosity and Application Mode of Phosphoric Acid on Bond Strength of GlassFiber Post.

BACKGROUND: When a phosphoric acid is used, before applying an adhesive system, it is known that obtaining an effective adhesion to the root canal walls is a challenge. The aim of the present study was to evaluate the influence of phosphoric acid viscosity and application mode on the push-out bond strength (BS) values of fiberglass post to root dentin. The conditioning pattern on the root dentin was also evaluated. MATERIALS AND METHODS: The roots of 44 endodontically treated premolars were divided into 4 groups, of eleven teeth each, according to the combination of the main factors: phosphoric acid viscosity (liquid or gel) and application mode (passive or sonic). After application of the two-step etch-and-rinse adhesive system, the fiberglass posts were cemented with a dual-cure resin-cement. Roots were sectioned transversely into six 1-mm slices for push-out BS test at 0.5 mm/min. Some roots of each group were selected for evaluation of the conditioning pattern by scanning electron microscopy. BS results (three-way ANOVA and Tukey's test) and the conditioning pattern (Kruskal-Wallis test and Mann-Whitney test) were statistically evaluated (α= 0.05). RESULTS: The highest BS value was observed with a liquid phosphoric acid under sonic application mode (p < 0.05), being all other groups similar to one another (p < 0.05). Also, the highest BS value was observed in the cervical third, followed by the medium and the apical thirds (p < 0.05). The sonic application produced better smear layer removal and opening of dentinal tubules for both viscosities (p = 0.015). CONCLUSION: A better bonding of fiberglass posts to root canals can be achieved when the post spaces are conditioned with a liquid phosphoric acid under sonic application.

Improving bonding to eroded dentin by using collagen cross-linking agents: 2 years of water storage.

OBJECTIVES: The aim of this study was to investigate the effects of collagen cross-linking agents on nanomechanical and bonding properties of eroded dentin (ED), 24 h and 2 years after water storage. MATERIALS AND METHODS: Human molar dentin surfaces, eroded by soft drinks or citric acid, were acid-etched and treated with primers containing proanthocyanidin (PA) and riboflavin (RI) or were untreated (control) and tested after 24 h and 2 years. After acid etching and adhesive application (Prime&Bond Elect (PBE); Scotchbond Universal (SBU); Tetric n-bond Universal (TEU)), specimens were sectioned into beams and tested for microtensile bond strength (µTBS) and silver nitrate deposition (NL) after 24 h and 2 years. The beams were used to evaluate the 24-h in situ conversion of degree (DC). Nanohardness (NH) and Young's modulus (YM) were evaluated via resin-bonded dentin slices after 24 h and 2 years. A three-way ANOVA and Tukey's test were used for statistical analysis (5%). RESULTS: For both storage times, ED with citric acid resulted in lower µTBS, NH, and YM and higher NL for each adhesive system than soft drink ED (p < 0.05). After 2 years of water storage, cross-linking primers maintained the µTBS, NH, and YM (p < 0.05) when compared with the control group. Althougth, the NL values decreased for all groups after 2 years of water storage, PA and RI treatments showed NI values lower than control group (p < 0.001). No significant differences were observed between PA and RI treatments (p > 0.05). Cross-linking primers maintain or improve DC (p < 0.03). In general, TEU and SBU yielded higher µTBS, DC, NH, and YM and lower NL than PBE. CONCLUSION: Cross-linking agents improved the results and maintained the resin-ED interface bonding and nanomechanical properties, without jeopardizing adhesive polymerization. CLINICAL RELEVANCE: Cross-linking agents are a viable alternative for improving and maintaining resin-ED interface bonding and nanomechanical properties.

Pretratamiento y mejoría de la fuerza de unión de los cementos autoadhesivos de resina a los postes / Pretreatment and improvement of bonding strength of self-adhesive resin cements to posts

ABSTRACT Introduction: Posts and core are frequently used in endodontically treated teeth with excessive loss of coronal tooth structure. Objective: To evaluate the effectiveness of self-adhesive cements under different pre-treatments of dentin in the resistance to extrusion of fiberglass posts. Methods: An experimental in vitro study was conducted. The randomly selected sample was 56 extracted bovine incisors with mature apices and without root curvature. Before the cementing procedure, pretreatment of dentin was performed with 11.5 percent polyacrylic acid, 17 percent EDTA or sodium hypochlorite. The type of failure between the post/cement/dentin was evaluated by stereomicroscope. Two hundred and sixteen bovine dentin discs were used. The disks were approximately 1 mm thick, and were obtained from 72 bovine roots restored with intraradicular retentions. Data were analyzed for better comprehension in an SPSS database for Windows version 15. Results: The highest values were found in groups G3, G4 and G5, and there was no bond strength significant difference in group G2. Conclusions: The pre-treatment had no effect on dentin bond strength, and the self-adhesive cement RelyX U100 appears to be a viable option in the cementation of fiber posts(AU)

RESUMEN Introducción: Los postes y el núcleo se utilizan con frecuencia en los dientes tratados endodónticamente con una pérdida excesiva de la estructura dental coronal. Objetivo: Evaluar la efectividad de los cementos autoadhesivos bajo diferentes pretratamientos de dentina en la resistencia a la extrusión de postes de fibra de vidrio. Métodos: Se realizó una investigación experimental in vitro en 56 dientes de ganado seleccionados al azar con cierre apical maduro y sin curvaturas radiculares. Antes del procedimiento de cementación, se llevó a cabo el pretratamiento de la dentina con 11,5 por ciento de ácido poliacrílico, 17 por ciento de EDTA o hipoclorito de sodio. El estereomicroscopio evaluó el tipo de falla entre el poste / cemento / dentina. Se usaron 216 discos de dentina bovina. Los discos tenían aproximadamente 1 mm de espesor y se obtuvieron de 72 raíces bovinas restauradas con retenciones intrarradiculares. Los datos se analizaron para una mejor comprensión en una base de datos de SPSS para Windows versión 15. Resultados: Los valores más elevados fueron encontrados en los grupos G3, G4 y G5 y no fue significativa la prueba de resistencia en el grupo G2. Conclusiones: El pretratamiento no tuvo efecto sobre la fuerza de unión dentinaria, y el cemento autoadhesivo RelyX U100 parece ser una opción viable en la cementación postes de fibra(AU)

Effect of Phosphoric Acid Containing MMP-Inactivator on the Properties of Resin Bonding to Eroded Dentin.

PURPOSE: To evaluate the effect of two phosphoric acids containing protease inactivators (chlorhexidine and proanthocyanidin) on the resin/eroded-dentin microtensile bond strength (µTBS), nanoleakage (NL), and in situ degree of conversion (DC) of three universal adhesives applied in the etch-and-rinse mode. MATERIALS AND METHODS: One hundred twenty-six molars were randomly assigned to 18 experimental conditions according to the combination of the independent variables: eroded dentin (soft drink and citric acid), adhesive (Prime&Bond Elect [PBE, Dentsply Sirona], Scotchbond Universal Adhesive [SBU, 3M Oral Care], and Tetric N-Bond Universal [TEU, Ivoclar Vivadent]), and acid pretreatment (conventional phosphoric acid [CP acid]; chlorhexidine acid [CHX acid]; and proanthocyanidin acid [PA acid]). After restorations, specimens were sectioned into resin-dentin sticks (ca 0.8 mm2) that were then tested under tension (crosshead speed: 0.5 mm/min). Selected sticks from each tooth were used to evaluate NL and DC. Data from all tests were subjected to three-way ANOVA and Tukey's test (α=0.05). RESULTS: Dentin eroded with citric acid showed a significant reduction in µTBS for each adhesive in comparison to dentin eroded with the soft drink (p < 0.001). For dentin eroded with CHX acid and PA acid, the µTBS (p > 0.03) significantly improved and NL decreased for all adhesives (p < 0.004); in addition, the DC improved for two of the three adhesives tested (SBU and TEU) (p < 0.03) when CHX acid and PA acid were compared to CP acid. CONCLUSION: The addition of chlorhexidine and proanthocyanidin to phosphoric acid improved the adhesive performance when compared with conventional phosphoric acid, without jeopardizing adhesive polymerization at the resin/eroded-dentin interface.

Hydrogen peroxide-based products alter inflammatory and tissue damage-related proteins in the gingival crevicular fluid of healthy volunteers: a randomized trial.

Hydrogen peroxide (H2O2)-based products are effective in tooth whitening; however, their safety is controversial as they may harm patient tissues/cells. These effects are suggested to be concentration-dependent; nonetheless, to date, there are no reports on H2O2-mediated oxidative damage in the gingival tissue, and neither whether this can be detected in gingival crevicular fluid (GCF) samples. We hypothesize that H2O2 whitening products may cause collateral oxidative tissue damage following in office application. Therefore, H2O2 and nitric oxide (NO) levels were investigated in GCF samples obtained from patients undergoing dental bleaching with H2O2 at different concentrations, in a randomized, double-blind, split-mouth clinical trial. A proteomic analysis of these samples was also performed. H2O2-based whitening products promoted inflammation which was detected in GCF samples and lasted for longer following 35% H2O2 bleaching. This included time-dependent changes in NO levels and in the abundance of proteins associated with NO synthesis, oxidative stress, neutrophil regulation, nucleic acid damage, cell survival and/or tissue regeneration. Overall, H2O2-based products used in office promote inflammation irrespective of their concentration. As the inflammation caused by 35% H2O2 is longer, patients may benefit better from using lower concentrations of this bleaching product, as they may result in less tissue damage.