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Objectives: This study aimed to investigate the effect of the application method of 2% chlorhexidine (CHX) and its influence on the adhesion of fiberglass posts cemented with a self-adhesive resin cement. Materials and Methods: Sixty human mandibular premolars were endodontically treated and divided into 5 groups (n = 12), according to the canal irrigant and its application method: 2 groups with conventional syringe irrigation (CSI)-2.5% sodium hypochlorite (NaOCl) (control) and 2% CHX- and 3 groups with 2% CHX irrigation/activation-by passive ultrasonic irrigation (PUI), Easy Clean file, and XP-Endo Finisher file. Two roots per group were evaluated for smear layer (SL) removal by scanning electron microscopy. For other roots, fiber posts were luted using a self-adhesive resin cement. The roots were sectioned into 6 slices for push-out bond strength (BS) (7/group) and nanoleakage (NL) (3/group). Data from SL removal were submitted to Kruskal-Wallis and Student-Newman-Keuls tests (α = 0.05). Data from BS and NL were evaluated by 2-way analysis of variance and Tukey's test (α = 0.05). Results: For SL removal and BS, the CHX irrigation/activation promoted better values than CSI with CHX (p < 0.05), but it was not significantly different from CSI with NaOCl (p > 0.05). For NL, the lowest values were obtained by the chlorhexidine irrigation/activation groups (p < 0.05). Conclusions: Active 2% CHX irrigation can be used to improve the post space cleaning and adhesion before fiber post cementation with self-adhesive resin cements.

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Aim: The roughness and micromorphology of various surface treatments in aged metal-free crowns and the bond strength of these crowns repaired with composite resin (CR) was evaluated in vitro. Methods: A CR core build-up was confectioned in 60 premolars and prepared for metal-free crowns. Prepared teeth were molded with the addition of silicone, and the laboratory ceromer/fiber-reinforced crowns (SR Adoro/Fibrex Lab) were fabricated. Subsequently, the crowns were cemented and artificially aged in a mechanical fatigue device (1.2 X 106 cycles), then divided into 4 groups (n = 15) according to the surface treatment: 1) phosphoric acid etching (PA); 2) PA + silane application; 3) roughening with a diamond bur + PA; and 4) sandblasting with Al2O3 + PA. After the treatments, the crowns (n = 2) were qualitatively analyzed by scanning electron microscope (SEM) and surface roughness (n = 5) was analyzed before and after the surface treatment (Ra parameter). The remaining crowns (n = 8) received standard repair with an adhesive system (Tetric N-Bond) and a nanohybrid CR (Tetric N-Ceram), and the microshear bond strength (SBS) test was performed (0.5 mm/min). Roughness and SBS data were analyzed by one- and two-way ANOVA, respectively, as well as Tukey's post-test (α = 0.05). Results: Sandblasting with Al2O3 + PA resulted in the highest final roughness and SBS values. The lowest results were observed in the PA group, whereas the silane and diamond bur groups showed intermediate values. Conclusion: It may be concluded that indirect ceromer crowns sandblasted with aluminum oxide prior to PA etching promote increased roughness surface and bond strength values

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The aim of this study was to evaluate different conditioning protocols and sonic/ultrasonic application of an infiltrant resin (IR) in artificial white spot lesions (AWSL). the V/L surfaces of 48 molars were induced to an AWSL and divided in 6 groups, according to the conditioning protocols and application technique: 15% hydrochloric acid (HA) + manual application of the IR; HA + 37% phosphoric acid (PA) + manual application of the IR; HA + ultrasonic application (U) of the IR; HA + sonic application (S) of the IR; PA+HA+S; and PA+HA+U. For the Penetration Depth (PD), the crowns were etched with HA for 120s. The IR Icon® (DMG) was applied according to the manufacturer`s instructions. The crowns were dye penetrated (0.1% red fluorophore rhodamine B isothiocyanate for 12h) and bleached with 30% hydrogen peroxide for 12 h. The discs were immersed in a 50% ethanol solution, containing 100 µM of sodium fluorescein. The PD (in µm) was measured using confocal laser scanning microscopy (20x). The bond strength (BS) was performed by michoshear test (0.5 mm/min). Data were submitted to 2-way ANOVA and Tukey (α=0.05). For BS, the interaction was not significant (p>0.05). For PD, the main factors were significant (application - p<0.001; conditioning technique - p=0.003). The ultrasonic application showed the highest PD values. PA+HA presented higher results than HA. The sonic/ultrasonic applications and the use of phosphoric acid prior to hydrochloric acid improved PD of the infiltrant resin. Conditioning protocols or application techniques did not influence BS values.

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Abstract The aim of this study was to evaluate different conditioning protocols and sonic/ultrasonic application of an infiltrant resin (IR) in artificial white spot lesions (AWSL). the V/L surfaces of 48 molars were induced to an AWSL and divided in 6 groups, according to the conditioning protocols and application technique: 15% hydrochloric acid (HA) + manual application of the IR; HA + 37% phosphoric acid (PA) + manual application of the IR; HA + ultrasonic application (U) of the IR; HA + sonic application (S) of the IR; PA+HA+S; and PA+HA+U. For the Penetration Depth (PD), the crowns were etched with HA for 120s. The IR Icon® (DMG) was applied according to the manufacturer`s instructions. The crowns were dye penetrated (0.1% red fluorophore rhodamine B isothiocyanate for 12h) and bleached with 30% hydrogen peroxide for 12 h. The discs were immersed in a 50% ethanol solution, containing 100 µM of sodium fluorescein. The PD (in µm) was measured using confocal laser scanning microscopy (20x). The bond strength (BS) was performed by michoshear test (0.5 mm/min). Data were submitted to 2-way ANOVA and Tukey (α=0.05). For BS, the interaction was not significant (p>0.05). For PD, the main factors were significant (application - p<0.001; conditioning technique - p=0.003). The ultrasonic application showed the highest PD values. PA+HA presented higher results than HA. The sonic/ultrasonic applications and the use of phosphoric acid prior to hydrochloric acid improved PD of the infiltrant resin. Conditioning protocols or application techniques did not influence BS values.

Resumo: O objetivo deste estudo foi avaliar diferentes protocolos de condicionamento e a aplicação sônica/ultrassônica de uma resina infiltrante (RI) em lesões de mancha branca produzidas artificialmente (LMBA). As superfícies vestibulares/linguais de 48 molares foram induzidas à formação de LMBA e divididas em 6 grupos, de acordo com os protocolos de condicionamento e técnica de aplicação da resina infiltrante: ácido hidroclorídrico 15% (AH) + aplicação manual da RI; AH + ácido fosfórico 37% (AF) + aplicação manual da RI; AH + aplicação ultrassônica da RI (U); AH + aplicação sônica da RI (S); AF + AH + S; e AF + AH + U. para o grau de penetração (GP), condicionou-se as coroas com AH por 120 s. A RI Icon® (DMG) foi aplicada de acordo com as instruções do fabricante. As coroas foram coradas (rodamina B 0,1% por 12 h) e clareadas com peróxido de hidrogênio 30% por 12 h. os discos foram imersos em solução de etanol 50%, contendo 100 µM de fluoresceína sódica. O GP (em µm) foi mensurado por meio de microscopia confocal a laser (20´). A resistência de união (RU) foi calculada pelo teste de microcisalhamento (0,5 mm/min). Os dados foram submetidos ao teste ANOVA 2 fatores e Tukey (α=0,05). Para RU, a interação não foi significante (p>0,05). Para GP, os fatores principais foram significantes (técnica de aplicação - p<0,001; protocolos de condicionamento - p=0,003). A aplicação U mostrou os maiores valores de GP. AF+AH demonstrou resultados superiores ao grupo AH. As aplicações sônica/ultrassônica e o uso do ácido fosfórico antes do ácido hidroclorídrico aumentaram o GP da resina infiltrante. Os protocolos de condicionamento ou as técnicas de aplicação não influenciaram os valores de RU.

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BACKGROUND: Bleaching procedures performed before restorative procedures, due to the oxygen released, affects the quality of bonding restorations. The application of an lower-concentrated antioxidant for one-hour or more can reversal the compromised bonding to bleached enamel, but it was not effective according to the bleaching concentrations applied. The aim of the present study was to evaluate simplified protocol of higher-concentrated sodium ascorbate (35%SA) in bond strength values of enamel bleached with 10%, 16%, 22% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). MATERIAL AND METHODS: Three hundred and forty enamel surfaces of 85 human third molars were used, divided into 17 groups (n=20), according to the following groups: control = no bleaching and no ascorbic acid application; bleaching (CP10%, CP16%, CP22% at-home and HP 35% in-office) and 35%SA application (no application; 35%SA applied twice for 1-min each [SA2×1], twice for 5-min each [SA2×5] and; twice for 10-min each [SA2×10]). After that, adhesive was applied and composite cylinders were made with Filtek Z350 composite. Microshear test was performed in a universal testing machine. BS values were statistically evaluated using ANOVA and Tukey's and Dunnet's (against control) tests, with 5% level of significance. RESULTS: All bleaching concentrations significantly decrease the enamel bond strength results when compared to control group (p<0.05). More concentrated PC (PC22% and PH35%) showed lower enamel bond strength results when compared to lower concentrated PC (PC10% and PC16%; p<0.05). A significant increase of the enamel bond strength results were only observed when SA2×5 and SA2×10 were applied (p<0.05). CONCLUSIONS: The application of 35% sodium ascorbate for twice 5- and 10-min each was an efficient protocol to reverse the bond strength in bleached enamel at the same level as the no bleaching enamel, independently of the bleaching concentration used. Key words:Tooth bleaching, hydrogen peroxide, sodium ascorbate, bond strength.

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Introduction: The purpose of this in vitro study was to assess the effects of anatomic root levels, different adhesive strategies and cementation system on bond strength (BS), nano leakage (NL) and degree of conversion (DC) after fiber posts cementation. Methods and Materials: Sixty-six roots of human premolars were endodontically prepared and divided according to the combination of adhesive application technique (manual passive, manual active and active vibratory) and the cementation system (Adper Single Bond 2/RelyX ARC [SBAR] and Single Bond Universal/RelyX Ultimate [SBUL]). Specimens were transversally sectioned into six 1-mm-thick serial slices, which were subjected to BS testing (n=7), to NL analysis using scanning electron microscopy (SEM) after slice immersion in silver nitrate (n=2), and micro-Raman spectroscopy for DC (n=2). Data were analyzed using two-way ANOVA and Bonferroni post-hoc test (α=5%). Results: Bond strength values significantly increased with active vibratory application technique (P<0.001), no significant difference was noted between adhesive systems. The cementation system Single Bond Universal/RelyX Ultimate demonstrated the lowest nano leakage values (P<0.05). The manual active and vibratory application techniques showed statistically higher degree of conversion values than the manual passive technique at the coronal and medium thirds (P<0.05); and the lowest results were observed with manual passive application to Single Bond Universal/RelyX Ultimate (P=0.016). Conclusion: The study concluded that techniques with active application (vibratory and manual) resulted in higher bond strength values. The mode of adhesive application influence the results.

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Eugenol-based root canal sealers (RCS) have been widely used by clinicians; however, their effect on resinous materials is still questionable. The objective of this study was to evaluate the influence of RCS at 1 week and 6 months' post obturation on the bond strength (BS) of glass fiber posts (GFP) to root dentin, using conventional and self-adhesive cementation systems (CS). The roots of 56 extracted human canines, were divided in eight groups (n=7) according to the combination of the following factors: RCS (with or without eugenol-Endofill and Sealer 26, respectively), storage period post obturation and prior GFP cementation (1 week and 6 months) and cementation systems (Variolink II - conventional resin cement or RelyX U200-self-adhesive resin cement). After one week, the specimens were transversely sectioned into six 1-mm-thick disks and were subjected to the push out BS test. The data were subjected to 3-way ANOVA and Tukey's tests (α=0.05). The BS were not affected by the RCS, neither the CS (P>0.05). Just the period post obturation showed statistically significant differences (P 0.05), where the GFP cemented 6 months after the endodontic treatment showed higher values than those cemented 1 week after it.

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Aim: The objective is to evaluate the influence of different burs used to prepare the root canal space and acid ultrasonic agitation on bond strength (BS) between glass fiber posts (GFP) and root dentin. Methods: After endodontic treatment, the root canal spaces of 36 extracted human canines were prepared, according to the rotary instrument used (n=18): carbide bur (CB), provided by the post manufacturer and a diamond bur (DB). In both groups, the fiber posts were cemented with the adhesive system Ambar and resin cement Allcem, following the manufacturer`s instructions. Previously to the cementation procedures, the groups were subdivided into 2 groups (n=9), according to the phosphoric acid application mode: conventional etching (CE) and active etching (AE), performed by ultrasonic tip, both for 15s. Before the cementation procedures and after the acid application, 1 root of each group was randomly selected for ultrastructural morphological evaluation by SEM. After 1 week of the cementation, 8 specimens per group were transversely sectioned into six 1-mm thick slices, the root canal regions (cervical, medium and apical) were identified and the push-out test was performed to evaluate BS. Data were analyzed by 3-way ANOVA and Tukey test (α=0.05). Results: The results showed that the cross-product interaction of all factors was significant (P=0.035). Higher bond strength values were obtained when a DB with conventional etching, instead of CB, was used to prepare the root post space. Conclusion: It may be concluded that the use of diamond burs with conventional etching yields high BS values in all root canal thirds

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To examine the effect of the alternative coinitiator 4,4'bis dimethylamino benzydrol (BZN) in degree of conversion (DC), mechanical and biological properties of experimental composites. The coinitiator BZN was used in three concentrations (0.2, 0.5 and 1.2%), and the coinitiator DMAEMA was used as control at the same concentrations as above. The molar concentration of camphorquinone (CQ) and coinitiators was kept constant (1:1). The composites were manipulated and submitted to microhardness test (VHN), flexural and compressive strength (in MPa), elastic modulus (GPa), DC (FT-IR) and in vitro cytotoxicity (against 3T3 fibroblastic cells) of the experimental resins. Data were subjected to two-way ANOVA and Tukey post-test (α=0.05). The experimental composite resin with BZN showed higher DC values compared to control DMAEMA groups. For the mechanical properties, microhardness values were higher in BZN groups; flexural strength and elastic modulus were similar between all the groups. Compressive strength for groups BZN0.5 and DMAEMA0.5 were not statistically different, being the lowest values attributed to group BZN0.2. The experimental resins with BZN and DMAEMA were considered nontoxic against 3T3 fibroblasts. The inclusion of the coinitiator BZN in experimental composites was considered nontoxic against 3T3 fibroblast cells, without compromising DC and mechanical properties.

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Abstract To examine the effect of the alternative coinitiator 4,4'bis dimethylamino benzydrol (BZN) in degree of conversion (DC), mechanical and biological properties of experimental composites. The coinitiator BZN was used in three concentrations (0.2, 0.5 and 1.2%), and the coinitiator DMAEMA was used as control at the same concentrations as above. The molar concentration of camphorquinone (CQ) and coinitiators was kept constant (1:1). The composites were manipulated and submitted to microhardness test (VHN), flexural and compressive strength (in MPa), elastic modulus (GPa), DC (FT-IR) and in vitro cytotoxicity (against 3T3 fibroblastic cells) of the experimental resins. Data were subjected to two-way ANOVA and Tukey post-test (α=0.05). The experimental composite resin with BZN showed higher DC values compared to control DMAEMA groups. For the mechanical properties, microhardness values were higher in BZN groups; flexural strength and elastic modulus were similar between all the groups. Compressive strength for groups BZN0.5 and DMAEMA0.5 were not statistically different, being the lowest values attributed to group BZN0.2. The experimental resins with BZN and DMAEMA were considered nontoxic against 3T3 fibroblasts. The inclusion of the coinitiator BZN in experimental composites was considered nontoxic against 3T3 fibroblast cells, without compromising DC and mechanical properties.

Resumo Analisar o efeito do co-iniciador alternativo 4,4'bisdimetilaminobenzidrol (BZN) no grau de conversão (GC) e nas propriedades mecânicas e biológicas de resinas compostas experimentais. O co-iniciador BZN foi utilizado em três concentrações (0,2, 0,5 e 1,2), e o co-iniciador DMAEMA como controle, nas mesmas concentrações acima. A concentração molar entre canforoquinona (CQ) e os co-iniciadores foi mantida constante (1:1). As resinas compostas foram manipuladas e submetidas aos testes de microdureza (VHN), resistência à compressão e flexural (em MPa), módulo de elasticidade (em GPa), GC (em %, por meio de espectroscopia micro-Raman e FTIR com KBr), citotoxicidade in vitro (frente às células fibroblásticas 3T3) das resinas experimentais. Os resultados foram submetidos ao teste ANOVA 1 fator e pós-teste de Tukey (α=0,05). As resinas compostas experimentais com o BZN apresentaram GC e propriedades mecânicas satisfatórias, além de serem consideradas atóxicas a fibroblastos 3T3. A inclusão do co-iniciador BZN à resina composta foi considerada não tóxica frente a células fibroblásticas 3T3 e sem comprometer o grau de conversão e as propriedades mecânicas da mesma.

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The objective of this study was to evaluate the effect of passive or active phosphoric acid (PA) application after hydrofluoric acid (HA) treatment on the microshear bond strength of lithium disilicate. Thirty ceramic discs were made with IPS Emax 2 (10 mm thick and 10 mm diameter). The specimens were divided into 3 groups, A: 9.6% HA application; AF: 9.6% HA application + cleaning with 37% PA in passive mode and AFF: 9.6% HA application + cleaning with 37% PA in active mode. For the microshear test, four tygons (0.9 mm diameter and 0.2 mm high) were filled with resin cement (RelyX Ultimate) and placed on the ceramic disks. After testing, the fracture modes were examined under scanning electron microscopy. Data were analyzed by one-way ANOVA and Tukey's post test (α=0.05). The bond strength values were significantly higher in Group AFF (11.0±2.5 MPa) compared with group A (8.1±2.6 MPa) (p<0.002). AF group was not statistically different (9.4±2.5 MPa) from Group A. It was concluded that the active application of 37% PA after 9.6% HA increases the microshear bond strength values between the resin cement and lithium disilicate ceramic.

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Abstract The objective of this study was to evaluate the effect of passive or active phosphoric acid (PA) application after hydrofluoric acid (HA) treatment on the microshear bond strength of lithium disilicate. Thirty ceramic discs were made with IPS Emax 2 (10 mm thick and 10 mm diameter). The specimens were divided into 3 groups, A: 9.6% HA application; AF: 9.6% HA application + cleaning with 37% PA in passive mode and AFF: 9.6% HA application + cleaning with 37% PA in active mode. For the microshear test, four tygons (0.9 mm diameter and 0.2 mm high) were filled with resin cement (RelyX Ultimate) and placed on the ceramic disks. After testing, the fracture modes were examined under scanning electron microscopy. Data were analyzed by one-way ANOVA and Tukey's post test (α=0.05). The bond strength values were significantly higher in Group AFF (11.0±2.5 MPa) compared with group A (8.1±2.6 MPa) (p<0.002). AF group was not statistically different (9.4±2.5 MPa) from Group A. It was concluded that the active application of 37% PA after 9.6% HA increases the microshear bond strength values between the resin cement and lithium disilicate ceramic.

Resumo O objetivo desse estudo foi avaliar o efeito da aplicação passiva ou ativa do ácido fosfórico após o tratamento com ácido hidrofluorídrico na resistência de união ao microcisalhamento entre cimento resinoso e dissilicato de lítio. Trinta discos foram confeccionados com IPS Emax 2 (10 mm de espessura e 10 mm de diâmetro). Os espécimes foram divididos em três grupos (A: aplicação do ácido hidrofluorídrico 9,6%; AF: aplicação do ácido hidrofluorídrico 9,6% + limpeza com ácido fosfórico 37% em modo passivo; AFF: aplicação do ácido hidrofluorídrico 9,6% + limpeza com ácido fosfórico 37% no modo ativo). Para o teste de microcisalhamento, quatro tygons (0,9 de diâmetro e 0,2 mm de altura) foram preenchidos com cimento resinoso (RelyX Ultimate) e dispostos sobre os discos de cerâmica. Após o teste, os modos de fratura foram examinados por microscopia eletrônica de varredura. Os dados foram analisados estatisticamente por ANOVA e pós-teste de Tukey (α=0,05). Os valores de resistência de união foram significativamente superiores para o grupo AFF (11,0±2,5 MPa), comparado ao grupo A (8,1±2,6 MPa) (p<0,002), mas este não estatisticamente diferente do grupo AF (9,4±2,5 MPa). Concluiu-se que a aplicação ativa do ácido fosfórico 37% após o uso do ácido hidrofluorídrico 9,6% aumenta a resistência de união entre o cimento resinoso e a cerâmica de dissilicato de lítio.

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To evaluate the effect of different in-office bleaching agents on the permeability, roughness and surface microhardness of human enamel. Methods: For evaluation of roughness and microhardness, 40 hemi-faces of 20 premolars were subjected to initial roughness (Ra parameter) and microhardness (VHN) measurements. Thirty-two premolar's crowns were used for permeability test. Then, all specimens were randomly divided into four groups: C - without bleaching (control), HP35 - bleaching with 35% hydrogen peroxide (HP), HPF38 - 38% HP+fluoride, HPC35 - 35% HP+calcium. Final roughness (FR) and microhardness (FM) measurements were evaluated. For permeability, the 32 crowns were immersed in 1% sodium hypochlorite (20 min) and silver nitrate solutions (2 h) and subjected to developing solution under fluorescent light (16 h). Three sections from the crowns were analyzed in light microscope (100x) to evaluate the scores of permeability: Score 0 - no tracer agent penetration; Score 1 - less than half the thickness of enamel penetration; Score 2 - tracer agent reaching half the enamel thickness; Score 3 - entire enamel depth penetration, without reaching dentin and Score 4 - tracer agent reaching dentin. For roughness and microhardness evaluation were used one-way ANOVA and Dunnet post-test for independent samples, and t test for paired samples. For permeability, the data were analyzed by Kruskal Wallis and Dunn tests. Results: A significantly higher permeability and surface roughness were observed in groups HP35, HPF38 and HPC35 compared to the C group, as well as decreased microhardness (p<0.05). Conclusions: All bleaching agents increased permeability and surface roughness, and decreased microhardness of human enamel; thus, the addition of fluoride or calcium was not beneficial...

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This randomized clinical trial evaluated the whitening potential of commercially available toothpastes. Sixty patients were selected and randomly divided into 4 groups (n=15), according to the dentifrice used: GI (control) - Colgate Total 12, GII - Close-up White Now, GIII: Oral-B 3D White, GIV: Colgate Luminous White. Three daily brushings were performed for 2 to 3 min each, during a period of 15 days. Patients had the color of their teeth evaluated before and after the treatment by means of a spectrophotometer (Vita EasyShade - CIE L*a*b*). Data obtained from L values were analyzed by one-way ANOVA and t test. ∆E was also evaluated to calculate color alteration, by NBS criteria. Mean (standard deviation) of initial values were GI: 82.9 (4.9); GII: 83.9 (5.8); GIII: 83.9 (7.2); GIV: 86.4 (3.4) and final values were GI: 84.1 (6.3); GII: 84.6 (6.1); GIII: 84.2 (7.1); GIV: 88.2 (2.8). In conclusion, the dentifrices showed no lightening action on vital teeth, except for Colgate Luminous White; but according to NBS criteria, there was no noticeable visible change to the patients in any group.

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This randomized clinical trial evaluated the whitening potential of commercially available toothpastes. Sixty patients were selected and randomly divided into 4 groups (n=15), according to the dentifrice used: GI (control) - Colgate Total 12, GII - Close-up White Now, GIII: Oral-B 3D White, GIV: Colgate Luminous White. Three daily brushings were performed for 2 to 3 min each, during a period of 15 days. Patients had the color of their teeth evaluated before and after the treatment by means of a spectrophotometer (Vita EasyShade - CIE L*a*b*). Data obtained from L values were analyzed by one-way ANOVA and t test. ∆E was also evaluated to calculate color alteration, by NBS criteria. Mean (standard deviation) of initial values were GI: 82.9 (4.9); GII: 83.9 (5.8); GIII: 83.9 (7.2); GIV: 86.4 (3.4) and final values were GI: 84.1 (6.3); GII: 84.6 (6.1); GIII: 84.2 (7.1); GIV: 88.2 (2.8). In conclusion, the dentifrices showed no lightening action on vital teeth, except for Colgate Luminous White; but according to NBS criteria, there was no noticeable visible change to the patients in any group.

Este estudo clínico randomizado avaliou o potencial clareador de cremes dentais disponíveis no mercado. Materiais e Métodos: Foram selecionados 60 pacientes, os quais foram divididos aleatoriamente em 4 grupos (n=15): GI - controle - Colgate Total 12; GII- Close-up White Now; GIII - Oral-B 3D White; GIV - Colgate Luminous White. Foram realizadas 3 escovações diárias pelo tempo de 2 a 3 minutos, durante um período de 15 dias. Os pacientes tiveram a cor de seus dentes avaliados antes e após o término do tratamento através do espectrofotômetro Vita EasyShade (escala CIE L*a*b*) Os valores de L* foram analisados por ANOVA um fator para amostras independentes e teste t para amostras pareadas. ∆E também foi calculado para verificar alterações de cor, de acordo com os critérios NBS. A média (desvio padrão) dos valores iniciais foi: GI: 82,9(4,9); GII: 83,9(5,8); GIII: 83,9(7,2); GIV: 86,4(3,4); e os valores finais - GI: 84,1(6,3); GII: 84,6(6,1); GIII: 84,2(7,1); GIV: 88,2(2,8), concluindo-se que os dentifrícios analisados neste estudo não apresentaram ação clareadora sobre dentes vitais, com exceção do dentifrício Colgate Luminous White, porém de acordo com os critérios do NBS, não houve alteração visível a olho nu para nenhum dos grupos.

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AIM : To evaluate the influence of finishing and polishing techniques on the surface roughness of two composite resins (CRs) subjected to bleaching procedure. METHODS : Forty-eight CR specimens were divided into six groups (n=8). For G1 to G3, a microhybrid CR (Opallis; FGM) was used, and G4 to G6, received a nanohybrid CR (Brilliant NewLine; Coltène/Whaledent). All specimens were subjected to bleaching procedure with 35% hydrogen peroxide (two 45-min applications, with a 5-day interval). The surface roughness of all specimens was evaluated before and after the bleaching and/or finishing/polishing (Ra parameter) by a roughness meter. After bleaching, the groups were subjected to finishing and polishing procedures: G2 and G5 - felt discs + diamond pastes; and G3 and G6 - silicon rubber tips. The control groups (G1 and G4) had no finishing or polishing treatment after bleaching. Data were analyzed by ANOVA and Tukey's post-test, and t test for paired samples (a=0.05). RESULTS : bleaching treatment increased Ra values for the nanohybrid CR specimens, but both finishing/polishing techniques were able to reduce these values; for the microhybrid specimens, only finishing/polishing with silicon rubber tips decreased the roughness values. CONCLUSIONS : For both microhybrid and nanohybrid CRs, the silicon rubber tips were effective to reduce the surface roughness after bleaching procedure...

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The longevity of resin depends on its binding between the margin of restorations and the polymer, and one factor that influences this aspect is the shrinkage stress. Thus, the working group presents the following systematic review thatverifies the influence of composite resin composition on shrinkage stress. The following electronic databases were searched: MEDLINE (via Ovid and PubMed - 2004 to January 2014), with the keywords: shrinkage stress, degree of conversion, resin composite. For shrinkage stress,, the best results were found when the BISGMA monomer was used and for the inorganic composition, an inverse relationship was observed: the increased inorganic filler content decreases shrinkage stress.

A longevidade de resina depende da sua ligação entre a margem de restaurações e o polímero, e um fator que influencia a este aspecto, é a tensão de contração. Assim, o grupo de trabalho faz a seguinte análise sistemática para verificar a influência da composição das resinas composta na tensão de contração. As seguintes bases de dados eletrônicas foram pesquisadas: MEDLINE (via PubMed e Ovídio - de 2004 a janeiro de 2014), com as palavras-chave: estresse de contração, grau de conversão, resina composta. Para tensão de contração, os melhores resultados foram encontrados quando o monômero BISGMA foi utilizada e para a composição inorgânica, uma relação inversa foi observada: o aumento do teor de carga inorgânica diminui estresse de contração.

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Aim: To evaluate the human enamel permeability after different external bleaching techniques.Methods: The coronal portions of 20 maxillary human incisors were covered with an acidresistant varnish, except the labial surface, to prevent dye penetration of silver nitrate. Thespecimens were divided randomly into four groups (n=5) according to the bleaching treatments:Group 1 (G1) - without bleaching agent (control group), Group 2 (G2) - 35% hydrogen peroxide(HP) – one session of three 10-min applications, Group 3 (G3) - 35% HP – 2 sessions of three10-min applications, and Group 4 (G4) - 6% HP – 14 days (1h/day). G1 was exposed to artificialsaliva only and in the other groups the bleaching agents were applied following the manufacturers’recommendations. After bleaching, teeth were immersed in a 50% silver nitrate solution for 2 hand photodeveloped for 16 h. Then, three longitudinal slices of each tooth were photographedby an optical microscope (100x). The degree of dye penetration was analyzed in the middle thirdof the dental crowns using a 0 to 4 score system (0= no dye penetration, 1= less than half theenamel thickness, 2= half of the enamel thickness, 3= full extent of enamel without reaching thedentin, and 4= tracer agent reaching dentin). The data were analyzed statistically by the Kruskal-Wallis and Dunn tests (α=0.05). Results: The median (1st/3rd interquartiles) ranges were: G1:0(0/0), G2: 2(2/3), G3: 3(3/3) and G4: 3(3/3). G2, G3 and G4 showed significantly higher dyepenetration compared with G1 (p=0.0017). Conclusions: The use of bleaching agents increaseddental enamel permeability, regardless of the bleaching technique.

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A pesar del tan alto éxito clínico de los procedimientos de aclaramiento dental, no todas las dudas sobre su uso han sido explicadas, mucho menos los efectos adversos sobre la resistencia de unión de restauraciones adhesivas en esmalte/dentina, los cuales todavía siguen siendo muy controvertidos. Esta revisión de tema tiene como objetivo analizar conceptos sobre la interacción entre adhesión posaclaramiento y tratamientos para controlar esas interacciones. Con base en la literatura revisada se puede concluir que un tiempo de espera entre aclaramiento y procedimiento restaurativo debe ser por lo menos de 7 días para que todo el oxígeno residual remanente pueda ser liberado de la estructura dental y, en los casos que sea necesario hacer una restauración inmediata al proceso de aclaramiento, el uso de agente antioxidante como ascorbato de sodio 10% en la forma de gel es una alternativa viable para disminuir los efectos del aclaramiento en el procedimiento adhesivo.

Despite the enormous clinical success of dental whitening procedures, not all the questions about their use have been fully explained, especially in relation to the adverse effects on bond strength of adhesive restorations in enamel and dentin, which still remain controversial. This topic review pretends to analyze some of the issues on the interaction between post-whitening adhesion and the treatments to control such interactions. Based on the revised literature, we may conclude that a time delay of at least 7 days between whitening and the restorative procedure is advisable, so that all the remaining residual oxygen can be released from the tooth structure and, where necessary, immediately restore the whitening process, using an antioxidant such as 10% sodium ascorbate (as a gel) is a viable alternative to reduce the effects of whitening on the adhesive process.

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Objetivo: verificar o efeito do clareamento (caseiro e em consultório) na susceptibilidade ao manchamento de uma resina composta e imersão em soluções corantes. Trinta espécimes de resina composta microhíbrida sofreram avaliação de cor inicial (Vita EasyShade) e aleatoriamente divididos em 6 grupos G1: sem clareamento, com imersão em café; G2: sem clareamento, com imersão em vinho; G3: clareado com peróxido de carbamida 10% (PC 10%) e imersão em café; G4: clareado com PC 10% e imersão em vinho; G5: clareado com peróxido de hidrogênio 35% (PH 35%) e imersão café e G6: clareado com PH 35% e imersão em vinho. Em seguida, houve avaliação final de cor. Os resultados foram analisados por ANOVA 2 fatores e Pós-teste de Tukey (α=0,05). Foram avaliados valores de L (luminosidade), sendo as médias (desvio-padrão) dos valores iniciais - G1: 88,22(1,62); G2:86,76(0,86); G3:82,52(2,90); G4:84,72(1,24); G5:85,64(1,92); G6:86,30(1,13), e os valores finais: G1: 78,32(2,24); G2: 76,46(1,61); G3: 74,60(0,92); G4: 65,00(3,97); G5: 75,56(1,76); G6: 72,48(4,69). Os valores de ΔE também foram calculados (critérios do NBS). Conclusão: a resina composta, submetida ao clareamento, caseiro sofreu maior alteração de cor quando imerso em vinho tinto, comparado aos demais grupos.

Objective: to evaluate the effect of at-home and in-office bleaching on staining susceptibility of a resin composite with immersion in staining solutions. Thirty specimens of a microhybrid composite were first evaluated with a spectrophotometer (Vita Easyshade), and randomly divided into 6 groups: G1: no bleaching, immersion in coffee; G2: no bleaching, immersion in red wine; G3: bleaching with 10% carbamide peroxide (PC10%) and immersion in coffee; G4: bleaching with PC10% and immersion in wine; G5: bleaching with 35% hydrogen peroxide (PH35%) and immersion in coffee; G6: PH35% and immersion in wine. The final color was evaluated for all groups. Color change values (CIELab), by means of L values - luminosity - were evaluated and statistically analyzed by ANOVA and Tukey's post-test. Results: means(standard-deviation) for initial L values were: G1:88.22(1.62); G2:86.76(0.86); G3:82.52(2.90); G4:84.72(1.24); G5:85.64(1.92); G6:86.30(1.13), e final L values were: G1:78.32(2.24); G2:76.46(1.61); G3:74.60(0.92); G4:65.00(3.97); G5:75.56(1.76); G6:72.48(4.69). ΔE values were also calculated, according to NBS criteria. Conclusion: there was an increased staining susceptibility of the resin composite submitted to at-home bleaching when immersed in red wine, compared to the another groups, by means of luminosity.