Evaluation of different mechanical cleaning protocols associated with 2.5% sodium hypochlorite in the removal of residues from the post space.

Aims: This study evaluated the effectiveness of different mechanical protocols using rotary brush (RB), ultrasonic tip, and oscillatory system (OS) associated with 2.5% sodium hypochlorite (NaOCl) in the removal of residues and dentin permeability in the cervical and apical segments of the post space. Settings and Design: Experimental in vitro study. Methods: Forty roots from human first molars were prepared and divided into four groups according to the cleaning protocols: Control (CO), NaOCl 2.5% conventional irrigation with a syringe; RB associated with NaOCl 2.5%; ultrasonic tip (US) associated with NaOCl 2.5%; OS associated with NaOCl 2.5%. Statistical Analysis Used: The persistence of residues was evaluated by scanning electron microscopy and data submitted to Kruskal-Wallis and Dunn tests, and dentin permeability evaluated by confocal microscopy and date submitted to ANOVA one-way and Tukey's tests (P = 0.05). Results: There were no differences in residue cleaning among the CO, RB, US, and OS groups, regardless of the analyzed root segment (P > 0.05). When comparing groups, dentin permeability in the CO group was significantly lower in the cervical segment (P < 0.05). Conclusions: The OS group promoted the highest permeability value in the apical segment. RB, US, and OS are similar in removing residues from the post space. However, OS results in higher dentin permeability in the apical segment.

Effects of alpha-tocopherol antioxidant on fracture strength and adhesion of endodontically treated teeth restored after dental bleaching.

This study evaluated the effect of different concentrations of alpha-tocopherol in gel form on fracture strength, hybrid layer formation, and microtensile bond strength of endodontically treated teeth bleached with 40% hydrogen peroxide (H2 O2 ). Sixty bovine incisors were randomized into one of six groups (n = 10 incisors per group) defined by the interventions carried out after endodontic treatment. In the control group, no additional intervention was carried out, while all teeth in the five intervention groups were bleached with 40% H2 O2 and subsequently treated with alpha-tocopherol at concentrations of 15% (15AT), 20% (20AT), or 25% (25AT), with 10% sodium ascorbate (10SA), or with nothing (40HP). Fracture strength was evaluated in a mechanical testing machine, hybrid layer formation was assessed using scanning electron microscopy, and bond strength was determined using microtensile bond-strength testing. Data were analyzed using Kruskal-Wallis and Dunn's tests. No statistically significant difference regarding fracture strength was observed among groups. Hybrid layer formation was greater in the 15AT group than in groups 40HP and 10SA. Teeth in groups 15AT, 20AT, and 25AT demonstrated higher bond strength than teeth in groups 40HP and 10SA. Alpha-tocopherol, preferably at 15%, effectively reverses the deleterious effects, of bleaching, on hybrid layer formation and bond strength to dentin.

Fracture resistance and bonding performance after antioxidants pre-treatment in non-vital and bleached teeth.

This study aimed to evaluate the effect of antioxidant solutions on fracture strength and bonding performance in non-vital and bleached (38% hydrogen peroxide) teeth. One hundred and eighty dentin specimens were obtained, 60 for each test: fracture strength, hybrid layer thickness, and bond strength. The groups (n=10) were randomly composed according to post-bleaching protocol: REST - restoration, without bleaching; BL - bleaching + restoration; SA - bleaching, 10% sodium ascorbate solution, and restoration; AT - bleaching, 10% α-tocopherol solution, and restoration; CRAN - bleaching, 5% cranberry solution, and restoration; CAP - bleaching, 0.0025% capsaicin solution, and restoration. Data were analyzed with ANOVA, Kruskal-Wallis, Dunn, and Qui-Square tests (α=0.05). The highest fracture strength values were observed in REST (1508.96 ±148.15 N), without significant difference for the bleached groups (p>0.05), regardless of the antioxidant use. The hybrid layer thickness in the group that was not subjected to bleaching (REST) was significantly higher than in any other group. The bond strength in the bleached and antioxidants-treated groups (SA, AT, CRAN, CAP) has no differences with the bleached group without antioxidants (BL). Adhesive failures were predominant in the groups that did not receive the antioxidant application. In conclusion, the evaluated antioxidants did not show an effect on the fracture strength, hybrid layer thickness, or bond strength of dentin bleached after endodontic treatment. The application of 10% sodium ascorbate, 10% alpha-tocopherol, 5% cranberry, or 0.0025% capsaicin solutions is not an effective step and should not be considered for the restorative protocols after non-vital bleaching.

Effect of sodium hypochlorite-based formulations on the adhesion interface after fiber post cementation.

The study evaluated the persistence of residues, bond strength and tags formation of a cementation system after post-space irrigation with different sodium hypochlorite-based irrigants. The groups were divided according to the irrigation protocol (DW: distilled water; SHS: sodium hypochlorite solution; SHG: sodium hypochlorite gel; and, SHT: sodium hypochlorite with surfactant). Forty roots (n=10) were used to evaluate the persistence of residues by scanning electron microscopy. Other forty roots were used to the push-out bond strength test, failure mode and tag formation analyses. Non-parametric data were submitted to Kruskal Wallis and Dunn tests, while parametric data were evaluated by one-way ANOVA. No difference was observed in the persistence of residues. DW showed the highest bond strength and tag formation. Type 2 failure mode was the most frequent in the experimental groups. Compared to control, SHT showed the best performance, since less negative effects on adhesive interface was observed.

CLINICAL-THERAPEUTICAL MANAGEMENT OF EXPOSED PULP USING BIOACTIVE MATERIALS: TWO CASE REPORTS

Aims: This article present alternatives of bioactive materials use for direct pulp capping in immature teeth and for apexogenesis.Case report: Two case reports with the application of bioactive cementsare presented here: one in a tooth with pulp exposure and another with deep carious lesion, pulp exposure and open apex.Results: In both cases, the treatment was performed in one visit and a favorable clinical and radiographic follow-up was achieved.Conclusion: The use of bioactive materials ledto the formation of a dentin bridge and healing process in the pulp tissue exposure, without the need for conventional endodontic treatment

Fracture resistance and bonding performance after antioxidants pre-treatment in non-vital and bleached teeth

Abstract This study aimed to evaluate the effect of antioxidant solutions on fracture strength and bonding performance in non-vital and bleached (38% hydrogen peroxide) teeth. One hundred and eighty dentin specimens were obtained, 60 for each test: fracture strength, hybrid layer thickness, and bond strength. The groups (n=10) were randomly composed according to post-bleaching protocol: REST - restoration, without bleaching; BL - bleaching + restoration; SA - bleaching, 10% sodium ascorbate solution, and restoration; AT - bleaching, 10% α-tocopherol solution, and restoration; CRAN - bleaching, 5% cranberry solution, and restoration; CAP - bleaching, 0.0025% capsaicin solution, and restoration. Data were analyzed with ANOVA, Kruskal-Wallis, Dunn, and Qui-Square tests (α=0.05). The highest fracture strength values were observed in REST (1508.96 ±148.15 N), without significant difference for the bleached groups (p>0.05), regardless of the antioxidant use. The hybrid layer thickness in the group that was not subjected to bleaching (REST) was significantly higher than in any other group. The bond strength in the bleached and antioxidants-treated groups (SA, AT, CRAN, CAP) has no differences with the bleached group without antioxidants (BL). Adhesive failures were predominant in the groups that did not receive the antioxidant application. In conclusion, the evaluated antioxidants did not show an effect on the fracture strength, hybrid layer thickness, or bond strength of dentin bleached after endodontic treatment. The application of 10% sodium ascorbate, 10% alpha-tocopherol, 5% cranberry, or 0.0025% capsaicin solutions is not an effective step and should not be considered for the restorative protocols after non-vital bleaching.

Resumo Este estudo teve como objetivo avaliar o efeito de soluções antioxidantes na resistência à fratura e resistência de união em dentes tratados endodonticamente e clareados (38% de peróxido de hidrogênio). Cento e oitenta espécimes de dentina foram obtidos, 60 para cada teste: resistência à fratura, espessura da camada híbrida e resistência de união. Os grupos (n=10) foram compostos aleatoriamente de acordo com o protocolo pós-clareamento: REST - restauração, sem clareamento; BL - clareamento + restauração; SA - clareamento, solução de ascorbato de sódio a 10% e restauração; AT - clareamento, solução de α-tocoferol a 10% e restauração; CRAN - clareamento, solução de cranberry a 5% e restauração; CAP - clareamento, solução de capsaicina 0,0025% e restauração. Os dados foram analisados ​​com os testes ANOVA, Kruskal-Wallis, Dunn e Qui-Quadrado (α=0,05). Os maiores valores de resistência à fratura foram observados em REST (1508,96 ±148,15 N), sem diferença significativa para os grupos clareados (p>0,05), independente do uso de antioxidantes. A espessura da camada híbrida no grupo que não foi submetido ao clareamento (REST) foi significativamente maior do que em qualquer outro grupo. A resistência de união nos grupos clareado e tratado com antioxidantes (SA, AT, CRAN, CAP) não apresentou diferenças com o grupo branqueado sem antioxidantes (BL). As falhas adesivas foram predominantes nos grupos que não receberam a aplicação do antioxidante. Em conclusão, os antioxidantes avaliados não mostraram efeito sobre a resistência à fratura, espessura da camada híbrida ou resistência de união à dentina clareada após tratamento endodôntico. A aplicação de soluções de ascorbato de sódio 10%, alfa-tocoferol 10%, cranberry 5% ou capsaicina 0,0025% não é uma etapa eficaz e não deve ser considerada para os protocolos restauradores após clareamento não vital.

Effect of antioxidants after post-space irrigation on the adhesive interface of glass fiber post cementation.

OBJECTIVE: This study evaluated the effects of antioxidants, 10% sodium ascorbate (SA) or 20% alpha-tocopherol (AT), after post-space irrigation with 2.5% sodium hypochlorite +17% EDTA (SH) or 1% peracetic acid (PA) on the adhesive interface after glass fiber post cementation. MATERIALS AND METHODS: Sixty bovine roots were endodontically treated. After preparation, the post-space was irrigated with SH or PA followed or not by the use of antioxidants (SA or AT) (n = 10). Push-out bond strength test, failure mode, and dentin penetrability analysis using confocal laser microscope were performed in the cervical, middle, and apical thirds. Data from bond strength and dentinal penetrability were evaluated by one-way ANOVA and Tukey post hoc test (p < 0.05). RESULTS: SH showed the lowest bond strength regardless of the third (p < 0.05). In apical third, mixed failure was the most incident in all groups. Only in the cervical third of the post-space, SH-AT provided the greatest tag extension of the cementation system into dentin (p < 0.05). However, in the middle and apical thirds, SH-AT, SH-SA, and PA-SA provided the largest tag extensions (p < 0.05), but similar to each other (p > 0.05). CONCLUSIONS: The use of antioxidants only favored bond strength when SH was used and dentin penetrability of the adhesive and conventional resin cementation, regardless of the solution used to irrigate the post-space. CLINICAL SIGNIFICANCE: The use of antioxidants (10% sodium ascorbate and 20% alpha-tocopherol) after post-space irrigation with sodium hypochlorite appears to increase the bond strength favoring the glass fiber post-cementation.

Microstructural effect of different concentrations of hydrogen peroxide photoactivated with LED/laser.

BACKGROUND: The use of different concentrations of hydrogen peroxide (HP) photoactivated with LED/laser sources is common however, their influence on tooth structure is not yet fully elucidated. This study aimed to evaluate the pH, microhardness and surface roughness of different bleaching protocols photoactivated with LED/laser. METHODS: Forty bovine incisors were sectioned (7 × 7 × 2 mm) and randomized into four groups for analysis of pH (n = 5), microhardness and roughness (n = 10): HP35, HP6_L, HP15_L, HP35_L. The pH analysis was performed in the initial and final minute of the bleaching protocol. Microhardness and roughness were evaluated before and 7 days after the last bleaching session. Results were obtained from two-way ANOVA for repeated measures and Bonferroni post-test at a significance level of 5%. RESULTS: HP6_L showed higher pH and greater stability between the initial and final evaluations, while the other groups showed similar pH with reduced values in the intragroup evaluation. No differences between groups in microhardness and roughness evaluations were observed. CONCLUSIONS: Although HP6_L showed higher alkalinity and pH stability, none of the protocols reduced the microhardness and surface roughness of bovine enamel.

Violet LED associated with high concentration hydrogen peroxide: Effects on bleaching efficacy, pH, and temperature.

BACKGROUND: This study aimed to evaluate the bleaching efficacy, pH, and temperature of 35% hydrogen peroxide (HP) gel used alone or associated with violet LED. METHODS: Sixty bovine crowns were sectioned (5 × 5 × 2mm). After staining with black tea, the specimens were randomized into four groups (n = 10) according to the bleaching protocol: HP35R: 3 × 15 min 35% HP; HP35: 1 × 45 min 35% HP; HP35VR: 3 × 8min 35% HP + Violet LED; HP35V: 1 × 24 min + Violet LED. Two bleaching sessions were performed for all the groups. Color change was evaluated before, 24h after each session, 7 days and 15 days after the last session. The variables ∆E00 [CIEDE2000] and WID were used for color analysis. The pH variation (initial and final) and the temperature of the gel were recorded (n = 5). ANOVA two-way for repeated measures and Bonferroni post-test was used at a significance level of 5%. RESULTS: HP35VR and HP35V the most noticeable color change(p < 0.05). The final values of pH were lower than the initial ones, but with no difference between the groups (p > 0.05). Groups HP35VR and HP35V showed an increase in temperature in relation to HP35R (p < 0.05). CONCLUSIONS: Violet LED improved the bleaching efficacy of 35% HP in a time-saving manner without negatively affecting the pH and temperature of 35% HP. The renewal of HP did not influence the outcomes.

Bonding effects of cleaning protocols and time-point of acid etching on dentin impregnated with endodontic sealer.

Objectives: This study aimed to investigate the bonding effects of cleaning protocols on dentin impregnated with endodontic sealer residues using ethanol (E) or xylol (X). The effects of dentin acid etching immediately (I) or 7 days (P) after cleaning were also evaluated. For bonding to dentin, universal adhesive (Scotchbond Universal; 3M ESPE) was used. The persistence of sealer residues, hybrid layer formation and microshear bond strength were the performed analysis. Materials and Methods: One hundred and twenty bovine dentin specimens were allocated into 4 groups (n = 10): G1 (E+I); G2 (X+I); G3 (E+P); and G4 (X+P). The persistence of sealer residues was evaluated by SEM. Confocal laser scanning microscopy images were taken to measure the formed hybrid layer using the Image J program. For microshear bond strength, 4 resin composite cylinders were placed over the dentin after the cleaning protocols. ANOVA followed by Tukey test and Kruskal-Wallis followed by Dunn test were used for parametric and non-parametric data, respectively (α = 5%). Results: G2 and G4 groups showed a lower persistence of residues (p < 0.05) and thicker hybrid layer than the other groups (p < 0.05). No bond strength differences among all groups were observed (p > 0.05). Conclusions: Dentin cleaning using xylol, regardless of the time-point of acid etching, provided lower persistence of residues over the surface and thicker hybrid layer. However, the bond strength of the universal adhesive system in etch-and-rinse strategy was not influenced by the cleaning protocols or time-point of acid etching.

Clinical performance of 6% hydrogen peroxide containing TiO2N nanoparticles activated by LED in varying wavelengths-a randomized clinical trial.

This randomized, controlled, and double-blinded clinical trial evaluated the clinical performance of dental bleaching performed with 6% hydrogen peroxide containing TiO2-N nanoparticles exposed to blue and violet activation lights. Forty volunteers, selected according to the inclusion and exclusion criteria, were randomly distributed into four experimental groups (n = 10): 35% hydrogen peroxide (PH35)-control; 6% hydrogen peroxide (PH6) containing TiO2-N nanoparticles without light activation; PH6 activated with a blue LED (PH6A); and PH6 activated with a violet LED (PH6V). The three bleaching sessions consisted of 3 consecutive 16-min applications of the bleaching agent described for each group. The groups receiving LED activation were exposed to light intermittently every 1 min, with a total exposure time of 8 min in each application. Efficacy was determined by the color variation in the upper central incisors and canines, using reflectance spectroscopy analysis performed by a calibrated evaluator (ICC = 0.83). Tooth sensitivity was characterized according to the presence and intensity (SI) self-recorded in specific forms. The group treated with PH6V was as effective as the control group (PH35), whereas the groups PH6A and PH6 showed lower efficacy. Regardless of the activation, all groups treated with 6% hydrogen peroxide were less likely to cause sensitivity compared to the control group (PH35). The use pf PH6 activated by LED violet resulted in an effective and safe clinical protocol for in-office dental bleaching.Trial registration number: RBR-8pbydg; registration date: 08/29/2017.

Effect of the several epoxy resin-based sealer compositions on adhesion interface in radicular dentin after calcium hydroxide intracanal medication removal.

BACKGROUND: This study evaluated the effects of several epoxy resin-based sealer compositions (AHP, AH Plus; ADS, Adseal; SPL, Sealer Plus) on bond strength and intratubular dentin penetration of the endodontic obturation, in root canal previously treated with calcium hydroxide intracanal medication (CH) and removed by continuous ultrasonic irrigation (CUI). MATERIAL AND METHODS: Forty-five maxillary canines were prepared up to F5 (ProTaper system), filled with CH, coronally sealed, and stored at 37ºC. After 1 week, CH was removed using 2.5% sodium hypochlorite energized by CUI. The specimens were randomly distributed in three groups (n=15) and root canal obturated, according to epoxy-based resin sealer composition (AHP, ADS or SPL). The roots were transversally sectioned in cervical, middle, and apical thirds. In each radicular third, push out bond strength using universal machine and intratubular dentin using confocal laser scanning microscopy (CLSM) and Image J Program were evaluated. Bond strength and intratubular dentin penetration were statistically evaluated by ANOVA one-way and Tukey tests and Kruskal Wallis test, respectively (α = 0.05). RESULTS: In middle and apical thirds, AHP showed higher bond strength values (p<0.05), and ADS and SPL were similar each other (p>0.05). All epoxy resin-based sealers presented similar intratubular dentin penetration, independently of the radicular thirds (p>0.05). Cohesive and mixed failures were predominant in the cervical thirds. In the middle and apical thirds, AHP showed more cohesive type failures, while ADS and SPL showed more adhesive-type failures. CONCLUSIONS: AHP has the highest bond strength in middle and apical radicular thirds, after calcium hydroxide intracanal medication removal using continuous ultrasonic irrigation, although intratubular dentin infiltration being similar among epoxy resin-based sealer with several chemical composition. Key words:Continuous ultrasonic irrigation, endodontic sealers, epoxy resin-based sealers, root canal obturation.

Management of Tooth Discoloration after Orthognathic Surgery Complications: Report of Two Cases

ABSTRACT: Orthognathic surgery is performed for the correction of craniofacial discrepancies. However, complications, such as tooth discoloration are possible. This case report presents two patients who underwent bilateral sagittal split ramus osteotomy associated with segmental Le Fort I osteotomy and genioplasty. During surgeries, the apical region of anterior teeth was accidentally injured in both cases. After three-week surgery follow-up, the injured teeth showed a change in color to dark pink. In both teeth, the root canal treatment was performed followed by the non vital tooth bleaching. Three sessions were necessary to achieve a significant color change of the teeth. The two-year follow-up showed that both teeth preserved an acceptable color. It was concluded that tooth discoloration after orthognathic surgery is a possible complication, which could be overcome following a conservative approach. Additionally, patients should be informed preoperatively.

RESUMEN: La cirugía ortognática es comúnmente realizada para corregir las discrepancias cráneo-faciales. Sin embargo, se pueden producir complicaciones tales como la pigmentación dentaria. Este reporte de casos presenta a dos pacientes que fueron sometidos osteotomía sagital bilateral de la rama mandibular asociada a osteotomía segmentaria Le Fort I y genioplastía. Durante la fase quirúrgica, la región apical de dientes anteriores fueron accidentalmente dañados en ambos casos. Después de tres semanas de seguimiento de la cirugía, los dientes afectados mostraron un cambio de color a rosado oscuro. Se realizó el tratamiento de conductos seguido de aclaramiento interno en ambas piezas dentarias. Fueron necesarias tres sesiones para lograr un cambio de color significativo. El seguimiento de dos años mostró que ambos dientess conservaron un color aceptable. En conclusión, la pigmentación dentaria después de la cirugía ortognática es una posible complicación, sin embargo, puede ser tratada por medio de un enfoque conservador. Además, los pacientes deben ser informados antes de la cirugía.

Blue Covarine Toothpaste versus Office Whitening: Which is the Most Effective on Stained Teeth? / Creme Dental de Blue Covarine Versus Clareamento de Consultório: Qual é o Mais Efetivo em Dentes Pigmentados?

Alternative whitening strategies to hydrogen peroxide have been proposed, such as the inclusion of abrasive and/or pigmented particles in the toothpaste. This study compared the whitening effectiveness of a toothpaste containing Blue Covarine (BC) vs. an in-office whitening treatment using 35% hydrogen peroxide (HP) in teeth stained. Bovine incisors blocks (6.0x6.0x2.0 mm) were stained with green tea (GT), orange soda (OS), or red wine (RW). The samples were randomly assigned into 8 groups (n=15), according to the type of staining and whitening treatment: G1 ­ no staining, BC (Control); G2 ­ no staining, HP (Control); G3 ­ GT, BC; G4 ­ GT, HP; G5 ­ OS, BC; G6 ­ OS, HP; G7 ­ RW, BC; G8 ­ RW, HP. Color change (ΔE), luminosity (L*), green-red axis (a*), and blue-yellow axis (b*) were recorded with spectroscopy at T0 ­ baseline, T1 ­ immediately after toothbrushing or in office tooth whitening, and T2 ­ after the conclusion of the treatments. The whiteness index for dentistry (WID) was calculated. Data were analyzed by two-way repeated measured mixed ANOVA and Bonferroni test (α=0.05). HP showed a better whitening performance (ΔE) (p ≤ 0.042). Otherwise, no effects of the whitening agent were observed (p = 1.000). Data from ΔL, Δa, and Δb showed statistically significant differences for experimental groups (p < 0.001). In the WID analysis, BC and HP had similar effects within control and RW groups. In conclusion, blue covarine toothpaste may be a viable option for extrinsically stained teeth. However, for severe staining, HP-based whitening agents proved to be the most effective treatment strategy. (AU)

Estratégias de clareamento alternativas ao peróxido de hidrogênio têm sido propostas, como a inclusão de partículas abrasivas e/ou pigmentadas nos cremes dentais. Este estudo comparou a eficácia clareadora de um creme dental contendo Blue Covarine (BC) com um tratamento de clareamento em consultório com peróxido de hidrogênio a 35% (HP) em dentes pigmentados. Blocos de incisivos bovinos (6,0x6,0x2,0 mm) foram pigmentados com chá verde (GT), refrigerante de laranja (OS) ou vinho tinto (RW). As amostras foram distribuídas aleatoriamente em 8 grupos (n = 15), de acordo com o tipo de pigmento e tratamento clareador: G1 - sem coloração, CB (Controle); G2 - sem coloração, HP (Controle); G3 - GT, BC; G4 - GT, HP; G5 - OS, BC; G6 - SO, HP; G7 - RW, BC; G8 - RW, HP. Mudança de cor (ΔE), luminosidade (L *), eixo verde-vermelho (a*) e eixo azul-amarelo (b*) foram registrados com espectroscopia em T0 - baseline, T1 - imediatamente após a escovação ou clareamento dental em consultório, e T2 - após a conclusão dos tratamentos. O índice de brancura para odontologia (WID) foi calculado. Os dados foram analisados por ANOVA mista de duas vidas para medidas repetidas e teste de Bonferroni (α = 0,05). HP apresentou melhor desempenho de clareamento (ΔE) (p ≤ 0,042). Os dados de ΔL, Δa e Δb mostraram diferenças estatisticamente significativas para os grupos experimentais (p <0,001). Na análise WID, BC e HP tiveram efeitos semelhantes nos grupos controle e RW. Em conclusão, o creme dental covarine azul pode ser uma opção viável para dentes com coloração extrínseca. No entanto, para manchas graves, os agentes de clareamento à base de HP provaram ser a estratégia de tratamento mais eficaz. (AU)

Effect of post-space irrigation with acid solutions on bond strength and dentin penetrability using a self-adhesive cementation system.

BACKGROUND: The aim of this study was to evaluate the effects of surface treatments with 1% peracetic acid (PA), solution containing 17% EDTA (SmearClear, Kerr Endodontics), solution containing a combination of 17% EDTA with 2% chlorhexidine (QMix, Dentsply Sirona) on the post-space root dentin compared to 2.5% sodium hypochlorite (NaOCl) on bond strength and resin tags length in dentin. MATERIAL AND METHODS: Forty human-canine roots were endodontically treated and the post space was prepared. The specimens were randomised into four groups (n = 10): control - irrigation with 2.5% NaOCl solution, PA - irrigation with 1% PA, SmearClear - irrigation with SmearClear solution, and QMix - irrigation with QMix solution. The fibre posts were cemented using a self-adhesive resin system (Relyx U200, 3M ESPE). After six months, the specimens were cross-sectioned and subjected to push-out and confocal laser microscopy tests. One-way ANOVA and Tukey's tests were used to analyse the data (α= 0.05). RESULTS: PA and QMix presented the highest bond strength values compared to the other groups (p< 0.05). There was no significant difference between the resin tags length in dentin by the groups (p = 0.75). CONCLUSIONS: Irrigation of the post space with 1% PA and QMix showed a positive clinical impact on the adhesion between the fiber post and root dentin. However, these materials had no influence on resin tags length in dentin by self-adhesive resin cement. Key words:Fiber post, adhesive cementation, self-adhesive resin cement, root dentin, irrigating solutions.

Evaluation of various methods of methylene blue removal from the post space after photodynamic therapy on the bonding interface using different resin cementation systems.

BACKGROUND: To evaluate the effects of three protocols for removing 0.01 % methylene blue from the post space after photodynamic therapy on bond strength and tag formation in the dentin of the fiber post space, using a conventional cementation system with an etch-and-rinse or universal adhesive system. METHODS: Sixty human canines were endodontically treated for fiber post cementation. The specimens were randomized into 6 groups (n = 10): G1, G2, G3, G4, G5, and G6. The G1, G2, and G3 groups were irrigated with saline solution, 2.5 % sodium hypochlorite (NaOCl), and 2.5 % NaOCl, agitated by passive ultrasonic irrigation (PUI), respectively. In these groups, a conventional cementation system with etch-and-rinse adhesive was used. The G4, G5, and G6 groups were irrigated with the respective solutions mentioned above and cemented using a conventional cementation system with universal adhesive. Tag formation in the dentin was evaluated by confocal laser scanning microscopy. The push-out bond strength test was performed on three thirds of the specimens. RESULTS: In the cervical and middle thirds, the greatest extent of dentin tag formation occurred in the G1 (p = 0.023 and p = 0.033, respectively). In the apical third, G1, G2, and G3 demonstrated similar tag formation between themselves (p = 0.089). In the cervical and middle thirds, G4 demonstrated the highest bond strength when compared to the other groups (p < 0.05). CONCLUSION: The protocols for removing 0.01 % methylene blue with NaOCl, irrespective of the involvement of passive ultrasonic irrigation, negatively effects the bond strength and tag formation in the dentin of the post space.

Resistência flexural e adaptação marginal dos materiais restauradores provisórios utilizados em dentes tratados endodonticamente / Flexural strength and marginal adaptation of temporary restorative materials used in endodontically treated teeth

Avaliar a resistência flexural e a adaptação marginal dos materiais restauradores provisórios Clip F (CF),Bifix Temp (BT), Systemp.onlay (SO), Fill Magic Tempo (FT) e Provi Master F (PF), na dentina da coroa dentária de dentes tratados endodonticamente. Métodos: Inicial-mente, foram confeccionados dez espécimes de cada um dos materiais restauradores, que foram individualmente submetidos ao teste de resistência flexural, na máquina de ensaio eletromecânica. Para avaliar a adaptação marginal,a câmara pulpar de cinquenta pré-molares superiores foi restaurada com um dos materiais avaliados (n=10). Após sete dias, a interface entre a dentina e o material restaurador, no terço médio da coroa dentária, foi submetida à análise em microscopia eletrônica de varredura. A extensão de desadaptação dos materiais e os gaps formados com a dentina foram mensurados com o software Image J.Resultados: CF e BT demonstraram o maior e o menor valor de resistência flexural, respectivamente (p<0,05).Os valores demonstrados por SO, FT e PF foram similares entre si (p>0,05). Por outro lado, CF demonstrou a menor extensão de desadaptação marginal (em porcentagem)e extensão de gaps (em µm) (p<0,05) na interface com a dentina. BT apresentou valor intermediário, mas menor do que os dos SO, FT e PF (p<0,05) que, por sua vez, foram similares entre si (p>0,05). Conclusões: O CF demonstrou o maior índice de resistência flexural e menor extensão de desadaptação marginal e gaps, em comparação aos demais materiais restauradores provisórios (AU).

Objectve: This study evaluated the flexural strength and marginal adaptation of Clip F (CF), Bifix Temp (BT), Systemp.onlay (SO), Fill Magic Tempo (FT) and Provi Master F (PF) in endodontically-treated coronal dentin. Methods: Firstly, ten specimens of each restorative material were prepared, and submitted to flexural strength test using eletromechanical testing machine. Then, the pulp chamber of 50 maxillary premolar were restored using one of the provisional restorative materials (n = 10) in order to evaluate the marginal desadaptation extension. After 7 days, the interface between dentin and temporary restorative material, in crown middle third, was subjected to scanning electron microscopy (500X). Marginal desadaptation and gaps extensions in dentin-temporary restorations interface were measured using Image J software. Results: CF and BT presented the highest and the lowest flexural strength values, respectively (p <0.05). SO, FT and PF showed similar values (p> 0.05). In relation to marginal desadaptation (%) and gap extensions (µm), CF presented the lowest marginal desadaptation and gaps incidence values (p < 0.05). BT showed intermediate values, but lower than SO, FT e PF (p < 0.05), which were similar among them (p > 0.05). Conclusion: CF presented the best flexural strength and the lowest marginal desadaptation and gaps extension (AU).

Whitening toothpaste containing activated charcoal, blue covarine, hydrogen peroxide or microbeads: which one is the most effective?

The efficacy of whitening toothpastes is questionable and controversial. Clinicians, patients and researchers have expressed concern with whitening toothpastes due to the risk of wearing the dental structure and the potential for disappointment if the advertised cosmetic results are not achieved. OBJECTIVE: This study compared the whitening performance of toothpastes with different whitening technologies after initial and continued use. MATERIAL AND METHODS: Ninety bovine incisors were stained using a concentrated solution of black tea. They were randomly distributed into 6 groups, according to the toothpaste whitening technology: activated charcoal (B&W), blue covarine (WAD), hydrogen peroxide (LWA), microbeads (Oral B 3D White Perfection - 3DW) and optimized abrasives (XW4D). They were compared to a traditional toothpaste without a whitening agent (TA - control). Specimens underwent a brushing machine with controlled pressure, time and temperature. A calibrated examiner measured the color using a VITA-Classical scale before the first brushing cycle (T0), after the first brushing cycle (TI), and after a brushing cycle that simulates continuous use (TCU). Whitening performance was evaluated by the difference of shades (ΔSGU) between T0-TI and T0-TCU timepoints, using the Kruskal-Wallis and Dunn's non-parametric test. The Wilcoxon test was used to evaluate the cumulative effect (α=0.05). RESULTS: Statistically significant differences were observed between toothpastes in both TI and TCU (p<0.05). The time of use also had a significant effect (p<0.05). CONCLUSION: Only WAD and 3DW showed whitening performance after the first use (TI). The greatest whitening performance after continuous use was obtained by WAD, followed by LWA and 3DW. The use of conventional toothpaste (TA) promotes no tooth whitening. CLINICAL RELEVANCE: Microbead abrasives (3DW) and blue covarine (WAD) were the active technology tested that presented the best global tooth whitening performance.

Evaluation of calcium release and pH value of light-cured cavity liners for pulp-capping materials / Avaliação da liberação de cálcio e alteração de pH de forradores cavitários fotoativados para capeamento pulpar

Introduction: Cavity liners based calcium hydroxide present low strength and high solubility that is consider a disadvantage. In order to enhance these properties it was developed a light-cured cavity liner based calcium hydroxide containing resin. Objective: The purpose of this study was to evaluate the pH and calcium release of light-cured cavity liners. Material and method: There were prepared specimens (n=10) with the Ultra-Blend ® plus, Biocal® (light cured cements) and Hydro C® (control). The samples were stored in 10 mL of distilled water and maintained at 37 °C. After 24 hours, 7, and 14 days, there were analyzed pH and the release of calcium levels. The data were statistically analyzed by ANOVA and Tukey test (α = 0.05). Result: The results of pH showed Hydro C > Ultra-Blend plus > Biocal. Biocal presented worst calcium release. Conclusion: Light-cured materials present lower calcium release and alteration in pH values.

Introdução: Forradores cavitários à base de hidróxido de cálcio apresentam baixa resistência e alta solubilidade. Para resolver este problema, foi desenvolvido forradores à base de hidróxido de cálcio fotoativáveis contendo resina para melhorar suas propridades. Objetivo: A proposta deste estudo foi avaliar a alteração de pH e liberação de cálcio de forradores fotoativáveis. Material e método: Foram preparadas amostras (n=10) com Ultra-Blend® plus, Biocal ® (cimentos fotoativáveis) e Hydro C® (controle). As amostras foram armazenadas com 10 mL de água destilada e mantidas em estufa à 37 °C. Depois de 24 horas, 7 e 14 dias, foram avaliados os níveis de liberação de cálcio e a alteração de pH. Os dados foram analisados estatisticamente pelo teste ANOVA, seguido do pós teste Tukey (α = 0.05). Resultado: Os resultados de pH mostraram Hydro C > Ultra-Blend plus > Biocal. Biocal apresentou a pior liberação de cálcio. Conclusão: Materiais fotoativados apresentam menor liberação de cálcio e alteração nos valores de pH.

Clinical effectiveness of fluorescence, digital images and ICDAS for detecting occlusal caries / Efetividade clínica da fluorescência, imagens digitais e ICDAS na detecção de cárie oclusal

Introduction: The detection of small caries lesions is still a challenge for dental professionals who in their clinical practice have a wide variety of methods to detect caries on occlusal surfaces. Objective: To clinically assess the effectiveness of the Vista Proof fluorescence camera, the Vista Cam digital intraoral micro camera and the International Caries Detection and Assessment System (ICDAS) visual criterion for detecting caries lesions on occlusal surfaces of permanent teeth. Material and method: One hundred and seven posterior teeth from adult patients were examined visually and by means of digital radiographs by an examiner who rated them according to the presence or absence of occlusal caries. The teeth were then assessed by the other examiner using ICDAS, fluorescence and magnified digital images. The effectiveness of the methods was measured based on sensitivity, specificity, positive and negative likelihood ratio. For each method, the Receiver Operating Characteristic (ROC) curve and the Area Under the ROC curve (AUROC) were estimated. Result: There was exceptional discrimination capacity for the intraoral images (AUROC=.93) and the ICDAS (AUROC=.91), with no significant statistical difference between them (z=.35, p=.73). The fluorescence exhibited an acceptable discrimination capacity (AUROC=0.78), although it was lower than the others. The positive likelihood ratio for the fluorescence was only 2.32, compared to 20.58 for the intraoral image and 58.11 for the ICDAS. Conclusion: Both methods and the ICDAS exhibited an adequate clinical performance, although the ICDAS and intraoral image were more effective than the fluorescence.

Introdução: A detecção de pequenas lesões de cárie ainda é um desafio para profissionais da Odontologia, que em sua prática clínica dispõem de uma grande variedade de métodos para detectar cáries nas superfícies oclusais. Objetivo: Avaliar clinicamente a efetividade da câmera de fluorescência Vista Proof, da microcâmera intraoral digital Vista Cam e do critério visual ICDAS (International Caries Detection and Assessment System) para detecção de lesões de cárie nas superfícies oclusais. Material e método: Cento e sete dentes posteriores de pacientes adultos foram examinados visualmente e por meio de radiografias digitais por um examinador que os classificou de acordo com a presença ou ausência de cárie. Os dentes foram então avaliados por outro examinador que utilizou o ICDAS, fluorescência e imagens digitais ampliadas. A efetividade dos métodos foi mensurada por meio da sensibilidade, especificidade, razão de verossimilhança positiva e negativa. Para cada método, a curva ROC (Receiver Operating Characteristic) e a área sob a mesma - AUROC (Area Under the ROC curve) foram estimadas. Resultado: Houve excepcional capacidade discriminante para as imagens intraorais (AUROC=0,93) e para o ICDAS (AUROC=0,91), com diferença estatística não significativa entre eles (z=0,35, p=0,73). A fluorescência apresentou capacidade discriminante aceitável (AUROC=0,78), embora tenha sido menor que os outros. A razão de verossimilhança positiva para a fluorescência foi 2,32, comparado a 20,58 para a imagem intraoral e 58,11 para o ICDAS. Conclusão: Ambos os métodos e o ICDAS exibiram um adequado desempenho clínico, sendo que o ICDAS e a imagem intraoral foram mais efetivos que a fluorescência.