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This study evaluated the effect of aging and cementation of fiber posts using glass ionomer and resin cements on push-out bond strength, failure mode, and resin tag formation. One hundred and twenty bovine incisors were used. After post-space preparation, the specimens were randomly allocated into 12 groups (n = 10) according to the cementation system used: GC - GC Gold Label Luting & Lining); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200 and the aging periods (24 hours, 6 months, and 12 months). Slices from the cervical, middle, and apical thirds were obtained and analyzed by push-out bond strength test and confocal laser scanning microscopy. One-way ANOVA and Tukey’s post-hoc test was used at a significance level of 5%. For the push-out bond strength test, no differences among GC, RU, and MC in the cervical and middle thirds were observed, regardless of the period of storage (P > 0.05). In the apical third, GC and RU showed similar bond strength but higher than other groups (P > 0.05). After 12 months, GC showed the highest bond strength (P < 0.05). Bond strength to post-space dentin decreased over time, regardless of the cementation system used. Cohesive failure was the most frequent, regardless of the period of storage, cementation system, and post-space third. Tag formation was similar among all groups. After 12 months, GC showed the highest bond strength values.

Aim To evaluate the flow, pH and calcium release of white MTA (WMTA), salicylate-based resin root canal sealer (Sealapex; SEAL) and SEAL containing 10 (SE10) or 20% (SE20) (w/w) of MTA. Methodology Flow test was realized according to ISO 6876 specification. The sealers samples (n= 10) were placed in polyethylene tubes and immersed in deionized water. After 24 hours and 7, 14, and 28 days, the water pH was determined with a pH meter, and calcium release was assessed by atomic absorption spectrophotometry. Results SEAL and WMTA showed respectively the highest and lowest flow rate when compared with the other materials (P0.05). In all periods, WMTA and SEAL respectively showed the highest and lowest calcium release (p

Made available in DSpace on 2022-05-01T13:41:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 The aim of this study was to evaluate the effects of cleaning protocols on the presence of residues, open dentinal tubules, and bond strength of a self-etch adhesive plus a dual-cure resin cement to dentin in the fiber-post space. The methods for cleaning utilized were conventional irrigation (CI), rotary brush with continuous rotary movement (RB), and continuous ultrasonic irrigation (CUI). Sixty bovine incisors were used for fiber-post space preparation. Thirty roots were divided into three groups (n = 10) according to the cleaning protocols and submitted to scanning electron microscope to evaluate presence of residues and relative quantity of open dentinal tubules on dentin surface. Similar protocols were performed in the other thirty roots (n = 10) using a self-etching adhesive system (Scotchbond Universal) and a dual-cure resin cement (Relyx Unicem 2). After 6 months cervical, middle, and apical thirds sections of fiber-post space were submitted to push-out testing. To data ANOVA and Tukey's test were employed (α = 5%). RB and CUI showed the lowest presence of residues on dentin surface (p =.015) and the highest bond strength values (p

Made available in DSpace on 2022-05-01T11:07:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Adhesive strategies were evaluated on the bond strength of bi-functional monomers bonded to endodontically-treated-dentin (ETD). Superficial dentin was removed on human molars. Teeth were immersed in 5 mL 2.5% NaOCl, followed by immersion in 5 mL 17% EDTA. Dentin surface impregnated with epoxy resin-based sealer was then divided four groups (n=10): Scotchbond Multi-Purpose (SBMP); Single Bond Universal (SBU); Optibond All-in-One (OPB); and Tetric-N-Bond Universal (TBU). After 24-h or 1-year-of-storage specimens were submitted to microtensile bond strength (µTBS) and failure classification. A confocal laser scanning microscope (CLSM) evaluated the hybrid layer formation. Two-way ANOVA and Tukey-HSD test were performed (α=5%). The µTBS did not present statistical differences among adhesive strategies after 24-h. Significant differences were found after 1-year-of-storage. CLSM analysis showed water infiltration and consequently degradation of the hybrid layer after 1-year-of-storage. The use of SBU universal adhesive on the self-etching mode on ETD produced more stable bond over the 1-year-of-storage. Department of Restorative Dentistry School of Dentistry São Paulo State University (UNESP), Rua Humaitá 1680 Department of General Dentistry School of Dental Medicine East Carolina University, 1851 MacGregor Downs Rd Division of Restorative and Prosthetic Dentistry College of Dentistry The Ohio State University, 305 W 12th Ave Department of Restorative Dentistry School of Dentistry São Paulo State University (UNESP), Rua Humaitá 1680 CAPES: 001

Recent formulations of resin-based composites have incorporated different combinations of materials. However, the mechanical and bonding behavior of these materials with intraradicular posts are unclear. This study aimed to evaluate the effect of light-cure and dual-cure resin composite posts on the fracture resistance of endodontically-treated teeth. Materials and Methods: Ninety extracted human upper canines were selected and randomly divided into nine groups (n=10): (G1) endodontically treated teeth without endodontic posts; (G2) glass-fiber post cemented with glass-ionomer cement; (G3) endodontic post by dual-cure composite resin (Rebilda DC); (G4) endodontic post by dual-cure composite resin (Cosmecore); (G5) endodontic post by dual-cure composite resin (Bis-Core); (G6) endodontic post by light-cure composite resin; (G7) glass-fiber post customized with flowable composite resin; (G8) glass-fiber post cemented with light-cure composite resin; (G9) glass-fiber post cemented with self-adhesive resin cement. After the post insertion, all specimens were subjected to mechanical (250,000 cycles) and thermocycling (6000 cycles, 5 °C/55 °C) and immediate loading at 45 degrees in a universal testing machine until fracture. The data were analyzed by one-way ANOVA and multiple comparisons using the Fisher LSD Method (p < 0 05). Results: The mean failure loads (±SD) for the groups ranged from 100.7 ± 22.6 N to 221.9 ± 48.9 N. The G1 group (without endodontic posts) had a higher fracture strength than all experimental groups (p < 0.001). Conclusions: Within the limitations, the light- and dual-cure post technique did not present lower fracture resistance values as compared to the conventional glass-fiber post.

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.

Resin-based composites (RBCs) have transformed restorative dentistry and its procedures. However, the characteristics of RBCs have been modified over the years to enhance the physical and chemical properties of the materials. This context raises the need for studies that evaluate whether the properties of the RBCs that are commercially available are clinically adequate with different curing modes. This study aimed to evaluate the mechanical behavior of commercial RBCs after undergoing different curing modes. Twenty-three RBCs of different classes were evaluated. For curing the specimens, a microwave (BMS45, Brastemp) (for 3 min at 450 W) and three LED units were used: an Emitter A Fit (Schuster (second generation)) (light-curing for 15 s with an irradiance of 1250 mW/cm2), VALO (Ultradent (third generation)) (light-curing for 15 s with an irradiance of 1100 mW/cm2), and Emitter Now Duo (Schuster (second generation)) (light-curing for 15 s with an irradiance of 1100 mW/cm2). A total of 670 RBC specimens of 8 mm in diameter and 1 mm in depth were obtained. Afterward, a biaxial flexure strength test was performed until the failure of the specimens, using a universal testing machine set at a speed of 0.5 mm/min. The same specimens were subjected to infrared spectroscopy for evaluating the degree of conversion. Tukey’s test was used for multiple comparisons at a significance level of 5%. The light-curing mode did not affect the flexure strength of the RBCs (p > 0.05), but the type and shade of RBCs did so (p < 0.05). In conclusion, the type of RBC directly interferes with the mechanical behavior of the material. However, the curing modes within the same RBC did not change the mechanical properties.

To evaluate the cleaning potential of 95% ethanol, acetone, and amyl acetate solutions used solely or in association, to remove epoxy resin-based sealer residues from pulp chamber dentin and their microstructural effects.One hundred and eighty bovine incisor specimens were divided into nine groups according to the cleaning protocol: ET (ethanol); AC (acetone); AA (amyl acetate); E1: AA+AC; E2: AA+ET; E3: AC+ET; E4: AA+AC+ET; PC (positive control), and NC (negative control). All groups were impregnated with epoxy resin-sealer, except NC. Ninety specimens were divided into groups (n = 10) for evaluation of persistence of residues and amount of open dentinal tubules by SEM analysis and evaluation of chemical compounds on the dentin surface after cleaning with electron dispersive spectroscopy. The others 90 specimens were submitted to Knoop microhardness evaluation. Persistence of residues data were submitted to the Kruskal Wallis and Dunn tests (α = 0.05). Open dentinal tubules and microhardness data were submitted to one-way ANOVA and Mann Whitney tests (α = 0.05).AA and E4 protocols showed the lowest persistence of residues. E4 group had the highest incidence of open dentinal tubules. E3 and E4 groups showed no changes in the atomic ratio Ca/P, which was similar to NC group. E4 group did not present W, an element presents in all the other groups. ET and E4 protocols showed the smallest reduction in dentin microhardness.The combination of amyl acetate, acetone and ethanol is the most effective and safe protocol to remove epoxy sealer residues on pulp chamber dentin. Moreover, it has the lowest microhardness reduction.The combined use of amyl acetate, acetone, and ethanol enhanced the cleaning of pulp chamber dentin with minimal microstructural damage.

Introdução: A indicação das soluções anestésicas nos tratamentos endodônticos de rotina deve estar fundamentada nos conhecimentos dos possíveis efeitos que essas substâncias podem desencadear no paciente sistemicamente comprometido. Objetivo: O objetivo do presente estudo foi priorizar a indicação e discutir os possíveis efeitos secundários ou adversos passíveis de ocorrência com as substâncias que compõem as soluções anestésicas durante a rotina de tratamento dos canais radiculares.

Made available in DSpace on 2022-04-28T17:22:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Objective: To evaluate the effects of mechanical versus chemical cleaning protocols for cleaning the root dentin surface before cementation of fiberglass posts for their effect on the bond strength, failure mode, and dentinal penetration of the cementing agent using an etch-and-rinse adhesive system on dentin prepared to receive a fiberglass post. Methods: Forty roots of bovine teeth were endodontically treated and prepared for fiber post cementation. The specimens were randomized into 4 groups of 10: Control group (CO) - irrigation with 2.5% NaOCl; DW group- irrigation with distilled water; RB group - rotating brush for cleaning root canals, and CUI group - continuous ultrasonic irrigation. The fiberglass posts were cemented, and the specimens were immersed in distilled water for 6 months. A push-out test was performed on the cervical, middle, and apical thirds of the samples. Dentinal penetration of the cementing agent and the fracture pattern were evaluated by laser confocal microscopy. Statistical analysis was performed using analysis of variance (ANOVA) and post hoc Tukey tests (alpha=0.05). Results: The RB and CUI groups showed significantly higher bond strength values when compared to the Control and DW groups (p

Made available in DSpace on 2021-06-25T10:59:20Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 This study evaluated the persistence of eugenol-containing (PR, Provy) or eugenol-free (RT, Relyx Temp, and TB, Temp Bond) temporary cement residues and its effects on push-out bond strength and dentinal penetration of the self-adhesive resin cement (Relyx U200). Eighty human roots were endodontically treated and post space prepared. Fourty specimens were distributed in four groups (n = 10): Control (CO), without any clinical procedure, PR, RT, and TB, where a metallic post was cemented with one of the temporary cements. After metallic post removal, hemi sections post space were submitted to SEM analysis. Another specimens were distributed in similar groups, but fiberglass post was cemented using Relyx U200 cement and submitted to push-out bond strength and dentinal penetration cement analysis, in post space thirds. SEM analysis were evaluated by Kruskal–Wallis and Dunn tests, while bond strength and dentinal penetration were evaluated by ANOVA One-Way and Tukey test (p

Made available in DSpace on 2022-04-29T08:40:52Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-03-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) EDTA solution removes smear layers; this function is more effective when the solution is agitated. The purpose of this study was to evaluate the protocol application of two diode lasers, compared with conventional energization or ultrasonic energization of 17% EDTA, evaluating the EDTA and AH Plus penetration capacity with laser confocal microscopy and push-out strength. In this study, human extracted teeth were used. The crowns were removed, and the root canal was prepared with a ProTaper system until the F5 file is reached, and irrigated with 2.5% sodium hypochlorite. The roots were randomly distributed in 5 groups (n=10): group control—flood with EDTA; conventional—flood with EDTA and agitation with K#45; ultrasonic—ultrasonic EDTA energization, TheraLase—EDTA energized with diode laser TheraLase surgery (808 nm, 2.8 W, pulsed mode, 20 Hz); and Gemini—EDTA energized with diode laser Gemini (810–980 nm, 2 W, pulsed mode, 50 Hz). The roots were obturated, using the single-cone technique and AH Plus. The EDTA solution was added with Malachite Green and AH Plus with Rhodamine B for evaluation with a laser confocal microscope. Specimens were sectioned in slices, one slice per third root, used in a laser confocal microscope and push-out strength. The data were submitted to normality test, analyzed using the Kruskal-Wallis test followed by Dun test, with a 5% level of significance (P < 0.05). The penetrability of EDTA and AH Plus was statistically different between the Ultrasonic, TheraLase, and Gemini groups when compared with other groups. However, when comparing ultrasonic with TheraLase and Gemini, there was no significant difference. In a push-out strength test, there was no significant difference, and the cohesive failures were predominant. In conclusion, the energization of 17% EDTA with any of the diode lasers improved only the penetrability of EDTA and AH Plus. Department of Restorative Dentistry Araraquara Dental School São Paulo State University (UNESP), Rua Humaitá, 1680, SP Department of Restorative Dentistry Araraquara Dental School São Paulo State University (UNESP), Rua Humaitá, 1680, SP CNPq: 167248/2018-9

Bleaching protocols using low concentration hydrogen peroxide (HP) photoactivated with LED sources have been widely discussed. Herein, we evaluated the whitening efficacy of 15% HP photoactivated with blue or violet LED compared to 35% HP.Thirty bovine crowns were sectioned into 5 × 5 × 2 mm specimens. After staining in black tea, the specimens were randomized into three groups (n = 10): 35% HP, 15% HP + blue LED and 15% HP + violet LED. Two bleaching sessions were performed and the color assessment (∆L*, ∆a*, ∆b*, ∆EAll groups showed effective and similar results over 1 month of follow-up (p 0.05), with only intragroup differences among the time intervals (p 0.05).The use of 15% HP photoactivated with blue or violet LED showed similar whitening efficacy compared to 35% HP. Thus, the association of low concentration bleaching gels with blue or violet LED sources can provide successful and less-aggressive treatment in terms of color change.

Made available in DSpace on 2022-04-29T08:29:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-01 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 (a= 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. Department of Restorative Dentistry Araraquara School of Dentistry São Paulo State University (UNESP) School of Dentistry Federal University of Para (UFPA) Department of Restorative Dentistry Bauru School of Dentistry University of Sao Paulo (USP) Department of Restorative Dentistry Araraquara School of Dentistry São Paulo State University (UNESP)

Made available in DSpace on 2021-06-25T10:35:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-09-01 Aim: The aim of this study to evaluate the effects of 10% alpha-tocopherol (10AT) or 20% alpha-tocopherol (20AT) incorporation on biological compatibility, pH, and calcium release of calcium hydroxide (CH) paste associated with 2% chlorhexidine digluconate (CHX). Materials and Methods: Four groups were evaluated: CH, CH-CHX, CH-CHX-10AT, and CH-CHX-20AT. For biological compatibility test, polyethylene tubes containing several pastes were implanted in Wistar rats' subcutaneous tissue (n = 28). After 48 h and 7, 14, and 21 days postimplantation, the specimens were removed and subjected to histologic and histomorphometric analysis. The number of inflammatory cells was evaluated. For pH and calcium release analysis, the pastes were placed individually (n = 10) in plastic tubes and immersed in deionized water. The calcium release and pH changes were evaluated in 24 and 48 h and 7, 14, and 21 days. All data were submitted to Kruskal-Wallis test (α = 0.05). Results: Concerning biological compatibility, all materials shown a similar decidual response (P > 0.05). In the first hours, there was as increase in the number of inflammatory cells, inducing an expressive inflammatory response. After 14 days, inflammation reaction decreased and collagen fiber was organized for the tested pastes (P = 0.05). The pH analysis of the groups maintained the same relationship during the different periods evaluated: the CH and CH-CHX groups showed higher values and were similar to each other (P > 0.05), followed by the CH-CHX-10AT and CH-CHX-20 AT groups. Regarding the amount of calcium ions, in the initial (24 hours) and final (21 days) periods, the groups did not present differences between them (P > 0.05). Conclusion: The 10AT or 20AT, as an antioxidant agent, incorporation to CH and 2% CHX paste negatively affected biological and physicochemical properties. Department of Restorative Dentistry School of Dentistry Araraquara Sao Paulo State University - UNESP Department of Basic Sciences Araçatuba Dental School Sao Paulo State University - UNESP Department of Restorative Dentistry School of Dentistry Araraquara Sao Paulo State University - UNESP Department of Basic Sciences Araçatuba Dental School Sao Paulo State University - UNESP

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 (p0,05). Por outro lado, CF demonstrou a menor extensão de desadaptação marginal (em porcentagem)e extensão de gaps (em μm) (p0,05). 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.

O presente artigo descreve um caso incomum de canino superior direito com duas raízes. Esse é o quarto caso relatado na literatura. Paciente do sexo feminino, 66 anos de idade, foi encaminhada para tratamento endodôntico do dente #13. A avaliação clínica mostrou que o dente #13 não apresentava resposta após o teste de vitalidade. Radiografias foram realizadas e revelaram que o dente #13 apresentava duas raízes. Em seguida, a paciente foi submetida a tratamento endodôntico. Esse relato de caso é relevante porque descreve uma variação anatômica rara, mas que pode se apresentar na clínica. Por tal motivo, o dentista precisa ter domínio da anatomia normal dos dentes para realizar corretamente o tratamento endodôntico, assim como conhecer as possíveis variações anatômicas, e analisar minuciosamente a radiografia de diagnóstico para ter uma noção individualizada da anatomia do dente a tratar.

The aim of this study was to evaluate the effectiveness of cleansing protocols to remove sealer residues using different cleaning strategies and the effect of bond strength of two universal adhesives to dentin impregnated with epoxy resin-based sealer.Fifty bovine dentin specimens were impregnated with epoxy resin-based sealer containing calcium hydroxide (Sealer Plus) and submitted to cleansing protocols (n = 10): negative control (NC), positive control (PC), 95% ethanol (ET), xylol (XI), and amyl acetate (AA). Specimens were evaluated by scanning electron microscope (SEM). Other 100 specimens were submitted to the same protocols (n = 20). Each protocol was divided into subgroups (n = 10) according to the universal adhesive system used: Scotchbond Universal (SU); Ambar Universal (AU). Bond strength was evaluated by micro-shear bond test (μSBT). Persistence of residues data were assessed with Kruskal-Wallis and Dunn's tests. μSBT data were analyzed with two-way ANOVA (α = 5%).ET presented higher persistence of residues compared to AA and XI (p 0.05). AA and XI were similar from each other (p 0.05). AU and SU presented similar μSBT values, regardless of the cleansing solution (p 0.05). SU-NC presented the highest μSBT among all conditions (p 0.05).The bond strength of universal adhesives was not affected by different amounts of sealer residues after different cleaning protocols.Non-polar substances such as amyl acetate and xylol are effective for removing residues from epoxy resin-based endodontic sealers.

This study evaluated the effect of irrigation protocols using 95% ethanol (ET) or 1% peracetic acid (PA) prior the use of 2% chlorhexidine (CHX) compared to distilled water (DW) on the chemical smear layer (CSL) formation and incidence of open dentin tubules at the apical, medium, and cervical third of the post-space dentin. Scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS) images were used. Forty bovine roots were endodontically treated. After, post-space preparation was performed and the roots were randomized in four groups (n = 10) according to the irrigation protocol: DW, CHX, CHX-ET and CHX-PA. The chemical composition of CSL and the incidence of open dentin tubules at the post-space thirds were evaluated by EDS (500× magnification) and SEM (2000× magnification) images, respectively. Data from chemical composition of CSL were descriptively analyzed, while the incidence of open dentin tubules was evaluated by scores and submitted to Kruskal-Wallis and Dunn test (p = .05). Cl, Bi, and Si were the chemical elements most found over the dentin after the irrigation with CHX and CHX-ET. Moreover, CHX and CHX-ET showed the highest incidence of CSL (p .05), but without difference between them (p .05), regardless of the post-space third. DW and CHX-PA showed similar incidence of CSL (p .05). No difference on the incidence of open dentin tubules was found for any irrigation protocol and post-space third (p .05). The use of 1% PA prior the post-space irrigation with CHX decrease the incidence of CSL. RESEARCH HIGHLIGHTS: The post-space irrigation with chlorhexidine results in the formation of chemical smear layer. Ethanol is not capable to remove the chemical smear layer. Peracetic acid is more effective to remove the chemical smear layer.

We evaluated the effect of irrigation protocols in removing methylene blue after photodynamic therapy (PDT) in post-space dentin. Bond strength to dentin and failure mode after fiber post cementation was also evaluated. Ninety bovine teeth were endodontically treated. Post-space preparation and PDT mediated by 0.01% methylene blue and diode laser (660 nm) were performed. Three irrigations protocols were tested (n = 10): distilled water (DW), 2.5% sodium hypochlorite (SH), and 6% calcium hypochlorite (CH). Other specimens were used to investigate the bond strength to post-space dentin according to the irrigation protocol and the post cementation system used (RelyX U200 cement (RU) and GC Gold Label 1 glass ionomer cement (GC) in six groups (n = 10): DW-RU, SH-RU, CH-RU, DW-GC, SH-GC e CH-GC. Regardless of the post-space third, DW showed a lower incidence of residues than SH (p < 0.05), but similar to CH. SH showed similar results to CH (p > 0.05). Regarding the bond strength, CH-RU and CH-GC showed higher values compared to the other groups (p< 0.05), but similar to each other. No differences were observed between the other groups (p > 0.05). Cohesive was the most predominant failure. 6% CH to remove methylene blue after PDT favors the bond strength of RelyX U200 and GC Gold Label.

This study aimed to evaluate the bleaching efficacy, pH, and temperature of 35% hydrogen peroxide (HP) gel used alone or associated with violet LED.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 ∆EHP35VR 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).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.

Made available in DSpace on 2022-04-29T08:29:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-01 Background: Tooth whitening protocols with low concentration hydrogen peroxide (HP) appear to minimize the microstructural effect on teeth. In addition, light sources have been used to enhance bleaching efficiency. This study evaluated the color change and microhardness of a protocol with 6% HP photoactivated by LED/laser in comparison with 35% HP. Methods: Twenty bovine incisors were randomized in two groups: 6% HP + LED/laser and 35% HP (n=10). Teeth were submitted to staining using dark tea. Three whitening sessions were carried out according to the manufacturer's instructions. Enamel microhardness (VHN) and color change evaluation (∆L*, ∆a*, ∆b*, ∆E00 [CIEDE2000], and WID) before 24 hours and 7 days after the last whitening session were performed. Two-way repeated ANOVA and Bonferroni post-test was used (α = 0.05). Results: Both groups showed perceptible color changes, being more pronounce for 35% HP. Differences were observed for ∆a*, ∆b* and ∆E00 (p≤0.027), except for ∆L* (p>0.05). Differences were also found in the comparison among the evaluation times within the same group (p≤0.027), except for ∆a* results (p>0.05). WID showed that 35% HP exhibited high whiteness values. Regarding microhardness, the groups did not show significant differences (p>0.05). However, 35% HP showed decreased values after 7 days of the last whitening session compared to the baseline (p≤0.027). Conclusions: 6% HP + LED/laser promoted perceptible color change, but not comparable with 35% HP. No differences on enamel microhardness were observed between the whitening protocols. However, 35% HP showed decreased hardness after 7 days of whitening compared to baseline. Department of Restorative Dentistry School of Dentistry Araraquara São Paulo State University - UNESP Department of Restorative Dentistry School of Dentistry Araraquara São Paulo State University - UNESP

Made available in DSpace on 2022-04-29T08:32:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-09-01 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 (e0.05). 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. Department of Restorative Dentistry Endodontics and Dental Materials Bauru School of Dentistry University of São Paulo (USP) Department of Restorative Dentistry Araraquara School of Dentistry State University of São Paulo (UNESP) School of Dentistry Federal University of Pará (UFPA) Department of Restorative Dentistry Araraquara School of Dentistry State University of São Paulo (UNESP)

The objective of this in vitro study was to assess the effects of two antioxidants (sodium ascorbate [SA] and alpha-tocopherol [AT]) on the adhesive interface and dentin bond strength immediately after bleaching with 38 % hydrogen peroxide (38HP) in endodontically-treated teeth. Two stages of experimentation were carried out. Bovine incisors were allocated into four groups (n = 10/group for each experiment): NB, non-bleached restored crowns; 38HP, bleached and immediately restored crowns; 38HP-SA, bleached crowns and SA use; and 38HP-AT, bleached crowns and AT use. Hybrid layer length in dentin (μm) and bond strength (MPa) were assessed with confocal microscopy laser and micro-shear bond strength (μSBS) test, respectively. Failure mode was determined by stereomicroscope. Data analysis was performed with analysis of variance (ANOVA) and Kruskal-Wallis, Dunn, Tukey, and Fisher-exact tests (a = 0.05). Higher values of hybrid layer length were observed similarly in the NB and 38HP-SA groups. The highest μSBS mean values were observed in the NB group (18 .51 ? 1.33), whereas the SBS values for 38HP-AT (1.68 ? 0.32) were similar to the 38HP group (1.61 ? 0.51) (p > 0.05) and significantly lower than the 38HP-SA group (5.78 ? 0.71). Adhesive failures were predominant in the 38HP and 38HP-AT groups. Cohesive and mixed failures were mostly observed in the NB and 38HP-SA groups, respectively. In conclusion, AT has no immediate effect on the hybrid layer formation and μSBS of dentin. Although SA promotes an increase in hybrid layer formation, it was not reflected in the μSBS values.

Made available in DSpace on 2020-12-12T02:16:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-05-01 AIM: To evaluate the effect of two antioxidant formulations (sodium ascorbate and α-tocopherol) on fracture resistance of endodontically treated teeth. MATERIALS AND METHODS: Sixty human premolars were endodontically treated and divided into six groups (n = 10): G1 (negative control)-unbleached and restored with composite resin; G2 (positive control)-bleached in three sessions, using hydrogen peroxide (15 H2O2) plus titanium dioxide (TiO2) nanoparticles, photoactivated by LED laser system and restored with composite resin; G3-bleaching similar to G2, after the use of 10% sodium ascorbate gel for 24 hours and restored with composite resin; G4-similar to G3, but with the use of 10% sodium ascorbate solution and restored with composite resin; G5 and G6-similar to G3, but with the use of 10% α-tocopherol in alcohol or carbopol, respectively, and was also restored. A mechanical fracture resistance test was performed and the Kruskal-Wallis test was used to evaluate the results (α = 0.05). RESULTS: No statistical difference was observed in fracture resistance between groups (p > 0.05). Regarding the antioxidant and pharmaceutical formulation applied, no statistical difference was detected in any comparison (p > 0.05). The frequency of fractures considered favorable was higher in G1 and G3 compared to the other groups. CONCLUSION: The endodontically treated teeth bleached with 15 H2O2 plus TiO2 nanoparticles and photoactivated with the LED laser did not decrease the fracture resistance and the use of sodium ascorbate or α-tocopherol did not increase the crown fracture resistance. CLINICAL SIGNIFICANCE: The literature reports a significant reduction in the bond strength of restorations on the bleached dentin. Therefore, the use of antioxidant agents may have a promising effect on fracture resistance of endodontically treated teeth. Department of Restorative Dentistry Araraquara Dental School UNESP-Univ Estadual Paulista Department of Restorative Dentistry Araraquara Dental School UNESP-Univ Estadual Paulista