Abstract: The minimally invasive endodontic access is not directly associated with tooth discoloration in the presence of bioceramic or epoxy resin-based root canal sealers. This study aimed to evaluate the influence of minimally invasive access and endodontic sealer composition on the color stability of endodontically-treated teeth, the restorative material adaptation, and the presence of remaining filling material in the pulp chamber. Endodontic access surgery was performed in maxillary central incisors, either through conservative or minimally invasive approaches, and the root was filled with AH Plus or Bio-C Sealer. The crown color was measured with a spectrophotometer at baseline and after root obturation, restoration, and specimen storage for one year in an oven. The occurrence of voids in the restoration and the remaining filling material was analyzed using micro-CT scans. The Yellowness Index (YI) and color changes (∆E00) were calculated after each color measurement. Data of micro-CT were submitted to 2-way ANOVA, and YI and ∆E00 were analyzed with repeated-measures ANOVA. Pair-wise comparisons were performed with Tukey's test (α = 0.05). The experimental conditions had no effect on the presence of the remaining material. The minimally invasive access associated with Bio-C Sealer resulted in more voids between the restoration and the remaining filling material. Only the evaluation time affected YI and ∆E00 values. Specimens became more yellow after filling and storage in the oven (the highest ∆E00 values). The present study showed that sealer and minimally invasive cavities are not associated with crown color stability following endodontic treatment. Abstract resinbased resin based sealers endodonticallytreated endodontically treated teeth adaptation chamber incisors approaches BioC Bio C obturation microCT micro CT scans (YI E00 E (∆E00 measurement 2way way 2 ANOVA ∆E0 repeatedmeasures repeated measures Pairwise Pair wise Tukeys Tukey s α 0.05. 005 0.05 . 0 05 0.05) values values) treatment E0 (∆E0 ∆E 00 0.0 (∆E 0.

Resumo O objetivo deste estudo foi observar a satisfação dos pacientes com suas restaurações dentárias anteriores diretas e compará-las com a avaliação clínica do dentista usando os critérios FDI (Federation Dental International). Os pacientes pontuaram suas restaurações dentárias (n=106) anteriores em relação à satisfação (satisfatória / insatisfatória). Quando insatisfatória, ele foi entrevistado sobre a queixa. Na mesma sessão, as restaurações dentárias foram avaliadas clinicamente por dois dentistas utilizando os critérios FDI (escore 1-5) quanto aos aspectos estéticos, funcionais e biológicos. Estatística descritiva foi usada para frequências de escores atribuídos por pacientes e clínicos. Para comparar as frequências dos pacientes e dos clínicos, foi aplicado o teste Qui-quadrado (p ≤ 0,05). Os pacientes relataram suas restaurações como 52,8% satisfatórias e 47,8% insatisfatórias. Os clínicos reportaram as mesmas restaurações, 82,3% satisfatória e 17,6% insatisfatória. As queixas mais frequentes dos pacientes referiam-se à cor, seguida da forma anatômica, fratura e retenção do material e forma anatômica proximal. Comparando os índices de satisfação e insatisfação dos pacientes com os clínicos, não houve diferença em relação à estética. A frequência de restaurações insatisfatórias por dentistas foi significativamente menor quando as propriedades funcionais e biológicas foram comparadas com as opiniões dos pacientes. As restaurações foram mais frequentemente relatadas como satisfatórias pelos pacientes, sendo as principais queixas relacionadas a questões estéticas. Quando as avaliações dos clínicos e dos pacientes foram comparadas, observou-se que as frequências de restaurações satisfatórias por pacientes e clínicos foram semelhantes em relação às propriedades estéticas e significativamente diferentes em relação às propriedades funcionais e biológicas. comparálas compará las Federation International. International . International) n=106 n106 n 106 (n=106 insatisfatória insatisfatória) queixa sessão escore 15 1 5 1-5 estéticos biológicos Quiquadrado Qui quadrado p 0,05. 005 0,05 0 05 0,05) 528 52 8 52,8 478 47 47,8 823 82 3 82,3 176 17 6 17,6 referiamse referiam se cor proximal estética observouse observou n=10 n10 10 (n=10 1- 00 0,0 52, 4 47, 82, 17, n=1 n1 (n=1 0, n= (n= (n

Abstract The objective of this study was to observe patients’ satisfaction with their in-service direct anterior dental restorations and to compare it with clinical evaluation using FDI (Federation Dental International) criteria. Patients scored their own anterior dental restorations regarding satisfaction (satisfactory /dissatisfactory). If dissatisfaction was mentioned, then, they would be interviewed about the complaint. In the same session, the dental restorations were clinically evaluated by two dentists using FDI criteria (1-5 score) concerning esthetic, functional, and biological domains. Descriptive statistics were used for frequencies of scores attributed by patients and clinicians. In order to compare patients’ to clinicians’ frequencies, the Chi-square test was applied (p ≤ 0.05). A total of 106 restorations were evaluated by patients and clinicians. Patients reported 52.8% of restorations satisfactory and 47.8% dissatisfactory. Overall, clinicians reported the same restorations as 82,3% satisfactory and 17,6% dissatisfactory. Patients’ most frequent complaints referred to color, followed by anatomical form, fracture of material and retention, and approximal anatomical form. Comparing patients’ satisfaction and dissatisfaction rates to clinicians’ evaluation per criteria, there was no difference regarding esthetics. The frequency of dissatisfactory restorations by clinicians was significantly lower when functional and biological properties were compared with patients’ opinions. Direct anterior dental restorations were more frequently reported as satisfactory by patients and clinicians, being the main complaints related to esthetic issues. When clinicians and patients’ evaluations were compared, it was observed that the frequencies of satisfactory restoration by patients and clinicians were similar regarding esthetic properties, and significantly different regarding functional and biological properties. inservice in service Federation International /dissatisfactory. /dissatisfactory . /dissatisfactory) mentioned then complaint session 15 1 5 (1- score domains Chisquare Chi square p 0.05. 005 0.05 0 05 0.05) 10 528 52 8 52.8 478 47 47.8 Overall 823 82 3 82,3 176 17 6 17,6 color form retention esthetics opinions issues (1 00 0.0 52. 4 47. 82, 17, ( 0.

Aim To evaluate the influence of the biomodification of erosive lesions with a chitosan nanoformulation containing green tea (NanoCsQ) on the clinical performance of a composite resin. Methods The study was performed in a split-mouth, randomized and double-blinded model with 20 patients with 40 erosive lesions. The patient’s teeth were randomized into two groups (n=20) according to the surface treatment: 1) Without biomodification (control), and 2) Biomodification with NanoCsQ solution (experimental). The lesions were restored with adhesive (Tetric N-bond, Ivoclar) and composite resin (IPS Empress Direct, Ivoclar). The restorations were polished and 7 days (baseline), 6 months, and 12 months later were evaluated according to the United States Public Health Service (USPHS) modified criteria, using clinical exam and photographics. Data were analyzed by Friedman’s and Wilcoxon signed-rank tests. Results No significant differences were found between the control and experimental groups (p=0.423), and also among the follow-up periods (baseline, six months, and 12 months) (p=0.50). Regarding the retention criteria, 90% of the restoration had an alpha score in the control group. Only 10% of the restorations without biomodification (control) had a score charlie at the 12-month follow-up. None of the patients reported post-operatory sensitivity. Conclusion The NanoCsQ solution did not negatively affect the performance of the composite resin restorations after 12 months.

Abstract The survival of endodontically treated teeth depends on the remaining tooth structure. The aim of this study was to evaluate the impact of different access cavities on root canal preparation, restorative protocol, and fracture resistance of endodontically treated teeth. Fifty-six mandibular molars were divided into control (n=8) and experimental (n=16) groups according to access cavity: Traditional, Conservative, and Truss; and redistributed (n=8) according to instrumentation protocols: Reciproc Blue and R-motion. After, teeth were scanned in micro-CT and then filled and redistributed according to composite resin restoration (n=8): Filtek One BulkFill and Filtek Z350. A new micro-CT scan was performed to analyze the restorative material. Then, samples were submitted to fracture resistance testing and the failure pattern was determined. Data were analyzed using paired T-test, ANOVA, Tukey, and chi-square tests (α=0.05). In Truss, R-Motion promoted less transportation in different thirds of root canals. Higher percentages of voids (5.05%) and filling material (11.7%) were observed in Truss. Fracture resistance values were higher for the control group, followed by Truss, Conservative, and Traditional. The predominant failure pattern was type-II. In Truss, reciprocating instruments with smaller taper showed less canal transportation. Also, Truss provided higher values of fracture resistance, although it presented a higher percentage of voids and remaining filling material. Thus, in Truss, reciprocating files with smaller taper showed less canal transportation, and these cavities provided higher values of fracture resistance, although it presented a higher percentage of voids and remaining filling material. structure preparation protocol Fiftysix Fifty six n=8 n8 n 8 (n=8 n=16 n16 16 (n=16 cavity Traditional Conservative protocols Rmotion. Rmotion R motion. motion R-motion After microCT micro CT Z350 Z Then determined Ttest, Ttest T test, test T-test ANOVA Tukey chisquare chi square α=0.05. α005 α α=0.05 . 0 05 (α=0.05) RMotion Motion canals 5.05% 505 5 (5.05% 11.7% 117 11 7 (11.7% group typeII. typeII type II. II type-II Also Thus n= (n= n=1 n1 1 (n=1 Z35 α00 α=0.0 (α=0.05 5.05 50 (5.05 11.7 (11.7 (n Z3 α0 α=0. (α=0.0 5.0 (5.0 11. (11. α=0 (α=0. 5. (5. (11 α= (α=0 (5 (1 (α= ( (α

Abstract This study aimed to analyze the root and root canal morphology of mandibular first and second molars using CBCT images. A total of 2,400 mandibular molars exams were selected from 600 patients aged between 18 and 75 years. The number of roots, number of root canals, and root canal configuration according to the Vertucci classification were verified. Overall, 94.92% of mandibular first molars and 90.17% of mandibular second molars had two separate roots. Among the biradicular molars, the first molars showed a greater incidence of type IV canals in the mesial root and type I in the distal root. In the second molars, the most common canal form was type IV in the mesial root and type I in the distal root. In the triradicular molars, the type IV and type I configurations were the most common in the mesial root of the first molar and second molar, respectively. In both triradicular molars, there was a prevalence of type I canal in the distal and DL roots. Statistical analysis was performed at a significance level of 0.05. The number of roots was correlated with gender (Spearman test), and the canal's configuration with gender and bilaterality (Wilcoxon test). The subpopulation studied has a high incidence of bilateral symmetry and mandibular molars with two roots with two distinct mesial canals and one distal canal. The bilateral configuration is possible to estimate the number of canals, especially in images that are difficult to visualize, such as atresic canals.

Abstract Degradation of the dentin-resin interface can occur due to hydrolysis of exposed collagen, resulting in reduced bond strength. This study assessed the effect of dentin treatment with chitosan combined with an etch-and-rinse or self-etch adhesive system on improvement of bond strength and preservation of the interface durability. Methodology Enamel was removed from 80 molars and the teeth were divided into two groups: without chitosan (control) or with 2.5% chitosan gel (1 min). They were further subdivided into two subgroups according to the adhesive system: etch-and-rinse or self-etch. Dentin was restored using a composite resin. Half of the specimens from each restored group were subjected to interface aging and the remaining specimens were used for immediate analysis. The specimens were sectioned and subjected to microtensile bond strength (µTBS) test (n=10), chemical composition testing using Fourier-transform infrared (FTIR) spectroscopy (n=4) and energy-dispersive spectroscopy (EDS) (n=5), and morphological analysis of the adhesive interface using scanning electron microscopy (SEM) (n=5). Data were analyzed using three-way ANOVA. Results Chitosan improved the µTBS of the adhesive interface when compared with the control group (p=0.004). No significant differences were observed in dentin adhesion between the adhesive systems (p=0.652). Immediate µTBS was not significantly different from that after 6 months (p=0.274). EDS and SEM did not show significant differences in the chemical and structural composition of the specimens. FTIR showed a decrease in the intensity of phosphate and carbonate bands after using chitosan. Conclusions Dentin treatment with chitosan combined with an etch-and-rinse or self-etch adhesive system improved the immediate and preserved the 6-month bond strength of the adhesive interface.

Resumo Propõe-se estimar a prevalência da autopercepção da necessidade de prótese dentária total entre idosos (65 a 74 anos) brasileiros desdentados, assim como identificar seus fatores associados. Trata-se de estudo transversal com base no inquérito nacional das condições de Saúde Bucal da população brasileira, denominado SB Brasil – 2010. A variável dependente foi a autopercepção da necessidade de prótese dentária total, considerando a aquisição de prótese nova ou substituição da existente. Foram conduzidas análises descritivas, bivariadas e múltiplas. Foram incluídos 3514 idosos, destes, 2039 (55,0%) perceberam a necessidade de prótese total. A autopercepção da necessidade de prótese total foi maior entre os que necessitavam de prótese dentária inferior e que estavam insatisfeitos com as suas condições de saúde bucal. Além da alta prevalência da autopercepção da necessidade de prótese identificada, os resultados permitiram identificar que condições normativas e subjetivas de saúde bucal se mantiveram associadas a esta autopercepção entre idosos brasileiros.

Abstract The objective is to estimate the prevalence of self-perception of the need for a full dental prosthesis among toothless elderly Brazilians aged 65 to 74, as well as identify the associated factors. It is a cross-sectional study based on the national survey of oral health conditions of the Brazilian population, called SB Brazil – 2010. The dependent variable was the self-perceived need for full dental prosthesis, considering the purchase of new or replacement of the existing prosthesis. Descriptive bivariate and multiple analyses were conducted on 3514 elderly people, of which 2039 (55%) elderly self-perceived the need for a full denture. The self-perception of the need for a full denture was higher among those who needed dental prosthesis and who were dissatisfied with their oral health conditions. In addition to the high prevalence of self-perception of the need for prosthesis identified, the results identified that normative and subjective conditions of oral health remained associated with this self-perception among elderly Brazilians.

Resumo Propõe-se estimar a prevalência da autopercepção da necessidade de prótese dentária total entre idosos (65 a 74 anos) brasileiros desdentados, assim como identificar seus fatores associados. Trata-se de estudo transversal com base no inquérito nacional das condições de Saúde Bucal da população brasileira, denominado SB Brasil – 2010. A variável dependente foi a autopercepção da necessidade de prótese dentária total, considerando a aquisição de prótese nova ou substituição da existente. Foram conduzidas análises descritivas, bivariadas e múltiplas. Foram incluídos 3514 idosos, destes, 2039 (55,0%) perceberam a necessidade de prótese total. A autopercepção da necessidade de prótese total foi maior entre os que necessitavam de prótese dentária inferior e que estavam insatisfeitos com as suas condições de saúde bucal. Além da alta prevalência da autopercepção da necessidade de prótese identificada, os resultados permitiram identificar que condições normativas e subjetivas de saúde bucal se mantiveram associadas a esta autopercepção entre idosos brasileiros.

Abstract The objective is to estimate the prevalence of self-perception of the need for a full dental prosthesis among toothless elderly Brazilians aged 65 to 74, as well as identify the associated factors. It is a cross-sectional study based on the national survey of oral health conditions of the Brazilian population, called SB Brazil – 2010. The dependent variable was the self-perceived need for full dental prosthesis, considering the purchase of new or replacement of the existing prosthesis. Descriptive bivariate and multiple analyses were conducted on 3514 elderly people, of which 2039 (55%) elderly self-perceived the need for a full denture. The self-perception of the need for a full denture was higher among those who needed dental prosthesis and who were dissatisfied with their oral health conditions. In addition to the high prevalence of self-perception of the need for prosthesis identified, the results identified that normative and subjective conditions of oral health remained associated with this self-perception among elderly Brazilians.

Abstract The volume of sealer in the apical 1 mm of teeth filled using different techniques was evaluated by micro-commuted tomography (micro-CT). Sixty-four maxillary central incisors were prepared using NiTi rotary instruments. Teeth were randomly distributed into four groups according to root canal sealers (AH Plus, Endofill, Sealapex, and Sealer 26) and subdivided into two subgroups according to the filling techniques (active and passive lateral condensation; n = 8 each). Subsequently, teeth were examined using the 1174 SkyScan micro-CT device. Images were reconstructed using the NRecon software, and the sealer volume (mm3) in the apical region was analyzed using the two-way ANOVA and post-hoc Student–Newman–Keuls test (α = ٠.٠٥). The lowest volume of sealer was observed in teeth filled with Sealapex (0.100 ± 0.009) and Endofill (0.103 ± 0.010). The highest volume was observed in teeth filled with AH Plus (0.112 ± 0.008) and Sealer 26 (0.109 ± 0.018) (p > 0.05). Regarding the filling technique, a lower sealer volume was observed using the active lateral condensation technique compared with that using the passive lateral condensation technique (0.100 ± 0.010 vs. 0.111 ± 0.012) (p < 0.05). Therefore, the lowest volume of sealer was observed in teeth filled with Sealapex and Endofill using the active lateral condensation technique.

This study evaluates the effect of two thermoplastic obturation systems (MicroSeal and Obtura II) on bond strength of different sealers to intraradicular dentin. Sixty root canals of human canines were prepared using ProTaper rotary files (crown-down technique) and irrigated with 2.5% sodium hypochlorite and 17% EDTA. The root canals were filled by MicroSeal, Obtura II, or lateral compaction techniques using AH Plus and Epiphany SE. 1.5 mm thick root slices were subjected to the push-out test. ANOVA and Tukey's test showed that the bond strength values (MPa) observed in the groups obturated with MicroSeal (2.96 ± 2.72) and Obtura II (2.68 ± 2.18) did not significantly differ from each other (p > 0.05) but were significantly higher than that observed in the group obturated with lateral condensation (2.01 ± 1.48; p < 0.05). There were no statistically significant differences in strength (p > 0.05) among the root canal thirds (cervical: 2.44 ± 2.03; middle: 2.50 ± 2.27; and apical: 2.70 ± 2.34). Adhesive failures were predominant (60%) in all groups. In conclusion, MicroSeal and Obtura II techniques, using AH plus sealer, increased the resistance to displacement of the filling material, when compared with lateral compaction. Moreover, when used with Epiphany SE, these obturation systems did not affect the bond strength of the material to root dentin.

Este estudo utilizou microtomografia computadorizada (micro-CT) para avaliar a adaptação do cone de guta-percha no momento da sua seleção, o volume de guta-percha no material obturador, e o volume do material obturador em relação ao canal no limite apical do comprimento de trabalho. Canais radiculares de 20 incisivos centrais superiores foram preparados com instrumentos rotatórios e distribuídos em dois grupos (n=10). A ponta do cone de guta-percha foi plastificada (técnica de impressão térmica apical - TIT) ou não (técnica convencional - TC), e seu ajuste apical foi verificado. O milimetro apical do comprimento de trabalho foi examinado em micro-CT, os canais foram preenchidos com guta-percha e cimento, e novas imagens em micro-CT foram obtidas. Na TC, a guta-percha preencheu 35,83 ± 15,05% do canal no momento da seleção do cone e 38,72 ± 11,64% após a obturação. Na TIT, estes valores foram de 23,14 ± 7,74% e 26,98 ± 20,40%, respectivamente. O volume de guta-percha no material obturador, e o volume do material obturador em relação ao canal, foram, respectivamente, 61,28 ± 11,64% e 87,76 ± 9,98% para a TC, e 73,00 ± 20,41% e 89,96 ± 9,08% para TIT. Não foi encontrada diferença significativa entre a seleção do cone e depois o preenchimento do canal para ambas as técnicas, TC (p =0,593) ou TIT (p=0,4975). As técnicas não diferiram significativamente com respeito ao volume de guta-percha no material obturador (p=0,132), e volume de preenchimento de material em relação ao canal (p=0,612). Um ajuste ideal do cone principal de guta-percha cone no seu comprimento de trabalho não foi alcançado, independentemente da técnica de seleção empregada, e a area preenchida pelo material obturador foi semelhante para ambas as técnicas.

This study used micro-computed tomography (micro-CT) to evaluate the fit of the master gutta-percha cone at time of cone fit, gutta-percha volume in the filling material, and the filling material volume in relation to the canal at the apical limit of the working length. Root canals of 20 maxillary central incisors were prepared with rotary instruments and distributed into two groups (n=10). The gutta-percha cone tip was either plasticized (apical thermal impression technique - ATI) or not (conventional technique - CT), and its apical fit was checked. The apical 1 mm of working length was examined with a micro-CT, canals were filled with gutta-percha and sealer, and new micro-CT scans were obtained. In CT, gutta-percha filled 35.83 ± 15.05% of the canal at cone selection and 38.72 ± 11.64% after filling. In ATI, these values were 23.14 ± 7.74% and 26.98 ± 20.40%, respectively. Gutta-percha volume in the filling material, and filling material volume in relation to the canal were, respectively, 61.28 ± 11.64% and 87.76 ± 9.98% for CT, and 73.00 ± 20.41% and 89.96 ± 9.08% for ATI. No significant difference was found between cone selection and after canal filling, for either CT (p=0.593) or ATI (p=0.4975). The techniques did not differ significantly with respect to gutta-percha volume in the filling material (p=0.132) and filling material volume in relation to the canal (p=0.612). An ideal fit of the master gutta-percha cone at working length was not achieved regardless of the cone selection technique, and the material-filled area was similar for both techniques.

O objetivo deste estudo foi avaliar a influência do pré-tratamento de superfície dos pinos de fibra de vidro na resistência à flexão (RF), módulo de elasticidade (ME) e morfologia, bem como a resistência de união (RU) entre os pinos e o núcleo de preenchimento. Cinqüenta e dois pinos de fibra de vidro (lisos e serrilhados) foram divididos em 4 grupos (n=13): sem tratamento (controle), peróxido de hidrogênio a 10% por 10 min (HP-10), peróxido de hidrogênio 24% por 1 min (HP-24) e jato de óxido de alumínio (Al2O3). Para avaliar a RF e ME, o ensaio de flexão de 3 pontos foi realizado. Três pinos de cada grupo foram examinados em MEV. Resina composta foi utilizada como núcleo de preenchimento e as amostras foram seccionadas para obter palitos de microtração. Os dados foram analisados por ANOVA e teste de Tukey (α=0,05). Na RF, observou-se diferença estatisticamente significante entre os pinos e tipo de pré-tratamento de superfície (p<0,05), com as maiores médias para os pinos lisos. Al2O3 proporcionou maior RF que HP-24. Al2O3 promoveu maior ME que HP-24 e grupo controle. MEV revelou dissolução parcial da matriz de resina em todos os grupos tratados. Os pinos lisos tiveram a maior RU (p<0,05). Os pinos lisos apresentaram RF e RU superior aos pinos serrilhados (p<0,05). As propriedades mecânicas dos pinos de fibra de vidro e a resistência de união entre os pinos e o material resinoso não foram alterados pelos tratamentos de superfície, com exceção do jato de óxido de alumínio que aumentou o módulo de elasticidade dos pinos.

The aim of this study was to assess the influence of surface pretreatments of fiber-reinforced posts on flexural strength (FS), modulus of elasticity (ME) and morphology of these posts, as well as the bond strength (BS) between posts and core material. Fifty-two fiber posts (smooth and serrated) were assigned to 4 groups (n=13): no treatment (control), 10% hydrogen peroxide (HP) for 10 min (HP-10), 24% HP for 1 min (HP-24) and airborne-particle abrasion (Al2O3). To evaluate FS and ME, a 3-point bending test was performed. Three posts of each group were examined by scanning electron microscopy. Composite resin was used as the core build-up and samples were sectioned to obtain microtensile sticks. Data were analyzed by ANOVA and Tukey's test (α=0.05). For FS, significant differences were observed between posts type and surface pretreatment (p<0.05), with the highest means for the smooth posts. Al2O3 provided higher FS than HP-24. Al2O3 promoted higher ME than HP-24 and control. SEM images revealed partial dissolution of the resin matrix in all treated groups. The smooth posts had higher BS and FS than serrated posts (p<0.05). Mechanical properties of the glass fiber posts and the bond strength between posts and composite material were not altered by the surface treatments, except for airborne-particle abrasion that increased the post elastic modulus.

Este estudo avaliou o efeito de agentes clareadores na resistência de união da interface dentina/resina e resistência à flexão da dentina. Quarenta caninos superiores foram selecionados para o estudo. No teste de cisalhamento, 40 fragmentos de dentina intracoronária (5 x 5 mm) obtidos a partir de superfícies vestibulares das coroas foram incluídos em resina acrílica. No teste de flexão, 40 barras de dentina (8 x 2 x 2 mm) foram obtidas a partir das raízes. As 40 hemi-seções da superfície lingual foram preparadas para microscopia eletrônica de varredura (MEV). Os espécimes foram divididos em 4 grupos de acordo com o protocolo de clareamento (n=10): Não clareados (controle), perborato de sódio + peróxido de hidrogênio 20% (PS + PH 20%), peróxido de carbamida 37% (PC37%) e peróxido de hidrogênio 38% (PH 38%). Após 7 dias, as amostras destinadas à resistência de união foram restauradas e submetidas ao teste. As barras de dentina foram clareadas e submetidas ao teste de flexão de 3 pontos. Os dados (MPa) foram analisados por ANOVA e teste de Tukey (α=0,05). No teste de cisalhamento, o controle foi superior (p<0,05) aos grupos clareados, que foram semelhantes entre si (p>0,05). Na resistência à flexão, o grupo controle também exibiu os maiores valores, diferente dos demais (p<0,05). SEM revelou camada de smear em todos os grupos, com fissuras nos espécimes clareados. PS + 20% PH e PH 38% apresentaram interfaces de descontínuas com poucos tags. A resistência de união do material restaurador à dentina e a resistência à flexão da dentina foram reduzidas após o uso de agentes clareadores de alta concentração

This study evaluated the effect of bleaching agents on bond strength at the dentin/resin interface and the flexural strength of dentin. Forty maxillary canines were selected for the study. In the shear strength test, 40 slabs of intracoronary dentin (5 x 5 mm) obtained from buccal surfaces of the crowns were included in acrylic resin. In the flexural strength test, 40 dentin bars (8 x 2 x 2 mm) were obtained from the roots. The 40 hemi-sections of the lingual surface were prepared for scanning electron microscopy (SEM). The specimens were divided into 4 groups according to the bleaching protocol (n=10): Unbleached (control), Sodium perborate + 20% hydrogen peroxide (SP + 20% HP), 37% carbamide peroxide (37% CP) and 38% hydrogen peroxide (38% HP). After 7 days, the bond strength specimens were restored and tested. Dentin bars were bleached and subjected to a three-point bending test. Data (MPa) were analyzed by ANOVA and Tukey's test (α=0.05). In the shear test, the control group was superior (p<0.05) to the bleached groups, which, in turn, were statistically similar (p>0.05). In the flexural strength test, the control group also had the highest values and differed significantly from the other groups (p<0.05). SEM revealed smear layer in all groups, with fissures in the bleached specimens. SP + 20% HP and 38% HP showed discontinuous interfaces with few tags. In conclusion, bond strength of restorative material to dentin and flexural strength of dentin were reduced after the use of high-concentration bleaching agents.

Este estudo avaliou a influência de protocolos de clareamento na temperatura intrapulpar e resistência à fratura de dentes clareados. Noventa incisivos superiores foram divididos em 9 grupos (n=10): G1: peróxido de carbamida a 35% (PC 35%), G2: peróxido de hidrogênio a 38% (PH 38%), G3: luz halógena, G4: LED-laser, G5: PC 35% + luz halógena, G6: PH 38% + luz halógena, G7: PC 35% + LED-laser, G8: PH 38% + LED-laser e G9: sem tratamento (controle). O canal radicular foi alargado, um termopar foi introduzido no ápice até a câmara pulpar e a temperatura foi calculada (°C). A resistência à fratura (kN) foi determinada em máquina Instron. Os dados foram analisados por análise de variância e teste de Tukey (p>0,05). A luz halógena utilizada isoladamente (1,10 ± 0,24) (G3) e associada ao PH 38% (1,15 ± 0,30) (G6) proporcionaram os maiores valores de temperatura, sendo estatisticamente diferentes dos demais grupos (p<0,05). O G1 (0,15 ± 0,06) e o G6 (0,19 ± 0,07) produziram os menores valores de resistência à fratura, sendo estatisticamente diferentes (p<0,05) do G5 (0,65 ± 0,49). Os protocolos de clareamento aumentaram a temperatura, mas nenhum incremento excedeu o valor crítico de 5,6oC. O PC 35%, PH 38% e as fontes de luz utilizadas isoladamente não alteraram a resistência à fratura dos dentes.

This study evaluated the influence of bleaching protocols on intrapulpal temperature and fracture strength of the bleached teeth. Ninety maxillary incisors were assigned to 9 groups (n=10): G1: 35% carbamide peroxide (35% CP), G2: 38% hydrogen peroxide (38% HP), G3: halogen light, G4: LED-laser, G5: 35% CP + halogen light, G6: 38% HP + halogen light, G7: 35% CP + LED-laser, G8: 38% HP + LED-laser, and G9: no treatment (control). Pulp space was widened, a thermocouple was introduced through the apex up to the pulp chamber and the temperature was recorded (°C). The fracture strength (kN) was determined using an Instron machine. Data were analyzed by ANOVA and Tukey's test (p<0.05). The halogen light alone (1.10 ± 0.24) (G3) and associated with 38% HP (1.15 ± 0.30) (G6) produced the highest temperature increase, statistically different (p<0.05) from the other groups. G1 (0.15 ± 0.06) and G6 (0.19 ± 0.07) produced the lowest values, statistically different (p<0.05) from G5 (0.65 ± 0.49). The bleaching protocols increased the temperature, but no increment exceeded the critical value of 5.6°C. Neither 35% CP nor 38% HP or the light sources alone altered the fracture strength of the teeth.

Este estudo avaliou o efeito de protocolos de clareamento com peróxido de hidrogênio 38% (PH) e tempos pós-clareamento na resistência ao cisalhamento de uma resina composta á dentina. Cem fragmentos de dentina intracoronária foram incluídos e distribuídos aleatoriamente em 2 grupos experimentais de acordo com o protocolo de clareamento: PH (2 aplicações de 10 min cada) e HP ativado por LED laser (2 aplicações de 10 min cada/45 s de ativação pela luz). Os grupos foram subdivididos de acordo com o tempo pós-clareamento (n=10): 1 dia, 3 dias, 7 dias, 10 dias e 14 dias. O grupo controle não foi clareado e apenas restaurado (n=10). Os espécimes foram restaurados com sistema adesivo Single Bond/resina Filtek Z250 usando matriz de teflon. Após 24 h, foram submetidos ao teste de cisalhamento. Os dados foram analisados por ANOVA e teste de Tukey (α=0,05). O grupo não clareado (0,283 ± 0,134) apresentou a maior resistência de união e foi estatisticamente semelhante (p>0,05) ao PH- 10 dias (0,278 ± 0,064), PH + LED laser/10 dias (0,280 ± 0,078), PH/14 dias (0,281 ± 0,104), PH + LED laser/14 dias (0,277 ± 0,093). Resistência de união inferior foram verificadas para PH/1 dia (0,082 ± 0,012), PH/3 dias (0,079 ± 0,013), PH + LED laser/1 dia (0,073 ± 0,018) e PH + LED laser/3 dias (0,080 ± 0,015), que foram estatisticamente semelhantes entre si (p>0,05). HP/7 dias (0,184 ± 0,154) e PH + LED laser/7 dias (0,169 ± 0,102) apresentaram valores intermediários (p<0,05). O procedimento restaurador da dentina intracoronária clareada com peróxido de hidrogênio 38%, com ou sem o uso de fonte de luz, deve ser realizado pelo menos após 10 dias do tratamento clareador.

This study assessed the effect of bleaching protocols with 38% hydrogen peroxide (HP) and post-bleaching times on shear bond strength of a composite resin to dentin. One-hundred slabs of intracoronary dentin were included and randomly assigned into 2 groups according to the bleaching protocol: HP (2 applications of 10 min each) and HP activated by LED laser (2 applications of 10 min each/45 s of light activation). Groups were subdivided according to the post-bleaching time (n=10): 1 day, 3 days, 7 days, 10 days and 14 days. The control group was unbleached and restored (n=10). The specimens were restored with Single Bond adhesive system/Filtek Z250 resin using a polytetrafluorethylene matrix and were submitted to the shear bond strength testa after 24 h,. Data were analyzed by ANOVA and Tukey's test (α=0.05). Unbleached group (0.283 ± 0.134) had the highest bond strength and was statistically similar (p>0.05) to HP/10 days (0.278 ± 0.064), HP + LED laser/10 days (0.280 ± 0.078), HP/14 days (0.281 ± 0.104), HP + LED laser/14 days (0.277 ± 0.093). Lower bond strength were verified in HP/1 day (0.082 ± 0.012), HP/3 days (0.079 ± 0.013), HP + LED laser/1 day (0.073 ± 0.018) and HP + LED laser/3 days (0.080 ± 0.015), which were statistically similar (p>0.05). HP/7 days (0.184 ± 0.154) and HP + LED laser/7 days (0.169 ± 0.102) had intermediate values (p<0.05). The restorative procedure of intracoronary dentin bleached with 38% HP with or without the use of light source should be performed after at least 10 days after the bleaching treatment.