Normative and subjective need for dental prosthesis: accuracy and agreement in a population based-study.

The aim of our study was to compare normative need for dental prosthesis (estimated by dentists) with subjective need (self-reported) by testing the accuracy and agreement and comparing direction and magnitude of associations with independent variables using both as outcomes. A representative sample of a birth cohort study (n = 900) was assessed at 31 years of age. Subjective need was obtained from questionnaire. Both normative and subjective need variables were dichotomized in (a) individuals with need for dental prosthesis and (b) without need for dental prosthesis. Accuracy was assessed by sensitivity (SE), specificity (SP), positive (PPV) and negative (NPV) predictive values. Agreement of normative and subjective need was assessed estimating kappa index. Sex, income, educational level, use of dental services and self-reported oral health were used to compare the associations with normative and subjective need. Prevalence of normative need was 48.9% and subjective need was 34.9%. Agreement (kappa: 0.43) and accuracy between normative and subjective need for dental prosthesis was low (SE: 56.5, 95%CI: 50.3-62.6; SP: 85.8, 95%CI: 81.1-89.7; PPV: 79.1, 95%CI: 72.6-84.7; NPV: 67.3, 95%CI: 62.1-72.2). When considering individuals with loss in anterior teeth, results showed a good agreement (kappa: 0.82) and accuracy between normative and subjective need (SE: 93.3, 95%CI: 68.1-99.8; SP: 88.9, 95%CI: 51.8-99.7; PPV: 93.3, 95%CI: 68.1-99.8; NPV: 88.9, 95%CI: 51.8-99.7). Direction and magnitude of associations with normative and subjective need were similar. Thus, normative need for dental prosthesis differs from subjective need in adults, except when anterior losses are present.

Determinants of dental prosthetic treatment need: A birth cohort study.

OBJECTIVES: To estimate the incidence of the need for a dental prosthesis during early adulthood and its association with socioeconomic and oral disorder trajectories. METHODS: In 1982, in the city of Pelotas, all live births (n = 5914) and their mothers were assessed. A representative sample of this cohort study was examined for oral health conditions at 15, 24 and 31 years (Oral Health Study-OHS). The need for a dental prosthesis was assessed at 24 and 31 years of age, and variables of interest (gender, skin colour, socioeconomic status (SES), use of dental services, caries and periodontal disease) were collected from different waves of this cohort. Longitudinal association between outcome and variables of interest was assessed using multilevel mixed models. RESULTS: A total of 539 individuals were assessed in 2013 (60.7% response rate). The need for a dental prosthesis was 28.9% at 24 years. (95% CI 24.9-33.2) and 49.0% at 31 years (95% CI 44.7-53.3). Risk of presenting with a need for a dental prosthesis was higher in users of public services. Downwardly mobile and lower SES trajectory groups presented a higher risk of the need for a dental prosthesis. High-risk caries trajectory group showed a higher risk of presenting with the need for a dental prosthesis from 24 to 31 years. CONCLUSIONS: Our findings demonstrate that the need for dental prosthesis from 24 to 31 years old was determined by trajectories of exposure during the life cycle, reinforcing that tackling socioeconomic inequalities at any stage of life can have an effect on an individual's oral health.

Normative and subjective need for dental prosthesis: accuracy and agreement in a population based-study / Necessidade normativa e subjetiva de próteses dentárias: acurácia e concordância em um estudo populacional / Necesidad normativa y subjetiva de prótesis dentales: precisión y concordancia en un estudio poblacional

Abstract: The aim of our study was to compare normative need for dental prosthesis (estimated by dentists) with subjective need (self-reported) by testing the accuracy and agreement and comparing direction and magnitude of associations with independent variables using both as outcomes. A representative sample of a birth cohort study (n = 900) was assessed at 31 years of age. Subjective need was obtained from questionnaire. Both normative and subjective need variables were dichotomized in (a) individuals with need for dental prosthesis and (b) without need for dental prosthesis. Accuracy was assessed by sensitivity (SE), specificity (SP), positive (PPV) and negative (NPV) predictive values. Agreement of normative and subjective need was assessed estimating kappa index. Sex, income, educational level, use of dental services and self-reported oral health were used to compare the associations with normative and subjective need. Prevalence of normative need was 48.9% and subjective need was 34.9%. Agreement (kappa: 0.43) and accuracy between normative and subjective need for dental prosthesis was low (SE: 56.5, 95%CI: 50.3-62.6; SP: 85.8, 95%CI: 81.1-89.7; PPV: 79.1, 95%CI: 72.6-84.7; NPV: 67.3, 95%CI: 62.1-72.2). When considering individuals with loss in anterior teeth, results showed a good agreement (kappa: 0.82) and accuracy between normative and subjective need (SE: 93.3, 95%CI: 68.1-99.8; SP: 88.9, 95%CI: 51.8-99.7; PPV: 93.3, 95%CI: 68.1-99.8; NPV: 88.9, 95%CI: 51.8-99.7). Direction and magnitude of associations with normative and subjective need were similar. Thus, normative need for dental prosthesis differs from subjective need in adults, except when anterior losses are present.

Resumo: O estudo teve como objetivo comparar a necessidade normativa de prótese dentária (estimada por dentista) com a necessidade subjetiva (autorrelatada), testando a acurácia e concordância e comparando a direção e magnitude das associações com variáveis independentes, usando necessidade normativa e subjetiva como os desfechos. Foi avaliada uma amostra representativa de uma coorte de nascimentos (n = 900), aos 31 anos de idade. A necessidade subjetiva foi obtida com um questionário. As variáveis necessidade normativa e subjetiva foram analisadas dicotomicamente como: (a) com necessidade de prótese dentária e (b) sem necessidade de prótese dentária. A acurácia foi avaliada enquanto sensibilidade (SE), especificidade (SP), valor preditivo positivo (VPP) e valor preditivo negativo (VPN). A concordância entre necessidade normativa e subjetiva foi avaliada com a estimativa do índice kappa. Sexo, renda, escolaridade, uso de serviços de odontologia e percepção da própria saúde oral foram usados para comparar as associações entre necessidade normativa e subjetiva. A prevalência de necessidade normativa era 48,9% e de necessidade subjetiva, 34,9%. A concordância (kappa: 0,43) e acurácia entre as necessidades normativa e subjetiva de prótese dentária eram baixas (SE: 56,5, IC95%: 50,3-62,6; SP: 85,8, IC95%: 81,1-89,7; VPP: 79,1, IC95%: 72,6-84,7; VPN: 67,3, IC95%: 62,1-72,2). Nos indivíduos com perda de dentes anteriores, os resultados mostraram boa concordância (kappa: 0,82) e acurácia entre necessidade normativa e subjetiva (SE: 93,3, IC95%: 68,1-99,8; SP: 88,9, IC95%: 51,8-99,7; VPP: 93,3, IC95%: 68,1-99,8; VPN: 88,9, IC95%: 51,8-99,7). A direção e magnitude das associações com necessidade normativa e subjetiva eram semelhantes. Portanto, a necessidade normativa de prótese dentária difere da necessidade subjetiva em adultos, exceto quando há perda de dentes anteriores.

Resumen: El objetivo de este estudio fue comparar la necesidad normativa de prótesis detal -estimada por los dentistas- con la necesidad subjetiva -autoinformada-, probando la precisión y concordancia, así como comparando la dirección y magnitud de asociaciones con variables independientes, usando ambas como resultados. Se evaluó una muestra representativa de un estudio de cohorte de nacimientos (n = 900) a los 31 años de edad. La necesidad subjetiva procede de un cuestionario. Ambas variables necesidad normativa y subjetiva fueron dicotomizadas en (a) individuos con necesidad de una prótesis dental y (b) sin necesidad de una prótesis dental. La precisión se evaluó por sensibilidad (SE), especificidad (SP), valores predictivos positivos (PPV) y negativos (NPV). La concordancia entre necesidad normativa y subjetiva se evaluó estimando el índice de kappa. Sexo, ingresos, nivel educacional, uso de servicios dentales y autoinformados de salud oral se usaron para comparar las asociaciones con necesidad normativa y subjetiva. La prevalencia de necesidad normativa fue 48,9% y la de necesidad subjetiva fue 34,9%. Concordancia (kappa: 0,43) y precisión entre la necesidad normativa y subjetiva de prótesis dental fue baja (SE: 56,5, IC95%: 50,3-62,6; SP: 85,8, IC95%: 81,1-89,7; PPV: 79,1, IC95%: 72,6-84,7; NPV: 67,3, IC95%: 62,1- 72,2). Cuando consideramos a individuos con pérdidas de dientes anteriores, los resultados mostraron una buena concordancia (kappa: 0,82) y precisión entre necesidad normativa y subjetiva (SE: 93,3, IC95%: 68,1-99,8; SP: 88,9, IC95%: 51,8-99,7; PPV: 93,3, IC95%: 68,1-99,8); NPV: 88,9, IC95%: 51,8-99,7). La dirección y magnitud de las asociaciones con necesidad normativa y subjetiva fueron similares. Por lo tanto, la necesidad normativa de prótesis dentales difiere de la necesidad subjetiva en adultos, excepto cuando están presentes las pérdidas de dientes anteriores.

Effect of temperature and storage time on dental bleaching effectiveness.

OBJECTIVE: To evaluate the effect of storage time and temperature on the effectiveness of bleaching agents. METHODS: Enamel slabs were randomly allocated according to the concentration of carbamide peroxide (CP): 10% (CP10) and 16% (CP16). Shade evaluations were conducted at baseline and then after 3 and 12 months of storage at 3 different temperatures: 10°C (±2°C), 25°C (±2°C), and 35°C (±2°C). Objective color evaluation was performed (spectrophotometer CIEL*a*b* system and CIEDE2000) to calculate the color change (ΔE00 ). Subjective evaluation was performed using the VITA classical shade guide followed by shade variation (ΔS). RESULTS: The bleaching effect of different CP concentrations (10% and 16%) at baseline showed no differences with regard to objective (ΔE00 ) and subjective parameters (ΔS) (P > .05). No differences were observed between CP concentrations stored for the same length of time and at the same temperature for either parameter (P > .05). In terms of objective measurement (ΔE00 ), a reduction in the bleaching effect was shown for both CP concentrations (10% and 16%) when stored for 12 months at 35°C, and compared with the baseline (P < .05). As regards the subjective parameters (ΔS), after 12 months, both CP concentrations (10% and 16%) stored at 35°C showed a decrease in bleaching capacity compared to baseline (P < .05). CP10 and CP16 stored at 10°C and 25°C did not suffer any loss in bleaching ability, even after 12 months (P > .05). CONCLUSIONS: The storage of bleaching agents for long periods at high temperatures can reduce the bleaching effectiveness of CP at 10% and 16%. CLINICAL SIGNIFICANCE: Clinicians must be made aware that they should store their bleaching products under proper temperature conditions and use them within an appropriate time frame; otherwise, the bleaching effect could be lost.

Surface roughness and bond strength between Y-TZP and self-adhesive resin cement after air particle abrasion protocols.

The aim of this study was to evaluate the influence of different air particle abrasion (APA) protocols-with variations in particle types, duration of application, and the distance between the device tip and the ceramic-on the surface roughness (SR) of zirconia-based ceramic (yttria-stabilized tetragonal zirconia polycrystal [Y-TZP]) and the shear bond strength (SBS) between Y-TZP and resin cement. In total, 135 sintered Y-TZP blocks were polished and divided into 9 groups according to 3 factors: particle (alumina vs alumina coated with silica), duration (5 vs 10 seconds), and distance (contact vs 10 mm away). All 3 factors significantly influenced the SR values between the experimental groups and the control group. For SBS, only the particle type was a statistically significant factor. Results showed that air particle abrasion with silica-coated alumina resulted in higher SBS, even though the SR values associated with those groups were not the highest.

Tooth erosion and dental caries in schoolchildren: is there a relationship between them?

AIM: To identify a possible association between the occurrence of dental caries and tooth erosion and to correlate the dietary factor with an increased risk of dental caries. METHODS: A cross-sectional study in a multistage random sample of 1,211, 8 to 12-years-old Brazilian schoolchildren in private and public schools was conducted in Pelotas, Brazil. The prevalence of dental caries and tooth erosion was assessed. Dietary habits data were collected by a structured questionnaire. Data were analyzed using Poisson regression model taking into account the cluster sample (Prevalence ratio - PR; 95% Confidence Interval - CI). RESULTS: The prevalence of dental caries and tooth erosion was 32.4% (95% CI: 30.0; 35.2) and 25.0% (95% CI: 23.4; 29.0), respectively. Most children had high consumption of sweets (65%). Consumption of fruits, such as oranges (31%), strawberries (23.6%), pineapple (12%), and natural fruit juices (oranges, lemon) was low. Soft drinks consumption, 3 or more times a week was observed in 40% of the children. CONCLUSIONS: Dental caries was not statistically associated with tooth erosion. The consumption of acidic fruits/drinks was not associated with dental caries. Dental caries and dental erosion were not associated with each other and with acidic fruits or drinks consumption.

Prosthetic rehabilitation of an edentulous patient with cleft palate.

It is difficult today to find older patients without their cleft palate prosthetically rehabilitated. This case report presents the rehabilitation by conventional dental prostheses of a cleft palate patient who had no prior treatment. A 52-year-old male presented himself to have his fissured palate obturated and occlusion restored. He reported difficulties in swallowing food and liquids, along with a severe speech disability. The patient's medical history revealed diabetes mellitus type II, hypertension, low vision due to macular atrophic lesions, and xerostomia. The upper and lower arches were completely and partially edentulous, respectively. The treatment plan involved a conventional denture to be placed in the upper arch, and a removable partial denture to be placed in the lower arch.

Radiopacity of restorative composites by conventional radiograph and digital images with different resolutions.

PURPOSE: This study was performed to evaluate and compare the radiopacity of dentin, enamel, and 8 restorative composites on conventional radiograph and digital images with different resolutions. MATERIALS AND METHODS: Specimens were fabricated from 8 materials and human molars were longitudinally sectioned 1.0 mm thick to include both enamel and dentin. The specimens and tooth sections were imaged by conventional radiograph using #4 sized intraoral film and digital images were taken in high speed and high resolution modes using a phosphor storage plate. Densitometric evaluation of the enamel, dentin, restorative materials, a lead sheet, and an aluminum step wedge was performed on the radiographic images. For the evaluation, the Al equivalent (mm) for each material was calculated. The data were analyzed using one-way ANOVA and Tukey's test (p<0.05), considering the material factor and then the radiographic method factor, individually. RESULTS: The high speed mode allowed the highest radiopacity, while the high resolution mode generated the lowest values. Furthermore, the high resolution mode was the most efficient method for radiographic differentiation between restorative composites and dentin. The conventional radiograph was the most effective in enabling differentiation between enamel and composites. The high speed mode was the least effective in enabling radiographic differentiation between the dental tissues and restorative composites. CONCLUSION: The high speed mode of digital imaging was not effective for differentiation between enamel and composites. This made it less effective than the high resolution mode and conventional radiographs. All of the composites evaluated showed radiopacity values that fit the ISO 4049 recommendations.

Type of resin cement influences microleakage in ceromer inlays? / Tipo de cimento resinoso influencia a micorinfiltração em inlays de cerômero?

Objective: To evaluate the influence of two resin cements on microleakage of ceromer inlays. Methods: Twenty recently extracted human third molars were selected. Standard inlay mesio-occluso-distal cavities were prepared, with cervical margin in enamel (mesial) or dentin (distal). The specimens were randomly divided into two groups (n=10) and indirect restorations were made with Belleglass HP system (Kerr, Romulus, MI, USA). The cavities in the first group were treated with adhesive system Single Bond and restorations were cemented with dual curing cement RelyX ARC (3M ESPE, St. Paul, MN, USA). In the second group, the ED Primer (Kuraray, Tokyo, Japan) was applied and indirect restorations were cemented with Panavia 21 EX (Kuraray, Tokyo, Japan). The specimens were coated with varnish, except for the restorations and 1 mm around them and submitted to thermal cycling and then immersed in 2% basic fuchsine solution for 24 hours. Teeth were sectioned longitudinally and leakage scores were evaluated using a stereomicroscope at 40x magnification. Data were submitted to statistical analysis (Mann-Whitney test). Results: Enamel showed lower dye penetration than dentin (p<0.05). Statistical difference between cements was only observed in enamel, with RelyX exhibiting less leakage (p<0.05). Conclusion: Within the limitations of the study, the substrate had a significant effect for sealing ability and RelyX ARC performed better than Panavia 21 EX only in enamel.

Objetivo: Avaliar a influência de dois cimentos resinosos sobre a microinfiltração de inlays de cerômero. Métodos: Vinte coroas de terceiros molars recentemente extraídos foram selecionadas.Cavidades do tipo Inlay padronizadas foram preparadas com a margem cervical em esmalte (mesial) ou dentina (distal). Os espécimes foram randomicamente distribuídos em dois grupos (n=10) e restaurações indiretas foram confeccionadas com o sistema Belleglass HP (Kerr, Romulus, MI, EUA). As cavidades do primeiro grupo foram tratadas com sistema adesivo Single Bond (3M ESPE, St. Paul, MN, USA) e as restaurações foram cimentadas com um cimento resinoso de cura dual (RelyX ARC, (3M ESPE, St. Paul, MN, EUA).No segundo grupo, ED Primer(Kuraray, Tokio, Japão)foi aplicado e as restaurações indiretas foram cimentadas com Panavia 21 EX (Kuraray, Tokio, Japão). Os espécimes foram pintados com verniz, exceto as restaurações e em torno de 1mm em volta destas,sendo então submetidos à termociclagem e imersos em solução de fucsina básica a 2% por 24 horas. Os dentes foram seccionados longitudinalmente e os escores de infiltração foram avaliados utilizando-se um estereomicroscópio com aumento de 40x. Os dados foram submetidos à análise estatística (teste de Mann-Whitney). Resultados: O esmalte apresentou menor infiltração de corante que a dentina (p<0.05). Diferenças estatística entre cimentos foram observadas apenas em esmalte, com o cimento RelyX ARC exibindo menor infiltração (p<0.05).Conclusão: Dentro das limitações deste estudo, observou-se que o substrato dentário apresentou um efeito significante para o selamento cavitário e o cimento RelyX ARC mostrou-se melhor que o Panavia 21 EX apenas em esmalte.

Influence of polishing procedures on the surface roughness of dental ceramics made by different techniques.

The aim of this study was to evaluate the influence of 2 different surface polishing procedures-glazing and manual polishing-on the roughness of ceramics processed by computer-aided design/computer-aided manufacturing (CAD/CAM) and conventional systems (stratification technique). Eighty ceramic discs (diameter: 8 mm, thickness: 1 mm) were prepared and divided among 8 groups (n = 10) according to the type of ceramic disc and polishing method: 4 GZ and 4 MP. Specimens were glazed according to each manufacturer's recommendations. Two silicone polishing points were used on the ceramic surface for manual polishing. Roughness was measured using a surface roughness tester. The roughness measurements were made along a distance of 2 mm on the sample surface and the speed of reading was 0.1 mm/s. Three measurements were taken for each sample. The data (µm) were statistically analyzed using analysis of variance (ANOVA) and Tukey's test (α = 0.05). Qualitative analysis was performed using scanning electron microscopy (SEM). The mean (± SD) roughness values obtained for GZ were: 1.1 ± 0.40 µm; 1.0 ± 0.31 µm; 1.6 ± 0.31 µm; and 2.2 ± 0.73 µm. For MP, the mean values were: 0.66 ± 0.13 µm; 0.43 ± 0.14 µm; 1.6 ± 0.55 µm; and 2.0 ± 0.63 µm. The mean roughness values were significantly affected by the ceramic type (P = 0.0001) and polishing technique (P = 0.0047). The SEM images confirmed the roughness data. The manually polished glass CAD/CAM ceramics promoted lower surface roughness than did the glazed feldspathic dental ceramics.

Desempenho Clínico de Restaurações Cerâmicas Livres de Metal: Revisão da Literatura / Clinical Service of Metal Free Restorations: Literature Review

O objetivo desse estudo foi avaliar, por meio deuma revisão de literatura, o desempenho clínico derestaurações livres de metal do tipo inlay/onlay, faceta, coroaunitária e prótese parcial fixa, destacando suas principaisfalhas, bem como a longevidade de cada tipo de restauração.Material e Métodos: A revisão sobre o tema, “Restauraçõescerâmicas livres de metal”, foi realizada utilizando asseguintes bases de dados: Medline, Portal Capes-Periódicos,Scielo, Bireme e BBO. Livros específicos sobre a temáticada pesquisa também foram consultados. Apenas artigospublicados entre 1990 e 2012 foram selecionados. Foramencontrados 400 artigos, dos quais, após criteriosa filtragem,selecionaram-se 70. Revisão da literatura: Verificou-se quea longevidade clínica das restaurações cerâmicas após 5anos de acompanhamento variou de acordo com o tipo derestauração: inlay/onlay (93 a 100%), faceta laminada (83 a100%), coroa unitária (91 a 100%) e prótese fixa (70 a 100%).Diversas falhas foram relatadas durante o uso clínico dessasrestaurações, entretanto, a principal foi a fratura da cerâmica,seguida de descolamento da cerâmica e cáries secundárias.Considerações finais: Pôde-se concluir que todos os tiposde restaurações apresentaram uma longevidade clínicaaceitável...

The objective of this study was to evaluate, througha literature review, the clinical performance of different metalfree ceramic restorations as inlay/onlay, veneer, crown andfixed partial denture, highlighting their major flaws and thelongevity of each type of restoration. Methodology: Thereview about the subject, “metal-free ceramic restorations,was performed using the following databases: Medline,Portal, Capes Periodicals, Scielo, Bireme and BBO. Books onspecific topics of research were also consulted. Only articlespublished between 1990 and 2009 were selected. It werefound 400 articles, of which selected after careful screeningis 83. Literature review: It was found that the clinical longevityof ceramic restorations after 5 years of follow up variedaccording to the type of restoration: inlay / onlay (93 to 100%),veneer ceramic (83 to 100%), single crown (91 to 100%)and fixed partial denture (70 to 100%). Several failures werereported during the clinical use of these restorations;however, the failure reported was the fracture of the ceramic,followed by the debonding of the ceramic and secondarycaries. Final considerations: It was observed that all kindsof restorations showed acceptable clinic longevity...

Novel experimental cements for use on the dentin-pulp complex.

This aim of this study was to evaluate the physicochemical and biological properties of novel experimental cements (Hybrid, Paste and Resin) based on synergistic combinations of existing materials, including pH, diametral tensile strength (DTS) and cytotoxicity comparing them with mineral trioxide aggregate (MTA - Angelus®) and a glass ionomer cement (GIC) developed at our laboratory. For the physicochemical and biological tests, specimens with standard dimensions were produced. pH measurements were performed with digital pH meter at the following time intervals: 3, 24, 48 and 72 h. For the DTS test, cylindrical specimens were subjected to compressive load until fracture. The MTT assay was performed for cytotoxicity evaluation. Data were analyzed by ANOVA and Tukey's test (α=0.05). Paste group showed pH values similar to MTA, and Hybrid group presented pH values similar to GIC (p>0.05). The tested materials showed pH values ranging from alkaline to near neutrality at the evaluated times. MTA and GIC showed similar DTS values. The lowest and highest DTS values were seen in the Paste and Resin groups, respectively (p<0.05). Cell viability for MTA and experimental Hybrid, Paste and Resin groups was 49%, 93%, 90% and 86%, respectively, when compared with the control group. The photo-cured experimental resin cement showed similar or superior performance compared with the current commercial or other tested experimental materials.

Elements of implant-supported rehabilitation planning in patients with bruxism.

The rehabilitation of partial or completely edentulous patients with implant-supported prostheses has been widely used, achieving high success rates. However, many studies consider the presence of bruxism as a contraindication for this treatment modality. The purpose of this study was to revise the literature and identify risk factors in implant-supported rehabilitation planning in subjects with bruxism. Available literature was searched through Medline, with no time limit, including only studies in English. Topics discussed were etiology of bruxism and its implications on dental implants, biomechanical considerations regarding the overload on dental implants, and methods to prevent the occurrence of overloads in implant-supported prostheses. The rehabilitation of bruxers using implant-supported prostheses, using implants with adequate length and diameter, as well as proper positioning seems to be a reliable treatment, with reduced risks of failure. Bruxism control through the use of a nightguard by rigid occlusal stabilization appliance relieved in the region of implants is highly indicated. Although it is clear that implant-supported rehabilitation of patients with bruxism requires adequate planning and follow-up, well-designed randomized controlled trials are needed to provide reliable evidence on the long-term success of this treatment modality.

Novel experimental cements for use on the dentin-pulp complex

This aim of this study was to evaluate the physicochemical and biological properties of novel experimental cements (Hybrid, Paste and Resin) based on synergistic combinations of existing materials, including pH, diametral tensile strength (DTS) and cytotoxicity comparing them with mineral trioxide aggregate (MTA - Angelus®) and a glass ionomer cement (GIC) developed at our laboratory. For the physicochemical and biological tests, specimens with standard dimensions were produced. pH measurements were performed with digital pH meter at the following time intervals: 3, 24, 48 and 72 h. For the DTS test, cylindrical specimens were subjected to compressive load until fracture. The MTT assay was performed for cytotoxicity evaluation. Data were analyzed by ANOVA and Tukey's test (α=0.05). Paste group showed pH values similar to MTA, and Hybrid group presented pH values similar to GIC (p>0.05). The tested materials showed pH values ranging from alkaline to near neutrality at the evaluated times. MTA and GIC showed similar DTS values. The lowest and highest DTS values were seen in the Paste and Resin groups, respectively (p<0.05). Cell viability for MTA and experimental Hybrid, Paste and Resin groups was 49%, 93%, 90% and 86%, respectively, when compared with the control group. The photo-cured experimental resin cement showed similar or superior performance compared with the current commercial or other tested experimental materials.

O objetivo deste estudo foi avaliar propriedades físico-químicas e biológicas de novos cimentos experimentais (Híbrido, Pasta e Resinoso) baseado na combinação sinérgica de materiais existentes, incluindo pH, resistência à tração diametral (RTD) e citotoxidade, comparando-os ao MTA (Angelus®) e a um cimento de ionômero de vidro (CIV) desenvolvido em nosso laboratório. Para a realização dos testes físico-mecânico e biológico, foram confeccionados espécimes com dimensões padrão. O teste de pH foi realizado por meio de pH-metro digital nos tempos: 3, 24, 48 e 72 h. Para o teste de RTD, espécimes cilíndricos foram submetidos a carga compressiva até sua fratura. Para avaliação da citotoxidade, utilizou-se o teste MTT. Os dados foram analisados utilizando ANOVA e teste de Tukey (α=0,05). O grupo Pasta apresentou valores de pH semelhantes ao MTA, assim como o grupo Híbrido seguiu os parâmetros do CIV (p>0,05). Todos os materiais apresentaram valores de pH alcalinos ou próximosà neutralidade nos tempos avaliados. MTA e CIV apresentaram valores de RTD similares. Os menores e maiores valores observados foram do grupo Pasta e Resinoso, respectivamente (p<0,05). A viabilidade celular para os grupos MTA, Híbrido, Pasta, Resinoso, quando comparados ao grupo controle foi de: 49, 93, 90 e 86%, respectivamente. O cimento experimental Resinoso apresentou desempenho similar ou superior aos materiais comerciais e experimentais avaliados.

Erosion and abrasion on dental structures undergoing at-home bleaching.

This review investigates erosion and abrasion in dental structures undergoing at- home bleaching. Dental erosion is a multifactorial condition that may be idiopathic or caused by a known acid source. Some bleaching agents have a pH lower than the critical level, which can cause changes in the enamel mineral content. Investigations have shown that at-home tooth bleaching with low concentrations of hydrogen or carbamide peroxide have no significant damaging effects on enamel and dentin surface properties. Most studies where erosion was observed were in vitro. Even though the treatment may cause side effects like sensitivity and gingival irritation, these usually disappear at the end of treatment. Considering the literature reviewed, we conclude that tooth bleaching agents based on hydrogen or carbamide peroxide have no clinically significant influence on enamel/dentin mineral loss caused by erosion or abrasion. Furthermore, the treatment is tolerable and safe, and any adverse effects can be easily reversed and controlled.

Influência de Protocolos de Jateamento na Rugosidade da Superfície de uma Cerâmica de Zircônia Tetragonal Parcialmente Estabilizada por Ítria / Influence of Air Abrasion Protocols on the Surface Roughness of an Yttria Partially Stabilized Tetragonal Zirconia Ceramic

Objetivo: Avaliar a influência de diferentes protocolos de jateamento na rugosidade superficial de uma cerâmica policristalina de zircônia tetragonal estabilizada com ítria(Y-TZP), assim como a topografia superficial da cerâmica após o tratamento.Método: A partir de dois blocos cerâmicos (LAVA, 3M ESPE), obtiveramse 54 espécimes (7,5x4x7,5mm), sendo estes regularizados com lixas dÆágua em granulação fina e sinterizados em forno específico do sistema cerâmico. Em seguida, os corpos de prova foram incluídos em resina acrílica e as superfícies a serem tratadas foram lixadas em politriz com lixas dÆágua em granulação decrescente (600 a 1.200), associadas a pastas de polimento de 10µm, 3µm e sílica coloidal em disco de feltro, sendo distribuídas aleatoriamente em 9 grupos, de acordo com os fatores ôpartículaõ e ôpressãoõ(n=6): Gr1- controle; Gr2-Al2O3(50µm)/2,5bar; Gr3- Al2O3(110µm)/2,5 bar; Gr4-SiO2(30µm)/2,5bar; Gr5- SiO2(30µm)/2,5bar; Gr6- Al2O3(50µm)/3,5bar; Gr7- Al2O3(110µm)/3,5bar; Gr8- SiO2(30µm)/3,5bar; Gr9-SiO2(30µm)/3,5bar. Após os tratamentos, a rugosidade das superfícies foi analisada por meio de um perfilômetro óptico digital e a morfologia, por meio de Microscopia Eletrônica de Varredura (MEV). Os dados (µm) obtidos foram submetidos à análise estatística por meio do teste de Dunnett (5%), ANOVA (2 fatores) e teste de Tukey (5%).Resultados: O tipo de partícula (p=0,0001) e a pressão (p=0,0001) utilizada no jateamento influenciaram os valores de rugosidade entre os grupos experimentais (ANOVA).

Os valores médios de rugosidade (µm) obtidos para os grupos experimentais (Gr2 a Gr9) foram, respectivamente: 0,37D; 0,56BC; 0,46BC; 0,48CD; 0,59BC; 0,82A; 0,53BCD; 0,67AB. A análise em MEV revelou que o Al2O3, independente do tamanho das partículas e da pressão utilizada, danificou a superfície dos espécimes, uma vez que foram observados danos superficiais na cerâmica, na forma de ranhuras e de lascamentos.Conclusão: O jateamento com Al2O3(110µm)/3,5bar foi o tratamento que promoveu a maior rugosidade nas superfícies cerâmicas, embora não signifique que este protocolo promova melhor união cerâmicacimento em relação aos demais tipos de jateamento

Objective: To evaluate the influence of different air abrasion protocols on the surface roughness of an yttria-stabilized polycrystalline tetragonal zirconia) (Y-TZP) ceramic, as well as the surface topography of the ceramic after the treatment. Method: Fifty-four specimens (7.5x4x7.5mm) obtained from two ceramic blocks (LAVA, 3M ESPE) were flattened with fine-grit sandpaper and subjected to sintering in the ceramic systemÆs specific firing oven. Next, the specimens were embedded in acrylic resin and the surfaces to be treated were polished in a polishing machine using sandpapers of decreasing abrasion (600- to 1,200-grit) followed by felt discs with 10µm and 3µm polishing pastes and colloidal silica. The specimens were then randomly assigned to 9 groups, according to factors ôparticleõ and ôpressureõ(n=6): Gr1- control; Gr2-Al2O3(50µm)/2.5 bar; Gr3- Al2O3(110µm)/2.5 bar; Gr4- SiO2(30µm)/2.5 bar; Gr5- SiO2(30µm)/2.5 bar; Gr6- Al2O3(50µm)/3.5 bar; Gr7-Al2O3(110µm)/3.5 bar; Gr8- SiO2(30µm)/3.5 bar; Gr9- SiO2(30µm)/3.5 bar. After treatments, surface roughness was analyzed by a digital optical profilometer and the morphology was examined by scanning electron microscopy (SEM). Data (µm) were subjected to statistical analysis by DunnettÆs test (5%), two-way ANOVA and TukeyÆs test (5%).Results: The type of particle (p=0.0001) and the pressure (p=0.0001) used in the air abrasion protocols influenced the surface roughness values among the experimental groups (ANOVA).

The mean surface roughness values (µm) obtained for the experimental groups (Gr2 to Gr9) were, respectively: 0.37D; 0.56BC; 0.46BC; 0.48CD; 0.59BC; 0.82A; 0.53BCD; 0.67AB. The SEM analysis revealed that Al2O3, regardless of the particle size and pressure used, caused damage to the surface of the specimens, as it produced superficial damages on the ceramic, in the form of grooves and cracks. Conclusion: Al2O3 (110 µm/3.5 bar) air abrasion promoted the highest surface roughness on the ceramics, but it does not mean that this protocol promotes better ceramic-cement union compared to the other air abrasion protocols

Influência de Diferentes Sistemas Adesivos na Resistência de União de Pinos de Fibra à Dentina Intrarradicular / Influence of Different Adhesive Systems on the Bond Strength of Fiber Post to Root Dentin

Objetivo: Avaliar a influência de três sistemas adesivos na resistência de união ao push-out de pinos de fibra cimentados adesivamente à dentina radicular. A hipótese foi de que a resistência de união varia em função do tipo de sistema adesivo. Método: Os canais de 30 dentes bovinos unirradiculares (16mm de comprimento) foram preparados com brocas específicas (FGM) até 12mm. 14 mm de cada raiz foi incluída em resina acrílica e divididas em 3 grupos (n=10), de acordo com o fator ôadesivoõ (3 níveis): Gr1-Scotchbond Multipurpose Plus (3M ESPE), Gr2- One Step (Bisco) and Gr3- Excite DSC (Ivoclar). Os sistemas adesivos foram aplicados com um microbrush, seguindo as recomendações do fabricante. Os pinos de fibra (White Post DC, FGM) foram cimentados com cimento resinoso dual (All-Cem, FGM). Após, os núcleos de resina composta (Llis, FGM) foram confeccionados e cada conjunto raiz/pino/núcleo foi submetido à ciclagem mecânica (Erios, Brazil) (106ciclos, 84N, 4 Hz, inclinação de 45º, 37ºC, sob refrigeração constante). Cada espécime foi seccionado em quatro fatias (1.8mm), as quais foram submetidas ao teste push-out em máquina de ensaio universal (ServoPulser û Shimadzu) (50Kgf, 1mm/min). Os dados (MPa) foram analisados utilizando ANOVA (1-way) e Tukey test (5%). Resultados: O fator ôadesivoõ (p= 0,0352) influenciou significantemente a força de união (ANOVA). O Gr1 (6,8±3,8 MPa)aapresentou valores de resistência de união superior ao Gr2 (3,1±1,5 MPa)be semelhantes ao Gr3 (4,4±3,3)a,b. Além disso, Gr3 e Gr2 foram semelhantes entre si (Tukey). A hipótese foi aceita. Conclusão: Baseado nos resultados concluiu-se que os sistemas adesivos com polimerização química e dual devem ser os selecionados para procedimentos de cimentação adesiva de pinos de fibra

Objective: To evaluate the influence of three adhesive systems on the bond strength of fiber post luted to root dentine. The hypothesis was that the bond strength is influenced by the adhesive system. Method: The canals of thirty single-root bovine roots (16mm in length) were prepared using the preparation drill (FGM) until 12mm. 14 mm of each root was embedded with acrylic resin and the specimens were allocated into three groups (n=10), considering the factor ôadhesiveõ (3 levels): Gr1- Scotchbond Multipurpose Plus (3M ESPE), Gr2- One Step (Bisco) and Gr3- Excite DSC (Ivoclar Vivadent). The adhesive systems were applied using a microbrush, according to the manufactureÆs recommendations. The fiber posts (White Post DC, FGM) were luted with dual resin cement (All-Cem,FGM). After, the cores with composite resin (Llis, FGM) were made and each set of root/post/core was submitted to the mechanical cycling (Erios, Brazil) (106cycles, 84N, 4 Hz, inclination of 45º, 37ºC, water). Each specimen was cut in 4 samples (1.8mm in thickness), which were submitted to the push-out test in a universal testing machine (ServoPulser û Shimadzu) (50Kgf, 1mm/min). The data (MPa) were analyzed using ANOVA (1-way) and Tukey test (5%). Results: The factor ôadhesiveõ (P=0.00352) influenced the bond strength significantly (ANOVA). Gr1 (6.8±3.8 MPa)apresented higher bond strength values than Gr2 (3.1±1.5 MPa)band similar to Gr3 (4.4±3.3)a,b. Moreover, Gr3 and Gr2 were similar between them (Tukey). The hypothesis was accepted. Conclusion: Based on the results it was concluded that chemical and dual polymerization adhesive system should be used for the adhesive luting fiber post procedures