ABSTRACT
Abstract Objective This study aims to evaluate the influence of different air-abrasion pressures and subsequent heat treatment on the flexural strength, surface roughness, and crystallographic phases of highly translucent partially stabilized zirconia (Y-PSZ), and on the tensile bond strength of resin cement to Y-PSZ. Methodology Fully sintered zirconia specimens were ground with SiC paper (control) and/or air-abraded with 50 µm particles of alumina at 0.1, 0.15, 0.2, or 0.3 MPa or left as-sintered. After air-abrasion at 0.2 MPa (0.2AB), additional specimens were then heated to 1500°C, and held for one hour at this temperature (0.2AB+HT1h). Flexural strength and surface roughness were evaluated. Crystalline phase identification was also carried out using X-ray diffraction. Bonded zirconia specimens with self-adhesive resin cement were stored in distilled water at 37°C for 24 h, either with or without aging (thermal cycling 4-60°C/20000). Results were analyzed statistically by ANOVA and Tukey-Kramer tests. Results The flexural strength decreased with the increase in air-abrasion pressure, while in contrast, the surface roughness increased. The lowest flexural strength and the highest roughness value were found for the 0.2AB and 0.3AB groups, respectively. All groups contained cubic-, tetragonal ( t )-, and rhombohedral ( r )-ZrO2 phases with the exception of the as-sintered group. Upon increasing the air-abrasion pressure, the relative amount of the r -ZrO2 phase increased, with a significant amount of r -ZrO2 phase being detected for the 0.2AB and 0.3AB groups. The 0.2AB+HT1h group exhibited a similar flexural strength and t -ZrO2 phase content as the as-sintered group. However, the 0.2AB group showed a significantly higher tensile bond strength (p<0.05) than the 0.2AB+HT1h group before and after aging. Conclusion Micromechanical retention by alumina air-abrasion at 0.2 MPa, in combination with chemical bonding of a resin to highly translucent Y-PSZ using a MDP-containing resin cement may enable durable bonding.
Subject(s)
Zirconium/chemistry , Dental Bonding/methods , Resin Cements/chemistry , Air Abrasion, Dental/methods , Aluminum Oxide/chemistry , Reference Values , Surface Properties , Tensile Strength , X-Ray Diffraction/methods , Materials Testing , Reproducibility of Results , Analysis of Variance , Microscopy, Confocal/methods , Flexural Strength , Hot TemperatureABSTRACT
Abstract Objective This study aims to evaluate the effect of sonochemical treatment on the surface of yttria-stabilized tetragonal zirconia (Y-TZP) before and after the final sintering. Material and Methods Twenty-eight Y-TZP discs were divided into four groups (n=7), according to surface treatment: PRE: pre-sintering sonication with 30% nominal power for 15 min; POS: post-sintering sonication with 30% nominal power for 15 min; JAT: air abrasion with 50-μm alumina particles; and CON: control group with no treatment. The POS and JAT groups were sintered before sonication and the PRE group after sonication. Surface roughness was analyzed using confocal microscopy, after which resin cement cylinders were placed on the surface of the Y-TZP discs and subjected to mechanical microshear bond strength test until fracture. Surface roughness and microshear bond strength values underwent ANOVA and the Tukey tests. Results The surface roughness values for the PRE group (299.91 nm) and the POS group (291.23 nm) were not significantly different (p≥0.05), statistically, and the surface roughness value of the JAT group (925.21 nm) was higher than those of PRE and POS (p=0.007) groups. The mechanical microshear bond strength test showed that there was no statistically significant difference between the groups (p=0.08). Conclusions Therefore, the results showed that sonochemical treatment modifies the Y-TZP surface and is similar to the well-established sandblasting surface treatment regarding the strength of the bond with the resin cement.
Subject(s)
Yttrium/chemistry , Zirconium/chemistry , Dental Bonding/methods , Resin Cements/chemistry , Reference Values , Surface Properties , Materials Testing , Reproducibility of Results , Analysis of Variance , Statistics, Nonparametric , Air Abrasion, Dental , Shear StrengthABSTRACT
Abstract Objectives: To evaluate the effects of dentin pretreatment and temperature on the bond strength of a universal adhesive system to dentin. Material and Methods: Ninety-six extracted non-carious human third molars were randomly divided into 12 groups (n=8) according to Scotchbond Universal Adhesive (SbU) applied in self-etch (SE) and etch-and-rinse (ER) mode, adhesive temperature (20°C or 37°C) and sodium bicarbonate or aluminum oxide air abrasion. After composite build up, bonded sticks with cross-sectional area of 1 mm2 were obtained to evaluate the microtensile bond strength (μTBS). The specimens were tested at a crosshead speed of 0.5 mm/min on a testing machine until failure. Fractured specimens were analyzed under stereomicroscope to determine the failure patterns in adhesive, cohesive (dentin or resin) and mixed fractures. The microtensile bond strength data was analyzed using two-way ANOVA and Tukey's test (α=5%). Results: Interaction between treatment and temperature was statistically significant for SbU applied in self-etch technique. Both dentin treatments showed higher bond strength for ER mode, regardless of adhesive temperature. When compared to control group, sodium bicarbonate increased bond strength of SbU in SE technique. Adhesive temperature did not significantly affect the μTBS of tested groups. Predominantly, adhesive failure was observed for all groups. Conclusions: Dentin surface treatment with sodium bicarbonate air abrasion improves bond strength of SbU, irrespective of adhesive application mode, which makes this approach an alternative to increase adhesive performance of Scotchbond Universal Adhesive to dentin.
Subject(s)
Humans , Temperature , Dental Bonding/methods , Dentin-Bonding Agents/chemistry , Resin Cements/chemistry , Tooth Preparation/methods , Dentin/drug effects , Surface Properties/drug effects , Tensile Strength , Materials Testing , Reproducibility of Results , Analysis of Variance , Sodium Bicarbonate/chemistry , Statistics, Nonparametric , Composite Resins/chemistry , Dental Restoration Failure , Air Abrasion, Dental/methodsABSTRACT
O objetivo deste artigo é avaliar a percepção de responsáveis sobre fatores preditores do medo odontológico e aceitação do uso de uma nova tecnologia para remoção do tecido cariado em suas crianças. Entrevista a partir de um questionário semiestruturado com 105 responsáveis por crianças, de 2 a 12 anos, atendidas na Clínica de Odontopediatria, a respeito do nível de medo/apreensão, conhecimento e importância de novos estudos e autorização para utilização de novas tecnologias. Os dados foram analisados descritivamente e utilizando o teste Exato de Fisher (p<0,05). Embora os responsáveis tenham poucas informações sobre os métodos alternativos de remoção de cárie, eles são receptivos ao uso dos mesmos em seus filhos.
The purpose this article is to evaluate the caregivers'perception of predictors of dental fear and acceptance of use a new technology for removal of caries in their children. Interview using a semi-structured questionnaire with 105 caregivers for children 2 to 12 years attending at Clinic of Pediatric Dentistry. The data were about dental fear/ apprehension; knowledge and importance of new studies and permission to use new technologies. Data were analyzed descriptive and using the Fishers Exact test (p <0.05). A lthough t he c aregivers have little information about alternative methods of caries removal, they are receptive to use them in their children.
Subject(s)
Child , Dental Anxiety , Air Abrasion, DentalABSTRACT
OBJECTIVE: To assess microleakage in conservative class V cavities prepared with aluminum-oxide air abrasion or turbine and restored with self-etching or etch-and-rinse adhesive systems. Materials and Methods: Forty premolars were randomly assigned to 4 groups (I and II: air abrasion; III and IV: turbine) and class V cavities were prepared on the buccal surfaces. Conditioning approaches were: groups I/III - 37 percent phosphoric acid; groups II/IV - self-priming etchant (Tyrian-SPE). Cavities were restored with One Step Plus/Filtek Z250. After finishing, specimens were thermocycled, immersed in 50 percent silver nitrate, and serially sectioned. Microleakage at the occlusal and cervical interfaces was measured in mm and calculated by a software. Data were subjected to ANOVA and Tukey's test (α=0.05). RESULTS: Marginal seal provided by air abrasion was similar to high-speed handpiece, except for group I. There was SIGNIFICANT difference between enamel and dentin/cementum margins for to group I and II: air abrasion. The etch-and-rinse adhesive system promoted a better marginal seal. At enamel and dentin/cementum margins, the highest microleakage values were found in cavities treated with the self-etching adhesive system. At dentin/cementum margins, high-speed handpiece preparations associated with etch-and-rinse system provided the least dye penetration. CONCLUSION: Marginal seal of cavities prepared with aluminum-oxide air abrasion was different from that of conventionally prepared cavities, and the etch-and-rinse system promoted higher marginal seal at both enamel and dentin margins.
Subject(s)
Humans , Air Abrasion, Dental/methods , Dental Cavity Preparation/methods , Dental Leakage/classification , Acid Etching, Dental/methods , Aluminum Oxide/chemistry , Composite Resins/chemistry , Dental Bonding , Dental High-Speed Equipment , Dental Marginal Adaptation , Dental Polishing , Dental Cavity Preparation/instrumentation , Dental Cementum/ultrastructure , Dental Enamel/ultrastructure , Dental Restoration, Permanent/methods , Dentin-Bonding Agents/chemistry , Dentin/ultrastructure , Materials Testing , Methacrylates/chemistry , Phosphoric Acids/chemistry , Silver Staining , Surface Properties , TemperatureABSTRACT
This study evaluated the influence of surface treatment on the shear bond strength of a composite resin (CR), previously submitted to the application of a temporary cement (TC), to an adhesive luting cement. Eight-four CR cylinders (5 mm diameter and 3 mm high) were fabricated and embedded in acrylic resin. The sets were divided into 6 groups (G1 to G6) (n=12). Groups 2 to 6 received a coat of TC. After 24 h, TC was removed and the CR surfaces received the following treatments: G2: ethanol; G3: rotary brush and pumice; G4: air-abrasion; G5: air-abrasion and adhesive system; G6: air-abrasion, acid etching and adhesive system. G1 (control) did not receive TC or any surface treatment. The sets were adapted to a matrix and received an increment of an adhesive luting cement. The specimens were subjected to the shear bond strength test. ANOVA and Tukeyʼs tests showed that G3 (8.53 MPa) and G4 (8.63 MPa) differed significantly (p=0.001) from G1 (13.34 MPa). The highest mean shear bond strength values were found in G5 (14.78 MPa) and G6 (15.86 MPa). Air-abrasion of CR surface associated with an adhesive system provided an effective bond of the CR to the adhesive luting cement, regardless the pre-treatment with the phosphoric acid.
A influência do tratamento de superfície sobre a resistência adesiva entre uma resina composta (RC), previamente submetida à aplicação de um cimento temporário (CT), e um cimento resinoso foi avaliada. Oitenta e quatro cilindros de RC (5 mm de diâmetro e 3 mm de altura) foram confeccionados e incluídos em resina acrílica. Os conjuntos foram divididos em 6 grupos (G1 a G6) (n=12). Os grupos de 2 a 6 receberam uma camada do CT. Após 24 h, o CT foi removido e as superfícies de RC receberam os seguintes tratamentos: G2: limpeza com etanol; G3: limpeza com escova rotatória e pedra pomes; G4: jateamento ; G5: jateamento e aplicação de adesivo; G6: jateamento, condicionamento ácido e adesivo. O G1(controle) não recebeu CT ou nenhum tratamento de superfície. Os conjuntos foram adaptados à matriz e receberam incremento de cimento resinoso. Os corpos de prova foram submetidos ao ensaio de cisalhamento. Os testes ANOVA e Tukey (p=0,001), demonstraram que os grupos G3 (8,53 MPa) e G4 (8,63 MPa) diferiram estatisticamente do grupo G1 (13,34 MPa). As maiores valores médios de resistência ao cisalhamento foram encontradas nos grupos G5 (14,78 MPa) e G6 (15,86 MPa). O jateamento da superfície da resina composta associado a um sistema adesivo, independente do pré-tratamento com o ácido fosfórico, proporcionou uma efetiva união ao cimento resinoso.
Subject(s)
Air Abrasion, Dental/methods , Composite Resins , Dental Cements , Dental Bonding/methods , Shear Strength , Analysis of Variance , Dental Stress Analysis , Dental Restoration, Temporary/methods , Light-Curing of Dental Adhesives , Statistics, Nonparametric , Surface PropertiesABSTRACT
Apesar de a resina composta ser amplamente conhecida e utilizada com sucesso na confecção das restaurações, em alguns casos há necessidade de reparos, os quais exigem menos desgastes dentário em comparação à substituição total das restaurações. Dessa forma, o presente trabalho tem como objetivo revisar os principais procedimentos e materiais utilizados na confecção dos reparos de resina composta, assim como os testes que avaliam a força de adesão de tais procedimentos. Meios químicos e mecânicos, isolados ou associados, tem sido propostos para analisar a força de adesão ao reparo, como a utilização do ácido fluorídrico, ácido fosfórico, jateamento de óxido de alumínio, pontas diamantadas, adesivos e silano. Com base na literatura revisada, observou-se a importância do tratamento da superfície da resina a ser reparada e concluiu-se que o jateamento com óxido de alumínio, seguido da aplicação do ácido fosfórico e do adesivo foi o modo mais eficaz de seconseguir sucesso nos reparos de resina composta.
Although the composites being widely known and used with success in the restorations, in some cases repairs are necessary, which demand less dental waste in comparison with the total substitution of the restorations. In that way, the aim of this work was to review the main procedures and materials used in repairs of composites, as well as the explaining of the tests that evaluated the bond strength of such procedures. A number of techniques have been proposed to improve bond strength of composite repair through roughening, etching the substrate surface with acidulated phosphate fluoride, HF acid gel, air-borne particle abrasion or using adhesive resins. Based on the reviewed bibliography, the importance of the treatment of the surface was observed from the resin to be repaired, and it was concluded that the air-borne particle abrasion was the most effective way for composites, followed by the application of the HF acid gel and adhesive resins.
Subject(s)
Air Abrasion, Dental , Composite Resins , Dental Materials , Dental Restoration WearABSTRACT
O estudo, de desenho transversal, teve como objetivo levantar a prevalência de sobrepeso e obesidade em trabalhadores de cozinhas (n = 200) de oito hospitais públicos localizados na grande Florianópolis, Santa Catarina, verificando se há algum fator de risco específico relacionado às condições de trabalho. Utilizaram-se, como grupo de comparação, trabalhadores das lavanderias (n =178) dos mesmos hospitais. Os dados foram coletados através de questionário estruturado e levantamento de medidas de peso e estatura. A prevalência de sobrepeso e obesidade (IMC 25 kg/m2) foi maior entre os trabalhadores de cozinhas, encontrando-se associação positiva entre as mulheres (RP = 1,3; IC 95% = 1,1 a 1,5). A variável beliscar alimentos no local de trabalho mostrou se condição específica dos trabalhadores de cozinhas independentemente do sexo, sendo que os homens e as mulheres das cozinhas beliscam alimentos freqüentemente no trabalho 5,7 e 3,9 vezes mais que os homens e mulheres das lavanderias, respectivamente. Sendo assim, o acesso ao alimento pode estar relacionado à manutenção do excesso de peso e a maiores médias de peso entre as mulheres.
The aim of this study is to check the prevalence of overweight and/or obesity in kitchen workers and to observe if there is any specific risk factor related to their working conditions. It is a cross-sectional study with all the kitchen (n =200) and laundry (n = 178) workers of eight public hospitals in Florianópolis, Santa Catarina, a state located in the South of Brazil. Collecting of data included checking their weighs and measures and their answers to a questionnaire. The prevalence of overweight and obesity (BM I? 25 kg/m2) was higher among kitchen workers; a positive association was found for females only (Prevalence Rate Ratio = 1,3; 95% CI; 1,1; 1,5). The variable food snacking in the workplace was found to be typical for kitchen workers, either male or female. It was also found that both male and female kitchen workers frequently snack 5.7 and 3.9 more in the workplace than laundry workers. The easy access to food may be the reason for the highest weight levels among women
ABSTRACT
Objectives:To evaluate the adhesive effect of resin and dentin perpared by air abrasion. Methods:Dentin of 48 permanent molars was exposed and treated with ① air sand blasting+whole acid corrosion+Estet. X TM,② air sand blasting+SE BOND,③ air sand blasting+Esthet. X TM,④Turbine+whole acid corrosion+Esthet.X TM respectively with 12 samples in each group. Then resin adhesive was applied.Microtensile testing was used to examine the microtensile bond strength. SEM was used to observe the change of resin jags. Results:The microtensile bonding strength in group ①,②,③ and ④ was 27.96?1.42, 29.84?2.56,14.48?2.45 and 27.73?1.48 respectively (① vs ③,② vs ③ and ③ vs ④ P