Influence of alumina air-abrasion for highly translucent partially stabilized zirconia on flexural strength, surface properties, and bond strength of resin cement

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.

Dentin pretreatment and adhesive temperature as affecting factors on bond strength of a universal adhesive system

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.

Effects of air abrasion with alumina or glass beads on surface characteristics of CAD/CAM composite materials and the bond strength of resin cements

ABSTRACT Objective The study aimed to evaluate effects of air abrasion with alumina or glass beads on bond strengths of resin cements to CAD/CAM composite materials. Material and Methods CAD/CAM composite block materials [Cerasmart (CS) and Block HC (BHC)] were pretreated as follows: (a) no treatment (None), (b) application of a ceramic primer (CP), (c) alumina-blasting at 0.2 MPa (AB), (d) AB followed by CP (AB+CP), and (e) glass-beads blasting at 0.4 MPa (GBB) followed by CP (GBB+CP). The composite specimens were bonded to resin composite disks using resin cements [G-CEM Cerasmart (GCCS) and ResiCem (RC)]. The bond strengths after 24 h (TC 0) and after thermal cycling (TC 10,000 at 4–60°C) were measured by shear tests. Three-way ANOVA and the Tukey compromise post hoc tests were used to analyze statistically significant differences between groups (α=0.05). Results For both CAD/CAM composite materials, the None group exhibited a significant decrease in bond strength after TC 10,000 (p<0.05). AB showed significantly higher bond strength after TC 10,000 than the None group, while CP did not (p<0.05). GBB exhibited smaller surface defects than did AB; however, their surface roughnesses were not significantly different (p>0.05). The AB+CP group showed a significantly higher bond strength after TC 10,000 than did the AB group for RC (p<0.05), but not for GCCS. The GBB+CP group showed the highest bond strength for both thermal cyclings (p<0.05). Conclusions Air abrasion with glass beads was more effective in increasing bond durability between the resin cements and CAD/CAM composite materials than was using an alumina powder and a CP.

Influence of surface treatment on shear bond strength of orthodontic brackets

INTRODUCTION: The shear bond strength of orthodontic brackets bonded to micro-hybrid and micro-particulate resins under different surface treatment methods was assessed. METHODS: Two hundred and eighty test samples were divided into 28 groups (n = 10), where 140 specimens were filled with Durafill micro-particulate resin and 140 with Charisma composite. In 140 samples, a coupling agent (silane) was applied. The surface treatment methods were: Phosphoric and hydrofluoric acid etching, sodium bicarbonate and aluminum oxide blasting, stone and burs. A Universal Instron Machine was used to apply an occlusal shear force directly to the resin composite bracket surface at a speed of 0.5 mm/min. The means were compared using analysis of variance and multivariate regression to assess the interaction between composites and surface treatment methods. RESULTS: Means and standard deviations for the groups were: Sodium bicarbonate jet 11.27±2.78; burs 9.26±3.01; stone 7.95±3.67; aluminum oxide blasting 7.04±3.21; phosphoric acid 5.82±1.90; hydrofluoric acid 4.54±2.87, and without treatment 2.75±1.49. An increase of 1.94 MPa in shear bond strength was seen in Charisma groups. Silane agent application reduced the Charisma shear bond strength by 0.68 Mpa, but increased Durafill means for bicarbonate blasting (0.83), burs (0.98) and stone drilling (0.46). CONCLUSION: The sodium bicarbonate blasting, burs and stone drilling methods produced adequate shear bond strength and may be suitable for clinical use. The Charisma micro hybrid resin composite showed higher shear bond means than Durafill micro particle composite.

INTRODUÇÃO: foram avaliadas as forças de cisalhamento após colagem de braquetes ortodônticos em superfícies resinosas microparticuladas ou micro-híbridas, após diferentes tratamentos de superfície. MÉTODOS: foram utilizados 280 corpos de prova, divididos em grupos de 10 elementos cada, sendo 140 preenchidos com resina microparticulada Durafill e 140 com resina micro-híbrida Charisma. Os tratamentos de superfície envolveram: ácido fosfórico, ácido fluorídrico, jato de bicarbonato de sódio, jato de óxido de alumínio, pedra e broca. A silanagem foi utilizada em metade dos grupos. O cisalhamento foi realizado com a máquina universal de testes EMIC DL 10000 MF, com célula de 10kg e velocidade de 0,5mm/min. As comparações entre as forças de cisalhamento foram obtidas por meio da análise de variância, e o grau de interação entre os tipos de compósito e o preparo de superfície foram obtidos por meio de uma regressão multivariada. RESULTADOS: as médias e desvios-padrão foram: jato de bicarbonato = 11,27 ± 2,78; broca = 9,26 ± 3,01; pedra = 7,95 ± 3,67; jato de óxido de alumínio = 7,04 ± 3,21; ácido fosfórico = 5,82 ± 1,90; ácido fluorídrico = 4,54 ± 2,87; e sem preparo = 2,75 ± 1,49. Um acréscimo de 1,94MPa foi obtido com o uso do compósito Charisma. A silanagem reduziu em 0,68MPa as médias do compósito Charisma, e aumentou o Durafill com uso do jato de bicarbonato (0,83), broca (0,98) e pedra (0,46). CONCLUSÃO: os preparos com jato de bicarbonato, broca e pedra obtiveram médias de forças apropriadas para colagem. O compósito Charisma apresentou forças de maior intensidade que as da resina Durafill.

In vitro study of microleakage of different techniques of surface preparation used in pits and fissures.

Objective : The purpose of this in vitro study was to evaluate the effect of different techniques of surface preparation on the microleakage of a sealant applied with traditional acid etching and self-etched bonding agent. Study Design : A total of 60 extracted third molars were randomly assigned into six groups (n = 10/each). The occlusal surfaces were sealed with a sealant (Clinpro) after one of the following pretreatments: (1) phosphoric acid etching; (2) Prompt L-Pop; (3) laser + etching; (4) laser + Prompt L-Pop; (5) air abrasion + etching; (6) air abrasion + Prompt L-Pop. The specimens were immersed in a 0.5% basic fuchsin solution. Buccolingual cuts parallel to the long axis of the tooth were made. The surfaces were scored 0--2 for extent of microleakage using a microscope and the data were analyzed statistically. Results : The poorest results were obtained with laser + Prompt L-Pop which showed a greater number of specimens with microleakage (80%). Air abrasion surface preparation + phosphoric acid etching showed less microleakage than the other groups (40%). Kruskal--Wallis and t-tests revealed no significant difference in microleakage between six groups. Conclusion : The self-etching adhesive studied seems an attractive alternative to the acid-etch technique for sealant application in young children where simplifications in the clinical procedure are warranted. No significant difference was noted between the different types of enamel preparation before fissure sealant.

The effect of air abrasion on the retention of metallic brackets bonded to fluorosed enamel surface.

Background: Bonding brackets to fluorosed enamel remains a clinical challenge and bracket failure at the compromised enamel interface is common. Objective: To check the effect of air abrasion on the retention of metallic brackets bonded to fluorosed enamel surface. Materials and Methods: Sixty freshly extracted human premolar teeth having moderate to severe dental fluorosis as per Dean's criteria were collected and divided into three groups of 20 each. The groups were treated as follows: In group I, acid etching was followed by bonding with Transbond XT® ; in group II, sandblasting and acid etching was followed by bonding with Transbond XT® ; and in group III, sandblasting and acid etching was followed by bonding with Enlight LC® . An Instron™ universal testing machine was used for determining the debonding force, and from this the shear bond strength was computed. The sample with highest shear bond strength from each group was selected for the scanning electron microscopy (SEM) study. The prepared specimens were examined under a JSM-840A scanning electron microscope (JEOL Ltd, Tokyo, Japan) operated at 20 kV. Photographs were taken at progressively higher magnifications of ×50, ×100, ×500, and ×1000 to view the enamel surface and the adhesive remaining on the enamel surface after debonding. The shear bond strengths of the groups were compared using the one-way ANOVA (analysis of variance) and Tukey post hoc test. The distribution of adhesive remnant index (ARI) score was compared using the Chi-square test. Results: The mean shear bond strength in group I was 10.36 MPa, with a standard deviation of 0.225. The corresponding values in group II and group III were 11.41±0.237 MPa and 11.39±0.201 Mpa, respectively. There was a statistically significant difference between the three groups in the mean shear bond strength values. Conclusion: Sandblasting followed by acid etching provides significantly higher bond strength values compared to acid etching alone, irrespective of the bonding material employed.

Effect of laser welding on the titanium ceramic tensile bond strength

Titanium reacts strongly with elements, mainly oxygen at high temperature. The high temperature of titanium laser welding modifies the surface, and may interfere on the metal-ceramic tensile bond strength. OBJECTIVE: The influence of laser welding on the titanium-ceramic bonding has not yet been established. The purpose of this in vitro study was to analyze the influence of laser welding applied to commercially pure titanium (CpTi) substructure on the bond strength of commercial ceramic. The influence of airborne particle abrasion (Al2O3) conditions was also studied. MATERIAL AND METHODS: Forty CpTi cylindrical rods (3 mm x 60 mm) were cast and divided into 2 groups: with laser welding (L) and without laser welding (WL). Each group was divided in 4 subgroups, according to the size of the particles used in airborne particle abrasion: A - Al2O3 (250 µm); B - Al2O3 (180 µm); C - Al2O3 (110 µm); D - Al2O3 (50 µm). Ceramic rings were fused around the CpTi rods. Specimens were invested and their tensile strength was measured at fracture with a universal testing machine at a crosshead speed of 2.0 mm/min and 200 kgf load cell. Statistical analysis was carried out with analysis of variance and compared using the independent t test (p<0.05). RESULTS: Significant differences were found among all subgroups (p<0.05). The highest and the lowest bond strength means were recorded in subgroups WLC (52.62 MPa) and LD (24.02 MPa), respectively. CONCLUSION: Airborne particle abrasion yielded significantly lower bond strength as the Al2O3 particle size decreased. Mechanical retention decreased in the laser-welded specimens, i.e. the metal-ceramic tensile bond strength was lower.

Microleakage in conservative cavities varying the preparation method and surface treatment

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.

Effectiveness of intraoral suction systems and aspirating tips for evacuation of aluminum oxide particles during use of air-abrasion

Aim: The purpose of this study was to compare the effectiveness of a high-volume evacuation and a conventional intraoral suction system and aspirating tips for capturing aluminum oxide particles during use of an air-abrasion device. Methods: A phantom head was fixed at the dental chair head with secured a metallic device with 5 horizontal shafts, corresponding to operator’s clock related working positions, and one vertical shaft to simulate the operator’s nasal cavity. Petri plates were fixed to the shafts at distances of 20, 40 and 60 cm from the center of the oral cavity of the phantom head to collect the aluminum oxide particles spread over during air abrasion. The dust was aspirated with two types of suction tips used with both suction systems: a conventional saliva ejector and a saliva ejector customized by the adaptation of a 55-mm-diameter funnel. Results: The amount of particles showed that the greatest abrasive particle deposition occurred at a distance of 20 cm from the center of the oral cavity of the phantom head at 9 o’clock operatory position with the conventional saliva ejector attached to high-volume evacuation system. Conclusions: The greatest deposition of aluminum oxide particles occurred at the shortest distance between the operator and the center of the oral cavity, while using the high-volume evacuation system associated to the conventional suction tip.

Bond strength of a composite resin to an adhesive luting cement

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.

Effect of surface treatments on the bond strength of a resin cement to commercially pure titanium

Investigation of the effectiveness of surface treatments that promote a strong bond strength of resin cements to metals can contribute significantly to the longevity of metal-ceramic restorations. This study evaluated the effect of surface treatments on the shear bond strength (SBS) of a resin cement to commercially pure titanium (CP Ti). Ninety cast CP Ti discs were divided into 3 groups (n=30), which received one of the following airborne-particle abrasion conditions: (1) 50 ?m Al2O3 particles; (2) 30 ?m silica-modified Al2O3 particles (Cojet Sand); (3) 110 ?m silica-modified Al2O3 particles (Rocatec). For each airborne-particle abrasion condition, the following post-airborne-particle abrasion treatments were used (n=10): (1) none; (2) adhesive Adper Single Bond 2; (3) silane RelyX Ceramic Primer. RelyX ARC resin cement was bonded to CP Ti surfaces. All specimens were thermally cycled before being tested in shear mode. Failure mode was determined. The best association was Rocatec plus silane. All groups showed 100 percent adhesive failure. There were combinations that promote higher SBS than the protocol recommended by the manufacturer of RelyX ARC.

A investigação da eficácia de tratamentos de superfície que promovem uma forte resistência de união de cimentos resinosos aos metais pode contribuir significantemente para a longevidade das restaurações metalocerâmicas. Este estudo avaliou o efeito de tratamentos de superfície na resistência ao cisalhamento da união de um cimento resinoso ao titânio comercialmente puro (Ti cp). Noventa discos foram fundidos em Ti cp e divididos em 3 grupos (n=30), os quais receberam uma das seguintes condições de jateamento: (1) partículas de Al2O3 de 50 ?m; (2) partículas de Al2O3 modificadas por sílica de 30 ?m (Cojet Sand); (3) partículas de Al2O3 modificadas por sílica de 110 ?m (Rocatec). Para cada condição de jateamento, os seguintes tratamentos pós-jateamento foram utilizados (n=10): (1) nenhum; (2) adesivo Adper Single Bond 2; (3) silano RelyX Ceramic Primer. O cimento resinoso RelyX ARC foi aplicado à superfície do Ti cp. Todos os espécimes foram termociclados antes do ensaio de cisalhamento. O modo de fratura também foi determinado. A melhor associação foi o Rocatec mais silano. Todos os grupos apresentaram 100 por cento de falha adesiva. Houve combinações que promoveram maior resistência ao cisalhamento da união que aquela recomendada pelo fabricante do RelyX ARC.

Effect of surface treatment and storage on the bond strength of different ceramic systems

Aim: The aim of this study was to evaluate the micro shear bond strength of different ceramic systems – IPS Empress 2, Cergogold, In-Ceram Alumina and Cercon - and a dual luting agent. Methods: Twelve specimens of each ceramic were fabricated and divided according different surface treatments: Group 1: No additional treatment was applied to the ceramic surface; Group 2: Ceramics were etched with 9.5% hydrofluoric acid; Group 3: specimens treated with airborne particle abrasion for each ceramic system in accordance with manufacturer’s instructions (n=20). The tests were performed after 24 h or after water storage for 6 months. Data were then assessed statistically using the 3-way ANOVA and the Tukey’s test (P<0.05). Results: For Cergogold and IPS Empress 2 systems, the treatments performed with airborne particle abrasion and hydrofluoric acid showed no significant differences from each other, and both were superior to the groups without treatment. For Cercon and In-Ceram ceramics, no differences were found among the groups (P<0.05). When the surface was treated with hydrofluoric acid, the highest bond strength was found to IPS Empress 2 in the 6-month storage period (P<0.05). Conclusion: Lower bond strength values were only observed with IPS Empress 2 ceramic for the control group in the 6-month storage (P<0.05).

Efeito do tratamento de superfície do titânio comercialmente puro na resistência de união ao cisalhamento / Effect of the surface treatment of commercially pure titanium on the shear bond strength

Objetivo: Avaliar a resistência de união ao cisalhamento entre um material de revestimento estético e um metal submetido a três tratamentos de superfície. Método: Foram confeccionados trinta cilindros metálicos, com 5 mm de comprimento e 4mm de diâmetro cada, obtidos por meio de usinagem de barras de titânio comercialmente puro (Ticp). Os cilindros foram divididos em três grupos conforme o tratamento superficial (n=10): Grupo 1 - jateamento com óxido de alumínio (150 micrometros); Grupo 2 - Sistema Rocatec (3M/ESPE): jateamento com óxido de alumínio (Al2O3) 110 micrometros (Rocatec-pre powder) e com sílica (Rocatec-plus powder) + silano (Rocatec-Sil) e Grupo 3 - Sistema CoJet (3M/ESPE): jateamento com partículas de sílica 30 micrometros + Silano (ESPE Sil). Para confecção dos espécimes, foi aplicado sobre cada base metálica o sistema opaco (Sinfony Opaco, 3M ESPE/EUA) e posteriormente a resina composta para restauração indireta (Sinfony, 3M ESPE/EUA). Os espécimes foram armazenados em água destilada (37 graus Celsius / 24 horas) e submetidos ao ensaio de cisalhamento em máquina de ensaio universal (EMIC, modelo DL- 1000), com célula de carga de 500 Kgf, a uma velocidade constante de 0,5mm/min. Os dados obtidos (MPa) foram submetidos ao teste ANOVA (1 fator) e teste de Tukey (5%). Resultados: Observou-se que o grupo 1 (20,01 - 3,12) diferiu estatisticamente do grupo 2 (27,83 - 3,02) e do grupo 3 (26,91 - 3,65) que, entre si, não diferiram estatisticamente. Conclusão: O tratamento da superfície do Ticp com Rocatec ou CoJet gera maior resistência de união entre o Ticp e a resina Sinfony.

Objective: To assess the shear bond strength of an esthetic coatingmaterial and a metal subjected to three surface treatments. Methods: Thirty metallic cylinders (5 mm high x 4 mm diameter) were fabricated from machining of commercially pure titanium (CPTi) bars. The cylinders were assigned to three groups (n=10), according to the surface treatment: Group 1: 150- micrometrics aluminum oxide particle air abrasion; Group 2 - Rocatec system (3M/ESPE):110- micrometrics aluminum oxide particle air abrasion (Rocatec-pre powder) and silica air abrasion (Rocatec-plus powder) + silane (Rocatec- Sil); and Group 3 - CoJet system (3M/ESPE): 30- micrometrics silica particle air abrasion + silane (ESPE Sil). The specimens were fabricated by applying the opaque system (Sinfony Opaco, 3M/ESPE) followed by indirect composite resin (Sinfony, 3M ESPE/USA). After storage in distilled water at 37 degrees celsius for 24 hours, the specimens were tested in shear strength in a universal testing machine (EMIC, model DL- 1000) with a 500 kgf charge cell at 0.5 mm/min crosshead speed. The obtained data (MPa) were subjected to one-way ANOVA and Tukey's test at 5% significance level. Results: Group 1 (20.01 - 3.12) was statistically different from Group 2 (27.83 -3.02) and Group 3 (26.91 - 3.65). Groups 2 and 3 did not differ significantly from each other. Conclusion: The surface treatment of CPTi with Rocatec or CoJet produced greater bond strength between CPTi and Sinfony composite resin.

Effect of air abrasion on tensile bond strength of a single-bottle adhesive/indirect composite system to enamel

This study evaluated the efficiency of air abrasion alone and associated with phosphoric acid etching on tensile bond strength of a single-bottle adhesive/indirect composite restorative system (Bond 1/Alert) to human enamel. Forty enamel surfaces from extracted human third molars were assigned to 4 groups (n= 10). Mach 4.1 (Kreativ Inc.) air abrasion equipment was used for 20 s. A special system of rod pairs aligned in a specific apparatus was used for tensile strength tests, according to ISO/TR 11405 standard (1994) with some modifications. Bond strength means were: G1 (air abrasion + rinsing + condensable composite resin Alert) = 3.46 ± 0.83 MPa; G2 (air abrasion + rinsing + Bond 1 adhesive system + Alert) = 4.00 ± 1.60 MPa; G3 (air abrasion + rinsing + 37 percent phosphoric acid + rinsing + Bond 1 + Alert) = 20.80 ± 3.95 MPa; and G4 (37 percent phosphoric acid + rinsing + Bond 1 + Alert) = 17.00 ± 2.74 MPa. The statistical analysis by Kruskal-Wallis test revealed that G1 and G2 presented statistically significant difference (p< 0.05) from G3 and G4 (p<0.01) and G1 and G3 did not differ significantly (p> 0.05) from G2 and G4, respectively.

O objetivo deste estudo foi avaliar a eficiência da abrasão a ar associada ou não ao condicionamento com ácido fosfórico na resistência à tração de um sistema restaurador composto por adesivo frasco único/resina composta indireta (Bond 1/Alert) ao esmalte humano. Quarenta superfícies de esmalte de terceiros molares humanos extraídos foram alocadas em 4 grupos (n=10). Foi utilizado o sistema de ar abrasivo Mach 4.1 (Kreativ Inc.) durante 20 s. Um sistema especial de pares de hastes alinhadas em um equipamento específico foi usado para realização dos testes de tração, de acordo com a Norma ISO/TR 11405 (1994) com algumas modificações. Os valores médios obtidos foram: G1 (ar abrasivo + lavagem + resina condensável Alert) = 3,46 ± 0,83 MPa; G2 (ar abrasivo + lavagem + adesivo Bond 1 + Alert) = 4,00 ± 1,60 MPa; G3 (ar abrasivo + lavagem + ácido fosfórico 37 por cento + lavagem + Bond 1 + Alert) = 20,80 ± 3,95 MPa; e G4 (ácido fosfórico 37 por cento + lavagem + Bond 1 + Alert) = 17,00 ± 2,74 MPa. Pela análise estatística (teste Kruskal Wallis), G1 e G2 apresentaram diferença estatisticamente significante em relação a G3 e G4 (p<0,01) e G1 e G3 não diferiram dos grupos G2 e G4, respectivamente (p>0,05).

A influência do jateamento na cimentação de bandas ortodônticas / The effect of sandblasting in band cementation

OBJETIVO: comparar a resistência ao cisalhamento de cinco materiais utilizados na cimentação de bandas ortodônticas: um cimento de ionômero de vidro convencional (Ketac Cem), dois cimentos de ionômero de vidro modificados por resina (3M Multicure Glass Ionomer Cement e Fuji Ortho LC) e duas resinas compostas modificadas por poliácidos (Ultra Band-Lok e Transbond Plus). METODOLOGIA: sobre a superfície de um segmento de banda (6 x 6mm) foi posicionada uma matriz com um orifício de 3mm de diâmetro na qual foi inserido o material para cimentação. Metade da amostra foi jateada com partículas de óxido de alumínio. Os corpos-de-prova foram armazenados a 37ºC por 24 horas em umidade relativa de 100 por cento e submetidos ao teste de cisalhamento a uma velocidade de 0,5mm/min. Utilizou-se ANOVA e o teste de comparações múltiplas de Tukey para comparar os grupos em cada tipo de superfície estudada (com ou sem jateamento), e o teste t Student para amostras pareadas para a comparação dos grupos jateados e não-jateados (p=0,01). RESULTADOS: nos grupos não-jateados, Ultra Band-Lok apresentou uma resistência de união significativamente maior (p<0,01) que a obtida pelos outros materiais, os quais não apresentaram diferença significante entre si. Após o jateamento, as resinas compostas modificadas por poliácidos apresentaram uma resistência de união significativamente maior (p<0,01) que a obtida pelos demais cimentos, sendo que 3M Multicure Glass Ionomer apresentou um valor de união superior (p<0,01) ao obtido pelo Ketac Cem e Fuji Ortho LC. CONCLUSÃO: o jateamento aumentou significativamente (p<0,01) a resistência de união em todos os grupos.

Sistema de abrasão a ar em odontologia: revisão de literatura / Air abrasion system in dentistry: a literature review

Introdução: A preservação da saúde do dente natural de cada paciente é o objetivo básico da odontologia moderna. Na odontopediatria, esse propósito associado à interceptação precoce de problemas na cavidade bucal de forma segura e confortável é a meta a ser alcançada por todo profissional que lida com criança. Para isso, o aprofundamento de conhecimento científicos, sistemas auxiliares de diagnóstico, materiais dentários e novos instrumentos de trabalho têm mudado a visão do cirurgião dentista na maneira de lidar com a cárie. Objetivo: Desse modo esse artigo teve por objetivo por meio de uma revisão de literatura abordar e discutir os fatos que levaram à reintegração no uso clínico de um sistema conservador de preparo cavitário existente desde 1945: a abrasão a ar. Conclusão: Assim pôde-se observar que é muito importante conhecer os objetivos, limitações e indicações do uso desse sistema, bem como, a necessidade de estabelecimento de parâmetros para o seu uso, principalmente noque se refere ao fato da adesividade e microinfiltração do meterial sobre os substratos dentários (dentes decíduos ou permanentes)

Microleakage on class V glass ionomer restorations after cavity preparation with aluminum oxide air abrasion

Este estudo in vitro avaliou a microinfiltração marginal em cavidades classe V preparadas com jato de óxido de alumínio e restauradas com diferentes sistemas ionôméricos. As cavidades foram preparadas nas superfícies vestibular e lingual de 15 terceiros molares hígidos e foram divididas em três grupos com 10 cavidades cada um. Os seguintes materiais foram utilizados: no grupo I, cimento de ionômero de vidro convencional (Ketac Fil) e nos grupo II e III, cimentos de ionômero de vidro modificado por monômeros resinosos (Vitremer e Fuji II LC, respectivamente). O preparo cavitário foi realizado por meio da aplicação do jato de óxido de alumínio (Kreativ Mach 4.1; New Image), com partículas de 27,5 µm. Após a restauração das cavidades, os dentes foram armazenados durante 24 h em água destilada a 37ºC, polidos e então submetido a termociclagem (500 ciclos), imersos em Rodamina B a 0,2% por 24 h, incluídos e seccionados. A análise da microinfiltração marginal foi realizada por meio de um microscópio óptico acoplado a uma câmera e a um computador. As imagens obtidas foram digitalizadas e analisadas utilizando um software que permite uma análise quantitativa padronizada da microinfiltração, em milímetros. As médias (%) obtidas foram: oclusal - I: 25,76 mais ou menos 34,35; II: 20,00 mais ou menos 42,16; III: 28,25 mais ou menos 41,67; cervical I: 23,72 mais ou menos 41,84; II: 44,22 mais ou menos 49,69; III: 39,27 mais ou menos 50,74. Os dados foram submetidos à análise estatística, utilizando os testes de Kruskall-Wallis e Wilcoxon. Não houve diferença estatisticamente significante (p>0.05) entre os materiais testados nem entre as margens oclusal e cervical. Conclui-se que em cavidades classe V preparadas com ar abrasão e restauradas com cimentos de ionômero de vidro convencional e modificados por monômeros resinosos não houve completo vedamento marginal.

Effect of surface treatments of laboratory-fabricated composites on the microtensile bond strength to a luting resin cement

O objetivo deste estudo foi avaliar a influência de diferentes tratamentos de superfície na resistência de união de resinas compostas a um agente de fixação resinoso. Dois compósitos de laboratório, Solidex e Targis, e um compósito convencional, Filtek Z250, foram testados. Quarenta e oito blocos de resina composta (5.0 x 5.0 x 5.0mm) foram confeccionados através da técnica incremental, para cada compósito testado, e foram aleatoriamente divididos em 6 grupos. Os blocos foram submetidos a seis tratamentos de superfície: 1 - Controle, Lixa 600-SiC (C); 2 - Silanização (SI); 3 - Jateamento com Al2O3 50µm por 10 segundos (SA); 4 - Condicionamento com ácido fluorídrico por 60 segundos (HF); 5 - HF + SI; 6 - SA + SI. Blocos submetidos ao mesmo tratamento foram unidos com o agente de fixação resinoso Rely X. Uma carga de 500g foi aplicada por 5 minutos e as amostras foram fotoativadas por 40 segundos. Os blocos unidos foram seccionados em fatias de 0.9mm de espessura perpendicularmente à interface de união (n = 12). Foram realizadas constrições limitando a interface de união a 1mm e as amostras foram levadas para o ensaio de tração. As maiores médias de união foram obtidas para as amostras submetidas à aplicação do silano após o jateamento com Al2O3.

Efeito da ciclagem térmica sobre a resistência de uniäo entre uma cerâmica infiltrada com vidro e um cimento resinoso / Effect of thermocycling on the bond strength of a glass-infiltrated ceramic and a resin luting cement

O objetivo deste estudo foi avaliar o efeito da ciclagem térmica sobre a resistência de adesäo entre a superfície da cerâmica In-Ceram Alumina (VITA) e o cimento resinoso Panavia F (Kuraray). Foram confeccionados quatro blocos de cerâmica In-Ceram com dimensöes de 5x6x6mm. Uma das faces com 6x6mm de cada bloco cerâmico, após condicionamento com o sistema Cojet (ESPE-3M) (jateamento com óxido de alumínio/jateamento com óxido de sílica/ silanizaçäo) foi cimentada com Panavia F, sob peso constante de 750g, a outro bloco idêntico de resina composta Clearfil AP-X (Kuraray). Os blocos de resina foram obtidos por meio de duplicaçäo daqueles de cerâmica a partir de moldes com silicona de adiçäo Express (3M). Os quatro conjuntos formados por cerâmica, cimento e resina foram seccionados em 20 corpos-de-prova com forma de palitos, de modo que a regiäo adesiva apresentasse 1mm2 de área. Dois grupos (n=10) foram constítuidos: G1- estocagem por 7 dias em água deionizada à 36 2ºC; G2- 1500 ciclos entre 5ºC e 55ºC com intervalos de 30 segundos. A seguir, foi realizado o teste de microtraçäo em máquina de ensaio universal (EMIC) com velocidade de 0,5 mm/min. Os resultados mostraram que os valores médios de tensäo de ruptura (MPa) para o grupo G2: (22,815 5,254) näo tiveram diferenças estatisticamente significantes daqueles do grupo G1: (25,628 3,353) (t= 1,427; gl = 18; p-valor = 0,171), ao nível de significância de 5 por cento. A partir destes resultados, entendemos lícito concluir que o efeito da ciclagem térmica näo produziu alteraçöes estatisticamente significantes nos valores da resistência adesiva

Microdentistry - new concepts for the 21st century

This article is a review of the principles and clinical guidelines for the new discipline of Microdentistry. It involves new concepts of early occlusal caries detection using new laser technology and relates to the non G. V. Black nature of the final cavity design. Newly discovered anatomical structures in teeth are discussed and why their conservation is important. New air-abrasion technology is used to cut the tooth, selectively removing damaged tooth structure, rather than the indiscriminate traditional manner of cutting the tooth with a high-speed bur. Microdentistry also relies on the use of adhesive glass-ionomer / composite restorative materials rather than amalgam. Consideration of patient caries risk factors, are also important in case selection and decisions on early intervention. In conclusion, it is hoped that by using early accurate diagnosis and minimal operative treatment, patients will retain their teeth in a cost effective manner