Does the time interval after bleaching influence the adhesion of orthodontic brackets?

OBJECTIVE: To test the null hypothesis that no difference exists between the effects of at-home bleaching and in-office bleaching on shear bond strength (SBS) with bracket bonding at 4 different time intervals after dental bleaching. METHODS: Ninety extracted human premolars were randomly divided into 9 groups (n = 10) according to the bleaching methods used (at-home bleaching and in-office bleaching) and the storage time in artificial saliva (30 min, 1 day, 2 weeks, and 3 weeks before bonding). The control group was stored in artificial saliva for 7 days. Brackets were bonded with the Transbond XT adhesive system, and SBS testing was performed. The adhesive remnant index (ARI) was used to assess the amount of resin remaining on the enamel surfaces after debonding. The SBS data were analyzed by analysis of variance (ANOVA) and the Tukey test. For the ARI, the Kruskal-Wallis test was performed. Significance for all statistical tests was predetermined to be p < 0.05. RESULTS: The SBS of the unbleached group was significantly higher (p < 0.05) than that of the bleached groups (except for the group bonded 30 min after at-home bleaching). CONCLUSIONS: The null hypothesis was not totally rejected. All bleaching groups tested had decreased SBS of the brackets to the enamel, except for the group bonded 30 min after at-home bleaching. The SBS returned to values close to those of the unbleached enamel within 3 weeks following bleaching.

Evaluation of metallic brackets adhesion after the use of bleaching gels with and without amorphous calcium phosphate (ACP): in vitro study.

OBJECTIVE: To evaluate in vitro the effects of tooth whitening using gel with Amorphous Calcium Phosphate (ACP) on the bond strength of metal brackets. METHODS: Thirty-six bovine incisors were sectioned at the crown-root interface, and the crowns were then placed in PVC cylinders. The specimens were divided into 3 groups (n = 12) according to whitening treatment and type of gel used, as follows: G1 (control) - no whitening; G2 - whitening with gel not containing ACP (Whiteness Perfect - FGM), G3 - whitening with gel containing ACP (Nite White ACP - Discus Dental). Groups G2 and G3 were subjected to 14 cycles of whitening followed by an interval of 15 days before the bonding of metal brackets. Shear bond strength testing was performed on a Kratos universal test machine at a speed of 0.5 mm/min. After the mechanical test, the specimens were assessed to determine the adhesive remnant index (ARI). The results were subjected to ANOVA, Tukey's test and Kruskal-Wallis test (5%). RESULTS: Significant differences were noted between the groups. Control group (G1 - 11.10 MPa) showed a statistically higher shear bond strength than the groups that underwent whitening (G2 - 5.40 Mpa, G3 - 3.73 MPa), which did not differ from each other. There were no significant differences between the groups in terms of ARI. CONCLUSIONS: Tooth whitening reduces the bond strength of metal brackets, whereas the presence of ACP in the whitening gel has no bearing on the results.

Evaluation of metallic brackets adhesion after the use of bleaching gels with and without amorphous calcium phosphate (ACP): in vitro study

OBJECTIVE: To evaluate in vitro the effects of tooth whitening using gel with Amorphous Calcium Phosphate (ACP) on the bond strength of metal brackets. METHODS: Thirty-six bovine incisors were sectioned at the crown-root interface, and the crowns were then placed in PVC cylinders. The specimens were divided into 3 groups (n = 12) according to whitening treatment and type of gel used, as follows: G1 (control) = no whitening; G2 = whitening with gel not containing ACP (Whiteness Perfect - FGM), G3 = whitening with gel containing ACP (Nite White ACP - Discus Dental). Groups G2 and G3 were subjected to 14 cycles of whitening followed by an interval of 15 days before the bonding of metal brackets. Shear bond strength testing was performed on a Kratos universal test machine at a speed of 0.5 mm/min. After the mechanical test, the specimens were assessed to determine the adhesive remnant index (ARI). The results were subjected to ANOVA, Tukey's test and Kruskal-Wallis test (5%). RESULTS: Significant differences were noted between the groups. Control group (G1 = 11.10 MPa) showed a statistically higher shear bond strength than the groups that underwent whitening (G2 = 5.40 Mpa, G3 = 3.73 MPa), which did not differ from each other. There were no significant differences between the groups in terms of ARI. CONCLUSION: Tooth whitening reduces the bond strength of metal brackets, whereas the presence of ACP in the whitening gel has no bearing on the results.

OBJETIVO: avaliar, in vitro, a influência do clareamento dentário com gel contendo fosfato de cálcio amorfo (ACP) na resistência da união adesiva de braquetes metálicos. MÉTODOS: trinta e seis dentes incisivos bovinos foram seccionados no limite coronorradicular e tiveram suas coroas incluídas em cilindros de PVC. Os corpos de prova foram divididos em três grupos (n = 12), de acordo com a realização do tratamento clareador e tipo de gel utilizado, sendo: G1 (controle) - sem clareamento; G2 - clareamento com gel sem ACP (Whiteness Perfect, FGM); G3 - clareamento com gel contendo ACP (Nite White ACP, Discus Dental). Os grupos G2 e G3 foram submetidos a 14 ciclos de clareamento, seguidos de intervalo de espera de 15 dias para a fixação adesiva dos braquetes metálicos. O ensaio mecânico de cisalhamento foi realizado em máquina universal Kratos, com velocidade de 0,5mm/min. Após o teste mecânico, os corpos de prova foram avaliados quanto ao índice de remanescente adesivo (ARI). Os resultados foram submetidos à ANOVA, ao teste de Tukey e ao de Kruskall-Wallis (α = 5%). RESULTADOS: diferenças significativas foram observadas entre os grupos testados. O grupo controle G1 (11,1MPa) mostrou uma resistência ao cisalhamento estatisticamente superior aos grupos submetidos ao clareamento (G2 = 5,40MPa; G3 = 3,73MPa), os quais não diferiram entre si. Não se observou diferença significativa para o ARI entre os grupos estudados. CONCLUSÃO: o clareamento dentário reduz a resistência da união adesiva de braquetes metálicos, enquanto a presença de ACP no gel clareador não influencia os resultados encontrados.

Low shrinkage composite resins: influence on sealing ability in unfavorable C-factor cavities.

The present investigation observed the sealing ability of low shrinkage composite resins in large and deep cavities, placed and photocured in one increment. Large, deep cavities (5.0 mm diameter and 2.5 mm deep) surrounded by enamel were prepared in bovine teeth, which were then divided into five groups. Groups 1, 2, 3 and 4: acid conditioning + Adper Single Bond (3M/ESPE, St Paul, MN, USA) and restoration with Aelite LS Posterior (BISCO Inc. Schaumburg, IL, USA) (G1); Filtek Z-350 (3M/ESPE,St Paul, MN, USA) (G2); Filtek Z-350 Flow (3M/ESPE, St Paul, MN, USA) (G3); Premisa (KERR Corporation, Orange, CA, USA) (G4). Group 5: Silorane Adhesive system (3M/ESPE, St Paul, MN, USA) + restoration with Filtek Low Shrinkage Posterior P90 (3M/ESPE, St Paul, MN, USA). After polymerization, the teeth were immersed in 0.5% basic fuchsine solution and immediately washed. Using the Imagetool Software, the extent of dye along the margins was calculated as a percentage of total perimeter. The restorations were then transversally sectioned and the depth of dye penetration was calculated in mm, using the same software. Kruskal-Wallis analysis for all groups showed no statistical differences for extent (p = 0.54) or depth (p = 0.8364) of dye penetration. According to this methodology, the so-called low shrinkage composite resins had the same sealing ability compared to regular and flowable nanocomposite materials.

Low shrinkage composite resins: influence on sealing ability in unfavorable C-factor cavities

The present investigation observed the sealing ability of low shrinkage composite resins in large and deep cavities, placed and photocured in one increment. Large, deep cavities (5.0 mm diameter and 2.5 mm deep) surrounded by enamel were prepared in bovine teeth, which were then divided into five groups. Groups 1, 2, 3 and 4: acid conditioning + Adper Single Bond (3M/ESPE, St Paul, MN, USA) and restoration with Aelite LS Posterior (BISCO Inc. Schaumburg, IL, USA) (G1); Filtek Z-350 (3M/ESPE,St Paul, MN, USA) (G2); Filtek Z-350 Flow (3M/ESPE, St Paul, MN, USA) (G3); Premisa (KERR Corporation, Orange, CA, USA) (G4). Group 5: Silorane Adhesive system (3M/ESPE, St Paul, MN, USA) + restoration with Filtek Low Shrinkage Posterior P90 (3M/ESPE, St Paul, MN, USA). After polymerization, the teeth were immersed in 0.5 percent basic fuchsine solution and immediately washed. Using the Imagetool Software, the extent of dye along the margins was calculated as a percentage of total perimeter. The restorations were then transversally sectioned and the depth of dye penetration was calculated in mm, using the same software. Kruskal-Wallis analysis for all groups showed no statistical differences for extent (p = 0.54) or depth (p = 0.8364) of dye penetration. According to this methodology, the so-called low shrinkage composite resins had the same sealing ability compared to regular and flowable nanocomposite materials.

Clinical evaluation of postoperative sensitivity using self-etching adhesives containing glutaraldehyde.

The present clinical study aimed to assess the postoperative sensitivity (POS) after 48 hours and seven days in occlusal restorations bonded with three different adhesive systems, two of them containing glutaraldehyde. The restorative procedures were performed using the three-step etch-and-rinse Adper SBMP-Plus adhesive (SBMP), the two-step etch-and-rinse Gluma Comfort One Bond + Desensitizer adhesive (GC+D) and the all-in-one self-etching/priming I Bond (IB) adhesive, which also has glutaraldehyde in its formula. All cavities were restored with Filtek Supreme nanoparticle composite resin. After 48 hours and seven days the patients were recalled and the postoperative sensitivity evaluated. The data analyzed by non-parametric Friedman test showed no significant differences in POS among the three tested groups after 48 hours and seven days.

Clinical evaluation of postoperative sensitivity using self-etching adhesives containing glutaraldehyde

The present clinical study aimed to assess the postoperative sensitivity (POS) after 48 hours and seven days in occlusal restorations bonded with three different adhesive systems, two of them containing glutaraldehyde. The restorative procedures were performed using the three-step etch-and-rinse Adper SBMP-Plus adhesive (SBMP), the two-step etch-and-rinse Gluma Comfort One Bond + Desensitizer adhesive (GC+D) and the all-in-one self-etching/priming I Bond (IB) adhesive, which also has glutaraldehyde in its formula. All cavities were restored with Filtek Supreme nanoparticle composite resin. After 48 hours and seven days the patients were recalled and the postoperative sensitivity evaluated. The data analyzed by non-parametric Friedman test showed no significant differences in POS among the three tested groups after 48 hours and seven days.

Análise da adesão de braquetes metálicos fixados por meio do sistema adesivo autocondicionante sob condições específicas / Analysis of adhesion of steel brackets bond of self etching adhesive system under specific conditions

Este estudo laboratorial avaliou a adesão de bráquetes ortodônticos metálicos colados sob condições específicas (força aplicada e armazenamento em meio úmido), por meio de teste de resistência adesiva (cisalhamento) e Índice de Remanescente de Adesivo (IRA - Artun e Bergnland), do sistema adesivo autocondicionante -Transbond Plus Self Etching Primer-3M. Utilizou-se 48 incisivos bovinos em quatro condições com 12 espécimes: Condição 1: (controle) teste após colagem; Condição 2: colagem e armazenamento por 2 dias em água destilada e testes; Condição 3: colagem, armazenamento por 90 dias em água destilada e testes; Condição 4: colagem, armazenamento por 90 dias em água destilada sob força (80g com mola de niquel titâneo) aplicada no corpo de prova e testes. A resistência adesiva foi testada na máquina de ensaio universal Kratos à velocidade de 0,5 mm/min e carga 50kg/f e o IRA avaliado em lupa estereoscópica. Os dados foram submetidos à ANOVA dois fatores e ao teste de Tukey (5%) para a resistência de adesão e Kruskall-Wallis para o IRA. Observou-se que houve uma diferença estatística significativa (p<0,0001) dos resultados da condição 1 (teste imediato) em relação as demais condições (2 dia; 90 dias e 90 dias com carga aplicada). No IRA o teste estatístico não apresentou diferenças entre as 4 condições do estudo (p=0.267). A condição especifica de aplicação de força e armazenamento em meio úmido por tempo prolongado dos espécimes foi fator de diferença na resistência adesiva do adesivo autocondicionante. Nenhuma condição específica teve influência significativa sobre o valor do IRA.

This study assessed the adhesion of metallic orthodontic brackets bonded under specific conditions (force applied and storage in humid conditions), through a test of bond strength (shear) and the Adhesive Remnant Index (ARI - Artun and Bergnland) System etching adhesive Transbond Plus Self-Etching Primer, 3M. Was used 48 bovine incisors with 12 specimens in four conditions: Condition 1: (control) test after bonding; Condition 2: bonding and stored for 2 days in distilled water and testing; Condition 3: bonding, storage for 90 days in distilled water and testing; 4 Condition: bonding, storage for 90 days in distilled water under power (80g nickel titanium spring) applied on the specimen and testing. The bond strength was tested in Kratos universal testing machine at a speed of 0.5 mm/min and load 50kg/f. IRA evaluated in a stereomicroscope. The data were subjected to two-factor ANOVA and Tukey test (5%) for the bond strength and Kruskal-Wallis test for the IRA. It was observed that there was a statistically significant difference (p <0.0001) the results of condition 1 (immediate test) compared with other conditions (2 days, 90 days and 90 days with applied load). In the IRA the statistical test showed no differences between the four study conditions (p = 0267). The condition specifies the application of power and storage in humid conditions for prolonged periods of the specimens was a factor of difference in bond strength of adhesive autocondicionate. No specific condition had significant influence on the value of the IRA.

Análise do teor de fluoreto em àguas minerais comercializadas em Belém do Pará / Fluoride content of still bottled water in Belém of Pará

Objetivo: analisar a concentração do íon fluoreto em amostras de água mineral comercializadas na cidade de Belém do Pará, 2009 Método: transversal analítico. Colhidas 07 amostras das marcas comerciais, (Terra Alta, Belágua, Y Yamada, Indaiá, Schincariol, Nossa água, Prata) e realizada análise quantitativa de flúor (mg/l), utilizando o espectrofotômetro, Metrolab 330. As amostras estavam com a temperatura ambiente de 28ºC. Resultados: Indaiá =0,0ppm; Terra Alta=0,1ppm ; Belágua=0,02ppm ; Y Yamada=0,02ppm; Schincariol=0,04ppm; Nossa água =0,04 ppm ; Prata=0,26ppm. Considerações finais: os resultados mostraram uma insuficiência de fluoreto de sódio nas águas minerais, tanto para prevenção, quanto para a ocorrência de fluorose dentária

Objective: the objective of the present study was to determine the fluoride concentrations of 07 commercial marks mineral water (mg/l) in Belém of Pará , 2009 Methods: analytic transversal study . Espectrofotometro, Metrolab 33 0 , was utilized to determinate thefluoride concentration of 7 samples of mineral commercial water. The samples were with the ambient temperature of 28ºC. Results: Indaiá =0,0ppm, Terra Alta=0,1ppm , Belágua=0,02ppm , Y Yamada=0,02ppm , Schicariol=0,04ppm, Nossa água =0,04 ppm , Prata= 0,26ppm Conclusion: the results had in such a way shown an insufficiencies of sodium fluoride in mineral waters for prevention how much for the dental occurrence of fluorose.