Practitioner variability effects on dentin bonding with an acetone-based one-bottle adhesive.
ABSTRACT The objective of this study was to investigate the effect of operator variability on the marginal performance of resin composite restorations bonded with an acetone-base one-bottle adhesive in standardized dentin preparations.
Five general practitioners were recruited for this trial. In the first group, each dentist received six extracted human teeth with dentin preparations (Ø 3.5 mm, 1.5 mm deep), cut in flatground proximal dentin, and original packages of Gluma One Bond adhesive and Charisma resin composite (Heraeus-Kulzer, Werheim, Germany) including instructions for use. For the second group, the operators were orally instructed, emphasizing the importance of the moist technique, before they received another six teeth for restoration with the same materials. Finally, a third group of six preparations was restored in order to evaluate a possible training effect. The restored teeth were stored in a hygrophor prior to removal of excess material and microscopic determination of the maximum marginal gap width (MGW). Statistical analyses were performed with the Kruskal-Wallis and Wilcoxon tests at p < 0.05.
Apart from two samples, preparation margins in the first test group showed gaps between 1 and 12 microns. In the second and third groups, 15 and 16 restorations were gap free, respectively. Significant interoperator variation was found in the first group only. Marginal performance of group 1 restorations was significantly inferior to groups 2 and 3, which were not different (p = 0.79).
Application of the one-bottle adhesive is technique-sensitive and requires meticulous attention to the instructions.
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ABSTRACT: The vascular changes in the subcutaneous connective tissue of rats induced by dentin bonding systems (one step) was studied and compared to those induced by saline solution (negative control) and Furacin (positive control), during the exudative phase of the inflammatory process. Twenty mg/kg of Evan's blue were injected intravenously in the vein of the rats' penises; 0.1 ml of each substance tested was inoculated in the subcutaneous tissue. After a 3 hour period the animals were sacrificed and their skins were excised and punched out with a standard steel 2.5 cm in diameter. The specimens were immediately immersed in 8 ml of formamide and taken to a double boiler for 72 hours at 37 C, to remove the dye. The liquid containing the overflowed dye was filtered, analyzed in the spectrophotometer (620 nm) and classified according to the criteria established by Nagem-Filho, Pereira (1976). After statistical analysis, the irritative potential of the substances was ranked as follows: Furacin (severe) > Single Bond and Bond 1 (moderate - no significant differences between the dentin bonding systems tested) > saline solution (not significant as regards the irritation degree).Pesquisa Odontológica Brasileira 01/2003; 17(2):109-12.
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ABSTRACT: The late Dr. John Gwinnett, one of the most bril- liant and respected members of the dental research and teaching community, often characterized bonding as a chain, a series of links between the restorative material being placed and the tooth tissues.1 And as in a chain, the bond of a restorative material to the tooth sub- strate is only as strong as its weakest link. Dr. Gwinnett inspired a new generation of clinicians and researchers, the author included, to think about adhesion in an entirely new fashion. Insights and inno- vations by contemporaries, friends, and colleagues of Dr. Gwinnett, including Byoung Suh, John Kanca, Charlie Cox, Franklyn Tay, David Pashley, Sumita Mitra, Wayne Barkmeier, and many others, also advanced our knowledge and understanding of adhesion. This eventually led to the development of many of the various adhesive techniques and materials utilized in dentistry today. This paper will focus on some of the current concepts and techniques developed to manage the adhesive interface during the placement of direct poste- rior composite restorations.01/2008;
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ABSTRACT: Objetivos Comparar as forças de adesão (FA) de quatro sistemas adesivos ortodônticos em três períodos de tempo. Métodos Cento e oitenta faces de pré-molares humanos foram distribuídas aleatoriamente em quatro grupos de acordo com os sistemas adesivos testados: Concise™ (G1), Transbond™ XT (G2), Transbond™ Plus Self-Etching Primer (TBS) (G3) and Heliosit®Orthodontic (G4). As FA foram determinadas em três períodos de tempo 15 min; 24 horas e 24 horas seguida de termociclagem (TC). O tipo de fratura foi determinado com o índice de adesivo remanescente (IAR). As resinas compostas, os padrões de condicionamento e as interfaces adesivas foram observadas sob microscopia electrónica de varrimento (MEV). Resultados A ANOVA a 2 fatores não determinou interação entre o tempo ou o tempo e TC no comportamento dos sistemas adesivos (F = 0.372, p = 0.896). O tempo induziu um aumento estatisticamente significativo nas FA (F = 37.447, p < 0.01), enquanto que a termociclagem não influenciou as FA (t = 0.608, p = 0.544). Os sistemas adesivos apresentaram diferenças apenas no período de 15 min (F = 4,75; p = 0,005). O IAR revelou diferenças significativas entre os grupos nos períodos de 24 h e 24h+TC. Os grupos 1, 3 e 4 mostraram diferenças ao longo dos períodos de teste. As observações em MEV revelaram que o TBS produziu um padrão de condicionamento mais irregular e superficial relativamente ao ácido fosfórico. Conclusões Independentemente do sistema adesivo, as FA foram significativamente superiores 24 horas após a colagem dos brackets relativamente aos 15 min. O adesivo autocondicionante pode ser utilizado na colagem de brackets. A termociclagem não afetou as forças de adesão.Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial. 07/2014;