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: Objectives: The objective of this study was to measure the biocompatibility of three-types of tissue-engineering scaffolds using ex vivo cultures of human dental pulp (DP) in tooth slices. Methods: Following IRB approval and patient consent, freshly-extracted teeth were collected immediately following extraction for routine dental treatment reasons. The teeth (n=15) were cut into 1mm thick longitudinal tooth slices (n=45) using a diamond-blade rotary saw (Buehler, Lake Bluff, IL) and placed in submerged in Dulbecco's Minimal Essential Media containing 10% fetal calf serum and antibiotics, maintained at 37oC in a 5% CO2 atmosphere for 7, 14, and 21 days. Neutral red dye (0.0016%) was added to the culture media to stain metabolically active cells. During culture, three-types of tissue-engineering scaffolds; polymer, collagen, and calcium phosphate (BD Biosciences, Franklin Lakes, NJ) were placed in direct contact with the DP of the tooth slices. The specimens were fixed in formalin, dehydrated and processed for histology. The numbers of DP cells were counted per light microscope field (x200 magnification) for the biocompatibility assessment. Data was analyzed by analysis of variance (ANOVA) statistical tests (P values) at a significance of 95%. Results: The greatest numbers of dental pulp DP cells were observed in the collagen and polymer scaffolds, compared to the calcium phosphate scaffolds (P<0.05) especially over longer time periods (P<0.05). Conclusions: Human tooth slice organ cultures have the potential to screen the biocompatibility of human dental pulp to tissue engineering scaffolds before they are used for dental pulp regenerative therapies. Research supported by NIH/NIDCR grant DE015573.AADR Annual Meeting 2010; 03/2010
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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.07/2014; DOI:10.1016/j.rpemd.2014.08.003
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ABSTRACT: Resin bonding to dentin is less durable than bonding to enamel. Bonding to dentin had been a great challenge till date. Though the current dental adhesive systems have tremendously improved the complex dentin bonding, there are still challenges that need to be addressed. Improper handling of the dental adhesive systems is one of the several reasons for the decrease in durability of resin-dentin bonds over time. Improper handling includes inappropriate storage and inaccurate method(s) of application. Solvents incorporated in the dental adhesive systems are known to dissolve methacrylate monomer/co-monomer blends and the initiator/co-initiator systems. These solvents are volatile and they play several important roles in achieving successful and durable bond to dentin. Lack of knowledge about the role of solvents used in dental adhesives could be one of the reasons for improper handling of the dental adhesive systems. This overview discusses the solvent aspects of current dental adhesive systems and their applications in bonding. The overview consists of published literature retrieved from “Pubmed”, by using specific key words “solvents”, “resin adhesives”, “dentin”, “bonding”. The relevant literature was retrieved after screening the titles and the abstracts. Further relevant articles that were included for the overview were retrieved from the reference lists of the initially retrieved articles. The literature seems to indicate that solvent type, solvent content and other factors, like storage of the adhesives and methods of application play a major role in dentin bonding. The knowledge acquired on the solvents and their roles in dentin bonding would enable the users of the dental adhesives to handle them appropriately and consequently achieve strong and durable resin-dentin bonds.International Journal of Adhesion and Adhesives 01/2014; 57. DOI:10.1016/j.ijadhadh.2014.09.007 · 2.22 Impact Factor