EUROPEAN JOURNAL OF PAEDIATRIC DENTISTRY • 4/2005 185 Sealing ability and bond strength of four contemporary adhesives to enamel and to dentine R. ATASH, A. VANDEN ABBEELE ABSTRACT . Aim To compare the shear bond strength and microleakage of four adhesive systems to the enamel and dentine of primary bovine teeth. Methods 120 bovine primary mandibular incisors were collected and stored in an aqueous 1% chloramine solution at room temperature for no longer than 3 months after extraction (80 for shear bond testing and 40 for microleakage evaluation). The adhesives tested were Clearfil ® SE bond (SE), Adper Prompt L Pop ® (LP), Xeno III ® (XE), and Prime & Bond NT ® (PB). For shear bond strength testing the specimens were wet ground to 600 grit SiC paper to expose a flat enamel or dentine surface. After bonding and restoration with Dyract AP ® (DAP), the teeth were subjected to shear stress using a universal testing machine. For microleakage evaluation, facial class V cavities were prepared half in enamel and half in cementum. All cavities were restored with DAP. After thermocycling and immersion in 2% methylene blue, the dye penetration was evaluated under a stereomicroscope. Statistics All data were analysed by Chi-square tests or Fisher’s tests when adapted in order to determine the significant differences between groups. Results were considered as significant for p < 0.05. Results were analysed with an ANOVA test and a Bonferroni’s multiple comparison. The level of significance was p < 0.05. Results Shear bond strength values (MPa,) ranged from: on enamel 11.06 to 5.34, in decreasing order SE, LP, XE and PB and on dentine 10.47 to 4.74, in decreasing order SE, XE, LP and PB. Differences in bond strengths between the four systems on enamel and dentine were all statistically significant, excepted for XE vs LP (shear bond at dentine). No significant differences were recorded in the microleakage degree between the four adhesive systems on enamel and on dentine (p >0.0.5). Conclusions The highest shear bond strength was achieved by Clearfil SE bond and the lowest by Prime & Bond NT. There was no significant difference concerning the sealing ability of the four adhesive systems. KEYWORDS: Microleakage, Shear bond, Self-etching adhesive, Compomers, Primary bovine teeth. Department of Adult and Paediatric Operative Dentistry, Faculty of Medicine, Free University of Brussels, Brussels, Belgium atash_ramin@yahoo.fr colour matching [Somphone et al., 2002]. Moreover the physical properties of compomers are similar to those of resin-based composites [Attin, 1996]. Compomers contain fluoroaluminosilicate glass and polymerisable acidified monomers and have been reported to release fluoride after water absorption from the oral environment [El Kalla and Garcia- Godoy, 1999]. Because of their high resin content, compomers can be bonded to dentine with dentine bonding agent similar to those used for bonding resin composites to dentine, even though specific bonding systems were developed by some manufacturers. However, bond strengths of bonding systems specific to compomers have been reported to be inferior to those of dentine bonding systems for resin-based composite [Wilder et al., 1998] at least on permanent teeth. A contemporary approach to dentine and enamel adhesion involves the use of acidic or self-etching Introduction The durability of restorative materials is usually measured using dental amalgam as a standard and, subsequently, composite resins and especially conventional glass ionomer cements are reported with a higher failure rate [Kilpatrick, 1993]; therefore the search for improvements of the mechanical properties of glass ionomer cements led to the incorporation of light cured resin components resulting in the introduction of compomers. The latter, or polyacid- modified resin based composite resins (CR), were developed in the 1990’s and combine the technology of glass-ionomer cements (GIC) and resin-based composites with adequate handling characteristics and art. Atash 28-11-2005 12:15 Pagina 185