Bond strength of a pit-and-fissure sealant associated to etch-and-rinse and self-etching adhesive systems to saliva-contaminated enamel: individual vs. simultaneous light curing

Abstract

This study evaluated in vitro the shear bond strength (SBS) of a resin-based pit-and-fissure sealant [Fluroshield (F), Dentsply/Caulk] associated with either an etch-and-rinse [Adper Single Bond 2 (SB), 3M/ESPE] or a self-etching adhesive system [Clearfil S3 Bond (S3), Kuraray Co., Ltd.] to saliva-contaminated enamel, comparing two curing protocols: individual light curing of the adhesive system and the sealant or simultaneous curing of both materials. Mesial and distal enamel surfaces from 45 sound third molars were randomly assigned to 6 groups (n=15), according to the bonding technique: I - F was applied to 37% phosphoric acid etched enamel. The other groups were contaminated with fresh human saliva (0.01 mL; 10 s) after acid etching: II - SB and F were light cured separately; III - SB and F were light cured together; IV - S3 and F were light cured separately; V - S3 and F were light cured simultaneously; VI - F was applied to saliva-contaminated, acid-etched enamel without an intermediate bonding agent layer. SBS was tested to failure in a universal testing machine at 0.5 mm/min. Data were analyzed by one-way ANOVA and Fisher's test (alpha=0.05).The debonded specimens were examined with a stereomicroscope to assess the failure modes. Three representative specimens from each group were observed under scanning electron microscopy for a qualitative analysis. Mean SBS in MPa were: I-12.28 (+/-4.29); II-8.57 (+/-3.19); III-7.97 (+/-2.16); IV-12.56 (+/-3.11); V-11.45 (+/-3.77); and VI-7.47 (+/-1.99). In conclusion, individual or simultaneous curing of the intermediate bonding agent layer and the resin sealant did not seem to affect bond strength to saliva-contaminated enamel. S3/F presented significantly higher SBS than the that of the groups treated with SB etch-and-rinse adhesive system and similar SBS to that of the control group, in which the sealant was applied under ideal dry, noncontaminated conditions.

Bond strength and microleakage of self-adhesive and conventional fissure sealants

“…Occurrence of marginal microleakage following the application of CR-based fissure sealant was similar to that obtained with SAR-based fissure sealant -with or without prior PA etching. This similarity was due to the presence of functional monomers in the SARbased fissure sealant used in this investigation, which improved its flowability and penetrability into the capillary-like spaces of etched enamel surface, thereby resulting in improved adhesion and good sealing 40,41) . Ganesh and Shobha 42) reported that the sealing ability of CR-based fissure sealants is better than that of GI-based fissure sealants, as indicated by a lower occurrence of marginal microleakage.…”

Bond Strength of a Bisphenol-A-Free Fissure Sealant With and Without Adhesive Layer under Conditions of Saliva Contamination

“…Studies have shown that the SBS between sealant and enamel surface decreases significantly under conditions of salivary contamination (4). Because of the high enamel reactivity induced by phosphoric acid etching, even minute exposures to saliva, as brief as 1 s, could be sufficient to create a pellicle that partially occludes the enamel pores, causing ultrastructural alterations and preventing formation of the resin tags responsible for mechanical retention (8).…”

“…Fluroshield™ showed higher SBS means when it was associated with adhesive systems without contamination. This is likely due to the great capacity of single-bottle adhesives to flow deeply into capillary-like spaces of the etched enamel surface and produce an optimal resin tag penetration and enhanced adhesion (4).…”

“…Previous studies have reported increased bond strengths after application of an adhesive layer between sealant and contaminated (4,(23)(24)(25) and non-contaminated (23) etched enamel, due to its hydrophilic property (24). A BPAfree fissure sealant moisture-tolerant product has been introduced under the trade name Embrace TM WetBond TM (EWB; Pulpdent Corporation, Watertown, MA, USA), which good marginal adaptation in pits and fissures (22) and reduction of microbial attachment on sealant surface (26).…”

A Comparative Evaluation of the Effect of Bonding Agent on the Tensile Bond Strength of Two Pit and Fissure Sealants Using Invasive and Non-invasive Techniques: An in–vitro Study

“…Feigal [18] reported that adding a bonding agent layer between sealant and saliva contaminated enamel allowed adequate bond strength and retention of resin sealants. However, in a contrasting study, Gomes-Silva [19] concluded that individual or simultaneous curing of the intermediate bonding agent layer and the resin sealant did not seem to affect bond strength to saliva-contaminated enamel. …”