Abstract
Dental sealants are important for prevention of carious lesions, if they have good shear strength. The aim of this study was to evaluate the shear bond strength (SBS) of two sealants to saliva-contaminated and non-contaminated enamel with and without an intermediate adhesive layer underneath the sealant. Ninety flat enamel surfaces from human third molars were randomly assigned to 6 groups (n=15): F (control): Fluroshield(tm) sealant; EWB (control): Embrace(tm) WetBond(tm); SB/F: Single Bond adhesive system + F; SB/EWB, s-SB/F and s-SB/EWB. In the s-SB/F and s-SB/EWB groups, the acid-etched enamel was contaminated with 0.01 mL of fresh human saliva for 20 s. Sealant cylinders were bonded to enamel surface with and without an intermediate adhesive system layer. The shear tests were performed using a universal testing machine (0.5 mm/min). Data were analyzed statistically by Kruskal-Wallis and Mann-Whitney tests (α=0.05). F presented higher mean SBS than EWB in all experimental conditions. The lowest SBS mean was obtained for EWB on contaminated enamel (p<0.05). In conclusion, an adhesive system layer should be used prior to sealant placement, in both dry and saliva-contaminated enamel. F had the best performance in all experimental conditions. EWB sealant showed very low results, but an adhesive layer underneath the sealant increased its SBS even after salivary contamination.
Highlights
Fissure sealants used as preventive treatment on occlusal surfaces act as an effective mechanical barrier against the accumulation and maturation of biofilm [1], especially if it remains intact and bonded to tooth surface [2,3].The ideal time for sealant placement is soon after the eruption of permanent molars [4], as newly erupted teeth are less mineralized and more susceptible to acid attack [5]
Some studies found that BPA could induce changes in various mechanisms and physiological processes, among which early puberty in females and feminization in male at very low levels [12], high-risk breast and prostate cancer [13], calcium influx induction, which leads to release of prolactin [14], development of hyperglycemia, insulin tolerance and diabetes [15], cardiovascular disease [10], abnormal concentration of Y-glutamyl liver enzymes and alkaline phosphatase [16], according to the switching of the β-pancreatic cells [18], dysfunction of thyroid hormone production [18], increase of reactive oxygen species [19], which are implicated in oxidative stress mechanism and over-regulation of cAMP response element binding protein, which inhibits apoptosis [20]
Bisphenol-A free sealant adhesion of FluroshieldTM increased significantly the shear bond strength (SBS) to dry enamel, which did not occur in the presence of salivary contamination
Summary
Fissure sealants used as preventive treatment on occlusal surfaces act as an effective mechanical barrier against the accumulation and maturation of biofilm [1], especially if it remains intact and bonded to tooth surface [2,3].The ideal time for sealant placement is soon after the eruption of permanent molars [4], as newly erupted teeth are less mineralized and more susceptible to acid attack [5]. Sealant placement during this period is challenging because the contact of the tooth with the distal marginal ridge of the gingiva facilitates the contamination of the occlusal surface by moisture or saliva [6], which is the most common cause of sealant failure [2]. The microspores produced by acid etching may be partially occluded after a contamination time as short as one second [7]. This partial obliteration prevents the ideal formation of resin tags, weakening sealant retention [8]. Conventional pit and fissure sealants are extremely sensitive to moisture due to their hydrophobic nature and require a clean, dry and etched enamel surface during placement [9]. Some studies found that BPA could induce changes in various mechanisms and physiological processes, among which early puberty in females and feminization in male at very low levels [12], high-risk breast and prostate cancer [13], calcium influx induction, which leads to release of prolactin [14], development of hyperglycemia, insulin tolerance and diabetes [15], cardiovascular disease [10], abnormal concentration of Y-glutamyl liver enzymes and alkaline phosphatase [16], according to the switching of the β-pancreatic cells [18], dysfunction of thyroid hormone production [18], increase of reactive oxygen species [19], which are implicated in oxidative stress mechanism and over-regulation of cAMP response element binding protein, which inhibits apoptosis [20]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
