Effects of a peripheral enamel bond on the long-term effectiveness of dentin bonding agents exposed to water in vitro.
This study evaluated the effects of water exposure on the in vitro microtensile bond strength (muTBS) of etch-and-rinse and self-etching adhesives to human dentin over a 1-year storage period. Five adhesive systems used were as follows: a one-step self-etching adhesive (One-up Bond F-OB), two two-step self-etching primers (Clearfil SE Bond-SE and Clearfil Protect Bond-CP), and two etch-and-rinse adhesives (Single Bond-SB and Prime&Bond NT-PB). Dentin surfaces were bonded, restored, and assigned to four subgroups, according to the degree of water exposure: 24 h of peripheral water exposure (24 h-PE) (having circumferential enamel); and 1 year of peripheral exposure (1 yr-PE), direct exposure (1 yr-DE) (dentin directly water-exposed), or directly exposed to oil only (no water exposure) (1 yr-DOE). A composite-enamel bond adjacent to the restoration is determined if the water exposure was peripheral or direct. After storage periods, specimens were serially sectioned, trimmed to an hourglass shape with a cross-sectional area of 1 mm(2) at the interface, and tested in tension. Results were analyzed by two-way ANOVA and Tukey test (alpha = 0.05). No difference was found between 24 h-PE and 1 yr-PE for OB, CP, SB, and PB. However, muTBS values significantly dropped after 1 yr-DE for SE, CP, SB, and PB. A decreased muTBS was seen in SE after 1 yr-PE, but no differences existed between 1 yr-PE and 1 yr-DE. Similar or increased muTBS values were noted in 1 yr-DOE for all adhesives. Water-storage for 1 year significantly decreased muTBS for all adhesives. However, except for SE, the presence of a peripheral composite-enamel bond seemed to reduce the degradation rate in resin-dentin interfaces for all materials.
Reis
Andre F
AF
Department of Operative Dentistry, Guarulhos University. R. Nilo Peçanha, No. 81, Guarulhos, SP 07011-040, Brazil.
Giannini
Marcelo
M
Pereira
Patricia N R
PN
D001672:Biocompatible Materials / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods; D003743:Dental Enamel / Q000737:chemistry*; D003804:Dentin / Q000737:chemistry*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry*
D001672:Biocompatible Materials; C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; C438313:Clearfil SE Bond; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D011109:Polymethacrylic Acids; C425843:Prime and Bond NT; D019279:Resin Cements; D014867:Water