title: Shear bond strength of tooth-colored indirect restorations bonded to coronal and cervical enamel.
abstract: This study evaluated the shear bond strength of resin inlays bonded with resin cement to cervical and mid-coronal enamel. Two regions of enamel, cervical and mid-coronal, were chosen from the buccal surface of extracted molars. Composite "inlays" (Estenia, Kuraray Medical Inc) were fabricated indirectly and cemented with a dual-cured resin cement (Panavia Fluoro Cement II, Kuraray Medical Inc). The resin cement was cured with or without light irradiation for 30 seconds. After 24-hours or one-week's storage in 37 degrees C water, the bonded inlays were subjected to a microshear bond test, whereby a shear force was applied to the inlays at a crosshead speed of 1 mm/minute. The data were statistically analyzed using ANOVA and Fisher's PLSD test, with significance defined as p<0.05. Observations using confocal laser scanning microscopy were also performed after debonding the specimens. The light-cure method showed significantly higher bond strengths to both enamel regions compared with self-cure, especially at 24 hours (p<0.05). However, bond strength of the self-cured resin cement significantly improved after one week's storage (p<0.05; cervical enamel: p=0.022, midcoronal enamel: p=0.0024). The cervical enamel showed significantly lower bonding than midcoronal enamel (p<0.05), except for the self-cured specimens at 24 hours. Light curing of resin cement is a better choice than self-curing for luting of indirect restorations. The bond strength of indirect restorations to cervical enamel was lower than mid-coronal enamel.
authors.affiliation: Cariology and Operative Dentistry, Department of Restorative Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan. shimada.ope@tmd.ac.jp
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shimada
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Tomimatsu
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Suzuki
authors.forename: M Akhtar
authors.initials: MA
authors.lastname: Uzzaman
authors.forename: Michael F
authors.initials: MF
authors.lastname: Burrow
authors.forename: Junji
authors.initials: J
authors.lastname: Tagami
mesh_terms: D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D006801:Humans; D007284:Inlays; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000528:radiation effects; D018613:Microscopy, Confocal; D011140:Polyurethanes / Q000737:chemistry / Q000528:radiation effects; D019279:Resin Cements / Q000737:chemistry / Q000528:radiation effects; D033081:Shear Strength; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D019237:Tooth Cervix / Q000648:ultrastructure*; D019228:Tooth Crown / Q000648:ultrastructure*
chemical_list: D003188:Composite Resins; D008689:Methacrylates; C438843:Panavia-Fluoro; D011140:Polyurethanes; D019279:Resin Cements; C091839:urethanetrimethacrylate