Effect of different conditioning protocols on the adhesion of a glass ionomer cement to dentin.
OBJECTIVE
The purpose of this study was to assess the effect of different surface treatments on the shear bond strength (SBS) of a resin modified glass ionomer cement (RMGIC) to dentin.


METHODS
Forty human third molar teeth were randomly divided into four groups (n=10). The occlusal enamel was removed to obtain a flat surface of dentin. Each group was treated as follows: Group 1: 10% polyacrylic acid (positive control); Group 2: 37% phosphoric acid followed by 5% sodium hypochlorite (NaOCl); Group 3: 1.1% APF gel; and Group 4: no conditioning (negative control). Fuji II LC glass ionomer was bonded to dentin using a cylindrical mold. Samples were thermocycled and debonded using a shear force with a crosshead speed of 0.5 mm/min. Data were analyzed using one-way analysis of variance (ANOVA) and Tukey tests (a = 0.05).


RESULTS
The mean SBS in Groups 1 through 4 were 11.562+/-3.148, 8.060+/-1.781, 8.830+/-1.554, and 3.074+/-0.784 (MPa), respectively. There were significant differences in the SBS between Group 1 with other groups (P<0.05). There were no statistically significant differences between Groups 2 and 3, but the SBS of both of them were significantly higher than that of Group 4 (P<0.05).


CONCLUSIONS
Although the dentin SBS of Fuji II LC after conditioning with APF and phosphoric acid followed by NaOCl was greater than the unconditioned group (Group 4), polyacrylic acid yielded the best result.


CONCLUSIONS
Proper conditioning of dentin is effective in promoting close adaptation of RMGIC to dentin.
Hajizadeh
Hila
H
Department of Restorative Dentistry, Mashhad Dental School and Dental Research Center, Mashhad University of Medical Sciences, Mashhad, Iran. hajizadehh@mums.ac.ir
Ghavamnasiri
Marjaneh
M
Namazikhah
Mohammad Sadegh
MS
Majidinia
Sara
S
Bagheri
Mahshid
M
D000134:Acid Etching, Dental / Q000379:methods*; D000180:Acrylic Resins / Q000737:chemistry; D000704:Analysis of Variance; D001840:Dental Bonding / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008964:Molar, Third; D010756:Phosphoric Acids / Q000737:chemistry; D012117:Resins, Synthetic / Q000737:chemistry*; D033081:Shear Strength; D016369:Smear Layer; D012973:Sodium Hypochlorite / Q000737:chemistry; D018709:Statistics, Nonparametric; D013499:Surface Properties
D000180:Acrylic Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; D012117:Resins, Synthetic; C006903:carbopol 940; D012973:Sodium Hypochlorite; C030242:phosphoric acid