Marginal microleakage of resin-modified glass-ionomer and composite resin restorations: effect of using etch-and-rinse and self-etch adhesives.
OBJECTIVE
Previous studies have shown that dental adhesives increase the bond strength of resin-modified glass-ionomer (RMGI) restorative materials to dentin. This in vitro study has evaluated the effect of etch-and-rinse and self-etch bonding systems v/s cavity conditioner, and in comparison to similar composite resin restorations on maintaining the marginal sealing of RMGI restorations.


METHODS
98 rectangular cavities (2.5×3×1.5 mm) were prepared on buccal and palatal aspects of 49 human maxillary premolars, randomly divided into 7 groups (N=14). The cavities in groups 1, 2 and 3 were restored using a composite resin (APX). The cavities in groups 4, 5, 6 and 7 were restored using a resin-modified glass-ionomer (Fuji II LC). Before restoring, adhesive systems (Optibond FL = OFL, three-step etch-and-rinse; One Step Plus = OSP, two-step etch-and-rinse; Clearfil Protect Bond = CPB, two-step self-etch) were used as bonding agents in groups 1-6 as follow: OFL in groups 1 and 4, OSP in groups 2 and 5, and CPB in groups 3 and 6, respectively. The specimens in group 7 were restored with GC cavity conditioner and Fuji II LC. All the specimens were thermo-cycled for 1000 cycles. Microleakage scores were determined using dye penetration method. Statistical analyzes were carried out with Kruskal-Wallis and Mann-Whitney U tests (α=0.05).


RESULTS
There were significant differences in microleakage scores at both enamel and dentinal margins between the study groups (P<0.05). The lowest microleakage scores at enamel and dentin margins of RMGI restorations were observed in group 6.


CONCLUSIONS
Use of two-step self-etch adhesive, prior to restoring cervical cavities with RMGIC, seems to be more efficacious than the conventional cavity conditioner in decreasing marginal microleakage.
Dental Materials Research Center and Department of Operative Dentistry, Isfahan University of Medical Sciences, Isfahan, Iran.
Maryam
M
Khoroushi
Tayebeh Mansouri
TM
Karvandi
Bentolhoda
B
Kamali
Hamid
H
Mazaheri
D000134:Acid Etching, Dental / Q000379:methods; D000180:Acrylic Resins / Q000737:chemistry; D000293:Adolescent; D000328:Adult; D004396:Coloring Agents; D003188:Composite Resins / Q000737:chemistry*; D003737:Dental Cavity Preparation / Q000379:methods; D003738:Dental Cements / Q000737:chemistry*; D003743:Dental Enamel / Q000648:ultrastructure; D003763:Dental Leakage / Q000145:classification*; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000648:ultrastructure; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008689:Methacrylates / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D055815:Young Adult
D000180:Acrylic Resins; C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; C112828:Clearfil AP-X; C503075:Clearfil Protect Bond; D004396:Coloring Agents; D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D008689:Methacrylates; C469607:OptiBond FL; D019279:Resin Cements; D012117:Resins, Synthetic; C006903:carbopol 940