Shear bond strength of a new high fluoride release glass ionomer adhesive.
OBJECTIVE
To determine the shear bond strength of a new resin glass ionomer adhesive with higher fluoride release properties when bonding orthodontic brackets.


METHODS
Sixty freshly extracted human molars were collected and stored in a solution of 0.1% (weight/volume) thymol. The teeth were cleaned and polished. The teeth were randomly separated into three groups according to the enamel conditioner/etchant and adhesive used. Group I: 20 teeth conditioned with 10% polyacrylic acid and brackets bonded with the new glass ionomer adhesive. Group II: 20 teeth conditioned with 37% phosphoric acid and brackets bonded with the new glass ionomer adhesive. Group III (control): 20 teeth etched with 37% phosphoric acid and brackets bonded with a composite adhesive.


RESULTS
The results of the analysis of variance comparing the three experimental groups (F = 10.294) indicated the presence of significant differences between the three groups (P = .0001). The shear bond strengths were significantly lower in the two groups bonded with the new glass ionomer adhesive whether conditioned with polyacrylic acid ( x = 3.2 +/- 1.8 MPa) or phosphoric acid (x = 2.3 +/- 1.1 MPa), while the mean shear bond strength of the composite adhesive was 5.2 +/- 2.9 MPa.


CONCLUSIONS
Although the increased fluoride release from the new glass ionomer has the potential of decreasing decalcification around orthodontic brackets, the shear bond strength of the material is relatively low.
Bishara
Samir E
SE
College of Dentistry, University of Iowa, Iowa City, Iowa 52242, USA. Samir-bishara@uiowa.edu
Soliman
Manal
M
Laffoon
John F
JF
Warren
John
J
D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000737:chemistry; D002327:Cariostatic Agents / Q000737:chemistry*; D001840:Dental Bonding; D017005:Dental Debonding; D003743:Dental Enamel / Q000648:ultrastructure; D004058:Diffusion; D005459:Fluorides / Q000737:chemistry*; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008963:Molar; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical
D000180:Acrylic Resins; D002327:Cariostatic Agents; D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; D019279:Resin Cements; C477790:Transbond XT; C006903:carbopol 940; C030242:phosphoric acid; D005459:Fluorides