Shear bond strength comparison between two orthodontic adhesives and self-ligating and conventional brackets.
OBJECTIVE
To evaluate and compare the shear bond strengths of two adhesives using two types of brackets: a conventional and a self-ligating bracket system.


METHODS
Sixty extracted human premolars were collected. The premolars were randomly divided into three groups of 20 teeth. All three groups were direct bonded. Groups 1 and 2 used light-cured adhesive and primer (Transbond XT) with a conventional (Orthos) and a self-ligating bracket (Damon 2), respectively. Group 3 used a light-cured primer (Orthosolo) and a light-cured adhesive (Blūgloo) with a self-ligating bracket (Damon 2). The specimens were stored in distilled water at 37 degrees C for 40 +/- 2 hours, after which they were debonded and inspected for Adhesive Remnant Index (ARI) scoring.


RESULTS
The mean shear bond strength was 15.2 MPa for group 1, 23.2 MPa for group 2, and 24.8 MPa for group 3. A one-way analysis of variance and post hoc Tukey test showed significant differences in bond strength (P < .001) between group 1 and groups 2 and 3 but no significant difference (P > .05) between groups 2 and 3. A Weibull analysis demonstrated that all three groups provided sufficient bond strength with over 90% survival rate at normal masticatory and orthodontic force levels. A Kruskal-Wallis test showed no significant difference (P > .05) in ARI scores among all three groups.


CONCLUSIONS
All three groups demonstrated clinically acceptable bond strength. The Damon 2 self-ligating bracket exhibited satisfactory in vitro bond strength with both adhesive systems used.
Northrup
Rodney G
RG
Marquette University, Milwaukee,WI 53201-1881, USA.
Berzins
David W
DW
Bradley
Thomas Gerard
TG
Schuckit
William
W
D000704:Analysis of Variance; D001641:Bicuspid; D001840:Dental Bonding; D003799:Dental Stress Analysis; D006801:Humans; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D019279:Resin Cements; D033081:Shear Strength; D018709:Statistics, Nonparametric; D016019:Survival Analysis
C522883:Blugloo; D019279:Resin Cements; C477790:Transbond XT