Shear bond strength of orthodontic brackets bonded with different self-etching adhesives.
BACKGROUND
The purpose of this study was to compare the shear bond strength (SBS) of orthodontic brackets bonded with 4 self-etching adhesives.


METHODS
A total of 175 extracted premolars were randomly divided into 5 groups (n = 35). Group I was the control, in which the enamel was etched with 37% phosphoric acid, and stainless steel brackets were bonded with Transbond XT (3M Unitek, Monrovia, Calif). In the remaining 4 groups, the enamel was conditioned with the following self-etching primers and adhesives: group II, Transbond Plus and Transbond XT (3M Unitek); group III, Clearfil Mega Bond FA and Kurasper F (Kuraray Medical, Tokyo, Japan); group IV, Primers A and B, and BeautyOrtho Bond (Shofu, Kyoto, Japan); and group V, AdheSE and Heliosit Orthodontic (Ivoclar Vivadent AG, Liechtenstein). The teeth were stored in distilled water at 37 degrees C for 24 hours and debonded with a universal testing machine. The adhesive remnant index (ARI) including enamel fracture score was also evaluated. Additionally, the conditioned enamel surfaces were observed under a scanning electron microscope.


RESULTS
The SBS values of groups I (19.0 +/- 6.7 MPa) and II (16.6 +/- 7.3 MPa) were significantly higher than those of groups III (11.0 +/- 3.9 MPa), IV (10.1 +/- 3.7 MPa), and V (11.8 +/- 3.5 MPa). Fluoride-releasing adhesives (Kurasper F and BeautyOrtho Bond) showed clinically acceptable SBS values. Significant differences were found in the ARI and enamel fracture scores between groups I and II.


CONCLUSIONS
The 4 self-etching adhesives yielded SBS values higher than the bond strength (5.9 to 7.8 MPa) suggested for routine clinical treatment, indicating that orthodontic brackets can be successfully bonded with any of these self-etching adhesives.
Scougall Vilchis
Rogelio José
RJ
Professor, Department of Orthodontics, School of Dentistry, Dental Research Center (CIEAO), Autonomous University of the State of Mexico (UAEM), Toluca, Mexico. rogelio_scougall@hotmail.com
Yamamoto
Seigo
S
Kitai
Noriyuki
N
Yamamoto
Kohji
K
D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000293:injuries / Q000648:ultrastructure; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
D000180:Acrylic Resins; C489662:AdheSE cement; C519484:Beauty Ortho Bond; C029849:Clearfil Bonding Agent; D003722:Dental Alloys; C472990:Kurasper F; D010756:Phosphoric Acids; D019279:Resin Cements; C429625:Transbond Plus Self-Etching Primer; C477790:Transbond XT; D014867:Water; D013193:Stainless Steel; C047484:heliosit; C030242:phosphoric acid