title: Bonding with self-etching primers--pumice or pre-etch? An in vitro study.
abstract: The purpose of this study was to compare the shear bond strengths (SBSs) of orthodontic brackets bonded with self-etching primer (SEP) using different enamel surface preparations. A two-by-two factorial study design was used. Sixty human premolars were harvested, cleaned, and randomly assigned to four groups (n = 15 per group). Teeth were bathed in saliva for 48 hours to form a pellicle. Treatments were assigned as follows: group 1 was pumiced for 10 seconds and pre-etched for 5 seconds with 37 per cent phosphoric acid before bonding with SEP (Transbond Plus). Group 2 was pumiced for 10 seconds before bonding. Group 3 was pre-etched for 5 seconds before bonding. Group 4 had no mechanical or chemical preparation before bonding. All teeth were stored in distilled water for 24 hours at 37°C before debonding. The SBS values and adhesive remnant index (ARI) score were recorded. The SBS values (± 1 SD) for groups 1-4 were 22.9 ± 6.6, 16.1 ± 7.3, 36.2 ± 8.2, and 13.1 ± 10.1 MPa, respectively. Two-way analysis of variance and subsequent contrasts showed statistically significant differences among treatment groups. ARI scores indicated the majority of adhesive remained on the bracket for all four groups. Pre-etching the bonding surface for 5 seconds with 37 per cent phosphoric acid, instead of pumicing, when using SEPs to bond orthodontic brackets, resulted in greater SBSs.
authors.affiliation: Department of Developmental Sciences, Marquette University School of Dentistry, Milwaukee, WI 53201-1881, USA.
authors.forename: Ian
authors.initials: I
authors.lastname: Fitzgerald
authors.forename: Gerard T
authors.initials: GT
authors.lastname: Bradley
authors.forename: Jose A
authors.initials: JA
authors.lastname: Bosio
authors.forename: Arthur F
authors.initials: AF
authors.lastname: Hefti
authors.forename: David W
authors.initials: DW
authors.lastname: Berzins
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000268:Adhesiveness; D003722:Dental Alloys / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure; D044622:Dental Pellicle / Q000648:ultrastructure; D003777:Dental Prophylaxis / Q000379:methods*; D003799:Dental Stress Analysis / Q000295:instrumentation; D055119:Elastic Modulus; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D017640:Silicates / Q000737:chemistry*; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D003722:Dental Alloys; D010756:Phosphoric Acids; D019279:Resin Cements; D017640:Silicates; C429625:Transbond Plus Self-Etching Primer; D014867:Water; D013193:Stainless Steel; C030242:phosphoric acid; C005144:pumice