title: Bond strengths of brackets bonded to enamel surfaces conditioned with femtosecond and Er:YAG laser systems.
abstract: The aim of this study was to compare femtosecond and Er:YAG laser systems with regard to enamel demineralization and bracket bond strength. Human-extracted premolars were randomized to three groups (n = 17) depending on the conditioning treatment used for the buccal surfaces: 37 % orthophosphoric acid, Er:YAG laser etching (MSP mode 120 mJ, 10 Hz, 1.2 W), and femtosecond laser etching (0.4 W, 800 nm, 90 fs/pulse, 1 kHz). Metal brackets were bonded with Transbond XT to the conditioned surfaces and light cured for 20 s. The samples were thermocycled (5000 cycles, 5-55 °C) and subjected to shear bond strength (SBS) testing using a universal testing machine. Failure types were analyzed under an optical stereomicroscope and SEM. The adhesive remnant index (ARI) was evaluated to assess residual adhesive on the enamel surface. The results revealed no significant differences in SBS between the Er:YAG laser (7.2 ± 3.3 MPa) and acid etching groups (7.3 ± 2.7 MPa; p < 0.05), whereas a significant difference was observed between the femtosecond laser etching group (3.3 ± 1.2 MPa) and the other two groups (p < 0.01). ARI scores were significantly different among the three groups. The results of our study suggest that laser conditioning with an Er:YAG system results in successful etching, similar to that obtained with acid. The sole use of a femtosecond laser system may not provide an adequate bond strength at the bracket-enamel interface.
authors.affiliation: Faculty of Dentistry, Department of Orthodontics, Sifa University, Mansuroglu Mah. 293/1 Sok No:2 Bayrakli, Izmir, Turkey. cahide@gmail.com.
authors.forename: Cahide
authors.initials: C
authors.lastname: Aglarci
authors.affiliation: Faculty of Dentistry, Department of Prosthodontics, Selcuk University, Konya, Turkey.
authors.forename: Necla
authors.initials: N
authors.lastname: Demir
authors.affiliation: Faculty of Dentistry, Department of Orthodontics, Bezmialem University, Istanbul, Turkey.
authors.forename: Sertac
authors.initials: S
authors.lastname: Aksakalli
authors.affiliation: Faculty of Dentistry, Department of Prosthodontics, Selcuk University, Konya, Turkey.
authors.forename: Erhan
authors.initials: E
authors.lastname: Dilber
authors.affiliation: Faculty of Dentistry, Department of Orthodontics, Mustafa Kemal University, Hatay, Turkey.
authors.forename: Ozlem Akinci
authors.initials: OA
authors.lastname: Sozer
authors.affiliation: Faculty of Science, Department of Physics, Selcuk University, Konya, Turkey.
authors.forename: Hamdi Sukur
authors.initials: HS
authors.lastname: Kilic
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D001641:Bicuspid; D001840:Dental Bonding / Q000379:methods*; D003743:Dental Enamel / Q000737:chemistry; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000008:administration & dosage; D011897:Random Allocation; D019279:Resin Cements; D033081:Shear Strength; D013499:Surface Properties
chemical_list: D010756:Phosphoric Acids; D019279:Resin Cements; C477790:Transbond XT; C030242:phosphoric acid
keywords: Enamel demineralization; Enamel surface conditioning; Er:Yag laser; Femtosecond laser; Shear bond strength