title: Light-curing efficiency of dental adhesives by gallium nitride violet-laser diode determined in terms of ultimate micro-tensile strength.
abstract: The purpose of this study was to evaluate whether violet-laser diode (VLD) can be used as light-curing source. The ultimate (micro-)tensile strength (μTS) of three adhesives was determined when cured by VLD in comparison with curing by two different types of commercial LED light-curing units. One VLD (VLM 500) and two LED units (Curenos and G-Light Prima) were used to cure the adhesive resin of the two-step self-etch adhesives Clearfil SE Bond, Tokuso Mac Bond II, and FL-Bond II. A 0.6-mm thick acrylic mould was filled with adhesive resin and cured for 60 s. After 24-h water storage, specimens were trimmed into an hourglass shape with a width of 1.2 mm at the narrowest part, after which the μTS was determined (n=10). In addition, the light transmittance of each adhesive was characterized using a UV-vis-NIR spectrometer. No significant difference in curing efficiency between VLD and LED were observed for both Tokuso Mac Bond II and FL-Bond II (p>0.05). For Clearfil SE Bond, the μTS of VLD-cured specimens was higher than that of the specimens cured by the LED Curenos unit (p<0.05). Spectrometry revealed that this marked difference must be attributed to a different light transmittance of Clearfil SE Bond for visible blue light versus for the lower area of UV and visible violet light. In conclusion, A GaN-based violet laser diode can be used as light-curing source to initiate polymerization of dental resins.
authors.affiliation: Division of General Dentistry, Tokyo Dental College Chiba Hospital, Japan. kameyama@tdc.ac.jp
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kameyama
authors.forename: Junji
authors.initials: J
authors.lastname: Kato
authors.forename: Jan
authors.initials: J
authors.lastname: De Munck
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Hatayama
authors.forename: Akiko
authors.initials: A
authors.lastname: Haruyama
authors.forename: Masao
authors.initials: M
authors.lastname: Yoshinari
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Takase
authors.forename: Bart
authors.initials: B
authors.lastname: Van Meerbeek
authors.forename: Masatake
authors.initials: M
authors.lastname: Tsunoda
mesh_terms: D055117:Curing Lights, Dental; D003738:Dental Cements / Q000528:radiation effects*; D004526:Efficiency; D005708:Gallium / Q000737:chemistry*; D054023:Lasers, Semiconductor; D008832:Microchemistry; D008954:Models, Biological; D013057:Spectrum Analysis; D013718:Tensile Strength / Q000528:radiation effects*
chemical_list: D003738:Dental Cements; C473348:gallium nitride; D005708:Gallium