title: Optimal Er:YAG laser irradiation parameters for debridement of microstructured fixture surfaces of titanium dental implants.
abstract: Er:YAG laser (ErL) irradiation has been reported to be effective for treating peri-implant disease. The present study seeks to evaluate morphological and elemental changes induced on microstructured surfaces of dental endosseous implants by high-pulse-repetition-rate ErL irradiation and to determine the optimal irradiation conditions for debriding contaminated microstructured surfaces. In experiment 1, dual acid-etched microstructured implants were irradiated by ErL (pulse energy, 30-50 mJ/pulse; repetition rate, 30 Hz) with and without water spray and for used and unused contact tips. Experiment 2 compared the ErL treatment with conventional mechanical treatments (metal/plastic curettes and ultrasonic scalers). In experiment 3, five commercially available microstructures were irradiated by ErL light (pulse energy, 30-50 mJ/pulse; pulse repetition rate, 30 Hz) while spraying water. In experiment 4, contaminated microstructured surfaces of three failed implants were debrided by ErL irradiation. After the experiments, all treated surfaces were assessed by stereomicroscopy, scanning electron microscopy (SEM), and/or energy-dispersive X-ray spectroscopy (EDS). The stereomicroscopy, SEM, and EDS results demonstrate that, unlike mechanical treatments, ErL irradiation at 30 mJ/pulse and 30 Hz with water spray induced no color or morphological changes to the microstructures except for the anodized implant surface, which was easily damaged. The optimized irradiation parameters effectively removed calcified deposits from contaminated titanium microstructures without causing substantial thermal damage. ErL irradiation at pulse energies below 30 mJ/pulse (10.6 J/cm(2)/pulse) and 30 Hz with water spray in near-contact mode seems to cause no damage and to be effective for debriding microstructured surfaces (except for anodized microstructures).
authors.affiliation: Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. taniperi@tmd.ac.jp.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Taniguchi
authors.forename: Akira
authors.initials: A
authors.lastname: Aoki
authors.forename: Koji
authors.initials: K
authors.lastname: Mizutani
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Takeuchi
authors.forename: Shizuko
authors.initials: S
authors.lastname: Ichinose
authors.forename: Aristeo Atsushi
authors.initials: AA
authors.lastname: Takasaki
authors.forename: Frank
authors.initials: F
authors.lastname: Schwarz
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Izumi
mesh_terms: D000134:Acid Etching, Dental; D003646:Debridement / Q000379:methods*; D015921:Dental Implants; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D014025:Titanium
chemical_list: D015921:Dental Implants; D014025:Titanium