Dentine Laser Welding: A New Help for Fractured

An important surgical goal is to provide a first intention wound healing without trauma 11 produced by sutures and for this aim in the past several methods have been tested. 12 The aim of this preliminary ex vivo study is to demonstrate the capacity of a 1070 nm pulsed fiber 13 laser to treat the dental fractures by dentine melting with the apposition of hydroxyapatite 14 nanoparticles as filler. 15 Only the specimens of the group b showed a real process of welding of the two parts, while 16 specimens of groups a and c did not reach a complete welding process. 17 Out of thirty freshly-extracted human third molars, decay-free, twenty-four cylinders of 5 mm 18 thickness were obtained to perform the test. 19 The device used was a 1070 nm Yb-doped pulsed fiber laser: this source has a maximum average 20 output power of 20 W and a fixed pulse duration of 100 ns, while the repetition rate ranges from 20 21 kHz to 100 kHz. 22 The samples were divided in three groups (a, b, c) of eight teeth and each specimen, with the two 23 portions strictly placed side by side, was put inside the box and irradiated three times, the first and 24 the second at 30 kW and the last at 10 kW power. The frequency was maintained at 20 kHz for all 25 the tests as well as the speed of the beam at 10 mm/sec. 26 The samples of the group a were irradiated without apposition, in the group b nanoparticles (<200 27 nm) of hydroxyapatite were put in the gap between the two portions while in the group c, a 28 powder of hydroxyapatite was employed. 29 Only the specimens of the group b showed a real process of welding of the two parts, while 30 specimens of groups a and c did not reach a complete welding process. 31