Applications of Near-IR CW and Ultrafast Pulsed Lasers and Photo-active Biominerals in Reconstructive and Restorative Surgery of Hard Tissues

The emergence of ultrashort pulsed near-IR lasers has opened novel opportunities not only for investigating the physics of interaction of such lasers with photo-active biomaterials for reconstructive and restorative bone and dental tissue engineering, but also for analysing the light-matter interaction in the CW laser regime for reconstructive surgical applications. The clinically-relevant examples discussed are for enamel restoration, osteoporotic bone-mass augmentation, and reconstructing damaged bone after trauma. Here, we explain the process of energy absorption in both the CW and ultrashort-pulsed regimes using the heat transfer process which impacts on the mineralisation of tissue. The aspect of thermal management by controlling the repetition rates of ultrashort pulses in near-IR lasers is also explained using sub-ablation and ablation models which are particularly relevant for dental tissue surgical reconstruction. On the other hand, for bone applications both the CW and ultrashort pulsed laser become highly relevant, depending on the type of clinical case for reconstructive surgery. The presentation will also explain the cell/human stem-cell biological characterisations of the laser-treated biomineral scaffolds in vitro for testing the toxicity, cell viability, and proliferation analyses. We will conclude by explaining the need for regulatory process, safety procedures needed prior to animal and first-in-human studies.