Phosphate Bio-mineral-Ultrafast Laser interaction - a pathway for future hard tissue re-engineering (Novel Tool for Surgical technologies) - LUMIN

特别是由于食物和饮料的摄入引起的酸侵蚀以及由于牙齿的一般磨损引起的牙齿表面损失是一个全球性的问题。牙齿表面牙釉质的持续侵蚀和损失会导致过敏。这种口腔疾病在儿童和社会老龄化人口中都很严重，并可能对生活质量产生重大影响。2011年的人口普查指出，英格兰和北爱尔兰有16.3%的人口年龄在65岁以上（每日电讯报2012年7月17日），这表明在未来几年遭受酸侵蚀的人数可能会继续上升。这意味着有一个更迫切需要提供一个强大的解决方案来恢复丢失的牙釉质，这是一个仍然难以解决的问题。为了解决这个问题，我们建议研究一种工程方法，在牙齿上喷上一层薄薄的矿物层，然后使用超快激光照射脉冲将其致密并粘合到牙齿上。跨学科的LUMIN项目将在任务(a)中开发和利用微喷嘴生物矿物输送技术，并随后使用飞秒脉冲（fsp）激光烧结，用于修复酸侵蚀的牙釉质。所提出的fsp激光器的工作波长将在近红外（1500-2100 nm）的人眼安全区域内，并将通过设计激光腔提供能量/功率输送方面的灵活性，这是任务(b)的主要目标。如上述目标部分所述，任务(b)的另一个目标是将任务(a)的微喷嘴生物矿物输送系统与激光在单一平台上集成，以实现沉积的生物矿物层在酸侵蚀牙釉质表面的快速烧结。在这项研究中，新型的耐酸搪瓷矿物替代品，以晶体和凝胶形式，将被设计和优化用于任务(a)中的微喷嘴输送。材料输送系统与fsp激光的集成将产生同步烧结。因此，这里的工程方法将产生3种不同的平台技术，供未来开发，这将在利兹组织工程和医疗技术综合知识中心的支持下实现。我们将研究用fsp激光对凝胶和悬浮液材料使用微喷嘴是否会由于纳米级颗粒的产生和释放而产生毒性风险（有些人可能会认为这些颗粒可能被fsp激光的强光束光敏化）。因此，在任务(c)中，我们将评估任何纳米颗粒和光致毒性，并进行风险分析。这将符合标准的临床程序，目的是识别和减少任何迫在眉睫的风险。在任务(c)之后，我们在任务(d)中的目标是实施任务(a)和(b)中开发的工程方法，以及任务(c)中的风险缓解策略，使用原位口腔器具试验在口腔环境中测试fsp激光烧结牙釉质矿物，这是利兹牙科研究所首创的一项技术，旨在最大限度地降低大量体内试验中的风险。在任务(d)中，将使用材料科学、工程和临床牙科方面的学术专业知识，对烧结材料进行酸侵蚀、耐久性、硬度、韧性和弯曲弯曲的表征。IKC团队将通过Graeme Howling博士的专业知识提供支持，首先通过项目合作伙伴M-Squared激光器、British Glass和Giltec开发技术。该项目还旨在与海外学术机构建立学术联系，例如里海的IMI和宾夕法尼亚州立大学的材料科学，以及通过SUPA领导的EPSRC资助的合作与美国的斯坦福大学和Caltec大学建立学术联系。与英国Photonics KTN的产学研联系也有望在项目过程中得到发展。

Acid erosion due to food and drink intake in particular and tooth surface loss due to general wear of the dentition is a global problem. Continual erosion and loss of the surface enamel of the tooth leads to hypersensitivity. This oral condition is acute in both children and the ageing population of society and can have a significant impact on the quality of life. The 2011 census points out that 16.3% of the population of England and N Ireland is above 65 years old (Daily Telegraph 17 July 2012), which suggests that the number of people suffering from acid erosion may continue to rise in years to come. This means that there is an even more urgent need to provide a robust solution for restoring lost enamel, a problem that remains intractable for clinical dentistry. To address this problem, we propose research into an engineering methodology to spray the tooth with a thin mineral layer that is then densified and bonded to the underlying tooth using an ultrafast laser irradiation pulse. The cross-disciplinary LUMIN project will develop and exploit the technology of micro-nozzle bio-mineral delivery in Task (a) and its subsequent sintering using femto-second pulsed (fsp) lasers for the restoration of acid-eroded enamel. The operating wavelength of the proposed fsp lasers will be in the eye-safe regions of the near-IR (1500-2100 nm) and will offer flexibility in terms of energy/power delivery by engineering the laser cavity, which is the main goal of Task (b). An additional goal of Task (b), as stated in the objective section above, is to integrate the micro-nozzle bio-mineral delivery system from Task (a) with lasers on a single platform for achieving rapid sintering in the deposited bio-mineral layers on to the acid-eroded enamel surface. During this research, novel acid-resistant enamel mineral substitutes, in crystalline and gel forms, will be engineered and optimized for the micro-nozzle delivery in Task (a). The integration of the materials delivery system with the fsp-laser will then yield simultaneous sintering.. The engineering approaches herein will therefore yield 3 different platform technologies for future exploitation, which will be achieved with the support from the Integrated Knowledge Centre on Tissue Engineering and Medical Technologies at Leeds. We will investigate whether the use of a micro-nozzle for gel and suspension materials with an fsp-laser poses a risk of toxicity due to generation and release of nano-scale particulates (some may argue these might be photosensitized by the intense beam of the fsp-laser). In Task (c) we will therefore assess any nano-particle and photo-induced toxicity and perform a risk analysis. This will conform to standard clinical procedures with an aim to thus identify and minimise any imminent risk. Following Task (c), our goal in Task (d) is to implement the engineering approaches, developed in Tasks (a) and (b) together with the risk mitigation strategy in Task (c) for testing fsp-laser sintered enamel minerals in the oral environment using in-situ mouth appliance trials, a technique pioneered at the Leeds Dental Institute to minimising the risks in extensive in-vivo trials. In Task (d) the sintered materials will be characterised for acid erosion, durability, hardness, toughness, and flexural bend with using the assembled academic expertise in materials science and engineering and clinical dentistry.The IKC team will provide support, via Dr. Graeme Howling's expertise, to develop technology exploitation through the project partners, M-Squared Lasers, British Glass, and Giltec in the first instance. The project also aims to establish academic links with overseas academic institutions e.g. the IMI at Lehigh and Penn State in Materials Science, and with Stanford and Caltec in the US via the SUPA led EPSRC funded collaboration. The industry-academia link with the Photonics KTN in the UK is also expected to develop during the course of project.