Preclinical Development of a Novel Bioactive Glass Cement for Bone Graft Substitution in Dentistry

当牙齿被拔出时，牙根周围的骨骼不再接受与咀嚼或咬合等功能相关的物理刺激，其结构开始改变。这种骨的重塑（去除和替换骨）导致净骨丢失。如今，牙科植入物是最常见的治疗方法，用于替换缺失的牙齿。牙科植入物由钛螺钉组成，一旦植入颌骨，钛螺钉就会取代牙根。它们需要下面和周围的骨组织作为支撑，以正确地融入颌骨。长时间无牙（没有牙齿）的人可能会遇到牙科植入物的问题，因为他们可能没有足够的骨留在牙槽中，或者植入物的插入可能会受到骨缺失区域的限制。为了克服这些问题，通常使用骨样材料来完全填充拔牙后的骨窝或填充牙科植入物周围的骨缺损。最常见的材料是合成磷酸钙化合物。这些为骨再生提供了最大的潜力，因为它们具有与原始骨的矿物质成分相似的组成。其使用的基本原理是，它们将防止拔牙后骨的生理重塑/改变，并促进骨缺损内的新骨形成。本研究项目的目的是评估一种新型可注射材料用于替代种植牙科中缺失骨的有效性。它的物理、化学和生物学特性已经在我们以前的研究中得到证实。因此，下一阶段将专注于特定的临床牙科应用。我们想评估两种新型可注射磷酸钙骨替代材料的体内性能。目前，所有骨替代材料都可作为颗粒用于临床，这些颗粒不会硬化成单个结构。因此，材料可以部分地从该部位迁移，作为小颗粒进入口中，这导致手术失败。我们的材料是一种类似于腻子的可注射糊剂，可以很容易地成型为所需的形状，它们基本上是骨架的聚合物填料。我们材料的新奇之处在于，它们在注入骨骼后几分钟内硬化，确保完全填充部位的空隙，而不会在植入后发生任何部件移位。我们的材料具有出色的操作性能和易用性，从而简化了手术程序，从而缩短了手术时间，使患者和手术团队受益。初步调查表明，我们的材料整合良好，与骨牢固结合，与用于相同应用的其他材料相比，以更快的速度促进新骨形成。在本研究中，我们将使用动物模型比较这两种测试材料在拔牙后保持骨尺寸和促进牙种植体周围新骨形成的能力方面的性能与牙科常用的标准材料进行直接比较。在牙科中引入这些新型可注射材料将有助于克服目前可用的其他合成材料的局限性，例如与外科手术失败相关的低降解速率、较差的处理性能和植入部位的低稳定性。将这种材料用于种植牙科的临床应用将有利于患者，因为它将导致更好的结果，更快的愈合时间和更短的完成最终修复所需的时间。该项目将提供CE标志所需的所有科学数据，这是许可我们产品的必要条件，并将材料投入临床应用。

When a tooth is extracted, the bone surrounding that tooth root no longer receives a physical stimulation connected to functions such as chewing or biting and its structure starts to alter. This remodelling (removing and replacing bone) of the bone results in net bone loss. Nowadays dental implants are the most common treatment for replacing a missing tooth. Dental implants consist of titanium screws that replace the root of a tooth once they are placed into the jawbone. They require bone tissue underneath and surrounding them for support to properly integrate into the jaw. People who have been edentulous (without teeth) for a prolonged period may encounter problems with dental implants as they may either not have enough bone left in the tooth socket or the insertion of the implant could be limited by the presence of areas of missing bone. To overcome these problems a bone like material is commonly used to entirely fill the bone socket after tooth extraction or fill a bone defect around the dental implant.The most common materials available are synthetic calcium phosphate compounds. These offer the greatest potential for bone regeneration since they have a composition similar to the mineral components of the original bone. The rationale behind their use is that they will prevent the physiological remodelling/alteration of the bone after tooth extraction and promote new bone formation within the bone defect.The aim of this research project is to assess the efficacy of a novel injectable material used to replace missing bone in implant dentistry. Its physical, chemical and biological properties have already been proven in our previous studies. Therefore, the next stage is to focus on specific clinical dental applications. We want to assess the in-vivo performance of two novel injectable calcium phosphate materials for bone replacement. Currently all bone substitute materials are available for clinical use as granules that do not harden into a single construct. As a consequence the material can partially migrates from the site, coming out as small granules into the mouth, which leads to a failure of the procedure. Our materials is an injectable pastes similar to putty that can be easily moulded into the desired shape, they are essentially polyfillers for the skeleton. The novelty of our materials is the fact that they harden in a few minutes after being injected into the bone, ensuring a complete void filling of the site without any parts becoming dislodged after the implantation. Our materials show excellent handling properties and ease of use, which leads to a simplification of the surgical procedure and consequently, a shorter surgical time which benefits both patients and the surgical team involved. Initial investigations have demonstrated that our materials integrate well, bind strongly with bone and enhance the formation of new bone at a faster rate compared to other materials used for the same applications.In this study we will use animal models to compare the performance of these two test materials with regard to their abilities to preserve the dimensions of the bone after tooth extraction and promote new bone formation around dental implants in direct comparison with a standard material commonly used in dentistry. The introduction of these novel injectable materials in dentistry will help to overcome the limits of other synthetic materials currently available, such as low degradation rate, poor handling properties and low stability in the site of implantation, which are associated with failures of the surgical procedure. The clinical use of this material for implant dentistry will be beneficial for patients as it will lead to better outcomes, faster healing times and a shorter time required for completion of the final restoration. This project will provide all scientific data required for a CE mark, a requisite for licensing our products and will take the materials into clinical application.