The field of tissue engineering combines the disciplines of engineering with the life sciences like biology, physiology, pharmacology, and surgery to create replacements for human tissue. It has grown exponentially since my MBA program research focused on bone tissue engineering efforts by startup companies like CURIS, INC. The most common applications in Dentistry now involve the use of allographic materials to repair or replace bone lost due to disease or trauma. Typically, allographic materials like hydroxyapatite, tri-calcium phosphate, de-mineralized cortical or cancellous cadaver bone are used to repair a surgical defect then covered with a collagen-based membrane and/or an autogenous Platelet Rich Fibrin (PRF) membrane to prevent rapid epithelial proliferation and ingrowth into the graft matrix.
The bone graft material serves as a matrix for osteoblastic/osteoblastic activity to remodel the graft material and replace it with new host bone. The use of host derived PRF now allows clinicians to interject a multitude of autogenous stem cells and growth factors like VEGF, TGFB, and BMPs to accelerate the process. Further advances include the use of Volumetric Tomography coupled with 3D printers to design and fabricate scaffoldings from synthetic polymers such as Poly Lactic Acid (PLA) combined with natural polymers like Beta Tricalcium Phosphate and Hydroxyapatite to repair large periodontal defects. The scaffold is 3D printed with selective laser sintering to create the actual structure which was CAD designed from a CBVT scan of the patient’s jaw.
The 3D printing technique allows for the control of such design features as the microarchitecture of the scaffolds to incorporate the right amount of porosity, channels, and grooves required for osteoblast ingrowth, vascular endothelial cell proliferation, and PDL fiber alignment. Furthermore, it now becomes possible to compartmentalize these constructs so that each has defined areas for bone and PDL tissue regeneration containing the appropriate growth factors to enhance tissue growth. This benefits the patients who can now have a CBCT scan of their maxilla or mandible coupled with an intra-oral digital scan to produce a 3D printed scaffold designed by CAD to fabricate a custom bone graft to repair a specific osseous defect increasing the success rate and accelerating the healing time. For the surgeon it allows for a simpler surgical procedure which translate to a better patient experience.
Tobias Fretwurst, DDS,DMD; et al. Periodontal Tissue Bioengineering: Is the Future Now?, Compendium of Continuing Education in Dentistry, 2018; 39(4):218-223.