Enhanced performance of 3D-printed biomaterials with composite approach

Lappalainen Reijo

Abstract

Our natural bone and tooth tissues are based on a complex hierarchical structure utilizing collagen fibers bundled to­gether with proteins and reinforced with ceramic mineral crystals such as hydroxyapatite. Furthermore, fine-tuning of the composition and structural features allows building layered structures such as cancellous porous bone covered by a high-density hard cortical bone or an elastic dentine core of a tooth with a hard enamel surface layer. These lead to optimal performance. In modern restorative dentistry, the aim is to match properties of the restoration and the tooth to achieve good long-term performance. Multicompo­nent composites are developed with biomimetic scope, i.e. to mimic natural tooth structure and function. Convention­ally particulate filler composites (PFC) are used but more re­cently such as short fiber-reinforced composites (SFRC) and nanofiller composites have been developed. Furthermore, current composites utilize light, chemicals or their combina­tion for curing. By composite approach several advantageous properties of biomaterials have been achieved such as greater stiffness, higher elastic limits, higher fracture resistance and lower wear.Different materials and composites have emerged in 3D-printing techniques in medical industry and even clin­ical practice allowing producing well-controlled designs with complex structure, composition and shapes. 3D printing is currently used to fabricate, e.g. surgical tools and guides, pa­tient-specific surgical models, removable dentures, splints, scaffolds, facial prostheses and orthodontic aligners. The use of these materials and products is slowly moving from temporary to permanent restorations.