Compositi rinforzati in fibra di carbonio per sottostrutture implantoprotesiche: aspetti biomeccanici e clinici

The rehabilitation of edentulous or severely compromised dental arches through immediate loading fixed implant dentistry has been proved as a reliable and predictable approach over the last few decades. The rigid spinting of multiple implants through a prosthetic metal framework is a key factor in immediate loading protocols, due to its ability to provide a balanced distribution of chewing loads on each implant and to prevent the concentration of mechanical stresses. However, the high production time-costs and the aesthetic veneer chipping fracture of the prosthesis are the main disadvantages related to the use of metal alloys in implant prosthodontics. Recently a growing interest is emerging towards newly advanced materials, especially on carbon fiber reinforced composites (CFRCs). The aim of this PhD Thesis was to evaluate the biomechanical properties and the clinical behavior of CFRCs applied in implant dentistry. A virtual simulation of occlusal loads distribution with CFRC framework was conducted through a three dimensional Finite Elements Analysis (3D-FEA). Porosity, static and dynamic elastic modulus of CFRC samples, together with shear bond strength between CFRCs and prosthetic veneering materials were evaluated with destructive and non-destructive mechanical tests. Biocompatibility of intact CFRC samples and fragments were investigated by cell count and MTT test, according to EN-ISO 10993-5:2009 directions. A case report of a full-arch immediate loading fixed implant rehabilitation with CFRC framework was included, together with a case series of 5 of full-arch immediate loading fixed rehabilitations supported by zygomatic implants and CFRC frameworks. A prospective cohort clinical study was performed in order to compare full-arch immediate loading fixed implant prostheses with CFRC frameworks versus conventional metal frameworks. Basing on the results of this Thesis, CFRCs might represent a viable alternative to traditional metal alloys for the fabrication of implant prosthetic frameworks thanks to their excellent mechanical properties (enhanced stiffness, fatigue resistance, low weight), biocompatibility, shortened working-time and affordable costs.