The titanium PV I endosteal implant from beta-titanium alloy Ti 38Nb 6Ta.

AIM: The aim of this study was to use the beta-titanium alloy Ti38Nb6Ta for production of a new construction line of implants, perform testing on animals and preclinical tests. MATERIALS AND METHODS: Within this study, a new PV I implant with five construction variants was developed. The implant includes three types of threads - microthreads and flat threads of two types with a different depth. Further, the PV I implant was tested on minipigs. Subsequently, preclinical tests of 150 implants were performed and assessed. The age interval of patients was from 18 to 74 years. RESULTS: Beta titanium alloy exhibited higher strength than titanium alloys. Anti-corrosion resistance was also higher. The implant from beta-alloy was inserted in the tibias of minipigs. Sections showed good osseointegration of the PV I implant. During the preclinical tests, 150 implants were inserted with the success rate of 99.33% after the two year assessment. The assessment also included handicapped patients who are not usually assessed in classical studies. Finally, the implantation protocol and documentation of a new implantation system PV I was designed. At the same time the industrial sample of this implant was formed and accepted. CONCLUSION: A new anti-rotation PV I implant with microthreads and conical anchorage of the abutment into the fixture was formed. The beta-titanium alloy Ti38Nb6Ta used for the implant was biocompatible and had higher mechanical and physical properties than the existing titanium alloys. The PV I implant was recommended for clinical application.

Bilinear elastic property of the periodontal ligament for simulation using a finite element mandible model.

This study aimed to introduce a procedure for determining the bilinear elastic moduli (E1 and E2) of the periodontal ligament for a mathematical tooth model to analyse stress in the mandible. The bone and tooth morphology were scanned from a dry skull and an extracted intact tooth, respectively, and reconstructed in a three-dimensional finite element model. The model showed good agreement with previously reported in vivo premolar movement when an E1 for the first phase tooth movement of 0.05 MPa and an E2 for the second phase of 8.0 MPa with ε(12) of 0.075 were adopted. The mandible model analysis indicated that a remarkably high maximum compressive stress in the cervical cortical bone and the tensile stress in areas of masticatory muscle attachment were found. Future stress analyses using a jaw model may follow the process of determination of bilinear moduli to enhance accurate simulation with less calculation time.

Diffractive-optics-based sensor as a tool for detection of biocompatibility of titanium and titanium-doped hydrocarbon samples.

Adsorption of the elongated human plasma fibrinogen (HPF) and globular human serum albumin molecules on a titanium-based surface is monitored by analyzing permittivity and optical roughness of protein-modified surfaces by using a diffractive optical element (DOE)-based sensor and variable angle spectro-ellipsometry (VASE). Both DOE and VASE confirmed that fibrinogen forms a thicker and more packed surface adlayer compared to a more porous and weakly adsorbed albumin adlayer. A linear relation of the permittivity (ε(')) and dielectric loss (ε('')) was found for some of the dry titanium-doped hydrocarbon (TDHC) surfaces with excellent HPF adsorption ability. We discuss some aspects of TDHC's aging and its possible effects on fibrinogen adsorption.

Fixed bicortical screw and blade implants as a non-standard solution to an edentulous (toothless) mandible.

AIM: This paper deals with the treatment of an atrophied toothless mandible with a fixing bridge carried by two nonstandard implant systems. METHODOLOGY: Four bicortical screws were implanted into the frontal part of the mandible and one implant on each side was placed into the distal area of the mandible as a support for a fixing bridge. RESULTS: During the years 2002 - 2007 the authors placed a total of 256 bicortical screw and 84 blade implants. During this period only four bicortical screws and one blade implant failed. The primary and secondary surgical success rate was therefore above 98%, while the prosthetic success rate was 100%. (Bridges which had to be re-fabricated due to implant failure were not taken into account.) CONCLUSION: This approach is recommended as a highly successful and affordable option for a wide range of patients.

Sensing of human plasma fibrinogen on polished, chemically etched and carbon treated titanium surfaces by diffractive optical element based sensor.

Adsorption of human plasma fibrinogen (HPF) on 6 differently treated titanium samples (polished, polished and etched, and 4 titanium carbide coatings samples produced by using plasma-enhanced chemical vapour deposition (PECVD) method) is investigated by using diffractive optical element (DOE) sensor. Permittivity (susceptibility) change and fluctuation in optical roughness (R(opt)) of treated titanium surface in the presence of background electrolyte without and with HPF molecules are sensed by using DOE sensor and optical ellipsometry. Correlation between transmitted light and thickness of molecule layer was found. The findings allow to sense temporal organization and severity of adsorption of nano-scale HPF molecules on polished, on polished and etched, and on titanium carbide surface.