Finite element analysis of different carbon fiber reinforced polyetheretherketone dental implants in implant-supported fixed denture.

OBJECTIVES: The purpose of this study is to determine the feasibility of polyetheretherketone-based dental implants, and analyze the stress and strain around different kinds of dental implants by finite element analysis. METHODS: The radiographic data was disposed to models in Mimics 19.0. 3D models of implants, crowns and jawbones were established and combined in SolidWorks 2018. Appling axial and oblique loads of 100 N, cloud pictures were exported in Ansys Workbench 18.0 to calculate and analyze the stress and strain in and around different implants. RESULTS: Oblique load tended to deliver more stress to bone tissue than axial load. The uniformity of stress distribution was the best for 30% short carbon fiber reinforced polyetheretherketone implants at axial and buccolingual directions. Stress shielding phenomenon occurred at the neck of 60% continuous carbon fiber reinforced polyetheretherketone and titanium implants. Stress concentration appeared in PEEK implants and the load of bone tissue would aggravate. CONCLUSIONS: 30% short carbon fiber reinforced polyetheretherketone implants demonstrate a more uniform stress distribution in bone-implant contact and surrounding bone than titanium. Stress shielding and stress concentration may be avoided in bone-implant interface and bone tissue. Bone disuse-atrophy may be inhibited in PEEK-based implants.

Osseointegration behavior of carbon fiber reinforced polyetheretherketone composites modified with amino groups: An in vivo study.

Polyetheretherketone (PEEK) has become increasingly popular in dentistry and orthopedics due to its excellent chemical stability, reliable biosafety, and low elastic modulus. However, PEEK's biomechanical strength and bioactivity are limited and need to be increased as an implant material. The previous study in vitro has shown that the amino-functionalized carbon fiber reinforced PEEK (A-30%-CPEEK) possessed enhanced mechanical property and bioactivity. This study aims to evaluate the effect of amino groups modification on the osseointegration behavior of carbon fiber reinforced PEEK (30%-CPEEK) in rabbits. Herein, 30%-CPEEK and A-30%-CPEEK implant discs were implanted in rabbit skulls for 5 weeks, with pure titanium implants serving as a control. The bone-forming ability and osseointegration in vivo were systematically investigated by micro-computed tomography analysis, scanning electron microscope observation, and histological evaluation. Our results showed that all detection parameters were significantly different between the A-30%-CPEEK and 30%-CPEEK groups, favoring those in the A-30%-CPEEK, whose appraisal parameters were equal to or better than pure titanium. Therefore, this study supported the importance of amino groups in facilitating the new bone formation and bone-implant integration, suggesting that A-30%-CPEEK with enhanced osseointegration will be a promising material for dental or orthopedic implants.

Enhanced corrosion resistance in an inflammatory environment and osteogenic properties of silicalite-1 coated titanium alloy implants.

The corrosion resistance and osteogenic property of titanium-based implants are crucial for their clinical application. Although they have good stability in standard physiological solutions, limited corrosion resistance in the inflammatory environment is still an unavoidable problem. Herein, the calcined and uncalcined silicalite-1 coatings were synthesized on titanium alloy (Ti-6Al-4 V). The corrosion resistance was investigated by simulating an inflammatory environment in vitro, and osteogenic potential was also evaluated. Here, the uncalcined silicalite-1 coating had the highest corrosion protection efficiency (PE) for Ti-6Al-4 V, which inhibited the metal ion release, surface damage and mass loss in the short-term (7 days) and long-term (30 days). Moreover, positive cell responses, including adhesion, proliferation and osteogenic differentiation of MC3T3-E1 cells, were observed in the uncalcined silicalite-1 coating system, supporting its favorable biocompatibility and osteogenic property. Therefore, these findings indicate that the uncalcined silicalite-1 may be a promising coating strategy for the surface modification of Ti-6Al-4 V implants.

Fabrication and mechanical properties of different types of carbon fiber reinforced polyetheretherketone: A comparative study.

OBJECTIVES: To find alternative non-metallic materials as dental implants for clinical application, different types of carbon fiber reinforced polyetheretherketone were fabricated and investigated. METHODS: Continuous carbon fiber reinforced polyetheretherketone fabrics were fabricated with polyetheretherketone fibers and carbon fibers. Different kinds of carbon fiber reinforced polyetheretherketone were synthesized by setting specific experiment parameters of injection or hot press molding. Various mechanical tests were performed to determine the mechanical properties of different carbon fiber reinforced polyetheretherketone, pure polyetheretherketone and pure titanium. RESULTS: Polyetheretherketone composites presented outstanding mechanical and thermal properties after incorporating carbon fiber. The bending and tensile strength of short carbon fiber reinforced polyetheretherketone were close to human bone, and the bending strength of continuous carbon fiber reinforced polyetheretherketone reached 644 MPa, even higher than that of pure titanium. CONCLUSIONS: The mechanical properties of polyetheretherketone composites are more similar to bone tissue than titanium, and the stress shielding phenomenon may be inhibited. They may become promising materials as substitutions for titanium and prospective materials in bone tissue engineering.

Application of biomolecules modification strategies on PEEK and its composites for osteogenesis and antibacterial properties.

As orthopedic and dental implants, polyetheretherketone (PEEK) is expected to be a common substitute material of titanium (Ti) and its alloys due to its good biocompatibility, chemical stability, and elastic modulus close to that of bone tissue. It could avoid metal allergy and bone resorption caused by the stress shielding effect of Ti implants, widely studied in the medical field. However, the lack of biological activity is not conducive to the clinical application of PEEK implants. Therefore, the surface modification of PEEK has increasingly become one of the research hotspots. Researchers have explored various biomolecules modification methods to effectively enhance the osteogenic and antibacterial activities of PEEK and its composites. Therefore, this review mainly summarizes the recent research of PEEK modified by biomolecules and discusses the further research directions to promote the clinical transformation of PEEK implants.

The antibacterial property of zinc oxide/graphene oxide modified porous polyetheretherketone againstS. sanguinis, F. nucleatumandP. gingivalis.

About 30% failures of implant are caused by peri-implantitis. Subgingival plaque, consisting of S. sanguinis, F. nucleatum,P. gingivalis et al, is the initiating factor of peri-implantitis. Polyetheretherketone (PEEK) is widely used for the fabrication of implant abutment, healing cap and temporary abutment in dental applications. As a biologically inert material, PEEK has shown poor antibacterial properties. To promote the antibacterial activity of PEEK, we loaded ZnO/GO on sulfonated PEEK. We screened out that when mass ratio of ZnO/GO was 4:1, dip-coating time was 25 min, ZnO/GO modified SPEEK shown the best physical and chemical properties. At the meantime, the ZnO/GO-SPEEK samples possess a good biocompatibility. The ZnO/GO-SPEEK inhibitsP. gingivalisobviously, and could exert an antibacterial activity toS. sanguinisin the early stage, prevents biofilm formation effectively. With the favorablein vitroperformances, the modification of PEEK with ZnO/GO is promising for preventing peri-implantitis.

Minimally invasive maxillary sinus augmentation with simultaneous implantation on an elderly patient: A case report.

BACKGROUND: In this case study, a minimally invasive transalveolar approach using platelet-rich fibrin and bone substitute with simultaneous implantation was carried out in an elderly patient. We analyzed the cone-beam computed tomography (CBCT) findings to evaluate bone regeneration. CASE SUMMARY: A 65-year-old female with no contraindications for dental implants and loss of maxillary bilateral molars is described. Examination by CBCT showed the available vertical bone height in the bilateral posterior maxilla was 0.5-6.8 mm in the left and 2.8-6.5 mm in the right. The patient underwent a transalveolar approach using platelet-rich fibrin and bone substitute with simulataneous placement of an implant 10 mm in length. Six months post-surgery, the implant showed excellent osseointegration with the bone graft. Thereafter, full-ceramic crowns were fitted. Follow-up at 2 years demonstrated satisfactory prognosis. CONCLUSION: Platelet-rich fibrin and bone substitute can be used to augment the maxillary sinus with a vertical bone height less than 4 mm.