Novel design of additive manufactured hollow porous implants. Issue 11 (November 2020)

• Record Type: Journal Article
• Authors: Huang, Chih-Chieh; Li, Ming-Jun; Tsai, Pei-I; Kung, Pei-Ching; Chen, San-Yuan; Sun, Jui-Sheng; Tsou, Nien-Ti
• Is Part Of: Dental materials. Volume 36:Issue 11(2020)
• Page Start: 1437
• Page End: 1451
• Publication Date: 2020-11
• Subjects: Dental implants -- Additive manufacturing -- Mechanical testing -- Micro-CT -- Mechano-regulatory algorithm -- Finite element method; Dentistry -- Periodicals; Dental materials -- Periodicals; 617.695
• DOI: 10.1016/j.dental.2020.08.011
• Languages: English
• ISSNs: 0109-5641

Abstract

Graphical abstract: Highlights: The properties and performance of porous implants were examined by in vitro mechanical test, in vivo micro-CT and ex vivo pull out test. The results prove that the proposed porous implants can provide good fixation and improve the osseointegration. Several features were accurately predicted by the three-dimensional mechano-regulation model developed in this work. The proposed FE model may reduce the demand of animal tests and is sufficiently general for different dental implants. Abstract: Objective: Our aim is to examine the mechanical properties of two types of additive manufactured hollow porous dental implants and 6 and 12-week bone ingrowth after insertion in animals. A 3D numerical model is also developed to show detailed tissue differentiation and to provide design guidelines for implants. Methods: The two porous and a commercial dental implant were studied by series of in vitro mechanical tests (three-point bending, torsional, screwing torque, and sawbone pull-out tests). They also evaluated by in vivo animal tests (micro-CT analysis) and ex vivo pull-out tests. Moreover, the mechano-regulation algorithm was implemented by the 3D finite element model to predict the history of tissue differentiation around the implants. Results: The results showed that the two porous implants can significantly improve osseointegration after 12-week bone healing. This resulted in good fixation and stability of implants, giving very high maximum pull-out strength 413.1 N and 493.2 N, compared to 245.7 N for the commercial implant. Also, several features were accurately predicted by the mechano-regulation model, such as transversely connected bone formation, and bone resorption occurred in the middle of implants. Significance: Systematic studies on dental implants with multiple approaches, including new design, mechanical tests, animal tests, and numerical modeling, were performed. Two hollow porous implants significantly improved bone ingrowth compared with commercial implants, while maintaining mechanical strength. Also, the numerical model was verified by animal tests. It improved the efficiency of design and reduce the demand for animal sacrifice.