Browsing by Author "Kuo, Mark Yen-Ping"

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3D laser-printed porous Ti6Al4V dental implants for compromised bone support
(2020-01-01)
Tu, Che Chang
;
Tsai, Pei-, I
;
Chen, San-Yuan
;
Kuo, Mark Yen-Ping
;
Sun, Jui-Sheng
Background/Purpose: Alveolar bone loss following peri-implantitis remains a clinical challenge. We aimed to design a novel bioactive dental implant to accommodate the large bone defect caused by removal of previously failed implant. Methods: Bio-Active(ITRI) dental implant was manufactured with laser-sintered additive 3D printing technique. A 7.5 mm diameter x 7.0 mm depth osteotomy defect was created at the lateral aspect of distal femur of 20 New Zealand white rabbits to simulate the bony defect after removal of failed dental implant. One side of distal femurs was randomly selected for the commercially pure titanium NobelActive (TM) implant (control group) and the other side with Bio-Active(ITRI) Ti-6 Al4V porous dental implant (ITRI group). Animals were sacrificed at 4, 8 and 12 weeks after the implants' insertion. The samples were processed for gross morphological analysis, radiographic examination, micro-CT evaluation, and mechanical testing. Results: In histomorphometrical evaluation and micro-CT analysis, active new bone formation and good osseointegration within the ITRI implants were observed at the bone gap surrounding the dental implants. The biomechanical parameters in the Bio-Active(ITRI) dental implants were significantly higher than those of the commercially control samples. For the Bio-Active(ITRI) dental implants, the trabecular thickness decreased, while the trabecular separation and total porosity increased from the prescribed 1-month to 3-month time points; reflecting the natural remodeling of surrounding bony tissue in the Bio-Active(ITRI) dental implants. Conclusion: The novel porous structured Bio-Active(ITRI) dental implants may have a great potential for the prosthetic reconstruction where bone support is compromised after removal of a previously failed implant. Copyright (C) 2019, Formosan Medical Association. Published by Elsevier Taiwan LLC.
Augmentation of DMLS Biomimetic Dental Implants with Weight-Bearing Strut to Balance of Biologic and Mechanical Demands: From Bench to Animal
(2019-01-01)
Chang, Jenny Zwei-Chieng
;
Tsai, Pei-I
;
Kuo, Mark Yen-Ping
;
Sun, Jui-Sheng
;
Chen, San-Yuan
A mismatch of elastic modulus values could result in undesirable bone resorption around the dental implant. The objective of this study was to optimize direct metal laser sintering (DMLS)-manufactured Ti6Al4V dental implants' design, minimize elastic mismatch, allow for maximal bone ingrowth, and improve long-term fixation of the implant. In this study, DMLS dental implants with different morphological characteristics were fabricated. Three-point bending, torsional, and stability tests were performed to compare the mechanical properties of different designs. Improvement of the weaker design was attempted by augmentation with a longitudinal 3D-printed strut. The osseointegrative properties were evaluated. The results showed that the increase in porosity decreased the mechanical properties, while augmentation with a longitudinal weight-bearing strut can improve mechanical strength. Maximal alkaline phosphatase gene expression of MG63 cells attained on 60% porosity Ti6Al4V discs. In vivo experiments showed good incorporation of bone into the porous scaffolds of the DMLS dental implant, resulting in a higher pull-out strength. In summary, we introduced a new design concept by augmenting the implant with a longitudinal weight-bearing strut to achieve the ideal combination of high strength and low elastic modulus; our results showed that there is a chance to reach the balance of both biologic and mechanical demands.