# Design and Verification of a New Fixture for Machining of Porous Blocks for Medical CAD/CAM Systems
## 5 Conclusions  
Based on the results shown in this paper, it can be seen that the implementation of fixtures in the medical field provides numerous advantages, which in return aid in better healthcare. Application of FEM analysis proved to be useful for the numerical testing of new designs. In regard to the current design of the fixture for locating and clamping, it showed good results and the ability to be easily implemented for the fabrication of porous material.  
Therefore, based on the obtained results, the following can be summarized and concluded:  
* Stress, displacement, and strain values were calculated for three different preload conditions (10 N, 35 N, and 50 N).
* At 10 N load, the stress was 4.856 \(\times\) 10\({}^{-2}\) MPa. For 35 N and 50 N loads, stress concentrations on the longer edge of the porous block were 1.700 \(\times\) 10\({}^{-1}\) MPa and 2.428 \(\times\) 10\({}^{-1}\) MPa, respectively.
* Displacement at 35 N was 1.269 \(\times\) 10\({}^{-4}\) mm, and at 50 N, it was 1.813 \(\times\) 10\({}^{-4}\) mm, while at 10 N was negligible (it was 3.627 \(\times\) 10\({}^{-5}\) mm).
* Strain values were 2.344 \(\times\) 10\({}^{-6}\) at 10 N, 8.203 \(\times\) 10\({}^{-6}\) at 35 N, and 1.172 \(\times\) 10\({}^{-5}\) at 50 N.
* Dimensional deviations of the machined bone graft were found to be within the range of \(\pm\)0.135 mm, with a peak concentration of +0.015 mm.
* Clamping and machining performance showed that the fixture design reduced the risk of material breakage and deformation, ensuring stability during machining.  
However, the designed fixture in this paper is optimized for specific block dimensions, which limits its versatility. Adjustable or modular designs could address this limitation, offering greater adaptability to varying sizes and geometries by enabling fixtures to be easily disassembled and re-assembled, depending on the dimensions of the workpiece. Future research will involve an upgrade to this design with added elements that would enable quick adjustment of the fixture to facilitate different shapes of porous blocks, thus eliminating the need to have different fixtures for each size of porous block. Furthermore, extending the current analysis to a wider range of biocompatible porous materials would enhance its applicability across diverse medical and dental use cases.  
This continuous development and improvement of fixtures in medicine remains of vital importance for achieving the highest standards in the treatment of patients and improving their quality of life.  
Conceptualization, M.S. and I.B.; methodology, M.S. and D.V.; software, A.M. and Z.S.; validation, A.M. and Z.S.; formal analysis, D.V. and I.B; investigation, M.S. and D.V.; resources, M.S., D.V. and I.B.; writing--original draft preparation, M.S., A.M., Z.S., D.V. and I.B.; writing--review and editing, I.B. and D.V.; visualization, M.S. and A.M.; supervision, I.B. and D.V. All authors have read and agreed to the published version of the manuscript.  
**Funding:** This research has been supported by the Ministry of Science, Technological Development and Innovation (Contract No. 451-03-65/2024-03/200156) and the Faculty of Technical Sciences, University of Novi Sad through project \"Scientific and Artistic Research Work of Researchers in Teaching and Associate Positions at the Faculty of Technical Sciences, University of Novi Sad\" (No. 01-3394/1).  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The original contributions presented in the study are included in the article material, further inquiries can be directed to the corresponding author.  
**Conflicts of Interest:** The authors declare no conflicts of interest.