Numerical Optimization of Cutting Parameters for Texturization of Dental Implants
摘要
The surface texture of implants was shown to be an important factor in decreasing the intensity of the body's immunological response towards them and guaranteeing their longevity. Currently, regarding dental implants, an average surface roughness ( \({S}_{a}\) ) between 1 and 2 μm is the norm, as that allows for better osseointegration. Many kinds of surface treatments may be used to obtain roughness in that range, each one having its own characteristics and roughness ranges. However, it should also be possible to obtain such surfaces using ultrasonic elliptical turning, but in order to obtain the desired surface, it is necessary to obtain the right set of cutting parameters. This paper, therefore, aims to develop a method to calculate the cutting parameters needed to such surface, basing itself on topography simulation and conventional optimization. The method consists on using shape functions which are capable of reproducing the shape of the surface to be obtained in function of the cutting parameters (being based specifically on feed rate and cutting speed) and using gradient-based optimization methods to find the optimal parameters. The method was implemented and tested considering a problem of maximization of surface area with a roughness constraint, problem developed considering the needs of dental implants. The implementation was shown to be capable of consistently obtaining a surface with the desired characteristics. However, a simplified mathematical model was used, and experimental validation was not done, matters which shall be dealt with in future research.