Development of electrospun piezoelectric materials for dentistry

Abstract

Wearable technology has recently become a hot topic in the science and technology community. It has been widely used in health management and medical care, and can realize functions such as physiological parameter monitoring, disease prevention and diagnosis, and health data management. Health awareness has been paid attention by clinician and public, and more recently towards to oral health detection and oral disease prevention. Therefore, wearable oral health electronic devices have great development potential. Piezoelectric materials, as materials that can convert mechanical energy into electrical energy, have been widely used in sensors, transducers, and drivers, and applied in ultrasound, electroacoustics, medicine and other fields. Although piezoelectric materials have recently been used in bone regeneration, tissue regeneration and piezoelectric osteotomy in the dental field, there is still a lack of research and products in the fields of oral sensor monitoring and oral disease therapy.

This study was dedicated to the development of electrospun piezoelectric flexible materials-based devices for oral health detection and disease therapy. First, the preparation of electrospun PVDF-based nano zirconia (ZrO2) containing piezoelectric composites was optimized, and the composites were characterized to obtain the optimal spinning parameters and fibre membrane processing parameters before the assembly. Then, a new one-step bite force test method was developed by using the principle of the positive piezoelectric effect and electrospun piezoelectric materials as signal conversion media. In addition to developing a piezoelectric materials-based bite force testing system, a self-powered oral energy harvesting device based on PENGs was also developed. After developing a wearable oral health device based on piezoelectric materials, biocompatibility tests, including cell proliferation, viability and morphology, and metal ion release was testified.

The results revealed that factors such as the PVDF dissolve temperature, electrospinning voltage, volume ratio of the reagents in the solvent system, and ZrO2 nanoparticle concentration can significantly affect the fibre morphology. ZrO2 nanoparticle concentration, electrospinning voltage, membrane collector rotating speed, membrane annealing temperature, applied pressure and frequency can affect the piezoelectric output obviously. The PENGs based bite force testing system exhibited excellent accuracy and linearity, with a short operating procedure, making it an alternative to commercial bite force tests. Among the PENGs based aligner and mouthguard, the 2-layer mouthguard exhibited higher piezoelectric output, which provided the possibility for the realization of a self-powered oral healthcare devices for e.g. photodynamic therapy (PDT). The extracts experiment results of the electrospun PVDF/ZrO2 composites and electrospun PVDF-based PENG showed that the composites and piezoelectric oral devices showed good in vitro biocompatibility.

In conclusion, this biosafe piezoelectric materials have shown great promise for dentistry, especially for wearable and self-powered microdevices for oral health monitoring and disease therapy. Ultimately, more piezoelectric materials and piezoelectric materials-based devices can be applied to the dental field which should be beneficial to human oral and general health in the near future.