Light-field intraoral scanner using solid immersion microlens arrays

Abstract

Dental diagnosis and treatment require structural information of oral tissue in three dimensions. Intraoral scanners based on optical imaging acquire dental impressions immediately while traditional methods replicate oral structure using impression materials with a long workflow. Conventional intraoral scanners often utilize triangulation and confocal scanning for depth estimation. However, these methods still require improvement in system size and measuring accuracy. The simple configuration of a light-field camera (LFC) facilitates an accurate and compact 3D imaging system by inserting microlens arrays (MLAs) in a general camera. This study presents a fully packaged light-field camera as an intraoral scanner using solid immersion microlens arrays (siMLAs). The siMLAs are microfabricated by immersion of conventional thermally reflowed MLAs in PDMS. The extension of f -number from the solid immersion enables light-field imaging with practical spatial resolution and depth-of-field. The depth map of a dental phantom has been successfully reconstructed by the packaged LFC during hand-held operation. This LFC provides a new way for developing a compact in vivo 3D imaging system.