CROWN

Motivation:
Worldwide, 23 million dental crowns are placed each year to replace damaged or lost teeth. High-quality, durable, and aesthetically pleasing ceramic crowns cost up to $1,500 and are therefore unaffordable for many patients. As an alternative, low-cost products made of metal or plastic from the Far East are used, to the detriment of patients as well as German and European suppliers of high-quality products. The reason for the high price of ceramic crowns is a multi-step process chain consisting of individual steps, some of which are performed by hand.

Objectives and Approach:
The objective of the CROWN collaborative project is to develop a machining process that automatically performs all process steps for the fabrication of high-quality ceramic crowns from sintered ceramic on a single machine. To this end, an abrasive waterjet milling process is being implemented and controlled using a novel hybrid optical sensor concept. In this process, a NIR-OCT sensor measures the surface of the machined ceramic inline. A second quantum OCT sensor detects subsurface defects using entangled MIR-NIR photons.

Innovations and Prospects:
Direct machining can reduce the cost of a high-quality ceramic crown by 98% to $30. This would ensure widespread access to high-quality dental restorations for the European population. With this unique selling proposition, HydroMill GmbH could secure technological leadership in the European dental milling machine market, which is valued at 750 million euros. In the medium term, the significant cost reduction would result in the relocation of dental crown production from low-wage countries back to Europe.