If I understand the nature of the collaberation it would take Varasani's technique to live print Si3N4 and combine that with Sintx Si3N4 SiYAlON is my guess or a combination or SiYAlON & Bioglass.
The only thing that I think that could compete is Bal and Rahaman's work int bioceramics for the application. Remember copper is antibacterial, and I dont think they have to share with SINTX if they took that route. Really wouldnt care if it looked more promising in the research compared to SiNi. Maybe it's all SiNi and SINTX gets payed. Hope they all get a royalty on rediheal too.