Just about everything should be able to be printed without supports.  Material of choice can be used, but I'd recommend something on the order of PETG strength or greater given the nature of hex interfaces.  Interlocking dovetails of the bone and gingiva models may need to be inserted and reinserted after first printing depending on your resolution.  Recommend FDM printing, but could potentially be done in resin.  Act like a doctor and print your own toys!