Generally speaking if the slab has come away completely and there is no pulp exposure I leave them and just advise they are monitored regularly for further damage/ decay. Once the tooth has lost the enamel the exposed dentine is softer and more susceptible to decay.
If the slab has fractured down below the gum line then there is increased chance of progressive periodontal disease but if you are able to keep up the oral hygiene regime then you can likely keep that at bay.
And as others have said, avoid antler chews, they are too hard.