Not much to add to Ryan's comments above. Yes, it does seem to me that the combination of silica sand and Melanoides snails does reduce the need to trim the teeth on Colomesus puffers. Put another way, when I replaced the sand with gravel, I found their teeth growing much more rapidly! I've now returned to keeping them in a tank with sand and snails.
I'm not sure this approach would remove the need to trim their teeth permanently. Not kept them for a full lifespan yet, so no data. But as Ryan has said, there's no big deal to trimming teeth. Clove oil sedates the fish very quickly and safely, and using cuticle clippers it is literally a few seconds' work to do the actual trimming. Once returned to the aquarium they regain normal behaviour in a few minutes.
If you want to avoid teeth trimming as much as possible, keep them in a pufferfish-only aquarium. This way you can feed them exclusively hard foods like unshelled shrimp, snails, krill and so on. Unshelled shrimp are great, because you can hand-feed the puffers the eyeballs and legs and they will crack away at these food item, wearing down their teeth in the process. But SAPs prefer softer food (they love bloodworms) and if you keep them in a mixed species environment they will often fill up on those foods instead of the crunchy stuff. So if possible, keep in a single-species (or at least pufferfish-only) aquarium.
SAPs are by far the hardiest pufferfish in the hobby. I highly recommend them.
Cheers, Neale