Clinical supplies should run roughly 5 to 8 percent of collections in an endodontic practice. It is a smaller line than staff or facility, which is precisely why it drifts: nobody flags a category this size until it is well out of range.
The drift is usually not overuse. It is pricing. Supply and lab pricing that was competitive three years ago rarely stays competitive on autopilot, and vendors count on you not re-checking.
Rotary files, obturation materials, irrigants, and single-use items add up because volume is high even if unit cost is low. A few percent off across the catalog is real money at practice scale.
The fastest wins: re-quote your top ten SKUs by spend, confirm you are getting the tier pricing your volume qualifies for, and check whether a buying group or manufacturer program applies to you.
If you have not renegotiated supply and lab pricing in two years, assume there is money in this line. It is one of the lowest-effort overhead fixes available, and it recurs every year once done.