Insurance companies are particular with the protocol and coding for  procedures regarding cleanings.  A routine cleaning (prophylaxis, or prophy for short) consists of scaling and polishing (Code D1110). If a patient comes in with lots of tartar, or other periodontal problems, more than just a one visit prophy is needed.  This might be another cleaning (prophy), or periodontal treatment depending on how bad the findings are.  But if a person needs another cleaning because there was too  much for one visit, or because there are periodontal conditions,  the prophy code D1110 should not be used for the initial cleaning.  Here’s  where insurance gets a little tricky.  In this case, a Gross Debridement code (code D4355) must be used.  Then another cleaning under the prophy code, or if needed, the more aggressive root planing  code can be used.   However, unlike a prophy code, the gross debridement code falls under periodontal treatment  and may not be covered at the same percentage as the  prophy.

So, if you just need a routine cleaning- prophy (D1110)

If you need more than routine cleaning, Gross Debridement code (D4355), followed by either prophy  (D1110)or root planings (D4341).

Now with regard to insurance, the prophy code D1110 is considered a Preventive service ( typically covered at 100%) and is covered as such, but the Gross Debridement code D4355 is considered a Periodontal, or Basic service (typically covered at 75-80%) or in some case even a Major service (typically covered at 50%).