I’m by no means an insurance guru, but did the front office staff/office manager mean that only 2 perio maintenance are covered by insurance per year? I’ve never heard of periodontal maintenance only being covered for only 2 years after definitive periodontal therapy. There are so many dental insurance carriers and plans, but I’ve never come across this.
 
To your original question, if once perio maintenance, always perio maintenance; I suspect this thought came about because periodontitis cannot be “cured” only maintained, but what about those that have been maintaining for some time? It does seem fuzzy! According to the American Dental Association (ADA), how long a patient stays on perio maintenance is up to the clinical judgment of the dentist.
 
The ADA states, “This is a matter of clinical judgment by the treating dentist. Follow-up patients who have received active periodontal therapy (surgical or nonsurgical) are appropriately reported using the periodontal maintenance code D4910. However, if the treating dentist determines that a patient’s oral condition can be treated with a routine prophylaxis, delivery of this service and reporting with code D1110 may be appropriate.” (CDT 2009/2010 page 157)
 
So, while many perio patients will need perio maintenance for a lifetime, there is some discretion given for dentists to return a patient to prophy status. Meaning, if a perio maintenance patient has been periodontally stable for a few years, according to the ADA, they can be put back to prophy status if the dentist deems it appropriate. Keep in mind that if a perio maintenance patient returns to a prophy, they cannot go back to periodontal maintenance without undergoing definitive periodontal therapy again.
 
As with anything in dentistry, there is no cookie-cutter answer and all patients should be treated on an individual basis.