Sir, I thank Mr Greene for his letter (BDJ 2014; 217: 388–389). If all patients behaved in the same way, ie like compliant robots, I would agree with him.

I also agree that using the BPE to monitor periodontal disease, from the dentist's perspective, is like telling the time with a calendar. However, from the patient's perspective the micro view may be counter-productive in the early stage of the pathway to periodontal health. What is needed initially to assess an individual is an overview and not the specifics.

A behavioural approach to treating patients requires skilled application of principles to have the best outcomes in terms of patient compliance. I think we'd all agree that responsible biofilm control is key to periodontal health and that can only reasonably be achieved by the individual patient. Dentists and particularly GDPs have the responsibility to interact with patients in a way that demonstrates the application of sound principles.