A residual pocket probing depth of 6 mm – is it a problem?
PD Dr. Kristina Bertl, PhD MSc MBA
It is a situation we are all too familiar with: following the active phase of treatment, nearly all the patient’s teeth are now unaffected by increased pocket probing depths. However, there are still 1 or 2 places where the treatment goal has unfortunately not been achieved. The following thought might arise: “how bad can it be? A single pocket of 6 or 7 mm – surely that can’t make a big difference?”
However, dentists should not rush to say they are content with residual pocket probing depths. This is because even individual residual pocket probing depths of more than 4 mm constitute a problem, as least in the longer term – both for the affected tooth and for the rest of the dentition.
The data from a Swiss study, which followed approximately 170 patients in maintenance therapy over an average period of 11 years, showed very clearly the problem posed by individual residual pocket probing depths:
- Individual residual pocket probing depths of 6 mm or more were a risk factor for a decline in general periodontal health and for tooth loss.
- Multiple residual pocket probing depths of 5 mm or more were also a risk factor for a decline in general periodontal health.
- Bleeding on probing doubled the risk of later tooth loss.
- The risk of tooth loss was almost 8 times higher for a pocket probing depth (PPD) of 5 mm, about 10 times higher for a PPD of 6 mm, and more than 60 times higher for a PPD of 7 mm!
Conclusion: The treatment goal should be to achieve pocket probing depths of 4 mm maximum and an absence of inflammation!
- Matuliene G, Pjetursson BE, Salvi GE, Schmidlin K, Brägger U, Zwahlen M, Lang NP. Influence of residual pockets on progression of periodontitis and tooth loss: Results after 11 years of maintenance. J Clin Periodontol 2008; 35: 685–695.