Probing pressure, a highly undervalued unit of measure in periodontal probing: a systematic review on its effect on probing pocket depth

Aim: To investigate the influence of probing pressure on the probing pocket depth (PPD) in diseased and healthy periodontal tissue conditions through a systematic review. In addition, to facilitate comparison of the study outcomes, an attempt was made to provide a correction factor that compensates for the different probing pressures used.

Material and Methods: The MEDLINE-PubMed and Cochrane Central Register of controlled trails (Central) were searched up to June 2008 to indentify appropriate studies.

Results: The search yielded 3032 titles and abstracts. In total, five papers fulfilled the eligibility criteria. These studies provided data with probing pressures ranging from 51 to 995 N/cm2. For the evaluation of the results a distribution was made between diseased and healthy/treated sites. The incremental change in PPD in healthy/treated sites decreased as the pressure increased above 398 N/cm2. In diseased sites, this phenomenon was already present at pressures above 100 N/cm2. At healthy/treated sites, a mean increase of PPD of 0.002 mm per increase of 1 N/cm2 in probing pressure could be calculated whereas at diseased sites this value amounted to 0.004 mm.

Conclusion: The results show that with increasing probing pressure, the PPD increases. The dimensions of the increase are dependent on the periodontal tissue conditions