Clinical characteristics of periodontal sites with probing attachment loss following initial periodontal treatment

Periodontal sites which had undergone probing attachment loss were identified in 16 advanced periodontitis patients subjected to initial periodontal treatment and monitored every 3rd month for 42 months. Many sites with probing attachment loss showed no increase in probing depth and bled on probing at a few of the examinations during maintenance. Others showed increase in depth, frequent bleeding and suppuration. An arbitrary classification of 'questionable periodontitis' sites was used and included sites with the following characteristics: probing depth at 42 months < or = 3.5 mm + bleeding on probing at no more than 5 of the 14 examinations 3-42 months + no suppuration on probing 3-42 months. The % sites in this category ranged from 21-35%, depending upon method used to determine probing attachment loss. Widely varying characteristics of sites identified with probing attachment loss were evident for all surface locations and all subgroups of initial probing depth. From a traditional viewpoint, a significant proportion of the losing sites might not have been afflicted with periodonitis. On the other hand, deterioration does not necessarily have to be coupled with obvious inflammation, particularly following therapy.