Healing events following nonsurgical periodontal therapy in patients with periodontal pockets up to 12 mm deep were investigated. Incisors, cuspids and premolars in 16 patients were treated by plaque control and supra- and subgingival debridement using hand or ultrasonic instruments in a split mouth approach. The results were evaluated by recording of plaque scores, bleeding on probing, probing pocket depths and probing attachment levels. Minimal change in gingival conditions occurred during the initial 3 months of experimentation, which were utilized for plaque control measures alone. Subsequent to instrumentation and during the following 9-month period, a gradual and marked improvement of periodontal conditions took place. During the remaining 12 months of the 24-month experimental period no further changes of the recorded parameters were noted. No differences in results could be observed when comparing hand versus ultrasonic instrumentation, or when comparing the results of 2 different operators. Initially, a total of 305 sites demonstrated probing pocket depths greater than or equal to 7 mm. At the 24-month examination 43 such sites remained. The results indicate that there is no certain magnitude of initial probing pocket depth where nonsurgical periodontal therapy is no longer effective.

Healing events after nonsurgical periodontal therapy in patients with periodontal pockets 4--7 mm deep were investigated. Incisors, cuspids and premolars in 15 patients were treated by plaque control and supra- and subgingival debridement using hand or ultrasonic instruments in a split mouth approach. The results were evaluated by recordings of plaque scores, bleeding on probing, probing pocket depths and probing attachment levels. All these parameters were improved during the initial 4--5 months after start of therapy. Little change occurred during the rest of the 13-month observation period. No difference of results could be observed comparing hand and ultrasonic instrumentation or comparing the results of two different operators. Initially a total of 106 sites demonstrated probing pocket depths greater than or equal to 6 mm. At 13 months only 13 such sites were observed. The apparently successful results of conservative treatment of patients with 4--7 mm deep pockets in the present study raise the question to what extent nonsurgical therapy is feasible also in patients with severely advanced lesions.

The reproducibility of probing attachment level measurements in incisors, cuspids and premolars was studied in 2 groups of patients with severely advanced periodontal disease. The results showed that approximately 90% of the recordings could be reproduced within within +/- 1.0 mm difference. This was found for intra-examiner as well as inter-examiner comparisons of 2 examiners. Measurements using onlay margins for reference point demonstrated somewhat less variability than the use of cemento-enamel junction for reference. The level of reproducibility varied notably between patients and was improved following non-surgical periodontal therapy. Also, the reproducibility varied significantly between tooth types, tooth surfaces and probing pocket depths. It was concluded that in clinical studies, the evaluation of the healing response of individual lesions should include consideration of the variability of repeated measurements for each of the investigated tooth sites.

The purpose of the present study was to determine the diagnostic value of clinical scores of supragingival plaque, bleeding, suppuration and probing depth to predict probing attachment loss in patients on maintenance following nonsurgical periodontal therapy. Non-molar teeth in 39 subjects were monitored and the above scores were repeatedly obtained throughout 5 years of observation following initial treatment. Probing attachment loss between 0-60 months was determined by a combination of linear regression analysis and end-point analysis. The results revealed that all the investigated scores were associated with probing attachment loss. This association was demonstrated by improved diagnostic predictability along with increased frequency or magnitude of the various scores. Also, the diagnostic predictability improved with increase in length of time for recording of the scores. The diagnostic predictability of either accumulated plaque scores and accumulated bleeding scores reached a maximum of about 30%. Residual probing depth greater than or equal to 7 mm reached a predictability of around 50% and increase in probing depth greater than or equal to 1.0 mm reached about 80% after 60 months. Thus, of the clinical scores investigated, increase in probing depth was found to be most valuable in predicting probing attachment loss.