The purpose of the present clinical study was to evaluate the effect of tooth extractions on the periodontal conditions of adjacent teeth. 40 patients were selected for the study. Prior to the extractions, baseline data of the adjacent teeth were obtained. Plaque (PII) and gingival indices (GI), pocket probing depths and probing attachment levels were scored. In addition, the alveolar bone height was determined radiographically in relation to the CEJ adjacent to the extraction sites. The contralateral side of the jaw, where no tooth had to be removed, was examined as a control. A limited hygienic phase (scaling and root planing of all surfaces examined) was performed immediately prior to the extractions. Using the same parameters, all sites were reexamined 2-4 months and 6-9 months following the extractions. After the hygienic phase, the teeth adjacent to the extraction sites indicated a decrease in the pocket probing depths by 0.5 to 1.5 mm. In shallow pockets (1-3 mm), this decrease was less pronounced than in moderate to deep pockets (4-9 mm), where it was composed of shrinkage of the gingival tissues and gain of probing attachment. The radiographic level of the bony alveolar crest in relation to the CEJ of the adjacent teeth was not altered by the extraction procedure. The oral hygiene performances of the patients were not influenced during the 9-month observation period. Therefore, neither PII nor GI scores showed relevant improvements.(ABSTRACT TRUNCATED AT 250 WORDS)