Effect of tetracycline and/or scaling on human periodontal disease

Abstract Twelve adult patients with severe chronic periodontitis were examined prior to treatment, and after 8 and 25 weeks following tbe start of treatment. Six subjects received tetracycline during weeks 1 and 2 and weeks 7 and 8, while the other six did not. All subjects were instructed in oral hygiene and received a series of scaling and root planing treatments on one side only of their dentition. The contralateral side received no scalings at any time. The experiment was designed to provide clinical and microbiological data at the 0‐, 8‐ and 25‐week intervals for at least six sites in each of four groups, namely untreated sites (T 0 S 0 ), sites which were scaled only (T 0 S 1 ), sites which received tetracycline only (T 1 S 0 ) and sites which were scaled and were exposed to tetracycline (T 1 S 1 ). In addition, biopsies of initially diseased sites which had been treated or left untreated were evaluated by light and electron microscopy at all time intervals. The results indicated that T 0 S 0 sites remained more or less unchanged with respect to all parameters during the 25‐week period, with the exception of a decrease in PII scores due to improved oral hygiene. T 0 S 1 sites showed a marked clinical improvement between time 0 and 8 weeks, i.e. reduced PII and GI scores and reduced probing depth; the microbial flora showed an increase in the proportion of coccoid cells with a concomitant decrease in motile rods and spirochetes; the plasma cell‐dominated infiltrated connective tissue (ICT) showed a significant decrease in the proportion of plasma cells with a corresponding increase in lymphocytes; evidence of collagen deposition was also observed histologically. This 8‐week status persisted after 25 weeks, but in addition the tissues showed an increase in the proportion of fibrobiasts and a decrease in the proportion of lymphoblasts. T 1 S 0 sites showed a similar improvement in the clinical and microbiological parameters at 8 weeks, but tbe ICT showed only a moderate reduction in the proportion of dead and unidentified cells. After 25 weeks, tbe clinical parameters remained unchanged from the 8‐week interval, but the microbial composition and the tissue characteristics showed a significant rebound toward the values observed at baseline. T 1 S 1 sites showed essentially similar changes in the clinical, microbiological and tissue characteristics as the T 0 S 1 sites for all time intervals. However, in the presence of the antibiotic the 8‐week proportions of coccoid cells were higher and those for motile rods and spirocbetes lower. Evaluation of all biopsied sites revealed a positive correlation between the proportion of plasma cells in the ICT and the proportion of spirochetes in the associated microflora. The results suggest that the microflora of healthy and periodontally diseased sites differ and that some of these differences are associated with detectable differences in the composition of the ICT. Mechanical debridement and/or treatment with tetracycline cause changes in the clinical, microbiological and histological parameters. Discontinuation of treatment with tetracycline leads to a return of the microbial and histological parameters toward values observed prior to treatment. These changes appear prior to detectable clinical changes.