Value of some laboratory and clinical measurements in the treatment plan for advanced periodontitis.

In our previous study, we reported that only 13 of 46 adult patients with advanced periodontitis responded well to initial non-surgical periodontal therapy. In the present follow-up study, the remaining 33 patients were randomly treated further using either modified Widman flap surgery or systemic metronidazole. The patients responding unsatisfactorily to this 2nd treatment phase, received supplementary systemic chemotherapy or surgery, respectively. By using this study design, we determined which baseline clinical variables and/or laboratory findings predicted the treatment outcome in these study patients. Clinical variables included the assessment of bleeding, suppuration, probing pocket depth, furcation lesions, relative attachment level and radiographic infrabony defects. Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis were cultured from subgingival plaque samples. The specific IgG and IgA antibody levels against 5 serotypes of A. actinomycetemcomitans were determined in serum and saliva. Elastase-like, trypsin-like and general protease activities were assessed from saliva. The bivariate statistical analyses showed that the most pronounced difference between the patients responding well to initial non-surgical therapy (group MC, n = 13), to either supplementary surgery or chemotherapy (group FT1, n = 11), or those responding to the complex therapy (group FT2, n = 17), was the prior extent of periodontal destruction expressed as the proportion of > or = 6 mm deep periodontal pockets. When multiple linear regression was used to investigate the influence of clinical and laboratory findings on the variation of treatment response between the 3 groups, the most significant explanatory factor was the simultaneous presence of subgingival A. actinomycetemcomitans and multiple deep periodontal pockets. None of the immunological or biochemical variables used had any further influence in the model. Pretreatment microbiological examination, especially for the detection of A. actinomycetemcomitans, seems to be a valuable laboratory screening method for identifying complex treatment need in adult patients with advanced periodontitis. However, the evaluation of the extent and pattern of periodontal breakdown remains crucial for choosing the treatment strategy including surgery and/or chemotherapy in A. actinomycetemcomitans-infected adult periodontitis patients.