LONGITUDINAL-STUDY OF PROGNOSTIC FACTORS IN ESTABLISHED PERIODONTITISPATIENTS

Numerous indicators for disease progression have been described in the last decade. The purpose of this study was to examine, longitudinally , a large battery of clinical, microbiological, and immunological indi cators, to try to determine whether the presence of one or a combinati on of these parameters at baseline, would correlate positively with in creased attachment and or bone loss (true prognostic factors). Followi ng initial screening, 79 patients with established periodontitis were monitored longitudinally for one year. Whole mouth clinical measuremen ts, plaque gingival and calculus indices, together with pocket depth a nd attachment level measurements, were repeated every three months. Fu ll mouth radiographic survey, performed at baseline and 12 months, ser ved to determine changes in crestal bone height using an image enhance ment technique. Subgingival plaque samples were taken at baseline and every 3 months. Immunofluorescence assays were performed for the a bat tery of target microorganisms. Serum and GCF samples for IgG subclasse s analysis were obtained at each visit and assayed using ELISA techniq ues. Likewise blood, samples were also drawn at each visit for a quant itative analysis of serum cotinine level. The overall mean attachment loss (AL) and bone loss (BL) were almost identical(0.l59 mm and 0.164 mm, respectively). Individual patients variation was large (-0.733 to + 1.004 mm). An overall 6.89% of sites were active; individual patient s' means ranged from 0-28.9%. Mean pocket depth (PD) showed minimal ch ange over the study period (-0.033 mm) thus suggesting that most if no t all the AL was accompanied by concomitant gingival recession. Smoker s exhibited greater AL and radiographic BL compared to non-smokers. Li kewise, patients' cotinine level showed direct correlation with outcom es of progressive periodontal breakdown. Past severity of periodontal involvement, as reflected in the patients baseline PD, AL and crestal bone height, showed good correlation with longitudinal changes in the periodontium. This correlation was higher for crestal BL as the outcom e variable, while somewhat smaller for change in AL as the outcome var iable. Bacteroides forsythus (Bf.), Prevotella intermedia (Pi.) and Po rphyromonas gingivalis (Pg.) were frequently found in these patients. The presence of these microorganisms at baseline was associated with f urther disease progression. Subjects with mean baseline pocket depth e qual or greater than 3.2 mm were at greater risk for future bone loss 1 year later (O.R. 2.97; C.I. 1.02-8.70). Smokers were at significantl y greater risk for further attachment loss when compared to non-smoker s (O.R. 5.41; C.I. 1.50-19.5). Subjects that harbored B. forsythus at baseline, were at seven times greater risk for increased pocket depth (O.R. 7.84; C.I.1.74-35.3). In conclusion, past periodontal destructio n, smoking habits, BS., Pg., & Pi. are prognostic factors for further periodontal breakdown. When designing clinical trials, or when evaluat ing epidemiological data, it is most important to balance for these fa ctors. Also, treatment strategies should attempt to eliminate or modif y these factors.