Background, aims: In order to investigate the r le of various putative clinical and microbiological risk markers, a longitudinal study was initiated in a young population deprived of regular dental care. In 1987 all inhabitants in the age range 15-25 years living in a village with approximately 2,000 inhabitants at a tea estate on Western Java, Indonesia, were examined clinically and microbiologically. In total, 167 subjects of the original group of 255 adolescents were re-examined in 1994. The material presented in this paper describes the clinical periodontal condition at baseline (1987) and at follow-up (1994), 7 years later. Furthermore, the relationship between progression of the disease and baseline clinical and microbiological data was assessed.
Methods: Plaque index (PI), bleeding on probing (BOP), pocket depth (PD), and attachment loss (AL) were scored at the approximal surfaces of the vestibular aspects of all teeth. The number of approximal surfaces of the Ramfjord teeth showing subgingival calculus was recorded. At baseline, the dorsum of the tongue, the buccal gingiva in the upper jaw, the saliva and the deepest bleeding pocket without clinical loss of attachment were sampled for microbiological examination with phase contrast microscopy and indirect immunofluorescence.
Results: Mean values at baseline and at follow-up were PI: 1.01 and 1.15, BOP: 0.80 and 1.16, PD 3.26 mm and 3.32 mm, AL: 0.33 mm and 0.73 mm, respectively. All parameters except PD showed a statistically significant increase over the 7-year period. The prevalence of the studied bacteria irrespective of the sample site was: A. actinomycetemcomitans 53%, P. gingivalis 88%, P. intermedia 100%, spirochetes 89% and motile micro-organisms 100%. At the full mouth level, logistic regression showed significant odds ratios for progressive disease with age (1.15), subgingival calculus (1.20) and subgingival presence of A. actinomycetemcomitans (4.61). Presence of any of the selected micro-organisms on the mucous membranes was not related with progressive disease. In order to study local factors to explain local disease activity, each subject was characterized using the sampled pocket, which was the deepest bleeding pocket without LA at baseline, as a single response site per patient. In this constrained design, the main statistical factors associated with progressive disease were presence of motile micro-organisms and the plaque score.
Conclusions: This study identified 3 main risk markers for disease progression at the full mouth level: age, amount of subgingival calculus and subgingival presence of A. actinomycetemcomitans.