Endotoxin levels in subgingival plaque and saliva in patients prior to and following fixed orthodontic appliances : a preliminary clinical study

Abstract

It has been demonstrated that endotoxin plays a role in the destructive changes seen in periodontal disease. The purpose of this study was to quantify the levels of detectable endotoxins in subgingival plaque and saliva, before and after wearing fixed orthodontic appliances; to study: 1) if endotoxin production occured to any appreciable extent owning to mechanical capture of oral microflora and the development of plaque in orthodontic appliances, 2) the relationship of endotoxin to the proportion of gram-negative and gram-positive microorganisms and to the frequency of gingivitis found during an orthodontic treatment. A comparable clinical study was done before and one month after the placement of fixed orthodontic appliances in patients between 16-25 year old, undergoing orthodontic therapy. Clinical (plaque index, gingival index, and pocket depth) and microbiological data were recorded for the maxillary left central incisor, maxillary right first molar, mandibular right central incisor and mandibular left first molar. Comparisons included before and after assessments of gingival inflammation, plaque index, pocket depth, plaque weight, and ratio of Gram-negative and Gram-positive bacteria and levels of endotoxins in plaque and in saliva. Within the limits of this study it can be concluded that: - Although one month after the placement of fixed orthodontic appliances, the plaque index, the gingival index and the plaque weight, showed significant increases, no differences were found in pocket depth, the ratio of Gram-negative and Gram-positive microorganisms, and in the levels of endotoxins in plaque. - In saliva, despite the small sample, the gram-stain showed a significant predominance of Gram-positive bacteria, but the endotoxin levels did not increase after appliances were placed. However, it should be noted that in none of the patients the endotoxin levels increased. -The flora and the environment one month after the placement of the appliances seemed to be compatible with health. However, this is a very early stage of the orthodontic therapy and it would be interesting and necessary to do a longitudinal study involving at least 6 months of the treatment. - These findings imply that the presence of fixed orthodontic appliances, per se, need not contribute to periodontal disease; the orthodontist should take advantage of this observation by emphasizing the importance of prophylactic programs for patient undergoing orthodontic treatment.