Studies of host responses during experimental gingivitis in humans

Abstract

The aim of the study was to find out whether autologous supragingival plaques collected at various times during the development of experimental gingivitis in men differ in their potential to induce PMN responses in vitro. Ten subjects refrained from all oral hygiene for a period of 21 days. At day 0, Day 3 and Day 21 after cressation of oral hygiene clinical indices (plaque index, gingival index, gingival crevicular fluid flow) were assessed plaque was collected at day 3 and Day 21 after cessation of Oral hygiene clinical indices (plaque index, gingival index, gingival crevicular fluid flow) were assessed plaque was collected at Day 3 and Day 21. PMNs, isolated from peripheral blood 1–2 months after the non‐brushing period were incubated with the various autologous plaques in the presence or the absence of autologous serum. Supernatants of cell cultures were monitored for extracellular release of lysosomal constituents, viz. lysozyme, myeloperoxidase and lactoferrin. There was no difference in the amounts of lysozyme, myeloperox dase and lactoferrin. There was no difference in the amounts of lysozyme or myeloperoxidase released by PMNs. The inclusion of fresh serum enhanced PMN release reactions but there was no significant differences in the relative capacity of Day 0, Day3 and Day 21 sera to modulate PMN responses. A statistically significant positive correlation was established betwen the magnitude of lactoferrin release from PMNs exposed to Day 3 plaque and the gingival fluid flow recorded on Day3. Lactoferrin is segregated in the specific granules of the PMNs which also contain other cationic proteins, collagenases and neutral proteinases. These data suggest that a possible causal relationship may exit between the release of PMN constituents and the development of inflammation during the early phases of gingivitis.