A longitudinal study of crevicular fluid in periodontal disease in beagles

A longitudinal study on the composition of crevicular fluid (CF) and serum was carried out in seven beagle dogs during a period from health to 16 weeks of gingivitis and then 8–10 weeks of ligature induced periodontitis (LIPD). The fluids were collected at weekly intervals and the pH and the concentrations of Ca, Mg, Na, and K and the protein profile were determined. Also at weekly intervals, the plaque index, gingival index, calculus index, and pocket depth and attachment loss were recorded for the teeth from which crevicular fluid was collected. Radiographs were taken on the 0 day and after the dogs were sacrificed. Histopathological studies were carried out following sacrifice of the dogs, and the distances between the cemento‐enamel junction and the coronal end of the junctional epithelium and the cemento‐enamel junction and the crest of the alveolar bone were measured. A two‐way ANOVA analysis of the two fluids (CF and serum) and of the two diseases (gingivitis and periodontitis) showed significant differences between the two fluids and between the two diseases. Further statistical analysis showed that in serum none of the constituents studied differed significantly between gingivitis and LIPD, but a significant rise in the concentrations of Ca, Mg, and K was observed in CF during LIPD. The pH of CF was significantly lower during LIPD, but no significant change was observed in the concentration of Na ion. An apparent relationship was observed only between the concentration of K ion in CF and the attachment loss during LIPD. The serum protein profile remained unchanged throughout the period of this study. During gingivitis the CF protein profile was identical to that of serum, but during LIPD a new protein peak appeared. This material had a molecular weight of < 200,000 daltons. Histopathological and radiographic analysis showed bone loss in all but one dog during LIPD. Histopathological study also showed no significant difference in the distance between CEJ and the coronal end of the junctional epithelium between the ligated and the non‐ligated sides. This study showed that in beagle dogs the CF differed significantly from that of serum. Also, LIPD caused significant changes in both ionic concentrations and protein profile of crevicular fluid.