Long term effect of chlorhexidine on developing gingivitis in the Beagle dog

Twenty Beagle dogs, ten in an experimental group and ten controls, were given a soft plaque forming diet for 12 months. A .2 per cent aquous solution of chlorhexidine gluconate was applied twice daily to the teeth and gingivae of the experimental animals. The dogs of the control group were similarly treated with saline. Assessments of plaque, calculus and gingivitis were performed after 7, 14, 21, 28 days and 2, 4, 6, 8, 12 months. Gingival exudate was also measured. During a period of six months topical application of .2 per cent chlorhexidine essentially prevented plaque, calculus and gingivitis development, while control dogs exhibited large amounts of dental deposits and marked clinical signs of chronic gingivitis. After six months, however, plaque and gingivitis appeared also in the chlorhexidine group. At the termination of the experiment. Gingival Index and exudate scores of the chlorhexidine group had reached approximately half the values of the saline group. No clinical side effects but the occurrence of stain on teeth was registered during the entire experiment.