Effect of chlorhexidine on gingival wound healing in the dog. A histometric study

Wound healing after gingivectomy was studied in five 1-year-old dogs (Beagles). During a preparatory period of 4 months, the teeth of the dogs were brushed twice a day using a toothbrush and dentifrice. At the end of this period, all gingival units appeared healthy. All mechanical tooth cleaning procedures were then terminated. Following a period a 2 weeks without oral hygiene, six gingival units, taken bilaterally from the maxillary first molar and posterior premolar areas, were subjected to standardized gingivectomies. Subsequently, the biopsied areas of the left half of the jaws were treated twice a day with a 0.2% aqueous solution of chlorhexidine digluconate for 42 days, while corresponding areas of the right jaws were given saline treatment. Tissue specimens were obtained after healing periods of 42, 28, 14, 7, 4 and 2 days. They were then immediately placed in a Karnovsky fixative, and afterwards decalcified in EDTA. The rate of tissue regeneration and degree of inflammatory cell infiltration were evaluated with histometric methods. It was found that while gingival wounds treated with saline regenerated with extensive inflammatory reactions, corresponding chlorhexidine-treated wounds healed with only minor signs of inflammation.