Pulpal effect of citric acid applied topically to root surfaces

Five beagle dogs were subjected to the raising of full-thickness flaps on the buccal aspects of premolar teeth. Approximately 7 mm. of buccal bone was removed to expose the root surfaces, which were treated with 20 percent citric acid. Saline was used as a control, and after periods of 1, 7, 14, 28, and 56 days, the animals were killed. Specimens were examined histopathologically when microscopic examination failed to detect any pulpal changes in either the experimental or the control specimens.