The effect of notching and citric acid on healthy root surfaces in dogs.

Abstract

The purpose of this study was to determine the following on healthy root surfaces: (1) the effect of placement of a notch within dentin on the formation of cementum and/or connective tissue attachment and (2) the effect of citric acid on the notched root surface on the formation of cementum and/or connective tissue attachment. Five young adult dogs were used in the study. Full thickness buccal flaps were reflected on canines, P3, P4, and M1, 4 mm of buccal bone was removed, and the roots carefully planed. One, two, or three parallel notches were placed in the exposed root surface of each tooth. The root surfaces were then treated with either citric acid or saline, and the flaps were replaced and sutured. Animals were sacrificed at intervals of 5 weeks, 9 weeks, 10 weeks, and 12 weeks. Block specimens were examined in step‐serial fashion via light microscopy. The data pool consisted of 19‐matched paired teeth, including 72 roots. Healing responses in a specific notch or on an isthmus varied, including epithelium‐root, connective tissue‐cementum‐root, bone‐connective tissue‐root, ankylosis, or any combination.There was a statistically significant increase in the formation of connective tissue attachment, cementum, and bone toward the apical part of the notches and isthmuses. Epithelium interfaces were significantly higher in notches compared with isthmus surfaces (α= 0.05). The frequency of connective tissue attachment on isthmuses was statistically greater than in notches (α= 0.05). When citric acid was used, in comparison to saline, cementum was observed significantly more often in the coronal portion of the lesions (α= 0.05). This study indicates that citric acid applied to healthy root surfaces in dogs enhances cementum formation in areas farther coronally to the alveolar process than areas treated with saline. Notching per se does not enhance cementum and/or connective tissue attachment. There was no difference in the incidence of ankylosis between saline and citric acid treated specimens.