The effects of citric acid on attachment of laterally positioned flaps

Citric acid demineralization of root surfaces to enhance new attachment clinically appears to be successful, but histologic evidence of new attachment in humans is lacking. Two recession-like defects were surgically created on the facial aspect of mandibular incisors scheduled for extraction in five patients. Each patient had differing degrees of periodontal disease, but the control and experimental teeth of each were similarly involved. The roots were thoroughly planed and an apical reference notch was inscribed just coronal to crestal bone. One tooth served as the control, while the experimental tooth was treated with citric acid (pH 1) for two minutes. Two full-thickness laterally positioned flaps were done to cover the roots. After healing periods of 1, 2, 4, 12, and 20 weeks, the teeth were removed by block section for histologic evaluation. The type of attachment differed on the teeth with longer healing periods. The control teeth exhibited a long epithelial attachment with no evidence of cementogenesis, whereas the experimental teeth had a connective tissue attachment to newly formed cementum coronal to the reference notch. These observations provide evidence that demineralization of root surfaces may promote increased or accelerated connective tissue attachment of laterally positioned flaps.