CLINICAL COMPARISON BETWEEN A GLASS-IONOMER CEMENT AND A COMPOSITE FOR DIRECT BONDING OF ORTHODONTIC BRACKETS

The clinical performance of a glass ionomer cement for direct bonding of orthodontic brackets was compared with a composite resin routinely used in this procedure. Brackets were bonded, using both materials, in alternate quadrants of 16 patients of the Orthodontic Clinic of the S tate University of Rio de Janeiro. A total of 225 teeth, 112 in the gl ass ionomer cement group and 113 in the composite group, were tested. Bond failure frequencies were recorded for 12 months, and chi-square s tatistical test was carried out comparing the failure rates of the mat erials, The composite showed a statistically significant lower failure rate (7.96%) than the glass ionomer cement (50.89%), regardless of th e dental arch tested. Although the glass ionomer cement presents impor tant properties not observed in the composite, it is necessary to incr ease its cohesive strength to permit its clinical use for direct bondi ng of orthodontic brackets.