The authors describe a study in which they placed 126 Class V composite resin restorations without mechanical retention, divided into three groups of 42, in 23 patients. They followed the performance of the restorations over a three-year period. For all three groups, restorations were placed using All-Bond 2 dental adhesive and Z100 composite resin; A.R.T. Bond and Brilliant Dentin composite; and Prisma Universal Bond 3 and Variglass VLC polyacid-modified composite resin. The authors evaluated retention as well as color stability, wear resistance, sensitivity, sulcular depth, loss of attachment, bleeding on probing and crevicular fluid flow. Based on their results, the authors propose that restoration of Class V lesions without using mechanical retention could be expected to succeed in seven of 10 restorations over a three-year period using these restorative systems.