Cervical enamel crazing lines were counted after preparing MODBL preparations in freshly extracted maxillary premolars. The teeth were restored with composite onlays. One-third of the restored teeth were left as is. In the second third MD intra-composite staples were prepared. The staples were prepared at 10, 20 and 30 minutes and 24-hour intervals. The craze lines were counted pre- and post-restoratively. Intra-composite staples reduced craze lines substantially. There were no statistical differences between MD and MD-BL staples. Thirty minutes proved to be the maximum time to prepare these staples to have a reducing effect on the number of craze lines.