Multiple Abfractions. The wedge-shaped defects are located at the vestibular tooth neck in most cases and have a sharp edge. An excentrical excess stress is the discussed cause for these lesions (BRAEM et al., 1992; HEYMANN et al., 1991). This excessive stress compresses the tooth in the tooth neck region, resulting in micro-fractures of the enamel and dentin. Further stress presumably leads to fragments of the tooth hard substance breaking off (LEE und EAKLE, 1996; GOEL et al., 1991).
