[Investigated reports of tooth fractures cases from November, 1986 to September, 1988].

Researching the actual condition of tooth fractures, clinical records and X-ray photographs of 2717 patients, visited P.D.I. Dental Clinic from November, 1986 to September, 1988 were investigated statistically. 174 cases were tooth fractures in 2717 patients. The frequency rate of tooth fractures at an early age was low, increased from the latter half of the 30s and was highest at the latter half of the 50s accounted for over 10%, and decreased from the 60s. In the upper anterior teeth, the crown fractures caused by traumatic factors, at an early age showed a high proportion, and in the lower anterior the tooth fractures were rare. In the posterior the root fractures of non-vital teeth attributed to dental treatment at the middle and advanced age indicated a high proportion. In the case of tooth restored with metalcore and bridge, the proportion of the root fractures were high, the metalcore, was used in 63%, and in the bridge in 27% of the root fractures.