[Clinical evaluation of 20K gold alloy inlay restorations on young permanent teeth from the viewpoint of tooth-emergence age].

UNLABELLED: We observed 173 cases of 20K gold alloy inlay restorations on young permanent premolars and molars and investigated the emergence age of all these teeth. The observation period of inlay restorations was from 1 year to 11 years and 6 months. Clinical evaluations were made by exploring with an explorer, roentgenography and color photography. RESULTS: 1. Changes in inlay restorations occurred in 1 case (0.6%) of discoloration and 4 cases (2.3%) of inlay dislodgement. 2. Changes in teeth occurred in 8 cases (4.6%) of secondary caries, 15 cases (8.7%) of new caries and 4 cases (2.3%) of pulpitis. 3. Clinical failures occurred in 32 cases, and 24 of those cases were restored within 2 years after tooth emergence. 4. Almost clinical failures occurred on the maxillary and mandibular first molars. 5. In 27 cases (15.6%), repeat restoration was necessary. In 10 of these cases, the original 20K gold alloy inlay restorations continued in use.