Résumé
STATEMENT OF PROBLEM: Every effort has been continually made to obtain objectivity in measuring the longevity of fixed restorations, such as by establishing unified judgement standard for deciding success and adopting statistical method that analyzes the data of successful and failed cases at the same time. In Korea, however, desired level of development has not to be made in this field yet. PURPOSE: This study, adopting California Dental Association (CDA) quality evaluation system, established objective standard for deciding success, and inferred the longevity of fixed restorations and their failure analysis through adopting Kaplan-Meier survival analysis. Material and method. In order to assess the longevity of fixed restorations serviced in Korea and causes of failure, a total of 1109 individuals (aged 15-74, 716 women and 393 men loaded with 2551 unit fixed restorations, and 1934 abutments) who lived in Kyung-In Province were examined and the findings were as follows: RESULTS: 1. Length of service of fixed restorations serviced in Korea was 6.86+/-0.15 yr (mean), 5.5 yr (median), and the rate of success was 65.82% in 5 year survival, and 21.15% in 10 year survival. 2. When there was patient's need for replacing old prosthetics, longevity of fixed restorations was 7.51+/-0.27 yr (mean), 7 yr (median), and the rate of success was 61.08% in 5 year survival, and 17.57% in 10 year survival. 3. Longevity of fixed restorations was longest in the over-sixty age group(9.21+/- 0.66) and that of the teen age group(3.39+/-0.28) was shortest (p0.05). 9. Longevity of fixed restorations made of non precious metal was longest (9.60+/-0.40 yr), semi precious and precious trailing behind(p0.05). 11. Longevity of fixed restorations was longest in the centric interference group(9.35+/-0.62) (p<0.05) among different types of occlusal interference. CONCLUSION: We found that longevity of fixed restorations serviced in Korea is affected by age, gender and type of material, and that most frequent cause of failure is defective margin. In order to assess the accurate longevity of fixed restorations, unified research design, overcoming inter-observer difference and establishing the objective research items are needed. Furthermore, it is thought that prospective approach through thorough study and regular follow-ups is needed just from the start of research. Nationwide detailed studies on length of service of fixed restorations manufactured in Korea are hoped to be conducted hereafter.