A 3-YEAR FOLLOW-UP-STUDY OF VARIOUS TYPES OF ORTHODONTIC CANINE-TO-CANINE RETAINERS

The present study was performed to test the tendency for plaque and ca lculus build-up along the wire of different types of bonded orthodonti c canine-to-canine retainers, whether the presence of such retainers c auses any damage to the teeth involved, the failure rate of the retain ers, and any changes in incisor alignment during a 3-year period of re tention. The four test groups received either retainers made of thick plain wire bonded only to the canines (n = 11); thick spiral wire bond ed only to the canines (n = 13), thin, flexible spiral wire bonded to each tooth (n = 11); or removable retainers (n = 14). Accumulation of plaque and calculus along the gingival margin, gingival inflammation a nd probing attachment level were scored in lingual areas from canine t o canine at the time of fixed appliance removal and again 3 years afte r retainer insertion. Incisor irregularity was measured on plaster mod els made at the same time periods. Accumulation of plaque and calculus and development of caries along the wire were scored at follow-up. Re tainer failures were recorded whenever they occurred. The results reve aled no intergroup differences in changes between baseline and follow- up examinations or status along the retainer wire for any of the varia bles. Gingival inflammation and plaque accumulation were scored less f requently after 3 years in retention than at the time of debonding. No signs of caries were seen adjacent to the wire. Failures were observe d of one, four and three of the fixed retainer types, respectively. Th ese patients showed a greater increase in incisor irregularity than th e other patients.