Microleakage between composite-wire and composite-enamel interfaces of flexible spiral wire retainers. Part 1: comparison of three composites.
The aim of this investigation was to test the hypothesis that there is no difference in microleakage between composite-enamel and composite-wire interfaces, when different composites are used. Forty-five freshly extracted human mandibular incisors separated into three groups were used in the study. Multi-stranded 0.0215 inch diameter wire was bonded to enamel using two conventional (Transbond XT and Transbond LR) and a flowable (Venus Flow) orthodontic composite. The specimens were sealed with nail varnish, stained with 0.5 per cent basic fuchsine for 24 hours, sectioned and examined under a stereomicroscope, and scored for microleakage at the composite-enamel and composite-wire interfaces from the mesial and distal margins. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U-tests with a Bonferroni correction. Little or no microleakage was observed between the composite-enamel interfaces for the three investigated composites, and any difference was not statistically significant. However, statistically significant differences were found between microleakage at the composite-wire interface for both the conventional and flowable composite groups (P < 0.001). Flowable composite showed the highest leakage (mean: 4.8 +/- 0.8 mm), while Transbond XT (mean: 0.5 +/- 0.3 mm) and Transbond LR (mean: 1.1 +/- 1.2 mm) showed significantly lower and comparable results. The amount of microleakage at the wire-composite interface was significantly greater than that at the enamel-composite interface of flexible spiral wire retainers (FSWRs). The null hypothesis is therefore rejected. Flowable composites may not be appropriate for bonding FSWRs.
Department of Orthodontics, University of Erciyes, Turkey.
Tancan
T
Uysal
Asli
A
Baysal
Serdar
S
Usumez
Mustafa
M
Ulker
D003188:Composite Resins / Q000009:adverse effects; D001840:Dental Bonding / Q000009:adverse effects; D003743:Dental Enamel; D003763:Dental Leakage / Q000209:etiology; D006801:Humans; D007180:Incisor; D008422:Materials Testing; D016382:Orthodontic Appliance Design; D018704:Orthodontic Retainers / Q000009:adverse effects; D009969:Orthodontic Wires / Q000009:adverse effects; D019279:Resin Cements / Q000009:adverse effects / Q000737:chemistry
D003188:Composite Resins; D019279:Resin Cements; C481385:Transbond LR; C477790:Transbond XT; C542517:Venus flow composite resin