Evaluation of demineralisation adjacent to bracket bonded with conventional orthodontic composite, resin modified GIC and nano-ceramic restorative composite

Abstract

ContextWhite spot lesions form within 4 weeks of bracket placement and 96% patients show its prevalence during fixed treatment. Less than optimal esthetic result is achieved after orthodontic treatment due to demineralization of enamel adjacent to fixed orthodontic appliances in patients with inadequate oral hygiene. AimsAn invitro evaluation of areas of demineralization, before and after subjecting the teeth to caries producing solution for 30 days for three adhesive resins, Transbond XT†, Fuji-Ortho-LC ▪ and Filtek Z 350♦. Settings and design180 sound premolars were divided into 2 broad groups of 90 each. Control group were exposed to artificial saliva solution for 30 days, whereas, experimental group were exposed to both artificial saliva (for 11h) and caries producing solution (for 1h) at the rate of 2 cycles per day for a period of 30 days. These groups were further subdivided into six subgroups of 30 teeth each. After 30 days, for both groups, teeth cusps were ground flat and longitudinal bucco-lingual sections were made with a series 1000 Deluxe Hard tissue microtome, photographed under polarized light microscopy and Motic Image plus software 3.2 was used to measure amount and depth of demineralisation. Depth of demineralization lesion was obtained as an average from three sites within the lesion (gingival, middle and occlusal). ResultsAnalysis of variance (two-way ANOVA) and Tukey's HSD post hoc test indicated significant differences among these groups and materials. Teeth bonded with conventional composite (Transbond XT™† 3M), nanofilled restorative material (Filtek Z 350™♦ 3M) showed more lesion depth when compared with RMGI cement (Fuji-Ortho-LC™ ▪). RMGIC groups had smaller mean lesion depths when compared with composite resin groups. Materials from experimental group showed increased depth of demineralization (p<0.0000) when compared with control group. ConclusionsArea of demineralization in experimental group increased significantly when compared with control group. Least amount of demineralization was seen with RMGIC (Fuji-Ortho-LC ▪) and highest with conventional orthodontic composite (Transbond XT†).