Colour stability of resin infiltrant (icon©) following pretreatment in white spot lesion of multiple lesion depths: an In-vitro study

Abstract

Resin infiltration (RI) is a low-viscosity resin used for minimally invasive treatment for the treatment of white spot lesion. RI can mask the opacities of the enamel by penetrating the lesion through capillary action. Major disadvantage of RI is the susceptibility to staining over time due to the presence of chromogenic agents present in our diet. The primary aim of this study is to evaluate the colour stability of resin infiltrant (ICON©) following pre-treatment procedures at different levels of lesion severity in WSL, and the secondary outcome is to investigate the maximum penetration depth of resin infiltrant following pre-treatment procedures. Extracted human premolars (n=195) with different WSL depths (A=100μm; B=180μm; C=200μm) were divided into three groups of 65 teeth each. In each group, 13 specimens were allocated into five interventions: control – no treatment (NT), RI only (R), microabrasion pre-treatment procedure and RI (M), fluoride pre-treatment procedure and RI (F) and 240 seconds of ICON Etch© as pre-treatment procedure and RI (E). In each intervention, one specimen was sectioned and assessed for the maximum depth of penetration of resin infiltrant. Four specimens per group were subjected to three staining agents (saline, coffee, and turmeric). Colour changes were assess at three time points: baseline (T0), after 24 hours (T1) and after 6 months (T2). Groups A-E and B-E showed the highest penetration of resin infiltrant (ICON©). In Group C, the highest penetration was found in group C-F. Group A-E showed a significant decrease in colour change in coffee staining from 24 hours to 6 months (mean difference (95% CI): 7.47 (3.258, 11.687), p<0.05) which was similar in Group C-E (mean difference (95% CI): 5.96 (1.781, 10.144), p<0.05). Turmeric staining showed the greatest colour changes irrespective of lesion depth and pre-treatment provided. In conclusion, increasing the etching time as pre-treatment had the best colour stability of resin infiltrant (ICON©) for lesion depth of 100 and 210μm.