Evaluation of surface roughness and microhardness of enamel white spot lesions treated by resin infiltration technique (icons): An in-vitro study

Objectives This research was designed to evaluate the effect of resin infiltration material (Icon) and remineralizing agents (n-HA, CPP-ACP) on micro hardness and surface roughness of enamel white spot lesion. Materials & Methods 120 sound non carious human anterior teeth were used in this study. The teeth were divided according to the test of evaluation into two main groups. Group H: for assessment of micro hardness and group R: for assessment of surface roughness (60 teeth each).Then each group was divided into four equal subgroups (15 teeth each) according to the treatments applied as follows: subgroup(C): control, subgroup (P): CPPACP, subgroup (I): Icon and subgroup (N): n-HA. Each subgroup was further subdivided into three equal divisions (5 teeth each) according to the storage times in artificial saliva; one week (S1), four weeks (S2) and eight weeks (S3). The crowns of all teeth were separated from the roots and embedded horizontally in middle of the mould leaving the labial surface projecting using self-curing acrylic resin. Al specimens were immersed in demenaralizing solution for artificial enamel white spot lesion formation. Then treated with each respective material as follow: In subgroup (I) Icons was applied on labial surface of specimens and then immersed in artificial saliva. In subgroup (P) the labial surfaces of specimens were brushed manually by a soft toothbrush and with gentle pressure; brushing procedures were carried out three times daily with CPP–ACP- containing paste for 3 minutes then immersed in artificial saliva. In subgroup (N) specimens were immersed in 10% n-HA solution for 3min then immersed in artificial saliva and these applications were repeated daily. While subgroup (C) did not receive any surface treatment, but it immersed in artificial saliva as a positive control subgroup, artificial saliva was changed daily. For assessment of microhardness and surface roughness the enamel white spot lesion specimens in the four different subgroups were examined three times (after one week, four weeks and eight weeks from the first time of treatment application) by Vickers micro hardness testing machine and none contact profilometer. Results The results of microhardness revealed that the subgroup (N) was provided the highest micro hardness mean value, followed by subgroup (I) group, then subgroup (P) group while subgroup (C) showed the lowest micro hardness mean value.The results of surface roughness revealed that the subgroup (P) group was provided the highest surface roughness mean value, followed by subgroup (C), then subgroup (N) while subgroup (I) showed the lowest surface roughness. Conclusions Resin infiltration material (Icon) had a positive effect on microhardness and surface roughness of enamel white spot lesion.