The prognostic value of visually assessing enamel microcracks: Do debonding and adhesive removal contribute to their increase?

Abstract

Objective: To find a correlation between the severity of enamel microcracks (EMCs) and their increase during debonding and residual adhesive removal (RAR). Materials and Methods: Following their examination with scanning electron microscopy (SEM), 90 extracted human premolars were divided into three groups of 30: group 1, teeth having pronounced EMCs (visible with the naked eye under normal room illumination); group 2, teeth showing weak EMCs (not apparent under normal room illumination but visible by SEM); and group 3, a control group. EMCs have been classified into weak and pronounced, based on their visibility. Metal brackets (MB) and ceramic brackets (CB), 15 of each type, were bonded to all the teeth from groups 1 and 2. Debonding was performed with pliers, followed by RAR. The location, length, and width of the longest EMCs were measured using SEM before and after debonding. Results: The mean overall width (W overall ) was higher for pronounced EMCs before and after debonding CB (P , .05), and after the removal of MB. Pronounced EMCs showed greater length values using both types of brackets. After debonding, the increase in W overall of pronounced EMCs was 0.57 mm with MB (P , .05) and 0.30 mm with CB; for weak EMCs, 2 0.32 mm with MB and 0.30 mm with CB. Conclusions: Although the teeth having pronounced EMCs showed higher width and length values, this did not predispose to greater EMCs increase after debonding MB and CB followed by RAR. (Angle Orthod. 2016;86:437-447.)

Enamel microcracks in terms of orthodontic treatment: A novel method for their detection and evaluation

“…Changes for the younger age group were 0.32 µm in the width and 0.22 mm in the length parameters; for the older age group -0.77 µm in the width and 0.02 mm in the length values. The tendency of EMCs to increase during bracket removal can be supported by the literature 9,12) . Applied technique enabled us to evaluate the morphology of the EMC in the cervical, middle, and occlusal third, and locate the same measurement site before and following debonding.…”

“…1. The buccal enamel surfaces of all the teeth included in the study (both from the younger and older age group) were examined employing SEM (TM-1000, Hitachi, Tokyo, Japan) 9,12,13) . The SEM was operated at 15 kV, at ≤5×10 −2 Pa (electron gun vacuum) and at ~30-50 Pa (specimen chamber vacuum).…”

“…From these micrographs vertical height (h) of every tooth's crown was measured. For detailed analysis of EMCs, the buccal tooth surface was divided in three zones of equal height: first zone -cervical third, second zone -middle third, third zone -occlusal third 9,11,12,28) . Following initial examination using SEM, the teeth from the younger and older age groups were divided into four subgroups of 15: subgroup 1, teeth having EMCs; subgroup 2, teeth without EMCs; subgroup 3, teeth showing EMCs, served as a control, and subgroup 4, EMCs free teeth, served as a control.…”

“…EMCs, quite often visible by the naked eye, may jeopardize the integrity of the enamel, cause stain and plaque accumulation on the rough fractured surface, thus increasing susceptibility to carious lesions and compromising the appearance of the teeth [6][7][8] . Studies have shown that the bracket removal procedure is related with the EMCs increase and formation of new EMCs [9][10][11][12][13] . Various methods, such as transillumination, staining, ultrasound, or optical coherence tomography (OCT) have been described in the literature for EMCs detection [14][15][16][17] .…”

Comparative Evaluation of Enamel Micro-cracks Observed before Bonding and after Debonding of Various Types of Ceramic Brackets: A SEM Study

“…14,15 Current information shows that pronounced EMC characteristics (width and length of EMCs) are more when compared with weak EMCs (not visible under normal illumination but visible under SEM). [14][15][16] A modified and economical technique has been introduced recently. This technique 17 claimed to have a better and safe technique for debonding.…”