Aesthetic Efficacy of Resin Infiltration Using Different Conditioning Methods: 24-Month Results

Prior to the study an experienced investigator (EK) attended a training and calibration session (k value = 0.88) and evaluated the severity of WSLs under direct illumination using a dental lamp with the aid of a standard 3.0× loupe (Keeler, Windsor, UK). Isolation was achieved with a cotton roll and suction. For the visual severity evaluation, all teeth were cleaned and air dried for 5 s and each lesion was scored according to ICDAS II free smooth-surface criteria [20]. Lesions with code 1 (first visual change after prolonged air drying) and code 2 (distinct visual changes without air drying) were included. The teeth were cleaned with a rubber cup and pumice, rinsed, and air dried (each for 30 s).

The same investigator (EK) used a DIAGNOdent Pen 2190 (Kavo, Biberach, Germany) to score each lesion afterwards. Before every scoring session, the device was calibrated using the standard ceramic according to the manufacturer's instructions. The teeth were rinsed and air dried before registration and a type B probe tip was positioned on the buccal surface of the tooth and rotated around its vertical axis until the peak reading was displayed on the panel. All measurements were taken 3 times and the average fluorescence value was recorded.

Out of 40 consecutive patients between 14 and 21 years of age who had just finished their fixed orthodontic treatment, 4 patients declined to participate in the trial and 6 patients did not meet the inclusion criteria, and 30 patients (18 females, 12 males, aged 15-19 years, mean age 17.1 years) with at least four WSLs on the buccal surfaces after bracket debonding were included in the trial. Patients with any systemic disease, bad oral hygiene, a smoking habit, enamel hypoplasia, staining, fluorosis, or restoration or cavity in any teeth with WSLs were excluded from the study. At the end of the clinical examination a total of 120 non-cavitated, unrestored WSLs after multibracket treatment on the buccal surfaces of the anterior and premolar teeth in the upper and lower jaws of 30 patients were included.

A spectrophotometer (SpectroShade; Medical High Technologies, Italy) was used to measure color parameters in the same examination room with standardized light conditions. The spectrophotometer was calibrated before the measurements of each specimen using a standard white background. The mouth piece attached to the intraoral camera of the spectrophotometer was placed at 90° on the alveolar process above each tooth. After correct placement of the optic handpiece, the examiner checked that the tooth appeared in the center of the yellow target box on the computer screen, and the opposing teeth, the tongue, and lips were not visible on the screen. The results from each tooth obtained by spectrophotometer were recorded, with the mean values of L*, a*, and b* automatically calculated at three consecutive times by positioning the intraoral camera, removing it, and then repositioning it. Three consecutive readings were taken using the spectrophotometer and the mean values were recorded.

Treatment