Aesthetic Efficacy of Resin Infiltration Using Different Conditioning Methods: 24-Month Results
Condition: White Spot Lesion
Study type: Interventional

Summary: 
      Objective: To assess color and fluorescence changes in white spot lesions (WSLs) using
      different surface conditioning methods prior to resin infiltration: 24-months follow-up
      Methods: Thirty patients with each at minimum four WSLs after bracket debonding were
      included. After baseline fluorescence and color measurements, the lesions were randomly
      divided into four groups (n = 30): G1 (control): regular brushing, G2: 15% HCl gel (Icon
      Etch), G3: 37% H3PO4 gel (Scotchbond Etchant), G4: Er:YAG laser (Fotona AT Fidelis III). The
      lesions were desiccated with Icon Dry and then Icon Infiltrant (DMG) was applied. In the
      treatment groups, color and fluorescence were examined at baseline (T0), just after the resin
      infiltration treatment (T1), and after 6 (T2) and 24 months (T3). In the control group, the
      examinations were performed at baseline (T0) and after 6 (T2) and 24 months (T3).
    

Detailed description: 
      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

      After rubber dam placement, the lesions of each patient were randomly divided into 4 groups
      (n = 30):

      G1 (control): The control group received no treatment except regular brushing, G2: 15% HCl
      gel (Icon Etch, DMG, Hamburg, Germany) was applied to the WSLs for 2 min, followed by water
      rinsing and drying with compressed air (each for 30 s).

      G3: 37% H3PO4 gel (Scotchbond Etchant, 3M ESPE, St. Paul, MN, USA) was applied to the WSLs
      for 30 s, which were then water rinsed and dried with compressed air (each for 30 s).

      G4: An Er:YAG laser (Fotona AT Fidelis III, Ljubljana, Slovenia) was applied for 10 s with
      the following operating parameters: energy 300 mJ, frequency 10 Hz, wavelength 2.94 μm, short
      pulses of 10 pulses per second, pulse time 180 ms, distance 1 mm away from lesion, water
      spray cooling 80%.

      The lesions were desiccated with ethanol (Icon Dry, DMG, Hamburg, Germany) and air dried for
      30 s. Then resin infiltrant (Icon Infiltrant, DMG, Hamburg, Germany) was applied to the tooth
      surface and allowed to penetrate for 3 min. A cotton roll was used to wipe excess material
      from the surface, and the material then was light cured for 40 s with an LED device (EliparTM
      S10; 3M ESPE, St. Paul, MN, USA) with 1200 mW/cm2 light intensity in standard continuous
      mode. The clinician repeated the infiltration step for 1 min to infiltrate any remaining
      porosities. Dental floss was used to remove any excess resin from the proximal areas. Then
      polishing was conducted with Sof-Lex disks (3M ESPE, St. Paul, MN, USA) using a slow-speed
      handpiece. The disks were used in a decreasing sequence of granulation and each disk was used
      for 5 s. The same clinician (KAU) conducted all restorative procedures.

      All patients were given oral hygiene instructions and oral hygiene packages, which included a
      toothbrush (Oral B, Advantage Sensitive, P&G Oral Health Care, Mason, OH, USA), fluoride
      toothpaste (Pro-Expert Professional Protection, Ipana, Gross-Gerau, Germany), and dental
      floss (Oral B, Essential floss, P&G Oral Health Care, Mason, OH, USA). The patients were
      asked not to use any other dental products during the study period and the oral hygiene
      packages were renewed every 2 months.

      Follow up examination All patients attended the follow-up visits. New caries formation was
      evaluated during the follow-ups. In the treatment groups the DIAGNOdent Pen and
      spectrophotometer examinations were performed at baseline (T0), just after the resin
      infiltration treatment (T1), and after 6 (T2) and 24 months (T3). In the control group, the
      DIAGNOdent Pen and spectrophotometer examinations were performed at baseline (T0) and after 6
      (T2) and 24 months (T3). Fluorescence and color values were recorded as previously described
      by the same investigator (EK), who was blinded regarding the treatment group allocation of
      the teeth.

      The differences in fluorescence and color values were evaluated by taking into account the
      differences between the initial values and the values at the different evaluation times. L*,
      a*, and b* were measured each time, and the changes in them (ΔL, Δa, and Δb) were calculated.
      The L*-axis indicates how light a sample is (0 is black and 100 is white). The red/green axis
      is represented by the a*-value, with an increase meaning a higher red color component. The
      yellow/blue axis is represented by the b*-value, with an increase meaning higher yellow
      color. The color change ΔE<3.7 is considered a clinically acceptable color difference [9] and
      ΔE for each tooth was calculated as follows:

      ΔE= [(ΔL)2+ (Δa)2+ (Δb)2]1/2 Statistical analysis The normality of the variables was
      evaluated with the Kolmogorov-Smirnov test and the homogeneity of the variances was evaluated
      with the Levene test. Variables were summarized as median [25th-75th percentile] values. In
      the variables that met the parametric test assumptions, the differences between groups and
      within groups were tested with analysis of variance in repeated measurements. The Bonferroni
      test was used for pairwise comparisons. In the variables that did not meet the parametric
      test assumptions, the differences between the groups were determined with the Friedman test
      and the differences between the groups were determined with the Kruskal-Wallis test. In the
      event of a difference, pairwise comparisons were conducted with Dunn's test.
    

Intervention name(s): 15% HCl gel; H3PO4 gel; Er:YAG laser
Intervention type(s): Other; Other; Other
Intervention description(s): Icon , DMG, Hamburg, Germany; Scotchbond Etchant, 3M ESPE, St. Paul, MN, USA; Fotona AT Fidelis III, Ljubljana, Slovenia
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Color stability; Fluorescence; Resin infiltration; White spot lesion