Abstract
Objectives White spot lesions (WSLs) are a complication of orthodontic therapy. This study investigated the effect of MI
(minimally invasive) Paste Plus (MIPP) and MI Varnish (MIV) on WSLs in orthodontic patients during a 12-month, randomized,
single-blind, prospective, standard-of-care controlled clinical trial.
Materials and methods Forty subjects, recruited from the UCSF School of Dentistry Orthodontics Clinic, were randomly
assigned to the experimental (twice-daily 1100 ppm fluoride toothpaste, daily MIPP, quarterly MIV application) or control group
(twice-daily 1100 ppm fluoride toothpaste, fluoride rinse recommendation). Facial surfaces of incisors, canines, and first bicus-
pids were evaluated at baseline, 3, 6, and 12 months using the enamel decalcification index (EDI) and the international caries
detection and assessment system (ICDAS).
Results Findings from 37 subjects are reported. At 12 months, teeth receiving experimental treatment were at lower but not
significantly different odds of increased EDI scores (odds ratio, OR 0.63; intra-patient cluster-adjusted 95% CI 0.43, 1.18) and
not associated with increased ICDAS scores (OR 0.99; 95% CI 0.64, 1.54). There was no statistically significant difference in
mean patient-level EDI sum (experimental group 40.2; control 41.3; t test p = 0.80), ICDAS score (experimental 22.3; control
22.6; Mann-Whitney U test p = 0.80), or percentage of scored surfaces with ICDAS > 0 (experimental 54.6%; control 55.2%; t
test p = 0.88). Salivary fluoride levels were significantly higher at 12 months for the experimental than for the control group (0.20
± 0.26 versus 0.04 ± 0.04 ppm, Mann-Whitney U test p < 0.01).
Conclusions Applying daily MIPP and quarterly MIV resulted in no statistically significant differences in EDI sum and ICDAS
scores. Higher salivary fluoride levels in the experimental group suggest that MIPP and MIV effectively deliver fluoride when
used clinically.
Clinical relevance Daily MIPP and quarterly MIVapplications do not appear to reduce significantly WSLs incidence during fixed
orthodontic treatment.