Background/ Objectives: Clear aligner attachments increase the risk of white spot lesions (WSL), with a 35.5% incidence in adolescents. The number of anterior attachments is an independent risk factor (OR=2.192). Despite 17 million patients treated worldwide, no study has quantitatively assessed demineralization around attachment margins. To compare the effectiveness of CPP-ACP, nano-hydroxyapatite (nHAp), and fluoride varnish versus a control for attachment-associated demineralization using DIAGNOdent monitoring.

Methods: This prospective observational study evaluated 52 patients; 45 were enrolled, and 40 completed after five pre-baseline withdrawals. Participants were allocated to four groups (n=10 each): Group A (control, fluoride toothpaste), Group B (CPP-ACP daily), Group C (nHAp professional + home gel), and Group D (fluoride varnish quarterly). DIAGNOdent measurements were taken around attachments at baseline, 1, 3, and 6 months. Linear mixed-effects models analyzed group differences (p<0.05).

DIAGNOdent Measurement Protocol Calibration and Standardization The DIAGNOdent pen (KaVo, Biberach, Germany) was calibrated before each measurement session according to the manufacturer's instructions using a ceramic standard[18]. A single calibrated examiner performed all measurements to ensure consistency. Intra-examiner reliability was assessed using intraclass correlation coefficient (ICC) with two-way mixed model, absolute agreement, calculated from 30 repeated measurements at 10 randomly selected attachment sites (ICC = 0.85, 95% CI: 0.79-0.91).

Measurement Technique A standardized measurement protocol was employed for all DIAGNOdent assessments. Teeth were air-dried for 5 seconds prior to measurement, and the probe tip was positioned perpendicular to the enamel surface to ensure consistent readings. Four measurements were obtained per attachment site at the mesial, distal, gingival, and occlusal margins. Three measurement passes were performed at each site, with the maximum value recorded to represent the most advanced demineralization present. Measurements were conducted at four timepoints: baseline (T0), 1 month (T1), 3 months (T2), and 6 months (T3).

Inclusion Criteria:

• Age 16-45 years
• Active clear aligner treatment with minimum 6 months remaining
• Presence of ≥10 attachments on anterior teeth and premolars
• Good general health
• Commitment to prescribed aligner wear (20-22 hours/day)

Exclusion Criteria:

• Active carious lesions
• Periodontal disease
• Fluorosis or enamel hypoplasia
• Current fluoride supplement use beyond standard toothpaste
• Pregnancy or lactation
• Systemic conditions affecting salivary flow

The datasets generated and analysed during the current study are available from the corresponding author on reasonable request.

Immediately following publication

Researchers can contact the corresponding author.