Dimensional and angular agreement of LCD printed zirconia nanohybrid orthodontic brackets with CAD targets in a single build in vitro study.

INTRODUCTION

To quantify the within-build agreement of linear dimensions and slot-wall angulation of custom orthodontic brackets fabricated by LCD-masked vat photopolymerization with their nominal computer-aided design (CAD) targets.

METHODS

Fifty brackets were fabricated in one build by one operator using a zirconia nanohybrid photopolymer resin (Rodin Sculpture 2.0). Two examiners measured four outcomes using ImageJ and Geomagic Control X, with three repetitions per examiner and program. Only the 12-reading mean for each specimen and outcome was retained. Means, standard deviations (SDs), confidence intervals (CIs), and conformity with investigator-defined margins (±0.05mm and ±0.35°) were summarized. These margins were not validated clinical thresholds. The brackets were technical replicates of one build; measurement reliability and between-build reproducibility could not be estimated.

RESULTS

The 50 consolidated specimen-level values yielded means (SDs) of 0.557 (0.015) mm for slot height, 0.711 (0.017) mm for slot depth, 0.999 (0.006) mm for base height, and 7.032° (0.174°) for slot-wall angulation. The corresponding 95% CIs were 0.552-0.561mm, 0.706-0.716mm, 0.997-1.000mm, and 6.982°-7.081°. Specimen-level conformity with the investigator-defined limits was 94%, 94%, 100%, and 96%, respectively.

CONCLUSIONS

In this single build completed by one operator, mean linear dimensions and slot-wall angulation were close to the CAD targets. The results describe geometric agreement of averaged measurements within that build; they do not establish measurement reliability, workflow reproducibility, or clinical material suitability.