Impact of different levels of diastema and crowding on the precision of 3D-printed dental models: a comparative analysis using digital superimposition

ABSTRACT Introduction: This study aimed to evaluate the impact of varying degrees of anterior diastema and crowding on the precision of 3D-printed dental models using digital superimposition techniques. Materials and Methods: A digital maxillary arch model was modified in the anterior region (canine to canine) to simulate three levels of diastema (2.5 mm, 5 mm, 10 mm) and four levels of crowding (3 mm, 6 mm, 9 mm, 12 mm), along with an unmodified control. Eight digital models were fabricated using LCD 3D printing, with 15 prints per group. Printed models were scanned and superimposed onto their respective reference models using Geomagic Control X. Surface deviations were analyzed via minimum, maximum, root mean square (RMS), and average positive and negative values. One-way ANOVA and Tukey’s HSD post-hoc test were used for statistical evaluation. Results: Significant differences were observed among diastema groups (p < 0.05), with the 5 mm group showing the widest deviation range. RMS and average deviation values were highest in the 2.5 mm and 5 mm diastema conditions. In the crowding groups, significant deviations in minimum and maximum values occurred only in the 12 mm group (p < 0.001 and p < 0.008, respectively). Conclusion: Severe anterior crowding (12 mm) and mild to moderate diastemas (≤5 mm) significantly impair the precision of 3D-printed dental models. These results highlight the importance of assessing digital model fidelity in cases with anterior spacing or crowding, to ensure accurate diagnosis and appliance fabrication.