Retention of 3-D-Printed, Milled, and Conventionally Fabricated Occlusal Splints

BACKGROUND Dental occlusal splints (OSs) are intraoral devices routinely used for management of temporomandibular dysfunctions (TMD), bruxism, and occlusal instability and to reduce dental attrition and wear. There are limited data on retention of OSs. This study aimed to evaluate the retention of the occlusal splint samples fabricated by conventional, 3D-printed, and milled methods. MATERIAL AND METHODS The study included total 120 samples divided into 3 groups: conventionally-fabricated (COSs), milled (MOSs), and 3D-printed OS (3DP OSs) (40 samples in each group). Retention was measured using an electronic vertical pull device. Splints were fabricated using standardized workflows, with a focus on uniform design and material and technique specifications. Statistical analysis was conducted using one-way ANOVA and Tukey's post hoc test for group comparisons. RESULTS Retention forces significantly varied across the 3 groups (p<0.001). The recorded mean retentive forces in conventional, milled, and 3DP OSs were 16.4±4.94; 6.42±2.13; 4.42±1.53, respectively. Furthermore, Tukey's post hoc test was used for pairwise comparison among the groups, showing statistically significant differences (p<0.001) between the retentive forces for conventional and digitally fabricated OS. CONCLUSIONS The retentive force for the conventionally produced splints was more than those produced digitally. The results showed significant variations in retention between conventionally made, milled, and 3D-printed splints, with digitally-made OSs achieving clinically adequate retention to maintain its position without causing trauma to the oral structures.