Short-Term Clinical Outcomes of Ready-Made Soft Splints Versus Digitally Fabricated, Customized Hard Stabilization Splints in Temporomandibular Disorders: An Exploratory Randomized Study

Background/Objectives: Occlusal splints are widely used for temporomandibular disorders (TMDs), but direct evidence comparing ready-made soft splints with customized hard stabilization splints remains limited. This exploratory randomized study compared the short-term clinical outcomes of a ready-made soft splint and a digitally fabricated, customized 3D-printed hard stabilization splint, representing two distinct fabrication and delivery workflows. Methods: Seventy adults with TMDs were randomized 1:1 to a customized hard splint fabricated using intraoral scanning and digital light processing 3D printing or to a ready-made soft splint (n = 35 per group); 68 completed follow-up. Modified Helkimo index scores were assessed at baseline (T0), 4 weeks (T1), and 12 weeks (T2). Results: Scores decreased significantly from baseline in both groups at T1 and T2 (all p < 0.001). No statistically significant between-group difference was detected in change from baseline to T1 (Hodges–Lehmann median difference, hard minus soft = 0.00; 95% CI, −1.00 to 1.00; p = 0.573) or T2 (−1.00; 95% CI, −2.00 to 0.00; p = 0.209). Conclusions: No statistically significant difference in short-term clinical improvement was detected between the two splint groups. This finding should not be interpreted as evidence of equivalence or non-inferiority. Ready-made soft splints may have a limited, hypothesis-generating role as a short-term conservative or bridging option for selected patients, but adequately powered, prospectively registered non-inferiority trials are needed to define their clinical role. Trial Registration: CRIS KCT0012318 (retrospectively registered).