Accuracy of CAD/CAM-based subtractive versus digital light processing fabricated mono-block splints for TMD management: An in vitro study.

OBJECTIVES

A newly designed Mono-Block (MB) splint has demonstrated promising clinical potential for treating temporomandibular disorders (TMD). The accuracy of MB splint fabrication is critical to the effectiveness of TMD treatment; however, it remains insufficiently defined. This study aimed to investigate the impact of subtractive manufacturing (SM) and additive manufacturing (AM) technologies on the trueness and precision of MB splints.

METHODS

Splint samples were fabricated using a representative AM technique (digital light processing, DLP) and an SM method (milling). Following fabrication, all samples were scanned and analyzed using 3D inspection software. Root mean square (RMS) values were measured to assess trueness and precision, and color maps were generated to detect deviations. Statistical analyses were conducted using Mann-Whitney U tests and unpaired t-tests.

RESULTS

SM splints exhibited significantly higher trueness than AM splints in the maxillary and mandibular marginal areas and the mandibular intaglio surface (p<0.0001). No significant difference was observed in the maxillary intaglio surface (p=0.143). Regarding precision, SM splints demonstrated greater precision in the mandibular marginal area (p<0.0001), while AM splints exhibited higher precision in the maxillary marginal area (p=0.004). No significant differences in precision were found for the maxillary (p=0.876) and mandibular (p=0.311) intaglio surfaces.

CONCLUSION

The manufacturing method significantly influenced MB splint accuracy. SM splints exhibited superior trueness, while both fabrication methods demonstrated comparable precision. Accuracy was greater in the mandibular section and the intaglio surface compared to other areas.

CLINICAL SIGNIFICANCE: All splints produced by SM or AM manufacturing methods meet the clinical requirements. However, regarding accuracy, SM splints appear to be the preferred choice.