Conventional and Digital Oral Splint Precision: A Crossover Randomized Clinical Trial

To compare the precision (i.e., adaptation and adjustment time, contacts, comfort, satisfaction, and retention) of one conventional and two digital oral (Michigan type) splints. The null hypothesis is that there is no significant differences between conventional and digital oral splints precision.

This crossover randomized clinical trial (RCT) included 20 bruxers (41.8 ± 13.2 years old, 6 men and 14 women), who underwent three different types of oral splints. The sample was randomly allocated into three groups: a) Group 1: conventional oral splints fabricated in centric relation (CR) with a 3mm interincisal opening using a Lucia's Jig; b) Group 2: 3D printed digital oral splints designed in a virtual articulator using the same scanned 3mm CR bite registration (virtual Lucia's Jig); and c) Group 3: 3D printed digital oral splints designed in a virtual articulator using a 3mm interincisal opening, achieved by raising the virtual interincisal pin from the maximal intercuspal position (MIP). After the initial adaptation, the evaluation of the contacts was performed using the Occlusense® (Bausch). The satisfaction, comfort, and retention levels were measured by means of a questionnaire.

The results favored both digital splints (Groups 2 and 3) despite non-significant differences in adaptation and adjustment time. Levels of comfort and satisfaction were greater in both digital splint groups as compared to the conventional one (Group 1); however, no significant differences were found among the three groups regarding retention and contacts. Finally, no significant differences between CR versus MIP digital oral splints (Groups 2 and 3) were found in any outcome.

The results support the use of partial or 100% digital workflows in the fabrication of oral splints as an alternative to conventional workflow, depending on time and cost efficiency.