Implant-supported fixed complete denture frameworks in additively and subtractively manufactured high-performance...

To compare the fabrication and fit accuracy of additively (AM) and subtractively (SM) manufactured implant-supported fixed complete denture (ISFCD) frameworks in high-performance polymers with those in titanium.

An edentulous maxillary model with four implants (right first molar, right canine, left canine, and left right first molar) was digitized to design an ISFCD framework, which was used to fabricate a total of 50 frameworks in polyetheretherketone (AM-PEEK and SM-PEEK), polyetherketoneketone (AM-PEKK and SM-PEKK), and titanium (SM-Ti) (n = 10). A laboratory scanner was used to digitize each framework and when the frameworks were seated on the model at the left first molar site with the 1-screw test. The scan files of the frameworks were superimposed over the design file to evaluate the surface and interimplant deviations, while the fit at right first molar, right canine, and left canine sites was assessed with the average gap values. Data were statistically analyzed (α = 0.05).

SM-PEEK and SM-Ti frameworks mostly had higher and AM frameworks mostly had lower surface accuracy (P ≤ 0.036). SM-Ti and SM-PEEK frameworks had the lowest molar-to-molar interimplant distance deviations, and AM frameworks had the lowest precision of interimplant distances (P ≤ 0.014) AM-PEKK frameworks mostly had lower average gap accuracy regardless of the abutment site, followed by AM-PEEK (P < 0.001).

SM-PEEK and SM-Ti frameworks mostly had higher and AM frameworks mostly had lower accuracy. AM frameworks had larger marginal gaps. Tested frameworks tended to distort towards the midline.