Effects of polishing systems on surface properties and color stability of 3D-printed resin restoratives

To evaluate the effects of different polishing systems on surface roughness (Ra, Rz, Sa), water contact angle and color stability (ΔE₀₀) of a 3D printed permanent resin material.

50 specimens were fabricated using a Saremco Print Crowntec resin with 3D printer and divided into five equal groups: Control (No treatment); Sof-Lex XT; Diacomp Plus Twist; Optiglaze Color Clear; and Ultradent Diamond Polish. Surface roughness was evaluated using a 3D non-contact profilometer, and surface morphology was examined by scanning electron microscopy (SEM). Contact angle was measured using the sessile drop method and analyzed with software. Color change was measured by a spectrophotometer after 15 days of storage in coffee solution. Data were compared by one-way ANOVA and Tukey post hoc test (α= 0.05).

Optiglaze showed significantly higher Ra and Rz values than the other polishing systems (P< 0.05). The Ra value of the Diacomp Plus Twist group was lower than the Diamond Polish group; the Sa value was higher than the Sof-Lex XT and Diamond Polish groups (P< 0.05). The Diacomp Plus Twist group exhibited a higher water contact angle than the Optiglaze and Diamond Polish groups (P<0.05). Sof-Lex XT showed higher ΔE₀₀ compared to other polishing systems (P< 0.05). All polishing groups showed lower parameter values than the control group (P< 0.001).

These findings indicate that mechanical polishing might enhance the long-term esthetic results and color stability of 3D-printed permanent resin restorations. Clinical studies are required to validate intraoral efficacy.