The Effect of Different Scaling Methods on the Surface Roughness of 3D-Printed Crowns: An In Vitro Study

Despite the growing adoption of 3D-printed resin materials, limited evidence exists on how clinical procedures such as scaling impact their surface integrity. This in vitro study evaluated the effect of different scaling methods on the roughness of five 3D-printed resin materials. Disc-shaped specimens from five commercially available 3D-printed crown materials (Crowntec, Varseosmile, Freeprint, Ezprint, and C&B Nextdent) were fabricated. Each material group (N = 30) was subjected to three scaling techniques: stainless-steel manual, plastic, and piezoelectric ultra-sonic scalers. Surface roughness (Ra) was quantified using a non-contact profilometer before and after scaling. One-way ANOVA was used to analyze the data. All the crowns exhibited increased roughness when treated with ultra-sonic scalers compared to the other scalers, and this was significant (<i>p</i> < 0.05) for all except VarseoSmile. Compared to the other crowns, Freeprint crowns (0.07 ± 0.04 µm) showed the greatest roughness change with plastic scalers, which was significant (<i>p</i> < 0.05) compared to C&B Nextdent crowns (0.001 ± 0.03 µm). For hand and ultra-sonic scalers, no significant differences were found among the crown types (<i>p</i> > 0.05). In conclusion, ultra-sonic scalers, while efficient, may increase surface roughness, potentially enhance plaque retention, and compromise prosthesis longevity.