A Pilot study on professional cleansing protocols for PMMA resins produced by CAD/CAM and 3D printing technologies: effects on surface roughness and color stability.

OBJECTIVES This in vitro pilot study evaluated the effects of two professional cleansing protocols on surface roughness and color stability of various resins for complete dentures.

METHODS 50 resin specimens were prepared and divided into five groups (n=10): Probase Hot (PH, Ivoclar AG), IvoBase CAD (IBC, Ivoclar AG), Ivotion Dent (ID, Ivoclar AG), Dima Print Denture Base (DPDB, Kulzer), and Dima Print Denture Teeth (DPDT, Kulzer). After a 7-day immersion in coffee solution, two cleansing protocols were applied: a chemical one using an alkaline solution, and a combined mechanical+chemical one involving an acid-based cleaning agent with a rotating needle device followed by the same chemical protocol. Surface roughness was measured before and after cleaning using a structured light profilometer (Confovis) connected to a microscope (Eclipse LV150N, Nikon). Color stability was assessed with a colorimeter (Easy_Color, SmartVision). One specimen per group underwent SEM analysis at baseline and after both protocols. The data analysis was performed by using Kruskal-Wallis test and post-hoc Dunn test for comparison.

RESULTS Surface roughness was not significantly affected by either protocol (p>0.05). All ΔE values were below the perceptibility threshold (ΔE<1.2), except for ID after both the chemical (ΔE=2.28) and the mechanical+chemical protocol (ΔE=2.39) and DPDB after both the chemical (ΔE=2.06) and the mechanical+chemical protocol (ΔE=2.33).

CONCLUSIONS Surface roughness and color stability of PMMA resins were not affected by the tested cleansing protocols, so they could be used by clinician during the periodically control visit.

CLINICAL SIGNIFICANCE The proposed cleansing protocols help preserve the long-term aesthetic and functional integrity of dentures, enhancing patient satisfaction and oral health.