Surface geometry of various nanofiller composites using different polishing systems: A comparative study

Area of Science:

• Dental Materials Science
• Surface Engineering
• Nanotechnology in Dentistry

Background:

• Nanoparticle composites are widely used in restorative dentistry.
• Achieving optimal surface quality is crucial for the longevity and aesthetics of dental restorations.
• Various polishing systems exist, but their efficacy on different composite types varies.

Purpose of the Study:

• To evaluate the surface quality of three nanoparticle composites after polishing with four commercial systems.
• To compare the effectiveness of different polishing systems on surface roughness (Ra and Rz).
• To determine the influence of polishing steps on the surface characteristics of nanofilled and nanohybrid composites.

Main Methods:

• An in vitro study involving 180 specimens of three nanocomposites: Filtek Z-350 XT, Ceram-X Mono, and Tetric N-Ceram.
• Specimens were divided into five groups: one control (untreated) and four treated with polishing systems (SpinBrite, CompoMaster, AstroPol, SofLex).
• Surface roughness (Ra and Rz) was measured using Perthometer and analyzed with two-way ANOVA and Tukey's tests.

Main Results:

• Control specimens exhibited the roughest surfaces across all materials.
• For Filtek Z-350 XT, two-step polishing showed an insignificant decrease in surface roughness.
• Ceram-X and Tetric N-Ceram showed no significant roughness reduction with certain one-step or multi-step polishing protocols.

Conclusions:

• Surface roughness of nanofilled composites decreases with more polishing steps.
• One-step and multi-step polishing yield similar smoothness for nanohybrid composites.
• The type of finishing/polishing system is the primary determinant of surface roughness (Ra and Rz) for these composites.