Polishing Procedure and Toothbrush Abrasion Effect on Composite Surface Quality Objective: The study examined the effect of polishing procedure and toothbrush abrasion on gloss and surface roughness of 4 different composite materials. Methods: The studied composite materials were two micro-hybrid-composites Venus (VE, Heraeus Kulzer) and Tetric Evo Ceram (TEC, Ivoclar Vivadent) and two nano-composites Grandio (GR, Voco) and an experimental composite (EC, Heraeus Kulzer). 16 flat specimen of each composite were made. Half of the specimen (n= 8) were mechanically polished (pol), the other half were ground with 320-grit SiC paper (unpol). Toothbrush abrasion (TA) with 100,000 brushing cycles was done for both groups. Gloss was defined as percentage of the totally reflected light from a perfect mirror (=100 %). Reflection (%) and average surface roughness R
a (µm) were measured with a surface laser scanner (UBM) before and after TA. Statistical analysis by ANOVA. Results: A significant difference in gloss and roughness between the two groups was found (p
£0,05 ). After TA the difference between the two groups regarding the gloss was still significant. The best gloss results after TA were achieved with EC (pol:6,5%/unpol:5,8%) and with TEC (pol:5,8%/unpol:5,9%). Roughness got significantly reduced after TA in group unpol. In group pol TA led to higher roughness for the microhybrid-composites compared to the nano-composites.
| Reflection(%)/ | Roughness(µm) | |
| | VE | TEC | GR | EC | |
| TA | pol | unpol | pol | unpol | pol | unpol | pol | unpol | |
| before | 7,4/0,10 | 3,0/0,61 | 7,9/0,05 | 2,9/0,56 | 7,0/0,15 | 2,6/0,56 | 7,7/0,05 | 3,4/0,43 | |
| after | 5,5/0,57 | 4,7/0,29 | 5,8/0,42 | 5,9/0,29 | 5,7/0,17 | 3,8/0,20 | 6,5/0,13 | 5,8/0,27 | |
Conclusions: The gloss of polished composites was clearly reduced after the simulated toothbrush abrasion, however it was still higher than in the unpolished group. The different performance regarding roughness of the polished composites is due to the particle size of the composite material.