Table 2.
Surface roughness parameters for uncoated and coated brackets and nickel–titanium (NiTi) and stainless steel archwires
| Brackets and arch wires | Coating material | Measuring range (µm) |
Roughness parameters | ||
|---|---|---|---|---|---|
| Arithmetic average roughness (Ra) (nm) |
Root mean square roughness (Rq) (nm) |
Total height of profile (Rt) (µm) |
|||
| Bracket slot base | Uncoated | 250 × 250 | 459.17 | 564.85 | 3.82 |
| Al2O3 | 250 × 250 | 331.53 | 426.17 | 3.93 | |
| TiN | 250 × 250 | 354.12 | 458.74 | 4.22 | |
| CrN | 250 × 250 | 276.85 | 360.34 | 2.94 | |
| Heat-activated NiTi arch wire (0.016-inch round) |
Uncoated | 250 × 500 | 439.34 | 564.88 | 5.74 |
| Al2O3 | 250 × 500 | 361.64 | 466.01 | 3.78 | |
| TiN | 250 × 500 | 391.99 | 534.36 | 6.66 | |
| CrN | 250 × 500 | 354.35 | 454.66 | 6.21 | |
| Stainless steel arch wire (0.019 × 0.025-inch rectangular) |
Uncoated | 250 × 500 | 234.44 | 268.25 | 2.13 |
| Al2O3 | 250 × 500 | 95.86 | 128.01 | 1.74 | |
| TiN | 250 × 500 | 105.15 | 132.67 | 1.25 | |
| CrN | 250 × 500 | 190.28 | 229.26 | 1.51 | |
Al2O3, alumina; TiN, titanium nitride; CrN, chromium nitride.