Table 2.
Comparison of mean differences of surface roughness, nanohardness and elastic modulus of different group of archwires
| Properties | Archwires groups | Mean difference | P | 95% CI | ||
|---|---|---|---|---|---|---|
| Lower bound | Upper bound | |||||
| Surface roughness | Rhodium | Control | 0.004 | 0.998 | −0.069 | 0.078 |
| Epoxy | Control | 1.224 | 0.000* | 1.151 | 1.298 | |
| Teflon | Control | 0.564 | 0.000* | 0.490 | 0.637 | |
| Epoxy | Rhodium | 1.220 | 0.000* | 1.147 | 1.293 | |
| Epoxy | Teflon | 0.660 | 0.000* | 0.587 | 0.734 | |
| Teflon | Rhodium | 0.560 | 0.000* | 0.486 | 0.633 | |
| Nano-hardness | Control | Epoxy | 3.096 | 0.000* | 2.714 | 3.477 |
| Control | Rhodium | 3.053 | 0.000* | 2.671 | 3.434 | |
| Control | Teflon | 3.072 | 0.000* | 2.690 | 3.453 | |
| Rhodium | Epoxy | 0.043 | 0.986 | −0.318 | 0.403 | |
| Rhodium | Teflon | 0.019 | 0.999 | −0.341 | 0.379 | |
| Teflon | Epoxy | 0.024 | 0.997 | −0.336 | 0.384 | |
| Elastic modulus | Control | Epoxy | 52.004 | 0.000* | 47.051 | 56.957 |
| Control | Rhodium | 51.350 | 0.000* | 46.396 | 56.303 | |
| Control | Teflon | 51.067 | 0.000* | 46.114 | 56.021 | |
| Rhodium | Epoxy | 0.654 | 0.978 | −4.016 | 5.324 | |
| Teflon | Epoxy | 0.937 | 0.939 | −3.734 | 5.607 | |
| Teflon | Rhodium | 0.283 | 0.998 | −4.388 | 4.953 | |
*P<0.05. CI=Confidence interval, SE=Standard error