Research Article
A Clinical Comparison of Failure Rates of Metallic and Ceramic Brackets: A Twelve-Month Study
Table 4
The Cox proportional hazards model for 6- and 12-month observation periods.
| | | Coefficient β | Hazard ratio | 95% CL | |
| | Ceramic brackets (6 months) | | 1.00 | 1.00 | | | Metal brackets (6 months) | −1.752 | 0.173 | 0.039–0.775 | 0.022 | | Ceramic brackets (12 months) | | 1.00 | 1.00 | | | Metal brackets (12 months) | −1.913 | 0.148 | 0.034–0.650 | 0.011 |
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