Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Results of the clinical evaluation of marginal discoloration criterion
| 6 m | 12m | 18 m | 24 m | |||
|---|---|---|---|---|---|---|
| The control group | a | 53(96%) | 52(96%) | 52(96%) | 52(96%) | |
| b | 2（4%） | 2（4%） | 2（4%） | 2（4%） | ||
| The experimental group | a | 56(92%) | 51(93%） | 48(86%) | 48(86%) | |
| b | 5(8%) | 5(7%） | 8(14%) | 8(14%) | ||
| Fisher’s exact P-value | 0.719 | 0.438 | 0.094 | 0.094 | ||
