Table 4. Means (SD) values for weekly tooth sensitivity and degrees of tooth sensitivity reported by volunteers in different treatment groups.

Treatment	First day	1 week	2 weeks	1 week post-bleaching	2 weeks post-bleaching
In-office	1.57 (0.84)Aa	1.24 (0.36)Aa	1.31 (0.43)Aa	1.07 (0.27)Ab	1.00 (0.00)Ab
At-home	1.20 (0.51)Ba	1.37 (0.53)Ab	1.31 (0.54)Aab	1.02 (0.13)Aac	1.02 (0.13)Aac

* Different uppercase letters indicate differences between groups in each time of evaluation. **Different lowercase letters indicate differences between different periods of evaluation within each treatment group.