Of 394 subjects screened, 136 were enrolled and randomized in Phase I, 67 to PZW and 69 to UOB (mean age, 50 years). Of these, 134 were randomized in Phase II, 67 to SDC and 67 to MTB. One hundred thirty-three subjects completed the study.
Phase I efficacy
For the primary endpoint, DE at Day 7, a significantly larger reduction was observed for PZW than UOB, with Kruskal-Wallis median DE values of 6.34 and 4.08, respectively, p-value = 0.0059.
Significant differences in tooth shade were also observed at Day 7 per VCS, with LS Mean (SE) reductions of 4.92 (0.20) for PZW, and 4.19 (0.20) for UOB, p-value = 0.0106.
Significant differences in tooth shade at Day 7 were also observed per VBG, with LS Mean (SE) reductions of 2.41 (0.13) for PZW, and 2.06 (0.12) for UOB, p-value = 0.0489.
Phase II efficacy
On Day 90, the SDC was statistically superior to MTB in maintaining shade per VCS, with LS Mean (SE) reduction of 0.77 (0.22) for SDC and 0.47 (0.22) for MTB, p-value = 0.0001.
For VBG at Day 90, the LS Mean (SE) reduction was 0.29 (0.12) for SDC and 0.15 (0.12) for MTB, p-value = 0.0108.
No tooth color differences were observed per DE.
The percentage of subjects who reported “no sensitivity” immediately post-bleaching was 98.5% for PZW, and 98.6% for UOB. At Day 7, these values were 82.1% for PZW, and 79.4% for UOB. Of those who did experience sensitivity, one subject rated sensitivity as “moderate.” All other reports were characterized as “mild.”
There was a total of 41 adverse events reported among 34 subjects. In general, these events were associated with sensitivity. Subject use of post-bleaching sensitivity gel (Relief ACP and UltraEZ) was low. Four subjects (two per treatment group) used the products at Day 1 post-bleaching, and one subject used the product on Day 2. There are no other reports of use thereafter.