Table 4: Two by two comparison of OHRQoL scores.

Grade 3
 Experimental
Grades 4
 Experimental
Grade 3 Control Grades 4
control
a & b a & c c & d b & d
1.12 ± 1.69a 3.88 ± 3.22b 8.25 ± 3.88c 20.76 ± 6.64d 0.001 0.001 0.001 0.001