2399
PRO treatment suppressed the amount of tooth movement by 12 . 9 % in 3 - day ETM and by 32 . 2 % in 5 - day ETM compared with vehicle treatment .
 PRO
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 PRO