Table 2. The Exact Search Strategy for PubMed on October 10, 2020.

PubMed	Search Strategy
#1	or between all keywords for P in title/abstract
#2	or between all keywords for I in title/abstract + 3 keywords in MeSH term
#3	or between all keywords for O in title/abstract + 1 in MeSH term
#4	clinical trial[MeSH Terms]) OR "randomized clinical trial*"OR randomized OR randomized OR clinical trial OR cross_over OR split_mouth
#5	animal* OR mice OR rat OR rats OR mouse OR in vitro OR in_vitro
#6	AND #2 AND #3 AND #4
#7	NOT #7