“…The Cohen’s kappa values for inter-reviewer agreement for the first and second rounds of study selection were 0.94 and 0.98, respectively. The reasons of exclusion were: (1) inclusion of human subjects with no diagnosis of periodontitis [ 29 , 30 , 31 , 32 , 33 ], (2) periodontal diagnosis based on partial clinical examination [ 21 ], (3) study protocol [ 34 ], (4) use of herbal gels subgingivally as local-drug delivery [ 35 , 36 , 37 , 38 , 39 , 40 ], (5) non-English publication [ 41 ] and (6) no full text available [ 42 ]. Meta-analysis was not possible due to the increased heterogeneity in the disease/health definitions, periodontal evaluation, follow-up times, study protocols, and the variety of herbs.…”