In 2010 Berchier et al reviewed the efficacy of two different concentrations of chlorhexidine mouthrinse ( 0.2 & 0.12% ). A critical appraisal of this review is now available on the American Dental Associations Evidence-based Dentistry website.
The commentator notes that a comprehensive search strategy was used although restricted to the English language. Eight studies involving 803 patients were included and a meta-analysis undertaken. Plaque accumulation was the only outcome measure that could be compared and there was a small significant difference in favour of the 0.2% solution although the clinical relevance is probably minor.
Berchier CE, Slot DE, Van der Weijden GA. The efficacy of 0.12% chlorhexidine mouthrinse compared with 0.2% on plaque accumulation and periodontal parameters: a systematic review. J Clin Periodontol. 2010 Sep;37(9):829-39. Epub 2010 Jul 7. Review. PubMed PMID: 20618550