Anthony Jackson DDS
Evidence suggests that some specific mouthrinses (chlorhexidine gluconate (CHX), essential oils, and cetyl pyridinium chloride (CPC)) may be effective at controlling plaque and gingivitis.
Do adults who use antimicrobial mouthrinses have less plaque and gingivitis than those who do not?
The author searched two electronic databases for articles published between 1983 and September 2009. An unconventional, two-stage approach was used to accomplish the goal of the study. First, the author searched the literature for SRs evaluating the efficacy of anti-plaque, anti-gingivitis mouthrinses evaluated in long-term (six months) randomized placebo-controlled trials.A priori inclusion criteria were (1) SRs of randomized trials; (2) randomization of adult participants to either an active agent or a placebo control and (3) participant evaluations after six months of product use. Second, the author determined the clinical relevance of the reported results by comparing the percent reduction in plaque and gingivitis attributable to the anti-plaque, anti-gingivitis mouthrinses to equivalent determinations made for the placebo group (attributable to adult prophylaxis and oral hygiene instructions alone).
This review included three SRs, two of which evaluated the quality of the underlying clinical trials. One review concluded that there was strong evidence to support the efficacy of mouthrinses with CHX and essential oils as anti-plaque and anti-gingivitis agents. Evidence for CPC was inconsistent and dependent on the formulation of the rinse. The mean gingivitis reductions due to active agents were 28.7 percent (Standard deviation (SD) ±6.5) for CHX, 18.2 percent (SD ±9.0) for essential oils and 13.4 percent (SD ±8.7) for CPC. The mean plaque reductions were 40.4 percent (SD ±11.5) for CHX, 27 percent (SD ±11.0) for essential oils and 15.4 percent (SD ±7.6) for CPC. The author calculated the percentage reduction ratio as a means of evaluating efficacy for only one of the included SRs, since he had determined that there were insufficient data in the other two remaining SRs for the calculation. These two SRs reported consistent conclusions, however, and to varying degrees support the efficacy of the interventions as anti-plaque and anti-gingivitis agents.
This SR of three SRs confirms an additive antimicrobial effect from mouthrinses, along with regular home care, in controlling plaque and gingivitis. This additive effect exceeds the amount of improvement in oral hygiene due to oral hygiene instructions and adult prophylaxis alone.
Source of Funding:
Johnson & Johnson
Importance and Context:
Gingivitis is common, and the addition of a simple intervention to prevent or decrease the inflammatory disease process is invaluable. Any intervention that clinicians can introduce to their patients to lower the amount of plaque accumulation and, therefore, gingivitis is important in maintaining optimal oral health.
Strengths and Weaknesses of the Systematic Review:
This SR included a narrow search strategy, leading to limited data to analyze, and the clinical question was not consistent throughout the SR. The author did not perform any bias assessment or analysis of heterogeneity among studies, mainly because some baseline information was lacking in some studies. The author included quantitative results from only one meta-analysis (MA), for which he was author . The statistical analyses were basic and involved mean and standard deviation calculations for plaque and gingivitis reduction, although some studies did not record both of these indices. The author did not perform a MA of the three SRs due to a lack of data from some of the studies. Only one person conducted this review.
Strengths and Weaknesses of the Evidence:
The author reported the strength of the CHX used, but did not mention the type and strength of the essential oils studied. The number, gender and race of participants in each study were not reported; and the number of studies in each SR varied. No statistical significance is given for the studies. Most of the data came from one SR that included 24 studies. This was the most robust review out of those included, but was written by the author of the current SR. The values listed in the SR represent the effect of the agents alone, without any effect due to improved home care or the Hawthorne effect (the theory that the behavior of an individual will change to meet the expectations of the observer if they are aware that the behavior is being observed). The studies included in this SR used surrogate endpoints (gingival index and plaque index), which commonly allows researchers to reduce the duration of clinical trials and thereby use fewer participants in their study while still obtaining measurable outcomes. However, because surrogate endpoints differ from and may not correlate with clinical endpoints, they do not demonstrate efficacy in the same way that a clinical endpoint such as tooth loss would in a periodontal study. Lastly, this author was a paid consultant for the company who sponsored the research paper.
Implications for Dental Practice:
Some evidence in this review suggests that adding a mouthrinse containing an active agent to a brushing and flossing regimen provides limited additional plaque and gingivitis reduction. The review suggests no changes to current standard practice regarding mouthrinses, but it does confirm the usefulness of recommending mouthrinses as an adjunct to standard oral hygiene for patients in need of additional relief. CHX exhibited better results than essential oils and CPC, confirming current practice patterns where CHX is recommended as the first line of defense in the treatment of gingivitis. High quality clinical trials comparing these agents’ use in a standardized manner would be more useful to determine results more accurately. References:  Gunsolley JC. A meta-analysis of six-month studies of antiplaque and antigingivitis agents. JADA 2006 Dec;137(12):1649-57.