An Adjunct to Mechanical Plaque Removal

In recent years,the over-the-counter therapeutic rinse market has grown dramatically. New formulas, agents, and flavors offer patients options to select a rinse that provides bacterial reduction, gingival health benefits, and a pleasant usage experience. The accessibility and affordability of therapeutic rinses makes them a viable tool to consider for the broader patient population. Oral rinses have a long history of use as adjuncts to mechanical plaque removal and have significantly provided benefits to many patients unable to use the necessary mechanical plaque control methods.

Given that meticulous mechanical plaque control may pose challenges for many patients, the use of an effective antimicrobial plaque control agent can prove advantageous when incorporated into an existing oral hygiene regimen. In fact, the need for additional assistance in controlling bacterial plaque justifies the use of mouthrinses with proven clinical effectiveness as adjuncts to a patient’s self-care regimen.

Using mouthrinse as a substitute for mechanical plaque control should be discouraged as mouthrinses are unable to significantly penetrate subgingivally.¹ Accordingly, no mouthrinses have received acceptance by the American Dental Association Council on Scientific Affairs for the treatment of periodontitis. However, when mouthrinses are used in conjunction with routine recommendations of twice daily brushing and daily interproximal cleaning, the action of rinsing with active antimicrobial agents proven therapeutic and safe provides adjunctive benefits in patients with gingival inflammation. Oral health professionals are always seeking additional plaque control measures in order to successfully achieve treatment outcomes and/or maintain optimal gingival health for their patients. Identifying and recommending the appropriate antimicrobial plaque control agents to meet specific patient needs are important to overall oral health. Understanding the clinical data that support the antiplaque and antigingivitis benefits of these new oral rinse products prior to making recommendations is essential for evidence-based decision making.

COMMON RINSE AGENTS

Various ingredients are used in oral rinses for therapeutic and cosmetic purposes. Three common therapeutic agents are chlorhexidine bioavailability, high cetylpyridinium chloride (CPC), and essential oils. All three agents have been clinically shown to produce significant gingival and plaque control benefits when formulated at therapeutic concentrations.^2-13 Chlorhexidine is the most effective therapeutic prescription rinse approved for clinical use as an antiplaque and antigingivitis agent. High bioavailable CPC and essential oils are the only two antimicrobial systems for over-the-counter rinses that are classified by the Food and Drug Administration (FDA) Dental Plaque Subcommittee as safe and effective for the treatment of plaque-induced gingivitis.¹³

PRESCRIPTION RINSE AGENTS

Chlorhexidine gluconate is the gold standard for chemotherapeutic oral rinses. It is a cationic compound, which favors attraction to tooth surfaces and has activity against a broad range of bacteria.¹⁴ In the United States, the most commonly prescribed chlorhexidine rinse contains 0.12% chlorhexidine with 11.6% alcohol. Recently, an alcohol-free formulation was introduced in the United States.

Numerous clinical studies have evaluated chlorhexidine rinses at concentrations ranging from 0.12% to 0.2%2,5-8 and report excellent efficacy for gingivitis, gingival bleeding, and plaque. Recent 6-month studies of 0.12% formulations show 18% to 33% reductions in gingivitis and 22% to 31% reductions in plaque.^2,6 Trials of 0.2% chlorhexidine formulations tended to show slightly higher benefits.^5,7,8

An extensive body of published data supports the safety of chlorhexidine.^2,5-8 Long-term use is generally avoided because of the potential for extrinsic stain development, increased calculus formation, and taste alteration.¹⁵

OVER-THE-COUNTER RINSE AGENTS

CPC is a broad-spectrum antimicrobial agent with a long history of use to promote gingival health. It penetrates the cell membrane, causing leakage of cell components, disruption of bacterial metabolism, inhibition of cell growth, and ultimately cell death.¹⁶ The FDA Plaque Committee concluded that CPC rinses must be formulated at concentrations of 0.045% to 0.1% CPC with at least 72% to 77% chemically available cetylpyridinium chloride to be considered safe and effective in an antigingivitis/antiplaque rinse.¹³ Therapeutic CPC rinses can be marketed in alcohol-containing formulations or in alcohol-free combinations. Rinses with lower CPC concentrations or with less chemically available CPC are marketed as cosmetic products for the temporary control of halitosis.

The specific criteria for the concentration and bioavailability of CPC were established because CPC’s efficacy can be affected by other ingredients in the product formulation.¹⁷ Certain excipients (various inert ingredients added to give the mixture the desired consistency or form), eg, surfactants, can bind CPC, diminishing its ability to provide antiplaque and antigingivitis benefits.¹⁷ Formulations with high bioavailable CPC are associated with greater biological activity, therefore, suggesting an increased probability for clinical efficiency.¹⁸

Three 6-month clinical studies measuring plaque and gingivitis benefits from four different therapeutic CPC formulations have been published since 1998.^2-4 All CPC rinses produced statistically significant benefits versus placebo for plaque and gingivitis. Reductions ranged from 15% to 24% for gingivitis, 27% to 67% for bleeding, and 16% to 28% for plaque.

The safety of CPC is well-documented.^2-4,13 As with any antimicrobial rinse, a small percentage of patients may experience temporary taste alteration and/or transient extrinsic staining.¹⁹ These side effects generally occur less often in over-the-counter rinses when compared to prescription rinses.

The FDA Dental Plaque Subcommittee recommended essential oils as a safe and effective active system for over-the-counter antiplaque/antigingivitis rinses when formulated as a combination of 0.092% eucalyptol, 0.042% menthol, 0.06% methyl salicylate, and 0.064% thymol in a hydroalcoholic vehicle containing 21.6% to 26.9% alcohol.¹³ Essential oils rinses work by disrupting the bacterial cell wall and inhibiting its enzyme activity.¹⁹

The antiplaque and antigingivitis efficacy of essential oils has been well documented in the literature. Long-term trials, including those involving flossing and rinsing, showed reductions in gingivitis from 12% to 30% and plaque reductions from 21% to 56% when compared to a placebo.^6,9-12 The safety of essential oils is also well-established.^6,9-12,13 Some patients may have difficulty tolerating the burning associated with the alcohol in the formula²⁰ and as typical with antimicrobial rinses, light extrinsic staining may occur.⁶

Any patient taking medications where adverse reactions with alcohol may occur should select alcohol-free mouthrinses, as well as those patients who are undergoing chemotherapy or recovering alcoholics and/or substance abusers. Patients who exhibit and/or suffer from xerostomia should also be advised to select an alcohol-free mouthrinse.^21,22

CONCLUSION

Therapeutic rinses are not intended to replace proper mechanical hygiene methods, but rather provide an additional means for improved plaque and gingivitis control. Benefits from therapeutic rinses can only be achieved when patients adhere to recommended regimens designed for improved gingival health. As professionals, we must consider selecting the appropriate rinse based on patient need and recognize new formulations that may increase compliance, thereby making mouthrinsing a desirable adjunctive therapeutic approach in controlling plaque and gingivitis between regular dental visits.

REFERENCES

1. Ciancio SG. Nonsurgical periodontal treatment. Presented at: World Workshop in Clinical Periodontics; 1989; Chicago.
2. Stookey GK, Beiswanger B, Mau M, Isaacs RL, Witt JJ, Gibb R. A 6-month clinical study assessing the safety and efficacy of two cetylpyridinium chloride mouthrinses. Am J Dent. 2005;18:24A-28A.
3. Mankodi S, Bauroth K, Witt JJ, et al. A 6-month clinical trial to study the effects of a cetylpyridinium chloride mouthrinse on gingivitis and plaque. Am J Dent. 2005;18:9A-14A.
4. Allen DR, Davies R, Bradshaw B, et al. Efficacy of a mouthrinse containing 0.05% cetylpyridinium chloride for the control of plaque and gingivitis: a 6-month clinical study in adults. Compend Contin Educ Dent. 1998;19:20-26.
5. Quirynen M, Soers C, Desnyder M, Dekeyser C, Pauwels M, van Steenberghe D. A 0.05% cetyl pyridinium chloride/0.05% chlorhexidine mouth rinse during maintenance phase after initial periodontal therapy. J Clin Periodontol. 2005;32:390-400.
6. Charles CH, Mostler KM, Bartels LL, Mankodi SM. Comparative antiplaque and antigingivitis effectiveness of a chlorhexidine and an essential oil mouthrinse: 6-month clinical trial. J Clin Periodontol. 2004;31:878-884.
7. Hase JC, Attstrom R, Edwardsson S, Kelty E, Kisch J. 6-month use of 0.2% delmopinol hydrochloride in comparison with 0.2% chlorhexidine digluconate and placebo. (I). Effect on plaque formation and gingivitis. J Clin Periodontol. 1998;25:746-753.
8. Lang NP, Hase JC, Grassi M, et al. Plaque formation and gingivitis after supervised mouthrinsing with 0.2% delmopinol hydrochloride, 0.2% chlorhexidine digluconate and placebo for 6 months. Oral Dis. 1998;4:105-113.
9. Sharma N, Charles CH, Lynch MC, et al. Adjunctive benefit of an essential oil-containing mouthrinse in reducing plaque and gingivitis in patients who brush and floss regularly: a six-month study. J Am Dent Assoc. 2004;135:496-504.
10. Bauroth K, Charles CH, Mankodi SM, Simmons K, Zhao Q, Kumar LD. The efficacy of an essential oil antiseptic mouthrinse vs. dental floss in controlling interproximal gingivitis: a comparative study. J Am Dent Assoc. 2003;134:359-365.
11. Sharma NC, Charles CH, Qaqish JG, Galustians HJ, Zhao Q, Kumar LD. Comparative effectiveness of an essential oil mouthrinse and dental floss in controlling interproximal gingivitis and plaque. Am J Dent. 2002;15:351-355.
12. Charles CH, Sharma NC, Galustians HJ, Qaqish J, McGuire JA, Vincent JW. Comparative efficacy of an antiseptic mouthrinse and an antiplaque/antigingivitis dentifrice. A six-month clinical trial. J Am Dent Assoc. 2001;132:670-675.
13. Food and Drug Administration, Department of Health and Human Services. Oral health care drug products for over-the-counter human use; antigingivitis/antiplaque drug products; establishment of a monograph; proposed rules. Federal Register. 2003; May, 29.
14. Paraskevas S. Randomized controlled clinical trials on agents used for chemical plaque control. Int J Dent Hygiene. 2005;3:162-178.
15. Ciancio SG. Antiseptics and antibiotics as chemotherapeutic agents for periodontitis management. Compend Contin Educ Dent. 2000;21:59-62, 64, 66 passim; quiz 78.
16. Scheie AA. Models of action of currently known chemical antiplaque agents other than chlorhexidine. J Dent Res. 1989;68:1609-1616.
17. Jenkins S, Addy M, Wade W, Newcombe RG. The magnitude and duration of the effects of some mouthrinse products on salivary bacteria counts. J Clin Periodontol. 1994;21:397-401.
18. Hunter-Rinderle SJ, Bacca LA, McCaughlin KT, et al. Evaluation of cetylpyridinium chloride-containing mouthwashes using in vitro disk retention and ex vivo plaque glycolysis methods. J Clin Dent. 1997;8:107-113.
19. Fine DH. Mouthrinses as adjuncts for plaque and gingivitis management. A status report for the American Journal of Dentistry. Am J Dent. 1988;1:259-263.
20. Bolanowski SJ, Gescheider GA, Sutton SVW. Relationship between oral pain and ethanol concentration in mouthrinses. J Periodont Res. 1995;30:192-197.
21. Daniel SJ, Harst SA. Dental Hygiene Concepts, Cases, and Competencies. St Louis: Mosby; 2004: 418.
22. ADA Division of Communications. Do you have dry mouth? J Amer Dent Assoc. 2002;133:1455.

From Dimensions of Dental Hygiene. April 2006;4(4): 32, 34.