Some of the conditions mouthrinses are designed to address are discussed in the following sections.
Alveolar Osteitis (Dry Socket)
Alveolar osteitis (AO), also known as dry socket, is a common postoperative condition following dental extraction procedures, particularly those of the third molar.7AO occurs when the fibrin clot that forms following extraction is dislodged. AO usually results in intense pain in and around the extraction site 2 to 3 days after the procedure. A recent systematic review and meta-analysis of 18 trials7 has shown chlorhexidine, without the use of antibiotics, to be effective for lowering the risk of AO following third molar extractions. A moderate, but statistically not significant, increase in efficacy was seen in the gel formulation compared with the rinse formulation; however, the review could not recommend a specific dosing regimen. Studies included in the review reported minor, nonclinical reactions to chlorhexidine, including staining of teeth, dentures, and tongue, and altered taste.
Oral Malodor (Bad Breath)
Volatile sulfur compounds (VSCs) are the major contributing factor to oral malodor or bad breath. They arise from a variety of sources (e.g., breakdown of food, dental plaque and bacteria associated with oral disease).3 Cosmetic mouthrinses can temporarily mask bad breath and provide a pleasing flavor, but do not have an effect on bacteria or VSCs. Mouthrinses with therapeutic agents like antimicrobials, however, may be effective for more long-term control of bad breath. Antimicrobials in mouthrinse formulations include chlorhexidine, chlorine dioxide, cetylpyridinium chloride, and essential oils (e.g., eucalyptol, menthol, thymol, and methyl salicylate). Other agents used in mouthrinses to inhibit odor-causing compounds include zinc salts, ketone, terpene, and ionone.1 Although the combination of chlorhexidine and cetylpyridinium chloride plus zinc lactate has been shown to significantly reduce bad breath, it also may significantly contribute to tooth staining.3, 8
Plaque and Gingivitis
When used in mouthrinses, antimicrobial ingredients like cetylpyridinium chloride, chlorhexidine, and essential oils have been shown to help reduce plaque and gingivitis when combined with daily brushing and flossing.5, 9While some studies have found that chlorhexidine achieved better plaque control than essential oils, no difference was observed with respect to gingivitis control. Cetylpyridinium chloride and chlorhexidine may cause brown staining of teeth, tongue, and/or restorations.4
Preprocedural Mouthrinse
Some dental equipment and procedures, including ultrasonic scalers, air polishing, air-water syringe and tooth polishing with air turbine handpieces or air abrasion, generate aerosols, a mix of liquid and solid particles.10, 11Aerosols can remain airborne for up to four hours before settling on surrounding surfaces.12 In addition to settling on environmental surfaces, aerosols containing microorganisms can be inhaled by dental care providers, posing a risk for disease transmission.11Respiratory diseases associated with aerosols include influenza, and tuberculosis, as well as COVID-19 SARS-CoV-2.110, 11
Research suggests that having a patient use a mouthrinse prior to treatment may reduce the amount of aerosolized microorganisms. However, there is no evidence that preprocedural mouthrinse protects against clinical disease among dental staff.11
Bacteriocidal effect of preprocedural mouthrinses. The evidence suggests that preprocedural mouthrinse is effective at reducing bacterial contamination in dental aerosols.12Certain antimicrobial rinse solutions used from 30 seconds to 2 minutes versus water or no rinse effectively reduced aerosol contamination produced during periodontal prophylaxis.12For example. chlorhexidine (either 0.12 or 0.2%) is an effective antimicrobial solution for this purpose.12One drawback, however, is that chlorhexidine can cause tooth staining, supragingival calculus formation, and a change in taste sensation.13Researchers also, though, have found comparable performance between chlorhexidine and cetylpyridinium chloride as a preprocedural rinse in reducing bacterial load in aerosols. 11
Virucidal effect of preprocedural mouthrinses. Although little clinical data have been collected ,12one small study found that preprocedural rinses, including normal saline, reduced SARS-CoV-2 viral load in saliva. 14
One review of four in vitro studies, however, found that a preprocedural rinse with chlorhexidine was effective at reducing viral load. 13Essential oils also were shown to have antiviral properties against enveloped viruses.13
Overall, there is a need for additional research concerning the role of preprocedural mouthrinses in preventing viral infections.12
Tooth Decay
Fluoride ions, which promote remineralization, may be provided by certain mouthrinses. A Cochrane systematic review found that regular use of fluoride mouthrinse reduced tooth decay in children, regardless of exposure to other sources of fluoride (i.e., fluoridated water or toothpaste containing fluoride).15
Topical Pain Relief
Mouthrinses that offer pain relief most commonly contain topical local anesthetics such as lidocaine, benzocaine/butamin/tetracaine hydrochloride, dyclonine hydrochloride, or phenol.1 In addition, sodium hyaluronate, polyvinylpyrrolidine and glycyrrhetinic acid may act as a barrier to relieve pain secondary to oral lesions, like aphthous ulcers.1
Whitening
Mouthrinse may contribute to extrinsic stain reduction when either carbamide peroxide or hydrogen peroxide are among the active ingredients. Products that rely on carbamide peroxide typically contain 10 percent carbamide peroxide and may be dispensed by dentists to their patients for use at home.16 Mouthrinses that claim to whiten teeth also may contain 1.5 to 2 percent hydrogen peroxide.1One study found that 12 weeks' use of mouthrinse containing hydrogen peroxide in this concentration range achieved similar color alteration as that achieved by 2 weeks' use of 10 percent carbamide peroxide whitening gel.17
Xerostomia
Xerostomiais a reduction in the amount of saliva bathing the oral mucous membranes. Since the lack of saliva increases the risk of caries, a fluoride-containing mouthrinse may be helpful to those managing this problem. However, since alcohol can be drying, it may be prudent to recommend an alcohol-free mouthrinse.18Mouthrinses containing enzymes, cellulose derivatives and/or animal mucins can mimic the composition and feel of saliva and may provide additional relief from symptoms associated with xerostomia.1
Oral Cancer Concern
Alcohol consumption as well as alcohol and tobacco use are known risk factors for head and neck cancers.19Resulting from this has been the question of whether use of alcohol-containing mouthrinse increases risk of these cancers.20A recent systematic review and meta-analysis failed to find an association between mouthrinse use and oral cancer, use of alcohol-containing mouthrinse and oral cancer, or mouthrinse dose response and oral cancer.21
