1. “I’m concerned with low pH and enamel erosion”
LISTERINE® has been safely used worldwide by more than one billion consumers for over 100 years. In more than 30 clinical studies, including long term (6 month) clinical trials, there has been no observation or report of erosion of tooth enamel. Additionally, in none of the studies did any subject report the onset of tooth hypersensitivity, a symptom often associated with erosion of root surfaces.
A clinical study evaluated the effect of rinsing with LISTERINE® on salivary pH and plaque pH. Following pretreatment pH determinations, subjects rinsed with tap water for 30 seconds and pH was monitored periodically over 30 minutes; after a 10 minute rest period, the procedure was repeated with LISTERINE® substituted for tap water. Both the plaque pH and the salivary pH remained well above the critical pH of 5.7 (where demineralization occurs) during the entire 30 minute period of the study).
In addition, it is important to note that LISTERINE® (pH 4.2) is rapidly neutralized by the buffers in saliva during and after rinsing and any drop in pH will be of extremely short duration, especially when compared to that of carbonated drinks and citrus drinks and fluids which are far more difficult to neutralize. Furthermore, LISTERINE® is an expectorated product; therefore the contact time of the mouthrinse with the tooth surface is short.
The evidence to date indicates that rinsing with LISTERINE according to label directions does not adversely affect enamel and confirms its safety for oral use.
2. “If patients rinse they might not floss.”
We believe that a healthy daily oral care regimen consists of brushing, flossing and rinsing. We have promoted this in our communications, emphasizing the benefit of each aspect of the regimen. In consumer research on a complete oral hygiene routine, using brush, floss and rinse, it has been found that consumers understand and appreciate the benefit of each of these steps in their oral care regimens. Similar concerns were raised by dental professionals when fluoride was first added to toothpaste. It was thought that patients might not brush as well as before if they believed simply exposing their teeth to fluoride would protect them against cavities. These concerns proved to be unfounded. Likewise, we believe that patients who already floss will not drop their existing good oral hygiene habits once they add twice daily rinsing with LISTERINE® to their regimen.
3. “I’m concerned that LISTERINE® will kill the good bacteria”
LISTERINE® is an effective antiseptic which kills the bacteria that cause plaque and gingivitis. In vitro studies have shown that LISTERINE® also kills 99.9 % of the bacteria that cause bad breath. Clinical studies have shown that LISTERINE® reduces the total bacterial load in the mouth to levels consistent with good oral health and does not alter the balance of the oral microbial flora.
1. Minah et al., J Clin Periodontol, 16:347 – 352, 1989
2. Walker, C. et al., J Dent Res., 68:412.Abstr 1845, 1989
4. “I don’t recommend rinsing after brushing as it may wash away the fluoride”
While studies have shown that rinsing even with water after brushing can lower the salivary fluoride content from immediately post-brushing, it does not appear that this is clinically significant with regards to the caries-reducing effect.1 Likewise, rinsing with LISTERINE®, which is 70% water, should not interfere with the caries-reducing effect of fluoride. The essential oils in LISTERINE® do not react with fluoride and both ingredients are found in LISTERINE® Essential Care toothpaste, which has demonstrated effective fluoride uptake in vitro and is an effective anti plaque/anti gingivitis dentifrice. LISTERINE® Teeth and Gum Defense and LISTERINE® Total Care rinses in ex-US markets also contain both essential oils and fluoride. In a clinical study, LISTERINE® Teeth and Gum Defense was shown to effectively promote enamel remineralization and fluoride uptake at least as well as a fluoride rinse without essential oils2. Finally, another study reported that salivary retention of fluoride after rinsing with a fluoride rinse was significantly greater than after brushing with a fluoride dentifrice alone, suggesting that a regimen combining brushing with a fluoride dentifrice followed by using a fluoride mouth rinse may be beneficial.3
1. Machiulskiene V et al. Caries Res. 36(5):301-7, 2002
2. Zero, DT et al., JADA, 135;231-237, 2004.
3. Zero, DT et al, J Dent Res, 71;1768-1775, 1992.
5. “I’m concerned that LISTERINE® may weaken dental restorations”
Published studies have shown that LISTERINE® does not weaken dental restorations.
In a study by Norman, R.D.1 the surface hardness effects on composite resins of various mouthrinses was determined. The author concluded that this study demonstrated that use of alcohol-containing mouthrinses (7.0%-26.9% alcohol) poses no increased risk for patients with composite resins. In another study2, in situ models were used to evaluate the effect of LISTERINE® on three common restorative materials - glass ionomer, composite resin, and amalgam. Samples of material were placed into intra oral devices which were worn by subjects for 12 hours each day for 10 days. During this time, subjects rinsed with LISTERINE® or a control rinse 2 times each day for 30seconds. After 10 days, the specimens were salvaged from the devices and inspected by visible and SEM examination. This study found that routine use of mouthrinses containing essential oils did not adversely affect restorative materials.
An additional study evaluated the effect of LISTERINE® in a dental unit self-contained water system on resin bond strengths3. Such systems consist of a reservoir of water isolated from the municipal water supply that is attached to dental unit water lines. The authors reported that exposing an etched dentin surface to a dilute mixture of LISTERINE® mouthrinse has no adverse effects on subsequent bonding procedures.
1. Norman, R.D. JDR, 76 (Special Issue):325 (Abstract #2490), 1997.
2. von Fraunhofer JA, et al. Gen Dent., 54(6):403-7, Nov–Dec 2006.
3. von Fraunhofer JA, et al, Gen Dent, 502-504, Nov-Dec 2004
6. “I’m concerned that LISTERINE® causes mucosal sloughing”
LISTERINE® has been safely used worldwide by more than one billion consumers for over 100 years. Its safety and effectiveness have been established in more than 30 published clinical studies. These studies have not shown evidence of mucosal sloughing associated with LISTERINE® when used as directed (20 mL for 30s, twice daily). Data from post market research show that these events are rare and usually associated with additional factors other than LISTERINE®. Several studies have also been conducted under exaggerated use conditions*. In one study, subjects used the rinse every 5 hours for 5 days. No subjects developed any mucosal lesions attributable to LISTERINE®. In a second similar study, one subject out of 45 experienced some mucosal sloughing on day 5 after 4 days of exaggerated use. Finally, in an exaggerated use study in a xerostomic population, 2 subjects out of 18 experienced some transient mucosal sloughing but continued the regimen. The FDA reviewed the potential for mucosal irritation in its “Oral Health Care Drug Products for Over-the-counter Human Use; Antigingivitis/Antiplaque Drug Products; Establishment of a Monograph; Proposed Rules” released in May 2003. The FDA concluded that the potential for mucosal irritation is minimal when LISTERINE® is used as directed.
*Studies cited in FDA’s ANPR on OTC Antigingivitis/Antiplaque Drug Products (unpublished) – Fishman, S.L. et al. Am. J. Dent., 17(1):23-6, 2004.
7. ‘Why do we need LISTERINE® when we can rinse with salt water?”
LISTERINE is an antiseptic mouthrinse which contains a combination of essential oils consisting of eucalyptol, menthol, methyl salicylate and thymol. Its effectiveness has been established in more than 30 published clinical studies. Salt water/saline does not contain any antimicrobials. In fact, saline is used as a negative control in some of our mouthrinse studies. A study* was conducted to determine the bactericidal effect of LISTERINE® when compared to a saline control on dental plaque bacteria in situ. Analysis of vital stained plaque specimens indicated that following rinsing with the LISTERINE® mouthrinse, 78.7% of bacteria were dead compared to 27.9% following rinsing with the saline.
*Pan, P et al. J Clin Periodontol., 27(4):256-61, 2000
8. “I’m concerned that LISTERINE® may not be safe for diabetics.”
Studies have shown that periodontal disease tends to be more severe in diabetic patients, especially poorly controlled diabetics. Strict plaque control should be an important part of a diabetic patient’s daily oral care regimen. LISTERINE®’s effectiveness in plaque and gingivitis control has been proven in numerous well controlled clinical studies. While LISTERINE® has not been studied or tested specifically on diabetics, the efficacy of LISTERINE® would not be expected to be different for this population. LISTERINE® is a sugar-free product that is sweetened with artificial sweeteners that are safe for diabetics. Furthermore, LISTERINE® is an expectorated product and is not intended for ingestion. People with diabetes, especially poorly controlled diabetes, can be expected to benefit from a regimen that includes the plaque and gingivitis control of LISTERINE®.
9. “I’m concerned that LISTERINE does not contain fluoride”
LISTERINE® is to be used in a regimen including brushing twice daily with a fluoride toothpaste, flossing once a day and rinsing twice each day for 30s with 20 mL of LISTERINE®. The role of LISTERINE® in the regimen is to kill germs that cause plaque, gingivitis, and bad breath, and therefore most LISTERINE® products do not contain fluoride. However, LISTERINE® Tooth Defense and the pediatric rinse LISTERINE Smart Rinse in the US, as well as LISTERINE Tooth and Gum Defense, and LISTERINE® Total Care in ex-US markets, all contain fluoride to strengthen teeth to help prevent cavities.
10. “Is LISTERINE® safe for patients with Xerostomia?”
The potential for LISTERINE® to cause oral irritation and drying in patients with xerostomia was evaluated in an exaggerated-use study in which subjects with clinically-documented xerostomia rinsed with 20 mL of LISTERINE® 3 times each day for 14 days. The oral mucosa of all subjects appeared normal at the 14-day examination, suggesting that the potential for oral irritation in a xerostomia population is minimal. In addition, rinsing with LISTERINE® was shown to temporarily increase the flow of saliva in subjects compared to a control rinse. These findings suggest that LISTERINE® can be safely recommended to patients with xerostomia.
Fishman, S.L. et al. Am. J. Dent., 17(1):23-6, 2004.
11. “My Muslim patients have a religious objection to the alcohol in LISTERINE®.”
Muslim patients may express concerns regarding using LISTERINE® due to religious objections to alcohol. Although LISTERINE® contains alcohol, LISTERINE® is a therapeutic, expectorated product and is not intended to be ingested. LISTERINE® contains denatured, pharmaceutical grade alcohol, which is not meant for consumption and would render a patient ill if ingested in large quantities. In addition, LISTERINE® is recommended by dental professionals in countries such as Indonesia and the UAE which have significant Muslim populations, and where other alcohol-containing products, such as cough syrup and perfume, have been adopted by Muslim communities.
12. “Should I recommend LISTERINE® to my alcoholic patients?”
Patients with alcohol abuse issues should consult an abuse counselor before using an alcohol-containing mouthrinse, such as LISTERINE®. In addition, patients taking disulfiram (Antabuse®) or metronidazone (Flagyl®) should not use LISTERINE®, as their combined use may cause unpleasant side effects, including nausea and vomiting.
DePaola LG , Spolarich AE. J Dent Hyg. 2007;Special supplement:13-25.
13. “I’m concerned about the safety of LISTERINE® with pregnant women.”
LISTERINE® is an expectorated product and is not ingested, so there is no reason pregnant women can not use LISTERINE® as directed. There have been no adverse events reported in pregnant women using LISTERINE®.
14. “My patients experience a burning sensation when rinsing with LISTERINE®.”
The intense sensation patients may experience while rinsing with LISTERINE® is due to the essential oil thymol, not alcohol, as is commonly believed. Many patients enjoy the intense flavor and feel it is “proof” that the product is working. Those who are looking for a less intense experience may try LISTERINE® Cool Citrus and new Total Care which are less intense than but equally as effective as the more traditional flavors such as the original LISTERINE® Antiseptic and Cool Mint. Alternatively, patients may also gradually transition to using the product by starting with shorter rinsing times at full strength and building to a full 30-seconds rinse, as directed.
15. “I’m concerned that the regular use of LISTERINE® may increase the risk of oral cancer.”
The pharmaceutical-grade alcohol in LISTERINE® is not an active ingredient, but rather serves as a solvent for the fixed combination of the essential oils thymol, menthol, eucalyptol and methyl salicylate. The alcohol also acts as a delivery vehicle for the essential oil actives, contributing to LISTERINE®’s superior plaque biofilm penetration.
It is commonly accepted that excessive consumption of alcoholic beverages can cause the development of oral cancer, especially when combined with smoking. This has led some professionals to speculate that there may be a link between using alcohol-containing rinses and an increased risk for oral cancer. A 2003 review of 9 epidemiological studies of oropharyngeal cancer and alcohol-containing mouthrinse use, including a re-analysis of an NCI study, revealed no causal link between the use of alcohol-containing rinses and oropharyngeal cancer.1
Ethanol is not a carcinogen; however, alcoholic beverages contain numerous carcinogenic compounds, such as urethane, nitrosamines, polycyclichydrocarbans and afflatoxins. Ethanol has been shown to increase the permeability of the oral mucosa after exposures of over one hour, which would allow for increased mucosal penetration of the carcinogens found in alcoholic beverages and tobacco products.2 However, this same study also demonstrated that prolonged exposure to LISTERINE® (2 minutes compared to the recommended 30seconds for everyday use) did not affect mucosal permeability. Furthermore, LISTERINE® does not contain any known carcinogens.
LISTERINE® is the most extensively tested mouthwash in the world, with over 30 clinical studies examining its safety and efficacy. It has been safely used by over one billion people for more than 100 years. There is no evidence for concern regarding its alcohol content.
1. Cole P et al. JADA. 2003 ;134 : 1079-1087.
2. Squier CA et al. J Oral Path. 1986 ; 15 : 276-279.
16. “I’m concerned that the alcohol in LISTERINE® may cause drying.”
It has been clinically demonstrated in both xerostomic and non-xerostomic populations that LISTERINE® Antiseptic does not cause drying of the oral mucosa. (See question 14 for more detail.)
1. Fishman, S.L. et al. Am. J. Dent., 17(1):23-6, 2004
2. Kerr, RA et al. Quintessence Int., 38(8) :41-48, 2007