With so may choices of toothpastes on the market, patients often ask, “What type of toothpaste should I be using to clean my teeth?” This is a loaded question. In order to properly answer this question, we must consider the following discussion below.
The first and foremost goal of any toothpaste is to promote oral hygiene. Most toothpastes contain abrasive aids to remove plaque (bacteria) debris and food from accumulating on your teeth and gums, ultimately helping to reduce gum diseases (gingivitis & periodontitis). Additionally, most tooth pastes contain fluoride to help prevent tooth decay (dental caries).
How Abrasive is your Toothpaste: Relative Dentin Abrasivity Value (RDA)?
In 1970, the American Dental Association (ADA) began creating a standardized system for measuring the abrasiveness of toothpastes that were on the market relative to a standardized control sample. They assigned their control paste, calcium pyrophosphate, a value of 100 on their Relative Dentin Abrasivity (RDA) scale.4 The higher the RDA number, the more abrasive the toothpaste. (Table 1)
The FDA supported these studies and deemed that no toothpaste should exceed 2.5 times the abrasiveness of the control standard, or an RDA value of 250. Since studies at the time showed that 80 to 90 percent of extrinsic stains could be removed with a toothpaste of an RDA between 100 and 200, this seemed reasonable.5 Their upper limit of an RDA value of 250 was based on research that showed that lab-simulated brushing with such a toothpaste would cause 1mm of dentin (second layer of tooth under enamel)wear after 100,000 strokes – what they deemed a lifetime of a brushing, and an acceptable loss of tooth structure.6
While the ADA webpage on toothpastes states that the RDA scale “should not be used to rank the safety of dentifrices with RDA values below 250” and that “these values do not correspond to potential clinical effects, like abrasion,” some studies have shown that there is a direct correlation between the RDA value of a toothpaste and the amount of abraded dentin.7,8
CAUTION: Toothpaste manufacturers regularly measure their product’s abrasivity. It is not necessary to obtain FDA approval, and it is usually not required to be disclosed on the product label.
The second goal of a toothpaste is that it should not damage your teeth and gums. There are several ways that we can damage our teeth and gums. According to the literature, repeated acid exposure, for example drinking acidic drinks (low PH values) can cause erosion (wearing away of tooth structure by chemical means) of your teeth. Furthermore, using abrasive toothpastes with an incorrect brushing technique could cause abrasion (wearing away of tooth structure by mechanical means). As the enamel is softened from the repeated acid exposure, it becomes more prone to abrasion when patients attempt to brush their teeth.
The repeated acid exposure (whether dietary or due to dental products), combined with abrasive and flexural forces (grinding teeth movement) on the teeth may lead to exposed gums and roots causing the formation of non-carious cervical lesions(1,2,3). These non-carious cervical lesions can be seen as V-shaped notches on the necks of teeth (Figure 1).
LOSS OF TOOTH STRUCTURE & GUM RECESSION
The correlation between gum recession (exposed root surfaces) and the abrasion of the resulting exposed root surfaces has been documented.9 These can often be seen as cervical notches on the necks of the teeth (Figure 2). The question we have to ask ourselves is, what is the cause of cervical abrasion? Is it the toothpaste, toothbrush or both? The answer is not so straightforward due to many confounding factors to consider such as brushing technique, brushing force, brushing frequency, brushing time, type of brush, and bristle stiffness. The majority of studies conducted suggest that soft, medium or hard brushes did not damage tooth structure when used with water as the control. However, when toothpaste was added to the studies, cervical abrasion was observed on the teeth9.
DENTAL IMPLICATIONS FOR PATIENTS
By listening to and asking patients about their dietary and beverage habits, one may find a positive relationship between the frequency of acidic exposures (acidic foods, soda, carbonic beverages etc.) and the wearing away of their tooth structure. Many times patients are often completely unaware of the acid reflux, while remembering that some reflux is “silent” and does not present with typical symptoms of acid indigestion, bloating, and stomach pain. If a patient has any of the above signs and or symptoms, a referral to a physician or gastroenterologist should be given for further evaluation with an endoscopic evaluation of the esophagus. This type of exam can literally save a life by looking for changes to the lining of the esophagus, termed “Barrett’s Esophagus”, which is often associated with an increased risk of cancer.
TMJ & Bite Analysis
If a thorough Temporo-Mandibular Joint (TMJ) and a Occlusal (Bite) analysis reveal abnormal pain involving the TMJ or there is obvious wear of the of teeth or cervical lesions, one approach is to fabricate an occlusal (bite) guard fabricated to wear at night to protect against undue bite forces. These bite forces can be damaging to the both the teeth and gums and could accelerate the loss of tooth wear and gum recession. A properly constructed occlusal bite guard is done by the use of a centric related bite record and with a leaf guage (Figure 3) to capture the joint position of the patient (Figure 4). Once this is completed, the appropriate type of occlusal appliance can be designed, fabricated and customized to fit the patient (Figures 5,6). There is not a “one size ” fits all when prescribing the appropriate bite guard. A careful diagnosis is made so that the appropriate guard is chosen to meet the specific requirements of the patient.
Gum recession (exposed root surfaces) could be accelerated by using an improper brushing technique, an abrasive toothpaste, as well as a grinding habit. Many times the gum recession can be corrected by using a minimally invasive microsurgical approach(Figures 7,8), however the long-term success of the gum grafting procedure will depend on the management of oral hygiene, dietary intake and bite forces.
PRESTIPINO & SFONDOURIS RECOMMEDATIONS
Given that there are many variables to consider when choosing a toothpaste, we recommend using the softest toothpaste that allows patients to manage their stain levels over 3-6 month periods between cleanings. For most people, that may mean an RDA value around 0-1000. The next time you go to the store to buy your toothpaste, review this list (Table 1) and see which toothpaste may not be Too Hard on Your Teeth and Gums!
Information about the Author: Dr. Tassos Sfondouris is a board certified periodontist and restorative dentist. He is a clinical research associate at at the National Institute of Health. He is passionate about periodontal and restorative therapies that promote the health, comfort, and function of teeth. He welcomes your comments and encourages you to like him on Facebook or follow him on Twitter to get the latest unbiased information on pertinent dental health topics.
- Grippo JO, Chaiyabutr Y, Kois JC. Effects of Cyclic Fatigue Stress-Biocorrosion on Noncarious Cervical Lesions. Journal of Esthetic and Restorative Dentistry. 2013:25(4):265-272.
- West N, Hooper S, Osullivan D, et al. In situ randomized trial investigating abrasive effects of two desensitizing toothpastes on dentine with acidic challenge prior to brushing. Journal of Dentistry. 2012;40(1):77-85
- Abrasivity of Current Dentifrices. The Journal of the American Dental Association. 1970;81(5):1177-1178.
- Kitchin PC, Robinson HB. How Abrasive Need a Dentifrice Be? Journal of Dental Research. 1948;27(4):501-506.
- John, Samuel & White, Donald. (2015). History of the Development of Abrasivity Limits for Dentifrices. The Journal of Clinical Dentistry. 2015: 26(02). 50-4.
- Oral Health Topics- Toothpastes. Toothpastes. http://www.ada.org/en/member-center/oral-health-topics/toothpastes. Accessed October 29, 2017.
- Wiegand A, Kuhn M, Sener B, Roos M, Attin T. Abrasion of eroded dentin caused by toothpaste slurries of different abrasivity and toothbrushes of different filament diameter. Journal of Dentistry. 2009;37(6):480-484.
- Ervin JC, Bucher EM. Prevalence of tooth root ecposure and abrasion among dental patnets. Dent items Interest 1944;66:760-9.