Form and Function in Toothbrushes
How design developments affect your patients’ oral hygiene routines
Ahmed Hassan, BDSc (DH); and Shirley Gutkowski, RDH, BSDH
Although the early form of the toothbrush has been in existence for 7,000 years, the importance of maintaining good oral hygiene has escalated within the past few decades, based on the discovery that poor oral hygiene may result in serious health concerns such as diabetes, fetal problems in pregnant women, premature birth, heart disease, and premature death in some cases.1 Understanding the features of toothbrushes and how they work can help patients maintain oral hygiene in a proper and effective manner.
The texture and design of modern toothbrushes are not simply to attract consumers: the variety of bristle, head, and handle shapes are created to assist the user in simpler and more effective plaque removal. A comparison of different types of toothbrushes reveals the importance of the design in maintaining oral hygiene.
Toothbrushes typically consist of three parts:
• head: the working end that holds the bristles or filament
• handle: the part grasped by the hand during brushing
• shank: the section that connects the head to the handle
The head size of a toothbrush can range from 0.5 inches to 1.5 inches, giving individuals the option to choose a comfortable size to fit the mouth. The American Dental Association (ADA) guidance for head size recommends 1.25 inches in length, 2 to 4 rows of bristles, 5/16 to 3/8 inches in width, and 5 to 12 tufts/row.2
Conventional toothbrush heads are rectangular, designed to clean the surface of each tooth effectively. Diamond-shaped toothbrush heads are slightly narrower at the tip to help reach the distal surfaces of posterior teeth. Deep-grooved designs allow the user to position the bristles correctly at a 45º angle, assuring the most effective means of plaque control.
Bristle patterns vary as well, including:
• block: all the bristles the same length and aligned neatly
• wavy or v-shaped (ripple-shaped): designed to offer better access to all areas around the tooth surface
• multilevel trim pattern: helps to clean difficult areas between teeth and on the crown
• criss-cross pattern with rubber bristles on the sides: helps to lift plaque effectively
• polishing: multilevel bristles and rubber-like circles at the center help to clean supra-gingival plaque3
Researchers found that bristle shape had little effect on the plaque removal capacity of a toothbrush.4 In addition, when a standard brush head design was compared with two flexible-head toothbrushes, no differences were found in plaque removal.5
Finally, multiple options exist for the design of the handle, including:
• straight: traditional handles that are easier to control
• contra-angle: similar to a dental instrument, improves ergonomics for the user and provides better access to difficult-to-clean areas
• flexible: reduces excessive brushing force
• slip prevention: helps to maintain hold
Some of the most innovative developments in oral hygiene recently are in power toothbrushes, powered through either disposable batteries or rechargeable sources. Rechargeable toothbrushes are typically more expensive, and their speed varies depending upon the model and manufacturer.
Power toothbrushes are classified as:
• circular/rotary: entire head rotates in a full circle, in one direction only
• counter oscillation: adjacent tufts rotate in opposite directions from one another
• multidirectional: stationary and moving tuft fields combine with a moving head to provide triple-zone cleaning
• oscillating rotating: rotates in one direction once, then in the other
• oscillating rotating pulsating: complete rotation and pulsation
• sonic: head rotates laterally
• ultrasonic: bristle vibrates
An additional, lesser-known option is the ionic toothbrush. The mechanism for the ionic action is due to a change in the polarity of the teeth. Active ionic toothbrushes are reported to reduce 82% of plaque and 97% of bleeding index compared with inactive ionic toothbrushes.6
In general, power toothbrush heads are smaller than manual ones, and there are often multiple brush head options, either fixed or replaceable. The basic power toothbrush uses either reciprocating (back and forth), accurate (up and down), or elliptical (combination) movement. The bristles are arranged like those of a manual toothbrush or mounted in a circular pattern to facilitate rotating motion.
Some power models have special features, such as timers, displays, pressure sensors, or Bluetooth. Timers either turn off after 2 minutes or give an indication to change quadrants after 30 seconds. Displayed icons such as smiling faces encourage compliance. Some models also sense the pressure applied against the tooth to prevent aggressive brushing that may harm the periodontium and tooth structure.
Basic recommendations for using a power toothbrush are to position it at a 45-degree angle to the tooth surface and 90 degrees to the incisal plane, with optimal pressure, while brushing for 2 minutes twice a day.
Regarding clinical differences among the different models, some studies have indicated that electric toothbrushes are 11% more effective in plaque reduction than manual toothbrushing.7 One study showed that electric toothbrushes provide plaque reduction up to 131% for the whole mouth, 97.4% at the gum line, and 220% interproximally, and that they can reduce gingivitis up to 400% and gingivitis severity up to 320% after 12 weeks of use (when compared with manual flat-trim toothbrushes).7 However, other studies have found no difference in plaque-removing efficacy between electric and manual toothbrushes.8,9 Ruchi et al found manual and electric toothbrushes to be equally effective in controlling plaque, gingivitis, and interdental bleeding in patients undergoing fixed orthodontic treatment.10
Abrasion is multifactorial, but is generally believed to be caused by overzealous toothbrushing. Higher force results in more significant abrasion. Joshi et al concluded that toothbrushes with soft bristle hardness at 1.8 N or beyond cause significantly more abrasion than those with medium bristle hardness.11 Bizhang et al compared toothbrush abrasivity and ranked flat-trim, rippled-shaped manual toothbrushes as the least abrasive to human dentin.12 De Boer et al found that toothpaste abrasion is correlated with the number of strokes: a medium toothbrush is 1.4 times more abrasive when compared with a soft toothbrush, and the larger-size particles are more abrasive.13
In conclusion, an impressive range of toothbrush designs and features have been developed to meet patients' needs. Evidence indicates that everything from miswak chewing sticks to advanced smart toothbrushes can prove to be viable options for a strong oral hygiene routine.
About the Authors
Ahmed Hassan, BSDCP (DH), is a Research Associate (Independent Researcher), author, and public speaker who earned an academic gold medal in his undergraduate program at Dow University of Health and Sciences. Shirley Gutkowski, RDH, BSDH, is an orofacial myofunctional therapist and Buteyko breathing educator in Sun Prairie, WI.
1. Jeffcoat MK, Geurs NC, Reddy MS, et al. Periodontal infection and preterm birth: results of a prospective study. J Am Dent Assoc. 2001;132(7):875-880.
2. Harris NO, Garcia-Godoy F. Primary Preventive Dentistry. 6th ed. Upper Saddle River, NJ: Pearson Education; 2004.
3. Patil SS, Rakhewar PS, Limaye PS, Chaudhari NP. A comparative evaluation of plaque-removing efficacy of air polishing and rubber-cup, bristle brush with paste polishing on oral hygiene status: A clinical study. J Int Soc Prev Community Dent.2015;5(6):457-462.
4. Cifcibasi E, Koyuncuoglu CZ, Baser U, et al. Comparison of manual toothbrushes with different bristle designs in terms of cleaning efficacy and potential role on gingival recession. Eur J Dent. 2014;8(3):395-401.
5. Warren DP, Rice HC, Turner S. Comparison of plaque removing ability of one standard and two flexible-head toothbrushes. J Dent Hyg. 2004;78(2):340-342.
6. Deshmukh J, Vandana KL, Chandrashekar KT, Savitha B. Clinical evaluation of an ionic tooth brush on oral hygiene status, gingival status, and microbial parameter. Indian J Dent Res. 2006;17(2):74-77.
7. Yaacob M, Worthington HV, Deacon SA, et al. Powered versus manual toothbrushing for oral health. Cochrane Database Syst Rev. 2014;6:CD002281.
8. Neelima M, Chandrashekar BR, Goel S, et al. "Is powered toothbrush better than manual toothbrush in removing dental plaque?" - A crossover randomized double-blind study among differently abled, India. J Indian Soc Periodontol. 2017;21(2):138-143.
9. Vibhute A, Vandana KL. The effectiveness of manual versus powered toothbrushes for plaque removal and gingival health: A meta-analysis. J Indian Soc Periodontol.2012;16(2):156-160.
10. Sharma R, Trehan M, Sharma S, et al. Comparison of effectiveness of manual orthodontic, powered and sonic toothbrushes on oral hygiene of fixed orthodontic patients. Int J Clin Pediatr Dent. 2015;8(3):181-189.
11. Joshi CP, Patil AG, Karde PA, et al. Comparative evaluation of cemental abrasion caused by soft and medium bristle hardness toothbrushes at three predetermined toothbrushing forces: An in vitro study. J Indian Soc Periodontol.2017;21(1):10-15.
12. Bizhang M, Schmidt I, Chun YP, et al. Toothbrush abrasivity in a long-term simulation on human dentin depends on brushing mode and bristle arrangement. PLoS One. 2017;12(2):e0172060.
13. De Boer P, Duinkerke AS, Arends J. Influence of tooth paste particle size and tooth brush stiffness on dentine abrasion in vitro. Caries Res. 1985;19(3):232-239.
Rinses and Flosses: The Latest Trends
As toothbrush technology continues to evolve, manufacturers of oral hygiene products also are developing innovative new rinse and floss products, with the goal of helping patients practice the most efficient, effective daily hygiene routines possible.
The ADA categorizes oral rinses, or mouthwash, as primarily either cosmetic or therapeutic. Cosmetic mouthwash typically combats bad breath, while therapeutic rinses-available either over the counter or by prescription-help reduce or control plaque, gingivitis, and tooth decay as well.1
Active ingredients that may be used in therapeutic mouthwash include cetylpyridinium chloride (to reduce bad breath), chlorhexidine or essential oils (to control plaque and gingivitis), fluoride (to prevent decay), and peroxide (to whiten teeth).1
A recent study found that chlorhexidine, antioxidant, and hyaluronic acid mouthwashes all significantly reduced plaque scores, with chlorhexidine having the highest effect.2 All three types significantly reduced the total bleeding scores, and teeth underwent shade changes in association with all three interventions by the end of the study.2 Participants reported preferring the hyaluronic acid mouthwashes.2
Several rinses are marketed as "eco-friendly" and even "vegan-friendly," utilizing essential oils and other all-natural ingredients.
Another current trend is charcoal-based mouthwash, which is touted as taking advantage of charcoal's porous and absorbent qualities,3 and offering antimicrobial activity, anti-halitosis, tooth whitening, periodontal disease control, caries reduction, and tooth remineralization, among other benefits.4 However, a recent study notes insufficient evidence to substantiate these claims, and no available information on charcoal particulate size or abrasivity of any of these products.4
Some rinses are used to treat xerostomia. One formula utilizes the restorative benefits of Chitosan with the pH-balancing properties of Arginine. Alcohol-free and sugar-free options are available.
The ADA says the use of an interdental cleaner, such as floss, is an essential part of taking care of your teeth and gums.5 It is usually made from nylon filaments or plastic monofilaments and is often treated with flavoring agents such as mint.5 There is no difference in the effectiveness of waxed or unwaxed flosses.5
One study evaluated the plaque-removal efficacy of three traditional (unwaxed, woven, and shred-resistant) products and one powered flosser and found that all four in combination with a manual toothbrush removed plaque significantly better than the toothbrush alone.6 Among floss types, there was evidence of superiority for the powered flosser but no significant treatment differences between the three traditional products.6
Meanwhile, another study found fluoridated toothpicks to provide slightly more mineral gain and somewhat less lesion depth in dentine than non-fluoridated floss.7
1. Oral Health Topics: Mouthwash (Mouthrinse). ADA website. https://www.ada.org/en/member-center/oral-health-topics/mouthrinse. Updated August 29, 2019. Accessed March 12, 2020.
2. Abdulkareem AA et al. A randomized double-blind clinical trial to evaluate the efficacy of chlorhexidine, antioxidant, and hyaluronic acid mouthwashes in the management of biofilm-induced gingivitis [published online ahead of print February 26, 2020]. Int J Dent Hyg. doi: 10.1111/idh.12432.
3. Gregson C. What are the benefits of rinsing with activated charcoal mouthwash? Hello Products website. https://www.hello-products.com/friendly-blog/activated-charcoal-mouthwash-benefits/. Published May 21, 2019. Accessed March 12, 2020.
4. Brooks JK, Bashirelahi N, Hsia RC, Reynolds MA. Charcoal-based mouthwashes: a literature review. Br Dent J. 2020;228(4):290-4.
5. Oral Health Topics: Floss/Interdental Cleaners. ADA website. https://www.ada.org/en/member-center/oral-health-topics/floss. Updated March 25, 2019. Accessed March 12, 2020.
6. Terézalmy GT, Bartizek RD, Biesbrock AR. Plaque-removal efficacy of four types of dental floss. J Periodontol. 2008;79(2):245-51.
7. Särner B et al. Effect of fluoridated toothpicks and dental flosses on enamel and dentine and on plaque composition in situ. Caries Res. 2005;39(1):52-9.