A review of mechanical dental plaque control

Dec. 13, 2012
Dr. Joo H. Kim gives a detailed overview of the history of oral hygiene instruction and effective dental plaque control methods — both manual and mechanical toothbrushing options — based on documented studies.

Dental plaque is a host-associated biofilm. Biofilms are matrix-enclosed bacterial populations that are firmly adherent to each other and/or to the surface. They are not easily removed and consist of an estimated 400 to 1,000 species of bacteria. The products of biofilm bacteria are known to initiate a chain of reactions leading to host protection, and also to tissue destruction. Therefore, regular personal and professional plaque removal measures are important in maintaining oral health. Haffajee (1) demonstrated that meticulous supragingival plaque removal reduces inflammation and gingival crevicular fluid (GCF). This alters the subgingival environment and modifies both the quantity and composition of subgingival plaque.

The idea of personal oral hygiene is not new. The earliest record of personal oral hygiene in the form of chewstick dates back in the Chinese literature to about 1600 BC. (2) Also, Hippocrates (460-377 BC) commented on the importance of removing deposits from the tooth surfaces. (2) The first bristle toothbrush was introduced in the Western world in the sixteenth century. Many forms of personal oral hygiene include toothbrush, dentifrices, interdental cleaning devices, mouthrinses, etc.

Toothbrushing is the most commonly used measure in oral hygiene practice, but depending on cultural background, different devices (chewing sticks, chewing sponges, etc.) are being used as well. Frandsen (3) suggested that the outcome of toothbrushing is dependent on: the design of the brush, the skill of the individual using the brush, and the frequency and duration of brushing.

It is believed that the first toothbrush was made of hog’s bristles. Today, nearly all toothbrushes are made of synthetic materials such as nylon filaments and plastic handles. (4) During toothbrushing, the removal of dental plaque is achieved primarily through direct contact between the filaments of the toothbrush and the surfaces of the teeth and soft tissues. The features of an ideal manual toothbrush should include following: (5)

1. Handle size appropriate to age and dexterity

2. Head size appropriate to the size of the individual patient’s requirements

3. Use of end-rounded nylon or polyester filaments not larger than 0.23 mm (0.009 inches) in diameter

4. Use of soft filament configurations as defined by the acceptable international industry standards (ISO)

5. Filament patterns that enhance plaque removal in the proximal spaces and along the gumline

Multiple tufts of filaments, sometimes angled in different directions, are currently used. (6)This design facilitates more plaque removal in such difficult-to-reach areas when compared with flat-headed brushes. (7) Several studies have investigated differences in plaque removal between brushes with different handle designs. In such studies brushes with long, contoured handles appeared to remove more plaque than brushes with traditional handles. (8) Numerous manual toothbrushes are available on the market. There is still, however, insufficient evidence that one specific toothbrush design is superior to another. Thus, in the absence of this evidence, the best toothbrush continues to be one that is properly used by the patient. (6,9)

Various studies showed that most individuals only remove about 40% to 50% of plaque by toothbrushing. (6,10,11) The results of the studies indicate that most subjects are not effective brushers even though they brush once every day. There is no single oral hygiene method that is correct for all patients due to differences in the morphology of the dentition, oral health/disease status, and/or the individual’s manual dexterity. The ideal brushing technique is the one that allows complete plaque removal in the least possible time, without causing any damage to the tissues. (12) Different toothbrushing methods recommended include the following:

1. Bass technique: (13) This method emphasizes cleaning of the area directly beneath the gingival margin. Filament tips are directed into the sulcus at approximately 45degrees to the long axis of the tooth. The brush is moved in a back-and-forth direction using short strokes without disengaging the tips of the filaments from the sulci. The Bass technique is widely accepted as an effective method for removing plaque not only at the gingival margin, but also approximately 1 mm subgingivally. (14)

2. Stillman technique: (15) This method was designed for massage and stimulation of the gingiva as well as for cleaning the cervical areas of the teeth. The head of the brush is positioned in an oblique direction toward the apex, with the filaments placed partly in the gingival margin and partly on the tooth surface. Light pressure together with a vibratory (slight rotary) movement is then applied to the handle, while the filament tips are maintained in position on the tooth surface.

3. Charters technique: (16)This method was originally developed to increase cleansing effectiveness and gingival stimulation in the interproximal areas. The head of the brush is positioned in an oblique direction with the filament tips directed toward the occlusal or incisal surfaces. Light pressure is used to flex the filaments and gently force the tips into the interproximal embrassures. A vibratory (slight rotary) movement is then applied to the handle while the filament tips are maintained in position on the tooth surface. This method is particularly effective in cases with receded interdental papillae because the filament tips can easily penetrate the interdental space.

4. Modified Bass/Stillman technique: Each of these methods can be modified to add a roll stroke. The brush is positioned similarly to the Bass/Stillman technique. After activation of the brush head in a back-and-forth direction, the head of the brush is rolled over the gingiva and tooth in the occlusal direction, making it possible for some of the filaments to reach interdentally.

To date, no methods of toothbrushing have been shown to be clearly superior to others. In 1986, Frandsen (3) commented on this issue by stating: “Researchers have realized that improvement in oral hygiene is not as dependent upon the development of better brushing methods as upon improved performance by the persons using any one of the accepted methods.” As with methods of toothbrushing, there is no consensus of optimum frequency of toothbrushing. From a practical standpoint, it is generally recommended that patients brush their teeth at least twice daily, not only to remove plaque but also to apply fluoride through the use of a dentifrice in order to prevent caries. The duration of brushing is consistently correlated with the amount of plaque that is removed according to multiple studies. (17-22) One study showed optimum plaque-removing efficacy at two minutes using manual or electric toothbrushes. (22) Prevention of gingival inflammation is important because the inflammatory condition of soft tissues also favors plaque accumulation. (23,24) A proper level of oral hygiene theoretically is the extent of plaque removal that prevents gingivitis/periodontal disease and tooth decay in the individual patient.

For people who are not highly motivated to personal oral hygiene, or those who have difficulties in performing the hand brushing technique may benefit from using an electric toothbrush in both motivation and plaque removal. Since the 1980s, tremendous advances have been made in the technology of electrically powered toothbrushes. Various electric toothbrushes have been developed to improve the efficiency of plaque removal using increased filament velocity, brush stroke frequency, and various filament patterns and motions. The more recent designs apply rotary motion or oscillating/rotating motion with pulsation, or have brush heads that move at high frequencies. Results from various studies show enhanced plaque removal and gingival inflammation control in the proximal tooth surfaces in a shorter time than with manual toothbrushes.(5,17,22)

Despite the enhanced proximal tooth surface plaque control, an electric toothbrush does not replace the need for a specific interdental cleaning method. The proximal areas are defined as the visible spaces between teeth that are not under the contact area. In health these areas are small, although they may increase after periodontal attachment loss. The terms interproximal and interdental may be used interchangeably and refer to the area under and related to the contact point (European Workshop on Mechanical Plaque Control in 1999). The toothbrush does not reach the proximal surfaces of teeth as efficiently as it does for the facial, lingual, and occlusal aspects, nor does it reach into the interproximal area between adjacent teeth. Patients susceptible to gingivitis/periodontitis and/or dental caries are more pronounced and occur more frequently in interdental area. (25) Therefore, measures for interdental plaque control should be selected to complement plaque control by toothbrushing. (26,27) Similar to toothbrushes, factors such as the contour and consistency of gingival tissues, the size of the interproximal embrasure, tooth position and alignment, and the ability and motivation of the patient should be taken into consideration when recommending an interdental cleaning method. In subjects with normal gingival contours and embrasures, dental floss or tape is recommended. At sites where soft-tissue recession has become pronounced, flossing becomes progressively less effective. In this case an alternative method of either woodsticks or interdental brushes is recommended. A review on interdental cleaning methods concluded that all conventional devices are effective, but each method should be suited to a particular patient as well as a particular situation in the mouth. (28)

Toothbrushing has been associated with some side effects such as tooth abrasion and gingival recession. (29) Trauma to hard tissues leads to cervical abrasion of the tooth surface. These lesions have been associated with toothbrush stiffness, the method of brushing, and brushing frequency. Cervical tooth abrasion has a multifactorial etiology, but in most cases it is the consequence of toothbrushing due to an excessive pressure of the brush and an excessive number of toothbrushing episodes/time. Tooth wear has also been associated with toothbrush characteristics, especially related to the finishing and hardness of the filaments. (30) It has been stated that hard-tissue damage is mainly caused by the abrasives in the dentifrice, whereas lesions of the gingival tissues are caused by the toothbrush. (31,32) In many instances, tooth abrasion is found in combination with gingival recession. Whereas gingival recession is associated with different etiologic/risk factors — e.g., periodontal inflammation, smoking, gingival biotype, or repeated periodontal instrumentation — inadequate toothbrushing is probably the most significant one. (33)

Mechanical plaque control demands active participation of the individual subject, and therefore, the establishment of proper oral home care habits is a process that involves and depends on behavioral changes to a great extent. For effective behavioral changes, patients should recognize their oral health status and understand the role of their personal oral hygiene procedures in the prevention of caries and periodontal diseases.

Informing patients about the causal relationship that led to the disease process is important as it will encourage patients to take responsibility for their own oral health. Toothbrushing instruction for a patient involves teaching what, when, where, and how. In addition, instruction should also involve a description of specific toothbrushing methods, the grasp of the brush, the sequence and amount of brushing, the areas of limited access, and supplementary brushing for occlusal surfaces and the tongue. (4) If a patient prefers a specific oral hygiene strategy, the clinician can evaluate this and modify the technique to maximize effectiveness, rather than changing it. The simplest, least time-consuming procedures that will effectively remove bacterial plaque and maintain oral health should be recommended.

If oral hygiene motivation, information, and instruction are combined with professional tooth cleaning, the effect in terms of reduction of plaque levels and levels of gingival inflammation may persist even after six months. A systematic review concluded, based on studies ≥6 months of duration, that a single oral hygiene instruction describing the use of a mechanical toothbrush, in addition to a single professional oral prophylaxis provided at baseline, had a significant positive effect on the reduction of gingivitis. (34) Rylander and Lindhe have recommended that oral hygiene instruction be given during a series of visits, allowing the possibility of immediate feedback to the patient and reinforcement of the patient’s home care activities. (35)

Author bio
Dr. Joo H. Kim received his DDS from New York University College of Dentistry, where he was elected to membership in Omicron Kappa Upsilon (OKU), the National Dental Honor Society. Dr. Kim is currently a chief postgraduate periodontology resident at the SUNY Stony Brook School of Dental Medicine.

References

1. Haffajee AD, Smith C, Torresyap G, Thompson M, Guerrero D, Socransky SS. Efficacy of manual and powered toothbrushes (II). Effect on microbiological parameters. Journal of Clinical Periodontology 2001; 28:947-954.

2. Carranza F, Shklar G. Ancient India and China. In: History of Periodontology. London: Quintessence, 2003; 9-13.

3. Frandsen A. Mechanical oral hygiene practices. In: Löe, H. & Kleinman, D.V., eds. Dental Plaque Control Measures and Oral Hygiene Practices. Oxford, Washington DC: IRL Press, 1986; 93-116.

4. Wilkins EM. Oral infection control: toothbrushes and toothbrushing In: Clinical Practice of the Dental Hygienist. Philadelphia: Lippincott Williams & Wilkins, 1999; 350-369.

5. Egelberg J, Claffey N. Role of mechanical dental plaque removal in prevention and therapy of caries and periodontal diseases. Consensus Report of Group B. In: Lang, N.P., Attström, R. & Löe, H., eds. Proceedings of the European Workshop on Mechanical Plaque Control. London: Quintessence, 1998; 169-172.

6. Jepsen S. The role of manual toothbrushes in effective plaque control: advantages and limitations. In: Lang, N.P., Attström, R. & Löe, H., eds. Proceedings of the European Workshop on Mechanical Plaque Control. London: Quintessence, 1998; 121-137.

7. Cugini M, Warren PR. The Oral-B CrossAction manual toothbrush: A 5-year literature review. Journal of the Canadian Dental Association, 2006; 72, 323.

8. Saxer UP, Yankel SL. Impact of improved toothbrushes on dental diseases I. Quintessence International 1997; 28:513-525.

9. Cancro LP, Fischman SL. The expected effect on oral health of dental plaque control through mechanical removal. Periodontology 2000, 1995; 8:60-74.

10. De la Rosa M, Zacarias Guerra J, Johnston DA, Radike AW. Plaque growth and removal with daily toothbrushing. Journal of Periodontology, 1979; 50:660-664.

11. Van der Weijden GA, Timmerman MF, Danser MM, van der Velden U. Relationship between the plaque removal efficacy of a manual toothbrush and brushing force. Journal of Clinical Periodontology 1998a; 25:413-416.

12. Hansen F, Gjermo P. The plaque-removal effect of four toothbrushing methods. Scandinavian Journal of Dental Research, 1971; 79:502-506.

13. Bass CC. The optimum characteristics of toothbrushes for personal oral hygiene. Dental Items of Interest, 1948; 70:696.

14. Waerhaug J. Effect of toothbrushing on subgingival plaque formation. Journal of Periodontology, 1981a; 52:30-34.

15. Stillman PR. A philosophy of treatment of periodontal disease. Dental Digest, 1932; 38:315-322.

16. Charters WJ. Home care of the mouth. I. Proper home care of the mouth. Journal of Periodontology, 1948; 19:136.

17. Van der Weijden GA, Timmerman MF, Snoek CM, Reijerse E, van der Velden U. Toothbrushing duration and plaque removal efficacy of electric toothbrushes. American Journal of Dentistry, 1996a; 9:31-36.

18. McCracken GI, Janssen J, Swan M, Steen N, de Jager M, Heasman PA. Effect of brushing force and time on plaque removal using a powered toothbrush. Journal of Clinical Periodontology, 2003; 30:409-413.

19. McCracken GI, Steen N, Preshaw PM, Heasman L, Stacey F, Heasman PA. The crossover design to evaluate the efficacy of plaque removal in toothbrushing studies. Journal of Clinical Periodontology, 2005; 32:1157-1162.

20. Preber H, Ylipää V, Bergstrom J, Ryden H. A comparative study of plaque removing efficiency using rotary electric and manual toothbrushes. Swedish Dental Journal, 1991; 15:229-234.

21. Hawkins BF, Kohout FJ, Lainson PA, Heckert A. Duration of toothbrushing for effective plaque control. Quintessence International, 1986; 17:361-365.

22. Van der Weijden GA, Timmerman MF, Nijboer A, Lie MA, van der Velden U. A comparative study of electric toothbrushes for the effectiveness of plaque removal in relation to toothbrushing duration. Journal of Clinical Periodontology, 1993; 20:476-481.

23. Ramberg P, Lindhe J, Dahlen G, Volpe AR. The influence of gingival inflammation on de novo plaque formation. Journal of Clinical Periodontology, 1994; 21:51-56.

24. Rowshani B, Timmerman MF, van der Velden U. Plaque development in relation to the periodontal condition and bacterial load of the saliva. Journal of Clinical Periodontology, 2004; 31:214-218.

25. Löe H. Mechanical and chemical control of dental plaque. Journal of Clinical Periodontology, 1979; 6:32-36.

26. Lang NP, Cummings BR, Löe HA. Oral hygiene and gingival health in Danish dental students and faculty. Community Dentistry and Oral Epidemiology, 1977; 5:237-242.

27. Hugoson A, Koch G. Oral health in 1,000 individuals aged 3–70 years in the Community of Jönköping, Sweden. Swedish Dental Journal, 1979; 3:69-87.

28. Warren PR, Chater BV. An overview of established interdental cleaning methods. Journal of Clinical Dentistry, 1996a; 7(3):65-69.

29. Kitchin P. The prevalence of tooth root exposure and the relation of the extent of such exposure to the degree of abrasion in different age classes. Journal of Dental Research, 1941; 20:565-581.

30. Fishman SL. The history of oral hygiene products: How far have we come in 6000 years? Periodontology 2000, 1997; 15:7-14.

31. Axelsson P, Kocher T, Vivien N. Adverse effects of toothpastes on teeth, gingiva, and buccal mucosa. In: Lang, N.P., Karring, T. & Lindhe, J. eds. Proceedings of the 2nd European Workshop on Periodontology. Chemicals in Periodontics. London: Quintessence, 1997; 259-261.

32. Meyers IA, McQueen MJ, Harbrow D, Seymour GJ. The surface effect of dentifrices. Australian Dental Journal, 2000; 45:118-124.

33. Björn AL, Andersson U, Olsson A. Gingival recession in 15-year-old pupils. Swedish Dental Journal, 1981; 5:141-146.

34. Van der Weijden GA, Hioe KPA. Systematic review of the effectiveness of self-performed mechanical plaque removal in adults with gingivitis using a manual toothbrush. Journal of Clinical Periodontology, 2005; 32:214-228.

35. Rylander H, Lindhe J. Cause-related periodontal therapy. In: Lindhe, J., Karring, T. & Lang, N.P., eds. Clinical Periodontology and Implant Dentistry. Copenhagen: Munksgaard, 1997; 438-447.