A review of Mechanical Dental Plaque Control

 Various studies showed that most individuals only remove about 40% to 50% of plaque by toothbrushing. 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. Different toothbrushing methods recommended include the following:

1. Bass technique: This method emphasizes cleaning of the area directly beneath the gingival margin. Filament tips are directed into the sulcus at approximately 45 degrees 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.

2. Stillman technique: 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: 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 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. One study showed optimum plaque-removing efficacy at two minutes using manual or electric toothbrushes. Prevention of gingival inflammation is important because the inflammatory condition of soft tissues also favors plaque accumulation. 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.

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. Therefore, measures for interdental plaque control should be selected to complement plaque control by toothbrushing. 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.

Toothbrushing has been associated with some side effects such as tooth abrasion and gingival recession. 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. 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. 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.

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. 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.