Mechanical Plaque Control
by Dinh X. Bui, D.D.S., M.S.

Mechanical Plaque Control
Mechanical plaque control, as measured by the oral hygiene effort of the individual patient, is the most important predictive factor in determining the overall prognosis of the treatment therapy. It is very critical in every phase of therapy that plaque control must be maintained and preferrably with plaque free result. It is an effective way of treating and preventing gingivitis, periodontitis, and perhaps any microbial etiology disease as related to oral health. It is a key element of the practice of dentistry. Good plaque control predicts success for any treatment therapy and greatly influenced the patient ability to preserve his or her dentition in the state of life long health. There are two mode of plaque control, mechanical and chemical. This paper deals strictly with the topic of mechanical plaque control, the rationale, and the role of mechanical plaque control in periodontal therapy.

Mechanical plaque control is the removal of microbial plaque and the prevention of accumulation on the teeth and adjacent gingival surface by the use of tooth brush and other mechanical hygiene aids without the use of chemical. The role of microbial plaque in the etiology of gingivitis and periodontal disease have been demonstrated by Loe study and others. The removal of microbial plaque leads to cessation of gingival inflammation, and cessation of plaque control measure leads to recurrence of inflammation. The removal of plaque also decreased the rate of formation of calculus. Thus eliminating the plaque is the key to prevent the occurence of periodontal disease or halting the progression of the disease. The objective of mechanical plaque control therapy is the complete daily removal of dental plaque with a minimum of effort, time, and devices, using the simplest methods possible. The patient’s plaque control procedures must be modified as changes occur in the soft tissue anatomy following periodontal surgery in order to be effective. The dentist must be able to forsee these changes and offer the available oral hygiene device suitable to maintain excellent plaque control continuously throughout the therapy and into the later years.

In the old time, tooth brush are usually large, made of wood, and generally inaccessible to many areas intraorally. The bristle tooth brush appeared about the year of 1600 in China and later was patented in America in 1857. Originally, they are varied in size, length, hardness of the bristle, and even in the arrangement of the bristle. The bristle type has undergone major change from being made out of hogs bristles to nylon. Nylon is superior to the counterpart in term of homogeneity of the material, uniformity of bristle size, elasticity, resistance to fracture, and repulsion of water and debris, and asepsis. Natural hog bristles are more susceptible to fraying, breaking, contamination with diluted microbial debris, softening, and loss of elasticity. Parfitt in 1963 reported that the toothbrush chosen by the patient under recommendation of the dentist was usually too hard or stiff. The hard brisle brush can cause trauma to soft tissue, abrasion to root surface which exposed following gingival recession, and also inability to clean interproximally due to poor adaptation to the contour of anatomical structure. Tissue trauma includes bleeding, burning and blistering of the epithelium, and most importantly, causing the patient to withdraw from brushing in the traumatic area. The terminal teeth, particularly the distal surfaces are difficult to reach with the tooth brush and thus harbor debris. The same is true with the lingual of mandibular anterior and the palatal surface of upper teeth as the result of lack of adaptation of the tooth brush bristle to the contour ot the arch. There are also different type of bristle arrangements and bristle type: the multitufted tooth brush which contain more bristle, the round bristle ends cause fewer scratch on the gingiva, the angle cut bristle which allowed to reach into the interproximal spaces and irregular contour to the tooth surface. The handle designs also are available in straight and contraangle. The size of the brush head is also varied from different manufacturers. The American Denatl Association has described a range of dimension of acceptable brushes: these have a brushing surface from 1 to 1.25 inches long and 5/16 to 3/8 inch wide, two to four row of bristle, and 5 to 12 tufted per row. The toothbrush should be able to reach and efficiently clean most areas of the teeth. Bass recommended the soft bristle, straight handle type of brush. The dimensionfor this soft bristle is .007 inch in diameter and .406 inch in lenght, with rounded ends, arranged in three row of tufts, six evenly space tufts per row, with 80 to 86 bristles per tuft. For children, the brush is smaller, with thinner .005 inch and shorter .344 inch bristle. The use of soft toothbrush eliminates gingival recession, tooth surface abrasion (classical wedge shape defect in the cervical area of root surfaces), trauma to soft tissue. Soft brisle are more flexible, clean beneath the gingival margin, and reach farther into the proximal tooth surfaces. There are no significant difference in straight or contraangle handle in term of cleaning effectiveness. There is no specific toothbrush can be singled out as clearly superior for the routine removal of microbial deposits from the teeth.

To maintain cleaning effectiveness, tooth brush should be replaced when bristle head show fraying, or brush head demonstrated any kind of bacterial contamination or wear patterns. Most brushes wear out in about 3 months. Many manufacturer introduced the wear indicator dye, of which the fading of the dye due to mechanical wear indicating the time to change the tooth brush. Nevertheless, the rule of thumb is that the patient should change the brush when he or she felt the brush is inadequate in carried out normal oral hygiene effort, resulting in compromising cleaning effectiveness.

Today, there are three methods that are widely accepted: the bass method, the modified stillman method, and the charters method . Controlled studied evaluating the most common brushing technique have shown that no one method is clearly superior. Dentist should be noted that a plaque control devices should be tailored to the individual, similarly to his or her plaque control program. The bass method involved placing the brush head parallel with the occlusal plane, with the brush head covering three teeth, beginning at the most distal tooth in the arch, bristle at the gingival margin, establishing an angle of 45 degree to the long axis of the teeth, then exerting the genral vibratory pressure using the short back and forth motions without dislodging the tips of the bristles during brushing. Patient should feel the bristle ends in the sulci, as well as the interproximal embrasure and should produce perceptible blanching of gingiva. Patient should complete 20 strokes in the same position. The brush then is moved anteriorly, covering the next three teeth. To reach the lingual surface fo mandibular anterior teeth, insert the brush vertically and press the heel of brush into the gingival sulci and proximal surfaces at 45 degree angel to the long axis of the teeth. Give it 20 strokes. The reach the distal surfaces of the last tooth, open the mouth wide and vibrate the tip of the brush against that surface, 20 times for each tooth. The movement should be short, covering 3 teeth. The angle should be 45 degree, placing the bristle into the gingival sulci, elbow hold as far out as necessary, and the bristle are press directly into the sulci. The advantage of the Bass method included 1) the back and forth motion is easy to master because it requires simple movement and 2)it concentrates the cleaning action on the cervical and interproximal portions of the teeth, where microbial plaque is most detrimental to the gingiva. It can be recommended to patient with or without periodontal involvement. The modified Bass technique involved an extra step. At the end of the vibratory motions, the bristles are swept toward the occlusal surface of the tooth, cleaning the remaining facial and lingual surfaces of the tooth.

Another method of brushing is the modified Stillman method. The brush should be placed with the bristle end resting partly on the cervical portion of the teeth and partly on the gingiva, with the sides of the bristle are pressed against the teeth and gingiva while moving the brush with short back and forth strokes in a coronal direction. With this technique, the sides rather than the end of the bristles are used, and penetration of the bristles into the gingival sulci is avoided. The modified Stillman method may be recommended for cleaning in the areas with progressive gingival recession and root exposure to prevent abrasive tissue destruction.

Finally, the Charters method involves placing the brush on the tooth with the bristles pointed toward the crown at the 45 degree angle to the long axis of the teeth (directly opposite to the bass technique). The side of the brisles are flexed against the gingiva, and the back and forth motion is used to massage th gingiva. The bristle tips should not move across the gingiva. This method is especially suitable for gentle plaque removal and gingival massage. When using a soft brush, this technique can be recommended for temporary cleaning in the areas of healing wounds after periodontal surgery.

Other technique noteworthy to be mentioned are the Fones’ technique and the roll technique. The Fones’ technique is for young children who cannot master all the complicated movement. The teeth are in occlusion and the brush is pressed rather vigorously against the teeth and gums and revolved in circles as large a diameter as possible. This technique is not used in periodontal pateint since it does not adequately engage interproximal area. The roll technique is performed when patient has normal oral health. The bristles are placed well up on the gingiva at 45 degree angle, the side of the bristle are pressed against the tissue and simultaneously rolled incisally or occlusally against the gingiva and teeth, similar to the turning of the latchkey.

O’Leary in 1970 studied the deposition of particlulate matter in the crevicular tissue by toothbrushing using the roll and the bass technique. Brushes presoaked in solution containing carbon particle were used. The result showed that no carbon particles were observed in the crevicular epithelium or underlying connective tissue of any test section on either technique. However, the result of this study does not eliminate the possibility that bacteria can be introduced into the crevicular tissue since the bacteria is smaller in size than the carbon particle used in this study.

Today, electric toothbrush has become increasingly popular. There are three types: the rotary brush, the sonic techology, and the ultrasonic technology. Up todate, there are two common sonic technology in the market are the sonicare and the sensonic (Teledyne). Sonic technology depicted the vibration of the brush head up to 20,000RPM, whereas the ultrasonic is from 25,000 RPM or above. There are currently no study which compared the efficiency of two brushes. The efficiency of the traditional rotary brush has been evaluated. Long and Killoy in 1985 evaluated the effectiveness of the Interplak versus manual toothbrushing using modified Bass technique in 14 orthodontic patients. The results showed the Interplak is significantly better in toothbrusing efficiency. Similar result was found in Youngblood et al. in 1985, when they examine the effectiveness of Interplak instrument compared to manual toothbrushing using modified Bass technique in removing subgingival and interproximal plaque.

Dental floss is the most widely recommended mehtod for removing proximal plaque. In flossing, the floss is wrapped around each proximal surface and is activated with repeated up and down stroke. Floss should pass gently through the contact area. Do not snap the floss pass the contact area as it may injure the interdental papilla. In fact, proximal grooves are created by zealous snapping of floss through contact areas. Floss is available in many types: unwaxed, waxed, tape floss, ePTFE floss, and Superfloss. Waxed floss contained wax to facilitate passing the floss the floss through the contact and alleviate fraying. Tape floss contain criss-cross fiber and eliminate fraying. PTFE floss (Glide floss) is the teflon floss which allow passing through very tight contact easily without fraying. Superfloss is the web-like material which improved proximal cleaning efficiency.

Lambert et al. in 1982 compare the waxed and unwaxed floss to determine the efficacy to remove plaque and their effect on gingival health during a home oral program. The results showed there was no statistical difference between the types of floss in regards to their ability to remove plaque or prevent gingivitis. Similarly, Wunderlich et al. in 1982 reported there is no difference between wax and unwaxed floss in maintaining gingival health.

Superfloss, a product of which the part that pass between the interproximal space is made of a web like material, offered better cleaning efficiency in the proximal space, as found the Wong and Wade study in 1985, which they compared the effectiveness of Super floss and waxed dental floss as proximal surface cleansing agent in 34 subject. Graves et al. in 1989 evaluated in a 2 week clinical trial the efficacy of unwaxed dental floss, dental tape, waxed floss, and tooth brushing alone in reduction of interproximal bleeding. The result showed that the dental tape and dental floss were equally effective in reducing interproximal bleeding and doubly effective as toothbrushing alone.

Another very important interproximal space cleaning device is the interdental brush (proxy brush). Interdental brush are conical shape brushes made of bristles mounted on a handle, single tufted brushes, or small conical brushes. They are suitable for cleaning large, irregular, or concave tooth surfaces adjacent to wide interdental spaces. They are inserted interproximally and are activated with short back and forth strokes in between the teeth. Waerhaug in 1976 evaluated the effec tof interdental brushes on sixty seven teeth which scheduled for extraction. Teeth were cleaned prior to extraction and then stained and examined with the stereoscope after extraction. The results indicated that plaque can be removed from 2 to 2.5mm subgingivally using the interdental brush.
Other oral hygiene device can be included are toothpick, disclosing agents, and the oral irrigation device. Studies have been conducted to compare the efficacy of tooth pick, dental floss, and multi-tufted brush. Dental floss removed more plaque at lingual interproximal surface than toothpicks. Toothpicks combined with multi-tufted brush used on oral surfaces were as effective in removing interproximal plaque as dental floss. The use of floss or tooth pick combined with single tufted brush may reduce the amount of plaque adhering to the proximal surfaces by an average of 50%. Disclosing agents are staining agents which stain food debris, plaque, and thus assist the patient to visually inspect his or her oral hygiene effort. Oral irrigation device include the use of water picks. The high pressure, pulsating stream of water through a nozzle is directed to the tooth surface and subgingivally, washing away debris and plaque containing bacteria. They are helpful surrounding orhtodontic appliance, and when used as an adjucntive treatment in shallow pocket depth, they can retard the accumulation of plaque and calculus, and thus reducing gingival inflammation and pocket depth. Eakle et al. in 1986 showed that the oral irrigator deliver an aqueous solution into the periodontal pocket and will penetrate an average to approximately half the depth of the periodontal pockets. Penetration of 90 degree angle stream of water is about 70% for pocket less than 3mm, 44% for moderate pocket (4 to 7 mm) and 68% for deep pocket ( greater than 7mm). For 45 degree angle, the result is 54%, 45%, and 58% respectively. Ciancio in 1989 evaluate the efficacy of an antimicrobial rinse delivered by an oral irrigation device twice daily. The results showed that irrigation with or without an antimicrobial agent was effective in reducing the plaque, suggesting that oral irrigation may be beneficial on oral health and the use of the chemotherapeutic agent will lead to greater reduction in plaque and gingival bleeding and to moderate decreases in total bacteria counts detected by phase contrast microscopy.

Regardless the means to achieve the goal, mechanical plaque control is the key to the success of periodontal therapy and achieving dental health. Good mechanical plaque control program should be included in the first phase of therapy and reinforced through the entire therapy. The clinician must evaluated patient plaque control by means of gingival and plaque indices to motivate the patient toward the common goal, the optimal periodontal health. Common devices to be recommended to the patient are soft bristle tooth brush, floss, interproximal brushes, and optional intraoral irrigation devices. With good oralphysiotherapy, gingivitis can be prevented and periodontal disease with bacterial as the main etiological factor can be erradicated.

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References

1. Loe, H. Theilade, E., Jensen, SB. Experimental Gingivitis in Man. Journal of Periodontology, 36: 177, 1965.

2. Sanders, WE. Robinson, HBG. The effect of toothbrushing on deposition of calculus. Journal of Periodontology 33: 386, 1962.

3. O’Leary, Shafer W., Swenson H, Nesler D. Possible penetration of crevicular tissue from oral hygiene procedure. Use of the toothbrush. J. Periodontology, 41:163, 1970 A.

4. Caranza, Newman. Textbook of clincal periodontology. Eighth edition. WB Saunders, 1996.

5. Grant, Stern, Listgarten. Textbook of Periodontics. Sixth Edition. The C.V. Mosby Company, 1988.

6. Genco, R., Goldman, H., Cohen, W. Contemporary Periodontics. The C.V. Mosby Company , 1990.

7. Killoy, W. Love J., Fedi, P. Tira, D. The effectiveness of a counterrotary action powered toothbrush and conventional toothbrush on plaque removal and gingival bleeding. Journal of Periodontology, 60: 473, 1989.

8. Lamberts, D. Wunderlich, R. Caffesse, R. The effect of waxed and unwaxed dental floss on gingival health. Part 1. Plaque removal and gingival response. Journal of Periodontology, 53: 393, 1982.

9. Graves, R. Disney J. Stamm J. Comparative effectiveness of flossing and brushing in reducing interproximal bleeding. Journal of periodontology, 60: 243, 1989.

10. Ciancio, Mahter, Zambon, Reynolds, H. Effect of chemotherapeutic agent delivered by an oral irrigation device on plaque, gingivitis, and subgingival microflora. Journal of Periodontology, 60: 310, 1989.

11. Eakle, W. Ford, C., Boyd, R. Depth of penetration in periodontal pockets with oral irrigation. Journal of clinical Periodontology, 13: 39, 1986.