What the Experts are saying

Study to Evaluate the Effectiveness of an Iontophoretic Toothbrush in the Removal of Dental Plaque

R.L.Van Swol, D.E.Van Scotter, A.R.Dentino, J.J.Pucher

A clinical study at Marquette University School of Dentistry has demonstrated the effectiveness of a manual Hukuba hyG IONIC toothbrush in unsupervised brushing for six months. The double-blind study had 64 adult subjects ranging in age from 18 to 67 years. They were divided into two groups: Group 1, the test group, had 30 subjects using the hyG Ionic Toothbrush with an active battery. The control group, Group 2, had 34 subjects using the hyG IONIC toothbrush without an active battery.

The mechanism for the ionic action is due to a change in the polarity of the teeth. The tooth is normally negatively charged and the plaque is positively charged. Opposite charges attract and bond to each other. The plaque, therefore, is attached to the tooth surface by "ionic bonding".

hyG IONIC toothbrush schematic

The hyG toothbrush has a three (3) volt lithium battery located under the metal band on the handle. The battery is similar to a watch battery and just as safe. The toothbrush bristles are negatively charged through the metal rod with the brush head. When holding the metal band on the toothbrush handle with moistened fingers, the positively charged ions are transferred to the teeth.

The tooth polarity changes from negative to positive. The positively charged tooth ions repel the positively charged plaque ions. The positively charged plaque ions are then attracted to the negatively charged bristles of the hyG toothbrush for removal from the oral cavity.

BEFORE: Opposite polarity makes plaque (+) adhere to teeth (-).

AFTER: hyG temporarily reverses polarity of tooth surface from (-) to (+), repelling plaque toward negatively polarized hyG toothbrush head.

This important ionic exchange along with the normal mechanical action of the bristles on the tooth surface enhances plaque removal. Moist finger contact with the metal band on the hyG toothbrush handle is essential to maximize ionic transfer of plaque molecules between the teeth and the toothbrush bristles.


Plaque scores were determined at baseline, three and six months using the Turesky-Gilmore-Glickman Index. Likewise, gingival indices were determined using the Loe Silness Gingival Inflammation Index.

Group 1 (test) showed a 36.17% reduction in plaque from baseline to month six, compared to only 18.56% for the control group. Improvement in gingival health was 51.87% for the test group and 30.18% for the control group. The average changes in both plaque and gingival indices were statistically significant for the test group using the hyG IONIC toothbrush with an active battery.

The toothbrushes were identical except for the presence of the active battery. The ionic action from the three (3) volt lithium battery produced the significant plaque and gingival changes observed.

The Hukuba hyG IONIC toothbrush is a safe and effective oral cleansing device when used unsupervised on a regular basis in the removal of human dental plaque.



  1. Plaque removal. Estimates according to O'Leary's PCR (p<0.01) and PHP (p<0.05), the efficacies of the lithium battery toothbrush and the control toothbrush differed significantly.<0.01) and PHP (p<0.05), the efficacies of the lithium battery toothbrush and the control toothbrush differed significantly.

  2. Improvements in gingivitis. In terms of the PMA index (p<0.05), the lithium battery toothbrush produced better results than the control toothbrush.<0.05), the lithium battery toothbrush produced better results than the control toothbrush.

  3. Changes in bacterial levels. No changes in oral microorganism levels were observed after the experimental period, no matter which kind of toothbrush was used.

  4. Plaque accumulation compared in terms of caries risk group. In the Low risk group, no significant differences were observed between the toothbrushes before and after the experimental period. In the High risk groups, however, the lithium battery toothbrush removed bacterial plaque more effectively.

1993 study, Maki Y. ET AL., Tokyo Dental College


...Finding suggest that improvements in gingivitis might be expected through charging gingivital tissue electronically in addition to mechanical plaque removal by toothbrush itself.

1993 Kasai S. ET AL., Kyushu Dental College


Results and conclusions:

Both plaque grading methods revealed a percent difference in favor of the hyG treatment. The six selected tooth surfaces employed in the PHP index support the conclusion that the hyG brush is superior in plaque removal to an ADA accepted brush (Butler Gum #440).

1991, Bieswanger, B., DDS, Oral Health Research Institute
Indiana University School of Dentisty


The electronic toothbrush (hyG) was much more effective in plaque removal than the ordinary toothbrush in all the subjects...The effectiveness of the electronic toothbrush can be expected even if there are differences in brushing techniques. The most valuable results in this study were seen at the cervical region...the hardest place to clean.

1990 Study, Tokyo Dental College


...All thirteen subjects achieved higher plaque removal with the iontophoretic toothbrush (hyG) than with the ordinary toothbrush with a high statistical significance of P<0.001. The "hard" bristles of the iontophoretic toothbrush (0.28 MM nylon filament) achieved higher plaque removal than the medium hard (0.23 MM) bristles.

< 0.001. The "hard" bristles of the iontophoretic toothbrush (0.28 MM nylon filament) achieved higher plaque removal than the madium hard (0.23 MM) bristles.

1986, Otani, H,. ET AL., Asahi University


The object of the investigation was to test the value of the 3M Brand Electro-Ionizing Toothbrush in the treatment of dentinal hypersensitivity. Eighty-eight volunteers were divided into three groups, each using different methods: (I) stannous fluoride dentifrice and 3M brush without a battery; (II) stannous fluoride dentifrice and 3M brush with a 1 1/2 volt battery; (III) strontium chloride dentifrice and 3M brush without a battery. The volunteers brushed their teeth for 3 minutes twice a day for 12 weeks using one of the three test agents. The subjects were tested at weeks 0, 2, 4, 8, and 12 by means of a cold water spray quantitated by a temperature probe. All three groups experienced improvement and by week 12 groups II and III displayed much less sensitivity than did group I. At the end of 12 weeks the subjects were questioned as to benefit of treatment. The questionaire revealed that stannous with the ionizing brush provided significantly greater relief than did the stannous fluoride alone.

J. Periodontal June 1982, P.353-9 issn 0022-3492
Johnson R.H.;Zulgar-Nain BJ; Koval JJ;
J. Peridontal ISSN 0022-3492


The following results were obtained:

  1. The clinical effect (reduced hypersensitivity) of the iontophoretic was significantly different from the placebo group after two weeks (P<0.01) and it was a highly significant difference (P<0.001) after six weeks. In the active group the reduction in sensitivity after six weeks was shown to be 60.6% and in the placebo group 25.4%.<0.01) and it was a highly significant difference (P<0.001) after six weeks. In the active group the reduction in sensitivity after six weeks was shown to be 60.6% and in the placebo group 25.4%.


  2. 50.1% of the initially sensitive teeth had lost all sensitivity after six weeks.

  3. No side effects of this iontophoretic toothbrush were observed.

    On the basis of the above facts, it is concluded that an iontophoretic toothbrush used with a fluoride dentifrice is highly effective in cervical hypersensitivity. Accordingly, the use of an iontophoretic toothbrush is a simple and available method for home dental care.

    ... iontophoresis is indeed highly effective.

    ... This technique has no equal in relieving dental hypersensitivity.

1979, Ota, N., et al.,Matsumoto Dental College


Collins found an 87.5% decrease in hypersensitivity in his active group and a 22.8% decrease in the control group.

Producing iontophoresis of fluorides in daily oral hygiene by the use of an electronically charged toothbrush could open the way to even greater benefits from the use of fluorides in dentistry. Since it has been shown previously that topical fluoride has a certain, although limited, effectiveness in alleviating hypersensitivity, the increase of effectiveness under the influence of an electronically charged toothbrush is suggestive evidence that this device increases the deposition of fluoride on, or within, the tooth.

From available evidence it seems unlikely that fluoride would reach the pulp in sufficient quantities to have any adverse effect.

. . . pathological studies of tooth pulps after iontophoresis of fluoride have been described in two recent reports.

. . . all pulps were regenerated completely histologically.

. . . histological examinations revealed no evidence of any permanent pulp damage.

. . . enamel pore wall is negatively charged . . . facilitating the penetration of positively charged ions (cations) and resisting the penetration of negatively charged ions (anions). Thus, the penetration of fluoride, which is the most negative ion normally is resisted by the enamel.

The fact that similar charges repel and opposites attract . . . if the negative charge of the enamel is temporarily reversed to positive the amount and depth of penetration of negative ions (fluorine) is facilitated.

. . . a majority of subjects in the active group reported a new feeling of cleanliness in their mouth, similar to having their teeth cleaned by a dental hygienist.

. . . various other oral processes may be affected, such as the deposit of calculus.

. . . use of an iontophoretic toothbrush resulted in the removal of protein matrix and free calcium adhering around the teeth, and the removal of putrefied matter coming from inflammation.

. . . no undesirable side effects were noted after two years of continued routine use.

1964, Jensen, A. L., University of California, College of Dentistry


The teeth can be charged with a positive electrical potential by means of a battery while fluoride is being applied. Since fluorine is the most negative of all ions, iontophoresis may be employed as a practical method to increase penetration or deposition of fluoride in the dental enamel and dentine.

. . . an (electrical) potential low enough to be considered safe for continued use.

. . . electrical potential of the magnitude delivered by the iontophoretic toothbrush appears to be safe for daily use. Lefkowitz reported using a potential five hundred times greater . . . than supplied by the brush without damage to the pulp. There was no apparent damage to the soft or hard tissue of the oral cavity.

Home care . . an affective treatment by simply brushing teeth with a fluoride dentifrice and an iontophoretic toothbrush.

. . . an exceedingly potent therapeutic means of relieving hypersensitivity.

1962, Collins E.M., Loma Linda University, College of Dentistry