The cleansing efficacy of brushing with the
amabrush® versus manual toothbrushing was evaluated in a randomized-controlled, examiner-blinded, two-period crossover study. Each subject was asked to attend four appointments. At day one, the probands were informed about the study procedure; they signed an informed consent, and inclusion and exclusion criteria were proofed. After plaque disclosing (
2Tone, Young, Earth City, Mo, USA), professional tooth cleaning was accomplished with an air-polishing device (
Airflow® prophylaxis master and
Airflow® Plus powder; both EMS, Nyon, CH), and, if appropriate, with sonic scalers and rubber cups with polishing paste (
Cleanic®, Kerr, Bioggo, CH). Each proband was instructed to refrain from oral hygiene, including toothbrushing, the use of dental floss or other interdental cleaning devices, and the use of mouth rinses or chewing gum for 3 days. According to a computer-generated randomization (
Microsoft® Office Excel), probands were allocated either to group 1, designated to start with using the
amabrush®, or group 2, determined to start with manual toothbrushing. After 3 days of undisturbed biofilm accumulation, plaque was disclosed and scored by two blinded investigators (DS and WS) using the Rustogi Modified Navy Plaque Index (RMPN) [
8] before (baseline) and after brushing with the assigned device. Probands of group 1 were assisted with using the
amabrush® according to the manufacturer’s instructions. Only one size (model “Amabrush Version 1.0”) was available at the time the study was conducted. The mouthpiece was wetted and attached to the handpiece, which was loaded with the pod containing the “fresh” toothpaste. The toothpaste button was pressed to inject the toothpaste. After insertion of the mouthpiece and adjustment between the dental arches so as to ensure maximum fit, the start button was pressed. After 10 s, the brushing automatically stopped. The mouthpiece was removed and the probands were instructed to rinse with water. The RMNPI was assessed and teeth were air-polished. Probands of the group 2 were told to brush their teeth with a manual toothbrush (
Oral B Indicator Medium 35®
, Procter & Gamble UK, Weybridge, Surrey, UK) that had been dipped once into the same (liquid) “fresh” toothpaste, which had been poured into a cup. Toothbrushing was performed without instruction and in the absence of a mirror to ensure that the probands had no visual control of the disclosed plaque. The respective brushing method was recorded and the brushing time was stopped and chosen freely up to a maximum of 4 min. After rinsing with water, the RMNPI was assessed and air-polishing was performed. After a wash out phase of 11 days when the probands were practicing their usual oral hygiene procedures, they presented for the third visit (day 15). Again, plaque was disclosed and teeth were cleaned by air-polishing. After abolishing oral hygiene for 3 days, the fourth visit (day 18) unfolded in analogy to the second visit, with group 1 using the manual brush and group 2 using the auto-cleaning device.
Alginate impressions of both jaws were taken to obtain stone plaster casts for the evaluation of the size and shape of the dental arches and the investigation of the auto-cleaning device’s fit.