The effects of load and toothpaste on powered toothbrush vibrations
Related Experiment Video
Updated: Jul 18, 2026

Impact of Common Fruit Juices and Toothbrushing on the Discoloration of Primary Teeth
Published on: March 27, 2026
Simon C Lea1, Amina Khan, Hussein S Patanwala
1School of Dentistry, The University of Birmingham, St. Chad's Queensway, Birmingham B4 6NN, United Kingdom. s.lea@bham.ac.uk
Objectives:
The primary cleaning action of powered toothbrushes is the motion of the bristles in contact with the tooth surfaces. The aim of this study was to use scanning laser vibrometry to determine the effects of load and toothpaste on the bristle vibration characteristics of four powered toothbrushes (Oral-B Sonic Complete; Oral-B Professional Care 8000 Series; Sonicare Elite and Ultrasonex).
Methods:
Toothbrushes were initially scanned, with the laser vibrometer, under unloaded conditions to provide baseline readings. Toothbrushes were then assessed under loaded conditions (1.00 N and 2.00 N), with and without toothpaste, to observe the effect on bristle motion.
Results:
Application of 1.00 N load significantly reduced the displacement amplitudes of all powered toothbrushes (p<0.003) except for the Sonicare (p>0.497). With toothpaste, 1.00 N load caused a significant decrease in vibration displacement amplitude for all brushes (p<0.0001). The application of 2.00 N, with and without toothpaste, significantly reduced all toothbrushes vibration displacement amplitude (p<0.0001). Under all investigation conditions, the Oral-B 8000 had the largest vibration displacement amplitude of the toothbrushes tested.
Conclusions:
Load and toothpaste significantly affected the performance of powered toothbrushes. Understanding why these factors affect certain toothbrush designs more than others may lead to toothbrushes being designed with greater clinical efficacy.
Related Concept Videos
Muscle Stimulation Frequency
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Tooth Anatomy
The Crown, Neck, and Root
The visible part of the tooth is referred to as the crown. It's covered by enamel, the hardest substance in the human body. The crown is uniquely shaped for each type of tooth, allowing for different functions such as cutting, tearing, or grinding food.
Vibrating Concrete
Forced Oscillations
Power Expended by a Constant Force
Impact Loading
In cases of elastic deformation,...

