Related Experiment Video
Updated: Oct 4, 2026

Impact of Common Fruit Juices and Toothbrushing on the Discoloration of Primary Teeth
Published on: March 27, 2026
Safety of three toothbrushes
1The Procter & Gamble Company, Cincinnati, Ohio, USA. he.t@pg.com
Purpose:
To assess the oral soft tissue safety and tolerability of two electric toothbrushes, the Crest Spin Brush and Colgate ActiBrush, and one manual toothbrush, the Oral B 40.
Materials And Methods:
A total of 104 subjects were enrolled in this single center, randomized, examiner-blind parallel study over a 4-wk test period. Subjects were randomized to treatment and were instructed to brush in their normal manner, twice per day for 60 s. A detailed oral soft tissue examination and interview were conducted by a trained clinician at baseline, 3 days and 4 wks to assess clinical signs and symptoms associated with use of the toothbrushes.
Results:
Over the 4-wk period, a total of 19 subjects (18% of the study population) were observed for signs/symptoms. The adverse events were distributed across test groups with 12 subjects in the Oral B 40 group, 4 subjects in the Crest Spin Brush group, and 3 subjects in the Colgate ActiBrush group experiencing at least one adverse event. All adverse events were mild in severity indicating the general safety of all three toothbrushes. The most frequently encountered event was localized gingivitis. The Oral B 40 test group was observed with more adverse events when compared to the Crest Spin Brush and Colgate ActiBrush at 4 wks but not at 3 days. The proportion of subjects experiencing an adverse event in the Crest Spin Brush test group was similar to that of Colgate ActiBrush group. All three toothbrushes were generally well tolerated by subjects enrolled in the study with the Crest Spin Brush and Colgate ActiBrush being the best tolerated.
Clinical Significance:
The results of this study indicated that abnormal oral soft tissue findings were distributed among the treatment groups, indicating that daily use of an electric toothbrush is at least as safe as a manual toothbrush.
Related Concept Videos
Teeth
In the bud stage, the tooth germ (an aggregation of cells) starts to form in the developing jawbone. During the cap stage, the tooth germ differentiates into enamel organ, dental papilla, and dental sac, which will later develop into the tooth's enamel, dentin and...
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.
Handwashing III: During the Procedure and Post-Procedure Steps

