Tooth Brushing Learning Methods: Differential or Conventional? - A Randomized Controlled Clinical Trial
Related Experiment Video
Updated: Jul 1, 2025

Precision of In Vivo Quantitative Tooth Wear Measurement Using Intra-Oral Scans
Published on: July 12, 2022
Loay Leghrouz1, Manasi R Khole1, Christian H Splieth1
1Department of Preventive and Pediatric Dentistry, University of Greifswald, Greifswald, Germany.
Introduction:
Proper tooth brushing is a complicated process for children. Therefore, the aim of this study was to investigate the effect of differential learning to improve tooth brushing in children.
Methods:
In this prospective, controlled, single-blinded, randomized clinical trial, 58 children between 3 and 8 years of age (mean: 5.7 ± 1.5 years; 29 female) were randomly assigned to test or control group through the child's self-drawing of an unlabeled envelope from a box. All children received oral hygiene instructions and information in these sealed envelopes and were asked to follow the corresponding instructions at home for 28 days. Children in the test group received instructions with exercises using the differential learning method, whereas the children in the control group received the usual tooth brushing instructions.
Results:
At baseline and planned follow-ups after 4 and 12 weeks, plaque and gingival indices (QHI, PBI) were recorded in both groups by 2 calibrated and blinded investigators. At baseline, there were no significant differences between the test and control groups regarding plaque and gingival indices (QHI: 4.1 ± 0.5 vs. 4.1 ± 0.4; p = 0.7; PBI: 0.6 ± 0.3 vs. 0.6 ± 0.3; p = 0.7). At the 1st and 2nd follow-up, both groups showed improved oral health indices, but there was an overall better improvement in the test group. While the difference in gingival indices was statistically significant in the 1st recall (PBI/test: 0.1 ± 0.2 vs. control: 0.3 ± 0.2; p < 0.001), the difference in plaque indices was not (QHI/test: 2.1 ± 0.9; control: 2.6 ± 0.9; p = 0.07). At the 2nd recall (mean week = 19.5 weeks), the test group showed statistically significant and clinically relevant better oral health indices than the control group (2nd recall, QHI/test: 2.1 ± 0.9 vs. control: 3.2 ± 1; p < 0.001; PBI/test: 0.1 ± 0.2 vs. control: 0.5 ± 0.2; p < 0.001).
Conclusion:
In conclusion, differential learning leads to oral hygiene improvement in children with high caries risk and initially poor oral hygiene, which was superior to the conventional learning method through repetition in the medium term.
Related Concept Videos
Associative Learning
Classical conditioning, also known...
Blinding
Crossover Experiments
Crossover designs are performed even with smaller sample sizes since the samples can act as their controls. These are better than simple randomized trials since patients are exposed to all the treatments.
Randomized Experiments
Simple randomization
Simple...
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...
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...

