Related Experiment Video
Updated: Feb 3, 2026

Oral Biofilm Sampling for Microbiome Analysis in Healthy Children
Published on: December 31, 2017
Bacterial viability in oral biofilm after tooth brushing with amine fluoride or sodium fluoride
E A Naumova1, L Weber1, V Pankratz1
1Dept. of Biological and Material Sciences in Dentistry, School of Dentistry, Faculty of Health, Witten/Herdecke University, Witten, Germany.
Objective:
The aim of this study was to investigate the effects of sodium fluoride (NaF) and amine fluoride (AmF) on bacterial viability in the oral cavity.
Material And Methods:
Healthy subjects brushed their teeth with either fluoride free toothpaste, NaF- or AmF-containing toothpaste. Biofilm smears from different locations were collected before and immediately and 30 and 120 min after tooth brushing. The smears were stained with live/dead bacterial staining, and the number of the respective bacteria was counted. The data were statistically analyzed by comparing the numbers of bacteria before and after the application of no fluoride, NaF and AmF.
Results:
The highest numbers of bacteria were found in the tongue biofilm, followed by the palatal and cheek biofilm. The lowest numbers were found in the mouth floor biofilm. After the application of AmF, no changes in the numbers of bacteria were found in the biofilms, except for the cheek, where they were reduced. After the application of NaF, the number of bacteria decreased significantly in all biofilms. After 120 min, bacterial regrowth was complete.
Conclusions:
AmF has only little effect on the bacterial viability of oral biofilms. NaF application reduces the number of living bacteria in the oral biofilms. This effect lasts not longer than 120 min.
Related Concept Videos
Bacterial Signaling
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...
Amines to Amides: Acylation of Amines
Next, the second equivalent of amine serves as a Brønsted base and deprotonates the quaternary...
Preparation of Amines: Alkylation of Ammonia and Amines
Each alkylation step makes the nitrogen center more nucleophilic, which triggers successive alkylations until a quaternary ammonium salt is formed. Considering...
Biofilms
Preparation of Amines: Reductive Amination of Aldehydes and Ketones

