Why do some people remain cavity-free even with poor hygiene? The concept of being born with either "strong teeth" or "weak teeth" has been around in folklore for hundreds of years. Dentists have normally disregarded this, citing the extensive evidence of how diet and hygiene affect oral health. While they are quite correct in this association, what about the people with poor oral hygiene who always seem on the brink of developing cavities each dental visit, but never quite develop a full lesion?
Recently, researchers have implicated a genetically-determined contributor to enamel health during development which may explain this inconsistency. Called amelogenin, deficiency in this protein produces the disease amelogenesis imperfecta. This disease is already known to the medical community, but variations in the amount of amelogenin have not been investigated beyond simple deficiency until now.
X-chromosome-linked amelogenin is the most heritable form of this protein, and was selected as the target gene to modulate in the study. Researchers bred successive generations of transgenic mice containing either a deficiency in amelogenin, or a transgene that over-expresses amelogenin, which would later be compared against wild-type mice (mice with no gene modification). A population of young adult mice (six weeks old) totaling 60 individuals was selected for analysis along with 108 adult mice (five months).
The enamel surface microhardness was measured using the Knoop hardness test, in which a diamond point was pressed into the enamel surface with a given force, for a predetermined length of time. The indentation that results was then measured, and computed along with the force and time to give the result. After an initial measurement, artificial caries lesions were created.
These lesions were prepared by immersing the teeth in a de-mineralizing solution for 16 hours. According to the study, "this method produces a subsurface enamel demineralization without surface erosion." After treatment with the demineralizer was completed, surface microhardness was measured again using the same test. These two hardness values for each sample were compared, and the differences analyzed by the ANOVA statistical process.
Next, each tooth was subjected to an antibody probe to assess the level of x-linked amelogenin expression using a Western blot assay. The levels of amelogenin were compared against the respective hardness and resilience values of the enamel samples.
The results of the study indicate that amelogenin expression is directly and positively correlated with stronger enamel that is more resistant to carious lesions. Given this understanding, future prophylactic measures against cavities may include gene therapy or amelogenin-promoting supplements for expectant mothers or infants who test as low-amelogenin producers. In fact, depending on the safety of the process, amelogenin may become as common as fluoride as a preventative measure against cavities for all patients. After all, isn't it better to start strong than play catch-up later?
Source:
Vieira, A. R., Gibson, C. W., Deeley, K., Xue, H., & Li, Y. (2015). Weaker Dental Enamel Explains Dental Decay. PLOS ONE PLoS ONE, 10(4). Retrieved February 9, 2016.
The information contained in this, or any case study post in Incisor should never be considered a proper replacement for necessary training and/or education regarding adult oral conscious sedation. Regulations regarding sedation vary by state. This is an educational and informational piece. DOCS Education accepts no liability whatsoever for any damages resulting from any direct or indirect recipient's use of or failure to use any of the information contained herein. DOCS Education would be happy to answer any questions or concerns mailed to us at 106 Lenora Street, Seattle, WA 98121. Please print a copy of this posting and include it with your question or request.
