Rat study finds early secondhand smoke exposure can alter tooth enamel mineralization
Exposure to secondhand cigarette smoke during the first days of life can cause changes in tooth enamel mineralization without causing visible changes to the teeth. This was demonstrated in an animal model study conducted by researchers at the Ribeirão Preto School of Dentistry at the University of São Paulo (FORP-USP) in Brazil. The results were published in May in the scientific journal…
A recent study using rats has found that early exposure to secondhand cigarette smoke can alter tooth enamel mineralization, even without visible changes to the teeth. Conducted by researchers at the Ribeirão Preto School of Dentistry at the University of São Paulo in Brazil, the study was part of a broader investigation into the impact of early-life adversities on development. Supported by FAPESP, the research took place during Juliana de Lima Gonçalves' doctoral studies.
The study focused on the impact of secondhand smoke on tooth enamel, which serves as a biological record of early exposures. Enamel, a hard structure that forms during pregnancy and continues to form in children, was chosen as a biomarker because it doesn't remodel after formation, unlike bone. Researchers divided baby rats into two groups: one exposed to cigarette smoke for five minutes twice a day from the second to the 28th day of life, and a control group not exposed.
The smoke-exposed animals gained less weight than the control group, consistent with previous research.
Despite no visible differences in teeth, microscopic and chemical analyses revealed increased space between enamel prisms and reduced levels of phosphorus in the enamel of smoke-exposed animals. Phosphorus is a key component of hydroxyapatite, giving tooth enamel its hardness. The study also found increased carbon content in the enamel of smoke-exposed animals, suggesting a higher presence of organic material, which is unusual for enamel. However, the initial hardness of the enamel remained unchanged.
The researchers hypothesize that the young age of the animals, who were weaned at 21 days, may explain the lack of reduction in initial hardness, as they hadn't used their teeth much. Future research will explore how these enamel changes may impact tooth strength with use over time. The study also aims to determine if more intense exposure to cigarette smoke can produce more pronounced enamel changes, potentially resembling human cases.
Scientists are also investigating the stage of enamel formation most susceptible to cigarette smoke's effects.
Written by urgent.news from Medical Xpress's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
