By Ayah Al-Ani
It has been shown that diabetes mellitus (DM) negatively impacts the dental and periodontal tissues of the oral cavity, but different mechanisms were proposed to explain the adverse effects on the tooth hard tissues. To more specifically address this topic, researchers at Rutgers University aimed to explore the impact of type 1 diabetes mellitus (T1DM) on the microhardness of tooth enamel and dentine in mice. Diabetes mellitus can be defined as a chronic metabolic disease that is the result of compromised insulin secretion and/or impaired insulin action in the tissues of the body. This impaired ability to secrete insulin has been shown to negatively impact salivary composition and flow rate, which in turn cause negative effects on the mechanical and tensile properties of the enamel and dentine.
Saghiri et al. 2022, utilized the Vickers microhardness test to determine the second molars’ enamel and root dentine deformation in normal and diabetic mice at different time points. Seventy mice were used in total, thirty-five of which were rendered diabetic by the administration of streptozotocin, which has been widely used in other studies to induce hyperglycemia in mice. Both groups’ teeth were compared over a period of 28 days.
The results indicated that the microhardness value of enamel was significantly reduced (P < 0.05) in the diabetic teeth specimen at 12 weeks. When comparing the microhardness value of dentine, the value significantly decreased at the 28-week mark (P < 0.05). These results indicated that T1DM negatively affects the enamel and dentine microhardness, with the enamel being much more negatively and rapidly impacted than the dentin in the diabetic group. The researchers also found that aging decreased the microhardness of enamel and increased the microhardness of dentine in non-diabetic mice.
Saghiri and collaborators reasoned that the negative impact that DM had on tooth enamel and dentine was most likely attributed to its adverse effect on the metabolic functions of the ameloblasts (cells that create enamel matrix) and odontoblasts (cells that create dentine). Another explanation was that the enamel structure found in diabetic rodents suffered from a significant reduction in the amount of calcium and phosphate. Saghiri et al. also pointed to a third possible explanation, that the DM affected the orientation and arrangement of effector molecules such as enamel proteins. It has also been shown that hyperglycemia can hinder the maturation and mineralization of the collagen matrix during dentine formation. This decrease in mineralization could explain the decrease of the enamel and dentine microhardness value.
This study aimed to determine the impact of T1DM on the microhardness of tooth enamel and dentine in mice. The results concluded that T1DM negatively impacted both the enamel and dentine, but had a greater impact on the enamel in the diabetic group. Furthermore, this was most likely attributed to the negative impact of T1DM on the ameloblast and odontoblast cells’ function.
There is, however a caveat on how to transpose these data to humans. It is well known, that rodents are monophyodonts, meaning have one set of teeth and they generate tooth structure (dentin and enamel) throughout life. Humans are diphyodonts and once a tooth erupts, the human’s ability to regenerate enamel is lost. Dentin (tertiary) is continuously generated throughout life. Therefore, at best, the diabetic microhardness study in mice can be interpolated only to developing (unerupted) human enamel.
This study provided further guidance to comprehend the impact of diabetes on dental health and hoped to guide the development of mitigatory treatments. It also supported previous studies which determined that people suffering from either type of diabetes had much higher incidences of oral health issues compared to the non-diabetics, primarily due to slower healing of soft tissue, higher rate of oral infections and loss of periodontal support structures. Since the diabetic population continues to grow rapidly, there is a higher chance of encountering them in dental practice.
For the aspiring dental professional, this research further reinforces the connections between oral and systemic health. Furthermore, due to the negative impact that DM has on the tooth structure, diabetic patients are often more prone to oral infections, tooth loss, and potentially higher rates of dental caries. Knowing this, more preventative measures and resources should be directed towards this population. For instance, this could translate to conducting check-ups at shorter time intervals to more closely monitor the patients’ oral health and decrease the risk of future caries development.
Reference:
Saghiri, M. A., Sheibani, N., Kawai, T., Nath, D., Dadvand, S., Amini, S. B., Vakhnovetsky, J., & Morgano, S. M. (2022). Diabetes negatively affects tooth enamel and dentine microhardness: An in-vivo study. Archives of oral biology, 139, 105434. https://doi.org/10.1016/j.archoralbio.2022.105434.
Comments