Fluoride alters connexin expression in rat incisor pulp

Area of Science:

• Dental tissue development and mineralization
• Toxicology of fluoride compounds
• Cellular communication via connexins

Background:

• Connexins (Cxs) are crucial for regulating dental tissue growth and differentiation.
• Fluoride exposure can impact dental development, but its precise effects on connexin expression and pulp activity are not fully understood.

Purpose of the Study:

• To investigate the effects of chronic sodium fluoride (NaF) exposure on connexin expression and alkaline phosphatase (ALP) activity in dental pulp.
• To assess the impact of NaF on the morphometric parameters of adult rat mandible and incisors.

Main Methods:

• Three groups of male Wistar rats were exposed to varying concentrations of NaF (0, 10, and 50 mg/L) in drinking water for eight weeks.
• Connexin 32, 43, and 45 gene expression was analyzed using semi-quantitative RT-PCR.
• Alkaline phosphatase (ALP) activity and morphometric parameters of mandible and incisors were measured.

Main Results:

• NaF exposure led to a dose-dependent increase in Cx43 gene expression.
• ALP activity was significantly higher in rats exposed to higher NaF concentrations.
• Incisor diameter decreased in the highest NaF group, while mandibular growth parameters were unaffected.

Conclusions:

• Fluorotic alterations in rat incisors are linked to elevated Cx43 expression and ALP activity.
• Changes in connexin expression patterns in pulp tissue suggest a role in modulating dentin mineralization.
• NaF exposure impacts incisor morphology and pulp biochemistry, with potential implications for dentin formation.