<p>This study aimed to evaluate the effect of different periods of exposure to the intracanal medication Bio-C Temp (Angelus) on the chemical composition and fracture resistance of root dentin. Sixty bovine roots with similar anatomical characteristics were selected and evenly distributed into five groups (<i>n</i> = 12) according to the time of exposure to the intracanal medication Bio-C Temp (Angelus): control (without medication), 7&#xa0;days, 14&#xa0;days, 30&#xa0;days, and 90&#xa0;days. After each experimental period, the medication was removed, and the roots were embedded in cylindrical acrylic molds for fracture resistance testing and fracture pattern analysis. In addition, dentin blocks were obtained from unused root segments, subjected to the same experimental protocols (<i>n</i> = 6), and analyzed for chemical composition and topography using SEM/EDS. One-way ANOVA, Tukey's post hoc, and Fisher's exact tests were performed (<i>α</i> = 5%). The control group exhibited higher fracture resistance than the 90-day group (<i>p</i> &lt; 0.05), while no differences were observed among the other groups or in the distribution of fracture patterns (<i>p</i> &gt; 0.05). EDS analysis revealed alterations in the elemental composition of dentin in the control group compared with all other groups, with a more pronounced decrease in inorganic components observed in the 90-day group (<i>p</i> &lt; 0.05). SEM images demonstrated dentin erosion and the presence of residual medication in all groups. In conclusion, Bio-C Temp (Angelus) induces dentin chemical changes even after short exposure; however, a significant reduction in fracture resistance appears only after prolonged exposure.</p>