The work presents a surface plasmon resonance biosensor employing bismuth telluride (Bi2Te3) and graphene layer overlaid on the Ag metal layer-based biosensor to detect disease in the teeth. The Ag layer, Bi2Te3, and graphene are assumed to have thicknesses of 35 nm, 1 nm, and 0. 5 nm, respectively. Using single-layer Bi2Te3 and single-layer graphene, the highest sensitivity of the sensor for enamel, dentin, and cementum is 79.310 deg/RIU, 118.88 deg/RIU, and 169.87 deg/RIU obtained, respectively. The other performance parameters are full width at half maximum, detection accuracy, and quality factor obtained as 6.723 deg, 0.11 deg−1, and 18.74 RIU−1. Graphene increases the biocompatibility of the analyte with the sensing layer. Consideration has been given to the aqueous solution as a sensing medium. The proposed sensor has great potential in the medical and chemical fields.