RADIATION EFFECT ON STRUCTURE AND MECHANICAL PROPERTIES OF TEETH- AN INVITRO STUDY

Mithra N Hegde*, Nidarsh D Hegde, Suchetha Kumari N, Ganesh Sanjeev, Priya

ABSTRACT

Objectives: Evaluating the effects of radiation therapy on enamel and dentin by performing microhardness test and Scanning Electron microscopy (SEM) studies. Methods: Vickers hardness test was performed for extracted teeth sections (n=16 hemisections) on outer enamel region and 3 regions on dentin layer (superficial, intermediary and deep). The hardness values were obtained before radiation therapy and after 70 Gy beam treatment. The values obtained were analyzed statistically by performing paired‘t’ test and one way ANNOVA followed by tukey’s test. SEM analysis (n=6 hemisections) was carried out to study the changes in morphology of Enamel and dentin after radiation. Results: The hardness values showed a steady decrease in each portion of enamel and dentin of the radiated teeth. The test values were found significant at p< 0.001. The SEM images showed demarcation of prisms, dentinal tubules in non-radiated teeth samples whereas the tissue differentiation was a critical task in radiated samples due to degradation of the components. Conclusions: The ionizing radiation is found highly effective in damaging the dental tissues at the dosage rate of 70 Gy. It reduces the mechanical strength of the tissues and also causes morphological changes developing cracks which can lead to variety of dental challenges. Clinical significance: Radiation Therapy can serve as an onset for development of dental caries or loss of whole tissue. Hence preventive measures are necessary to be taken in case of high dosed radiation therapy among head and neck cancer.

Keywords: Radiation therapy, Enamel, Dentin, Microhardness, Surface analysis.