The Impact of Radiotherapy in the in Vitro Remineralization of Demineralized Enamel

Abstract

Objective: To evaluate the impact of radiotherapy on enamel around restorations of glass ionomer cement (GIC) and fluoride tooth paste (FTP). Material and Methods: Eighty enamel blocks were made and randomly distributed into two groups, according to the fluoride therapy, non-fluoride tooth paste (NFTP) and FTP (n=40) and in subgroups in conformity with radiation dose (0, 10, 30 and 60 Gy). Roughness and microhardness enamel analyses were conducted before radiotherapy. Enamel cavities were made and restored with two GIC (Ketac Molar Easy Mix or Vitremer). Enamel blocks were submitted to 10, 30 and 60 Gy. Then, artificial enamel caries lesions were created by a pH-cycling procedure and FTP or NFTP were used as treatment. The restored enamel blocks were submitted to final roughness and microhardness analyses. Roughness increase (∆R) and hardness loss (∆H) values of enamel were submitted to ANOVA and Tukey test (p=0.05). Results: The irradiated enamel group showed statistically higher ∆R (0.44 ±0.2) and ∆H (99.26±7.0) values compared to non-irradiated group (∆R = 0.051±0.02; ∆H=66.16±12.7) when a resin-modified GIC and NFTP were used. Conclusion: Higher radiation dose increased dissolution of bovine enamel. The use of GIC associated with FTP decreased roughness and increased enamel hardness after radiotherapy.

Effect of Diode Laser and Remineralizing Agents on Microstructure and Surface Microhardness of Therapeutic Gamma-Irradiated Primary Teeth Enamel

“…Yet, the mechanism of RC had not been precisely described. In this study, a single radiation dose of 60 Gy was used [24], which is the maximum cumulative dose provided to children suffering from HNC. In clinical practice, the fractions were given for 6 weeks, 5 days/week [26], [28].…”

“…This step was executed in the National Center for Radiation Research and Technology, at the Atomic Energy Authority (NCRRT), Cairo, Egypt, using (60 co, Baha, Baha Indian Cobalt: 60-4000A) as a gamma source, at a dose rate of 0.806 KGy/h at the time of irradiation. A simulated therapeutic dose of 60 Gy was administered as a single dose [24], which is the therapeutic dose of HNC patients [25], [26]. All enamel specimens -except those of Group C -were exposed to therapeutic gamma irradiation, while immersed in plastic containers filled with distilled water [27].…”

Effects of ionizing radiation on surface properties of current restorative dental materials

“…In this context, studies report that gamma radiation therapy affects the glass ionomers and the resin composite properties [20][21][22]. It has been demonstrated that gamma radiation increased the microhardness of a glass ionomer cement [23] and can produce free radicals that may improve the microhardness of resin-based materials such as conventional resin composites [24].…”