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

Renally Bezerra Wanderley E Lima,Sônia Saeger Meireles,Rosângela Marques Duarte,Ana Karina Maciel Andrade,Maria Luiza Pontual

doi:10.4034/pboci.2019.191.18

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.

Highlights

In the recent years, the number of oral and oropharyngeal cancer cases has increased [1].Patients that have been diagnosed with oral cancer can be treated by several treatment methods such as radiotherapy [2,3], surgery [4], chemotherapy [2,3] or by the combination thereof
The ∆R values of bovine enamel around glass ionomer cement restorations were statistically higher for the irradiated groups (10, 30 and 60 Gy) compared to the control group (0 Gy), when non-fluoride tooth paste (NFTP) was used
Bovine enamel presented statistically lower ∆R values after the use of fluoride tooth paste (FTP) compared to NFTP for every ionizing radiation doses in both dental cements

Summary

Introduction

The number of oral and oropharyngeal cancer cases has increased [1].Patients that have been diagnosed with oral cancer can be treated by several treatment methods such as radiotherapy [2,3], surgery [4], chemotherapy [2,3] or by the combination thereof. When no preventive treatment is performed, an excessive damage of the dentition is commonly seen within the first year after the patient undergoes the radiation therapy [9]. This form of dental caries is a complex and multifactorial disease [10,11] and is related to many factors such as the radiogenic damage of the salivary glands, leading to post-radiation hyposalivation, the increase of cariogenic bacteria, poor oral hygiene and the intake of a more cariogenic diet after HNRT [10,12]. There is limited and contradictory information regarding the direct effects of HNRT on the dental structure, causing RRC in the tooth enamel and dentin [10,1521]

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Discussion

Conclusion