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

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


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.


Dental Enamel; Glass Ionomer Cements; Hardness Tests; Radiotherapy

Full Text:



Oral Cancer Foundation [homepage]. Newport Beach (Ca): Oral Cancer Foundation; 2015. Available at: [Accessed on Aug. 27, 2017]

Lyons A. Current concepts in the management of oral cancer. Dent Update 2006; 33(9):538-45.

Lazarus C, Logemann JA, Pauloski BR, Rademaker AW, Helenowski IB, Vonesh EF, et al. Effects of radiotherapy with or without chemotherapy on tongue strength and swallowing in patients with oral cancer. Head Neck 2007; 29(7):632-7.

Hong SX, Cha IH, Lee EW, Kim J. Mandibular invasion of lower gingival carcinoma in the molar region: its clinical implications on the surgical management. Int J Oral Maxillofac Surg 2001; 30(2):130-8.

Pradier O, Hille A, Schmidberger H, Hess CF. Monitoring of therapy in head and neck patients during the radiotherapy by measurement of Cyfra 21-1. Cancer Radiother 2002; 6(1):15-21.

Beumer J, Curtis TA, Marunick MT. Maxillofacial Rehabilitation, Prosthodontic and Surgical Considerations. St. Louis: Ishiyaku EuroAmerica, Inc, 1996. 546p.

Brown LR, Dreizen S, Handler S, Johnston DA. Effect of radiation-induced xerostomia on human oral microflora. J Dent Res 1975; 54(4):740-50.

Pyykönen JG, Malmström M, Oikarinen VJ, Salmo M, Vehkalahti M. Late effects of radiation treatment of tongue and floor of mouth cancer on the dentition, saliva secretion, mucous membranes and lower jaw. Int J Oral Maxillofac Surg 1986; 15(4):401-9.

Dreizen S, Brown LR, Daly TE, Drane JB. Prevention of xerostomia-related dental caries in irradiated cancer patients. J Dent Res 1977; 56(2):99-104.

Kielbassa AM, Hellwig E, Meyer-Lückel H. Effects of irradiation on in situ remineralization of human and bovine enamel demineralized in vitro. Caries Res 2006; 40(2):130–135.

Silva ARS, Alves FA, Antunes A, Goes MF, Lopes MA. Patterns of demineralization and dentin reactions in radiation-related caries. Caries Res 2009; 43(1):43-9.

Vissink A, Jansma J, Spijkervet FK, Burlage FR, Coppes RP. Oral sequelae of head and neck radiotherapy. Crit Rev Oral Biol Med 2003; 14(3):199-212.

Marx RE, Stern D. Oral and Maxillofacial Pathology: A Rationale for Diagnosis and Treatment. 2nd. ed. Chicago: Quintessence Inc. 2002. pp. 380-338.

Jansma J, Buskes JA, Vissink A, Mehta DM, Gravenmade EJ. The effect of X-ray irradiation on the demineralization of bovine dental enamel. A constant composition study. Caries Res 1988; 22(4):199-203.

Pioch T, Golfels D, Staehle HJ. An experimental study of the stability of irradiated teeth in the region of the dentinoenamel junction. Endod Dent Traumatol 1992; 8(6):241-4.

Madrid CC, de Pauli Paglioni M, Line SR, Vasconcelos KG, Brandão TB, Lopes MA, Santos-Silva AR, De Goes MF. Structural analysis of enamel in teeth from head-and-neck cancer patients who underwent radiotherapy. Caries Res 2017; 51(2):119-28.

Marangoni-Lopes L, Rovai-Pavan G, Steiner-Oliveira C, Nobre-Dos-Santos M. Radiotherapy reduces microhardness and mineral and organic composition, and changes the morphology of primary teeth: An in vitro study. Caries Res 2018; 53(3):296-304.

Joyston-Bechal S. The effect of X-radiation on the susceptibility of enamel to an artificial caries like attack in vitro. J Dent 1985; 13(1):41-4.

Kielbassa AM, Schendera A, Schulte-Monting J. Microradiographic and microscopic studies on in situ induced initial caries in irradiated and nonirradiated dental enamel. Caries Res 2000; 34(1):41-7.

Zhang X, Li YJ, Wang SL, Xie JY. Effect of irradiation on tooth hard tissue and its resistance to acid. Zhonghua Kou Qiang Yi Xue Za Zhi 2004; 39(6):463-6.

Bekes K, Francke U, Schaller HG, Kuhnt T, Gerlach R, Vordermark D, Gernhardt CR. The influence of different irradiation doses and desensitizer application on demineralization of human dentin. Oral Oncol 2009; 45(9):e80-4.

Silva AR, Alves FA, Berger SB, Giannini M, Goes MF, Lopes MA. Radiation-related caries and early restoration failure in head and neck cancer patients. A polarized light microscopy and scanning electron microscopy study. Support Care Cancer 2010; 18(1):83-7.

Galetti R, Santos-Silva AR, Antunes AN, Alves F de A, Lopes AM, de Goes MF . Radiotherapy does not impair dentin adhesive properties in head and neck cancer patients. Clin Oral Invest 2014; 18(7):1771-8.

Smales RJ, Gao W. In vitro caries inhibition at the enamel margins of glass ionomer restoratives developed for the ART approach. J Dent 2000; 28(4):249-56.

Wiegand A, Buchalla W, Attin T. Review on fluoride-releasing restorative materials - Fluoride release and uptake characteristics, antibacterial activity and influence on caries formation. Dent Mater 2007; 23(3):343-62.

Wood RE, Maxymiw WG, McComb D. A clinical comparison of glass ionomer (polyalkenoate) and silver amalgam restorations in the treatment of class 5 caries in xerostomic head and neck cancer patients. Oper Dent 1993; 18(3):94-102.

McComb D, Erickson RL, Maxymiw WG, Wood RE. A clinical comparison of glass ionomer, resin-modified glass ionomer and resin composite restorations in the treatment of cervical caries in xerostomic head and neck radiation patients. Oper Dent 2002; 27(5):430-7.

De Moor R J G et al. Two-year clinical performance of glass ionomer and resin composite restorations in xerostomic head and neck-irradiated cancer patients. Clin Oral Invest 2011; 15(1):31-3.

Rodrigues JA, Marchi GM, Serra MC, Hara AT. Visual evaluation of in vitro cariostatic effect of restorative materials associated with dentifrices. Braz Dent J 2005; 16(2):112-8.

Zach GA. X-ray diffraction and calcium-phosphorous analysis of irradiated human teeth. J Dent Res 1976; 55(5):907-9.

Gonçalves LM, Palma-Dibb RG, Paula-Silva FW, Oliveira HF, Nelson-Filho P, Silva LA, et al. Radiation therapy alters microhardness and microstructure of enamel and dentin of permanent human teeth. J Dent 2014; 42(8):986-92.

Cole T, Silver AS. Production of hydrogen atoms in teeth by X-irradiation. Nature 1963; 200:700-1.

Palmier NR, Madrid CC, Paglioni MP, Rivera C, Martins BNFL, Araújo ALD, et al. Cracked tooth syndrome in irradiated patients with head and neck cancer. Oral Surg Oral Med Oral Pathol Oral Radiol 2018; 126(4):335-41.e2.

Fränzel W, Gerlach R, Hein HJ, Schaller HG. Effect of tumor therapeutic irradiation on the mechanical properties of teeth tissue. Z Med Phys 2006; 16(2):148-54.

Owosho AA, Yom SK, Han Z, Sine K, Lee NY, Huryn JM, Estilo CL. Comparison of mean radiation dose and dosimetric distribution to tooth-bearing regions of the mandible associated with proton beam radiation therapy and intensity-modulated radiation therapy for ipsilateral head and neck tumor. Oral Surg Oral Med Oral Pathol Oral Radiol 2016; 122(5):566-71.

Soares CJ, Castro CG, Neiva NA, Soares PV, Santos-Filho PC, Naves LZ, Pereira PN. Effect of gamma irradiation on ultimate tensile strength of enamel and dentin. J Dent Res 2010; 89(2):159-64.

Vieira AE, Delbem AC, Sassaki KT, Rodrigues E, Cury JA, Cunha RF. Fluoride dose response in pH-cycling models using bovine enamel. Caries Res 2005; 39(6):514-20.

Silva RC, Zuanon ACC. Surface roughness of glass ionomer cements indicated for Atraumatic Restorative Treatment (ART). Braz Dent J 2006; 17(2):106-9.

Papagiannoulis L, Kakaboura A, Eliades G. In vivo vs in vitro anticariogenic behavior of glass-ionomer and resin composite restorative materials. Dental Mat 2002; 18(8):561-9.

Amaral MT, Guedes-Pinto AC, Chevitarese O. Effects of a glass-ionomer cement on the remineralization of occlusal caries - An in situ study. Braz Oral Res 2006; 20(2):91-6.

Hu JY, Smales RJ, Li YQ, Yip KH. Restoration of teeth with more-viscous glass ionomer cements following radiation-induced caries. Int Dent J 2002; 52(6):445-8.