Microradiographic and microscopic studies on in situ induced initial caries in irradiated and nonirradiated dental enamel

The objective of this study was to evaluate the onset of initial deminerali zation in irradiated and nonirradiated human enamel. Enamel specimens were prepared from the lingual and buccal surfaces of 48 freshly extracted, cari es-free third molars. Either the lingual or the buccal enamel specimen of e ach tooth was irradiated with 60 Gy, The remaining enamel sample was not ir radiated. Two irradiated and two nonirradiated enamel specimens were insert ed into both buccal aspects of each 12 intraoral mandibular appliances. The appliances were worn by 12 persons for 6 weeks throughout day and night. O ne side was brushed daily with a fluoride-free toothpaste. On the other sid e plaque was allowed to grow. Individual oral hygiene techniques were perfo rmed without any fluorides. During meals, the appliance was stored in 10% s ucrose solution. The enamel specimens were cut perpendicular to the enamel surface. Subsequently, the slabs were ground to a thickness of 90 mu m, and studied by means of TMR and microscopic techniques. Evaluated data did not show any differences between irradiated and nonirradiated enamel lesions ( ANOVA), The onset of caries in irradiated enamel can be hampered by regular ly performed oral hygiene techniques, Copyright (C) 2000 S. Karger AG, Base l.