The objective of this study was to evaluate the effects of irradiation on microhardness of dentin. Dentin blocks from the cervical region of bovine incisors were treated as follows: (1) no irradiation; (2) irradiation of specimens up to 60 Gy (2 Gy/day, 5 days/week); (3) no irradiation, but fluoridation of specimens for 5 min/d; (4) irradiation of specimens and daily fluoridation. Knoop hardness number (KHN) of the control specimens was 62.63 ±14.75 (mean ± SD). This was significantly different from the irradiated dentin samples (8.74 ± 2.59 KHN). Hardness of the fluoridated dentin specimens was 11.19 ± 1.95 KHN in the non‐irradiated group and 10.03±2.76 KHN in the irradiated groups, respectively. Within the limitations of an in vitro study, it is concluded that dentin is severely affected by irradiation. This could be an explanation for the frequently observed side‐effects of irradiation like loss of enamel, gap formation at the amelodentinal junction, and caries of the cervical region. Fluoridation with acidic gels decreases microhardness of dentin surface, and does not prevent softening due to radiation, when saliva is absent.

The objective of this study was to evaluate the onset of initial demineralization in irradiated and nonirradiated human enamel. Enamel specimens were prepared from the lingual and buccal surfaces of 48 freshly extracted, caries–free third molars. Either the lingual or the buccal enamel specimen of each tooth was irradiated with 60 Gy. The remaining enamel sample was not irradiated. Two irradiated and two nonirradiated enamel specimens were inserted into both buccal aspects of each 12 intraoral mandibular appliances. The appliances were worn by 12 persons for 6 weeks throughout day and night. One side was brushed daily with a fluoride–free toothpaste. On the other side plaque was allowed to grow. Individual oral hygiene techniques were performed without any fluorides. During meals, the appliance was stored in 10% sucrose solution. The enamel specimens were cut perpendicular to the enamel surface. Subsequently, the slabs were ground to a thickness of 90 μm, 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 regularly performed oral hygiene techniques.

Purpose Radiation dermatitis (RD) represents one of the most frequent side effects in radiotherapy (RT). Despite technical progress, mild and moderate RD still affects major subsets of patients and identification and management of patients with a high risk of severe RD is essential. We sought to characterize surveillance and nonpharmaceutical preventive management of RD in German-speaking hospitals and private centers. Methods We conducted a survey on RD among German-speaking radiation oncologists inquiring for their evaluation of risk factors, assessment methods, and nonpharmaceutical preventive management of RD. Results A total of 244 health professionals from public and private institutions in Germany, Austria, and Switzerland participated in the survey. RT-dependent factors were deemed most relevant for RD onset followed by lifestyle factors, emphasizing the impact of treatment conceptualization and patient education. While a broad majority of 92.8% assess RD at least once during RT, 59.0% of participants report RD at least partially arbitrarily and 17.4% stated to classify RD severity solely arbitrarily. 83.7% of all participants were unaware of patient-reported outcomes (PROs). Consensus exists on some lifestyle recommendations like avoidance of sun exposure (98.7%), hot baths (95.1%), and mechanical irritation (91.8%) under RT, while deodorant use (63.4% not at all, 22.1% with restrictions) or application of skin lotion (15.1% disapproval) remain controversial and are not recommended by guidelines or evidence-based practices. Conclusion Identification of patients at an increased risk of RD and subsequent implementation of adequate preventive measures remain relevant and challenging aspects of clinical routines. Consensus exists on several risk factors and nonpharmaceutical prevention recommendations, while RT-dependent risk factors, e.g., the fractionation scheme, or hygienic measures like deodorant use remain controversial. Surveillance is widely lacking methodology and objectivity. Intensifying outreach in the radiation oncology community is needed to improve practice patterns.

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