Title: 1220 - Micromorphology of Radiation-Related Caries


Joslei Bohn (Presenter)
Universidade Federal do Paraná

Cassiano Chaiben, Universidade Federal do Paraná
Suzana Soares de Souza, Hospital Dr. Luiz Antônio
Regiane Maluf, Self Employee
Anelize Rumbelsperger, Universidade Federal do Parana
Angela Fernandes, Universidade Federal do Paraná
Antonio Soares de Lima, Universidade Federal do Paraná


Objectives: Radiation-related caries (RRC) is an aggressive and progressive form of dental caries. Clinically, it presents the brownish lesions in the cervical region of teeth in patients submitted to radiotherapy for head and neck tumors treatment. The aim of this study was to assess the morphology and chemical composition of RRC lesions.

Methods: Twenty-four human teeth were divided into three groups: G1CR (8 teeth with RRC), G2CC (8 teeth with conventional tooth decay) and G3HG (8 sound teeth). Morphology was evaluated with: periapical radiography, computerized tomography, computerized microtomography and scanning electron microscopy (roughness and topography). Chemical composition was evaluated by energy dispersive spectroscopy of X-ray.

Results: Results showed that there was more demineralization in RRC lesions when compared to conventional dental caries, even if there was no cavitation in cervical region of teeth. Surface roughness and topography of RRC were similar to those of sound teeth. On the other hand, conventional dental caries lesions presented greater superficial and topographic irregularity when compared to RRC and healthy teeth (p=0.001). Chemical composition analysis revealed a significant reduction of the amount of calcium and phosphorus between the three groups and increase in the amount of carbon. Mean of calcium and phosphorus was lower in G1CR when compared to G2CC and G3HG. Mean of carbon was higher in CRR teeth, lower in those with conventional caries and lower in healthy teeth.

Conclusions: A significant reduction of the mineral matrix (Ca and P) was consistent to the findings in the imaging tests, as there was a greater loss in teeth with RRC and slightly lower in the teeth with conventional tooth decay when compared to the sound teeth. According to the findings and despite its rapid evolution, it can be concluded that RRC presents an apparently intact surface with significant changes in amount of Ca, P and C.


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Ca (Wt%) 13,72 (±4,22) 18,77 (±2,47)
22,87 (±1,38)
P (Wt%) 6,77 (±2,02)
9,47 (±1,43)
11,72 (±0,47)
C (Wt%) 42,37 (±7,80)
32,99 (±4,38)
25,28 (±1,84)
Ca/C 0,35 (±0,17)
0,59 (±0,14)
0,91 (±0,12)
Ca/P 2,02 (±0,04)
1,99 (±0,06)
1,95 (±0,05)

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE