Patterns of Demineralization and Dentin Reactions in Radiation-Related Caries

Silva, A.R.S.; Alves, Fábio Abreu; Antunes, Alberto Nogueira da Gama; Goes, M F De; Lopes, Márcio Ajudarte

doi:10.1159/000192799

Cited by 109 publications

(134 citation statements)

References 38 publications

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“…However, oral cancer patients exposed to radiotherapy demonstrate post-radiation dental lesions that initiate with enamel shear fracture that can result in partial to total enamel delamination, suggesting DEJ instability (Jongebloed et al, 1988;Pioch et al, 1992;Jansma et al, 1993). While postradiotherapy dentition breakdown has been linked to radiation-induced salivary gland damage (Vissink et al, 2003a;Kielbassa et al, 2006;Silva et al, 2009), our group completed a clinical study and reported a significant correlation between pathologic enamel loss and individual tooth-level radiation dose in oral cancer patients (Walker et al, 2011). Three tiers of tooth response were observed: at < 30 Gray (Gy), minimal tooth damage occurred; between 30 and 60 Gy, there was a 2 to 3x increased risk of tooth breakdown (salivary gland impact); and at > 60 Gy, there was a 10x increased risk of tooth damage, indicating radiation-induced damage to the tooth in addition to salivary gland damage.…”

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confidence: 99%

Type IV Collagen is a Novel DEJ Biomarker that is Reduced by Radiotherapy

McGuire¹,

Gorski

Dusevich³

et al. 2014

J Dent Res

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The dental basement membrane (BM) is composed of collagen types IV, VI, VII, and XVII, fibronectin, and laminin and plays an inductive role in epithelial-mesenchymal interactions during tooth development. The BM is degraded and removed during later-stage tooth morphogenesis; however, its original position defines the location of the dentinenamel junction (DEJ) in mature teeth. We recently demonstrated that type VII collagen is a novel component of the inner enamel organic matrix layer contiguous with the DEJ. Since it is frequently co-expressed with and forms functional complexes with type VII collagen, we hypothesized that type IV collagen should also be localized to the DEJ in mature human teeth. To identify collagen IV, we first evaluated defect-free erupted teeth from various donors. To investigate a possible stabilizing role, we also evaluated extracted teeth exposed to high-dose radiotherapy -teeth that manifest post-radiotherapy DEJ instability. We now show that type IV collagen is a component within the morphological DEJ of posterior and anterior teeth from individuals aged 18 to 80 yr. Confocal microscopy revealed that immunostained type IV collagen was restricted to the 5-to 10-µm-wide optical DEJ, while collagenase treatment or previous in vivo tooth-level exposure to > 60 Gray irradiation severely reduced immunoreactivity. This assignment was confirmed by Western blotting with whole-tooth crown and enamel extracts. Without reduction, type IV collagen contained macromolecular α-chains of 225 and 250 kDa. Compositionally, our results identify type IV collagen as the first macromolecular biomarker of the morphological DEJ of mature teeth. Given its network structure and propensity to stabilize the dermal-epidermal junction, we propose that a collagen-IV-enriched DEJ may, in part, explain its wellknown fracture toughness, crack propagation resistance, and stability. In contrast, loss of type IV collagen may represent a biochemical rationale for the DEJ instability observed following oral cancer radiotherapy.

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confidence: 99%

Type IV Collagen is a Novel DEJ Biomarker that is Reduced by Radiotherapy

McGuire¹,

Gorski

Dusevich³

et al. 2014

J Dent Res

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“…1,2 Although the exact nature of RRC has not been completely understood, it can be considered as a complex and multifactorial disease related to the direct and indirect effects of radiation on the salivary glands and teeth. [3][4][5][6][7][8] Despite recent advances in radiation therapy and implementation of multidisciplinary approaches, the oral environment of patients who undergo head and neck therapy still poses a clinical challenge for dentistry. Therefore, a better understanding of carious development in patients with cancer could be useful for the improvement of clinical management.…”

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confidence: 99%

“…3 Optical coherence tomography (OCT) is a nondestructive imaging technique using low-coherence interferometry to determine the time delay and magnitude of backscattered light reflected off a transparent and semitransparent structure. 9 By using the optical properties of reflection and scattering into sound and carious mineralized tissues, it is possible to evaluate and characterize morphological structures as the CEJ and DEJ.…”

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confidence: 99%

Optical Coherence Tomography as an Auxiliary Tool for the Screening of Radiation-Related Caries

Mota

Gueiros

Maia

et al. 2013

Photomedicine and Laser Surgery

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Objective: The aim of this study was to evaluate the morphological alterations of radiation-related caries using optical coherence tomography. Methods: Thirty-six extracted teeth from 11 patients who had undergone radiotherapy were sectioned in the sagittal axis in the center of the carious lesion, and 100 lm thick sections were obtained from each specimen. One sample from each tooth was investigated by an optical coherence tomography (OCT) system, and the results were compared with histological images from polarized light microscopy. Results: In OCT dentin caries images, the demineralized area appeared as a white region, whereas the translucent zone appeared as a dark area, a similar pattern also seen in coronal caries. In noncavitated enamel lesions clinically observed as brown discoloration, the area of high porosity, and also the dark color, absorbs part of the light, resulting in a dark pattern. Finally, the involvement of dentin-enamel junction (DEJ) or cement-enamel junction (CEJ) could be clearly observed, when present and marked alterations along the CEJ could be noted, as junction continuity loss, gap formation, and mineral loss tissue. Conclusions: The OCT technique was able to characterize radiation-related caries, from a morphological point of view. Also demonstrated was its potential benefit for use in the clinical monitoring of radiation-related carious process.

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“…This phenomenon could be caused by the fact that patients affected by radiation-related caries do not present dental pain on a routine basis. Several hypotheses suggest that the direct effects of radiation on the dental pulp would be able to negatively affect the metabolism of odontoblasts and compromise the response of the dentin-pulp complex to the progression of radiation related caries, explaining the absence of pain even in deep carious lesions (3,11). However, other studies do not support direct radiation damage to the innervation of the pulp that would be able to negatively affect the viability of odontoblasts, the repair capacity of dentin against caries progression, and the inhibition of pulp sensitivity and responses to caries progression (10,12,13).…”

Section: Discussion:-mentioning

confidence: 99%