Detecting demineralization of enamel and cementum after gamma irradiation using radiographic densitometry

Abstract

The purpose of this study was to evaluate the ability of radiographic densitometry in detecting the early demineralization of human enamel and cementum in irradiated and non-irradiated teeth. Sixty extracted teeth were divided into two groups: irradiated group and non-irradiated group. After irradiation, the groups were subjected to demineralization-remineralization (PH) cycling. Radiographic densitometric measurements (gray values) of a selected area of interest in the enamel and in the cementum of each tooth were performed at baseline and after PH cycling. After PH cycling, there was a significant reduction in gray values for both groups. The difference between "baseline" and "after PH cycling" values represents the reduction in the mineral content of the hard tissue, i.e., the demineralization. Results show that the demineralization of irradiated tooth enamel and cementum was significantly higher compared to that of non-irradiated tissues as determined by gray-level values. It is concluded that densitometric measurements by means of digital radiographs allow for the detection of demineralization of enamel and cementum, and can be used successfully for diagnosis of the early carious lesions in patients who received head and neck radiotherapy. This will allow implementation of remineralizing therapy and avoid the risk of progression of radiation caries. Furthermore, it is concluded that gamma irradiation with typical therapeutic doses for head and neck carcinoma is a direct cause of demineralization of tooth enamel and cementum.

Os impactos da radioterapia na estrutura dental e suas consequências no tratamento odontológico

“…A porcentagem do volume mineral do esmalte foi dependente das doses de radiação mostrando desmineralização gradual com um aumento na exposição à radiação de 20 para 80Gy. Essa desmineralização pode ser explicada pelo processo de descarboxilização e a perda de fosfatos ácidos quando o esmalte é irradiado (Abdalla et al, 2018). A exposição do esmalte a 80Gy causou uma diminuição da microdureza do esmalte que está relacionada à perda percentual de volume mineral e um aumento simultâneo na densidade mineral, qual se deve à variação na matriz cristalina de hidroxiapatita (Kudkuli et al, 2020).…”

Manifestation and Mechanisms of Abnormal Mineralization in Teeth

“…139 Gamma irradiation at therapeutic doses for treating head and neck carcinoma causes demineralization of tooth enamel. 141 The radiation caries that subsequently develops is rapidly progressing and severely destructive. This is because the nanomechanical properties of enamel (decreased nano hardness, elastic modulus, increased friction coefficient) are adversely affected by gamma irradiation.…”

“…Biofilm control for maintaining relatively healthy homeostasis of dental plaque biofilms has been proposed to prevent caries . Gamma irradiation at therapeutic doses for treating head and neck carcinoma causes demineralization of tooth enamel . The radiation caries that subsequently develops is rapidly progressing and severely destructive.…”

Tratamiento de caries relacionada a radiación: una revisión de literatura

“…La etiologıá de caries relacionada a radiación es la combinación de efectos indirectos de la radioterapia, como el daño en las glándulas salivares que por consecuencia produce cambios en la �lora bucal y reduce la remineralización, daño en la articulación temporomandibular y músculos de la masticación ocasionando trismo, daño a nivel de las mucosas produciendo mucositis limitando una correcta higiene bucal; sumados a los efectos directos que esta produce sobre la estructura del diente (3,5) , como cambios en la micro dureza, composición quıḿica y micro morfologıá del esmalte y la dentina (6,7) , predisponiendo a un incremento de riesgo de caries. Se diferencia de la caries convencional porque eśta se desarrolla rápidamente, es muy destructiva y en su mayorıá indolora (3,(8)(9)(10) . Afecta principalmente la región cervical, cerca de la unión entre la corona y la raıź (4) e incluye caries a nivel de dentina radicular (11) .…”