The effect of radiotherapy on dental hard tissue--a systematic review

Decay of teeth, erosion and disintegration of hard dental tissue are a clinically often seen side effect after radiotherapy for tumours in the head and neck region. To investigate if these side effects are due to structural changes in dental hard tissues, the current literature was searched. It can influence the quality of life gravely.

A systematic PubMed (Medline) search was done and of the 374 hits, 11 articles were included. During the reading of these articles, 10 additional useful references to other articles were retrieved. An extra search was done on "A.M. Kielbassa", a key writer in many articles on this subject. Four extra articles were found. So in total, 25 articles were analysed in this systematic review.

Tooth destruction occurs often and soon after irradiation. There is no difference between decay in irradiated and non-irradiated teeth. The locations and the progressiveness of the destruction are different in irradiated then in non-irradiated teeth. Several studies show changes in the structure and micro hardness of enamel, the dentinoenamel junction (DEJ) and dentin. The biomechanical properties are dramatically decreased. The odds of moderate/severe tooth damage increased with the irradiation dose.

In conclusion the results of this systematic review show a great amount of changes and damages at all levels of the hard dental tissues, enamel, DEJ and dentin. These findings substantiate the idea that the formation of recurrent and atypical patterns of dental caries in irradiated teeth is, not only due to loss of saliva but a combination of both hyposalivation and the direct effects on hard dental tissue. The formation of atypical caries is furthermore increased due to poor oral hygiene, the increase of soft and carbohydrate-rich substance and changes of the bacterial micro flora and proteins.

This article is written to understand more about the cause of destruction of teeth after radiotherapy. This way, a more adequate preventive and restorative treatment plan can be drawn up for an individual patient.