Dosimetric evaluation of the effect of dental implants in head and neck radiotherapy.
OBJECTIVE
The aim of the study was to examine the dose enhancement from scattered radiation at bone-dental implant interfaces during simulated head and neck radiotherapy.


METHODS
Four cylindrical titanium dental implants with 3 different sizes and lengths were implanted into a human mandible in 4 different positions. Ionization measurements for 6 MV X, 25 MV X, and Co-60 gamma rays were done. Thermoluminescent dosimeter (TLD 100 ) chips were used to measure radiation dose enhancement due to the scattered electrons from titanium and electronic disequilibrium at the tissue-metal interface.


RESULTS
The results showed that for Co-60, there is a 21% maximum increase in dose to alveolar mandibular bone at the close proximity to the titanium. For 6-MV x-rays the dose enhancement increase was almost the same or slightly lower than for Co-60, while for 25-MV high-energy x-rays, dose enhancement was lower than that of others. This increase in dose enhancement fell off rapidly and became insignificant at 2 mm from the interface.


CONCLUSIONS
Total dose that may lead to osteoradionecrosis risk of the mandible is slightly but not significantly affected by the scattered dose of the dental implants of lower jaw in the radiation field exposed to 3 different radiation beams.
Ozen
Julide
J
Department of Prosthetic Dentistry, Gülhane Military Medical Academy, Ankara, Turkey. julideozen@yahoo.com <julideozen@yahoo.com>
Dirican
Bahar
B
Oysul
Kaan
K
Beyzadeoglu
Murat
M
Ucok
Ozlem
O
Beydemir
Bedri
B
D002102:Cadaver; D003037:Cobalt Radioisotopes; D016371:Cranial Irradiation; D003759:Dental Implantation, Endosseous, Endodontic; D015921:Dental Implants; D005720:Gamma Rays; D006801:Humans; D008334:Mandible / Q000528:radiation effects*; D019047:Phantoms, Imaging; D011879:Radiotherapy Dosage; D011882:Radiotherapy, High-Energy / Q000706:statistics & numerical data; D012542:Scattering, Radiation; D013819:Thermoluminescent Dosimetry; D014025:Titanium
D003037:Cobalt Radioisotopes; D015921:Dental Implants; D014025:Titanium