Evaluation of a device for attenuation of electron release from dental restorations in a therapeutic radiation field.
BACKGROUND
For some patients, radiation treatment is a part of tumor therapy in the head and neck area before and/or after surgery. The oral cavity and teeth are thereby frequently exposed to high doses of radiation. In this situation, electronic backscatter from dental materials may damage the surrounding soft tissue.


OBJECTIVE
This study determined the degree of absorption and the backscatter effect of therapeutic radiation used in the presence of 4 different dental materials. The efficacy of a protective stent also was investigated.


METHODS
The influence of 4 dental materials (a high-gold alloy, pure titanium, amalgam, and a synthetic material) on radiation dose distribution was tested on 2 test models that simulated the presence of teeth. An alanine dosimeter was used to make measurements with and without the presence of a protective stent. To verify the results, one of the test models was compared to a computer simulation.


RESULTS
Backscatter effects on the surface of dental materials caused an increase of up to 170% of the radiation dose measured without the materials. The rate of overdose increased with the atomic number of the dental material. The extent of the backscatter effect was a maximum of 4 mm.


CONCLUSIONS
The considerable overdose of 170% found in this study suggests that soft tissue surrounding dental restorations should be protected from radiation. The backscatter results indicate that soft tissue could be effectively shielded with a 3-mm synthetic stent.
Reitemeier
Bernd
B
Department of Prosthodontic Dentistry, Medical Faculty Carl Gustav Carus, Technical University of Dresden, Dresden, Germany. bernd-reitemeier@excite.com
Reitemeier
Gottfried
G
Schmidt
Annette
A
Schaal
Wolfgang
W
Blochberger
Peter
P
Lehmann
Dietmar
D
Herrmann
Thomas
T
D000042:Absorption; D000180:Acrylic Resins / Q000528:radiation effects; D000409:Alanine; D003188:Composite Resins / Q000528:radiation effects; D003198:Computer Simulation; D003723:Dental Amalgam / Q000528:radiation effects; D003764:Dental Materials / Q000528:radiation effects*; D003793:Dental Restoration, Permanent; D004583:Electrons; D006047:Gold Alloys / Q000528:radiation effects; D006801:Humans; D008954:Models, Biological; D009010:Monte Carlo Method; D009061:Mouth Mucosa / Q000528:radiation effects; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation; D011874:Radiometry / Q000295:instrumentation; D011878:Radiotherapy; D011879:Radiotherapy Dosage; D012542:Scattering, Radiation; D015607:Stents; D014025:Titanium / Q000528:radiation effects
D000180:Acrylic Resins; D003188:Composite Resins; D003764:Dental Materials; D006047:Gold Alloys; D003723:Dental Amalgam; C069714:Protemp; D014025:Titanium; D000409:Alanine