• Pravej Serichetaphongse
• Pimnara Sitthikhunkitt
• Sunantha Srisubat-Ploysongsang

Objective To investigate the scattered radiation at bone-implant interfaces irradiated with a therapeutic radiation dose from three different dental implant surfaces in human bone model.

Materials and methods Dry human mandible was used to measure the dose enhancement caused by scattered radiation from the three different implant surfaces [machined surface, titanium -coated (TiUnite) surface, hydroxyapatite (HA) -coated surface]. Radiation dose enhancement at distance of 0, 1, 2, and 3 mm from bone-implant interface was determined by thermoluminescent dosimetry using lithium fluoride single crystal chips as a radiation absorber. The absorbed radiation doses in the lithium fluoride chips at mesial, distal, buccal and lingual directions around dental implant were measured and compared using three-way ANOVA.

Results The HA-coated surface implant had the lowest scattered radiation at 0, 1, and 2 mm from the bone-implant interface. There was a statistically significant difference of scattered radiation between both HA-coated and TiUnite implant surface to machined implant surface at 0 mm from the bone-implant interface (p < .05). There was no statistically difference of dose enhancement between mesial, distal, buccal and lingual directions (p > .05).

Conclusion HA-coated surface implant demonstrated the lowest scattered radiation among three surfaces tested in dry human mandible. There was no significant difference in scattered radiation at 2 and 3 mm from the bone-implant interface for all the implant surfaces studied. There was no statistical difference of dose enhancement between mesial, distal, buccal and lingual direction. There was no cumulative effect of scattered radiation from the adjacent implant which placed at 7 mm distance (surface to surface).

(CU Dent J. 2004;27:235-246)