Can chlorhexidine and fluoride mouthwashes mitigate the effect of gamma irradiation therapy damage to enamel and dentin?
A new study that looked at the effectiveness of mouthwash protocols in preventing gamma irradiation therapy damage to the ultimate tensile strength (UTS) of enamel and dentin yielded mixed results (Journal of Dental Research, May 2011, Vol. 90:5, pp. 659-664).
The researchers -- from two Brazilian universities -- divided 120 teeth into two groups. One group underwent irradiation (subjected to 60 Gy of gamma irradiation in daily increments of 2 Gy), while the other didn't.
They were then subdivided into two mouthwash protocols used three times per day: 0.12% chlorhexidine, 0.05% sodium fluoride, and control group. The specimens were evaluated by microtensile testing. Macromolecular alterations were suggested by optical retardation data in dentin. Structural alterations were detected by scanning electron microscopy analysis.
The gamma irradiation therapy significantly reduced the UTS of the enamel, crown, and root dentin, the researchers found.
"The mouthwash with 0.12% chlorhexidine partially prevented the damage to the mechanical properties of the irradiated crown dentin, whereas the 0.05% sodium-fluoride-irradiated enamel showed UTS similar to that of nonirradiated enamel," the authors concluded.
