Clinical Evaluation of Dental Metal Hazards and Therapeutic Effects of Shortwave Diathermy in Dental Medicine

Abstract

ABSTRACT Objective Shortwave diathermy causes increase in temperature from deep inside the body, results in upregulation of metabolism, and has analgesic effects. In this study, we explored the potential application of shortwave diathermy in the maxillofacial region by monitoring internal and external temperature changes, changes in blood flow, and resting saliva secretion under shortwave diathermy for subjects with and without dental metal restorations (MR) to confirm the safety and the limitation of shortwave diathermy for dental medicine. Materials and methods Twenty young healthy subjects were recruited (10 subjects with MR and 10 subjects without MR). Shortwave exposure was achieved with condenser-type probes placed on the bilateral mandibular angles, and the intraoral temperature was monitored. For functional analysis, unstimulated whole saliva before and after exposure was collected. The temperature and blood flow distributions of the exposed areas were then monitored by thermography and twodimensional (2D) laser Doppler flowmetry. Results Shortwave exposure for 20 minutes induced significant temperature increases in all groups (p ≤ 0.05). The subjects reported no discomfort. When subjects without MR held gold or titanium crowns in their mouths, the thermal effect by shortwave diathermy was reduced. Resting saliva upon exposure only increased significantly in metal-free subjects, and amylase concentration was also increased, but the level of the salivary stress biomarker chromogranin A was unchanged. Furthermore, thermography showed that shortwave diathermy significantly increased the surface temperature for cheek skin and the buccal mucosa; however, this increase failed to elevate surface blood flow. Conclusion Shortwave diathermy induces temperature increases in the maxillofacial region. MR did not cause excessive heating, on the contrary, reduce the thermal effect of shortwave radiation. The temperature rise maintains upregulation in salivary function, which could be utilized safely in dental medicine. How to cite this article Mukai C, Nakamoto T, Kondo Y, Masaki C, Ohta A, Hosokawa R. Clinical Evaluation of Dental Metal Hazards and Therapeutic Effects of Shortwave Diathermy in Dental Medicine. Int J Prosthodont Restor Dent 2012;2(3): 88-95.