Changes in human mandibular bone morphology after heat application

Abstract

Purpose Intraosseous heat development is always a problem during bone surgery performed using rotary burs and ultrasound devices. However, only few data exist regarding the morphological effects of applied heat on bone surfaces. Methods We used 24 human mandibular bone specimens of the mental region from six body donators. Three body donators were fixed in ethanol and the others were stored frozen. Heat application to the bone surfaces at temperatures of 40 °C, 50 °C, 60 °C and 100 °C for 1 min respectively, was performed under controlled conditions using an iron heater, and followed by examination using (i) scanning electron microscopy (SEM), (ii) demineralized paraffin sections, and (iii) cryostat sections (both HE staining). Results There was no difference in the morphology or histology between fixed or unfixed bone specimens. The bone surface was smooth in both groups at 40 °C and 50 °C of heat application. Applications of 60 °C and 100 °C induced a rough-textured surface with small cavities visible with SEM and demineralized HE staining. The bone appeared to be unaffected at lower planes. The frozen HE histology could not be evaluated. Although useful in other studies, here the sections were broken and displaced on the glass slide. Therefore, this technique is not recommended by the authors. Conclusion Our findings suggest the applicability of SEM for bone surface morphology and demineralized paraffin sections (HE staining) for frontal plane evaluation. Fixed and non-fixed bone specimens seem to be equal in their morphology and can both be used in these kinds of studies.