The effect of spatial distances between holes and time delays between bone drillings based on examination of heat accumulation and risk of bone thermal necrosis

Abstract

Background and objective This study was designed to investigate heat accumulation and bone thermal necrosis for various distances between holes and time delays between drillings. Methods The tests were performed at three distances (6, 12, 16 mm) and three time delays: 0, 5 and 10 s. To examine the efficiency of coolants, CO 2 coolant was also tested in addition to two common cooling modes in bone drilling. Results The main results were the trend of temperature–time graph, maximum temperature at drilling site, temperature distribution on the surface of drilling site, temperature durability and returning time. The effect of lateral drillings on the initial hole was notable in drilling at a distance of 6 mm without cooling. This effect did not disappear even by increasing the time delay up to 10 s. The results obtained for drilling with normal saline coolant were not sufficiently acceptable due to the manual and non-uniform cooling process as well as the relative obstruction of the chips exit path. Generally, drillings with two common cooling modes, even when the distances between holes and time delays between drillings were controlled, did not yield all favorable conditions for preventing bone thermal necrosis. Conclusion Bone drilling using CO 2 coolant eliminates the risk of bone thermal necrosis completely even in cases that the distances between holes in plates or implants are 6 mm and there is no time delay between drillings. These results can be especially useful in emergency orthopedic surgeries and for designing the location of screw holes in implants and plates.

The effect of electromagnetic field on decreasing and increasing of the growth and proliferation rate of dermal fibroblast cell

“…Considering the effects of EMF on the gene expression and necrosis of cells, 12,[36][37][38] the effects of EMF exposure are suggested to be investigated for the fibroblastic cells in future studies. As all the experiments in the present study were performed at a frequency of 50 Hz, the effects of frequency change both on increasing and reducing the growth rate of skin fibroblasts can be further studied.…”

Finite element analysis of occlusal splint therapy in patients with bruxism

“…It is worth noting that due to personal limitations of the patients, it was only possible to create the 3D model of jaw, teeth and splint of 10 women and 11 men after 6 months of using splint. Since the analyses based on FEM are among the most familiar methods for biological simulation [28][29][30][31][32][33][34][35][36][37][38][39][40][41], the assembled models were transferred finally to ABAQUS software version 6.14 (Dassault Systemes) for FE analysis. Furthermore, for comparing the results of computer simulations in patients and control subjects and also for comparing the results in patients before and after the occlusal splint therapy, three specific anatomical points of the skull of samples were used as set points to synchronize the procedures and to standardize the samples' head position.…”

Finite element analysis of occlusal splint therapy in patients with bruxism

“…women and 11 men after 6 months of using splint. Since the analyses based on FEM are among the most familiar methods for biological simulation [28][29][30][31][32][33][34][35][36][37][38][39][40][41], the assembled models were transferred finally to ABAQUS software version 6.14 (Dassault Systemes) for FE analysis. Furthermore, for comparing the results of computer simulations in patients and control subjects and also for comparing the results in patients before and after the occlusal splint therapy, three specific anatomical points of the skull of samples were used as set points to synchronize the procedures and to standardize the samples' head position.…”