Extracorporeal Shock Wave Therapy as a Helpful Method for Rapid Osseointegration of Dental Implants: Animal Study

Abstract

The aim of this study was to assess the multi-phasic use of extracorporeal shock wave therapy (ESWT) as an adjuvant treatment to accelerate the osseointegration of titanium dental implants. Initially, twelve titanium mini-screws were inserted in femur bones of six New Zealand rabbits in three groups; the one-time treated group, the three-time treated group, and the control group (without ESWT). Then, 1800 focused shockwaves with an energy flux density of 0.3 mJ/mm² in every phase were used. Fourteen days after the last phase of ESWT, the animals were sacrificed to assess the osseointegration of screws via micro-computed tomography scan (micro-CT scan), biomechanical pull-out test, and histopathological analysis. Pull-out and histopathology analysis showed that the ESWT significantly increased bone regeneration and osseointegration around the implants compared to the control group (p < 0.05). Moreover, the pull-out test confirmed that the three-time treated screws needed more force to pull the bone out compared to the other two groups (p < 0.05). The mean bone volume fraction between the control group, the one-time treated group, and the three-time treatment group were not statistically significant (p > 0.05) according to the micro-CT scan results. Based on our results, ESWT can be suggested as a non-invasive and cost-effective adjuvant for osseointegration of dental implants. However, more in vivo studies and clinical trials are needed for validation of this finding.

Keywords: bone regeneration; bone volume fraction; dental implants; extracorporeal shockwave therapy; osseointegration.

Figure 1

(A,B): insertion of the screw in rabbit femur. It was made sure that all screws were inserted unicortically with a proper primary stability.

Figure 2

After pulling out the screw from the bone. Newly regenerated bone is visible on the screw threads.

Figure 3

Micro computed tomography cuts of samples. The number of samples have been written under each sample. Radiolucencies around screw threads are due to drilling size, which gave us a slight micro defect around screws to assess the bone regenerating process.

Figure 4

Rabbit histology of bone formation. (A,B): control group; (C,D): One-time treated group; (E,F): Three-time treated group. There was normal histology of bone matrix (m), Volkmann’s canals (v), and osteocytes (o), associated with no inflammation and bone necrosis in all experimental groups. Arrows are indicating bone formation zones, which were more severe in Three-time treated group compared to One-time treated group. There were mature and immature bone formations simultaneous in Three-time treated group (H&E). Regions of active ossification and newly formed bone are indicated by arrows in subfigure (A–D).