Date of Award
Summer 2019
Document Type
Thesis - Restricted
Degree Name
Master of Science (MS)
Department
Dentistry
First Advisor
Liu, Dawei
Second Advisor
Toth, Jeffrey M.
Third Advisor
Ahuja, Bhoomika
Abstract
Introduction: Vibration in the form of high frequency, low magnitude acceleration has paradoxical effects on craniofacial bones – with anabolic effects under physiological conditions and catabolic effects in the presence of inflammation. The objectives of this study are to establish a murine model for periodontitis and to investigate the effects of high frequency, low magnitude mechanical vibration on alveolar bone following ligature- induced experimental periodontitis.Materials and Methods: Ninety-five 11-week-old inbred strain C57BL/67 male mice were randomly assigned into four groups: 1) healthy control (n = 9); 2) healthy + mechanical vibration (n = 8); 3) experimental periodontitis + no treatment (n=7); and 4) experimental periodontitis + vibration (n = 9). All mice in the disease groups had ligature‐induced experimental periodontitis induced for 8 days to generate localized alveolar bone loss. In mechanical vibration treatment groups, the mice received high frequency mechanical vibration (60 Hz, 0.3g) for 5min/day on the maxillary right first molar for consecutive 7 and 21 days respectively to determine the effects on alveolar bone following experimental periodontitis. Micro computed tomography (micro-CT) was used to quantify new bone formation through bone volume fraction (BVF), bone mineral density (BMD), and crestal bone heights post treatment with or without mechanical vibration. For each of the parameters, one-way ANOVA was used to determine a statistically significant difference among the 5 experimental groups, with Bonferroni comparison being used to measure significance between each 2 groups (p < 0.05 is considered significant).Results: Experimental periodontitis resulted in significant reductions in BVF, TMD and alveolar bone height compared to healthy controls. Treatment with mechanical vibration for 21 days led to a non-significant, local anabolic effect, but also resulted in statistically significant decreases in BVF and TMD of alveolar bone adjacent to the site of application of mechanical vibration.Conclusion: Mechanical vibration (60Hz, 0.3g, 5min/day) modestly increased bone volume and density when applied directly to the tooth, indicating a potential clinical application for improving bone quantity and quality following periodontitis.