Journal of Oral Implantology February 2014 - (Page 53)

RESEARCH Removal Torque Analysis of Implants in Rabbit Tibia After Topical Application of Simvastatin Gel Fatima Neves Faraco-Schwed, DDS, MD, PhD1* Luiz Macedo Mangueira, DDS, MS2 Joao Vitor Albuquerque Ribeiro, DDS1 Alexsandro Da Silva Antao, DDS1 Jamil Awad Shibli, DDS, MD, PhD3 The aim of this study was to evaluate the effects of topical application of simvastatin gel (7.5 mg) on the removal torque of titanium implants in the rabbit tibia. A total of 32 surgeries were performed on 16 New Zealand rabbits for the placement of 2 implants in 1 tibia of each rabbit. Only 1 of the surgical defects was injected with 30 mg/mL of simvastatin gel before implant placement. The initial torque was set at 20 N.cm, and removal torque testing was performed 28 and 56 days postoperatively with a Tonishi torque wrench. Surgical defects were divided into 4 groups: group IG-28 (test, 28 days), group IG-56 (test, 56 days), group I-28 (control, 28 days), and group I-56 (control, 56 days). Removal torque values were higher in group IG-56 than in groups IG28, I-28, and I-56 (P , .05). Groups IG-28, I-28, and I-56 showed similar values (P . .05). Removal torque force increased under the influence of simvastatin, indicating that topical administration of a 7.5-mg dose of simvastatin gel is effective in improving the torque force required to remove implants inserted in the rabbit tibia. Key Words: statin, removal torque, dental implants INTRODUCTION A dvances in research on the treatment of hyperlipidemia in the mid-1980s culminated in the development of a revolutionary class of drugs: the statins or vastatins. These lipid-lowering drugs can reduce low-density lipoprotein levels by 29%, reaching a 60% reduction in cholesterol levels in some cases.1-3 All statins share the ability to inhibit endogenous cholesterol synthesis by competitively inhibiting 3-hydroxyl-3-methylglutaryl coenzyme A (HMG-CoA) reductase, thus preventing the conversion of HMG-CoA reductase to mevalonate. On the other hand, statins can increase bone mineral density, reducing the risk of osteoporosis and fracture.4-6 1 ˜ Paulista University (UNIP), Sao Paulo, SP, Brazil. ˜ Santo Amaro University (UNISA), Sao Paulo, SP, Brazil. ˜ Guarulhos University, Sao Paulo, SP, Brazil. * Corresponding author, e-mail: fatimafaraco@terra.com.br DOI: 10.1563/AAID-JOI-D-11-00128 2 3 Topical statins alone and/or associated with a vehicle that slows their intestinal absorption and hepatic metabolism, such as gel, stimulate bone formation by acting on the mRNA synthesis of bone morphogenetic protein-2 (BMP-2), which promotes osteoblast proliferation and differentiation. Since this mechanism precedes the increase in BMP-2 mRNA expression, statins may also promote angiogenesis.4-6 Bone morphogenetic protein-2, a member of the transforming growth factor-beta family, may have direct effects on adjacent cells (paracrine effect) and/or act on osteoblasts (autocrine effect), thus aiding bone regeneration over a long period of time. This protein may progress into a component of bone remodeling over a long time, thus enhancing the pattern of bone mineral density.7 Statins have also been demonstrated to induce osteoclast apoptosis and to inhibit bone resorption in vitro; after in vivo treatment, they promote a decrease in osteoclast numbers.8,9 It is therefore Journal of Oral Implantology 53

Table of Contents for the Digital Edition of Journal of Oral Implantology February 2014

Evolution of Bone Grafting for Improved Predictability
Electrochemical Behavior of Titanium in Artificial Saliva: Influence of pH
Efficacy of Antibacterial Sealing Gel and O-Ring to Prevent Microleakage at the Implant
Wired/Classic and Wireless/Periotest ‘‘M’’ Instruments: An In Vitro Assessment of
Altered Position of the Medial Lingual Nutritional Foramina at Different Stages of Alveolar
Genotoxicity of Endosseous Implants Using Two Cellular Lineages In Vitro
Implants With Internal Hexagon and Conical Implant-Abutment Connections: An In Vitro
Stress Distribution Around Maxillary Anterior Implants as a Factor of Labial Bone Thickness
Peri-Implant Biomechanical Responses to Standard, Short-Wide, and Mini Implants
Removal Torque Analysis of Implants in Rabbit Tibia After Topical Application of
Nonprocessed Adipose Tissue Graft in the Treatment of Peri-Implant Osseous Defects in
Assessment of the Effect of Two Occlusal Concepts for Implant-Supported Fixed
Nerve Damage Assessment Following Implant Placement in Human Cadaver Jaws:
Dental Implants: Early Versus Standard Two-Stage Loading (Animal Study)
Intravenous Sedation for Implant Surgery: Midazolam, Butorphanol, and
Nanocrystalline Hydroxyapatite-Based Material Already Contributes to Implant Stability
Two Neglected Biologic Risk Factors in Bone Grafting and Implantology: High Low-Density

Journal of Oral Implantology February 2014