High-frequency vibration (HFV) to enhance socket preservation in anticipation of implant placement: case reports — part 1

Drs. David W. Engen, Gregori M. Kurtzman, and Tarek El-Bialy discuss the rationale for using HFV

Introduction

In implant dentistry, having adequate bone is imperative to the success of treatment. Patients lose teeth for a variety of reasons, including trauma, nonrestorable decay, endodontic involvement, and periodontal disease.  When the decision is made that a tooth must be extracted and that the final goal is a dental implant, two of the major considerations are ridge/socket preservation and ridge/socket augmentation in preparation for the future dental implant. Socket preservation also becomes a consideration when fixed prosthetics will be placed over the edentulous site or when removable non-implant prosthetics is planned.

Ridge or socket preservation can be presented in many forms depending on the nature of the defect. If the socket is well preserved, the socket may simply be allowed to heal on its own. Araujo and Lindhe showed processes of modeling and remodeling during socket healing that resulted in qualitative and quantitative changes at the edentulous site over an 8-week period. The study reported that dimensional alterations of the alveolar ridge that occurred following tooth extraction as well as bone modeling and remodeling are associated with such change. The study found marked dimensional alterations during the first 8 weeks following the extraction of mandibular premolars. During this time, a marked osteoclastic activity resulted in resorption of the crestal region of both the buccal and the lingual bone wall. The reduction of the height of the walls was more pronounced at the buccal than at the lingual aspect of the extraction socket.

Alternatively, post-extraction, the socket may be cleaned of any residual tissue associated with the failed tooth and preserved with a membrane over the top to prevent tissue ingress and to promote clot formation; ultimately, bone growth within the socket will result. Another option is to augment the socket with a collagen plug to act as a scaffold to the blood clot that will form in the socket.³ Finally, the gold standard would be bone augmentation using either human, bovine, or synthetic materials and covering the site with a membrane.^4,5

Overall, 25 systematic reviews conclude that ridge preservation reduces post-extraction bone loss and decreases between 55% to 100% of the need for further treatment.  Ridge preservation techniques are effective in reducing ridge resorption with varying levels of success.^6-29 Some of these include coronal advancement of a buccal flap, rotating grafts from tissue adjacent to cover the defect, or using free gingival or subepithelial connective tissue grafts.

A new, novel approach has been suggested to use high-frequency vibration (HFV) to stimulate bone growth. In preclinical studies, HFV has demonstrated a significant increase in osteoblasts and fibroblasts within the periodontal ligament. A study by Alansari, et al., noted that HFV increased the concentration of growth factors such as bone morphogenetic protein (BMP) and platelet-derived growth factor (PDGF).³¹ Another study found that HFV could potentially enhance osseointegration of implants.³²  Alikhani demonstrated an increase in bone volume and an ability for HFV to preserve alveolar bone width and height.³³  In a recent case study by Hallas, HFV was used as adjunctive therapy in ridge augmentation in preparation for future implant placement.³⁴

Five patients who are being presented all underwent extraction, followed by a healing period prior to allowing implant placement. The sites were each treated by healing without socket grafting to allow organization of the resulting clot and bone fill prior to implant placement. The patients were all premedicated with 500 mg Amoxicillin 3 times daily, beginning the night before the extraction. Following extraction of the tooth, the sockets were thoroughly degranulated and a post-extraction CBCT was taken. All five patients had an extraction, with no socket augmentation and were given an HFV device (VPro™, Propel Orthodontics) used for 5 minutes daily post-extraction until the sites were ready for implant placement. The patients returned 4 to 6 months later at which time another CBCT (pre-implant) was taken for site comparison purposes. The dental implants were placed. These patients were informed that should the HFV not produce sufficient bone for their future implant that any post-test, pre-implant bone grafting necessary would be performed at no additional charge.

Part 2 of this two-part article will review the five patient cases that follow what has been discussed here. The patients were examined by CBCT immediately following extraction, wherein density was determined (Hounsfield units) for the extraction socket and a reference at the adjacent cortical bone of the socket wall. Following a 4- to 6-month healing period (patient specific), a new CBCT was acquired, and a density determination was taken at the same spot in the extraction socket as in the prior CBCT scan as well as the same adjacent point on the cortical socket wall. The reference point was used to confirm that the cortical density was similar in both scans so that a determination of the effects of HFV on the socket contents could be ascertained and confirm whether the area increased in density. The results confirm that HFV has a positive effect on bone formation and increases its density, accelerating socket bone maturation.