성견에서 저강도파동형초음파가 불량한 초기고정 임플란트의 골융합에 미치는 효과

Abstract

ABSTRACT

The effect of low intensity pulsed ultrasound on osseointegration of implant with poor primary stability in dogs

Kang Kyung Dong Advisor : Prof. Kim, Byung-ock, Ph.D. Department of Dentistry, Graduate School of Chosun University

Ultrasound has been proven to be an effective treatment for bone fracture healing, and lots of studies have confirmed its ability to enhance osteogenesis and facilitate bone regeneration, even though the mechanism of the mechanotransduction pathway associated with cellular responses to ultrasound is still not clear. The aim of this study wast to evaluate the effects of low intensity pulsed ultrasound (LIPUS) on the osseointegration of implants without initial stability in a canine model using histologic analysis, a histomorphometric method and a mobility test. Six, male mongrel dogs (17-19 ㎏) were included in this study. Right and left mandibular premolars were extracted. Four months after extraction, a total of 36 implants were placed bilaterally into the lower mandible. Holes, 3.5 mm in diameter, were drilled into the mandibular bone, and implants with a resorbable blasting media (RBM) surface, 3.3 mm in diameter and 8.5 mm in length, were placed into the holes. The implants placed into the holes were covered with resorbable membrane (Nano-gideⓇ, Nibec, Korea). The left side of each dog received LIPUS (IMPLASONIC, Dentis, Korea) application (15 minutes/day for 7 days), while the right side as a control received no treatment. The output of LIPUS was 3.0 ㎒ and 240 ㎽/㎠. This experiment was carried on for eight weeks and two dogs were sacrificed at 2-, 4- and 8-weeks. Prior to sacrificing the dogs, mobility tests (PeriotestⓇ values, PTVs, Siemens AG. Benssheim. Germany) were performed. After sacrificing the dogs, histologic and histomorphometric analysis were performed on the different groups of dogs. The histomorphometric analysis showed that the bone-implant contact percentages in the LIPUS group tended to be higher than that in the control group as the healing time passed. PTVs were considerably lower in the LIPUS group when compared to the control with the 4-week healing period group, and were negative in both groups at 8-week. And in the RBM implants, new bone was formed and in direct contact with the implant surface at 4-weeks. Mature bone was present after 8-weeks, irrespective of LIPUS application. Within the limit of this experiment, results indicate that LIPUS may have a positive effect on osseointegration and stability of dental implants, especially in early healing periods.