title: Chronological changes in the microstructure of bone during peri-implant healing: a microcomputed tomographic evaluation.
abstract: Our objectives were to examine the titanium-bone interfaces chronologically and to clarify the process of osseointegration using microcomputed tomography (microCT). The mandibular premolars of 3 dogs were extracted and 12 weeks later 2 Straumann dental implants were installed in each quadrant. The microstructural changes at the bone-implant interface at the first, fourth, and eighth weeks after installation were evaluated by microCT and a 3-dimensional image was constructed. The microstructural measurements at the bone-implant interface, including the trabecular number (Tb.N), bone volume fraction (BV/TV), structure model index (SMI), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp) and connectivity density (Conn.D), were measured. Experimental outcomes were analysed for correlations between time and microstructural variables of trabecular bone. Tb.N increased significantly during the eighth week compared with that during the first and fourth week (p=0.001, 0.002). BV/TV increased generally with time and there were significant differences (p=0.003) between each time group. While Tb.Sp decreased with time and changed significantly during the eighth week compared with that during the first week (p=0.021), differences in SMI, Tb.Th and Conn.D did not differ significantly according to time of implant. The significant increase in the Tb.N and BV/TV during the eighth week after insertion of implants indicates that the formation of new bone before the eighth week is the key to osseointegration.
authors.affiliation: Department of Head and Neck Surgery, Sir Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, P.R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Fang
authors.affiliation: Department of Stomatology, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China. Electronic address: dingxi@wzhospital.cn.
authors.forename: Xi
authors.initials: X
authors.lastname: Ding
authors.affiliation: School/Hospital of Stomatology, Zhejiang University, Hangzhou, Zhejiang, China. Electronic address: wangmysm@yahoo.com.cn.
authors.forename: Hui-ming
authors.initials: HM
authors.lastname: Wang
authors.affiliation: Department of Oral and Maxillofacial Surgery, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang Province, China. Electronic address: zhuxinghao@hotmail.com.
authors.forename: Xing-Hao
authors.initials: XH
authors.lastname: Zhu
mesh_terms: D000818:Animals; D001641:Bicuspid / Q000601:surgery; D015519:Bone Density / Q000502:physiology; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry; D004285:Dogs; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging* / Q000648:ultrastructure; D009929:Organ Size; D016348:Osseointegration / Q000502:physiology*; D010012:Osteogenesis / Q000502:physiology; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D036542:Tomography, Spiral Computed / Q000379:methods; D014081:Tooth Extraction / Q000379:methods; D020390:Tooth Socket / Q000000981:diagnostic imaging / Q000648:ultrastructure; D014945:Wound Healing / Q000502:physiology; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D014025:Titanium
keywords: Dental implants; Implant-bone interface; Micro-computed tomography (microCT); Microstructure