title: Ligature-induced peri-implant infection in crestal and subcrestal implants: a clinical and radiographic study in dogs.
abstract: Objective. The aim of this study was to assess the influence of implant-abutment interface (IAI) placement depths on peri-implant tissues in the presence of ligature-induced peri-implant inflammation. Materials and Methods. Two implants with screwed-in IAIs (SI) and two implants with tapped-in IAIs (TI) were inserted in one side of the mandible in six dogs eight weeks after tooth extraction. Four experimental groups were constituted: SI placed crestally, SI placed 1.5 mm subcrestally, TI placed crestally and TI placed 1.5 mm subcrestally. After 12 weeks, the healing abutments were connected. Four weeks later, cotton floss ligatures were placed around the abutments to promote plaque accumulation. Clinical and radiographic examinations were performed at 0, 6 and 12 weeks after ligature placement. The effects of the IAI placement depths on clinical and radiographic parameters were assessed. Results. The alterations of peri-implant probing depths, clinical attachment levels, distances from the IAI to the first bone-implant contact (IAI-fBIC) and depths of infrabony defect were significant larger in the subcrestal groups compared with the crestal groups during the plaque accumulation period. The alterations of clinical attachment levels, IAI-fBIC, depth of the infrabony defect and horizontal bone loss were not significantly different between the SI and TI groups after ligature placement. Conclusion. Tissue destruction in subcrestal implants may be more serious than that in crestal implants in the presence of inflamed peri-implant mucosa.
authors.affiliation: Department of Oral Implantology, Guanghua School of Stomatology, Hospital of Stomatology, Sun Yat-sen University , Guangzhou , China ; Guangdong Provincial Key Laboratory of Stomatology , Guangzhou , China ; Department of Periodontology, Peking University School and Hospital of Stomatology , Beijing , China.
authors.forename: Baoxin
authors.initials: B
authors.lastname: Huang
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology , Beijing , China ; The Second Dental Center, Peking University School and Hospital of Stomatology , Beijing , China.
authors.forename: Muzi
authors.initials: M
authors.lastname: Piao
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology , Beijing , China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology , Beijing , China.
authors.forename: Xian'e
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology , Beijing , China.
authors.forename: Li
authors.initials: L
authors.lastname: Xu
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology , Beijing , China.
authors.forename: Weidong
authors.initials: W
authors.lastname: Zhu
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology , Beijing , China.
authors.forename: Huanxin
authors.initials: H
authors.lastname: Meng
keywords: Animals; Bone resorption; Crestal remodeling; Dental implants; Dental implant–abutment design; Implant surface; Peri-implant defect; Peri-implantitis; Subcrestal positioning