Longitudinal changes in tooth/single-implant relationship and bone topography: an 8-year retrospective analysis.
OBJECTIVE
To evaluate longitudinal changes in tooth/implant relationship and bone topography at single implants with a microthreaded, conical marginal portion (Astra Tech ST® implants, Astra Tech AB, Mölndal, Sweden).


METHODS
Thirty-one subjects with single implant-supported restorations in the esthetic zone were included. Radiographs obtained at crown installation and 1, 5, and 8 years of follow-up were analyzed with regard to changes in (1) bone level at the implant and adjacent teeth and (2) vertical position of adjacent teeth relative to the single implant.


RESULTS
The mean marginal bone loss amounted to 0.1 mm at both implants and adjacent teeth during the 8 years of follow-up. Regression analysis failed to identify significant explanatory factors for observed variance in bone level change at the adjacent tooth surfaces. Vertical change in position of the teeth relative to the implants was more frequent and significantly greater in incisor compared with premolar tooth region but not associated with gender or age.


CONCLUSIONS
The marginal bone level at teeth adjacent to single implants with a microthreaded conical marginal part was not influenced by horizontal and vertical tooth-implant distances. Continuous eruption of adjacent teeth may result in infraocclusal positioning of a single-implant restoration.
Chang
Moontaek
M
Department of Periodontology, Institute of Odontology, The Sahlgrenska Academy at University of Gothenburg, Göteborg, Sweden. chang@chonbuk.ac.kr
Wennström
Jan L
JL
D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology*; D001641:Bicuspid / Q000503:physiopathology*; D003442:Crowns; D019250:Dental Implants, Single-Tooth / Q000009:adverse effects; D003769:Dental Occlusion, Traumatic / Q000209:etiology*; D017267:Dental Prosthesis Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007180:Incisor / Q000503:physiopathology*; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008437:Maxilla; D008875:Middle Aged; D011859:Radiography; D012189:Retrospective Studies; D014078:Tooth Eruption; D055815:Young Adult