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Correlation between early perforation of cover screws and marginal bone loss: a retrospective study
Author(s) -
Van Assche Nele,
Collaert Bruno,
Coucke Wim,
Quirynen Marc
Publication year - 2008
Publication title -
journal of clinical periodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.456
H-Index - 151
eISSN - 1600-051X
pISSN - 0303-6979
DOI - 10.1111/j.1600-051x.2007.01158.x
Subject(s) - dentistry , medicine , implant , stage (stratigraphy) , perforation , radiography , gingival margin , orthodontics , surgery , materials science , paleontology , metallurgy , punching , biology
Aim: This retrospective study aimed to determine the consequence of early cover screw exposure on peri‐implant marginal bone level. Material and Methods: Sixty Astra Tech ® MicroThread implants installed in partially edentulous jaws were compared: 20 implants were placed following a two‐stage procedure and were unintentionally exposed to the oral cavity (two‐stage exposed), 20 implants were placed following a two‐stage procedure and were surgically exposed after a subgingival healing time of 3–6 months (two‐stage submerged), and 20 implants were placed following a one‐stage surgical protocol (one‐stage). Digital radiographs were taken at implant placement for all implants, and after abutment surgery for the two‐stage exposed and two‐stage submerged groups or after 3 months for the one‐stage group. Bone loss mesially and distally was measured with an on‐screen cursor after calibration. Results: Mean bone re‐modelling was 1.96 mm (range: 0.2–3.2 mm) around the two‐stage exposed implants, 0.01 mm (range: 0.0–0.3 mm) around the two‐stage submerged implants and 0.14 mm (range: 0.0–1.2 mm) around the one‐stage implants. Conclusion: The unintentional perforation of two‐stage implants resulted in significant bone destruction, probably because the biological width was not considered.