Influence of a Machined Collar on Crestal Bone Changes Around Titanium Implants: A Histometric Study in the Canine Mandible

Autor: David L. Cochran, Joachim S. Hermann, Archie A. Jones, Lara G. Bakaeen, John Schoolfield, Daniel Buser
Rok vydání: 2011
Předmět:
Zdroj: Journal of Periodontology. 82:1329-1338
ISSN: 1943-3670
0022-3492
DOI: 10.1902/jop.2011.090728
Popis: Background: It has been shown that peri-implant crestal bone reactions are influenced by both a rough–smooth implant border in one-piece, non-submerged, as well as an interface (microgap [MG] between implant/abutment) in two-piece butt-joint, submerged and non-submerged implants being placed at different levels in relation to the crest of the bone. According to standard surgical procedures, the rough–smooth implant border for implants with a smooth collar should be aligned with the crest of the bone exhibiting a smooth collar adjacent to peri-implant soft tissues. No data, however, are available for implants exhibiting a sandblasted, large-grit and acid-etched (SLA) surface all the way to the top of a non-submerged implant. Thus, the purpose of this study is to histometrically examine crestal bone changes around machined versus SLA-surfaced implant collars in a side-by-side comparison. Methods: A total of 60 titanium implants (30 machined collars and 30 SLA collars) were randomly placed in edentulous mandibular areas of five foxhounds forming six different subgroups (implant subgroups A to F). The implants in subgroups A to C had a machined collar (control), whereas the implants in subgroups D to F were SLA-treated all the way to the top (MG level; test). Furthermore, the MGs of the implants were placed at different levels in relation to the crest of the bone: the implants in subgroups A and E were 2 mm above the crest, in subgroups C and D 1 mm above, in subgroup B 3 mm above, and in subgroup F at the bone crest level. For all implants, abutment healing screws were connected the day of surgery. These caps were loosened and immediately retightened monthly. At 6 months, animals were sacrificed and non-decalcified histology was analyzed by evaluating peri-implant crestal bone levels. Results: For implants in subgroup A, the estimated mean crestal bone loss (– SD) was -0.52 – 0.40 mm; in subgroup B, +0.16 – 0.40 mm (bone gain); in subgroup C, -1.28 – 0.21 mm; in subgroup D, -0.43 – 0.43 mm; in subgroup E, -0.03 – 0.48 mm; and in subgroup F, -1.11 – 0.27 mm. Mean bone loss for subgroup A was significantly greater than for subgroup E (P = 0.034) and bone loss for subgroup C was significantly greater than for subgroup D (P
Databáze: OpenAIRE
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