Three Year Randomized Split Mouth Clinical Trial Comparing Marginal Bone Loss Around Implants with a Conical or Straight Collar Design

(Pages: 16-24)

Alessandro Luigi Rossi1, David Palombo1,2, Alberto Clivio1 and Matteo Chiapasco1

1Unit of Oral Surgery – Department of Health Sciences – Santi Paolo&Carlo Hospital, University of Milan, Italy; 2Department of Periodontology, University Complutense of Madrid, Madrid, Spain




Abstract: Background: The influence of the implant design on the development of marginal peri-implant bone loss, is still a controversial topic.
Aim: to compare marginal bone loss between 2 implants with a conical or straight collar, provided with identical surfaces, connections, diameters and lengths.
Material & Methods: Ten patients presenting with single tooth symmetric posterior edentulous spaces, received a straight collar implant in one site (OsseoSpeed TX 5.0 S Astra Tech Implant System), and a conical collar implant in the symmetric contralateral one (OsseoSpeed TX 5.0, Astra Tech Implant System). Patients were followed-up for 36 months to evaluate: a) marginal peri-implant bone loss; b) implant survival and success rates according to Albrektsson et al. (1986); c) peri-implant probing depth (PD) and bleeding on probing (BOP).
Results: Mean marginal bone loss was 0.19 mm and 0.13 mm in the test (conical implant) and control group (straight implant), respectively. No statistically significant differences were observed among the two groups (α=0,05). Implant success was 100% in both groups.
Conclusions: large diameter implants with a straight or conical implant collar design are equally reliable in the rehabilitation of single tooth posterior edentulous spaces.

Keywords: : Implant design, straight implant, conical implant, marginal bone loss.