Functional Bone Response for Angulated Placed Implants Compared to Straight Implants

Objectives: The objectives of this study was to evaluate the functional bone response for angulated placed implants compared to straight implants.
Methods: The study was approved by Ethical Commitee of Murcia University, Spain. Six Fox Hound dogs have been used in this experiment. 3 premolars and the first molar of each dog were extracted and 4 conventional implants (Medentika Implants GmbH, Huegelsheim; Germany) were immediately inserted straight and 4 newly designed tilted implant (Medentika Implants GmbH) were inserted in a 30 degree angulation. In the first group immediate loading was performed with a bar. In the second group the implants were inserted in the extraction sockets and after 3 months of healing the implants were loaded with a bar for another 3 months. Radiographs were obtained following implant installation, and after 3 and 6 months. The animals were sacrificed and biopsies were prepared for histological analysis.
Results: The radiographic analysis revealed the largest amount of bone loss following implant installation. This loss was more pronounced at implants without immediate loading. The bone level alterations observed at implants exposed to 3 months of functional load were small and did not differ significantly between the groups. The histological analysis revealed an average Bone-to-Implant Contact (BIC) of 63.48% with values between 43.39% to 92.05%. Implants exposed to functional load exhibited a higher degree of BIC than control implants without loading. There was no significant difference in bone loss regarding the newly designed tilted implants placed in a 30 degree angulation compared to the conventional implants placed straight.
Conclusions: Based on the results it can be concluded that the newly designed tilted implants placed in a 30 degree angulation show similar bone maintenance compared to conventional implants placed straight. It is suggested that functional load at implants may result in higher marginal bone stability.