Evaluation of the Relationship Between Marginal Bone Loss and Implant Angulation in All-on-Four System

Abstract

Purpose: The All-on-four concept is a reliable treatment modality for severely atrophic jaws. The aim of this study is to investigate the correlation between the marginal bone loss, length, and angulation of tilted implants inserted for full-arch rehabilitation according to the All-on-four concept using cone-beam computer tomography (CBCT) images. Material and Methods: A retrospective study was conducted based on medical records including clinical and radiographical data of dental implant patients treated between September 2017 and September 2023. The patients were treated with dental implants according to the All-on-four concept with the same dental implant brand. Patients without any systemic conditions, non-smokers, and patients who received immediate prosthetic rehabilitation were included in this study. From the CBCT images, the average marginal bone loss was compared between implants according to their angle-length measurement. Results: The mean follow-up time was 32.7±16.9 months. The angulation of the axial implants was between 73.07 to 98.41 degrees and lateral implants were tilted 50.45 to 86.46 degrees. The marginal bone loss increased as the angle of the implant increased. The resorption rate was not affected by gender, age, and follow-up duration. Conclusion: Regarding this study’s findings, it can be stated that the wide range of different implant angulations in the All-on-four concept is well tolerated in physiologic limits regarding marginal bone loss, thus it is a successful procedure for rehabilitation of edentulous patients. However, care must be taken for follow-ups and the cooperation of the patient is crucial for the prognosis.

Keywords

• All-on-four
• Implant agulation
• Marginal Bone Loss
• Marginal Bone Loss

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