The Excessive Loss of Branemark Fixtures in Type IV Bone: A 5‐Year Analysis

TLDR

Branemark implant success is generally high in the maxilla and mandible, but fixture loss can be influenced by many factors, with bone quality—particularly the thin cortex and low trabecular density of Type IV bone—being a key determinant. Presurgical determination of Type IV bone may be one method to decrease implant failure. In a 5‑year analysis of 1,054 implants, only 3 % of those placed in Types I–III bone failed, whereas 35 % of implants in Type IV bone were lost, underscoring bone quality as the main risk factor. J Periodontol 1991; 62:2–4.

Abstract

T he predictability of branemark implants has been well documented. High success rates in the maxilla and mandible in fully and partially edentulous patients can be expected. A host of factors may be attributed to the etiology of fixture loss. However, the quality of bone stands out as the single greatest determinant in fixture loss. Types I, II, and III bone offer good strength. Type IV bone has a thin cortex and poor medullary strength with low trabecular density. Ninety percent of 1,054 implants placed were in Types I, II, and III bone. Only 3% of these fixtures were lost; of the 10% of the fixtures placed in Type IV bone, 35% failed. Presurgical determination of Type IV bone may be one method to decrease implant failure. J Periodontol 1991; 62:2–4 .