Dental implant fracture is a rare biomechanical complication, however, one of the most serious and frustating ones as it is generally associated with implant and prosthesis failure as well as the surgical hazards of explantation and reimplantation. To gain insights into implant fracture rates and the impact of patient-, surgery-, and prosthetic-related factors, systematic review and meta-analysis of the English literature were performed. Electronic and hand searches yielded 69 relevant publications reporting on 827 fractures out of 44521 implants investigated. The overall incidence of implant fractures was 1.6%. Mean patient age at the time of implant fracture was 54 ± 11 years, and 70% occurred in males. The vast majority (85%) occurred in posterior regions of the mouth (premolar or molar positions). No tendency of increased fracture rates could be noted for short implant lengths or narrow implant diameters. Implant fractures occurred after 4.1 ± 3.5 years of loading, on average, in most cases (88%) supporting fixed restorations; however, only 56% were preceded by screw loosening. Although further investigations are needed to fully explore the characteristics and causes of this rare complication, it can be concluded that no more than 2.8% of implants fracture is within a mean loading period of 8.3 years. 1. Introduction Rehabilitation of the incomplete dentition by means of osseointegrated dental implants represents a highly predictable and widespread therapy [1]. Despite its high success rate, dental implant therapy—in the long term—is not free of complications [2] even though early failure rates of modern rough-surfaced implants of at least 10？mm in length are as low as 0.7% [3]. While early losses are predominantly due to lack of establishment of osseointegration, there are two main reasons for late implant failures [4]: loss of supporting tissue (secondary to infection or peri-implantitis) and mechanical problems (such as biomechanical overload or implant fracture). Possible causes of implant fracture include inadequate fit of the superstructure, defects in the production or design of the material, long-term metal fatigue, magnitude or direction of occlusal forces, parafunctional habits, implant location, implant length, implant diameter, and bone resorption around the implant. The clinical crown-to-implant ratio naturally increases with marginal bone loss, resulting in even greater biomechanical load. In many cases, however, fractures due to bone resorption and bone resorption due to factures are hard to distinguish in retrospect. In a recent
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