Recommended by Dr. med. dent. Karin Wolleb Torrisi
Insights from this study for clinical practice
Screen for periodontitis and smoking, as these factors increase the risk of early implant loss
Consider using implants >10 mm in length if clinically appropriate
Be aware that implant design, such as rough collar surfaces, may contribute to higher risks of both early and late implant loss
Implant dentistry treatment outcomes have typically been evaluated in small, highly selected patient groups, potentially leading to conclusions that are not applicable to the general population. A group of experts from Gothenburg, Sweden, addressed the need for a more representative study by reviewing more than 2,700 patient files from the Swedish national registry to assess the effectiveness of implant therapy.
Their findings indicate that implant loss is not uncommon, with 4.4% of patients experiencing early and 2.0% experiencing late implant loss. Smoking, a diagnosis of periodontitis, implant length <10 mm, and implant type/characteristics (referred to as implant brands in the publication) were found to influence implant outcomes. As most information on implant outcomes comes from “convenience patient samples”, this study provides valuable insight from a real-world cohort.
Dr. med. dent. Karin Wolleb Torrisi
This study represents long-term implant results in a real population, of both patients and practitioners! It is based on a register covering various clinics and private practices, so has no bias due to special patient selection.
The authors analyzed the patient files of 2,765 patients in Sweden who had received implant-supported restorative therapy in 2003, a mean of 5 years previously. Nearly 600 of these patients then attended a clinical examination to assess for implant loss, at a mean of 8.9 years since implant placement.
When analyzing the patient files, the authors found that 121/2,765 patients (4.4%) had experienced early implant loss, meaning it occurred prior to supraconstruction connection. This corresponded to a loss of 154 implants (1.4%). Of the 596 patients who were examined, 45 (7.6%) experienced early or late implant loss, of a total of 72 implants (3.0%). Late implant loss was experienced by 25/596 patients (4.3%), of 46 implants (2.0%).
The authors then investigated patient and implant characteristics that were associated with early and/or late implant loss. An initial diagnosis of periodontitis, smoking, implants <10 mm in length, and implant type/characteristics (referred to as implant brand in the original publication) were significantly associated with early implant loss (all P<0.05). For late implant loss, the implant implant type/characteristics were a significant factor.
In this study, soft tissue level implants (brand S) – characterized by a machined (smooth) supraosseous implant collar and an intraosseous sandblasted and acid-etched surface – demonstrated much lower odds of both late and early loss compared to implants with rough or porous collar surfaces (e.g., anodized) (brands NB and AT). Specifically:
For late loss, rough collar implants (NB and AT) had an OR of 2.1 and 1.9 versus 1 for soft tissue level implants.
For early loss, rough collar implants had an OR of 6.1 and 6.2 versus 1 for soft tissue level implants.
However, the authors noted that no definitive conclusions about implant design can be drawn from this study, and further investigations are needed to confirm these findings.
The association between periodontitis and early implant loss may be due to the consequences of disease progression, which can lead to tooth loss and an edentulous ridge with reduced dimensions; these reduced dimensions may also explain the finding related to implant length <10 mm. Further work would be needed to explain the significance of the implant type/characteristics for early and late loss.
While much information on implant outcomes is sourced from small, specific patient groups, this study provides valuable insights from a large, randomly selected real-world population. The findings that patient- and implant-related characteristics can influence outcome across treatment settings and clinician training could be considered relevant for all patients undergoing implant-supported restorative therapy.
