The aim of this study is to present the clinical data from the use of implants that were placed and restored in four independent private dental offices. In part I, the survival rate was calculated and the failure causes were associated with some potential risk factors. In part II, the surgical and prosthetic complications were also recorded and associated both with failures and clinical factors. During 1990–2002 (mean observation 4.6 years), 1692 dental implants were placed and restored in 405 patients in 4 private clinics following the same treatment protocol. The prosthetic restorations included fixed partial dentures, single crowns, and overdentures. The results were statistically analyzed and survival rate probability curves were calculated according to Kaplan-Meier analysis. Part I: Seventy-four implants (4.4%) in a total of 1692 implants failed. The mean of time elapsed before removal of the failed implants was 40 months. The failure rate was higher in the maxilla in patients with metabolic diseases, in D4 bone quality, in smokers, and in patients with insufficient oral hygiene. Part II: Surgical complications happened to 65 implants (3.8%). Prosthetic complications appeared in 152 implants (9%). The overall survival rate (95.6%) in a period of 1 to 12 years is comparable to other studies. The early failures represented a high percentage of failures. Peri-implantitis was the main cause of late failures. The results of this study indicate that the use of implants in private clinics is a safe and predictable method for the treatment of partially or completely edentulous patients, if the proper clinical protocol is followed. The need of a severe recall program must also be emphasized.

Objective: The aim of this systematic review was to evaluate the influence of the characteristics of intraoral scan bodies (ISBs) on the accuracy of intraoral scanning.Materials and Methods: An electronic search was conducted through PubMed (MEDLINE), Scopus and Cochrane Library, up to March 2023. The literature search intended to retrieve all relevant clinical and in vitro studies about the effect that the various properties of ISBs may have on the accuracy (trueness and precision) of intraoral scanning. Only publications in English language were selected with animal studies, case reports, case series, technique presentation articles and expert opinions being excluded.Results: A total of 28 studies met the inclusion criteria and were included in this systematic review. They were published between 2019 and 2023 and were all in vitro studies. Among the parameters described, the scan body material, position, geometry, height, diameter, and fixation torque were evaluated. The most common materials used for ISBs were polyetheretherketone (PEEK) and titanium alloys. The diameter and position of ISBs seemed to affect the trueness of implant impressions. Subgingival implant position and decreased ISB height affected negatively the trueness of scanning. Geometrical characteristics of ISBs also affect the implant impression accuracy, especially the bevel location and the types of designing modifications.Conclusions: The characteristics of the currently used ISBs vary widely and the available scientific evidence is not yet conclusive about the optimal design of ISB. The implant impression accuracy achieved by any of the studied parameters is encouraging. Clinical studies are however necessary for more concrete conclusions.Clinical Significance: ISBs play a vital role in the digital workflow and influence significantly the accuracy and fit of implant restorations. More clinical trials are needed in order to conclude to the optimal characteristics of ISBs which would further enhance the success of the restorations.