Techniques to improve the accuracy of complete arch implant intraoral digital scans: A systematic review.

STATEMENT OF PROBLEM: The best method of optimizing the accuracy of complete arch intraoral digital scans is still unclear. For instance, the location of the scan bodies can be significantly distorted with respect to their actual positions, which would lead to a nonpassive fit of the definitive prosthesis. PURPOSE: The purpose of this systematic review was to analyze available techniques for improving the accuracy of digital scans in implant-supported complete arch fixed prostheses. MATERIAL AND METHODS: Three databases (Medline, Embase, and Google Scholar) were searched, and the results obtained were supplemented by a hand search. Specific descriptors identified techniques whose objective were to increase the accuracy of digital scans in implant-supported complete arch fixed prostheses. Titles and abstracts were screened by 2 independent reviewers, and unclear results were discussed with a third independent reviewer. A qualitative analysis based on procedural parameters was used. The interexaminer agreements of both were assessed by the Cohen kappa statistic, and the Risk of Bias Tool was used to assess the risk of bias across the studies. RESULTS: A total of 17 techniques matching the inclusion criteria were evaluated. Higher accuracy but also differences regarding the need for supplementary devices, number of intraoral scans, and time consumption of clinical and software program steps were observed compared with the conventional digital scanning protocol. The use of a splinting device was common to most of the studies. The outcome variables for the evaluation of the effectiveness of these protocols were heterogeneous. CONCLUSIONS: The use of additional techniques during intraoral scanning can improve accuracy in implant-supported complete arch fixed prostheses. However, higher complexity for those procedures should be expected.

Polyetheretherketone in Implant Prosthodontics: A Scoping Review.

PURPOSE: To undertake a scoping review of the available research on the application of polyetheretherketone (PEEK) in implant prosthodontics, map the available literature in order to highlight possible gaps in knowledge and, if possible, extract clinical guidelines. MATERIALS AND METHODS: The literature on PEEK in implant prosthodontics published through August 2018 was identified with an online search of MEDLINE (via PubMed), Science Direct, Embase (via Ovid), and Google Scholar databases. Qualitative and quantitative syntheses were carried out for original research studies. RESULTS: The amount of published original research studies was found to be limited. PEEK was found to be applied as a material in the fabrication of implant-supported fixed dental prosthesis (IFDP) frameworks (43%), prosthetic implant abutments (35%), implant abutment screws (15%), and retention clips on implant bars (7%). Only 38% of the studies were clinical studies, while 15% were observational and 47% were in vitro. The studies identified did not permit the estimation of long-term survival nor success rates for any of the prosthetic components. The results only allowed a preliminary short-term assessment of PEEK IFDP frameworks, which presented satisfactory survival but alarming success rates over the first year of service. CONCLUSION: In light of the paucity of evidence on the viability of PEEK as an implant-prosthodontic material, its use cannot yet be endorsed. Clinicians should heed the suggested protocols to improve mechanical performance and lower the incidence of prosthetic complications. Further high-quality research is needed for an enhanced understanding of the material's viability.