Finite element analysis of the stress distribution in posterior zirconia implants: a systematic review

OBJECTIVES: The aim of this systematic review was to assess the stress distribution of zirconia implants compared to titanium implants using finite element analysis (FEA). The main research question was whether zirconia demonstrate mechanical behavior comparable to or better than titanium in posterior applications. MATERIALS AND METHODS: This study was previously registered in PROSPERO (CRD42023480344). Six electronic databases (Web of Science, PubMed, Scopus, Capes Journals, Lilacs, and Scielo) were searched up to March 2024. The terms "finite element analysis," "posterior*," "jaw," and "zirconia implant" were used. The inclusion criteria were in silico finite element studies comparing zirconia and titanium implants in the posterior jaws, exclusion criteria were non-English, non-finite element, anterior region, or studies without zirconia-only groups. Five evaluators independently conducted assessments using predefined criteria in Rayyan©. The risk of bias was assessed by ROBFEAD. Titles and abstracts were screened, and studies meeting the criteria underwent full-text assessment. RESULTS: The search retrieved 512 studies, with 368 remaining after duplicate removal. Seven studies met the inclusion criteria, its reference lists were also screened. Zirconia implants showed mechanical strength equal to or greater than titanium implants. Implant geometry and abutment diameter influenced stress distribution on the peri-implant bone, implant, and abutment. Bioglass-zirconia implants demonstrated superior performance compared to conventional zirconia. Root-like implant geometries and thread designs were advantageous in posterior regions. A limitation of finite element studies is the variability in evaluation criteria, modeling parameters, material properties, loading conditions, and group configurations, as well as simplifications in geometry and boundary conditions, which may impact the comparability and clinical relevance of the results. CONCLUSIONS: Zirconia implants offer potential for stress modulation and are viable in posterior areas. However, properties vary based on geometry, thread, and abutment design compared to titanium. CLINICAL RELEVANCE: Understanding the biomechanical behavior of zirconia implants can improve clinical outcomes in dental implantology, emphasizing the need for further research. This review received no external funding.