Methodological approaches in graded dental ceramics: a scoping review protocol.

Objectives: This review will map the various methodological approaches used in graded dental ceramics and distinguish their material characteristics and properties. The aim is to identify gaps in the development and application of grading in dental ceramic systems.

Introduction: The advantage of functionally graded materials is the absence of the weakest link, with no distinct boundaries, thereby eliminating the possibility of stress concentrations at the interfaces. Functionally graded materials are well established in nature, such as in human teeth, bone, and the bio-tissues of plants and animals. This concept has also been explored in dental ceramics to enhance fatigue resistance and strength.

Inclusion criteria: This review will include observational studies and interventional studies, such as in vitro and experimental studies, on functionally graded dental ceramic systems. Studies that use finite element analysis to evaluate stress distributions, and studies on the mechanical performance of graded dental ceramics, irrespective of the type of ceramic material, design, or thickness of graded layers, will be considered.

Method: The review will follow the JBI methodology for scoping reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. MEDLINE (PubMed), Scopus, ProQuest Dissertations and Theses (EBSCOhost), Cochrane CENTRAL, and Google Scholar will be searched for English language studies. The search strategy will be based on MeSH terms and free-text specific terms, and will be adapted for each database. Two independent reviewers will screen titles and abstracts, and extract data from selected sources. The data extracted from the selected studies will be analyzed and presented in the form of tables and figures.

Review registration: Open Science Framework: https://osf.io/ahsp7.