Enhancing Intraoral Scanning Accuracy: From the Influencing Factors to a Procedural Guideline

Background/Objectives: Intraoral scanning, a fast-evolving technology, is increasingly integrated into actual dental workflows due to its numerous advantages. Despite its growing adoption, challenges related to the accuracy of digital impressions remain. The existing literature identifies most of the factors influencing intraoral scanning accuracy (defined by precision and trueness), but it is fragmented and lacks a unified synthesis. In response to this gap, the present study aims to consolidate and structure the current evidence on the determinant factors and, based on these findings, to develop a clinically applicable procedural guideline for dental practitioners. Methods: A comprehensive literature review identified 43 distinct factors influencing intraoral scanning. Results: These factors encompass variables such as software versions and updates, implant characteristics (e.g., position, angulation, scan body design), materials, environmental conditions (e.g., lighting), and procedural elements including scanning strategy, pattern, aids, and operator experience. Subsequently, these identified factors were systematically classified into five distinct groups based on inherent similarities and relevance within the scanning workflow: IOS—characteristics and maintenance, intraoral morphology, materials, ambient conditions, and scanning strategy. To translate these findings into a practical framework, a four-step protocol was developed, designed for straightforward application by researchers and clinicians. Conclusions: This protocol—comprising: (1) Maintenance, (2) Evaluation, (3) Establishment and Execution of Scanning Strategy, and (4) Verification—aims to guide users effectively through the intraoral scanning process, mitigate common clinical challenges, and ensure broad applicability across diverse scanner systems, irrespective of the manufacturer or model.