Currently, the process of fitting a dental crown involves multiple steps spread over several appointments. Initially, dentists must meticulously remove decayed material, prepare the tooth structure, capture dental impressions, and fit a provisional crown. The final, permanent crown is fabricated externally using the impression and later installed in a subsequent visit. MIR seeks to condense and enhance this protocol by enabling precise tooth preparation following a comprehensive digital plan, thereby expediting the entire treatment cycle.

The compact scale of the MIR robot is an engineering feat in itself, measuring approximately 43 by 26 by 28 millimeters—comparable in size to a wine cork. Such dimensions ensure the device can comfortably operate within the confines of an open human mouth. Unlike fully autonomous units, MIR’s motors and control systems reside outside the oral cavity, connected via flexible drive shafts, cables, and tubes. This unique design addresses spatial constraints while maintaining operational efficacy, as highlighted by Dr. Yukiko Tomooka, the first author on the key publication describing its development.

A key feature distinguishing the MIR robot is its integration with digital dentistry workflows. Following an initial intraoral scan during the patient’s first visit, detailed treatment planning allows for precise mapping of the areas requiring material removal. Subsequently, a bespoke dental splint is fabricated to securely anchor the robot to the patient’s teeth, ensuring that MIR moves synchronously with natural head movements—an essential consideration for maintaining preparation accuracy in a dynamic environment.

Laboratory assessments have provided promising data on MIR’s performance. The device employs a two-step drilling approach: initially, a broad drill shapes the occlusal (top) surface by reducing excess tooth material; subsequently, a slender, elongated drill meticulously contours the lateral aspects of the tooth. This method mirrors the tactile and procedural nuances employed by skilled dentists but executed under robotic precision. Despite the prototype’s current lack of integrated positional sensors, its positional deviation remains impressively below 0.2 millimeters, suggesting that sensory augmentation could further refine its accuracy.

Force measurements during the robotic drilling process serve as a testament to its patient-friendly mechanics. The system exerts forces under five newtons—comparable to the gentle weight of a half-liter water bottle. Maintaining low applied forces is critical for patient comfort and safety, minimizing risks such as excessive tooth stress or inadvertent damage to surrounding tissues. Additionally, preliminary acoustic analyses are underway to evaluate whether the noise generated by the device remains within acceptable limits for dental practice environments.

Looking ahead, the research team is focused on embedding sensors and a miniature camera within the MIR framework. These enhancements aim to enable real-time feedback on the robot’s position and monitor treatment progression, crucial for dynamic adjustments during procedures. An important resilience feature will be the robot’s ability to retain its positional awareness even after unexpected interruptions, like power outages, ensuring seamless continuation of treatment without compromising outcomes or patient safety, all while preserving the device’s diminutive size.

The collaboration underpinning MIR’s development is notably interdisciplinary and translational. The project benefits from close cooperation between engineers, clinicians, and industry partners, including the Center for Dentistry at the University of Zurich, Camlog Biotechnologies GmbH based in Basel, and the University of Bern. Funding support provided by Switzerland’s innovation agency Innosuisse underscores the project’s potential to contribute significantly to both the scientific community and commercial clinical dental practice.

MIR exemplifies the broader trend in medical robotics towards minimally invasive, precision-guided technologies that enhance therapeutic delivery while reducing patient burden. By automating a labor-intensive manual procedure, the robot not only promises to improve clinical precision and reproducibility but also to transform patient workflows, potentially minimizing chair time and discomfort. Such innovations have the capacity to make dental care more accessible, efficient, and patient-friendly.

The ongoing research into integrating sensory modalities and optimizing user interfaces aims to prepare MIR for the rigors of clinical validation and eventual regulatory approval. As the device evolves, attention will also be given to sterilization protocols and ergonomic deployment within diverse dental practice settings. Through iterative development informed by clinical feedback, MIR aspires to set new standards for robotic dental interventions.

This pioneering effort stands as a vivid illustration of how robotics and artificial intelligence can be harnessed to address practical challenges in healthcare. MIR’s precise, controlled execution of complex dental tasks offers a glimpse into future possibilities where automated systems enhance human expertise, improving outcomes and patient satisfaction simultaneously. The successful translation of such technologies from laboratory prototypes to everyday clinical instruments will mark a significant milestone in dental medicine’s evolution.

The University of Basel’s miniaturized dental robot not only makes waves in the field of dental robotics but also exemplifies the potential for micro-scale engineering solutions in medicine. Through meticulous design, innovative engineering, and cross-disciplinary collaboration, the MIR platform is positioned to eventually transform routine dental treatments into streamlined, highly precise procedures, ultimately benefiting clinicians and patients alike.

Subject of Research: Development and evaluation of a miniature intraoral robot for automated dental crown preparation.

Article Title: Miniature Intraoral Robot for Precise Automated Tooth Preparation in Dental Crown Treatment.

News Publication Date: Not explicitly provided; implied recent (circa 2024).

Web References: DOI: 10.1109/TMRB.2026.3682629

References: Publication in IEEE Transactions on Medical Robotics and Bionics.

Image Credits: University of Basel, Catherine Weyer

Keywords: dental robotics, intraoral robot, tooth preparation, crown treatment, medical robotics, biomedical engineering, precision dentistry, automated dental devices, miniature robots, dental innovation

A pioneering study conducted by researchers at The Fourth Military Medical University in China offers vital insights into how print angle and layer thickness, two fundamental 3D printing parameters, influence the dimensional fidelity and adaptation of resin-based ceramic crowns fabricated via digital light processing (DLP). The team’s meticulous approach involved designing a mandibular first molar crown and systematically printing it at nine distinct angles, spanning from 90° to 270°, coupled with two different layer thicknesses of 50 and 100 micrometers. This methodical variation allowed for a comprehensive assessment of the resultant crowns against their digital blueprints and prepared tooth models.

Measurement of crown trueness—the degree to which the printed crown conforms to its intended digital model—was central to the study. Employing advanced metrological techniques, the researchers found that crowns fabricated at moderate print angles between 150° and 180° demonstrated superior accuracy and optimal internal fit when produced with a 50-μm layer thickness. Conversely, crowns printed with a thicker 100-μm layer displayed a more concentrated distribution of deviations, indicating higher repeatability across multiple prints albeit with slightly reduced absolute accuracy. Such findings highlight a critical trade-off between fine detail resolution and manufacturing reproducibility in dental 3D printing.

Delving deeper, the study revealed notable spatial heterogeneity in dimensional deviations across the inner surfaces of the crowns. Marginal areas, critical for preventing microleakage, exhibited inward shrinkage tendencies, likely attributable to resin polymerization stresses and light curing gradients inherent to DLP technology. In contrast, occlusal surfaces displayed outward bulging, a phenomenon that could be attributed to layer stacking and resin flow dynamics. These nuanced deformation patterns illuminate why crowns that appear acceptable in gross morphology may require intraoral adjustments to achieve snug seating during clinical application.

Understanding these spatial variation trends has profound clinical implications, as maladaptation in marginal zones can precipitate plaque accumulation and secondary pathology. By identifying that moderate print angles promote uniform accuracy and that thinner layers enhance internal fit, the research provides a foundation for standardized printing protocols. This standardization could reduce chairside adjustment times and improve the longevity of restorations by ensuring consistent marginal seal and occlusal conformity.

Furthermore, the study underscores the balancing act between accuracy and repeatability. While 50-μm layers yield crowns with the highest trueness, the slightly less precise yet more reproducible 100-μm layers may be preferred when batch consistency is prioritized over the finest detail, such as in mass production scenarios. This trade-off is particularly relevant for dental laboratories and clinics seeking scalable solutions without compromising clinical acceptability.

The implications extend beyond mere parameter tuning, contributing to the broader understanding of resin-based ceramic behavior under photopolymerization conditions unique to DLP printing. The complex interplay between light exposure angle, layer thickness, and resin chemistry orchestrates the microstructural evolution of the crown, dictating its final dimensional stability and mechanical properties. These findings invite further exploration into resin formulations and adaptive curing strategies to mitigate deformation while preserving throughput.

Clinicians and dental technicians armed with this knowledge can tailor their 3D printing workflows to harness the benefits of digital dentistry more fully. Optimizing print orientation and layer resolution not only elevates restoration quality but also streamlines post-processing steps, reducing costly remakes and enhancing patient experience. In essence, the study bridges the gap between emerging manufacturing technologies and clinical excellence, paving the way for widespread adoption of resin-based ceramic crowns in routine dental care.

Looking ahead, ongoing research into print parameter optimization promises to refine multi-material and functionally graded restorations, integrating esthetics and biomechanics seamlessly. As materials science intersects with additive manufacturing, next-generation dental prosthetics will likely surpass current limitations in fit, durability, and customization, revolutionizing restorative dentistry.

This research marks a significant leap in digital prosthodontics, advocating print angles between 150° and 180° coupled with 50-μm layer thickness as the optimal approach for balancing accuracy and clinical fit in resin-based ceramic crowns. Such parameters harness the precision potential of DLP 3D printing while addressing the inherent material and process challenges, ultimately supporting superior patient outcomes through advanced digital workflows.

Subject of Research: Not applicable

Article Title: Effect of print parameters on the accuracy and fit of 3D-printed resin-based ceramic crowns

References: DOI 10.1016/j.dtrs.2025.100004

Image Credits: Shizhu Bai

Keywords

Chemical engineering, Polymer chemistry, Health and medicine, Dentistry, Prosthetics