Digital workflow development of pin-reinforced indirect zirconia posterior restorations

Introduction

Digital dentistry is continuing to have a profound impact on the delivery of clinical care for patients and clinicians by providing improved efficiency and accuracy and a streamlined workflow. This preliminary investigation explored the use of the Stabilok Dentinal Pin System for pin-reinforced onlay preparation and assessment of an indirect zirconia posterior restoration using novel digital dentistry technologies.

Methods and Materials

A pinlay was prepared on a dentiform molar tooth. The Stabilok Dentinal Pin System was employed, and grade 1 titanium, 0.6 mm diameter dentin pins were placed. Thermography was employed to assess surface temperature of the drill and pin. Shade was determined using a digital shade assessment software. The pinlay preparation was scanned and optimized (Medit scanner and Medit Link software) and emailed to a commercial laboratory for the design and fabrication of a zirconia pinlay restoration. Using 3Shape, a four-surface pin reinforced restoration was designed and milled with a multi-colored, multi-yttria zirconia (46% translucency; flexural strength of 1025 MPa).

Results

The pinlay restoration was seated on the prepared tooth without any fit issues. The restoration was deemed clinically acceptable. The surface temperature of the twist drill and pin were recorded as 20.16 and 21.17 degrees Celsius, respectively. The zirconia pinlay restoration shade was digitally assessed as 100% A1 (Vita).

Conclusion

Although it is a very limited study on a single typodont, this simulated preliminary investigation illustrated that pin-reinforced indirect posterior restoration using digital dentistry is an approach that is simple, efficient and accurate. The workflow resulted in a clinically acceptable zirconia restoration with minimal surface temperature change (< 5-degree increase compared to adjacent typodonts) during drilling and pin placement. Consideration of alternative restorative workflows, including both traditional and modified indirect techniques, remains essential to support accessible, patient‑centered care while promoting sustainable and adaptable clinical workflows.