Mitigating thermal risk in guided implant surgery: Hollow-guide and alternative designs

The generation of heat during osteotomy preparation is a significant risk factor for thermal osteonecrosis, which may lead to implant failure. While static surgical guides enhance placement accuracy, they can physically obstruct the flow of external coolant, paradoxically increasing the risk for thermal injury.

(1) Review of thermal necrosis and critical temperatures during osteotomy preparation. Advantages and disadvantages of static guided surgery. (2) Design and fabrication of static surgical guides with direct coolant channels to the osteotomy site. Variations include: Hollow-Guide, internal irrigation channels, external irrigation channels, and mesh-based guide fabrication.

A new, simplified workflow is proposed to design and fabricate surgical guides for implant placement with the delivery of coolant directly to the osteotomy site with no obstruction and decreased risk of thermal injury and implant failure.

This report details a novel approach to mitigating thermal injury during guided dental implant surgery. The application of a patient-specific, three-dimensional-printed surgical guide featuring an integrated Hollow-Guide design bypasses conventional coolant obstruction by delivering sterile saline directly to the osteotomy site via segmentation and selective hollowing. A simple workflow is described to integrate multidirectional irrigation to the surgical site and reduce the risk of thermal injury, subsequent osteonecrosis, and implant failure. While traditional static guides serve as a passive positioning jig, the Hollow-Guide acts as an active therapeutic device during implant preparation and placement.

Static surgical guides significantly improve implant placement accuracy, but impede traditional delivery methods of irrigation and coolants to the surgical site. Maintenance of bone temperatures below a critical threshold is necessary to prevent thermal necrosis and implant failure. A digital workflow has been proposed to allow for irrigation directly at the osteotomy site without the need for complex internal or external irrigation channels.

Preparing the jawbone for dental implants generates significant heat from drilling. If the bone gets too hot, the tissue can die, ultimately leading to failure and loss of the implant. Dentists often use three-dimensional-printed surgical guides to ensure implants are placed in the correct anatomical position, but these templates can physically block external irrigation from reaching the drill site, increasing the risk of thermal damage. This article introduces a new design technique called the "Hollow-Guide." This method modifies the surgical guide to include built-in channels that allow sterile water or saline to flow directly to the bone during drilling. By solving the problem of blocked water flow, this new design helps keep the bone cool while maintaining the high accuracy of guided surgery. This simple workflow transforms the guide from a passive positioning tool into an active safety device that helps prevent bone damage and ensures better long-term success for dental implants.