The endodontist who built the software he could not find anywhere else.
Dr. Gary Carr founded TDO in 1998 not because he wanted to build software, but because no existing software reflected how an endodontic practice actually works.
The story of TDO does not begin with software. It begins with an endodontist who could not accept a 50 percent failure rate and a scanning electron microscope installed in a garage.
Dr. Gary Carr's path to endodontics was not conventional. He served in the United States Navy as an electronics technician before entering dental school. That technical background - the habit of taking things apart, understanding how systems work, and rebuilding them better - shaped everything that followed. Before finishing his endodontic residency, he had already purchased a scanning electron microscope and installed it in his garage.
Working with Drs. John Frank and Franklin Weine, Carr undertook a study of endodontic surgical failure using fresh human cadavers and the SEM. The study identified four specific errors responsible for the majority of surgical failures: failure to locate the root apex, failure to seal the root end, failure to identify and treat anatomical variations, and damage to the root surface during resection.
The findings made one thing clear: endodontic surgery required dramatically better visualization. The standard of care at the time was 2.5x to 4.5x loupes. Carr determined that a minimum of 6x magnification was necessary for predictable microsurgery and introduced the surgical operating microscope to endodontics - a tool already standard in neurosurgery, micro-vascular surgery, and ENT.
At the same time, he developed a system of ultrasonic root end preparation that replaced the traditional bur technique. The combination of the microscope and ultrasonic preparation was not two separate innovations. They were inseparable. The microscope made it possible to see the root end anatomy in detail. The ultrasonic tips made it possible to prepare that anatomy without destroying it. One without the other was incomplete.
Excellence does not come easy, and humans are surprisingly resistant to change even when all evidence points to the need for it.
Dr. Gary Carr
In 1991, Dr. Carr founded the Pacific Endodontic Research Foundation and began running monthly hands-on training courses in microscopic endodontics. Over the next 10 years, those courses trained more than 700 endodontists in the technique. The resistance was significant. The adoption was slow. But the clinical evidence was overwhelming, and the practitioners who trained at PERF became advocates within their own communities.
In 1992, Carr was invited to author the microsurgery chapter in Pathways of the Pulp, the definitive endodontic textbook. The chapter established the academic foundation for what PERF was teaching clinically.
By 1995, Carr had begun teaching program directors directly, bringing the microscope into postgraduate education. The American Association of Endodontists eventually made microscope training a requirement for accredited residency programs. The technique that had been dismissed as unnecessary became the standard. That pattern - seeing where the evidence pointed before others were ready to follow - is the same pattern that produced TDO Software.
In the late 1990s, Dr. Carr and his office manager Amy Taylor began building the software his practice needed and could not find.
The goal was not to produce another practice management product. It was to build a truly integrated digital office that would simplify and unify every function within an endodontic practice. At the same time, they hoped to create a disciplined way of collecting data that would allow for scientific analysis of endodontic outcomes and standardized evidence-based protocols.
Version 1.01 entered beta testing in 1998, tested by 30 dedicated endodontic specialists drawn from prior PERF faculty members. These were clinicians who had already shown they were willing to challenge the status quo. After two years of extensive testing and refinement of the ergonomic concepts first developed at PERF, TDO Software launched commercially in early 2000.
The software reflected something that no general dental product had ever been designed around: the specific workflow, clinical depth, and data requirements of an endodontic specialty practice. Every form, every field, every report was built around how an endodontist actually works.
Dr. Carr now serves as an advisor to TDO. He continues his research at the Pacific Endodontic Research Foundation and hosts postgraduate residents at his lab.
TDO was acquired by Valsoft in 2024. Valsoft is a vertical market software holding company based in Montreal that acquires and grows specialized software businesses for the long term. The acquisition has not changed what TDO does or who it serves.
TDOS, the cloud-native evolution of the original platform, represents the most significant update to TDO in its history. It brings the same clinical depth that Dr. Carr built into the original software to any device, from any location, without a server. The software he built for his own operatory in 1998 is now accessible from anywhere in the world.
Dr. Carr continues active research at PERF and hosts postgraduate residents for visits to his lab. His involvement in training the next generation of endodontists is not honorary. It is active.
Learn about TDO Postgrads
THE PLATFORM HE BUILTSee what 25+ years of endodontic focus looks like.
TDO was built by an endodontist for endodontists. That origin is visible in every clinical form, every workflow, and every report.