An umbrella term with three levels
Computer-assisted implantology and 'guided surgery' are frequently used synonymously in everyday dental practice. The dentist and oral surgeon Dr Roman d'Olive, who runs two practices in Mulhouse in France and in Neuenburg am Rhein in Baden, considers this equation imprecise. On the podcast Queens & Sons of Dentistry, where he reports in a three-part series on his path into computer-assisted implantology, he explains why he does not primarily see himself as a specialist in guide-supported surgery, but prefers to speak more broadly of computer-assisted navigation. For a clean distinction he refers to a publication by the ITI in which the procedures are systematically differentiated. According to this, guided surgery is divided into three chapters: static guidance by means of a surgical guide, dynamic navigation by means of a camera system, and robotics.
Level one: the static surgical guide
The static variant works with a pre-fabricated surgical guide that forces the drilling into the planned position via guide sleeves. Dr d'Olive assigns it a clear strategic role. In his German practice, in which several practitioners will be working in future, a pilot drilling with a static guide is to be carried out for every patient, so that all practitioners reach the same standard. For a practice that predominantly places single implants, the purchase of an elaborate navigation device may under some circumstances not be worthwhile at all. At the same time he names a weakness of the guide: because the work is carried out through the guide sleeves, tactile feedback is lost, and the bone can be felt considerably less during the drilling. Particularly in immediate implant placement and in augmented bone, however, he considers the feedback from the tissue to be decisive, for instance in order to adapt the drilling sequence depending on whether the bone is hard or bleeds heavily.
Level two: dynamic navigation – 'freehand, but under control'
The second level is dynamic navigation, in which the practitioner is guided with computer support in real time during the drilling. By his own account, this form fascinates Dr d'Olive the most, because it combines the merits of both worlds. The operator effectively works freehand, feels bone and tissue and can assess how much primary stability the implant will achieve – relevant, for example, for immediate loading and immediate restoration. At the same time the implant position remains exactly where it was planned, without deviation to the right or left. In the conversation the comparison is drawn with a driver assistance system or a GPS: the steering wheel stays in the driver's hand, yet the direction is safeguarded. On accuracy, d'Olive refers to the literature, according to which navigated work is just as precise as the static guide. A genuine change, however, is the way of working: the camera hangs above the practitioner's head, the line of sight between the camera and the markers on the instruments must not be obscured, and during the drilling the gaze goes to the screen instead of into the mouth – on the podcast this is compared to driving a car while constantly looking at the navigation device instead of at the road.
Level three: robotics
The third level is robotics – for Dr d'Olive the future of the discipline, and not a distant one: he believes it will not be long in coming. At a congress in Bangkok he met Chinese professors in whose practices several thousand implants have already been inserted with robotic support. He describes two forms: in the fully automated system a pedal triggers the drilling and a robotic arm places the implant, with a human being scarcely involved any more – a scenario he classifies as 'a bit spooky' for Europeans. The second variant is semi-automated: the robotic arm is connected to the contra-angle handpiece and prevents incorrect drilling like a safety stop – too deep, too far to the right or left is simply not possible. D'Olive describes the principle as a static guide without a guide. A US company is said to be very far ahead in this field already.
The levels as a practice strategy
Asked whether the levels are climbed one after another, d'Olive answers with a strategic view: which level makes sense depends on the case spectrum and on the structure of the practice in question. In his own practice the decision was made long ago – not a single full-arch case is still operated on there without navigation, and navigated in preference to a static guide. At the same time he emphasises that freehand competence remains the foundation: if the system no longer matches reality or the computer crashes, the operator must be in a position to remove the camera and continue working freely.