Why Doesn't the Scanner Scan Well on Very Glossy Crowns or Very White Composite/Resin?
Intraoral scanners collect surface data by analyzing light reflection. When a surface is very glossy or very white and translucent (like some crowns or bright resins and composites), too much light reflects back (overexposure), and the software makes errors matching reference points on the surface. This causes a drop in scan quality or an incomplete scan. This problem is similar to something already well known to happen with metal crowns.
Another point is that some newer scanners have an AI layer that calculates a confidence score for each scanned point and uses it to weight and stitch the data. On unusual surfaces (very glossy, very white, without a defined texture), this algorithm sometimes assigns the wrong score and down-weights or discards exactly the points that are harder to scan, which results in an incomplete or noisy scan.
Practical solution: turning off the scanner's smart processing (AI mode) improves the result in many cases. That's because in this mode, instead of relying on the trained model, the scanner works directly on the raw data, which is usually more accurate for these particular surfaces.
Note: the exact cause of this phenomenon hasn't yet been fully and formally documented in the scientific literature, and turning off AI is more of an experience-based workaround known among users, not an official standard from manufacturers.