The Instrument PSL and Instrument PSR were a delight to work with. I removed calculus from furcations and from distal of upper molars that I had previously left behind. I didn't need to twist into uncomfortable positions in order to get good access, which meant less stretching and pulling of the patients tissues and less strain on my wrists and my neck. Because access was easier, it felt less invasive for the patient which complimented my minimally invasive approach.