Is it true that Mentor implants have a higher tendency to cause rippling compared to Motiva? And difference between high vs mod?

A lot goes in to what makes an implant ripple or not, and "the most important issue is your tissue" as I always tell my patients. A small amount of fat and breast tissue covering the implant, or a very thin fine skin type, or not going under the muscle are all the main contributors to visible implant rippling.

The next important issue is the development of a contacted capsule, which can cause rippling in many implant to become visible.

When it comes to implants, smooth vs textured and saline vs gel are the only comparisons I would be willing to make after 20 years of using many types and many brands of implants.

Rather than focus on implant, focus on your surgeons explanation on your risk for rippling, and especially how he or she will avoid visible rippling.