Bearing failure. The turbine bearings inside a high-speed handpiece wear down from heat, speed, and repeated sterilization cycles. Most handpieces give 2 or 3 warning signs, noise, vibration, warmth, before failure is complete. Catching it at the noise or slow-cutting stage usually means a bearing replacement starting at $99.95. Waiting until the handpiece stops often means a turbine replacement at $189 or more.