All of the Following Are Verified Health-Related Issues or Outcomes

All of the following are verified health-related issues or outcomes associated with mechanized instrumentation except which one?

A) Interproximal areas,furcations,the cementoenamel junction,and multirooted teeth will most likely exhibit residual calculus regardless of instrument method.
B) Bleeding on probing and probing depths are both reduced to equivalent levels when sonic and ultrasonic methods are compared with each other and with manual scaling.
C) The best results from nonsurgical periodontal therapy occur with the use of mechanized instrumentation versus manual instrumentation or a combination of both.
D) Longitudinal studies are needed to evaluate clinical parameters such as clinical attachment levels after mechanized instrumentation.