Which of the following provides the highest level of evidence for treatment questions? 

All of the following are recommened during air polishing to increase safety of the procedure except:

With appropriate technique, endotoxin is easily removed with ultrasonic technology. Endotoxin is firmly imbedded into cementum. 

A patient with anunshielded cardiac pacemaker requires antibiotic premedication before treatment.  Ultrasonic scaling systems are safe in patients with an unshielded cardiac pacemaker.  

Plaque control instruction (OHI) should be initiated before the oral prophylaxis is started because the:

For a sickle scaler or universal curet, the internal angle formed by the junction of the instrument face and the lateral surface is between 70o  and 80o.  For an area-specific curet, the internal angle formed by the junction of the instrument face and the lateral surface also is between 70o and 80o.

The curved left and right ultrasonic inserts are designed to: 1. adjust to convex root anatomy 2. adapt to concave root anatomy 3. adapt the back and lateral sides of the insert to the root surface 4. adapt only the lateral side of the insert to the root surface. 

Caries management by risk assessment (CAMBRA) is an evidence based approach to the prevention and management of caries, which assesses levels of risk and serves as a guidlines for interventions.  Current research indicates that the most important factor in dental caries prevention and treatment is to modify and correct the dental biofilm and transform oral factors to favor dental health. 

The appropriate mechanism of action for a piezoelectric device is: 

During preparation of the magnetostrictive ultrasonic for use, which of the following steps would be ompleted first?