Roughness and loss of substance of tooth surfaces after biofilm removal

Materials and methods
Post extraction, impacted 3rd molars were marked and stored teeth were then divided and subjected to the following treatments:

• 1A – Airflow EMS PLUS powder at 2mm distance for 5 sec with a pressure of 1.8 bar at an angle of 45° with a wiping movement
• 1B – Airflow EMS PLUS powder +conventional polishing with rubber cup and polishing paste of varying  RDA 170>120>40>7
• 2A – Ultrasonic EMS with PS instrument for 60 sec/ surface, brushstroke movements, pressure ~ 30p
• 2B – Ultrasonic + Airflow EMS PLUS powder used as above 
• 2C – Ultrasonic + conventional polishing used as above 
• 3A – Hand scaler/ curette. On enamel scaler curved. On root Gracey curette from  Deppeler blue, scaling movement per position one stroke 
• 3B – scaler/ curette + Airflow EMS PLUS powder as above
• 3C – scaler + Airflow EMS PLUS powder +Conventional polishing as above 
• 3D – scaler + conventional polishing as above
• Substance loss and roughness were assessed 2 control groups: enamel untreated, cementum untreated 

Results
On enamel: Group 1: Airflow
• There are no additional benefits in conventional polishing and Airflow in comparison to using AIRFLOW alone 

Group 2: Ultrasonic
• In comparison to Air-Flow, all other instrumentations produced small roughness values. Additional conventional polishing does not alter the overall results. 

Group 3: Hand instrument
• Hand instrument scaler also causes a loss of substance in the enamel. No additional improvement by additional instrumentation with Air-Flow, conventional polishing or a combination of both.

On cementum: Group 1: AirFlow
Slight roughness due to additional conventional polishing. 

Group 2: Ultrasonic
Ultrasonic produces  a smooth cementum surfaces with low roughness values, which are not significantly altered by combinations with Air-Flow or conventional polishing.

Group 3: Hand instrument
Gracey curette: A smooth surface is produced of the processed cementum, addition of Air-Flow worsens the result, polishing measures as already described above lead to an apparently smoother surface.

Conclusions

• Air-Flow with PLUS  powder produces the highest level of cleaning on enamel and cementum in comparison to ultrasonics or hand instrumentation.
• Repeated instrumentation, too high pressure  and too long exposure times lead to high substance loss with all systems.
• Use of conventional instrumentation leads of unnecessary over instrumentation especially in use on ceramics or restorations 
• Airflow is the most efficient solution providing maximum tooth preservation
• Ultrasound and hand instruments enable a stripe-shaped cleaning pattern through punctiform contact with the tooth surface. A planar pattern is achieved with Air-Flow. This makes it easier to achieve a homogeneous result on large surfaces. This is much more difficult with ultrasound and hand instruments and quickly leads to grooves and furrows.

Recommended treatment approach is:

• Assessment followed by disclosure for motivation
• Deep cleaning with Air-Flow followed by ultrasonic if necessary
• Quality check for remaining stains, biofilm or calculus