Part 3: Suction. Its complicated, or is it?

Welcome to the 3de part of our series, where we will delve into the complex world of dental suction units. This may be the toughest part of the series for many reasons, but I will strive to present the information in an easily understandable manner without overwhelming you with technical jargon.

Always consider is the Machine Fit-for-Purpose!

1. What is the regulation: BS EN ISO 10637.

High volume systems: vacuum system with an air intake of more than 250 l/min at each cannula, connector of the largest bore operating hose when operated at full power and in accordance with the manufacturer’s instructions.

A flow rate of >270 l/min is the key to avoid aerosols

2. Wet/Dry/Semi Dry.

In the past, water was commonly used to power a motor and create suction in dental equipment. Since the 1990s, water ring pumps have been prohibited in Europe in order to safeguard and conserve drinking water. However, as technology has advanced, this term has become outdated and caused confusion. Nowadays, the type of suction used in dental equipment is determined by where the separation of debris occurs, rather than the use of water.

To put it simply, there are three modern types of suction:

1. Wet suction: This type of suction system transports all debris from the patient's mouth through the pipes and separates it at the machine.
2. Dry suction: In this type of suction system, all debris from the patient's mouth is separated at the dental chair and not at the machine.
3. Semi-dry: This type of suction system is used in larger clinics with eight or more chairs, where debris from the patient's mouth is transported through a pipe and separated in a large tank.

These modern types of suction systems have replaced the old-fashioned water-powered motor and provide efficient and effective debris removal during dental procedures.

There may be slight variations in the piping layout and machine placement, such as whether it is positioned above or below the dental chair, or the distance from the chair. However, the primary consideration should be whether your dental chair setup is suitable for wet or dry systems, which depends on the presence of a separator in the chair.

3. Manifolds. (the HVE and LV cannulas)

This is where most of the restrictions to suction occur. For example, using a machine with 11mm HVE and 8mm suction hose will provide a suction flow rate of 140L/min, while using the same machine with 15mm HVE and 19mm suction hose will provide a flow rate of 350L/min. The suction power is limited by a narrow hose diameter, which results in an asymptotic progression.

4. Filters and pipes.

Consider the following as a starting point if your suction is not working:

• Have the filters on the chair and the machine been checked regularly?
• Are the hoses clogged, especially with prophy paste and powders?
• On older chairs have the internal hoses been checked for kinks or collapse?
• Are the pipes or hoses too small?
• Are there any leaks when HVE cannulas are close.
• how far is installed plumbing, diameter and how many 90degree angles.
• As a rule every 90 degree angle reduces negative pressure by 0.9 bar in contrast 2 x 45 degree only impacts by 0.3 bar.

5. Cleaning:

Proper cleaning and disinfection protocols are crucial to extend the lifespan of a suction machine. It is important to carefully read and follow the instructions for mixing and dosing cleaning and disinfecting solutions to ensure they are used correctly. Foam should be avoided as it can cause damage to any suction machine. To maintain clean and healthy pipes and machines, it is recommended to rinse the suction line with clean cold water between patients as part of the standard operating procedure. This will have a positive effect on the cleanliness and longevity of the suction machine.

This just covers the surface and I always recommend before changing or buying any suction machine consider asking the following questions and clearly understanding the answers.

1. How many chairs will it service?
2. Is my chair set up for dry or wet suction?
3. Am I replacing like for like?
4. What is my current need and will i need more in future?
5. Is the machine going to be above, below or same level as my practice.
6. How did i look after my current machine?

Feel free to like, comment and share.

Keep an eye out for Part 4 next week: Conclusion!