Dental Nitrous Oxide Systems: How to Choose.

A nitrous oxide system is the flowmeter, the scavenging circuit, and the gas supply. Nasal hoods and disposable circuits are supplies that attach to it. The existing nitrous product list covers those masks and circuits. This guide is about the machine that mixes oxygen and nitrous and keeps waste gas out of the room.

How to choose a nitrous system

• Fail-safe mixing. Dental flowmeters are built so nitrous cannot flow if oxygen fails, and so the mix cannot drop below a minimum oxygen percentage. Confirm that behavior on the unit you are quoted. A medical anesthesia machine is a different device.
• Scavenging. A nasal hood without a scavenger dumps exhaled nitrous into the operatory. The scavenger needs its own vacuum source, rated for that flow, not the high-volume evacuator the assistant uses during a prep.
• Central gas or portable cylinders. A plumbed office has oxygen and nitrous manifolds, alarms, and a closet full of H cylinders. A portable stand carries E cylinders and moves between rooms. Plumbing costs more up front and is the right choice if more than one room uses nitrous every day.
• Analog or digital display. Both styles set a total flow and a percentage. Digital units are easier to read from the assistant’s side. The clinical result is the same mix if the fail-safe works.
• Who services the gas. The flowmeter dealer and the medical-gas supplier are often different companies. Ask who changes cylinders, who certifies the lines, and who repairs the mixer.

How the two common systems differ

In the United States, quotes for dental nitrous almost always come down to Porter and Accutron. Treat the table as product differences, not a score.

Brand	Known for	Best fit	Watch for
Porter	MXR analog flowmeters and Matrx digital MDM units, plus the Silhouette scavenging mask	Offices standardizing on one mixer and one mask system	The mask is not the flowmeter. Quote them separately
Accutron	Digital Ultra flowmeters, often packaged with ClearView hoods	Offices that want a digital display and a HuFriedyGroup supply relationship	Confirm the scavenger vacuum inlet matches the vacuum you already have

Porter

Porter Instrument, part of Parker Hannifin, is the flowmeter a large share of U.S. offices already have on the wall or on a stand. MXR is the analog mixer. Matrx Digital MDM is the digital version of the same job. Silhouette is Porter’s low-profile scavenging mask, and it is sold as a breathing circuit, not as the mixer. If you already own Porter masks, staying with a Porter mixer avoids an adapter conversation. If you do not, choose the mixer and the mask as two line items.

Accutron

Accutron, now in the HuFriedyGroup, sells the Digital Ultra flowmeter and the ClearView single-use hoods. The digital head is the reason offices cross-shop it against Matrx. The hoods are the reason the package looks complete on a quote. Open the quote and find the scavenger connection. A hood that does not couple to your vacuum source is a mask, not a scavenging system.

Related guides

• Operatory equipment
• Nitrous masks, hoods, and circuits
• Dental vacuum systems
• Suction tips, traps, and line cleaners

Nitrous questions

Is a nasal hood the same as a nitrous system?

No. The hood delivers and scavenges at the patient’s nose. The system is the flowmeter and the gas supply. Replacing hoods does not replace a failing mixer.

Can I scavenge into the saliva ejector?

No. Scavenging vacuum is a continuous, metered draw sized for the nasal circuit. High-volume suction is a different line, used in the mouth, and it is off between patients. The scavenger should be connected the way the flowmeter maker specifies.