Tuttnauer EZ11 Plus vs Midmark M11: A 7-Step Checklist From Someone Who's Made Every Mistake

If you're deciding between the Tuttnauer EZ11 Plus and the Midmark M11, this checklist is for you. It's built from seven years of buying and troubleshooting tabletop sterilizers for dental clinics and small labs — and yes, some of those buying decisions went badly. Six significant mistakes, roughly $13,700 in wasted budget. This is the checklist I wish I'd had.

Who This Checklist Is For

Dental practices sterilizing handpieces, veterinary clinics running daily instrument cycles, and small labs that batch-process tools. If you fit that profile, you'll get something useful out of these seven steps.

My experience is based on about 200 sterilization-related orders, most of them mid-range tabletop autoclaves. If you're running a high-volume central sterile department, your needs are different, and this checklist probably isn't enough for you.

The 7-Step Checklist

Step 1: Map Your Instrument Mix Before Comparing Specs

Both the EZ11 Plus and the M11 are 11-liter chamber autoclaves. That's the easy part. The harder part is what you plan to put inside.

If you're sterilizing dental handpieces — and let's be honest, that's probably why you're here — check whether the cycle you intend to use is validated for handpiece sterilization. The EZ11 Plus runs vacuum-assisted cycles that handle wrapped and unwrapped instruments well. The M11 does too. But here's what nobody tells you during the sales demo: the air trapped inside a handpiece's internal channels behaves differently than air around solid instruments. Not every 11-liter autoclave achieves the vacuum depth your specific handpieces need.

That's exactly the mistake I made in 2019. The specs looked identical on paper — same chamber size, similar cycle menu. But our handpieces required a deeper vacuum than that unit could pull. The autoclave was $3,200. The wasted budget wasn't the machine, though. It was the disruption, the rescheduling, and the week we had to outsource our sterilization to a lab across town. That week cost us more in client trust than the machine cost in dollars.

Step 2: Compare Floor-to-Floor Cycle Time, Not Just Listed Cycle Time

Manufacturers list cycle times. In my experience, the real number — from pressing start to opening the door — is always longer. The EZ11 Plus advertises a fast cycle around 20 minutes at 121°C. The M11 lists similar numbers. But floor-to-floor, including heat-up, drying, and chamber cool-down, we've measured both at 35–40 minutes in real clinic conditions.

The surprise wasn't the price difference. It was how much the warm-up time varies based on your water temperature, room ventilation, and how often the door is opened. If your reception area crowds with patients at 9 AM and you need instruments ready by 10, those extra minutes matter.

Ask for the full cycle time — not the sterilizing phase only. Better yet, ask a current owner, not a salesperson. Period.

Step 3: Verify Water Quality Requirements Against Your Plumbing

Both units specify Type III water or better — distilled or deionized. The EZ11 Plus can be configured with an external water line connection. The M11 uses a rear reservoir. Either way, tap water is not an option.

We ran one clinic's unit on tap water for two weeks while the distilled water supplier sorted out a delivery issue. The scale buildup destroyed the heating element. Repair bill: $890. The lesson: if you don't have a reliable distilled water source, the autoclave isn't the only thing you're buying.

Step 4: The Overlooked One — Printout Quality and Record Keeping

Almost everyone checks chamber size, price, and cycle time. Almost nobody checks the quality of the cycle printout. Until an inspector asks for 18 months of sterilization logs.

Both units produce a thermal paper printout for every cycle. Thermal paper fades. We learned this the hard way when roughly half of our records from the previous year were too faded to read. That was a painful conversation with a state health inspector.

Since Q3 2023, we scan every printout and store it digitally. A $20 scanner and a shared drive. That's it. But I've never once seen this addressed in a sales presentation — from either brand.

Step 5: Measure Clearance Around the Unit, Not Just Footprint

The EZ11 Plus measures roughly 45 × 37 cm. The M11 has a slightly different footprint. But you also need clearance on the sides for airflow, space above for loading, and enough room in front for the door to swing open completely.

In 2021, we installed a unit in a space that fit the footprint perfectly. The door couldn't open fully because of a shelf we'd already mounted. The service technician charged $250 for the visit and we rearranged the entire room. Simple. Obvious. Totally missed.

Step 6: Get Service Response Times in Writing

Tuttnauer has been in the sterilization business since 1925 and operates a broad authorized service network across the US. Midmark is also well established in dental and medical equipment. But service response times vary by region — significantly.

We had a unit failure on a Friday in March 2024. The nearest authorized technician for one brand had a 10-day wait. The other brand's partner came in four. I won't tell you which brand was which, because your local coverage will differ. I will tell you to ask for response time commitments in writing. It should not feel like an unreasonable question.

Also ask about calibration logistics. Both brands require periodic sensor calibration. Shipping calibration assemblies gets more expensive each year — USPS rates alone raised our calibration return shipping cost from $18 in 2022 to $26 as of January 2025 (per usps.com pricing). Ask if an on-site technician can verify temperature sensors instead. It saves money and downtime.

Step 7: Put Every Hidden Cost on a Spreadsheet

Before you compare any two autoclaves, add these line items to both sides:

• Installation — is it included?
• Water purification — system purchase or ongoing distilled water cost
• Biological indicator tests — spore tests, recommended weekly
• Chemical indicators — pouches, tape, strips
• Thermal paper rolls — small cost, infinite annoyance when you run out
• Annual calibration — and what it costs with travel time

A $4,500 autoclave becomes a $6,000+ autoclave in its first year of real operation. I've seen practices skip weekly spore testing to save roughly $12 per test. That's the most dangerous corner to cut. Per FTC advertising guidelines (ftc.gov), manufacturers must substantiate their claims about what their sterilizers achieve. In the same spirit, you need to substantiate that your sterilizer is achieving it in your clinic. Biological indicators are the only way to do that. Weekly. No exceptions.

Common Mistakes I've Made (So You Don't Have To)

The Communication Failure

I once emailed a supplier: "We need the 115V version." They confirmed: "Yes, 115V." The unit arrived with a NEMA L5-30 plug. Our wall outlets are NEMA 5-15. We were using the same words but meaning different things.

The adapter cost $140 and delayed installation by three days. Now, every purchase order specifies the plug type, not just the voltage.

The Handpiece Reality Check

A single dental handpiece can cost $1,200–$2,500. If your sterilizer doesn't process them correctly, you're not risking the handpiece — you're risking patient safety. That's not dramatic language, that's the job. If you're not sure whether your clinic's handpieces are compatible with a given autoclave's cycles, get it in writing from the manufacturer.

The same logic applies in labs. We run a biosafety cabinet in our lab, and new staff sometimes assume the HEPA filtration sterilizes everything processed inside it. It doesn't. The cabinet protects the sample and the operator from airborne contamination — it doesn't kill bacteria on instrument surfaces. Items from a biosafety cabinet still go through the autoclave. The cabinet is not a sterilizer.

What Does Ultrasound Show?

I get this question a lot from new staff: "What does ultrasound show?" In instrument processing, an ultrasonic cleaner uses cavitation — microscopic bubbles that collapse and knock debris off instrument surfaces. It's an essential cleaning step, but it is not sterilization. It doesn't kill spores. It doesn't remove all proteins. The autoclave is where sterilization happens.

Understand the full workflow before you buy any autoclave:

1. Clean — ultrasonic or manual
2. Rinse and dry
3. Package or wrap
4. Sterilize — autoclave
5. Store and document

Skip step one or two, and your autoclave is just an expensive jewelry box.

So, EZ11 Plus or M11?

Both are reliable machines. The EZ11 Plus handles our external water connection neatly, and the vacuum system performs well with dental handpiece cycles. The M11's chamber shape works better in one of our satellite clinics, and that's fine. The honest answer is that either unit can serve a dental practice well.

"You're not buying an autoclave. You're buying the confidence that your instruments are sterile. Those are two different purchases."

One more observation from the last seven years: patients rarely see the autoclave. But every clinical staff member knows exactly what it is, whether it's running on time, and whether it's a backup unit held together with hope. Your team's confidence in your equipment directly affects how they talk about your practice — with each other, and sometimes within earshot of patients. That's the brand impact that never appears in a spec sheet.

A $500 difference in the right autoclave is nothing against the cost of the wrong one. The right instrument is the one you can maintain, document, and trust every single morning. Run the checklist, get the answers in writing, and buy the machine that lets you stop thinking about sterilization altogether.