KaVo SMARTmatic S20 / S20 S Repair Guide: Getting Your 1:1 Contra-Angle Back to Full Strength

If the high-speed is the sprinter of the operatory, the 1:1 contra-angle is the marathon runner. The KaVo SMARTmatic S20 and S20 S handle restorative work at up to 40,000 rpm, appointment after appointment, often without anyone noticing them until something changes.

This guide explains exactly which S20 you have, what KaVo built into it, and how to approach a repair decision with confidence.

Which S20 Is on Your Delivery Unit?

KaVo's international SMARTmatic page lists two restorative contra-angles, both with a 1:1 transmission, a 40,000 rpm maximum operating speed, a 90° head angle and 2.35 mm contra-angle burs:

SMARTmatic S20 (Mat. no. 1.011.6750): without spray.
SMARTmatic S20 S (Mat. no. 1.011.6752): with external spray and internal spray handover.

KaVo's SMARTmatic FAQ confirms the S20 S simply adds the spray function and otherwise shares the S20's properties.

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A Regional Difference Worth Knowing

KaVo's international page describes the S20 and S20 S with a push-button chuck. KaVo's US page lists the S20 and an S20 K with a latch-type chuck. Check the markings on your handpiece before ordering parts or describing a fault.

What KaVo Built Into the S20

Ceramic sliders in the clamping system, which KaVo says provide enduring, secure tool holding.
Rust-free stainless steel for long-lasting durability.
Lightweight and optimum balance for precise, tireless work.
Internal spray transmission to the Sprayclip on the S20 S, for quick instrument changes on all motors.
Universal fit with dental chairs using air and electric motors to ISO 3694.

Signs Your S20 Needs a Technician

These are the changes we recommend taking seriously with any 1:1 contra-angle:

The head runs warm or hot during use
A new whine, rattle, or vibration
Speed that drops or becomes uneven
A correct 2.35 mm bur that does not stay secure
On the S20 S, weak spray. KaVo warns that too little spray water can damage the tooth and pulp through overheating.

Repair Decision Table

What You Notice	Likely Area	Try First	Usually Needs
Heat during use	Head, drive or spray supply	Stop and check spray (S20 S)	Bench evaluation
Uneven or dropping speed	Drive or contamination	Confirm KaVo servicing was done	Service
Bur loose or will not release	Chuck	Try a new 2.35 mm bur	Chuck repair
Leak or wobble on motor	Coupling O-rings	Replace all O-rings per KaVo care tips	Service if it continues
Weak spray (S20 S)	Clogged spray channels	Clean with KaVo nozzle needle	Service if spray stays weak

The Parts Question Every Practice Should Ask

In the instructions for its SMARTmatic S10 straight handpiece, KaVo warns that repairs made without original KaVo spare parts could let parts come loose and may count as a product modification affecting CE conformity. That principle is worth applying to your S20 too: ask any repair provider which parts they will use.

How We Evaluate an S20

Confirm the model and chuck type: S20, S20 S, or S20 K; push-button or latch.
Rule out the motor: coupling O-rings and the motor itself come first.
Run it free and under light load: we listen for noise and watch heat and speed stability.
Check bur grip and release with a correct 2.35 mm contra-angle bur.
Inspect the spray path on S20 S models.

Our Repair Process

Get in touch through our contact page or at 1-855-533-3399.
Ship it clean, serviced, and sterilized.
Bench evaluation confirms the fault.
Plain-language estimate, including which parts would be used.
Repair and run-test before it comes home.

Factory Repair and Warranty

KaVo runs its own factory repair service, KaVo REPAIR. If your S20 is new, check the warranty terms supplied with it before arranging outside service.

Keeping It Out of the Repair Queue

Maintain it only with KaVo Spray or QUATTROcare PLUS, as KaVo's SMARTmatic FAQ requires.
Never use Vaseline on O-rings, and never place the handpiece in or spray it with a descaling agent. KaVo warns descaling agents may cause corrosion.

KaVo SMARTmatic S20 Repair FAQs

Does the KaVo S20 have a push-button or latch chuck?

It depends on the market. KaVo's international page lists a push-button chuck for the S20 and S20 S, while its US page lists a latch-type chuck for the S20 and S20 K.

What is the difference between the S20 and S20 S?

According to KaVo, the S20 S adds a spray function. Otherwise, the two share the same properties.

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KaVo SMARTmatic S20 / S20 S Repair Guide | Repair.Dental