Dental Equipment Glossary

How to Use This Glossary

Terms are grouped into six areas: imaging, digital dentistry and CAD/CAM, instruments and handpieces, sterilisation and infection control, clinic infrastructure, and rental and finance. Where a term appears in a specification table on one of our category pages, the definition explains what the number means and what to look out for. Standards are referred to by their international designations; local regulations may add further requirements.

Imaging

ALARA / ALADA

As Low As Reasonably Achievable / As Low As Diagnostically Acceptable. The radiation-protection principle that every exposure must be justified and that dose should be kept as low as possible while still answering the clinical question.

Bitewing

An intraoral radiograph showing the crowns of upper and lower posterior teeth on one image, used mainly to detect interproximal caries and assess crestal bone levels.

CBCT (cone-beam computed tomography)

A 3D imaging technique that rotates a cone-shaped X-ray beam and a flat-panel detector around the head to reconstruct a volume. Used for implant planning, endodontics, impacted teeth and airway assessment. Dose and image quality depend on field of view and voxel size.

Cephalometric (ceph) radiograph

A standardised lateral or postero-anterior skull radiograph used in orthodontics to measure skeletal and dental relationships. Usually taken with a ceph arm attached to a panoramic unit.

Collimation

Restricting the X-ray beam to the area of interest. Rectangular collimation for intraoral radiographs reduces patient dose compared with a round collimator, and is recommended by many radiation-protection bodies.

DICOM

Digital Imaging and Communications in Medicine — the international standard file format and network protocol for medical images. DICOM compatibility lets CBCT and panoramic images be viewed and shared across different software and with other clinicians.

Field of view (FOV)

The size of the volume captured in a CBCT scan, for example 4 × 4 cm for a single tooth or 16 × 13 cm for both jaws. A smaller FOV usually means lower dose and often higher resolution.

Line pairs per millimetre (lp/mm)

A measure of spatial resolution: how many pairs of black and white lines a detector can distinguish within a millimetre. Higher numbers indicate finer theoretical detail, though perceived image quality also depends on noise and processing.

Panoramic radiograph (OPG / OPT)

A single 2D image of both jaws, all teeth, the temporomandibular joints and the maxillary sinuses, produced by a tube and detector rotating around the patient's head. Used for overall assessment, third molars and orthodontic planning.

Periapical radiograph

An intraoral radiograph showing an entire tooth from crown to root apex and the surrounding bone, used for endodontic diagnosis, periapical pathology and root morphology.

Phosphor storage plate (PSP)

A thin, reusable, wireless imaging plate that stores the latent X-ray image and is read by a laser scanner. Flexible and comfortable but slower than a direct sensor and susceptible to scratches.

Sensor (CMOS / CCD)

A rigid digital intraoral detector connected by cable or wirelessly to a computer, producing an image in seconds. Most current sensors use CMOS technology. Available in sizes 0, 1 and 2 for different mouth sizes.

Voxel

The 3D equivalent of a pixel — the smallest unit of a CBCT volume. Smaller voxels (for example 75–100 µm) give finer detail for endodontics, while larger voxels reduce dose and file size for implant planning.

Digital Dentistry & CAD/CAM

CAD/CAM

Computer-aided design and computer-aided manufacturing. In dentistry, restorations are designed in software from a digital scan and then milled or printed, either chairside in a single visit or in a laboratory.

Chairside workflow

A digital workflow in which a restoration is scanned, designed, milled or printed, finished and fitted during the same appointment, typically for inlays, onlays and single crowns.

DLP / LCD / SLA printing

Vat photopolymerisation 3D-printing technologies that cure liquid resin with light. DLP uses a projector, LCD (or MSLA) uses a masked screen and SLA uses a laser. All are used for models, surgical guides, splints and temporaries.

Intraoral scanner (IOS)

A handheld optical device that captures a 3D digital impression of teeth and soft tissues, replacing conventional impression materials for crowns, aligners, implants and study models.

Milling unit (wet / dry)

A machine that cuts restorations from blocks or discs. Wet milling cools with water and is used for glass ceramics and composites; dry milling is used for zirconia and PMMA. Many units do both.

Open vs closed system

An open system exports scans in standard formats (such as STL, PLY or OBJ) that any lab or software can use. A closed system restricts data to the manufacturer's own software, lab network or mills, sometimes with fees to export.

Post-curing unit

A UV or light chamber used after 3D printing to fully polymerise resin parts. Correct post-curing is essential for the mechanical properties and biocompatibility of printed medical devices.

Sintering furnace

A high-temperature furnace (typically 1,450–1,600 °C) that densifies milled zirconia restorations, which shrink by around 20–25% during the process. Speed-sintering furnaces shorten cycles for chairside use.

STL file

Standard Tessellation Language — the most widely used file format for 3D surface geometry. It describes shape but not colour; PLY and OBJ formats can also store colour texture from scanners.

Trueness and precision

The two components of scanner accuracy. Trueness is how close a scan is to the real object; precision is how consistent repeated scans are. Both are typically reported in micrometres.

Instruments & Handpieces

Air turbine

A high-speed handpiece driven by compressed air, typically running at 300,000–450,000 rpm. Light and inexpensive, but torque drops under load, and speed is less consistent than with an electric handpiece.

Apex locator

An electronic device that measures root canal working length by detecting changes in electrical impedance as the file approaches the apical foramen, reducing the need for length-determination radiographs.

Contra-angle (CA) handpiece

A handpiece with a bend in the shank to improve access to posterior teeth. Colour-coded rings indicate gear ratio: commonly blue for 1:1, green for reduction (for example 4:1 or higher) and red for speed-increasing (1:4 or 1:5).

Delivery system

The arrangement of the dentist's instruments on a dental unit: over-the-patient (continental or international), side delivery or rear delivery. It determines ergonomics, assistant access and what the patient sees.

Electric micromotor

A brushless electric motor that drives contra-angle and straight handpieces. With a speed-increasing contra-angle it can reach around 200,000 rpm with constant torque, giving precise and quieter cutting than an air turbine.

Endodontic motor

A low-speed motor with torque and speed control for rotary or reciprocating nickel-titanium files, often with an integrated apex locator and auto-reverse to reduce file separation.

Fibreoptic handpiece

A handpiece with a built-in light (LED or halogen via fibreoptic bundle) at the head, illuminating the working field directly.

Piezoelectric scaler

An ultrasonic scaler that uses piezo crystals to produce linear tip movement, typically at 25–50 kHz. Used for calculus removal, endodontics and, in surgical versions, bone cutting.

Torque (Ncm)

Rotational force, measured in newton-centimetres. Implant motors are usually rated up to 50–80 Ncm, and implant insertion torque is monitored to assess primary stability.

Triplex (three-way) syringe

The chairside syringe that delivers air, water or a combined spray, used for rinsing and drying the field.

Sterilisation & Infection Control

Bowie–Dick test

A daily test of air removal and steam penetration in vacuum autoclaves, originally designed for porous loads. Dental practices commonly use a Helix test instead or alongside, as it better represents hollow instruments.

Class B autoclave

A small steam steriliser (as defined in EN 13060) with fractionated pre-vacuum, capable of sterilising wrapped, porous and hollow (lumen) instruments such as handpieces. The standard choice for modern dental practices.

Class N and Class S autoclaves

Class N autoclaves are for unwrapped solid instruments only. Class S autoclaves are validated by the manufacturer for specific load types, which may include some wrapped or hollow items.

Critical, semi-critical and non-critical items

The Spaulding classification: critical items penetrate tissue and must be sterile; semi-critical items contact mucosa and need sterilisation or high-level disinfection; non-critical items touch intact skin and need cleaning and disinfection.

Decontamination room (CDU)

A dedicated room for cleaning, disinfecting, inspecting, packing and sterilising instruments, arranged in a one-way flow from dirty to clean to prevent recontamination.

Helix test (PCD)

A process challenge device consisting of a long narrow tube with an indicator strip, used to check that steam penetrates hollow instruments during a Class B cycle.

Indicators (chemical / biological)

Chemical indicators change colour when exposed to sterilisation conditions; type 4–6 indicators respond to several parameters. Biological indicators contain resistant bacterial spores and provide the most direct evidence of sterilisation.

Ultrasonic cleaner

A tank that uses high-frequency sound waves to create cavitation bubbles that dislodge debris from instruments before sterilisation. It cleans but does not disinfect or sterilise.

Validation (IQ / OQ / PQ)

Documented proof that equipment works as intended: installation qualification (installed correctly), operational qualification (operates within specification) and performance qualification (achieves the required results with actual loads).

Washer-disinfector

A machine that cleans and thermally disinfects instruments in a validated, reproducible cycle, defined by the ISO 15883 series. A₀ is the measure of thermal disinfection; an A₀ of 3000 is widely used for instruments.

Waterline biofilm

Microbial film that forms inside the narrow tubing of dental unit waterlines. Controlled with continuous or periodic disinfection, flushing and monitoring of water quality.

Clinic Infrastructure

Amalgam separator

A device fitted to the suction system that captures amalgam particles before wastewater enters the drain. ISO 11143 requires a separation efficiency of at least 95%; many units achieve 99% or more, and regulations in many regions require them.

Backflow prevention (air gap)

Measures that stop contaminated water from flowing back into the mains supply. Dental units typically need a fluid category 5 protection such as a type AA or AB air gap, depending on local water regulations.

Dew point (pressure dew point)

The temperature at which moisture condenses from compressed air. A dryer lowers the dew point so that water does not condense in air lines, handpieces and instruments.

Dry vacuum suction

A suction system in which fluids are separated from air close to the chair, so the vacuum pump handles only air. More water-efficient than wet-ring systems.

Free air delivery (L/min)

The volume of air a compressor delivers at a given pressure, measured in litres per minute. Compressor sizing is based on the number of chairs used simultaneously and the air consumption of each.

High-volume evacuation (HVE)

Large-bore suction (typically 11–16 mm tips) operated by the dental assistant to remove fluids, debris and aerosols. Requires a suction system capable of high airflow at the chair.

Oil-free compressor

A compressor that does not use oil in the compression chamber, preventing oil contamination of the air delivered to handpieces and the patient's mouth. Standard for dental use.

Plant room

A ventilated room housing the compressor, suction pump and associated equipment, ideally acoustically separated from treatment areas and accessible for servicing.

Wet-ring vacuum

A suction pump that uses a ring of water to create vacuum, robust and tolerant of fluids but with ongoing water consumption.

Operatory light (lux, CRI)

Dental operating lights are rated by illuminance in lux (typically 15,000–50,000 at the working distance) and colour rendering index (CRI). A CRI of 90 or more and an adjustable colour temperature help with shade matching.

Rental & Finance

Buy-out option / residual value

The right to buy rented equipment at the end of the term at a set price (the residual value) or at fair market value. Agree the figure in writing before signing if you think you may want to keep the equipment.

Capital allowance / depreciation

Ways of spreading the cost of purchased equipment over its useful life for accounting or tax purposes. Rules and rates differ by country and change over time, so check with an accountant.

Early termination fee

The charge for ending a rental before the minimum term expires, often a percentage of the remaining payments. Check how it is calculated and whether it reduces if you upgrade with the same supplier.

End-of-term options

What you can do when the rental term ends: return the equipment, renew (often at a reduced rate), upgrade to newer equipment or buy it.

Hire purchase / lease-to-own

An agreement in which you pay for equipment in instalments and ownership transfers to you at the end, often after a final nominal payment. Usually treated more like a purchase than a rental for accounting purposes.

Loan unit / rental credit

A replacement provided while rented equipment is being repaired, or a credit against rental payments if no replacement is available within an agreed time. One of the most important clauses in any rental contract.

Minimum term

The shortest period for which the rental must run, commonly 12, 24, 36 or 60 months. Shorter terms usually have higher monthly rates.

Operating vs finance lease

Accounting categories describing whether a lease mainly transfers the use of an asset (operating) or effectively transfers its ownership risks and rewards (finance). Many accounting standards now put most longer leases on the balance sheet.

Service level agreement (SLA)

The part of a contract that defines service standards, such as breakdown response time (for example next business day), maximum repair time, preventive maintenance frequency and what happens if the targets are missed.

Total cost of ownership (TCO)

The full cost of owning equipment over its life: purchase price, financing, software, service, consumables, testing, downtime and disposal, minus resale value. The fair basis for comparing a purchase with a rental.

Upgrade right

A contract clause allowing you to exchange equipment for a newer model during or at the end of the term, sometimes with a new term starting and a revised monthly rate.