Disinfectants 101: choosing and using products in dental practice

Cleaning, disinfection, antisepsis and sterilization

Cleaning removes contamination. Blood, saliva and other organic material can interfere with subsequent decontamination. After cleaning, an instrument must complete the other processing steps required before it can be used again.

Disinfection destroys or inactivates microorganisms under specified conditions. The antimicrobial spectrum identifies the groups against which the product acts; concentration and contact time affect that activity. Not every disinfectant destroys bacterial spores.

Antisepsis treats living tissue. Use a product intended for that particular tissue. A worktop disinfectant is not a skin product, and a skin antiseptic is not automatically suitable for oral mucosa.

Sterilization destroys viable microorganisms, including bacterial spores. A “sporicidal” claim on a chemical product does not establish that an instrument has undergone a suitable, validated sterilization process.

Determine the required outcome before selecting the product. A surgical instrument requires sterilization; immersion in a disinfectant solution is insufficient. A light handle needs a product compatible with its surface, while hands require a hand hygiene product.

How the instrument's use determines processing

Devices fall into three categories according to the tissues they contact:

For every category, also follow the instructions for the particular device. For a heat-sensitive semicritical device, CDC recommends first seeking a heat-tolerant or disposable alternative. If neither is available, the guidance specifies high-level disinfection as a minimum. Dental handpieces are an exception: they must be cleaned and heat-sterilized between patients. The selected process must also comply with Bulgarian requirements.

Choose by intended use

Before comparing alcohols, oxidizing agents or ammonium compounds, identify the task:

A separate product is not necessarily needed for every task. One product may have several authorized uses, but each must be supported by its documentation.

Main active-substance groups

The active substance gives you an indication of how a disinfectant works and its possible limitations. To choose a product, you still need the data for its complete formulation: which microorganisms it acts against, at what concentration, for how long and on which materials.

For a product containing several active substances, assess the entire formulation. Having two active substances does not, by itself, show that a product is better suited to your task. An “alcohol-free” label is also insufficient: you still need to check the antimicrobial spectrum, contact time, material compatibility and safe handling instructions.

Professional products may contain amines or other active substances. Products from the same chemical group can have different spectra, concentrations and exposure times. Compare current instructions for the exact products.

Read the antimicrobial claims precisely

Identify whether the label claims activity against bacteria, yeasts, fungi, mycobacteria, viruses or bacterial spores. These claims are not equivalent. Activity against enveloped viruses does not mean activity against all viruses; evidence against yeasts does not establish activity against all fungi.

A product may require different contact times for different microorganisms. The shortest advertised time may cover only part of its spectrum. Compare products for the same task, recording spectrum, concentration, time and test conditions together.

For example, two packs of wipes labelled “virucidal” may require different contact times. Check the time for the required activity and whether each wipe is compatible with the surface you will treat.

What EN standards tell you

A standard number identifies a test or assessment framework. It is not a standalone authorization for use in Bulgaria.

A suspension test evaluates activity in a liquid environment. A surface test evaluates conditions closer to the corresponding use. For wipes, the disinfectant liquid, wipe material and wiping action all matter. Test results for a liquid concentrate do not establish that it will work equally well with every cloth soaked in it.

Check the edition too. On 19 October 2026, DIN's catalogue lists EN 14476:2025 and EN 16615:2026. An older report is not automatically invalid because of its year; ask whether it supports the claims in the current product documentation. Public catalogues describe scope; full test methods are in the standards themselves.

Use the specified concentration for the full contact time

Effectiveness depends on concentration, contact time, temperature, contamination and whether the product can reach the entire surface being treated. Do not shorten contact time by increasing concentration, or change temperature and dilution to accelerate treatment.

Follow the surface-wetting instructions. If a surface dries too quickly, check the instructions for applying the product and maintaining contact for the full required time. For immersion, solution must reach every part requiring disinfection, including internal channels. Use immersion only where permitted for the device.

Calculating the amount of concentrate

If the instructions specify a 2% product solution by volume with a final volume of 1,000 ml, the calculation is 1,000 × 2 / 100 = 20 ml. Measure 20 ml of product and add water to a total volume of 1,000 ml. Do not add it to an already measured 1,000 ml of water.

The 2% figure illustrates the calculation; it is not a recommended concentration. Use the concentration in the particular product's instructions. This calculation does not automatically apply to mass percentages, active-substance percentages, tablets or special dosing systems. “2% product” differs from “2% active substance”. Seek written clarification before preparing a solution with ambiguous instructions.

Comparing ready-to-use solutions, concentrates and wipes

Ready-to-use solutions are not diluted. Check how long they can be used after opening, how to store them and how to apply them. When comparing concentrates, include the work involved in measuring and diluting them. For wipes, check how much surface each wipe can treat, how long the pack can be used after opening, how it must be closed and when a fresh wipe is needed.

Leave a cell blank if you lack the supporting information. Ask the supplier to clarify it before adding the product to your practice procedure. For the steps between patients, continue with the practice workflow and Bulgarian requirements.

US EPA or FDA registration does not replace the authorization or conformity evidence required for the Bulgarian market.