One failed result can be handled as a maintenance event. Close it out with a passing re-test and a record of the corrective action.
Follow the practice's failure-response procedure, treat the affected unit according to the manufacturer's instructions, and retest at the specified interval for the treatment and testing method. Record the failure, corrective action, and retest as one linked event.
Notify the infection-control lead and follow the practice's decision about clinical use while the result is investigated. If sampling or laboratory handling may have affected the result, review it with the laboratory without postponing the required failure response.
Isolate Before You Treat
Check the Obvious First
| Step 1 | Identify which unit or units failed, individually if the sample was pooled |
|---|---|
| Step 2 | Check for a lapse in the daily protocol before assuming product failure |
| Step 3 | Shock or treat per the product's instructions for use |
| Step 4 | Retest at the interval specified for the treatment and sampling method |
| Step 5 | Record the failure, the action taken, and the passing re-test as one event |
Begin with the affected unit's required response, notify the responsible clinician, and document its release-to-use decision. Then use the pattern below to investigate.
Check: Identify the included lines. Review refill dosing, bottle care, recent inactivity, and whether treatment reached connected accessories.
Follow up: Follow the required corrective action and obtain line-specific samples when directed to locate the problem.
Bottle and reservoir care →Check: Review a shared source-water change, product or lot change, preparation error, staff handoff, and collection/handling conditions.
Follow up: Notify the practice lead, address affected units under the protocol, and coordinate with the manufacturer or laboratory.
Source-water decisions →Check: Review excluded tubing, air pockets, damaged components, and attached equipment. Compare with units on the same protocol.
Follow up: Escalate to the equipment manufacturer or service technician rather than repeating the same step without investigating.
Equipment references →Check: Ask the laboratory about collection, neutralization, handling, and the reported method or detection limit.
Follow up: Resolve sampling questions while taking the required response to the reported failure. A suspected collection error is not a passing result.
Sample collection →Failures cluster into four causes, and they call for different responses. Repeating the same shock on a line that is failing for the third reason below will keep producing the same result.
| What it looks like | What to do | |
|---|---|---|
| Protocol lapse | One unit fails; the daily dose was missed, or a spare reservoir entered rotation untreated. | Shock, resume dosing, and close the gap that let an untreated reservoir onto the unit. |
| No baseline | The first test after starting a maintenance product fails, often well above the limit. | The lines were never shocked. Shock, then restart the maintenance protocol from a clean baseline. |
| Shock not reaching the line | The same unit fails repeatedly despite correctly performed shocks; other units on the same protocol pass. | Suspect an air pocket, a blockage, or a line excluded from the shock path. Involve your equipment technician. |
| Reintroduction | Results improve after a shock, then drift back up within weeks on every unit. | Look upstream: source water, reservoir handling, or a component that is not being treated. |
CDC notes that if a dental unit remains resistant to treatment over time, it may be necessary to replace the waterlines or other water-bearing components. Repeated failures on the same unit, after shocks that were performed correctly and that succeeded elsewhere in the practice, are the signal to stop repeating the treatment and involve the equipment manufacturer or a service technician.
There is no fixed number of failures that triggers replacement. The useful test is whether you can explain the failure. A second failure you can attribute to a missed dose is a process problem with an obvious fix. A second failure you cannot explain, on a unit whose neighbours pass on the same protocol, is a hardware question.
Procedures in the Meantime
A failure in the record is not a liability. A failure with no documented resolution is. Inspectors and investigators are looking for a functioning process, and a process that catches problems and closes them out is evidence that it works.
A printable log with these fields is on the testing log page.
Most second failures on a unit have the same cause as the first, because the shock addressed the biofilm and nothing addressed the reason it was allowed to establish.
Notify the infection-control lead and follow the practice's clinical-use and failure-response procedure, equipment instructions, and applicable state rules. Apply the prescribed treatment and retesting. Oral surgery needs an appropriate sterile irrigation system; California has an additional exposed-pulp provision. A failed routine water test should not be bypassed by assuming that changing the bottle alone resolves the problem.
At the interval specified for the corrective treatment and sampling method, rather than waiting for the routine testing cycle. Record the action, retest result, and authorized return-to-use decision together.
Usually one of three things: the shock solution is not reaching that line because of a blockage or an air pocket, the reservoir or a component on that unit is reintroducing contamination, or the daily protocol is being logged but not performed on that chair. Each has a different fix, so identify the cause before repeating the same treatment.
CDC notes that if a dental unit remains resistant to treatment over time, it may be necessary to replace the waterlines or other water-bearing components. Repeated failures on the same unit after correctly performed shock treatments are the signal to involve your equipment manufacturer or service technician.
Requirements vary by state and by equipment manufacturer. Always follow your dental unit and treatment product instructions for use, and confirm current rules with your state dental board.
LineTab attaches the daily dose to the reservoir refill: one tablet, no measuring, and a visible sign that it happened. Shocking and testing remain part of the protocol.