- Owner
- Sterilization Coordinator
- Effective date
- September 15, 2026
- Review cycle
- Every 12 months
1.Purpose
To keep water delivered through dental unit handpieces and syringes within accepted quality limits by controlling biofilm buildup in the waterlines.
2.Scope
Applies to dental unit waterlines feeding handpieces, air-water syringes and ultrasonic scalers in all operatories. Municipal water supply and plumbing are outside this SOP.
Definitions
- Biofilm
- A layer of bacteria that forms on the inside of waterline tubing and can contaminate water delivered to the patient.
- Shock treatment
- A periodic chemical treatment used to break down and remove biofilm from waterline tubing.
- Water quality test
- A test, typically using a self-contained test kit or independent lab, that measures bacterial contamination in dental unit water.
3.Responsibilities
- Dental Assistant
- Performs daily flushing, changes treatment cartridges and records completed tasks.
- Sterilization Coordinator
- Schedules shock treatments and water quality testing and tracks results.
- Dentist
- Reviews failed water quality results and decides whether a unit is taken out of service.
RACI matrix
| Activity | Dental Assistant | Sterilization Coordinator | Dentist |
|---|---|---|---|
| Perform daily waterline flushing | R/A | I | - |
| Perform periodic shock treatment | R | R/A | I |
| Test water quality | R | R/A | I |
| Respond to a failed water quality result | I | R | R/A |
R = Responsible, A = Accountable, C = Consulted, I = Informed
4.Materials and PPE
Materials, tools and systems
- →Waterline treatment or shock treatment chemical
- →Self-contained water quality test kit
- →Independent testing lab service, if used
- →Waterline maintenance log
- →Manufacturer's instructions for each dental unit
Personal protective equipment
- →Disposable gloves
- →Eye protection when handling shock treatment chemical
5.Procedure
- 5.1
Flush lines at the start of the day
Dental AssistantBefore seeing the first patient, flush each dental unit's waterlines and air-water syringe for the manufacturer's recommended time to clear standing water.
- 5.2
Flush lines between patients
Dental AssistantFlush handpieces and air-water syringes for the manufacturer's recommended time between patients to clear water that may have been drawn back into the line.
Checkpoint: Between-patient flushing is completed and documented before the next patient is treated.
- 5.3
Change or replenish waterline treatment
Dental AssistantChange waterline treatment cartridges or add treatment solution to the unit's water reservoir on the manufacturer's recommended schedule.
- 5.4
Flush lines at the end of the day
Dental AssistantFlush each unit's waterlines again at the end of the clinical day to reduce standing time in the lines overnight.
- 5.5
Schedule periodic shock treatment
Sterilization CoordinatorSchedule shock treatment for each dental unit's waterlines on the interval recommended by the unit and treatment manufacturer to break down existing biofilm.
- 5.6
Perform the shock treatment
Dental AssistantFollow the shock treatment product's instructions for concentration, contact time and rinse cycle for each affected dental unit.
Warning: Never mix shock treatment chemicals with other cleaning products, and rinse thoroughly before the unit is used on a patient.
- 5.7
Confirm the unit is rinsed and ready
Dental AssistantRun a full rinse cycle after shock treatment and confirm no chemical odor remains before returning the unit to clinical use.
- 5.8
Test water quality on schedule
Sterilization CoordinatorCollect a water sample from each dental unit on the practice's testing schedule using the self-contained test kit or independent lab process.
- 5.9
Review water quality results
Sterilization CoordinatorCompare each unit's result against the accepted water quality limit for dental treatment water and log the result by unit and date.
Checkpoint: Every unit's water quality result is reviewed against the accepted limit and logged before the unit continues routine use.
- 5.10
Take a failing unit out of service
DentistIf a unit fails water quality testing, take it out of service for non-surgical use as directed by the dentist until it is retreated and retested successfully.
Warning: Do not use a dental unit that has failed water quality testing until it passes a retest after treatment.
- 5.11
Retreat and retest a failed unit
Dental AssistantRepeat shock treatment on the affected unit and retest before returning it to normal clinical use.
- 5.12
Maintain the waterline maintenance log
Sterilization CoordinatorKeep flushing, shock treatment and water quality test results current in the waterline maintenance log for every dental unit in the practice.
6.Quality checks
- →Daily and between-patient flushing is documented for every operatory.
- →Water quality testing is completed on schedule for every dental unit.
- →No unit with a failed water quality result is used until it passes a retest.
- →Shock treatment is completed on the manufacturer's recommended interval.
7.Records
- →Waterline maintenance and flushing log
- →Shock treatment records by unit
- →Water quality test results
- →Out-of-service and retest log for failed units
8.KPIs
- →Water quality test pass rate
- →Percentage of units with flushing completed on schedule
- →Time a failed unit stays out of service
- →Shock treatment compliance rate
9.Common mistakes
- →Skipping between-patient flushing when the schedule is busy.
- →Using a dental unit again right after shock treatment without a full rinse cycle.
- →Letting water quality testing lapse past the scheduled interval.
- →Continuing to use a unit for non-surgical care after it failed testing without retreating it.
10.Revision history
| Revision | Date | Description | Reviewed by |
|---|---|---|---|
| 1.0 | September 15, 2026 | Initial release | Ilia Pirozhenko |
This is a template. Adapt it to your organization, equipment and local regulations before use.
