- Position Paper of the Organization for Safety & Asepsis (OSAP), the specialized experts, on Dental Waterlines Contamination.

Statement: The numbers of colony-forming units in water used as a coolant or irrigant for non-surgical dental treatment should be as low as reasonably achievable and, at a minimum, must meet nationally recognized standards for safe drinking water. Non-surgical procedures include most subgingival scaling or restorative procedures as well as initial access into the dental pulp.

Rationale: The 1995 ADA goal encouraged the development of methods to reliably produce dental treatment water that contains fewer than 200 CFU/mL of heterotrophic mesophilic water bacteria. The ADA goal was derived from engineering standards established in the field of hemodialysis, where colony counts higher than 200 CFU/mL have been linked to pyrogenic reactions in patients. This goal remains a viable engineering standard for manufacturers of devices or chemical agents intended to improve the quality of dental treatment water.

The Environmental Protection Agency (EPA), the American Public Health Association (APHA) and the American Water Works Association have set a maximum limit for heterotrophic mesophilic water bacteria in drinking water at 500 CFU/mL [15, 16]. While it is clear that dental water should contain colony counts that are as low as reasonably achievable, there is little scientific evidence that water that meets drinking water standards poses a health hazard for immune-competent individuals. Although procedures within the gingival sulcus may technically expose the vascular system, sulcular tissues are already colonized with microorganisms. The decision to use clean or sterile water during such procedures should be based on the invasiveness of the procedure, the patient’s immunologic status, and other potential risk factors for infections, such as infective endocarditis.

Since initial access into the pulp chamber may be performed in conjunction with restorative dental procedures, the use of dental unit water that meets drinking water standards is acceptable for endodontic access procedures, but sterile solutions are preferred for subsequent canal preparation and are required for endodontic surgery.

Statement: Sterile solutions that meet the appropriate standards described in the United States Pharmacopoeia (USP) should be used for all dental procedures that involve the intentional penetration, incision, excision, abrasion, or ablation of intact, non-sulcular oral mucosa to expose normally uncontaminated soft tissue or bone.

Rationale: OSAP concurs with the 1993 recommendation of the CDC that only sterile solutions should be used for surgical procedures that involve the cutting of bone [12]. The OSAP statement further clarifies this position by including all other surgical procedures that expose normally uncontaminated tissues and result in penetration of the vascular system. The USP sets standards for sterile solutions that assure that they are free of viable microorganisms and have acceptably low levels of bacterial endotoxin and other potentially harmful substances

 

more at: http://www.osap.org/issues/pages/water/duwl.htm