INTRODUCTION
Dr. Gerald Moyer, a dentist, and John Mattingly, an engineer, introduced the first dental water jet, called the Octopus in 1962. Since that time, professional opinion on the benefits of using a dental water jet has fluctuated but the research has always been consistently positive. The dental water jet has demonstrated the ability to reduce inflammation and bleeding in some cases better than what can be achieved with normal brushing and flossing.1-5

MECHANISM OF ACTION
The dental water jet works through the direct application of a pulsed stream of water or other solution. Studies by Bhaskar et al and Selting et al have found pulsation and pressure to be critical components of a dental water jet. Pulsating devices have been shown to be three times as effective as continuous stream syringe-type devices.6 Pulsation provides for a compression
and decompression phase that allows for expedient clearing
of bacteria from the pocket. A pulsating device also allows for control of the pressure rate.7 A medium to a high setting (50 psi - 90 psi) has been shown to be the most effective.

DEPTH OF DELIVERY

evidence seems to indicate that the dental water jet has the greatest potential for subgingival access into the periodontal pocket.10,11,13 Studies documenting subgingival access in-vivo
for toothbrushing and flossing are limited. The ability of a sonic toothbrush to have an effect on bacteria subgingivally has been tested only in the laboratory setting and has not been proven definitively in-vivo.14,15,16 One clinical trial by Williams et al compared the disruption of plaque and bacteria from a sonic and a manual toothbrush after 15 seconds of brushing time and found both removed plaque and microbes up to 1 mm.17

The use of a standard jet tip on the dental water jet is called supragingival irrigation. It is accomplished by the tip on the left in Figure 3. The point of delivery is at or coronal to the gingival margin resulting in penetration of a solution into the subgingival sulcus to approximately 50%.10 Specifically Eackle found that penetration was 71% for shallow (0-3 mm) pockets, 44% for moderate (4-7 mm) pockets, and 68% for deep (>7 mm) pockets.

However, in 60% of deep sites, penetration was 75% or greater.10
The use of a site specific tip on a dental water jet is called
subgingival irrigation. Subgingival irrigation is the intentional, localized delivery to a specific site such as a deep pocket, furcation, implant, or crown and bridge. It is located in the center of Figure 3. The delivery device discussed in this course for this procedure is a soft, flexible rubber tip called the Pik Pocket® subgingival irrigation tip. The Pik Pocket® tip has been demonstrated via a clinical trial to deliver a solution into the pocket up to 90% of its depth in pockets 6 mm or less. For pockets 7 mm or greater, depth of penetration is 64%.11

On the right in Figure 3, you will see a cannula. Although
use of a cannula is sometimes recommended, its safety and efficacy for home use on a dental water jet has not been extensively evaluated. It is important to remember that regardless
of the tip attachment or placement, irrigation with a dental water jet always results in subgingival penetration to control the subgingival microflora and byproducts of the
immuno-inflammatory process.3,4,9,18,19,20,21,22

PRODUCT SAFETY
There are numerous dental water jet devices in today’s marketplace.
The Waterpik® dental water jet has been extensively evaluated for product safety. The more than forty-five studies conducted in twenty-five university and independent research facilities provide a well-documented profile on the safety of the Waterpik® dental water jet.
The more than forty-five studies
conducted in twenty-five university and
independent research facilities provide a
well-documented profile on the safety of
the Waterpik® Dental Water Jet.

Soft Tissue

n a study designed to specifically look at safety for soft tissue, researchers examined untreated, chronic periodontal pockets
immediately following irrigation with the Waterpik® dental water jet. Examination of specimens under a scanning electron microscope showed no observable differences between the irrigated and non-irrigated specimens concerning epithelial topography, cavitations, microulcerations, spatial relationships and individual cell appearance.9 The investigators concluded that the Waterpik® dental water jet is not injurious to soft tissue.
9 This concurs with early work by Krajewski et al who found less inflammation, better connective tissue organization and an increased thickness in the keratin layer in individuals who used a dental water jet twice daily compared to those who did not.23

Gingivitis, Bleeding,
Probing Depth Reductions

Several studies have shown that a dental water jet is extremely effective in reducing gingivitis and bleeding on probing.1-5,20-22,35-40 In many cases, these outcomes were achieved above and beyond routine oral hygiene including flossing.1-5 In a recent study conducted at the University of Nebraska on 105 subjects with at least 50% bleeding sites, a dental water jet was paired with a manual or a power toothbrush and both were compared to traditional manual brushing and flossing to see which regimen
was the most effective. Regardless of brush type, the addition
of a dental water jet, once daily with plain water, to
either a manual or power brushing routine is an effective alternative
to dental floss for the reduction of bleeding, gingivitis, and plaque and in some cases may provide superior results for
reducing bleeding and gingivitis. Additionally, because significant
improvements in oral health occurred regardless of toothbrush type, it is likely that many patients currently using a power toothbrush may get further improvements in oral health by the addition of a dental water jet

Instructions for Using the
Waterpik® Dental Water Jet

When giving instructions for the use of the dental water jet, there are some general suggestions that can make learning how to use the dental water jet an easy and quick process.
For practical purposes, the unit should
not be turned on until the tip is in the mouth.
Bend from the waist over the sink and hold
arm up perpendicular to torso.
Lips should be slightly closed to avoid splashing,
but open enough to allow the water to flow
freely from the mouth into the sink
Befor e removing the tip from the mouth,
pause the flow of water or turn the unit off.
For comfort, recommend that any solution
used is at room temperature.
Advise individuals to begin at the lowest pressure setting when using the dental water jet for the first time. Because there are different types of units available, be sure
to review manufacturer's complete instructions PRIOR to
recommending or demonstrating. Recommending and
instructing is easier if you have read all instructions and
tried the product yourself.