The Interplak Home Plaque Removal Instrument is the next generation in electric toothbrushes. It has the ability to remove 99 percent of plaque, the leading cause of gingivitis and loss of teeth, while it cleans your teeth like a dentist, all in a sleek package no larger than the older model electric toothbrushes and weighing only 18 ounces. The Interplak instrument is a revolutionary design that comes in a small, basic package: (a) the handle, (b) the brush head, and (c) the charging base. (See Figure 1.)
Figure 1. The Interplak Home Plaque Removal Instrument. (All illustrations by Dental Research Corporation, Tucker, GA.)
Handle casing. The casing of the handle actually holds all of the interior electronics in place. It is constructed of white, heat-resistant Cycolac ABS plastic for durability and easy grip.
Note: Heat resistant plastic is used because the handle becomes warm when the batteries are being charged.
The casing measures 1 inch in diameter at its base. The casing remains this diameter for 1 inch to allow the batteries to charge when the instrument is setting in its stand. After this point, the diameter jumps to 1-1/4 inches and gradually increases up to 1-1/2 inches over a length of 6 inches. The size then tapers down to 3/4 inches over a length of 1 inch, making the entire length of the casing 8 inches long. Where the size tapers, one side flattens out to hold the power switch. The numbers 1, 2, and 3 are printed in blue on the casing to indicate the power setting.
Batteries. The internal rechargeable batteries allow the user up to 12 minutes of use without being tied down by a power cord. The two batteries are designed to charge through induction, the ability to charge by just being in the proximity of the electric current, so no part of the batteries is exposed on the outer casing, eliminating the possibility of shock through normal use.
Warning: To receive full charge time, the user must let the toothbrush set in its stand for a minimum of 24 hours.
Figure 2. The Interplak instrument: detailed components
Motor. A small electric motor turns the drive mechanism that moves the brushing gears. It turns one complete revolution 23 times per second. It is connected to the batteries like any other electric motor, having one line attached to the positive battery terminal, and the other line attached to the negative.
Drive mechanism. The drive mechanism actually does the work of getting the motor's action to turn the bristles. It is attached onto the motor with a small plastic disc which measures 3/4 inches in diameter. On the outer edge of this disc, one end of a metal road, measuring 1 inch in length and 1/16 inch in diameter, is attached. The other end of this rod points away from the base of the handle toward the brush head. It enters a small plastic joint where it is attached to another metal rod measuring 2 inches in length and 1/16 inches in diameter. This is connected parallel with the rest of the handle and protrudes 1/2 inches out of the upper end of the handle. The exposed end of this rod has a rib 1/4 inches down where it will eventually be attached to the brush head.
As the motor spins the small plastic disc, the first rod jumps up and down around the disc. When it joins the second rod at the plastic joint, the circular motion is eliminated and a back-and- forth motion is generated as the second rod moves in and out of the end of the handle.
Power switch. The power switch turns the toothbrush on and off, as well as selecting three different speeds. This small, white button is located on the flat tapered portion of the handle casing. It measures 1/2 inches in diameter and features smooth, rounded edges with a recessed blue line on its upper edge to point out the power setting chosen. The power is turned on by pushing the button toward the brush head.
Plastic housing. The plastic housing of the brush head is designed to hold the drive mechanism, gears, and bristles of the toothbrush in a casing. It is formulated to match the color of the handle casing. The housing measures 3-1/2 inches long and its width is 3/4 inches, measuring the same size as the connecting tapered edge of the handle casing. Creating a aerodynamic look, the housing gradually slopes down to 1/4 inches across the face by 3/8 inches deep along a 2-1/4 inches span. The housing then widens and flattens out to 5/8 inches across by 1/4 inches deep to allow room for the bristles. This section is 1-1/4 inches long and is lined by 2 rows of 5 holes measuring 3/32 inches in diameter.
Drive mechanism. The drive mechanism works in conjunction with the drive mechanism from the handle to pulsate the bristles back and forth on the teeth. On the handle end of the mechanism is a yellow rubber boot measuring 1/2 inches long by 1/8 inches in diameter, which locks around the protruding drive shaft of the handle.
Attached to this is a 1 inch long, stainless steel shaft measuring 1/16 inches in diameter. As this shaft enters the bristle chamber, it is attached to a double-sided toothed rod. This rod is 1 inch long by 1/8 inch at the widest margin of the teeth. These teeth are locked with the gears that turn the bristles. Gears. The gears of the toothbrush mesh with the teeth on the drive mechanism, causing the bristles to move in a circle. (See Figure 3.) The 10 gears are toothed circles measuring 3/16 inches in diameter at their widest margin.
Figure 3. The brush head showing bristle direction and gears.
They are located in two rows of 5 on either side of the brush face. There are 3 gears in each row that lock together with the drive mechanism. The other 2 in each row are set away from the others by 1/32 inches toward the outside edge and are driven by the other 3 gears. This arrangement allows 6 gears to move in one direction as 4 spin in the other. As the motor spins the drive disc, this makes the drive mechanism pump back and forth causing the gears to reverse direction 46 times per second. Bristles. The bristles are the soft, plastic fibers that actually come in contact with the teeth and gums. Each set of 10 white bristles is attahed to its own gear by sticking through its hole in the housing and into the center of the gear. The tufts of bristles each extend a maximum of 3/8 inches from their holes and form a point at the ends. The minimum length of the bristles is 1/4 inches. Each tuft is 1/16 inches in diameter.
With the proper techniques, this instrument can lead to healthier teeth and gums provide years of service.
