TECHNICAL TRAINING MODULE

DENTAL CHAIRS SYSTEM

2012

Prepared by

Mohd Nizam Abdullah

Introduction

Dentistry is the branch of medicine that is involved in the study, diagnosis,

prevention, and treatment of diseases, disorders and conditions of the oral cavity,

the maxillofacial area and the adjacent and associated structures, and their

impact on the human body. To the layman, dentistry tends to be perceived as

being focused primarily on human teeth, though it is not limited strictly to this.

Dentistry is widely considered necessary for complete overall health. Doctors

who practice dentistry are known as dentists. The dentist's supporting team –

which includes dental assistants, dental hygienists, dental technicians, and dental

therapists – aids in providing oral health services.

Dentistry usually encompasses very important practices related to the oral cavity.

Oral diseases are major public health problems due to their high incidence and

prevalence across the globe with the disadvantaged affected more than other

socio-economic groups.

The majority of dental treatments are carried out to prevent or treat the two most

common oral diseases which are dental caries (tooth decay) and periodontal

disease (gum disease or pyorrhea). Common treatments involve the restoration of

teeth as a treatment for dental caries (fillings), extraction or surgical removal of teeth

which cannot be restored, scaling of teeth to treat periodontal problems and

endodontic root canal treatment to treat abscessed teeth.

Dental chair system is basically used for oral and orthodontic treatment on the

patients including dental surgery.

History

The Indus Valley Civilization (IVC) has yielded evidence of dentistry being practiced

as far back as 7000 BC. IVC sites in Pakistan indicate that this earliest form of

dentistry involved curing tooth related disorders with bow drills operated, perhaps, by

skilled bead craftsmen. The reconstruction of this ancient form of dentistry showed

that the methods used were reliable and effective.

The first dental foot engine was built by John Greenwood and one of George

Washington’s dentists. It was made from an adapted foot-powered spinning wheel.

The first dental drill was a foot driven instrument invented by John Greenwood in

1790. Far from the high tech dental drills of today, the first dental drill John

Greenwood made was really just a modified version of his mother's foot treadle

spinning wheel. While, a bit unwieldy, it did the trick. In 1957, a dentist named John

Borden invented the high speed contra angle hand piece with 30,000 rotations per

minute, a monumental step forward in dental drilling and polishing.

1790- Was a big year for dentistry, as this was also the year the first specialized

dental chair was invented. It was made from a wooden Windsor chair with a headrest

attached.

In 1790, a prominent American dentist named Josiah Flagg invented the first dentist

chair, complete with headrest and tray for keeping track of implements. In 1832,

inventor James Snell improved on Greenwood's invention by making the chair

recline, making it easier for a dentist to see in his victim's (or patient's) mouth. In

1877, the chair once again made dental headlines when the Wilkerson chair

replaced the Snell chair as the predominant chair type used by dentists.

1840 – The First Dental School is founded

Chapin Harris and Horace Hayden founded the Baltimore College of Dental Surgery,

the first school dedicated solely to dentistry. The college merged with the University

of Maryland School of Dentistry in 1923, which still exists today.

1871-George F. Green invented the first electrical dental engine.

In 1957, John Borden invented the first high speed electric hand drill.

1960s, the first dental lasers are developed and used for soft tissue procedures.

1. Device Application

A dental chair for supporting a patient during examination and the performance of

procedures on the patient includes a patient support having a seat and a back, a

base adapted to engage a floor surface, and a lift arm.

Conventional dental operatories generally include an articulating dental chair for

supporting a patient in a variety of positions to facilitate the performance of dental

procedures and operations. For example, dental chairs are generally adapted to be

raised and lowered relative to a floor surface, and to be moved between a first

orientation where a seat back is inclined relative to a seat base to support the patient

in a seated position, and a second orientation where the seat back is reclined to

support the patient in a generally supine position.

The dental operatory may also include a dental delivery unit adapted to support

various instruments and tools used during the performance of dental procedures.

The delivery unit is typically provided with water and pressurized air for operating the

instruments, and may include a tray for supporting instruments or other articles used

by the practitioner. The delivery unit may be supported on a movable arm that

facilitates positioning the unit and instruments adjacent the dental chair for

convenient access by the practitioner during the performance of a procedure, then

moved away to permit the patient to exit the dental chair when the procedure is

complete.

Conventional dental operatories may further include a cuspidor provided adjacent

the dental chair to permit patients to expel the contents of their mouths during or at

the conclusion of the dental procedure, an adjustably positionable lamphead to

illuminate the treatment area, and various other devices useful for the performance

of dental procedures. Such devices may be supported on cabinetry or other structure

positioned adjacent the dental chair for convenient access by the patient or the

dental practitioner.

A dental chair should generally be movable from a lowered position with the seat

back inclined, which facilitates entry and exit from the chair, and a raised position

with the seat back reclined, which facilitates examination and the performance of

procedures by a dental practitioner. Conventional dental chairs use a lift arm

pivotally coupled to a base at a position intermediate the front and rear ends of the

base to raise and lower the chair. This configuration generally results in a bulky base

structure that has a rather large footprint, making it difficult for a dental practitioner to

navigate around the chair during the performance of procedures. This configuration

also limits the maximum length of the lift arm. In general, a longer lift arm is more

desirable because it provides a greater vertical rise of the chair while minimizing for

and aft movement of the chair during raising and lowering.

Dental chair system is basically, used for oral and orthodontic treatment on the

patients including dental surgery.

The system will consist:-

• Motor controlled mains padded cushion chair;

• Handpiece Delivery System

• Dental Lights

• Monitor mount choices for all mount to rotating arms for greater flexibility

and improved positioning.

• Floor Box

• Cuspidor

• Water System

Motor controlled mains padded cushion chair.

The integral chair-unit is well designed for hi-levels in comfort, safety, quietness and

vibration-free movements, to support the patient and the surgeon at highest

efficiency levels. The latest unit is designed with new technology concepts with no-

compromise to quality of construction, hygiene or performance and ergonomically

designed for use in both two and four hand dentistry.

Easily accessible controls with on-line instrument arm and electronically operated

panel, the unit is complete is every respect and exceptionally flexible in movements.

The all purpose, flexible and moving mechanism just fits-in to your preference of

work position.

Handpiece Delivery System

Handpiece Delivery System is built around a control block for three handpieces and,

in most instances, autoclavable syringe.

Handpiece actuation is automatic. When you lift a handpiece from its holder, the

handpiece becomes active and will run when you press on the foot control disc.

Return the handpiece to its resting position to deactivate it.

Handpiece Controls

Drive Air Pressure Controls

The Drive Air Pressure Controls are used to adjust the drive air pressure to each

handpiece

Coolant Air Flow Control

The coolant air flow control is used to adjust the coolant air flow to all handpieces.

Coolant Water Flow Controls

The coolant water flow controls are used to adjust the flow of coolant water to each

handpiece.

Handpiece Tubing Flush Control

The handpiece tubing flush system flushes more water through the tubings in less

time than is normally possible when operating the foot control only.

Handpiece Dry Block Conversion

The handpiece delivery system has three to four handpiece control blocks with

coolant water to the handpiece. In some cases a control block without coolant water,

a dry block, is required. If you require a dry block (offering no water to the

handpiece) on the handpiece control system, a dry block conversion kit has been

included with your system.

Autoclavable Syringe.

The Autoclavable Syringe is a three-way air and water syringe with a patented quick-

disconnect autoclavable tip system.

The features are:-

Syringe buttons

Syringe tip retainer assembly

Syringe tip

Warm water syringe

Quick disconnect syringe terminal

Syringe Buttons

Autoclavable syringes feature buttons that provide modulated

control of syringe water, air and spray functions.

Quick-Disconnect Syringe Terminal

A quick-disconnect terminal allows a syringe to be removed from the delivery system

without turning the system off.

Operation - Syringe Tip

A-dec designed the syringe tip with three grooves and the syringe tip retainer

assembly with three O-rings to ensure that the syringe performs properly. The first

and second grooves seat two O-rings to prevent tip ejection from the syringe. The

third groove is an indicator of proper installation and is not visible when the tip is

properly installed. The third O-ring prevents water from entering the air tubing in the

syringe tip (see Figure).

Maintenance

All syringe tips are considered critical items and must be heat sterilized between

patients. Remove the syringe and syringe tips from the delivery system for

sterilization. Pre-clean the syringe and tips before sterilization. This prevents the

sterilization process from adhering the accumulated debris onto the syringe and tip.

Pre-clean the syringe and tip

1. Gently brush the syringe threads with a nylon or brass bristle brush.

2. Remove the tip from the syringe.

3. Immerse the tip in a holding solution until ready for ultrasonic cleaning.

4. Clean the tip ultrasonically, following the ultrasonic manufacturer's instructions.

5. Purge all cleaning agents from the syringe and tip before sterilization.

Sterilization

Sterilize the syringe and tip at a maximum temperature of 275°P (135°C).

Sterilize syringes using chemical vapor or steam autoclave at a maximum 275°P

(135°C) for four minutes.

Sterilize syringe tips using dry heat, chemical vapor or steam autoclave at a

maximum 275°P (135°C) for four minutes.

Silicone Lubricant

Use Silicone Lubricant to lubricate the syringe button assemblies and the O-rings

used in the syringe tip retainer assembly. Syringe is designed to be easily serviced.

The syringe parts subject to wear under normal use are provided in a syringe repair

kit which can be ordered from your authorized dealer.

Replacement Parts

As a means of preventive maintenance, it is recommends to replace the two internal

O-rings and the small O-ring in the syringe tip retainer assembly at least once a year.

Lubricate the O-rings with silicone lubricant at the time of replacement.

Troubleshooting

Problem Possible Cause Action

Syringe leaks air or Faulty a-rings on the Replace the button

water from a button button assembly

Syringe tip drips Faulty a-rings on the water Replace the water button

when the syringe is buttons

not in uses

A short burst of Improperly installed or Pull out and reinstall the

water sprays from damaged syringe tip. syringe tip correctly.

the tip when the air Replace the syringe tip if it

button is pressed still leaks

Water or air leaks Syringe handle is not Tighten the syringe handle

from the syringe tightly connected to the onto the syringe

handle syringe

a-rings on the terminal are Replace the a-rings on the

damaged terminal and lubricate with

A-dec silicone lubricant

Air leaks from the Syringe tip is damaged Replace with a new tip.

top of the tip Retainer internal Replace the two inner

retainer assembly a-rings are damaged a-rings of the retainer

assembly

Syringe tip is Retainer internal Replace the a-rings and

difficult to install a-rings have been remove remaining

lubricated with a lubricant from the

petroleum-based lubricant retainer. Use A-dec silicone

lubricant on the new

a-rings

The tip retainer assembly Replace the tip retainer

has been damaged assembly

Water leaks from Tip is not fully installed Push tip completely into

base of tip retainer place with the third groove

assembly hidden

Small a-ring in the retainer Replace the a-ring or

assembly has failed replace the retainer

assembly

Syringe tip is loose A non-A-dec syringe tip is Replace with an

in the retainer in use A-dec syringe tip

assembly Retainer a-rings are worn Replace the a-rings

or damaged

How the Water System Works

Air pressure forces the water from the bottle into the water pick-up tube and out to

various water outputs such as the handpiece control block, syringe, and the cuspidor

cup fill. A self-contained water system is a closed system isolating your chosen

treatment water from the municipal supply

How to Choose Treatment Water

The correct water to use in the self-contained water system (for patient treatment)

depends on the quality of water available from your municipal source and the goals

you have for using the self-contained water system. It is important that whenever

treatment water is specified for a procedure, that you are consistent in your water

source quality.

CUSPIDOR

The cuspidor is equipped with a timer for the bowl rinse. This timer can be adjusted

to increase or decrease the length of time water flows into the bowl. The cuspidor

comes standard with an automatically timed cup fill.

On most units, the cuspidor on/off function is controlled by the master on/off toggle

on the control head. For cuspidor only units, the cuspidor on/off function is controlled

by the on/off toggle on the post box.

Bowl Rinse Button

Contoured Water Spout

Master On/Off Toggle

The master on/off toggle can be found on the post box, control head or Master

Series touch pad. Moving the toggle to the ON position provides air and water to the

system. Move the toggle to the OFF position while the unit is unattended to prevent

water damage in case of a leak.

Cuspidor Limit Switch

To test the cuspidor limit switch, slightly lift the cuspidor and listen for a "click". The

"click" indicates that a switch has been activated. To check the operation of the limit

switch, start lowering the chair. While the chair is in motion, lift the cuspidor slightly.

The chair will stop and all chair functions except Base Up will be disabled. The Base

Up function remains active so you can raise the chair to remove any object caught

under the cuspidor. When the object has been removed, all chair functions will

operate normally.

Gravity Drain Cleaning

At the end of each day, flush the drain to remove debris which can collect in the

flexible drain tubing. If the drain is not flushed regularly, debris may build up and

impair cuspidor draining. To flush the drain, raise the chair to its highest position and

run the bowl rinse several times, long enough so that water flows down the drain for

about 60 seconds.

Cleaning the Cuspidor

The cuspidor is designed for quick and easy cleaning. The contoured spouts and the

smooth cuspidor housing help facilitate more complete cleaning. When cleaning, do

not remove the contoured water spout. Also remember to empty and clean the bowl

screen.

Bowl Rinse Adjustment

The flow of water to rinse the bowl and the length of time that water flows to rinse the

bowl are set at the factory.

The bowl rinse flow adjustment location is inside the post box or under the cuspidor

bowl. To remove the side cover from the post box; insert your fingers under the lower

edge of the cover and pullout and down on the side cover. Loosen the thumbscrew

and lower the cover. Locate the bowl rinse flow adjustment. Notice the position of the

indicator dot which shows the present setting of the flow control. Using an

adjustment key or a 1%a-inch hex key, turn the adjustment key clockwise to increase

the flow rate and counterclockwise to decrease the flow rate. Check the flow rate by

pressing the bowl rinse button. When the adjustment has been completed, reinstall

the cover.

Bowl Rinse Time Adjustment

To change the length of time that water flows for the bowl rinse, locate the time

adjustment screw (see Figure). Use an adjustment key or a 1%a-inch hex key and

turn the adjustment key clockwise (as viewed from the bottom) to increase the length

of time water flows to rinse the bowl or counterclockwise to decrease the length of

time. Check the length of time for water flow and adjust until it is satisfactory.

Timed or Manual Cup Fill

The timer for the automatic cup fill is set at the factory. If you ordered an optional

manual cup fill, the water flow is set during installation to prevent splashing. In either

case, the amount of water flowing into the cup may be changed.

If an adjustment is necessary to either the manual or timed cup fill, remove the side

cover on the post box by inserting your fingers under the lower edge of the cover and

pulling out and down on the cover, loosen the thumbscrew and lower the cover.

Locate the cup fiII flow adjustment. Notice the location of the indicator dot showing

the position of the current setting. Use an adjustment key or a hex key and turn the

key clockwise to increase the flow rate or counterclockwise to decrease the flow rate.

Check the cup fill flow. When the adjustment has been completed, reinstall the

cover.

Adjustment screw

Dental Lights

The dental light has balanced lighting to give you a clear view of tooth surfaces, the

precision-balanced arm allows for smooth positioning, and the light's diagonal axis

lets you angle the light head.

The light is equipped with a large On/Off toggle and On/Off control is also located on

the touchpad. There are three intensity settings which you can choose from high,

medium or composite settings by moving the intensity switch located on the back of

the switch housing. A quick press on the Light button on the touchpad allows you to

toggle between intensity settings, depending on the location of the dental light's

intensity switch.

Operation

The dental light includes a number of features designed to make your job easier. The

balanced light gives a clear view of tooth surfaces, the precision-balanced arm

allows for smooth positioning, and the light's diagonal axis lets you angle the light

head just where you need it.

The dental light also has an Auto On/Off feature. When the chair reaches an

operating position, the dental light will turn on. When the chair moves out of the

operating position, the dental light turns off. The auto on/ off setting can be turned off

by pressing and holding the Program button and then the Light button together for

three seconds. One beep will confirm that the factory preset has been turned off. To

return to the factory preset, repeat steps. Three beeps will confirm that the auto

on/off function is on.

A - Intensity switch; B - On/Off switch

How to Adjust the Dental Light

The light is adjusted at for proper illumination at 27 inches (700 mm) from the oral

cavity. However, you can quickly and easily adjust the light focus (between 18 and

31 inches [460 mm and 790 mm]) to best suit your needs.

How to Focus the Light

1. Place a white towel over the chair headrest to represent the oral cavity.

2. Position the light head at the distance you would normally use it when

working in the oral cavity (select a distance representative of most of your

work).

3. Turn the light ON.

4. Use a large screwdriver or coin to turn the focus adjusting screw until the light

within the borders of the light pattern is most uniform.

FLOOR BOXES

The recessed or stainless steel floor box is mounted over the utilities on the floor or

wall of the clinic. Located in the floor box are the air and water manual shutoff

valves, filters, and pressure pre-regulators. You will find vacuum or gravity drains as

well as electrical outlets. The stainless steel floor box covers lift off for access to the

utilities and optional power supplies and/or water heater.

Floor Box Controls and Functions

The stainless steel floor box covers lift off for access to the utilities and optional

power supplies and/or water heater.

To remove the cover from your Cascade Floor Box, slide the cover forward a little

and lift.

The recessed floor box cover is held in place by four screws. Removing the screws

will allow you to lift the cover.

Note

Do not use saline solution, mouth rinses, or any chemical solutions not specified in

the manual in your municipal water supply. These may damage the water system

components and cause the failure of your dental unit. As a general rule, water that is

suitable for drinking is suitable to use in your delivery system.

FiIter Maintenance

Air and Water Filter Elements

Air and water pass through separate filters before entering the regulators. A filter

must be replaced when it becomes sufficiently clogged causing restricted flow to the

regulator.

Water temperature control

(tank Type Water heater) Pre regulator

Filter

Water manual shutoff valve

Air actuated water shutoff valve

Checking for a Clogged Air Filter

To check for a clogged air filter, flip the master onoff toggle to the ON position and

remove the floor box cover. While watching the air pressure gauge in the floor box,

press the syringe air button. If the air pressure indicated by the gauge drops by more

than 15 psi, the fiIter element is clogged and must be replaced.

Checking for a Clogged Water Filter

To check for a clogged water filter, flip the master on-off toggle on the control head

to the ON position, then remove the floor box cover. Watch the water gauge, press

the syringe water button. If the water pressure drops by more than 10 psi, the water

filter is clogged and must be replaced.

To inspect or replace a filter element, flip the master on-off toggle to the OFF

position, then close the manual shutoff valves. Bleed the system of air and water

pressure by operating the syringe buttons until air and water no longer flow. Using a

standard (flat-blade) screwdriver, remove the filter housing from the air and/or water

pre-regulators assemblies (see Figure) and remove the filter. If the filter is visibly

clogged or discolored, you will need to replace it.

When installing a new filter, notice that one end of the filter has a beveled edge.

Install the filter with the beveled edge facing the manifold (see Figure). The system

will not work properly if the filter is installed incorrectly.

Planned Preventive Maintenance

Filter Housing

O Ring

Filter Element

Beveled Edge

PPM consists of the following:-

1. Qualitative Tasks

2. Preventive Maintenance Tasks

3. Quantitative Tasks

4. Electrical Safety Test

Qualitative Tasks

Indicators/Displays – verify proper illumination and operation.

Valves/Solenoids – verify integrity and operation.

Tubes/Hoses – verify conditions.

Incoming Air Pressure – verify availability.

Incoming Water Supply – verify availability.

Filters – verify condition.

Labeling - verify presence and placement of all labels, placards, instructions

cards etc.

Accessories – verify availability.

Preventive Maintenance Tasks

1. Clean Exterior.

2. Inspect/Clean Interior of unit.

3. Lubricate recommended parts and areas.

4. Filters – change if necessary.

5. Water Supply Line – Clean/de-scale if necessary.

6. Air and Water Traps – Flash clean, replace O ring seal if necessary.

7. Oil Level – Inspect and check level, top up if necessary.

8. Align/Adjust Electrical Components.

9. Align/Adjust Mechanical Components.

Quantitative Tasks

1. Incoming Water Pressure

2. Incoming Air Pressure

3. Vacuum Pressure

Test Equipment

1. Electrical Safety Test

2. Pressure Test Gauges/ Vacuum Gauge.

Above information is a general guide to better understanding of the Dental

Chair System. For further detail information, please refer to Manufacturer’s

Operation/Service manuals.