This document outlines the development of a new saliva ejector product called Mr. ThirstyTM. It begins with an introduction to saliva ejectors and their uses in dental procedures. It then presents the project plan, which includes establishing an organizational structure, defining objectives and timelines. Next, it discusses identifying customer needs through interviews and observations. It also establishes target specifications based on customer needs and establishes a concept generation process. The document outlines the full planned development process for Mr. ThirstyTM from concept generation through testing and production. The overall goal is to develop an improved saliva ejector that boosts dental procedures, improves the patient experience, and has minimal costs and energy usage.

1. 1
University of
Malaya
KMEM 2218
Product Design & Development
Mr. Thirsty™: A Saliva Ejector
An Application to Boost Dentists’ Daily Mission Worldwide
Instructor of the group design project
Dr. Mohd Faizul Bin Mohd Sabri
MUHAMMAD SYARAFFI BIN SHAARANI KEM 100040
TAN KIM GUAN KEM 100052
LEE CHIA CHUN KEM 100017
MOHD EDZADZUL BIN MOHD NOOR KEM 100029

2. 2
Executive Summary
It is a well-established physiological fact that any time something foreign is introduced into a
person’s mouth, the salivary glands kick into overdrive, producing considerable amounts of
saliva. For the dentist or orthodontist, this presents not only an inconvenient distraction and
functional obstacle, but a potential compromise in both patient comfort and safety. If the
saliva is allowed to accumulate, the dentist or technician’s ability to see is compromised,
potentially to the point of compromising the ability to continue with the procedure. The
patient’s natural response is to swallow, which not only interrupts the clinician’s efforts, but
poses a health risk to the patient due to the ingestion of any debris that might exist in the
saliva. It can even put the dentist or technician at risk. And at the very least, the pooling of
saliva inside the patient’s mouth adds significantly to the patient’s discomfort and stress.
All of these distracting and potentially harmful results are effectively eliminated by the use of
Mr. Thirsty™, the dental saliva ejector, which is designed in such a way as to eliminate or
minimize several undesirable effects. First and foremost, Mr. Thirsty™ is efficient in the
removal of not only saliva, but blood and debris generated during the procedure, so that
the dentist has clear visibility of the area being treated. Next, it allows flexible movement of
the parts and the tip of the saliva ejector, thus contributes to the patient comfort. Mr.
Thirsty™ is specially made to maintain the required position, while not forcing the
patient’s mouth into assuming a more uncomfortable position than absolutely necessary for
the procedure. Mr. Thirsty™ is also shaped and fabricated from materials that allow
sufficient flow, while minimizing tissue impingement and the ensuing discomfort. The tip of
Mr. Thirsty™ saliva ejector can be disconnected from the actual tubing for sterilization.
This leads to another function of this product that is Mr. Thirsty™ comes with disinfectant
as well to eliminate the bacterial. The many fine tubing (with antibacterial biofilm coated
at the inner part of the tubing) of Mr. Thirsty™ facilitates the vacuuming process inside the
oral cavity too. Besides, it has the ability to eliminate bad odour of the patient’s mouth.
Dentists no longer need to be afraid of the bad mouth odour. Other sided features like mirror
and torchlight serve to facilitate dental procedures. Overall, Mr. Thirsty™ is a light weight,
quiet machine and portable, cost-effective as well.
The main key features of Mr. Thirsty™ are in bold which aims at differentiating itself from
the rest of the similar existing products in the market place. The project team wants to
address the customers’ needs and demands and meet their expectations as well as to assist
dentists in performing daily mission. This design project, guided by our respected instructor,
Dr. , will be a stepping stone for us to initiate the production and development of this product,
the highly energy-efficient, user-friendly and cost effective saliva ejector. We try to
differentiate our design based on the five Perceived Qualities: Tangibility, Reliability,
Assurance, Empathy and Responsiveness.

3. 3
Table of Contents
Development Processes................................................................................................................ 6
&................................................................................................................................................. 6
Organizations............................................................................................................................... 6
1.0 Introduction.................................................................................................................. 7
1.0.1 Parts of the Saliva Ejectors...................................................................................... 8
1.0.2 Whenit is Used?.....................................................................................................8
1.1 Flow of Report............................................................................................................... 8
1.2 Organizational Chart......................................................................................................9
1.3 Terms of Reference........................................................................................................9
1.4 Milestones(Gantt-Chart).............................................................................................. 10
1.5 Mission Statement....................................................................................................... 11
Product Planning........................................................................................................................ 13
2.0 Types of Product Development Projects........................................................................ 14
2.1 The Process................................................................................................................. 14
Identify Opportunity ............................................................................................................... 14
Demand for Saliva Ejector.................................................................................................... 14
Problems Statement of Existing Saliva Ejector....................................................................... 14
Interview............................................................................................................................ 15
Opportunity statement........................................................................................................ 15
Evaluate & Prioritize Projects................................................................................................... 15
Market Segmentation:......................................................................................................... 15
Allocate Resources.................................................................................................................. 15
Complete Pre-Project Planning................................................................................................ 16
Graph of Capacity Utilization v.s Time (month).........................................................................
Reflect ................................................................................................................................... 17
Identifying Customer Needs........................................................................................................ 18
3.0 Identifying Customers’Needs....................................................................................... 19
3.1 Gather Raw Data from Customers................................................................................. 19
3.1.1 Interview ............................................................................................................. 19
3.1.2 Observing the Productin Use................................................................................ 19
3.1.3 Telephonic Interview ............................................................................................ 20
3.1.4 Choosing Customers............................................................................................. 20
3.2 Interpret Raw Data in Terms of Customer Needs ........................................................... 20
3.3 Organize the Needs into Hierarchy................................................................................ 21
3.4 Establish the Relative Importance of the Needs............................................................. 22

4. 4
Product Specification.................................................................................................................. 23
4.0 The Relative Importance and Customer’s Needs............................................................ 24
4.1 Establishing Target Specifications ................................................................................. 24
4.1.1 Prepare the List of Metrics.................................................................................... 24
Table 7: Customer-Need Matrix Chart......................................................................................
4.1.1 Competitive Benchmarking Information................................................................. 26
Concept Generation.................................................................................................................... 29
5.0 Problems and Solutions................................................................................................ 30
5.1 Our Initial Concepts and Challenges Faced..................................................................... 31
5.0 Concept –Scoring Matrix .............................................................................................. 33
Concept Selected.................................................................................................................... 34
Concept Testing.......................................................................................................................... 35
6.1 Define the Purpose of the Concept Testing.................................................................... 36
6.2 Choose a Survey Population ......................................................................................... 36
6.3 Choose a Survey Format............................................................................................... 36
6.4 Communicate the Concept........................................................................................... 36
6.5 Measure Customer Response....................................................................................... 36
6.6 Interpret the Results.................................................................................................... 37
Results....................................................................................................................................... 38
7.0 Modeling..................................................................................................................... 39
7.1 Technical Drawings...................................................................................................... 47
7.2 Analysis....................................................................................................................... 67
7.3 Materials Selection ...................................................................................................... 70
7.4 Manufacturing Process................................................................................................. 71
7.5 Cost Estimation............................................................................................................ 71
Standard Components......................................................................................................... 71
Custom Components........................................................................................................... 71
Add on Costs:...................................................................................................................... 73
Add on................................................................................................................................ 73
Tetracycline antibiotics ............................................................................................................... 73
Tetracycline ........................................................................................................................ 73
0.03.................................................................................................................................... 73
1423.00 .............................................................................................................................. 73
42.69 .................................................................................................................................. 73
Total add on cost :............................................................................................................... 73
42.69 .................................................................................................................................. 73

5. 5
7.6 Cost-to-produce........................................................................................................... 73
Summary ................................................................................................................................... 74
Conclusions and Recommendations............................................................................................. 75
Reference .................................................................................................................................. 75
APPENDIX .................................................................................................................................. 76
Appendix A: Interview Questions and Answers......................................................................... 76
Appendix B: Phone Interview Guide for Concept Test of the Saliva Ejector................................. 79

6. 6
Development
Processes
&
Organizations
-Introduction
-Organizational Chart
-Terms of Reference
-Milestones
-Mission Statement

7. 7
1.0 Introduction
Based on the definition of saliva ejector found in “The Free Medical Dictionary”, saliva
ejector is a device (containing a removable tip) that is attached to a vacuum supply to remove
saliva from a dental field of operation. The saliva ejector is the low volume evacuation
system. It is a flexible, plastic tube about one-third the size of the high volume evacuation
tube. The saliva ejector is bent and then positioned between the tongue and the mandibular
teeth r between the cheek and the mandibular teeth. A saliva ejector is a device, often used by
dentists, which generally consists of a suction tube and a disposable tip. It is typically
inserted into a patient’s mouth to remove saliva as well as blood and other waste materials.
Usually made of plastic, the device can include a flexible wire to bend it into a hook shape
so that it can be inserted comfortably.
Plastic or recycled materials can be used to manufacture a saliva ejector. There are various
models, and some include extra components such as a tongue retractor for use when a dentist
needs more room to work in the mouth. Extra space often comes in handy during complex
procedures in which other dental equipment is used as well. Accessories such as specialized
sponges can be fit onto the edge of the device if a patient is uncomfortable, to provide some
cushioning. Other devices are padded, which often allows them to be used as cheek retractors
as well.
Saliva ejectors are sometimes available in coiled designs with several small holes. These can
often be bent into a shape that fits the floor of the mouth. Other devices can be disposable.
Some are compatible with mirror attachments with small hollow handles; fluids typically
travel through these to the main suction tube. These accessories are often more suited for
devices that operate at slow speeds.
High-speed systems are generally used when there is an assistant present. They are typically
longer and heavier that other models. A saliva ejector that operates this way may have a
rotating swivel and adjustable length. One type can actually serve different roles during a
dental procedure and includes a light for use inside the mouth.
In some cases, fluids from a saliva ejector can flow backward. If one closes his or her lips
around the device, this can create a seal that lowers the pressure in one’s mouth, causing the
fluids to reverse direction. Research has not found any significant health concerns associated
with this phenomenon. Some scientists, however, advise that dentists not tell patients to close
their mouth when using a saliva ejector. The device should also be hung below the patient
and proper disinfection procedures should be followed in between treatments.

8. 8
1.0.1 Parts of the Saliva Ejectors
1. Plastic tube or a metal “shepherd’s hook” tube-The plastic tube is the most common,
although the stainless-steel tubes are available. The plastic saliva ejector is less expensive and
is disposable. The end that is placed in the patient’s mouth has a guard cover to prevent large
particles of debris from becoming lodged in the tube.
2. Handle-The plastic tube is inserted in the handle which is connected to the hose. The
handle has an on/off control and also a small screen that acts as a filter, located near the tube
end of the handle.
3. Hose-The hose end attaches to a low volume vacuum source in the unit.
1.0.2 When it is Used?
The saliva ejector is used during procedures that do not require removal of large amounts of
fluids, such as during fluoride treatment, under the rubber dam, or during a coronal polish.
Sometimes the saliva ejector is used for brief periods of time, or it can be left in place during
a procedure such as a dental cleaning, tooth filling, or a root canal, for example.
1.1 Flow of Report
The purpose of developing the product, Mr. Thirsty™, the dental saliva ejector, is to meet
the requirement of the daily dental operation and also the demand of the patients. The
development process is generic and also quick-built product used in a market-pull situation.
Our team begins with a market opportunity and selects appropriate technologies to meet
customers’ needs. In addition, we use 3D computer-aided design models, known as
SolidWorks™, to construct digital prototype that resembles the actual saliva ejector.
Phase 0: Phase 1: Phase 2: Phase 3: Phase 4: Phase 5:
Planning Concept
Developmen
t
System-
Level
Design
Detail
Design
Testing and
Refinement
Production
Ramp-Up
Phase 0: Planning:
 We get started in the beginning of March 2012
 We were requested to define our products to be produced by looking around in the
labs in the Faculty of Engineering
 We define our product, which is the saliva ejector. We named it as Mr. Thirsty™
 We define our mission statement, team organization and terms of reference (TOR)
 We define our work plans and milestone
 Define market segments and articulate market opportunity

9. 9
Leader
Syaraffi
Design
Tan Kim Guan
Lee Chia Chun
Electrical
Wiring
Edzadzul
1.2 OrganizationalChart
1.3 Terms of Reference
Name Role
Syaraffi -Acts as the team leader of the design project
-Ensure everyone is doing the works according to the timeline
-Call for team meeting
-Motivate members
-Lead a discussion and draw conclusions
Edzadzul -Responsible in designing the electrical board
-Ensure the energy consumption of the product is at its lowest energy possible
-Ensure the product complies to energy-saving protocol
Lee Chia Chun (Max) -Coordinator for designing efforts
-Perform competitive benchmarking and economic analysis on the product
-Collect customers’ feedback and conduct interview
-Prepare the report
Tan Kim Guan -Coordinator for designing efforts
-Perform safety factor analysis and testing on the product
Type of Organizational Link we used:
Reporting Relationship
Explanation: We report to the team leader
on a weekly basis through Facebook

10. 10
1.4 Milestones (Gantt-Chart)
Time
Tasks
Feb Mar Apr May
20–26
27–4
5–11
12–18
19–25
26-1
2–8
9–15
16–22
23–29
30–6
7–13
14-20
21-27
Surveying lab equipments 
Brainstorming  
Planning
-Task Division
-Terms of Reference
-Identify Customers’ Needs



Establishing Target Specifications  
Generate Product Concept
-Benchmarking
-Concept
 
Select Product Concepts
-Concept Rating
-Concept Ranking
-Combine and ImproveConcepts
 
Product Testing
-Asking customers’ opinion
  
Finalization
-Set final specifications
-Plan downstream development
-Report Writing
   

11. 11
1.5 MissionStatement
We want to boost dentists’ daily dental procedures worldwide, as well as giving the patients
the best satisfaction when receiving treatment from dentist. We focus on innovating saliva
ejector which boost dental procedures and gives patients the positive dental experience at
minimal manufacturing cost and energy consumption (environment-friendly).
Mission Statement: Saliva Ejector (Mr. ThirstyTM) Dental Equipment
Product Description Portable, light-weight, cost-effective,
energy-efficient, user-friendly, safe-to-
use and has micro-camera to record the
dental treatment processes for
educational purposes
Benefit Proposition  Multiple functions in one portable,
energy-efficient device
 Support educational works by
recording the dental treatment
processes while serving its main
purpose to boost patients’ dental
treatment experience
Key Business Goals  Serve as a platform for all future
dental equipment products and
solutions
Primary Market  Dental hygienists or dentists
 Patients (users)
Secondary Market  Public hospitals
Assumptions and Constraints  Multiple functions such as mirror, mini
torchlight and micro-camera could be
installed
 Disposable versus reuse
Stakeholders  Purchasers and users
 Manufacturing operations
 Service operations
 Distributors and retailers
 Logistics partner (DHL)
Phase 1: Concept Development
 Collect customer needs
 Identify lead users
 Identify competitive products
 Build and test experimental prototypes
 Estimating manufacturing costs
Phase 2: System-Level Design
 Identify suppliers, compare the prices of the material and draw a budget
 Define final assembly
Phase 3: Detail Design

12. 12
 Define part geometry
 Choose materials (for economical purpose)
Phase 4: Testing and Refinement
 Conduct performance and reliability testing
 Implement design changes (if necessary)
 Refine fabrication and assembly processes
 Obtain patents
Phase 5: Production Ramp-Up
 Submit the report to the lecturer for checking and evaluation
Format used in the following contents of our design report would be in accordance with the
diagram shown below:
Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7
Identifying
customer
needs
Establishing
target
specifications
Generate
product
concepts
Select
product
concepts
Test
product
concepts
Set final
specifications
Get Patent
Submit report to the
instructor for evaluation
Furthermore, there are three things that involve on the whole process:
1. Economic analysis
2. Benchmarking of competitive products
3. Modelling and prototyping
In the next section, before we illustrate the details for each step taken above, we shall present
another quintessentially crucial topic which is the Product Planning.

13. 13
Product Planning
-Types of Product Development Project
-The Product Development Process

14. 14
Identify
Oppor.
Evaluate&
Prioritize
Projects
Allocate
Resources
Complete
Pre-project
planning
Reflect
2.0 Types of Product DevelopmentProjects
In our project, we choose the derivatives of existing product platforms as the type of product
development project to Mr. Thirsty™.
2.1 The Process
To develop a product plan and project mission statement, our team follows the five-step
process:
1. Identify opportunities
2. Evaluate and prioritize projects
3. Allocate resources and plan timing
4. Complete pre-project planning
5. Reflect on the results and the process
Identify Opportunity
Demand for Saliva Ejector
(i) Exploring from the Implications of Trends in Lifestyles & Demography
The intake of fast food is increasing worldwide. In 1970, there were about 30,000 fast-food
restaurants in the United States; that number increased to 222,000 by 2001. This growing
trend is concerning as many health consequences come along with a diet full of fast food.
More than 50,000,000 people in U.S. depend on fast food. Americans alone spend over 110
billion dollars for different types of fast food that is over a quarter of Americans. The
settlement of many large fast food multinational companies has invariantly brought up dental
diseases. Thus, the demand for more dental equipments would increase. One of the most
required dental equipments to perform dental daily mission is the saliva ejector. This is
part of the reason our team wants to improve the saliva ejector.
(ii) Exploring from the Increasing Trend of Dental Implants for Attractive Smile
Severe gum disease and tooth loss are more common today than one would think. In fact,
there are hundreds of millions of people throughout the world who are missing one or more
teeth and over 40 million fully edentulous people in the Western developed world. For this
reason, dental implants are becoming a more popular and commonly accepted treatment plan
to restore a healthy, beautiful smile. For over 40 years, dental implants have been accepted by
dental professionals as a successful and trusted method of tooth replacement.
Problems Statement of Existing Saliva Ejector
Before we venture into innovating the existing the saliva ejector, our team want to identify
thus tackle the fundamental problems found in the existing product. This is also to show that

15. 15
Identify
Oppor.
Evaluate &
Prioritize
Projects
Allocate
Resources
Complete
Pre-project
planning
Reflect
Identify
Oppor.
Evaluate&
Prioritize
Projects
Allocate
Resources
Complete
Pre-project
planning
Reflect
we have carefully studied competitors’ products on an ongoing basis. The list below is
also serves to document practitioners’ and customers’ frustrations and complaints while
using the existing saliva ejector.
 Backflow caused by the pressure differentials in evacuation system tubing
 Noise produced by the saliva ejector machine
 Energy wastage
 Saliva ejector tip keeps falling off
 Saliva ejectors are single-use items and must be disposed of after a single use
 Patients who close their lips tightly around the tip of the saliva ejector would cause
backflow of the suctioned fluids (contains bloods, saliva, bacterial and debris like
amalgam)
Interview
Refer to Appendix A and B
Opportunity statement
 Create a more flexible
 Convenient
 Cheaper
 Comfort
Evaluate & Prioritize Projects
Our team embraces step 2, which is Evaluate & Prioritize Projects because we want to focus
on certain opportunities collected from the step 1 process. Our team has decided to apply
MarketSegmentation:
Our focused groups of consumers are:
i. Dentist / Dental hygienist
ii. Dental patients
Dentists are generally looking for saliva ejector that is light, easy to clean and manage,
portable if possible, cost-effective, energy efficient and easy to install/set up.
Dental patients are looking for saliva ejector that improves compatibility and ergonomic,
user-friendly and safe to use and finally produce less noises.
Allocate Resources
The resources of creating the saliva ejector are as below:
i. Four design teammates

16. 16
Identify
Oppor.
Evaluate&
Prioritize
Projects
Allocate
Resources
Complete
Pre-project
planning
Reflect
0
20
40
60
80
100
120
March April May
Mechanical Design
Electrical Design
Software
Graph of Capacity Utilization v.s Time (month)
ii. Rapid Prototyping Softwares such as AutoCad, SolidWork etc
iii. Wireless Fidelity/Internet
iv. Professional dentist/academicians and patients
v. Books/Websites
vi. 3 months duration for preparation
Complete Pre-ProjectPlanning
The

17. 17
Identify
Oppor.
Evaluate&
Prioritize
Projects
Allocate
Resources
Complete
Pre-project
planning
Reflect
Reflect
Our team reflected at the last stage of product planning by asking several important questions:
1. How can we ensure our product created is well-accepted by the users and patients?
2. How can we ensure that the product that we are designing is in line with the core purpose?
Eventually, our team come up with the mission statement. It is the handoff to the
development team; a “reality check” must be performed before proceeding with the
development process. Our team constantly reflect to stay on the right tract while devising the
saliva ejector.

18. 18
Identifying
Customer Needs
-Gather Raw Data: Interview Lead Users
-Interpretation of Customers’ Needs
- Organizing the Needs into Hierarchy
-Establishing Relative Importance of the Needs
-Reflect on the Results

19. 19
3.0 Identifying Customers’Needs
We invested much time on identifying customers’ needs as it is an integral part of the
development processes and is most closely related to concept generation, concept selection,
competitive benchmarking and the establishment of product specifications.
Concept Development- Front-end process
Identify
Customer
Needs
Establish
Target
Specifications
Generate
Product
Concepts
Select
Product
Concept
Test
Product
Concept
Set Final
Specifications
Plan
Downstream
Development
Perform Financial Analysis
Benchmarking Competitive Products
Build and Test Models and Prototypes
Exhibit 4-2 the customer-needs activity in relation to other concept development activities
Our team follows the process of identifying customer needs that includes five steps:
1. Gather raw data from customers
2. Interpret the raw data in terms of customer needs
3. Organize the Needs into Hierarchy
4. Establishing the Relative Importance of the Needs
5. Reflect on the Results and the Process
3.1 Gather Raw Data from Customers
Our team employed the following methods to gather raw data from customers:
1. Face-to-face interview
2. Telephonic interview
3. Observing the product in use
3.1.1 Interview
Our team employed the interview method to obtain as many data as possible from both dental
patients and dentists/dental hygienists. We collected a total of nine customers’ responses,
each of the interview lasted for 10 minutes at most as the dental patients are in a hurry.
Our team specifically went to the Faculty of Dentistry to arrange an appointment with a
Dental Lecturer, Dr. Eshamsul Bin Sulaiman,from the Department of Conservative
Dentistry. Please refer to Appendix A for details.
3.1.2 Observing the Product in Use
As some of us made the visit to the Medical Centre in University of Malaya, we manage to
observe how saliva ejector was deployed throughout the dental procedures. Our team did not
take any photo as a sign of respect to the patients and
also not to disturb the dentist who was performing their
duties. We will be using images found in Google search
result to approximate the photo that could at best
describe our experiences.

20. 20
We realized that the customers or rather the patients detest the drilling sound and gravelly
sound produced by the saliva ejector. The undesired noises produced increases their fear for
dental treatment. This was observed when the patients looked uneasy with the saliva ejector
placing inside the mouth. Further findings will be tabulated in the next section namely
“Interpret Raw Data in Terms of Customer Needs”.
3.1.3 Telephonic Interview
Our team bought some i-talk card valued RM10 to call up to interview five regular patients.
We get the contacts from friends who receive treatment. Their age groups can be categorized
into 15 – 19 years old group (1 person), 20 – 29 years old group (3 persons) and 30 – 40 years
old group (1 person) of people. Please refer to Appendix B to read up the actual conversation.
The outcomes of the telephonic interview will be revealed in the next section namely
“Interpret Raw Data in Terms of Customer Needs”.
3.1.4 Choosing Customers
Lead Users Users
Dental Patients
(occasional use)
0 5
Dental Hygienists
(frequent use)
3 -
Dentists
(heavy-duty-use)
2 -
Table: Customer selection matrix for the dental saliva ejector
3.2 Interpret Raw Data in Terms of Customer Needs
The customer needs are expressed in written statements and are the results of interpreting the
need underlying the raw data gathered from the above three methods, namely face-to-face
interview, telephonic interview and observation. Each statement or observation may be
translated into any number of customer needs. Below is just one out of the five dental patients’
responses through telephonic interview.
Customer: Karugan Alias Sophilia Interviewer: Lee Chia Chun
Address : 82-A Asabin Villas Date : 8th March 2012
179-1, Jalan Lancang
Taman Sri Bahtera,
56100 Kuala Lumpur
Telephone: 03-9132 1922 Currently uses: Comfort Plus™ Premium SE
Willing to do follow up? Yes Type of user: Patient
Question/Prompt Customer Statement Interpreted Need
Typical uses I sometimes do feel the
backflow of the waste back to
The SE should be placed higher fro the

21. 21
my mouth during the dental
procedure.
Econ
I am afraid of the bacterial
infection.
The SE should have antibacterial
biofilm at the inner lining of the tube
Like-current tool I like how the saliva ejector
maintains the moisture level
inside my mouth.
The SE has high level of vacuuming
ability.
I am comfortable using it. The SE should be made of light material
and can be bent easily and stay firmed at
the required position or posture.
Dislike- current tool I do not like the noise produced
by the suctioning process of the
saliva ejector.
The SE should produce less noise by
suctioning periodically and has a more
efficient compressor to perform its task.
I wish that the tip won’t fall off
so easily.
The tip of the SE should be held tighter
and firmer without falling off.
Suggested Improvement A valve to prevent backflow. The SE should install valve at the end of
the tubing to prevent backflow of
debris, saliva and bacterial.
Would be nice if the tubing can
be spread inside the mouth.
The tubing of SE should be spread into
different branches to boost suctioning
speed.
Table 4: Customer data template (SE is an abbreviation of Saliva Ejector)
3.3 Organize the Needs into Hierarchy
The SE has high suctioning ability Environmental Impact
* The SE maintains power for several hours of
heavy use.
*** The SE must be able to operate at lowest
energy possible.
** The SE has branching of tubes to facilitate
suctioning processes.
**! The tip of the SE must be able to be
recycled.
*** The SE has valve to prevent backflow, thus
improve suctioning ability.
** The suctioned hazardous materials such as
amalgam must be handled with
circumspection.
The SE comes with a portable dental unit The SE is ergonomic
**! The SE is portable, light and energy-saving.
* The SE can serve various functions such as
mirror, torchlight
The SE must occupy smallest area possible.
The SE must safe to use
*** The SE must have disinfectant to clear its tip.
** The SE must be made of biocompatible
materials.
Table 5: Hierarchical list of primary and secondary customer needs forthe saliva ejector. Importance
ratings forthe secondary needs are indicated by the number of *’s,with *** denoting critically
important needs. Latent needs are denoted by !.

22. 22
3.4 Establishthe Relative Importance of the Needs
Customer Need Relative Importance
Most Important Least Important
1 2 3 4 5
High suctioning ability
Environmental friendly
Low energy consumption
Biocompatible materials
Has a proper waste treatment system
Cost-effective
Light weight
Portable
Attractive colour
Flexibility of the tubings
Inner wall of the tubing is coated with antibacterial
bio-film
Branching of the tubing
Has a tongue retractor
Ergonomic
Valve installed at the end of the tips
Disinfectant container installed to hold the saliva
ejector when not in use
Moisture level is maintained at the level suitable for
dental procedures to take place
Other features such as mirror, torchlight etc
Ability to eliminate smell (Halitosis)
Table 6: The relative importance (by customers’perception) of each feature which is to be included
into the designing of Mr. ThirstyTM
.

23. 23
Product
Specification
-Customers’ Need and Relative Importance
-Establishing Target Specifications (four-step process)
-Setting Final Specifications (five-step process)

24. 24
4.0 The Relative Importance and Customer’s Needs
No. Features Need Imp.
1 Wheel To allow mobility from one place to
another
1
2 Disinfectant container To kill bacterial after inserting the tip of
the saliva ejector into a patient’s mouth
1
3 Stopper To stop when necessarily 3
4 Composite material tubing with bio-film
lining
To eliminate bacterial 1
5 Valves To prevent backflow of the saliva, debris
and amalgam wastes
1
6 Compressor To provide power to suck the saliva from
the mouth
1
7 Power cord To supply input electrical energy 1
8 Waste tank To store hazardous wastes such as
amalgam
4
9 Mirror To ease dental procedures 2
10 Torchlight To ease dental procedures 2
11 Casing Attractive casing for aesthetic purpose 2
12 Low energy consumption Can save on electricity bill list 3
13 Easy to install Dentists are not expert in setting up 2
14 Eliminate smell To ease dentist to work 5
15 Occupy small space Dental clinic has a limited space 2
16 Cost Affordable by dentists 4
17 Ergonomic Design for ease of handling 3
Table 7: Relative importance of the feature in corresponding to customers’ needs
4.1 Establishing TargetSpecifications
A product design specification (PDS) is a statement of what a not-yet-designed product is
intended to do. Its aim is to ensure that the subsequent design and development of a product
meets the needs of the user. As our team puts effort in producing the design of the saliva
ejector, we applied the four-step process step:
1. Prepare the list of metrics
2. Collect competitive benchmarking information
3. Set ideal and marginally accepted target values
4. Reflect on the results and the process
4.1.1 Prepare the List of Metrics
See the table below that features the needs-metrics matrix

25. 25
1
2
3
4
5
6
7
8
9
10
11
12
13
Metric
Wheelwithstopper
Attenuationofnoiselevelbelow
40Hz
Tubingmadeoffibre-opticslike
compositematerials
Thetipandbodyofthetubingis
madeofrubber
Innerwallofthetubingiscoated
withtetracyclineBio-film
20cmindiameterexpandable
wastebag
Suctionflowrateof28lpm
1/10HPmotor,115V60Hz
Hasmultipleholesfoundalong
thetubing
StressStraintestonthewheel
Bendingstrength(onthewheeland
thetipoftheejector)
Fulfilsenergysavingstarrating
Unitmanufacturingcost
Customer Need
1 Mobility
2 Noise level
3 Convenient
4 Flexible movement
5 Free from bacterial/Safe to use
6 Effective sucking ability
7 High suction rate
8 High suction energy and its energy
consumption
9 Easy to install
10 Cost-effective
11 Energy-saving
Table7: Customer-NeedMatrix
Chart

26. 26
4.1.1 Competitive Benchmarking Information
Type Descriptions
Saliva Ejectors Hygoformic Disposable Saliva Ejector and Tongue Protector
The unique coil design is adjustable in shape and size and
ensures patient comfort and nonclogging operation. The coil
eliminates the irritating sharp edges common in other disposable
saliva ejectors. The aspirating holes are placed to avoid contact
with the tongue and tissues and will not become blocked.

27. 27
Comfort Plus™ Premium Saliva
Ejector
The Comfort Plus™ Premium Saliva Ejector uses a patented
design featuring rounded edges, smooth surfaces and perfectly
placed suction ports that help to enhance patient comfort while
protecting delicate mucosal tissue.
Unlike traditional blunt-ended saliva ejectors that can lock onto
tissue and traumatize patients, the unique streamlined Comfort
Plus™ suction tip design:
● Reduces patient discomfort
● Optimizes fluid removal
● Minimizes trauma to mucosal tissue
● Facilitates uninterrupted fluid and light debris removal
● Prevents tissue from blocking suction
● Allows for extended use
● Provides you with greater efficiency
The Comfort Plus™ Saliva Ejector is also perfectly bendable, yet
firmly holds the shape you create.

28. 28
Metric Units
Products
Saliva Ejectors
Hygoformic
Comfort Plus™
Premium Saliva Ejector
Mr. ThirstyTM
Wheel with stopper M
- - YES
Attenuation of noise level
below 40 Hz
dB - - Yes
Tubing made of fibre-
optics like composite
materials
m
No No Yes
The tip and body of the
tubing is made of rubber
N
Plastic Yes Yes
Inner wall of the tubing is
coated with bio-film
mm
No No
Yes. The coated
later is 2 mm thick
of tetracycline that
could lasts for 1 year
Diameter expandable
waste bag
scm
10cm 15cm 20 cm
Suction flow rate lpm No No
Suction flow rate of
28 lpm
Has multiple holes found
along the tubing No No Yes
Stress Strain test on the
wheel
Pa
1.89 x 109 1.77 x 106 2.01 x 106
Bending strength (on the
wheel and the tip of the
ejector)
MPa
2.05 x 106 1.07 x 106 4.13 x 106
Fulfils energy saving star
rating
kW
No No Yes
Unit manufacturing cost RM 199.90 230.00 636.38
Table 8: Competitive benchmarking chart based on metrics

29. 29
Concept
Generation
-Problem and Solutions
-Initial Concepts & Challenges Faced

30. 30
5.0 Problems and Solutions
Our team set out the project by thinking on which lab equipment to choose as the
experimental apparatus. Eventually, we had chosen dental equipment, which is saliva ejector
because we think that dentists have a lot rooms for dentists to realize. The use of saliva
ejector is part and parcel of dental procedures, thus making it more necessary for the
reinvention and innovation to take place on saliva ejector.
Our team applied the Five-Step Method to break a complex problem into simpler
subproblems. The steps are as below:
Step 1: Clarify the Problem
Step 2: Search Externally
Our team interviewed lead users such dentists and dental hygienist who could explain to us
what they actually need in a saliva ejector.
The patents we refer to was:
1. http://www.freepatentsonline.com/3864831.html
2. http://www.freepatentsonline.com/3777756.html
At this point, our team has decided to think the saliva ejector as one of the functions found in
a portable dental unit. This idea is revolutionary in comparison with other,
Step 3: Search Internally
Our team has found many inspirations from the internet.
Step 4: Explore Systematically
Concern Solutions to subproblem
Portable 1. Install wheel and a stopper to control its
movement
2. The saliva ejector is made of light material
Safe to use 1. We have bio-film to kill bacteria
2. Use biocompatible material
Challenge
To design an application that boost
dentists’ daily mission worldwide by
means of saliva ejector
How can it be made portable?
How to include various functions?
How to ensure it is energy-saving?
How to effectively suck all the saliva?

31. 31
5.1 Our Initial Concepts and Challenges Faced
Diagram 1: The initial concept A Diagram 2: Concept B
At first, we thought of having a saliva ejector that has two suctions: high- and low- suction. A
compressor is installed to suck the saliva, blood and debris produced during any dental
treatment. The parts are connected with tubing. There is container that acts as waste bag.
However, the challenges that we faced for the first concept was that it was not portable, the
waste bag is too rigid and occupied much spaces. In addition, the product could be hardly
lifted up nor moved from one place to another. There are chances that the backflow of debris
could happen as well.
Eventually, after spending some time on brainstorming for better ideas, we came up with a
concept B. The concept B was later on refined and transformed into the final product which
we deem satisfactory. The customers, several lead users such as dentists and some patents
found on the web did really help us to discover more possible innovations.
Our final concept C was chosen based on the results of concept scoring which will be due
later in the following report. Basically, concept C includes and predominates all of the
features found in the previous two concepts A and B. Some notable features are as below:
 Bio-film on the lining of the inner wall of the tubing
 Tubing has branches and holes around its circumference
 Has wheels and stopper Expandable waste bag
 Saliva ejector sucks at a certain interval of 2 seconds to save electricity and produced
less noises
 Hard, durable and light casing. It is also for aesthetic purpose.
 It has disinfectant container to hold thus eliminating bacteria when the saliva ejector
is not in use

32. 32
Concept Selection
-Concept Scoring
-Concept Selected

33. 33
5.0 Concept–Scoring Matrix
Concept Scoring Matrix of Dental System
Selection Criteria Weight Concept A Concept B Concept C
Rating Weighted
Score
Rating Weighted
Score
Rating Weighted
Score
Safety
Valve
Bio-film
Hazardous material is recycled
25
10
5
10
0
0
6
0
0
20
7
6
7
70
30
70
8
7
8
80
35
80
Flexibility
Bendable tubing and its tips
Expandable waste bag
25
15
10
5 75 5 75 7 105
3 30 3 30 6 60
Energy Saving
Achieve Energy-Saving Star
Rating
Periodical suctioning
10
5
5
3 15 3 15 5 25
2 10 4 20 7 35
Durability
Pass the falling test
5
5 3 15 4 20 8 40
Aesthetic
Shape (including components)
Smooth, non-weary surface
5
3
2
6 18 7 21 10 30
7 14 8 16 10 20
Cost
Material
Tooling
15
10
5
5 50 6 60 10 100
4 20 5 25 10 50
Manufacturing Ease
Low-cost material
Low Complexity of parts
15
8
7
5 40 6 48 6 48
4 28 5 35 5 35
Total Score 100 335 535 743
Rank 3 2 1
Hence, the concept C is chosen. Please refer to the full sketch of Concept C.
Table 13: Concept Scoring Chart

34. 34
ConceptSelected

35. 35
Concept Testing
-Define the Purpose of the Concept Testing
-Choose a Survey Population
-Choose a Survey Format
-Communication the Concept
-Measure Customer Response
-Interpret the Results

36. 36
6.1 Define the Purpose of the ConceptTesting
The purpose of having concept testing is that we want to know how much more
improvements that could be made possible by our core team so as to meet customers’ demand.
We want to penetrate the market with strong features favoured by our trustworthy customers.
If the product did not receive good responses, we will have to stop the development process.
6.2 Choose a Survey Population
The primary consumers are dental patients
The secondary consumers are dentists and dental hygienists.
6.3 Choose a Survey Format
Our team used the following methods:
 Face-to-face interaction
 Telephone
6.4 Communicate the Concept
The concept is communicated with as much richness as possible by the following ways:
 Verbal description
 Sketch
 Photos and rendertings
We used this diagram to communicate with prospects
6.5 Measure CustomerResponse
Concept testing is conducted to verify that the final product concept for the saliva ejector
mentioned above meets the customer needs adequately. A survey in form of face-to-face
interview is conducted with 10 persons who included both patients and dentists (practitioners)
as our survey population.

37. 37
The results from the survey are shown below:
Number of
respondent
Fraction of
respondent
I would definitely not choose this saliva ejector. 1 0.04
I would probably not choose this saliva ejector. 2 0.08
I might or might not choose this saliva ejector. 8 0.32
I would probably choose this saliva ejector. 5 0.20
I would definitely choose this saliva ejector. 9 0.36
Total: 25 1.00
Table 14: Results of concept test survey
6.6 Interpret the Results
From the results, more than 50% of respondents indicate that they would probably or
definitely choose this saliva ejector. As a conclusion, it is verified that the final concept for
the saliva ejector adequately meets the customer needs.
We are also interested in estimating the demand for the saliva ejector in one year.
Assume that the existing saliva ejector are currently sold into the target market at a rate of 106
units per year (N=1 000 000). Assume that 35 percent of the hospital in the target market will
be aware of this saliva ejector and have convenient access to the dealer (A=0.35). From the
results of concept test survey conducted, we obtain the definitely-would-buy fraction of 0.36
(Fdefinitely=0.36) and probably-would-buy fraction of 0.20 (Fprobably=0.20). If we use a value of
0.4 for Cdefinitely and 0.2 for Cprobably, then the quantity of the saliva ejector expected to be sold
in one year, Q is
184.020.02.036.04.0  probablyprobablydefinitelydefunitely FCFCP
and
yearunitsPANQ /400,64184.035.0000,000,1 
This quantity covers about 6.44% of total saliva ejector sold in one year, which is really
encouraging. Thus, we decided that this product worth developing for the mass market.

38. 38
Results
-Modeling
-Technical Drawings
-Analysis
-Material Selection
-Manufacturing Processes
-Estimation of Material Costs
-Cost-to-Produce Product

39. 39
7.0 Modeling
The solid model of the final product is created by using SolidWorks2012 :
Figure 1 : Front View (closed)
Figure 2 : Back view (closed)

40. 40
Figure 3 : Front view (open)
Figure 4 : Casing with empty components

41. 41
Figure 5 : Casing’s lock
Figure 6 : Compressor

42. 42
Figure 7 : Low Pressure Ejector
Figure 8 : High Pressure Ejector

43. 43
Figure 9 : Syringe
Figure 10 : Top Handle

44. 44
Figure 11 : Side Handle
Figure 12 : Wheel

45. 45
Figure 13 : Waste Tank
Figure 14 : Water Supply Bottle

46. 46
Figure 15 : Exploded view

47. 47
7.1 TechnicalDrawings

48. 48

49. 49

50. 50

51. 51

52. 52

53. 53

54. 54

55. 55

56. 56

57. 57

58. 58

59. 59

60. 60

61. 61

62. 62

63. 63

64. 64

65. 65

66. 66

67. 67
7.2 Analysis
We have done some statics simulation of some of the parts of our product using SolidWorks
2012. The loads I applied are all set to be 100N.
Above and below are the simulations done on casing which shows the displacement and
stress on it. The fixed supports are set below the base which is the stand and also wheels. The
force is applied above the base of casing due to the weight of compressor, waste tank and
water supply bottle. We can see that the deformation is so insignificant hence it’s safe.

68. 68
Above and below are the simulations done on waste tank which shows the displacement and
pressure on it. The fixed supports are set below and surrounding the wall. The pressure is set
to be 100Pa. From the results we can confirm that our waste tank is safe enough to be used
since it can resist high pressure.

69. 69
Above and below are the simulations done on the back part of our product which is the holder
to pull our product. The purpose is to make sure that the handle is strong enough to be pulled.
Results of simulations show that there’s no problem with the materials and design that we’ve
chosen.

70. 70
7.3 Materials Selection
The main concepts and objectives for our product material selection are to be cheap, light,
durable and strong. Based on our design, the Mr. Thirsty is using the concept of a luggage
bag or a travel bag because the appearance of the design is almost the same.
For the outer case of this product, instead of using fabric like a common luggage bag, we are
using other material to make a hard case for Mr. Thirsty. Thus we are using Acrylonitrile
Butadiene Styrene (ABS) which is a common thermoplastic. ABS is amorphous and
therefore has no true melting point. The advantage of ABS is that this material combines the
strength and rigidity of the acrylonitrile and styrene polymers with the toughness of the
polybutadiene rubber. The most important mechanical properties of ABS are impact
resistance, toughness and chemical resistance. ABS can be made in many colors, in either
smooth or textured finishes; hence it will attract many customers.
For the side, top and back handles and wheels, we are using the same material as the case of
the design which is Acrylonitrile Butadiene Styrene (ABS). This is because the handles and
wheels are a very critical parts which they have to withstand the weight of the whole body
either upward or downward force. But for the back handle, the hollow tube which can be
extended, it is made of Stainless Steel Alloy. This type of alloy is chosen because it has to be
a lot stronger, tougher and has higher strength so that the tube would not be easily damaged
or bent. Other than that, stainless steel alloys will not rust because it contains sufficient
chromium to form a passive film of chromium oxide unlike other steel, which it will prevent
further surface corrosion and blocks corrosion from spreading into the metal's internal
structure. Although stainless steel is a bit heavy, but the handle tube is a hollow tube with a
very thin wall, thus the weight of the tube can be reduced.
The tip of the saliva ejector also using Stainless Steel Alloy because the tip will be placed in
the patients mouth, thus, it cannot be rust and cannot be corroded. For the dental tubing
which is saliva ejector tube and the water tube, we are using a Composite Material which is
flexible, durable and can withstand high pressure. The composite material also is a chemical
resistance, because all dental tubing needs a good hygienic condition. Then we are adding a
layer of Tetracycline Antibiotics is a bacterial resistance that acts as treatment for any
infections in the saliva of a patient. This is because, sometimes backflow of the saliva can
happen. Hence, to avoid the infectious saliva of the patient from being swallowed, this
tetracycline can treat the bacteria and the saliva is no more harmful. For the waste tank and
the water tank, we are using a common material which is PVC. It’s cheap, light and can be
manufactured easily. The valve which is installed at the inner portion of the tubing is made
up of fluorpolymer, reinforced with carbon fibres. The waste bag is made up of elastic latex
material so that it could expand when storing wastes. The elasticity of the waste bag gives it
an advantage to store more volume of wastes such as amalgam which is highly dangerous.
Basically, the internal components of the compressor are made of AISI 4340 Steel Alloy
because it has a very high tensile strength to withstand great pressure of the compressor. But
to make the whole compressor lighter, we are using Aluminium Alloy for the casing of the
compressor and other parts which do not involve in work of high pressure. Thus only a
portion of materials of this product have a quite heavy weight. But these materials chose
because we want to make this product durable and can be used for a long term.

71. 71
7.4 Manufacturing Process
Basically, we have two main processes to make the parts for this product. Which are:
1. Permanent mold casting
2. Injection molding and extrusion
We are using permanent mold casting for all the steel parts which are the internal components
of the compressor, the casing of the compressor, tip of saliva ejector and the tube for the back
handle. All the materials, AISI 4340 Steel Alloy, Aluminium Alloy and Stainless Steel Alloy,
are all metal type materials. By permanent mold casting, good surface finish can be achieved.
For the side, top and back handles, wheels, all dental tubing, water tank, waste tank and the
body of the design, we are using injection molding and extrusion because ABS and PVC is a
plastic material which can be shaped easily. Raw material of ABS and PVC are fed into a
heated barrel, mixed, and forced into a mold cavity where it cools and hardens to the
configuration of the cavity. The composite material for the dental tubing is also easy to
manufacture because it is just the same with any other type of plastics.
7.5 CostEstimation
Standard Components
Component Unit Cost per unit
(RM/unit)
Total cost
(RM)
ISO Hex Screw
Grade AB, M5
20 1.00 20.00
Total cost: 20.00
Table: Cost estimation for standard components
Custom Components
Raw Materials Costs:
Part Material Mass
(kg)
Cost per unit
mass
(RM/kg)
Total cost
(RM)
Internal
components of
compressor
Alloy steel
AISI4340
1.5 28.75 43.125
Casing of the Aluminium alloy 1.0 21.25 21.25

72. 72
compressor
Body, All
handles and
Wheels
Acrylonitrile
Butadiene
Styrene (ABS)
2.0 54.50 109.00
Water tank
and Waste
tank
PVC 0.4 5.60 2.24
Tube for back
Handle and
Saliva ejector
tip
Stainless Steel
Alloy
0.8 16.40 13.12
All dental
tubing
Composite
material
0.5 31.10 15.55
Total raw materials cost : 204.30
Table: Raw materials costs estimation for custom components
Manufacturing and Tooling Costs
Manufacturing/
Assembly process
Processing time
(unit/hr)
Cost per unit hour
(RM/hr)
Total cost
(RM)
Cast Molding 5 120.00 60.00
Injection
molding and
extrusion
5 80.00 80.00
Add layering of
tetracycline
(bio-film)
4 25.00 25.00
Fastening 20 20.00 20.00
Total manufacturing cost : 185.00
Table: Manufacturing costs estimation for custom components

73. 73
Add on Costs:
Add on
Material Mass
(kg)
Cost per unit
mass
(RM/kg)
Total cost
(RM)
Tetracycline
antibiotics Tetracycline 0.03 1423.00 42.69
Total add on cost: 42.69
Table: Add on costs estimation for custom components
7.6 Cost-to-produce
Cost-to-produce = Total cost for standard components + Total cost for custom components
= Total cost for standard components + (Total raw materials cost + Total
manufacturing cost + Total add on cost)
= RM 20.00+ (RM 204.30 + RM 185.00 + RM 42.69) = RM 451.99

74. 74
Summary
The product that we built is from concept C. It is marketable as the demand is quite high and
we believe the profit could soar with proper marketing and management.
Let’s have a look at the final specifications of our proudest product:
Size: 10.5” x 14.5” x 24”(27 cm x 36 cm x 61 cm)
Volume: 1.81 cu. ft. (0.05 m3)
Weight: 43.5 lbs (19.7 kg)
Power Source: AC Dual Voltage Manual-Switching
120V / 230V at 50Hz / 60Hz
Current Rating: 6.3A at 120 VAC, or
3A at 230 VAC
Power Rating: 800 W
Operating Pressure: 45 - 50 PSI (344 kPa)
Average Air Flow Pressure: 30 PSI, 0.33 SCFM (275 kPa, 9.35 liters/min)
High Volume Vacuum: 3.0 SCFM @ -4” Hg (84.9 liters/min)
Low Volume Vacuum: 1.4 SCFM @ -1.5” Hg (39.6 liters/min)
Water ReservoirCapacity: 33.9 fl. oz. (1.0 liter)
Water Flow: 5.91 fl. oz./min (0.175 liter/min)
Waste Tank Capacity: 1.08 gal. (4.08 liters)
Noise Level: 28 dBA
Altitude: 0 to 3048 meters (0 to 10,000 feet)
Duty Cycle: Continuous
Warning!
This device has been tested and found to comply with the emissions requirements of IEC
60601-1-2:2001-09. These requirements provide reasonable protection against harmful
electromagnetic interference in a typical medical installation. However, high levels of radio-
frequency (RF) emissions from electrical devices, such as cellular phones, may disrupt the
performance of this device. To mitigate disruptive electromagnetic interference, position this
device away from RF transmitters and other sources of electromagnetic energy.

75. 75
Conclusions and
Recommendations
The Mr. ThirstyTM can be sold
Recommendations:
We would like to suggest this product to be patented.
We would like to suggest that there is a flexible mirror placed along the tubing outer surface
so as to assist dentists in dental operation.
We would like to suggest there is a micro-camera to be installed so as to boost students’
understanding towards dental procedures. It can be served as an educational tool in future.
We would like to suggest that there is smell eliminator to eliminate halitosis so that dentists
can work happily, comfortably and safely.
Reference
[1] Wise GEEK (2003), Retrieved 29 April 2012, from http://www.wisegeek.com/what-is-a-
saliva-ejector.htm
[2] Lee Pin Enterprise Sdn Co. Ltd (2010), Retrieved 29 April 2012, from
http://www.allindentpro.com/english/dental_saliva_ejector.htm
[3] Wikipedia-Energy Star (2012), Retrieved 29 April 2012, from
http://en.wikipedia.org/wiki/Energy_Star
[4] Delmar's Dental Assisting: A Comprehensive Approach (2003), by Donna J. Phinney,
Judy H. Halstead, from
http://books.google.com.my/books?id=6a9ARKqM1K4C&pg=PA282&lpg=PA282&dq=Typ
es+of+Saliva+ejector&source=bl&ots=uEDS5kM-
BK&sig=hsnmmSTyFyIo5UvKXQX4zRWjLss&hl=en&sa=X&ei=JUm8T7fLCILqrAfbo5S
mDQ&ved=0CFEQ6AEwAA#v=onepage&q=Types%20of%20Saliva%20ejector&f=false
[5] Live StrongTM.com (2012), Retrieved 30 April 2012, from
http://www.livestrong.com/article/383621-statistics-of-health-risks-from-eating-fast-
food/#ixzz1tMlUm0Vn

76. 76
[6] R-Tech Dental (2011), Retrieved 30 April 2012, from
http://rtechdental.com/index.php/news/45-how-do-i-stop-my-saliva-ejector-tip-from-falling-
off
[7] SciVerse (1998), Retrieved 30 Aprtil 2012, from
http://www.sciencedirect.com/science/article/pii/S0195670198903085
[8] 2012 Freelin-Wade Co. (2011), Retrieved 30 April 2012, from http://www.freelin-
wade.com/dental-vacuum-tubing.html
[9] Dental Suction Blog (2011), Retrieved 30 April 2012, from
http://dentalsuction.wordpress.com/2011/08/21/hygoformic-saliva-ejector-product-review/
[10] World Work Dentistry Dedicated (2012), Retrieved 30 April 2012, from
http://www.worldwork.it/saliva-ejectors.html
APPENDIX
Appendix A: Interview Questions and Answers
Prospect: Dr. Eshamsul Bin Sulaiman Date: 8th March 2012
Interviewer: Mr. Lee Chia Chun Time: 11.00am – 12.00pm
Venue: Dean Office of Faculty of Dentistry,
University of Malaya.
Telephone (office): 03-79674806
Currently uses: Hygoformic Saliva Ejector
Type of user: Practitioner/Applicator
1. When does dentist/dental hygienist use saliva ejector?
A saliva ejector may sit in the mouth during a dental procedure such as filling teeth or the
dentist may insert it into the mouth at intervals during the procedure.
2. What are the common problems faced by patients when using saliva ejector? (User-
friendly? Ergonomic? Cost-effective? Energy-efficient? Noisy?
-Noises produced by the saliva ejector compressor is noisy
-Tip keeps fallen off
-Backflow of debris might happen without the present of valve and when is assisted by the
differential pressure

77. 77
3. In your opinion, what is the problem with the current saliva ejector in the market?
The problem with the current saliva ejector is that it produces unwanted noises. The noise
level could affect dentist’s concentration and patient’s comfort at times.
4. Is it safe for patients to close their mouths around saliva ejector tip? Why?
It is not a good practice to have patients close their mouths around saliva ejector tips
because this causes back pressure in the lines. The common practice of instructing patients
to use the saliva ejector like a straw is unfortunate, uninformed, unsanitary, and potentially
dangerous. This backflow problem has been well documented for almost 20 years. In 1993,
researchers at the University of Alberta in Canada published concerns and documented
backflow of pathogens from saliva ejector lines. Extensive follow-up studies at the University
of Montreal in 1998 found that bacteria associated with backflow were present in
approximately 25% of the analyzed samples, with levels ranging from 1 cfu to 300 cfu per
occurrence. Most of the bacteria isolated from backflow samples included staphylococci,
micrococci, and nonfermentive Gram-negative rods. Also found in the backflow fluids were
pathogens such as Pseudomonas aeruginosa, Staphylococcus aureus, and Legionella
pneumophila. Although these studies did not provide direct proof of cross-contamination,
they suggested an infectious risk since potential pathogens may be shed from tubing biofilms.
Even if the risk of cross-contamination is low, regular disinfection of dental unit waterlines,
including the saliva ejector line, is essential because biofilms can serve as a reservoir for
these pathogens.
Even though disinfectant chemicals reduce microorganisms in the effluent water, they do not
completely destroy the biofilm matrix in dental unit waterlines even with regular treatments.
You must also consider that chemical disinfection can result in the slow release of potentially
toxic or caustic substances from the biofilm matrix. As prudent clinicians, we need to be
concerned about two potential problems. First, bacteria in the dental unit and saliva ejector
tubing rapidly recolonize from the residual biofilm in the lines and, second, chemical
disinfectant agents that can become trapped in the matrix may represent an additional risk to
patients when and if they close their mouths over the saliva ejector causing backflow.
5. In corresponding to the previous question, what are your recommendations to ensure
no backflow from the ejector into the patient’s mouth could occur?
The American Dental Association and the Centers for Disease Control and Prevention in
Georgia urge dentists to ensure that the tube hangs below the patient’s head during dental
visits and to abolish the practice of asking patients to close their lips around the applicator
head.
6. What modifications that could be done to boost dental procedures? (in point form)

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Valve-It can be installed at the inner portion of the tubing to prevent backflow of debris
suctioned earlier
Tubing has branches and holes along its circumference-The tubing is made up of flexible
material so that it can be bent here and there and stay at the required position when there is
not external forces applied. In addition, the holes found along its circumference grants it more
suctioning ability and rate. The branches of the tubing enable it to reach out different areas
inside the mouth.
7. Do you think the innovated saliva ejector should include tongue retractor as well?
We use tongue retractor because some adults, mostly are children, feel unease with the saliva
ejector placed inside their mouth and attempt to roll their tongues here and forth inside the
mouth. This has gravely obstructed dental procedures. To avoid this problem, it is an added
bonus to have tongue retractor. However, you should always ask patients’ opinion whether
they like the idea of clamping their own tongue for as long as the dental procedures would
last. It is optional though.
8. As we know, the general suctioned wastes are saliva, blood and debris resulted from
the dental procedures. This debris may consist of amalgam, mercury and other metals
that might be detrimental to human health. In your opinion, how should the waste to be
managed?
The amalgam must be collected in a waste bag and then recycle it.
9. In corresponding to question 8, what is stepto manage the amalgam waste?
Surely. (The steps can be summarized as below)
i. Stock amalgam capsules in a variety of sizes to minimize the amount of amalgam
waste generated.
ii. Amalgam waste may be mixed with body fluids, such as saliva, or other potentially
infectious material, so use personal protective equipment such as utility gloves, masks,
and protective eyewear when handling it.
iii. Contact an amalgam waste recycler about any special requirements that may exist in
your area for collecting, storing and transporting amalgam waste. If you need to find a
recycler, check with your city, county or local waste authority to see whether they
have an amalgam waste recycling program.
iv. Store amalgam waste in a covered plastic container labeled “Amalgam for Recycling”
or as directed by your recycler. Your recycler may have its own requirements, so ask
your recycler about containers and what may be placed in them.
v. Look for recyclers who comply with the ADA-ANSI standard. This standard is
meant to encourage recycling.
10. Would you buy the newly innovated saliva ejector in the future that meets your
requirements?
Yes, why not.

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Appendix B: Phone Interview Guide for ConceptTestof the Saliva Ejector
CONCEPT TEST SURVEY- DENTAL SALIVA EJECTOR
I am students of the Department of Mechanical Engineering, Faculty of Engineering, of
Malaya. I am gathering information for a new saliva ejector and am hoping that you would
be willing to share your opinions with us. Your kind cooperation is highly appreciated. Thank
you.
Have you ever used saliva ejector during dental procedures?
……………………………………..
<If the response is no, the respondent is thanked and the survey is ended.>
If the product Ire priced at RM 451.99, how likely would you be to choose this product
instead of other existing saliva ejectors and recommend dentists/dental hygienists to purchase
our dental saliva ejector unit?
a) I would DEFINITELY NOT choose this saliva ejector.
b) I would PROBABLY NOT choose this saliva ejector.
c) I MIGHT or MIGHT NOT choose this saliva ejector.
d) I would PROBABLY CHOOSE this saliva ejector.
e) I would DEFINITELY CHOOSE this saliva ejector.

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End of Report
Our team wanted to express the warmest gratitude to Dr. Mohd Faizul Bin Mohd Sabri.
Thank you
Regards,
The Core Team of Mr. ThirstyTM
MUHAMMAD SYARAFFI BIN SHAARANI KEM 100040
TAN KIM GUAN KEM 100052
LEE CHIA CHUN KEM 100017
MOHD EDZADZUL BIN MOHD NOOR KEM 100029