Questions and Answers
What are safety precautions that should be taken in the dental laboratory?
Where would the dental laboratory be located in a dental office?
Separate area of the dental office, away from the patient treatment area.
What specialty practices might have a more extensive laboratory set up?
Pediatric dentistry, orthodontics, and fixed and removable postorthodontics.
What is an example of a contaminated item in the dental laboratory?
Signup and view all the answers
What are wall-mounted bins used for?
Signup and view all the answers
What are work pans?
Signup and view all the answers
Why might the work pans be color coded?
Signup and view all the answers
Why is a heat source required in the dental lab?
Signup and view all the answers
What can be used to heat the wax?
Signup and view all the answers
When can we use the Bunsen burner?
Signup and view all the answers
Why is it important to fully turn the gas on or off?
Signup and view all the answers
What is a model trimmer?
Signup and view all the answers
What is a vacuum former?
Signup and view all the answers
How does a vacuum former work?
Signup and view all the answers
What is a vibrator used for?
Signup and view all the answers
What handpiece is required in the dental laboratory?
Signup and view all the answers
What is a sandblaster?
Signup and view all the answers
What is an articulator used for?
Signup and view all the answers
What does the articulator allow the dentist to do?
Signup and view all the answers
What is the face bow?
Signup and view all the answers
What is the centric relation?
Signup and view all the answers
What is the dental lathe used for?
Signup and view all the answers
When is pumice used?
Signup and view all the answers
What is a wax spatula used for?
Signup and view all the answers
What determines the mixing spatula you have to use?
Signup and view all the answers
What are rubber bowls used for?
Signup and view all the answers
What piece of equipment is used to grind away plaster or stone?
Signup and view all the answers
What piece of equipment does the dentist use to determine centric relation on a diagnostic model?
Signup and view all the answers
What is the most common wax spatula size used in the lab?
Signup and view all the answers
What are dental models used for?
Signup and view all the answers
What are gypsum products used for?
Signup and view all the answers
What are the chemical properties of gypsum?
Signup and view all the answers
What is the setting reaction of gypsum?
Signup and view all the answers
What are the clusters that form when mixing gypsum with water called?
Signup and view all the answers
What are the three forms of gypsum products used in pouring models?
Signup and view all the answers
What is model plaster used for?
Signup and view all the answers
What is dental stone used for?
Signup and view all the answers
What is high strength stone?
Signup and view all the answers
What happens when too little water is used when mixing gypsum?
Signup and view all the answers
What happens when too much water is used when mixing gypsum?
Signup and view all the answers
What is another term for dental model?
Signup and view all the answers
What are the two parts of a dental model?
Signup and view all the answers
What is the anatomical portion created from?
Signup and view all the answers
What does the art portion form?
Signup and view all the answers
What are the three different types of pouring methods?
Signup and view all the answers
What is the double pour method?
Signup and view all the answers
What is the box and pour method?
Signup and view all the answers
How much should the completed box in a box pour method extend?
Signup and view all the answers
What is the inverted pour method?
Signup and view all the answers
What is the most common way of pouring up?
Signup and view all the answers
How long should you wait before you separate the model from the impression?
Signup and view all the answers
Which of the two models do you begin measuring and trimming first?
Signup and view all the answers
Study Notes
Safety Precautions in the Dental Laboratory
- No eating, drinking, or smoking allowed in the lab.
- Cosmetics should be kept away to prevent contamination.
- Personal protective equipment (PPE) is mandatory for safety.
- Hair must be secured to avoid interference during procedures.
- Any accidents must be reported to the dentist without delay.
- Always adhere to manufacturer instructions for equipment usage.
- Clean the work area before and after procedures to maintain hygiene.
Location and Setup of Dental Laboratory
- Dental laboratories are usually separate from patient treatment areas in dental offices.
Specialty Practices with Extensive Laboratories
- Pediatric dentistry, orthodontics, and fixed/removable prosthodontics require more extensive laboratory setups due to higher lab work demand.
Contaminated Items in the Lab
- Impressions can be contaminated with blood or saliva, necessitating disinfection before and after use.
Storage in the Dental Laboratory
- Wall-mounted bins are utilized to store plaster, stone, and investment materials, protecting them from moisture.
Work Pans
- Open plastic containers used to hold ongoing laboratory work for individual patients, typically labeled for identification.
Color Coding Work Pans
- Color coding indicates the type of procedure being performed.
Heat Sources in the Dental Laboratory
- A heat source is essential for heating wax and other materials used in dental procedures.
Heating Wax
- Propane or butane torches are effective for heating wax and other lab materials.
Use of Bunsen Burner
- A Bunsen burner can be utilized if a gas line is installed in the laboratory.
Gas Safety
- It is crucial to fully turn the gas on or off to prevent leakage from loose connections.
Model Trimmer
- A device for trimming stone or plaster models in the dental lab.
Vacuum Former
- An appliance used for constructing custom trays, mouth guards, and orthodontic positioners.
Operation of Vacuum Former
- The heating element softens thermoplastic resin, while a vacuum shapes the plastic around models.
Purpose of Vibrator in Lab
- A vibrator removes air from plaster or stone mixtures, aiding the material's flow when pouring diagnostic models.
Low-Speed Handpiece
- Essential for trimming custom trays, adjusting dentures, and polishing indirect restorations.
Sandblaster
- A handheld tool that creates etching on metals, porcelain, or acrylic.
Articulator
- A mechanical device for holding dental models, aiding in reproducing mandible-maxilla relationships.
Functions of the Articulator
- Used in the fabrication of dentures, bridges, crowns, inlays, and onlays.
Face Bow
- Instrument for determining maxillary arch position relative to temporomandibular joints.
Centric Relation
- Measurement aligning teeth when joints are accurately positioned before contact.
Dental Lathe
- Used for polishing or trimming custom trays, provisional units, and indirect restorations.
Pumice in Polishing
- Pumice and polishing agents are used under a protective pan to manage spatter.
Wax Spatula
- A double-ended instrument used primarily in waxing patterns in the lab.
Choosing a Mixing Spatula
- Selection depends on the dental material's strength being mixed.
Rubber Bowls
- Used for mixing alginate and other dental materials in labs and treatment areas.
Grinding Equipment
- Model trimmer is utilized for grinding away plaster or stone.
Diagnostic Model Relation
- The face bow is the tool for assessing centric relation on diagnostic models.
Common Size of Wax Spatula
- The #7 wax spatula is predominantly used in laboratory settings.
Study Casts
- Dental models are accurate reproductions of maxillary and mandibular arches and soft tissues.
Uses for Dental Models
- Aid in diagnosis and planning for prosthetics, orthodontic treatment, presentations, custom trays, and mouthguards.
Gypsum Products
- Evaluations include model plaster, dental stone, and high-strength stone for creating dental models.
Chemical Properties of Gypsum
- Exist in two forms: dehydrate and hemihydrate.
Setting Reaction of Gypsum
- Mixing gypsum powder with water forms clusters of hemihydrate crystals.
Crystallization in Gypsum
- Clusters formed during the mixing process are known as nuclei of crystallization.
Gypsum Mixing Ratios
- Model plaster: 100g with 45-50ml water.
- Dental stone: 100g with 30-32ml water.
- High-strength stone: 100g with 19-24ml water.
Effects of Water on Gypsum Mix
- Too little water results in a short working time and rapid drying.
- Excess water leads to weaker, thinned models with prolonged setting time.
Two Parts of a Dental Model
- Comprises an anatomical portion from alginate impressions and an art portion forming the base.
Pouring Methods for Models
- Various methods include double pour, box-and-pour, and inverted pour techniques.
Double Pour Method
- The anatomical part is poured first, followed by a second mix for the art portion.
Box-and-Pour Method
- Involves surrounding the impression with a wax box for pouring.
Inverted Pour Method
- A single-step method where a large mixture is poured into the impression upside down.
Separating Models from Impressions
- Wait 46-60 minutes post-pour before separating the model from the impression.
Measuring and Trimming Models
- Begin with trimming and measuring the maxillary model first.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge on laboratory materials and safety procedures from MDA Chapter 47. These flashcards cover essential safety precautions every dental professional must follow in the workplace. Perfect for preparing for exams or refreshing your understanding of dental lab safety.