Restoration of the teeth

Always includes: Operative, Fixed Prosthodontics, Esthetic Dentistry, Occlusion

Often includes: Implants, Removable Prosthodontics, Endodontics

deals with more damaged teeth than Operative Dentistry; uses crowns and bridges as material; 

- reduce the tooth in size by taking the drill around the tooth and circumsizing it so that the crown can fix around the tooth

(usually for multiple replacement teeth)

- either removed or cemented in place

- cut own on adjacent teeth and cement the denture in place; metal framework that is fitted in place and ten replace with ceramic porcelain

size of the operating site when viewed through the loops

- linked to diameter of microscope, optical design and magnifying power

(higher the magnifying power, smaller the __________)

range of focus delivered by the tooth; 

- dependent on available lighting, optical design, magnifying power and eye's ability to focus (accommodation)

the SIZE of the image (not the clarity)

- 

- 8 and 9 have the HIGHEST contact proximally on the incisal 3rd

- use a diamond burr with high speed hand piece

- length is 1/3 longer than width

- want to taper the mesial and distal  to stabilize the crown

1) create a margin

- sit with thighs parallel, shoulders straight, and arms by your side 90 degrees

- less pressure on handpiece give more feedback from fingers to brain

negative form of the tissues of the oral cavity. 

- replication of hard and /or soft tissue in the mouth including teeth, gumgs, edentulous ridges

derived from seaweed

- used as impression material

- two types reversible and irreversible

- has sodium or potassium salts of alginic acid 

- calcium sulfate - source of Ca++ ions to form insoluble calcium alginate

- trisodium phosphate - to control working time

- diatomaceous earth - for strength

- readily absorbs water by imbibition

- gives off water by syneresis

*use it in approx. 10 mins*

(most widely used dental impression material)

type 1 (fast setting, 1-2 mins at 68 degrees Farenheit)

Type 2 (normal setting, 2 to 4.5 mins at 68 degrees Farenheit)

1) water temperature (as much as a 20 second change in gelation time maybe noticed for every degree Celsius change in temperature)

2) can do by water/powder ration but can impair OTHER characteristics

3) temperature of the room

4) amount of retarder

1) too much water = weakened final gel

2) too little water = weakened final gel

3) inadequate mixing =up to 50% decrease in strength

4) overmixing = gel will break up chemically

Difficulty of Impression

a) Grainy Material

- improper mixing

- prolonged mixing

- W:P ratio is too low

Difficulty of Impression

2) Tearing

- inadequate bulk of material in tray

- moisture contaminatin

- prolonged mixing

- premature removal from mouth

Difficulty of Impressions:

3) Bubbles

Difficulty of Impression

4) irregularly shaped voids

Difficulty of Impression:

5) Rough or chalky stone casts

- inadequate cleaning of impression

- excess water left in impressioni

- premature removal of cast

- leaving cast in impression for too long

- improper manipulation of stone

Difficulty of Impression

6) Distortation

- impression not poured immediately

- movement of tray during gelation

- premature removal from mouth

- improper removal from mouth

the mineral used for dental purposes in nearly pure calcium sulfate dihydrate (CaSO4 2H2O)

- ground and subjected to temperatures of 110 C. to 120 C. to drive off the part of the water of crystallization

 - calcium sulfate hemihydrate is then produced in the form of powder

- after water is added, it becomes calcium sulfate dihydrate 

- Type I (impression plaster rarely used today)

- Type 2 (dental plaster, plaster of paris, blue mounting stone)

- Type 3: dental stone (yellow)

- Type 4: improved stone, die stone (pink or other colors)

- Type 5 (high strength/ expansion stone)

- ESSENTIAL you get it correct for proper casts

- Microstone -> 40 ml to 140 gm

- Hard Rock -> 21 ml to 100 gm

- Mounting Stone -> 18-20 ml to 70 gm

- Labratory Plaster -> 45 ml to 100 gm

Alpha (stone crystals, more dense and stronger than beta, have a prismatic shape)

Beta (plaster crystals, crystals are spongy and irregular in shape, compared with alpha crystals)

fast setting stone for mounting study models and working models to the articulator