DENT 165: LO1- Bite Reg & Alginate Imps

why is a bite reg taken?

-for an accurate recod of client's centric occlusion

-to verify how the client bites and closes on their posterior teeth

-to accurately trim the client's diagnostic study model

what is the bite reg material used at saskpoly?

-Regisil: vinyl polysiloxane

what is alginate?

-an aqueous impression material used primarily for recording detail for study casts

what is an impression?

-a negative imprint of oral structures used to produce a positive replica of the structure

what is the purpose of an alginate impression?

-accurate reproduction of client's max and mand and surrounding tissues

-used in diagnosis and care planning

-pre/post tx

trays

-available in a variety of sizes and materials

-disposable or single use made of plastic

-autoclavable or permanent made of metal

tray selection: each tray should

-be wide enough to allow 6mm thickness of imp material on facial/lingual aspects of teeth

-be long enough to extend beyond the last tooth in the arch to include the retromolar or tuberosity area

-be deep enough to allow 2-3mm depth of alginate beyond occlusal and incisal edge

-be comfortable for client

seating the tray: mand

-tray is seated over the posterior/anterior teeth and gently lowered simultaneously

seating the tray: max

-tray is seated over the biting surfaces of the post teeth first then over the ant teeth

why do we sometimes add wax to the tray?

-to extend the length of the tray

-retains the material within the tray to prevent running down the throat

-records accurate impression of vestibule

-prevent injury of impingement to soft tissues

-prevents undue penetration on the incisal/occlusal surfaces

how should client be seated for taking a mand impression

-seated with the chair slightly reclined so the occlusal surfaces are parallel to the floor when their mouth is open

seating the mand impression tray: where should the operator be?

-standing facing the client

-standing at 7:00

how should client be seated for taking a max impression?

-upright position so the occlusal surfaces of teeth are parallel to floor

seating the max impression tray: where should the operator be?

-standing beside the client towards the back

-standing at 11:00

physical properties of alginate

-powder

-water

-strength & quality

-surface accuracy

physical properties of alginate: powder

-material deteriorates on standing especially at higher temps and humidity

how do we ensure the material does not deteriorate?

-keep container closed and stored in a cool dry place

-use individually sealed packaged to eliminate problems w/ heat/moisture

-do not agitate powders unnecessarily during mixing

-filler in most alginate is silicate dust and may cause lung problems in minors

-additives have been added to decrease dust that occurs

physical properties of alginate: water

-temp controls gelation time

-use room temp water

-water should be measured

-for hot, humid environment, use cooler water

physical properties of alginate: strength & quality

-depends on water/powder ratio

strength & quality: what will insufficient water do?

-weaken the gel (product)

-decrease flexibility and flow

-have a chalky appearance

-be thick but weak

strength & quality: what will excess water do?

-weaken the product

-be runny

strength & quality: spatulation time

-45 to 60 sec

-to achieve a homogenous creamy mix to remove bubbles and allow chemical reaction

strength & quality: undermixing

-produce an uneven chemical reaction

-not have all powder in contact with the water

-altering the water/powder ratio and the mixing time is not recommended

strength & quality: setting time

-time allotted for chemical reaction to be completed

strength & quality: working time

-allotted for mixing, loading and inserting the alginate imp

surface accuracy

-impression should be poured up within 30 min to prevent loss of water from the imp

alginate impression material

-available in regular or fast set

-setting time 3:30 min or 2:30 fast set

-Jeltrate (pink), Blueprint

-Kroma Faze (3 color system)

-always read manufacturers info regarding usage

Jeltrate instructions

-45 sec for fast set

syneresis

-materials contract slightly after setting a exclude water

-leaving imp out in open air without wrapping up

-not promptly pouring up model

imbibition

-materials absorb water, swell and distort

-wrapping in a soaking wet paper towel, rather than damp

-disinfecting beyond recommended time

-leaving water on material

which imp should be taken first to familiarize the client with the procedure?

-mand impression

preparation of client

-assemble all necessary materials

-thoroughly explain procedure (removable appliances)

-seat client in the correct position

-pre-procedural rinse

-try trays in

-converse w/ client

-instruct client to breath through nose

what to do if client starts gagging

-remain calm

-instruct client to lean slightly forward with head towards chest

-instruct client to breathe slowly through nose and exhale through mouth

-talk client through procedure

when do we remove the impression from the mouth?

-about 30 sec after loss of tackiness

what should we note before taking impressions?

-are there removable mouth appliances?

-what is the approx. size of the mouth?

-are ther labially/lingually extended teeth?

-are there tori or lesions present?

for an average mand tray size, how much material and water should be used?

-2 1/2- 3 scoops of powder

-2 1/2- 3 measures of water

why is an artificial floor made?

-space for the tongue

-this area must be blocked

what are the 3 common materials used for creating an artifical floor

-alginate

-baseplate wax

-moist paper towel

for an average max tray size, how much material and water should be used?

-3 scoops of powder

-3 measures of water

what should be included in an impression?

-all teeth and alveolar processes

-peripheral roll included

-frenums included

-no voids or tears that interfere w/ anatomy

-palatal vault recorded (max)

-hamular notch (max)/ retromolar (mand) area included

-tray centered w/ midline

-no tray exposure

legal documentation

-# of attempts

-product used

-arch

-tray size

-example: HHU, Regisil bite registration, 2 Kromafaze alginate impressions max size 4 tray, 3 Jeltrate alginate impressions mand size 22 tray.

digital intraoral scanning

-can be used for crowns, bridges, implants, surgical guides, partials, ortho, study models and Invisalign

-iTero

-Cerec

-Straumann

-SprintRav

iTero

-scanning can be done in as little as 5 mins

-can show time lapse of soft tissue changes

-can show a client what expected outcome of ortho will look like

-easier for clients to tolerate

benefits of digital study models

-unlimited storage

-instant retrieval

-environmentally friendly

-avoid possible damage