RPD CLINICAL - CLINICAL STAGES

Question 1

what are the clinical stages of RPD

Answer 1

visit 1 - assessment and primary impressions 
visit 2 - master impressions
visit 3 - framework trial
visit 4 - tooth trial
visit 5 - delivery (fit)
visit 6 - review

Question 2

what happens in visit 1

Answer 2

assessment

primary impressions

Question 3

what does assessment consist of

Answer 3

history and examination

Question 4

what does the history consist of

Answer 4

denture history
dental history
medical
social/personal history

Question 5

why do we take a denture history

Answer 5

it is important to get the patients opinion of any current denture as if an RPD has been worn with reasonable satisfaction it is advisable to reproduce the denture design.

Question 6

why do we take a dental history

Answer 6

recent extractions may indicate the presence of active caries or periodontal disease that needs to be addressed by preventative aspects of the treatment plan

Question 7

when taking dental history why is it important to find out when extractions took place

Answer 7

the most rapid phase of bone resorption occurs during the few months following the tooth loss – dentures constructed around the time of extractions therefore soon lose their fit

Question 8

why do we take a medical history

Answer 8

to accomodate any conditions e.g diabetes

lso, the practice of oral and denture hygiene may be compromised by a reduced ability

Question 9

why do we take a social/personal history

Answer 9

determines patient motivation

smoking habit should be noted

Question 10

what does the examination consist of

Answer 10

extra oral

intra oral

Question 11

what happens in an extra oral assessment

Answer 11

assess the facial form and symmetry. Study the jaw’s opening and closing movements alongside palpation of the TMJ and muscles of mastication. This information derived from these observations is helpful in the assessment of the health of the masticatory system.

Question 12

what happens in an intra oral assessment

Answer 12

look for the standard of oral hygiene, begin detailed examination of soft tissues (mucosa of the lips, cheeks, tongue, palate and floor of the mouth). Note edentulous spaces and distribution and alignment of remaining teeth. The form of the residual ridges and the compressibility of the investing soft tissues in the edentulous areas should be assessed visually and by palpation (incompressible areas may have to be avoided by denture margins). Assess current restorations and health of periodontal tissues.

Question 13

what are the two types of impression trays

Answer 13

edentate and dentate

Question 14

what is the difference between dentate and edentate trays

Answer 14

dentate trays have a greater depth than edentate

Question 15

how should the size of tray be selected

Answer 15

so that the teeth sit centrally within the trough of the tray and if possible there should be a space of about 4mm between the flange of the tray and the buccal and labial surfaces of the teeth

Question 16

what impression material should be selected when there is no free end saddle

Answer 16

alginate

Question 17

what impression material should be selected when there is a free end saddle

Answer 17

alginate and impression compound

Question 18

describe how the impressions tray is modified for a free end saddle

Answer 18

dead space is filled with impression compound

Question 19

why should any impression compound contacting the teeth be cut away

Answer 19

it prevents accurate reinsertion of the impressions ray and will eliminate space around the teeth necessary for a sufficient thickness of alginate used to complete the preliminary impressions

Question 20

how do you border mould for the lingual border

Answer 20

it is achieved by the patient first pushing the tongue to contact the upper lip and then thrusting the tongue into each corner of the mouth in turn.

Question 21

how is buccal and labial moulding achieved

Answer 21

moulding for both the maxillary and mandibular impressions, it is achieved by supporting the tray with one hand while manipulating the cheeks and lips with the other

Question 22

when you have taken the impression how is it assessed

Answer 22

 Those sulcus areas which will be related to the denture borders
 The edentulous area
 The teeth

Question 23

how should impressions be treated

Answer 23

they should be rinsed and disinfected

Question 24

how is the impression prevented from drying

Answer 24

by covering it with a damp napkin and placing it in a plastic bag

Question 25

what should the lab instructions be sent with the primary impressions

Answer 25

1. Details of the patient and the dental practice 2. Confirmation that the clinical items have been disinfected 3. Date of the next appointment 4. A request for the study cast to be surveyed if required 5. Request for wax occlusal rims where necessary, if mounting of the study casts on an articulator required to assist in the RPD design stage 6. Specification of material and design of the individual impression trays 7. Size and location of ay stops to be performed on the tray

Question 26

what is the normal bite

Answer 26

the intercuspal position

Question 27

when can casts be hand articulated

Answer 27

when it is obvious where the teeth meet

Question 28

what is not needed when the casts can be hand articulated

Answer 28

you do not need a primary record block and do not need to record the occlusion you can get the casts mounted on the articulator with a wax wafer or nothing at all

Question 29

how can the interocclusal record be done in visit 1

Answer 29

using a wax wafer | The wax is warmed and the patient bites on it.

Question 30

why should you see the teeth meeting in a wax wafer

Answer 30

you will create a space.

Question 31

when can a cast not be hand articulated

Answer 31

when there is a free end saddle

Question 32

what is required if the cast cannot be hand articulated

Answer 32

record the occlusion using a primary record block and ask the technician to mount the primary cast using you registration

Question 33

how is the master impression material decided

Answer 33

undercuts - requires more elastic material

Question 34

what is the lab instruction for a hand articulated

Answer 34

pour primary cast | special tray with spacer (1-2 sheets of wax depending on master impression material with handles/fingers rest)

Question 35

what is the lab instruction for non-hand articulated

Answer 35

pour primary cast special tray with spacer (1-2 sheets of wax depending on master impression material with handles/fingers rest) construct primary record block for preliminary jaw registration - base can be wax, shellac or light cure acrylic

Question 36

how does the accuracy of the material effect the spacing of the special tray

Answer 36

more accurate, less space

Question 37

what do you want done in terms fo the design of the denture before visit 2

Answer 37

 Survey to decide the path of insertion  Survey to decide undercuts ect so you know where to put clasps  Do you need to modify the teeth to produce rest seats, guide planes and undercuts  Draw the design on the lab work card and get it signed of by a clinician

Question 38

what happens in visit 2

Answer 38

master impressions are obtained

Question 39

why do we take a master impression

Answer 39

The production of a cast sufficiently accurate for the construction of an RPD frequently necessitates the use of an individual tray. Such a tray enables an accurate impression to be made of the functional depth and width of the sulci in those areas that will be related to the denture border and to components such as gingivally approaching clasps, connecting bars and plates.

Question 40

what can you do when trying in special trays

Answer 40

you can trim the peripheries if overextended and modify the peripheries with greenstick and fit surface for free end edentulous saddles

Question 41

what are the impression materials at the GDH

Answer 41

poly vinyl siloxane polyether alginate impression compound

Question 42

what is poly vinyl siloxane

Answer 42

o Brand name = extrude o Medium body o Be careful how much material you put in as it could be swallowed, and it is not biodegradable o Dimensionally stable

Question 43

what is polyether

Answer 43

o Brand name = impregum o It is very rigid – do not use with undercuts o Also be careful with patients who have periodontal disease as you do not want it to get stuck o Dimensionally stable

Question 44

what is alginate

Answer 44

o Well mixed o Poured up as soon as possible o Good if undercuts are present o Be careful for air blows – it can compromise the accuracy

Question 45

what are the instructions for the technician after visit 2 if you want cobalt chrome

Answer 45

pour model in improved stone construct chrome framework per design clear design signed by clinical REMEMBER TO PREPARE OCCLUSAL RESTS/GUIDE PLANES BEFORE TAKING IMPRESSION

Question 46

what are the instructions for the technician after visit 2 if you want acrylic

Answer 46

pour model in stone | construct record block with shellac base

Question 47

what does visit 3 consist of

Answer 47

framework trial | recording occlusion

Question 48

why should the framework trail be done without the addition of wax rims or artificial teeth

Answer 48

if the casting does not fit into place at once, the presence of wax hinders the search for interferences and additionally if the cast needs adjustment with stones, the heat generated may melt the wax and if the casting needs adjustment with stones the heat generated may melt the wax

Question 49

what questions do we need to ask when doing a trial fit on the cast

Answer 49

 Does it fit the cast?  Does it seat correctly in the mouth?  Is the cast damaged?  Is the framework interfering with the occlusion

Question 50

how can we adjust the framework at chair side

Answer 50

(wearing appropriate mask for chrome adjustments) and using adam’s pliers for clasps

Question 51

why do we need to record occlusion

Answer 51

 To help design the denture  To help the technician set up the teeth  To ensure the denture is stable and is not dislodged in function  Patient comfort  Ensuring loading forces applied correctly to teeth

Question 52

what are the two approaches when it comes to occlusion

Answer 52

conformist | reorganized

Question 53

what is the conformist approach

Answer 53

this is when we keep the occlusion the same as it currently is. We need to know the position of the teeth in relation to each other.

Question 54

what is the reorganized approach

Answer 54

this is when we alter the occlusion either because of tooth wear or there is not enough teeth to meet

Question 55

what is the aim of visit 3

Answer 55

establish the inter-occlusal relationship to articulate the casts, occlusal vertical dimension and the tooth shade and mould.

Question 56

what extended edentulous spaces do we want to establish

Answer 56

 Buccal/labial contours of wax record block  Lip support  Incisal plane  Posterior plane

Question 57

what are you aiming to inform the technician in visit 3

Answer 57

You are aiming to inform the technician where you want the artificial teeth to be positioned, their shade and mould, together with information on how the teeth occlude.

Question 58

what do we use for definitive occlusal registration

Answer 58

wax occlusal rims | they are made on casts from the master impression

Question 59

what do we need to do if there are no index teeth

Answer 59

we need to measure the occlusal vertical dimension (OVD) and the freeway space (FWS).

Question 60

how do we measure OVD and FWS

Answer 60

Willis bite gauge measure the vertical dimension – the first is when the patient is biting together and the second is when the patient is at rest. Sitting at rest the patient should have at least 2/3mm between their teeth at rest. The difference is called the freeway space. It is more important in complete dentures as in RPD the patient has teeth and we try to conform to that.

Question 61

what can be used to find the initial starting point for the oVD

Answer 61

old dentures

Question 62

why do we need to trim the wax blocks

Answer 62

Trim the blocks – when you try the blocks in they will be bulky. It has to stay in place. Any overextension of the peripheries will drop/displace. Too much lip support and it will drop. You use a wax knife and hot plate/spatula to make adjustments. Adjust the upper rim first. You may need to adjust the rim labially/buccally.

Question 63

why do we need to check the wax occlusal rims

Answer 63

The wax occlusal rims may be placed on temporary bases of shellac or acrylic resin or on the definitive cast metal frameworks. These must be tried in the mouth and their stability checked. If the stability is poor, yet the baseplate fits the cast accurately, consideration must be given to the possibility that the problem is due to an inaccurate impression. If this is confirmed the working impression must be retaken. The retention of the occlusal rim must be sufficient to maintain then rim in position during subsequent recording procedures.

Question 64

when prescribing the position of anterior teeth what do we need to do

Answer 64

1. Make sure index teeth (teeth that already bite together) in occlusion 2. Mark centerline 3. Correct incisal plane 4. Correct antero-posterior position

Question 65

what are the reference points for positioning of anterior teeth

Answer 65

```  Teeth present  Dento-facial midline  Inter-pupillary line  Ala-tragus line  Curvature of lower lip  Smile line  Gingival margins of existing anterior teeth  Previous dentures ```

Question 66

how should you select shade

Answer 66

think about existing teeth, previous denture and patient preference

Question 67

how should you select mould

Answer 67

you need to compare to existing teeth, previous denture and also measure

Question 68

what should you say to the technician after visit 3 for the record block on the framework

Answer 68

construct wax record blocks on framework (additional visit required)

Question 69

what should you say to the technician after visit 3 for the tooth trial

Answer 69

articulate casts for registration | set teeth for wax trial (shade and mould provided)

Question 70

what is visit 4

Answer 70

tooth trial

Question 71

what do we check in visit 4

Answer 71

``` We need to check:  Framework fit  Occlusion  Aesthetics  Extension ```

Question 72

what is the lab instruction after visit 4

Answer 72

please take to finish in acrylic (if happy)

Question 73

what is visit 5

Answer 73

delivery

Question 74

what happens when the denture is made in acrylic

Answer 74

You do get small dimensional changes when you make the denture in acrylic – sometimes the fit will improve

Question 75

what is the first thing you do in visit 5

Answer 75

First look at the dentures on the articulator

Question 76

what do you look at in the denture on the articulator

Answer 76

 Check design again is as requested  Examine denture for roughness/blebs – run fingers over acrylic to check for roughness  Check it seats properly  Look at the undercuts and if there are clasps there – are they engaging it? Are they staying in or are they easy to remove? Are any teeth on the cast broken?  Is the pin on the table?  Does the occlusion look correct

Question 77

what do you check when the denture is in the patients mouth (visit 5)

Answer 77

 Stability – does it rock?  Support – are rests/flanges seating accurately  Retention – adjust clasps with adams pliers  Aesthetics – carry out above checks first, last thing you do is show the patient

Question 78

what do you look at when checking the occlusion in the patients mouth

Answer 78

 Do the teeth meet in the prescribed occlusal scheme per the wax up? Check with articulating paper for heavy/early deflective contacts  Is something propping open the bite? Small change adjust with acrylic bur chairside. Large change may require removal of teeth and reset in wax.

Question 79

what are the instruction given to patient based on

Answer 79

```  Insertion/removal  Coping with new dentures  Pain  Denture cleansing  Speech  Eating  Refer to clinic patient information leaflet ```

Question 80

what is visit 6

Answer 80

The review | Here we take a history, do an examination and make any adjustments