6 Prosthodontics

Kennedy classification:


Tooth mould:

Cawood classification:

Assessment:
• Hx, exam and assessment of tooth
• Decide whether want PFM; Lithium Disilicate (EMax); Monolithic Zirconia; or Gold
• PA radiograph
• Dx wax-up, aiming to achieve normal tooth contours
• Occlusal ssessment, so to achieve normal tooth contours, do other teeth need to be adjusted?
• Tx planning
• Preparation key(s) and Special tray

• Refined tooth preparation so the tooth preparation is completed according to the relevant preparation guidelines

• Bite registration
• Tray adhesive
• Mix putty, and take impression
• Measure out 2 level scoops of alginate material
• Measure out 2 scoop level for water
• Mix in silicone mixing bowl w/ spatula, and take impression
• Soak all impressions in diluted Miltons solution
• Store in plastic box, w/ Lab form

Occlusal splint

• Primary impression, so alginate impressions of both arches that include all relevant anatomy for construction of a special tray
• Secondary impression, so PVS impression of the relevant arch using a special tray. The secondary impression should be preceded by recontouring and polishing of restorations to improve the fit of the occlusal splint. Also, Jaw registration, so it's needed w/ the mandible recorded in the same vertical and horizontal position as it will be w/ the occlusal splint in place. E.g. an anterior leaf gauge may be used to place th emandible in centric relation w/ the posterior teeth at least 2mm apart for minimum splint thickness
• Occlusal splint insertion, so (1) Check the fit and retention of the occlusal splint and adjust if necessary; (2) Use to check and adjust the occlusal contacts w/ the mandible in centric relation; (3) Use 12um articulation foil to check and adjust the protrusive and excursive movements of the mandible; (4) Show the Pt how to insert and remove their new occlusal splint; and (5) Provide the Pt w/ verbal and written instructions on the frequency of use, splint care, r/v periods, etc
• Occlusal splint r/v and adjustment, so Has the Pt worn their occlusal splint in according to directions and if not why not; Has the Pt's Sx's improved or changed; Repeat the 1st 3 Ix's of the insertion appointment to check the occlusal splint; Adjust the occlusal splint if necessary; and Determine if and when a f/u r/v appointment is needed
• Repeat occlusal splint review/adjustment as required

Complete denture steps:

• Clinic: Hx and exam, Tx plan; Primary impressions
• Lab: Pour impressions for primary casts; Construct special trays (our task)
• Clinic: Final impressions (border moulding w/ green stick), so for Complete dentures using ZOE impression w/ appropriate pressure relief and border extensions
• Lab: from final impressions, will pour final impression and provide occlusal registration rims. Complete dentures need bite rims that are shaped and connected to comms to the dental technician a # of parameters inc the midline, anterior tooth position, and occlusal vertical dimension. To facilitate this process, a face-bow record may be taken to relate the maxillary model to the dental articulator
• Clinic: Record jaw relations, using fox plane in bite, ensuring that it is parallel w/ a ruler resting on the Pt's interpupillary line, and ala-tragus line. Use Willis gauge to measure. Check occlusion, physiologic rest position is when lips just barely touch. Occlusal vertical dimension is when teeth touch. Adjust rim until difference between these are 2-4mm
• Lab: Set up teeth and continue w/ remaining lab processes
• Clinic: Try-in of dentures
• Lab: Process and finish complete dentures
• Clinic: Insert complete dentures
• Clinic: Post insertion check

Metal (CoCr) RPD's:

• Clinic: Hx, exam, and overall Tx plan, so whether mouth is ready. Primary impressions, so alginate (or compound) impressions of both arches include all relevant anatomy for prosthetic planning and construction of special trays. Also, Record jaw relations if insufficient opposing teeth to articulate primary casts
• Lab: Survey primary/Dx casts/models, so determining path of insertion, and clasp position; Construct occlusal/jaw registration rims and special trays (our task); Mount Dx casts on articulator for analysis. Then, design partial dentures on separate denture design sheet, so determine the position and type of guide-planes, clasps, and rest seats, the major connector type, + the need for mouth preparation
• Clinic: Drilling of pre-determined tooth modifications in mouth if required; and Final/Secondary impressions w/ PVS impression
• Lab: Based on final impression, lab will pour final impression and Survey master cast, construct the CoCr metal framework
• Clinic: Try-in of metal framework/cast. Addition of pink wax, for eventual setting of teeth. Also, record jaw relations, where criss-cross grooves are made on the occlusal surface of the wax, universal adhesive is applied, and bite registration is taken on top; jaw relations are needed when the relationship between the Mx and Md models is not obvious
• Lab: Set up teeth and continue w/ remaining lab processes
• Clinic: Try-in of denture, so use denture checklist to sign off that all areas of aesthetics/ponetics/occlusion have been covered
• Lab: Process and finish RPD
(• Clinic: Repeat try-in as necessary)
• Clinic: Insert RPD, where the codes are put through
• Clinic: Post insertion check, and adjustment

Acrylic RPD's:

• Clinic: Hx and exam, Tx plan; Primary impressions. Also, Jaw relations if insufficient teeth to articulate the primary casts
• Lab: Survey primary/Dx casts. Mount Dx casts on articulator for analysis, though in some cases may not be required. Lab will Design dentures
• Clinic: Tooth modifications are often not required. And Final impressions; and Jaw relations
• Lab: Final impression is set to lab w/ RPD design prescription
• Clinic: Try-in of denture (set-up of teeth)
• Lab: Process and finish RPD
• Clinic: Insert RPD
• Clinic: Post insertion check

To adjust occlusal surface:
• Bite paper
• Slow speed w/ straight handpiece to adjust denture

To adjust clasp:
• Using pliers, only adjust terminal 1/3rd of the clasp, that engages the undercut, and touches the tooth
• Repeat until satisfied w/ undercut engagement

• Heat mouth guard posterior section w/ butane gas
• Get Pt to bite down
(Repeat)

• Wet impression
• Place water in bowl
• Mix in stone powder, until when fails to droop
• On vibrator, run mix slowly through, seeing that all gaps fill
• Place filled impression on top of base

• Grind down stone model
• Quick cutter to remove stone where excessive

• Place water in bowl
• Mix in plaster powder, until when fails to droop; slightly more thicker than for pouring stone
• Dab mix on to articulater plates, place stone models in bite on top
• Use plaster knife to tidy, fingers, toothbrush, and brush as necessary
• Repeat for opposing model

• Remove models from articulator to tidy using sandpaper

• Use pencil to design extensions
• Place pink wax over model, and trim to extensions
• Place another pink wax bit to reinforce over teeth
• Cut out circular stops, at 4 distributed high points, 2 on either side
• Push a bit of acrylic into the stops
• Overlay acrylic over the wax
• Cure using UV light
• Melt pink wax away w/ hot water
• Use stone cutter to cut down
• Bur to smoothen

• Remove models from articulator
• Place models on to surveyor
• Alter angulation to minimize undesirable undercuts
• Using pencil, draw lines around every tooth
• Record 3 locations intraorally to re-establish position later

• Transfer design on to the paper form

• Place acrylic over teeth, and cut back to around teeth as necessary
• Place strengthening wire over main body of acrylic for strengthening
• Create ball clasps for clasping around teeth on either side
• Place pink wax to smoothen, as well as on top of teeth area, for easy melting in the clinic

• Don't need model w/ base, trim excess from model
• (Add pink wax on to labial surface of teeth)
• Select soft bleaching tray sheet, and clamp into place
• Start heat
• Turn off heat, and clamp down on to the cast
• After few mins turn off vacuum
• Let tray cool down before retrieving the model
• Mark gingival margin on facial surface, as reference when cutting tray

• Tell Pt just to add drop of bleaching gel on to the facial surface

Dispensing of SDI Polanight:

• Ensure impression has full depth of labial sulcus
• Thin base on model, opening up the palate
• Select color of mouthguard
• Place material on vacuum forming machine, close down top part of device, lock in place
• Raise tray, and turn heater on
• Turn on vacuum, and lower tray
• Open tray, remove from vacuum forming machine
• Rough trim using heated scalpel, w/ border around 3mm short of sulcus
• 45 degree bevel all the way around mouthguard
• Flame the border, not attempting to flame too much at a time
• Ensure relief around frenum

• Block out extreme undercuts esp if making hard splint
• Articulate models on quick articulator
• Open bite so molars, and canine rise are cleared
• Take apart then thermoform
• Heat
• Suck down
• Take out
• Put separator on adjacent model
• Build up, separately, and then whilst articulating against adjacent model
• Cure appliance in pressure pot
• Articulating paper
• Grind out
• Pumice and polish