Flow chart on Complete denture fabrication

Complete denture fabrication is an integral part of postgraduate examination in prosthodontics. Various steps to be followed in examination are included in the list that follows. It is arranged in the form of a flow chart. One who follows these steps meticulously, can easily get predictable results.

1.Examination of the patient

-medical history

-common diseases

-drugs in use

-investigations to be conducted

-dental history

-making a record

-reason for loss of teeth

-clinical examination of the mouth

-mounted casts

-radiographic examination

-OPG/Ceph

-signing a consent

-treatment plan

-different options

-conventional

-implant integrated

-different materials

 

2.Impressions

-preliminary impression

-stock tray

-silicone putty/light body combination

-cast prepared in dental plaster

-custom tray prepared in acrylic resin

-final or secondary impression

-custom tray

-border moulding with silicone putty modified with vaseline

-lining with light body

-boxing of impression

-cast prepared in dental stone

 

3.Permanent bases made in heat cure acrylic resin

-pattern made in shellac base plate and modeling wax

-flasked, dewaxed,packed, processed

-finishing of the bases

-undercut blocked in Vaseline and cast poured in dental stone

-removal of the cast, washing and drying

-borders of the bases should maintain intimate contact with the repoured cast

 

4.Jaw relations

-preparation of occlusion rims in modeling wax

-maxillary, anterior height 22mm, posterior height 8mm,

-width anterior/premolar/molar – 5/6/7mm

-mandibular, anterior height 18mm, posterior to the level of half of retromolar pad

-width anterior/premolar/molar – 5/6/7mm

-modification of occlusion rims to acceptable vertical height

-symmetric arch

-maxillary occlusal plane parallel to

-ala-tragal line

-inter pupillary line

-perpendicular to midline

-verification with Fox’s occlusal plane indicator

-mandibular rim at the level of

-dry-wet junction of lower lip

-angle of the mouth

-mid point of the retromolar pad

-close apposition of both the rims

-midline marking, canine line marking

-tubercle of philtrum helps midline marking

-nose width while smiling helps canine line marking

-4mm free way space

-closest speaking space 1mm

 

 

5.Face bow transfer

-Hanau spring bow and fork

-fork tip to be flattened gently

-fork heated gently to pierce the maxillary rim

-parallel to occlusal plane, 3mm above

-fork midline and occlusion rim to be matched

-nob of the fork to face towards the denture base

-mark the midline of the maxillary base on the tissue surface

-yoke of the bite fork and the mid line to be made parallel

-reinforcement of attachment with sticky wax

-place the maxillary rim with the fork in the mouth

-verify coincidence of facial midline with

-occlussion rim midline

-fork midline

-insert the mandibular occlusion rim to support maxillary rim

-verify yoke position

-viewed from top of the head, parallel to mid sagittal plane

-viewed from side, parallel to ala tragal line

-fix the transfer rod having clutches to the face bow

-insert the yoke through the hole of the cluthes

-slide the face bow and turn it down to position the ear piece nobs into auditory  meatus

-verify the position of the spring bow

-parallelism to yoke of the fork, viewed from front

-orbitale indicator to match with orbitale marked on skin

-face bow horizontality with spirit level placed on the face bow

-head can be moved so that horizontality can be ensured

-tighten the screws 1,2,3 of the transfer rod assembly

-release the transfer rod from the spring bow by loosening the thumb screw

-ask the patient to open the mouth

-release the transfer rod with the fork and base assembly

-fix the transfer jig to the lower member of the hanau wide vue articulator

-fix the support rod assembly to the transfer jig

-fix the transfer rod assembly to the transfer jig and tighten the thumb screw

-tighten the centric lock

-adjust the incisal pin at zero position

-verify whether the midline marked on the denture base

-matches with the mid line of the upper member of the articulator

-keep the upper member in open position

-mark the midline with a pencil

-adjust the support rod to touch the occlusion rim

-fix the maxillary mounting ring

-keep the cast and close the upper member

-verify the space availability between upper member and cast for

-split cast, mounting plaster

 

6.Split cast

 

-base of maxillary cast trimmed perfectly flat

-make four shallow notches of 3mm depth

-two towards the anterior region

-two towards the posterior region

-use a round tipped conical tungsten carbide trimmer

-with modeling clay fix the cast, base facing upward on a glass plate

-make the base perfectly horizontal

-verify horizontality with spirit level

-apply separating medium on the base of the cast

-box the cast with modeling wax

-3mm above the cast base make two perforations in the wax box

-pour mixed die stone and vibrate with a brush

-die stone thickness should be limited to the perforations on the wax box

-after setting, box is removed, an elongated hole is drilled

-at the junction of the split

-at the posterior base of the cast

-insert a small screw driver and twist

-split will be separated

-staple pins will be fixed on the top surface of the split cast

-holes drilled with bur

-fix staples with super glue

-staples will aid in holding on to the mounting plaster

-mount the upper cast

 

 

 

7.Mount the lower cast

                               

-follow the steps in ( 4 )

-seal the maxillary and mandibular rims with staple pins

-seal the rims outside the mouth with heated instrument

-place the rims on the upper cast

-keep the articulator upside down

-place the lower cast

-place mounting plaster

-make sure that mounting rings are firmly placed

-make sure 3mm clearance between the bases/casts in the heal region

-in centric and eccentric positions

 

 

8.Fixing the central bearing plates

 

                                -reduce the mandibular occlusion rim height

-4mm

-parallel walled space between the occlusion rims

-fix the central bearing point by counter sinking

-the surface of rim and the plate should be same

-fix the maxillary central bearing plate by counter sinking

-the central bearing plate – resin base junction should be reinforced with sticky wax

-this will prevent sinking of the central bearing plates during tracing

-adjustable central bearing point in the lower base is raised

-to contact the maxillary central bearing plate

-when the articulator is closed

-incisal guide pin of the articulator is verified for its correct positioning

-place an articulating paper(blue) over the central bearing point

-tap the upper member over it to make a mark on the upper plate

-place both the bases in the mouth

-place an articulating paper(red) over the central bearing point

-ask the patient to close the mouth firmly to make a mark on the upper plate

-the blue mark and the red mark, if coincides

-indicate correctness of centric relation recorded

-otherwise redo centric relation registration

-block the gaps between the metal plates and occlusion rim with wax

-incorporate triangular location notches on the wax rim

-minimum two in each occlusion rim

 

9.Fix the extra oral tracer

 

                                -lower member of the Hight tracer is fixed to the mandibular occlusion rim

-use sticky wax for firmness of the joint

-3mm below the modified occlusal plane

-maintain parallelism

-the tracing table should not touch any part of the articulator

-the upper member of the tracer is fixed to maxillary occlusion rim

-3mm above the occlusion plane

-parallel to lower member of tracing unit

-use sticky wax

-the stylus should just touch the tracing table

-find out whether the stylus can move vertically under the spring load

-no heavy pressure exerted by the stylus

 

 

10.Tracing

 

-place both the bases in the mouth

-smear the surface of the maxillary plate with Vaseline

-coat the tracing table with a mix of zinc oxide(DPI) and spirit

-mix in a dappen glass

-use a flat brush no.5

-apply with single strokes

-allow it to dry

-ask the patient to close the mouth in centric

-repeat three times

-ask the patient to protrude and go back without any restriction

-do not insist on straight lines

-slowly the patient will learn

-repeat minimum ten times

-tap on the right shoulder of the patient and

-ask him to move the jaw to the right and come back

-repeat ten times

-similarly do it on the left side

-give training till you get an arrow point tracing

-three lines meeting at a point

-point designates centric relation

-the lines represent mandibular border movements

-mark a point 6mm away from the centric on the protrusive line

-use a small divider with metal points for marking

-zinc oxide coating should be thin but with contrast

-never apply on previous coating

 

11.Records

 

-place a transparent plastic sheet over the tracing gently

-mark on it the centric and 6mm protrusive point

-convert the marking into holes with tapered diamond bur

-the hole should hold the stylus

-fix the plastic sheet on the tracing table with sticky wax or super glue

-place the maxillary base with the tracer in the mouth

-place mixed accelerated plaster/dental stone on the mandibular central bearing plate

-place it in the mouth

-guide the lower jaw so that the stylus slides into the centric perforation

-excess material can be wiped with a brush or tissue

-wait till the plaster sets

-carefully remove the bases with plaster record from the mouth

-hold it below the tap and separate the record

-gently trim the borders of the record

-make another record in the protrusive position in a similar way

 

12.Programming the articulator-horizontal angle

 

-programming is done in four phases

-transferring the relation of inter condylar axis to maxilla

-transferring maxillo-mandibular relation

-adjusting the horizontal condylar path

-adjusting the inclination of the incisal guide table

-first two phases are completed through the previous stages

-for adjusting the horizontal condylar path the plaster records are used

-on each side of the mandibular and maxillary cast fix pins

-four pins in the maxilla and four in the mandible

-of the four pins two should be in the front of central bearing point

-and two behind

-die pins can be fixed in drilled holes with super glue

-raise the stylus of the tracing unit and lock

-place the centric record on the mandibular occlusal rim

-place the maxillary occlusal rim and the cast over it

-check for stability of the assembly

-holding the assembly firmly, the four pins of each side

-to be tied with a thread

-this will stabilize the assembly below the split

-close the upper member to approximate the split

-notches will help in precisely locate the split

-desirable to loosen the centric lock

-the split should obliterate completely

-the condylar sphere should rest against the stop

-matching the check bite centric and graphic centric is thus verified

-disassemble the casts and the centric record

-position the protrusive record and make the assembly

-as described in centric

-close the upper member to obliterate the split

-move the condylar track assembly till the split is completely obliterated

-the horizontal angle is thus adjusted

-both the condylar spheres will be away from the centric stop

-bennet angle is set by the formula (H/8)+12

-condylar path is thus adjusted

 

 

 

13.Programming the articulator- adjusting the inclination of the incisal guide table

 

-arrange the maxillary anterior teeth

-verify aesthestics, midline coincidence, visibility on smile

-verify phonation

-pronounce f and v

-incisal edges of maxillary teeth makes a contact with

dry wet junction of lower lip

-arrange mandibular teeth

-with 2mm horizontal and 2mm vertical overlap

-keep the incisal guide table horizontal

-loosen the centric lock

-push the incisal guide pin backward till the incisors make a tip to tip contact

-tighten the centric lock in that position

-incisal pin will be in a raised position

-incisal guide table will be adjusted to touch the pin in the protrusive position

-note the angulation of the table

-desirable inclination is 5o

-if it is more than 5o rearrange the lower anteriors

-after the above step, move the incisal pin till the canines make a tip to tip contact

-tighten the centric lock it in that position

-raise the lateral wing of the incisal table to touch the incisal pin

-tighten the lock below the lateral wing

-repeat the same exercise on both sides

-programming the articulator is complete

 

14.Arranging the posterior teeth

 

-position the first molars in occlusion in an approximated position matching the    occlusion rim

-try protrusive movement

-maxillary and mandibular incisors should come into contact

-maxillary and mandibular molars should make contact

-if not raise the molar unit, 1mm above the occlusal plane

-retry the protrusive movement

-repeat the process till balancing contact is obtained with molars

-this will decide the orientation of the occlusal plane

-arrange all the posterior teeth according to the decided occlusal plane

-check the occlusal contact with articulating paper

-marks should be present on the following maxillary teeth

-mesial marginal ridge of the first premolar

-palatal cusp of the second premolar

-mesio palatal cusp of the first and second molar

-marks should be present on the following mandibular teeth

-buccal cusp of the first premolar

-distal marginal ridge of the second premolar

-central fossa of the first and second molar

 

-once the essential contacts are achieved excursive movements can be tried

-upper member of the articulator (Hanau wide vue) pushed to the left

-right side becomes working

-left side becomes balancing

-right side maxillary palatal cusps move on the buccal slopes of the lingual cusps of mandibular posteriors

-verify this with articulating paper

-left side (balancing) maxillary palatal cusps move on the lingual slopes of the buccal cusps of the mandibular posteriors

-verify this with articulating paper

-the markings should be of similar intensity

-if not grind gently on the marking

-never grind the holding cusp or else vertical height will decrease

-reverse this process by making left side working and right side balancing

-gently grind the palatal slopes of the buccal cusps of maxillary teeth

-this will smoothen the excursive movements

-when the sides are reversed, articulating paper colour should be changed

-try this in patient

-make sure the centric matches with intercuspation

-make sure there is anterior horizontal and vertical overlap

-after protrusive and lateral excursions, maxillary anteriors should not loosen from the base

 

15.Process the dentures one by one

-when one denture is processed, do lab remount against the other

-do corrections in the articulator

-process the other denture

-do lab remount and do corrections in the articulator

-correction for vertical height changes if any

 

16.Try dentures in the patient

 

17.Do clinical remount (optional)

 

18.Follow up and evaluations

 

 

 

 

 

 

 

 

 

 

 

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