Preliminary Edentulous ImpressionsPreliminary Edentulous ImpressionsPreliminary Edentulous ImpressionsPreliminary Edentulous Impressions

Preliminary Edentulous ImpressionsPreliminary Edentulous ImpressionsPreliminary Edentulous ImpressionsPreliminary Edentulous Impressions

Preliminary impressions Preliminary impressions needed for diagnostic casts for needed for diagnostic casts for making custom traysmaking custom trays

Preliminary impressions Preliminary impressions needed for diagnostic casts for needed for diagnostic casts for making custom traysmaking custom trays

Custom TrayCustom TrayCustom TrayCustom Tray

Required to accurately register Required to accurately register moveable mucosamoveable mucosa

Create seal for retentionCreate seal for retention

Required to accurately register Required to accurately register moveable mucosamoveable mucosa

Create seal for retentionCreate seal for retention

Stock TraysStock TraysStock TraysStock Trays

Stock trays can result in Stock trays can result in distortion and shortening of the distortion and shortening of the final denture flangefinal denture flange

Stock trays can result in Stock trays can result in distortion and shortening of the distortion and shortening of the final denture flangefinal denture flange

Alginate Syringe TechniqueAlginate Syringe TechniqueAlginate Syringe TechniqueAlginate Syringe Technique

Irreversible hydrocolloidIrreversible hydrocolloid Ensures capture of critical Ensures capture of critical

anatomy - sometimes missed anatomy - sometimes missed with just a traywith just a tray

Irreversible hydrocolloidIrreversible hydrocolloid Ensures capture of critical Ensures capture of critical

anatomy - sometimes missed anatomy - sometimes missed with just a traywith just a tray

Border MoldingBorder MoldingBorder MoldingBorder Molding

Minimizes distortion of the Minimizes distortion of the movable vestibular tissuesmovable vestibular tissues

Displacement could lead to Displacement could lead to dislodgment during functiondislodgment during function

Minimizes distortion of the Minimizes distortion of the movable vestibular tissuesmovable vestibular tissues

Displacement could lead to Displacement could lead to dislodgment during functiondislodgment during function

Irreversible Hydrocolloid StorageIrreversible Hydrocolloid StorageIrreversible Hydrocolloid StorageIrreversible Hydrocolloid Storage

Pre-weighed pouches Pre-weighed pouches – Easier dispensingEasier dispensing– Minimizes contaminationMinimizes contamination

Bulk material Bulk material – Store in cool dry airtight Store in cool dry airtight

containerscontainers

Pre-weighed pouches Pre-weighed pouches – Easier dispensingEasier dispensing– Minimizes contaminationMinimizes contamination

Bulk material Bulk material – Store in cool dry airtight Store in cool dry airtight

containerscontainers

Irreversible Hydrocolloid Storage Irreversible Hydrocolloid Storage Irreversible Hydrocolloid Storage Irreversible Hydrocolloid Storage

Deteriorates if: Deteriorates if: – Stored above 54°CStored above 54°C– Repeated openingsRepeated openings

Deterioration results in: Deterioration results in: – Thin mixturesThin mixtures– Reduced strengthReduced strength– Permanent deformationPermanent deformation

Deteriorates if: Deteriorates if: – Stored above 54°CStored above 54°C– Repeated openingsRepeated openings

Deterioration results in: Deterioration results in: – Thin mixturesThin mixtures– Reduced strengthReduced strength– Permanent deformationPermanent deformation

Tray SelectionTray SelectionTray SelectionTray Selection

5 mm of clearance 5 mm of clearance with soft tissueswith soft tissues

Hydrocolloid requires Hydrocolloid requires bulk for accuracy, bulk for accuracy, strength and stabilitystrength and stability

5 mm of clearance 5 mm of clearance with soft tissueswith soft tissues

Hydrocolloid requires Hydrocolloid requires bulk for accuracy, bulk for accuracy, strength and stabilitystrength and stability

Tray SelectionTray SelectionTray SelectionTray Selection

Maxillary trays should extend Maxillary trays should extend slightly beyond vibrating lineslightly beyond vibrating line

Mandibular trays should cover Mandibular trays should cover the retromolar padsthe retromolar pads

Maxillary trays should extend Maxillary trays should extend slightly beyond vibrating lineslightly beyond vibrating line

Mandibular trays should cover Mandibular trays should cover the retromolar padsthe retromolar pads

Tray SelectionTray SelectionTray SelectionTray Selection

Sto-K edentulous traysSto-K edentulous trays Short flanges, so donShort flanges, so don’’t distort t distort

vestibulevestibule

Sto-K edentulous traysSto-K edentulous trays Short flanges, so donShort flanges, so don’’t distort t distort

vestibulevestibule

Tray ModificationTray ModificationTray ModificationTray Modification

Trays can be modified with Trays can be modified with compound to extend the tray if compound to extend the tray if desireddesired

Trays can be modified with Trays can be modified with compound to extend the tray if compound to extend the tray if desireddesired

Irreversible Hydrocolloid Syringe TechniqueIrreversible Hydrocolloid Syringe TechniqueIrreversible Hydrocolloid Syringe TechniqueIrreversible Hydrocolloid Syringe Technique

Critical anatomy registrationCritical anatomy registration– Retromylohyoid areaRetromylohyoid area– Hamular notchesHamular notches– Retrozygomal areaRetrozygomal area

Critical anatomy registrationCritical anatomy registration– Retromylohyoid areaRetromylohyoid area– Hamular notchesHamular notches– Retrozygomal areaRetrozygomal area

Patient PreparationPatient PreparationPatient PreparationPatient Preparation

Practice placing trayPractice placing tray Rotate into placeRotate into place

Practice placing trayPractice placing tray Rotate into placeRotate into place

Patient PreparationPatient PreparationPatient PreparationPatient Preparation

Dry the mucosaDry the mucosa– Dry the maxilla with folded gauzeDry the maxilla with folded gauze– Pack 3 gauze in mandiblePack 3 gauze in mandible– DonDon’’t let patient closet let patient close

Dry the mucosaDry the mucosa– Dry the maxilla with folded gauzeDry the maxilla with folded gauze– Pack 3 gauze in mandiblePack 3 gauze in mandible– DonDon’’t let patient closet let patient close

Mark Vibrating LineMark Vibrating LineMark Vibrating LineMark Vibrating Line

Prior to making Prior to making preliminary & final preliminary & final impressionsimpressions

Fovea should not be usedFovea should not be used

Prior to making Prior to making preliminary & final preliminary & final impressionsimpressions

Fovea should not be usedFovea should not be used

Vibrating LineVibrating LineVibrating LineVibrating Line

If denture terminates anteriorly, If denture terminates anteriorly, poor seal poor seal

If terminates posteriorly, soft palate If terminates posteriorly, soft palate movement may cause it to dislodgemovement may cause it to dislodge

Denture may be unretentive and/or Denture may be unretentive and/or uncomfortableuncomfortable

If denture terminates anteriorly, If denture terminates anteriorly, poor seal poor seal

If terminates posteriorly, soft palate If terminates posteriorly, soft palate movement may cause it to dislodgemovement may cause it to dislodge

Denture may be unretentive and/or Denture may be unretentive and/or uncomfortableuncomfortable

Locate & Mark the Hamular NotchLocate & Mark the Hamular NotchLocate & Mark the Hamular NotchLocate & Mark the Hamular Notch

Posterior border of a Posterior border of a complete denturecomplete denture

Between the bony Between the bony tuberosity & hamulustuberosity & hamulus

Posterior border of a Posterior border of a complete denturecomplete denture

Between the bony Between the bony tuberosity & hamulustuberosity & hamulus

Locate & Mark Hamular NotchLocate & Mark Hamular NotchLocate & Mark Hamular NotchLocate & Mark Hamular Notch

Denture border must terminate on Denture border must terminate on soft displaceable tissuesoft displaceable tissue

Provides comfort and retentionProvides comfort and retention Notch may be posterior to Notch may be posterior to

depression in soft tissuedepression in soft tissue

Denture border must terminate on Denture border must terminate on soft displaceable tissuesoft displaceable tissue

Provides comfort and retentionProvides comfort and retention Notch may be posterior to Notch may be posterior to

depression in soft tissuedepression in soft tissue

Locate & Mark the Hamular NotchLocate & Mark the Hamular NotchLocate & Mark the Hamular NotchLocate & Mark the Hamular Notch

Use the head of a Use the head of a mirror, to palpate mirror, to palpate the notchthe notch

Mark with an Mark with an indelible markerindelible marker

Use the head of a Use the head of a mirror, to palpate mirror, to palpate the notchthe notch

Mark with an Mark with an indelible markerindelible marker

Locate Posterior Border of Hard PalateLocate Posterior Border of Hard PalateLocate Posterior Border of Hard PalateLocate Posterior Border of Hard Palate

Ensure the denture Ensure the denture terminates terminates posteriorly by posteriorly by palpatingpalpating

Ensure the denture Ensure the denture terminates terminates posteriorly by posteriorly by palpatingpalpating

Indelible Marks Prior to ImpressionIndelible Marks Prior to ImpressionIndelible Marks Prior to ImpressionIndelible Marks Prior to Impression

Transfer to the impression and Transfer to the impression and cast when it is pouredcast when it is poured

Eliminates errorEliminates error Tissue should be relatively dry Tissue should be relatively dry

to be most effectiveto be most effective

Transfer to the impression and Transfer to the impression and cast when it is pouredcast when it is poured

Eliminates errorEliminates error Tissue should be relatively dry Tissue should be relatively dry

to be most effectiveto be most effective

Syringe PreparationSyringe PreparationSyringe PreparationSyringe Preparation

12 cc disposable syringe12 cc disposable syringe Cut off the tip where it Cut off the tip where it

begins to curve begins to curve 5 mm orifice5 mm orifice

12 cc disposable syringe12 cc disposable syringe Cut off the tip where it Cut off the tip where it

begins to curve begins to curve 5 mm orifice5 mm orifice

Plunger PreparationPlunger PreparationPlunger PreparationPlunger Preparation

Vaseline plungerVaseline plunger Ease of extruding materialEase of extruding material Use:Use:– Uncontaminated bowl, Uncontaminated bowl,

spatulaspatula– Regular set alginateRegular set alginate

Vaseline plungerVaseline plunger Ease of extruding materialEase of extruding material Use:Use:– Uncontaminated bowl, Uncontaminated bowl,

spatulaspatula– Regular set alginateRegular set alginate

Measuring PowderMeasuring PowderMeasuring PowderMeasuring Powder

Fluff (shake) the powder, Fluff (shake) the powder, measure, tap and flatten measure, tap and flatten the scoop with powderthe scoop with powder

Use three scoops for Use three scoops for syringe impressionssyringe impressions

Fluff (shake) the powder, Fluff (shake) the powder, measure, tap and flatten measure, tap and flatten the scoop with powderthe scoop with powder

Use three scoops for Use three scoops for syringe impressionssyringe impressions

Mixing Mixing Mixing Mixing

Assistant mixes for at least Assistant mixes for at least 45 seconds45 seconds

Smooth creamy homologous Smooth creamy homologous mixture that glistensmixture that glistens

Not granular or lumpyNot granular or lumpy

Assistant mixes for at least Assistant mixes for at least 45 seconds45 seconds

Smooth creamy homologous Smooth creamy homologous mixture that glistensmixture that glistens

Not granular or lumpyNot granular or lumpy

Syringe LoadingSyringe LoadingSyringe LoadingSyringe Loading

The assistant loads The assistant loads the syringe nearly the syringe nearly full from the back full from the back and inserts plunger and inserts plunger

The assistant loads The assistant loads the syringe nearly the syringe nearly full from the back full from the back and inserts plunger and inserts plunger

Syringe TechniqueSyringe TechniqueSyringe TechniqueSyringe Technique

Syringe a broad rope into the Syringe a broad rope into the vestibulevestibule

Begin at the posteriorBegin at the posterior Move quickly toward Move quickly toward

anterioranterior Fill the vestibule to labial Fill the vestibule to labial

frenumfrenum

Syringe a broad rope into the Syringe a broad rope into the vestibulevestibule

Begin at the posteriorBegin at the posterior Move quickly toward Move quickly toward

anterioranterior Fill the vestibule to labial Fill the vestibule to labial

frenumfrenum

Cheek RetractionCheek RetractionCheek RetractionCheek Retraction

Use a mirror, Use a mirror, instead of a instead of a fingerfinger

Provides better Provides better visibility, more visibility, more maneuverabilitymaneuverability

Use a mirror, Use a mirror, instead of a instead of a fingerfinger

Provides better Provides better visibility, more visibility, more maneuverabilitymaneuverability

Maxillary ImpressionsMaxillary ImpressionsMaxillary ImpressionsMaxillary Impressions

– Begin opposite the Begin opposite the tuberosity tuberosity

– Inject until alginate is Inject until alginate is seen in the hamular notch seen in the hamular notch before moving forwardbefore moving forward

– Begin opposite the Begin opposite the tuberosity tuberosity

– Inject until alginate is Inject until alginate is seen in the hamular notch seen in the hamular notch before moving forwardbefore moving forward

Mandibular ImpressionsMandibular ImpressionsMandibular ImpressionsMandibular Impressions

Start with the buccal Start with the buccal vestibule adjacent vestibule adjacent retromolar padretromolar pad

Move forward to the labial Move forward to the labial frenumfrenum

Repeat on the opposite sideRepeat on the opposite side

Start with the buccal Start with the buccal vestibule adjacent vestibule adjacent retromolar padretromolar pad

Move forward to the labial Move forward to the labial frenumfrenum

Repeat on the opposite sideRepeat on the opposite side

Lingual VestibuleLingual VestibuleLingual VestibuleLingual Vestibule

Roll syringe tip under tongueRoll syringe tip under tongue Inject into retromylohyoid space Inject into retromylohyoid space

until alginate appears between until alginate appears between tongue & ridgetongue & ridge

Move anteriorly, filling to Move anteriorly, filling to lingual frenumlingual frenum– Repeat on the opposite sideRepeat on the opposite side

Roll syringe tip under tongueRoll syringe tip under tongue Inject into retromylohyoid space Inject into retromylohyoid space

until alginate appears between until alginate appears between tongue & ridgetongue & ridge

Move anteriorly, filling to Move anteriorly, filling to lingual frenumlingual frenum– Repeat on the opposite sideRepeat on the opposite side

Deep Palatal VaultsDeep Palatal VaultsDeep Palatal VaultsDeep Palatal Vaults

Material can be syringed into the Material can be syringed into the palatepalate

Smooth with a finger, or voids Smooth with a finger, or voids may occurmay occur

Material can be syringed into the Material can be syringed into the palatepalate

Smooth with a finger, or voids Smooth with a finger, or voids may occurmay occur

Partially EdentulousPartially EdentulousPartially EdentulousPartially Edentulous

Syringe a small amount of Syringe a small amount of hydrocolloid on the hydrocolloid on the occlusal surfacesocclusal surfaces

Force into the occlusal Force into the occlusal surfaces with fingersurfaces with finger

Syringe a small amount of Syringe a small amount of hydrocolloid on the hydrocolloid on the occlusal surfacesocclusal surfaces

Force into the occlusal Force into the occlusal surfaces with fingersurfaces with finger

Cleaning the SyringeCleaning the SyringeCleaning the SyringeCleaning the Syringe

Preliminary ImpressionsPreliminary ImpressionsPreliminary ImpressionsPreliminary Impressions

The assistant loads the tray The assistant loads the tray while the clinician is while the clinician is syringingsyringing

Place the anterior portion of Place the anterior portion of the tray first, then seat the the tray first, then seat the posterior of the trayposterior of the tray

The assistant loads the tray The assistant loads the tray while the clinician is while the clinician is syringingsyringing

Place the anterior portion of Place the anterior portion of the tray first, then seat the the tray first, then seat the posterior of the trayposterior of the tray

Preliminary ImpressionsPreliminary ImpressionsPreliminary ImpressionsPreliminary Impressions

Less gagging if the patient is lying Less gagging if the patient is lying downdown

Tongue position avoids gaggingTongue position avoids gagging Mold the vestibular areaMold the vestibular area Pull on the cheeks and lips to Pull on the cheeks and lips to

activate muscles and frenaactivate muscles and frena

Less gagging if the patient is lying Less gagging if the patient is lying downdown

Tongue position avoids gaggingTongue position avoids gagging Mold the vestibular areaMold the vestibular area Pull on the cheeks and lips to Pull on the cheeks and lips to

activate muscles and frenaactivate muscles and frena

Finger Sweep at PosteriorFinger Sweep at PosteriorFinger Sweep at PosteriorFinger Sweep at Posterior

If excess material at borderIf excess material at border Use finger or cotton swabUse finger or cotton swab

If excess material at borderIf excess material at border Use finger or cotton swabUse finger or cotton swab

Preliminary ImpressionsPreliminary ImpressionsPreliminary ImpressionsPreliminary Impressions

Support the tray Support the tray during setting - do during setting - do not leave the not leave the patientpatient

Movement causes Movement causes distortiondistortion

Support the tray Support the tray during setting - do during setting - do not leave the not leave the patientpatient

Movement causes Movement causes distortiondistortion

Preliminary ImpressionsPreliminary ImpressionsPreliminary ImpressionsPreliminary Impressions Break peripheral sealBreak peripheral seal– Drops of waterDrops of water– Pull up cheek and let air inPull up cheek and let air in– Wiggle tray until hear seal breakWiggle tray until hear seal break

Break peripheral sealBreak peripheral seal– Drops of waterDrops of water– Pull up cheek and let air inPull up cheek and let air in– Wiggle tray until hear seal breakWiggle tray until hear seal break

Preliminary ImpressionsPreliminary ImpressionsPreliminary ImpressionsPreliminary Impressions

Once seal broken, remove quickly Once seal broken, remove quickly (to avoid permanent deformation) (to avoid permanent deformation)

Evaluate impressionEvaluate impression Pour within 12 minutesPour within 12 minutes

Once seal broken, remove quickly Once seal broken, remove quickly (to avoid permanent deformation) (to avoid permanent deformation)

Evaluate impressionEvaluate impression Pour within 12 minutesPour within 12 minutes

Preliminary Impressions Preliminary Impressions Preliminary Impressions Preliminary Impressions

Rinse thoroughly with waterRinse thoroughly with water Gently shake to remove excess Gently shake to remove excess

waterwater

Rinse thoroughly with waterRinse thoroughly with water Gently shake to remove excess Gently shake to remove excess

waterwater

Preliminary ImpressionsPreliminary ImpressionsPreliminary ImpressionsPreliminary Impressions

Spray with disinfectant to coat Spray with disinfectant to coat all surfaces, and seal in a bag all surfaces, and seal in a bag for ten minutesfor ten minutes

Spray with disinfectant to coat Spray with disinfectant to coat all surfaces, and seal in a bag all surfaces, and seal in a bag for ten minutesfor ten minutes

Sample ImpressionsSample ImpressionsSample ImpressionsSample Impressions

Sample ImpressionsSample ImpressionsSample ImpressionsSample Impressions

Syringe Technique Problems Syringe Technique Problems Syringe Technique Problems Syringe Technique Problems

Vestibular material may not Vestibular material may not join the tray materialjoin the tray material– Saliva contaminationSaliva contamination– Insufficient materialInsufficient material

Vestibular material may not Vestibular material may not join the tray materialjoin the tray material– Saliva contaminationSaliva contamination– Insufficient materialInsufficient material

Syringe Technique ProblemsSyringe Technique ProblemsSyringe Technique ProblemsSyringe Technique Problems

Omitting plunger lubrication Omitting plunger lubrication may make it difficult to may make it difficult to express the alginateexpress the alginate

Trapping tongue under the Trapping tongue under the tray will result in tray will result in underextension of the lingual underextension of the lingual vestibulevestibule

Omitting plunger lubrication Omitting plunger lubrication may make it difficult to may make it difficult to express the alginateexpress the alginate

Trapping tongue under the Trapping tongue under the tray will result in tray will result in underextension of the lingual underextension of the lingual vestibulevestibule

Problems with Syringe Problems with Syringe TechniqueTechniqueProblems with Syringe Problems with Syringe TechniqueTechnique

Severe gaggers poor tolerance Severe gaggers poor tolerance for intraoral motionfor intraoral motion

Use traditional techniqueUse traditional technique

Severe gaggers poor tolerance Severe gaggers poor tolerance for intraoral motionfor intraoral motion

Use traditional techniqueUse traditional technique

Diagnostic CastsDiagnostic Casts

Pouring a ModelPouring a ModelPouring a ModelPouring a Model

Weighing powder, Weighing powder, measure watermeasure water

Vacuum mix (less time, Vacuum mix (less time, stronger cast)stronger cast)

Use a two pour Use a two pour techniquetechnique

Weighing powder, Weighing powder, measure watermeasure water

Vacuum mix (less time, Vacuum mix (less time, stronger cast)stronger cast)

Use a two pour Use a two pour techniquetechnique

Two Pour TechniqueTwo Pour TechniqueIn Removable Prosthodontics: In Removable Prosthodontics: Preliminary Impressions OnlyPreliminary Impressions Only

Two Pour TechniqueTwo Pour TechniqueIn Removable Prosthodontics: In Removable Prosthodontics: Preliminary Impressions OnlyPreliminary Impressions Only

Pouring a ModelPouring a ModelPouring a ModelPouring a Model

Modulate speed of pouring by Modulate speed of pouring by tiltingtilting back and forth or back and forth or pressingpressing the tray more firmly onto the tray more firmly onto vibratorvibrator

Modulate speed of pouring by Modulate speed of pouring by tiltingtilting back and forth or back and forth or pressingpressing the tray more firmly onto the tray more firmly onto vibratorvibrator

Pouring a ModelPouring a ModelPouring a ModelPouring a Model

Model moist during trimmingModel moist during trimming Soak in slurry water, or soak Soak in slurry water, or soak

with base of cast in waterwith base of cast in water

Model moist during trimmingModel moist during trimming Soak in slurry water, or soak Soak in slurry water, or soak

with base of cast in waterwith base of cast in water

Pouring a ModelPouring a ModelPouring a ModelPouring a Model

Casts should be a minimum of 12 Casts should be a minimum of 12 mm (.5 inch) in thinnest partmm (.5 inch) in thinnest part

Separate the alginate impression Separate the alginate impression from the stone cast after 45 from the stone cast after 45 minutesminutes

Casts should be a minimum of 12 Casts should be a minimum of 12 mm (.5 inch) in thinnest partmm (.5 inch) in thinnest part

Separate the alginate impression Separate the alginate impression from the stone cast after 45 from the stone cast after 45 minutesminutes

Trimming CastsTrimming CastsTrimming CastsTrimming Casts

Trim the base on the Trim the base on the model trimmer parallel model trimmer parallel to the residual ridgesto the residual ridges

Leave the vestibular Leave the vestibular reflection intact for reflection intact for making a custom traymaking a custom tray

Trim the base on the Trim the base on the model trimmer parallel model trimmer parallel to the residual ridgesto the residual ridges

Leave the vestibular Leave the vestibular reflection intact for reflection intact for making a custom traymaking a custom tray

Trimming CastsTrimming CastsTrimming CastsTrimming Casts

All anatomical surfaces All anatomical surfaces should be included with should be included with minimum voidsminimum voids

All anatomical surfaces All anatomical surfaces should be included with should be included with minimum voidsminimum voids