Prosthodontics: Pre-Prosthetic Surgery/Complete Denture Flashcards
Frenectomy
Complete removal of Freenum
High Freenum Attachment
* neart top of alveolar ridge
Most to least common:
Labial>Buccal>Lingual
Free Gingival Graft
widen band of keratinized tissue
* Below gingival margin
Requires revascularization from recipient bed
Graft=palate
*includes surface epithelium
* ideal thickness: 1-1.5 mm
Might Need for overdenture teeth
Hypermobile Ridge
Flabby edentulous ridges in anterior maxilla
Tx: tissue conditioner if inflamed
* electrosurgery or laser surgery if not effective, can also eliminate the vestibule
What treatment should be done if a hypermobile ridge is inflamed?
Tx=Tissue Conditioner
* Electrosurgery or laser surgery if not effective
What do you need to do if your taking an impression w/a hypermobile ridge?
Large relief in a tray
OR
perforate custom tray
to avoid displacing the ridge
Epulis Fissuratum
Hyperplastic tissue reaction
* due to ill fitting denture or overextended flange
Epulis Fissuratum Treatment
Tissue Conditioner & Adjust Flange
Fibrous Tuberosity
aka Pendulous Tuberosity
Large Tuberosities touch retromolar pads
* limits interarch space
Tx: Surgical excision
Papillary Hyperplasia
Multiple papillary projections on palate
* Etiology: Candidiasis
What causes Papillary Hyperplasia?
due to:
* local irritation
* ill-fitting denture
* poor oral hygiene
* leaving dentures in all the time
When can you leave retained root tips?
Can be left if:
* intact lamina dura
* no radiolucency
What is the etiology of Papillary Hyperplasia?
Candidiasis
Papillary Hyperplasia: Treatment
Tx: OHI, leave dentures out at night, soak in 1% bleach and rinse thoroughly
Combination Therapy:
* General
* Signs/Symptoms
Only have mandibular anterior teeth
* bone resorption in maxillary anterior
Signs/Symptoms:
* overgrowth of tuberosities (Fibrous tuberosities)
* Papillary hyperplasia in hard palate
* Extrusion of lower anterior teeth
* Bone loss under partial denture bases
Retained Root Tips
Residual RT (Non-RCT)-infection risk
Can be left if:
* intact lamina dura
* no radiolucency
Paget’s Disease
Etiology: Unknown
Dentures not fitting
* need to remake periodically
Alveoplasty
Surgical reshaping of alveolar bone
* sharp, spiny, or irregular ridges
Tori removal indications
Creates an undercut (lingual torus)
interferes w/posterior palatal seal (palatal torus)
Bone Augmentation
Horizontal>Vertical
* easier to restore horizontal ridge width vs height
VDR
Vertical Dimension of Rest
Distance b/w nose and chin at rest
* elevator and depresssor musccles are in equilibrium (PRP=Physiological rest position)
3mm of space b/w upper and lower premolars
VDO
Vertical Dimension of Occlusion
Distance b/w nose and chin when biting together
* =superior-inferior relationship b/w maxilla and mandible in MI
Interocclusal Space
VDR=VDO+ 3mm
the difference b/w VDR and VDO
* ideally 2-4 mm
Excessive VDO
- Fatigue of Muscles of Mastication
- Lips appear strained
- Gagging
Insufficient VDO
**Aged appearance-lower 1/3 of face
Angular Cheilitis
Christensen’s Phenomenon
Distal space b/w maxillary and mandibular occlusal surfaces when mandible is protruded
* posterior open bite
Camper’s Line
imaginary line from ala of nose to tragus of ear
Interpupillary Oline
imaginary line b/w pupils of eyes
Complete Denture: Plane of Occlusion
Maxillary wax rim parallel to:
* Camper’s line
* Interpupillary line
Complete Dentures: Balanced Occlusion
Simultaneous anterior and bilateral posterior contnacts in centric and eccentric movements
* aka Tripodization
* avoid anterior guidance to prevent dislodgement
On balancing side
* maxillary lingual cusps –>lingual incline of mandibular buccal cusps
On working side:
* maxillary lingual cusps –> facial incline of mandibular lingual cusps
* Mandibular Buccal cusps contact lingual incline of maxillary B Cusps
Complete Denture: Lingualized Occlusion
Only maxillary posterior lingual cusps contact mandibujlar posterior teeth
* prevent dislodgement
Bennet Concepts: Bennett Angle vs Shit vs Movement
Bennett Angle:
* nonworking side condyle angle: From anteriorly and medial to sagittal plane
* 15 degrees
Bennett Shift:
* Lateral movement of mandible towards working side during lateral excursions
Bennet Movement:
* lateral movement of both condyles towards working side
* TMJ Looseness
Factors that Favor Disclusion(seperation) of posterior teeth (NO ECCENTRIC CONTACTS)
*Anterior Guidance
*Posterior Guidance
* Cusp Anatomy
* Tooth arrangement
*Occlusal plane orientation
Horizontal=protrussive
Lateral=excursive
Curve of Spee
AP Curve
* load on long axis of each tooth
More mesial tilted as you move distal
Curve of Wilson
Mediolateral Curve– along posterior cusp tips
* Load on long axis of each tooth
More lingual tilt as you move distally
Support
Resistance to Vertical Seating Forces
Support for Upper and Lower arch and form the Denture POV
Upper:
* Palate
* Alveolar Ridge
Lower:
* Buccal Shelf (mainly)
* Retromolar Pad
Denture:
* Denture Base
Stability
Resistance to horizontal dislodging forces
Stability for Upper and Lower arch and form the Denture POV
Upper/Lower:
* Ridge Height
* Depth of Vestibule
Denture:
* Denture Flange
Retention
Resistance to vertical dislodging forces
Retention for Upper and Lower arch and form the Denture POV
Peripheral Seal
Adhesion
Attraction of Unlike Molecules
saliva to tissues, saliva to denture base
* best seal created by intimate contact of denture base to tissues
Occlusal Prematurities break retention
Cohesion
Clinging of Like Molecules
* Saliva to Saliva
Unfavorable: Thick ropy saliva
Favorable: Thin and water saliva=better retention
Surface Tension
Combo of adhesion and cohesion forces
* maintain film integrity
Water molecules are more attracted to each other than surrounding air
Overextension
Denture Flange is too long
* get sore spot or ulcer after wearing for a while
* Tx: Relieve denture and re-eval in a few weeks
* trim the denture basck where it impinges on tissue
Denture extends too far back (Posterior)
* denture teeth are set so far back-go up onto ramus
* occlusal forces dislodge denture
Underextension
Denture Flange is too short
* No retention
What is the best indicator for success of a denture?
Ridge
* provides all 3: stability, suppport, retention
* Wide braod ridge=Best
Heat Cured Acrylic
PInk Acrylic on Dentures
2 components:
* PMMA=polymer (powder)
* MMA=monomer (liquid)
Liquid component of Heat-Cured Acrylic contains
Methyl Methacrylate (MMA): Monomer
Hydroquinone: Inhibitor
* prevents polymerization of MMA
Glycol dimethacrylate: cross-linking agent
* Increases Rigidity
Dimethyl-p-toluidine: Activator
Powder Component of Heat-cured Acrylic contains:
Polymethyl Methacrylate (PMMA): powder
Benzoyl Peroxide: Initiator
Iron and Cadmium salts or organic dye: Pigment
Denture Processing: Problems
Always shrink
* more shrinkage if excess monomer
* Ideal monomer to polymer ratio: 1:3
Porosity
* due to underpacking with resin at processing or heated to quickly
What are the 2 materials used to make denture teeth?
Acrylic
Porcelain
Acrylic vs Porcelain Denture Teeth
Acrylic:
* Better retention: bond to acrylic resin of denture base (Better Bonding)
Porcelain:
more esthetic
* more stain and wear resistant
Brittle
wear opposing teeth
Mechanical retention
* Anteriors=Pins
* Posteriors=diatorics
