Tissue Conditioner and Resin Base and Relines Flashcards
what is the powdered polymer for tissue conditioner made of
polyethyl methacrylate or isobutyl methacrylate
what is the liquid in tissue conditioner made of
an ester (butyl phthalate or butyl glycolate) in an alcohol solvent
what are tissue conditioners used for
lining the intaglio surface of a denture with a tissue conditioner improves retenetion and stability and relieves pressure
- allows abused tissues to recover
how are tissue conditioners used
polymer and monomer are mixed to make a gel then placed in denture -> insert for 5 minutes
describe tissue conditioners
- self curing and slowly polymerizing
- versatile and easy to use
what do tissue conditioners treat
- chronic denture soreness
- traumatized oral mucosa
- remodeling ridges
the sponginess of the tissue conditioner material absorbs:
loads to the underlying residual ridge and allows the tissues to heal during function
when does loss of resiliency occur with tissue conditioners
as the plasticizer leaches out and resin becomes stiff
how often should tissue conditioner be renewed
once or twice per week
what happens when the tissue conditioner is not renewed
the resin becomes stiff and produces the same tissue abuse that it was placed to treat
what are the uses of tissue conditioners
- prevent or treat chronic denture soreness
- stabilize temporary record bases
- stabilize immediate dentures during healing
- final impressions material for functional impressions
what are resilient liners and what are they used for
- a group of elastomer polymers
- used in a denture when a protective resilient surface is needed on the intaglio surface: sensitive mucosa, postradiation mucositis, poor supporting tissue, xerostomia patients, hypersensitive mucosa, bruxers, knife edge ridge/atrophy
how are resilient liners used
heat processed to the denture base as a reline procedure
elastic deformation of the liner does what
allows the material to absorb energy/pressure of occlusion, decreasing pressure on mucosa
what are the materials that make up resilient liners
- silicone elastomers
- polyurethane elastomers
- vinyl- acrylic polymers
- rubber
how long do liners last
6 months - 5 years
what are the other uses of resilient liners
- ridge atrophy - mental foramina, sharp ridges
- surgery contraindicated (implants not possible or implant failure)
- bruxers
- restore congenital/acquired defects- can engage undercuts with resilient prosthesis
- xerostomia - irradiation, medications
- relief areas- median palatal raphe
- single mandibular denture
what is an indication for metal base dentures
repeated fractures of a conventional denture.sometimes seen when a single denture opposes natural dentition
what are the advantages of the metal base dentures
- stronger, less likely to fracture
- less porous
- more accurate
- less deformation of base during function
- better thermal conductivity
- better tissue tolerance
what is a disadvantage of metal base dentures
difficult to reline
what are the materials used for cast metal bases
- Ni- Cr or Co-Cr
- Gold (type IV)
- aluminum
what are the tissue changes that occur
- stresses of daily function
- changes in general health status
- hereditary factors
- defects in dentures -> produce changes in tissue form
a procedure is needed every ____ after initial insertion
4-7 years
why reline/rebase?
- fit of the denture base to the foundation is poor
- denture is not stable and/or is non retentive
- denture base is fractured, discolored or underextended
what is the purpose of a reline
to produce an intaglio surface which fits the mucosa accurately without affecting the occlusion or the OVD
what are the tissue changes in a reline
tissues depart from the original form of the denture base
what is relining
replacing the intaglio surface of the prosthesis
what is rebasing
replacing the entire denture base (intaglio and cameo surface)
are the occlusal relationships altered in relining or rebasing
no
when do you reline
denture is not retentive, not stable
what are the occlusal considerations for relining
- existing OVD should be acceptable
- occlusion acceptable at centric relation position -> error if present, is slight and is correctable
when do you reline
- existing OVD is acceptable
- appearance of teeth and base acceptable
- acceptable occlusion at CR
- phonetics acceptable
when do you not reline
- teeth grossly malpositioned/worn
- occlusal plane erros
- poor esthetics/phonetics
- OVD in error
what are the errors to avoid in relining
- increasing the OVD
- denture with impression material is not fully seated in place -> increases the OVD
- allowing denture to move forward during reline impressions step -> alters the occlusal relationships
- allowing maxillary denture to move forward during impression step
- occlusal relationship errors
what do you do when relining
- develop tissue stops at VDO
- remove flange undercuts
- remove 1-22mm of resin base
- functional impression with Lynal 1-2 hours
- use adhesive and create relief holes
- flask the impression
- place posterior palatal seal before processing
what is the static impression
- closed mouth technique
- patient occludes at OVD
- functional movements made with tongue
- removed moments later, not hours later
- polysulfide, PVS, polyether
how often are relines needed with children, young adults, acromegaly patients and why
often because ridges are increasing in size
