post insertion problems: relines, rebases, and repairs

lecture given 9/8/2026

how often should an average denture be replaced?

6-10 yrs

resorption

remodeling that results in a net loss in dimensionl quality, and quantity of the edentulous ridge

what does resorption depend on?

age

sex of the pt

time passed since tooth extraction

pts health

amount of physical trauma of the gingiva

what questions should you ask to evaluate the existing denture?

are the denture bases stable?

are the prosthetic teeth excessively worn?

is there appropriate anterior tooth display?

can pt bite and eat well?

are there any fractures or cracks in the denture base?

are there any broken or missing prosthetic teeth?

what are the most common complaints about a denture?

discomfort, speech, gagging, retention

how can you eliminate a denture problem?

correctly identify the cause

what are possible causes of sore spots?

excessive pressure areas

roughness or sharp areas

overextensions- borders too long or too wide

errors in occlusion causing movement of the denture

insufficient relief over undercuts

unresolved or previously existing sores or pathology

what are possible causes of gagging?

posterior border of maxillary denture too long or too thick

disto-lingual flange of mandibular denture too long or too thick

maxillary occlusal plane too low

mandibular teeth set too far lingual triggering tongue gagging

excessive increase in the VDO

what are possible causes of sore throat?

overextension and ulceration on soft palate

overextension beyond hamular notch, distobuccal of maxillary denture, distolingual of mandibular denture

pressure indicating paste

accurate means of detecting pressure points

what are the steps for PIP or fit checker?

dry denture

use disposable brush or new tip and apply in a thin layer (but not too thin)

seat denture in pts mouth w light pressure

slowly apply pressure or ask pt to close

evaluate flange extensions, stabilize the denture, and manipulate the cheeks or lips

what do each of the letters show?

N- no contact

C- contact, good

I- too much contact

what are possible causes of whistling during ‘S’ sounds?

maxillary anterior teeth set too far labial

insuffient base material on lingual of maxillary anterior teeth

posterior teeth set too far lingual

posterior denture base too thick

what are possible causes of ‘S’ sounds sounding like ‘SH’?

maxillary anterior teeth set too far lingual

excessive base material in lingual of maxillary anterior teeth

posterior denture base is too thin, air escapes from lateral borders

what are possible causes of ‘F’ sounds sounding like ‘TH’?

poor maxillary anterior teeth set up (too buccal or too palatal)

what are some possible ways to handle/fix speech problems?

sometimes trim and reshape teeth

remake

what are possible causes of cheek biting?

insuffient horizontal overlap of posterior teeth (most common)

lack of clearance between denture bases distal to last tooth

sharp buccal cusps

posterior teeth too large or extend too far posteriorly

incorrect VDO

what are possible causes of dentures loosening while eating?

maxillary teeth are set too far buccal to crest of ridge

mandibular occlusal plane higher than retromolar pads

mandibular teeth are not on the center of the ridge

occlusal interferences

no balanced occlusion

what is clinical remount needed for?

balance occlusion

what is the purpose of facebow preservation?

preserves relationship of upper arch to condyles

how can you prevent facebow preservation from locking in when it is being created?

minimal indentation

what do you have to do if you don’t have a facebow preservation during the delivery appointment?

re-do the facebow!

in what order should you callibrate occlusion?

centric relation

lateral

protrusive

recheck centric

with 33 degree/0 degree teeth, how should the teeth contact in centric occlusion?

maxillary lingual cusp rests on central groove of mandibular teeth

when adjusting dentures in central occlusion, what should you NOT touch?

upper lingual cusp tips

what are signs of excessive VDO?

strained lips/lip incompetence

muscular discomfort

premature contact of posterior teeth when speaking (clicking)

difficulty pronouncing some words

sore throat

what are some signs of insufficient VDO?

mout commissures downturder (with possible angular chelitis)

diminished dimension in the lower 1/3 of the face

aged appearance

muscular discomfort

what are possible causes of loose maxillary dentures?

lack or incorrect posterior palatal seal

inadequate clearance for buccal and labial frenum

short on hamular notches

dry mouth

inaccurate denture base

posterior border too short or thin

short labial flange

execessive space for frenum notch

what are possible causes of maxillary denture dropping on opening?

posterior borders too long or too thick

flanges overextended

inferference with coronoid process

inadequate clearance for frenums

what are possible causes of maxillary dentures loosen when speaking?

inadequate posterior palatal seal

inferference with coronoid process of mandible

posterior border too long or thick

short labial flange

excessive space for frenum notch

what are possible causes of loose mandibular dentures?

poor ridges for support

over-extension of base

under-extension of base

thickness in lingual border in molar area

retracted tongue position

posterior teeth set too lingual

dry mouth

how can you handle retention issues in an interium denture?

soft reline?

how can you handle retention issues in a complete denture?

hard reline- chairside or lab

rebase

relines

indicated when intaglio of denture no longer fits the supporting mucosa

benefits- can be done the same day as the impression or within 24 hrs

risks- compromised adhesion of new acrylic to old acrylic, presence of uncured residual monomer and porosity

can be chairside (direct method) or in lab (indirect)

tissue conditioner

primarily used for tissue conditioning after extractions, during healing, or for poorly fitting dentures where tissue health needs improvement

short term- typically lasts a few days to a few weeks

soft reline

used to provide long-term in cushioning and support for the denture, improving comfort, and stability

last longer, typically 3-6 mo

hard reline

performed to improve the fit of the denture where it is in contact with the supporting gums

considered a permanent solution to ill-fitting dentures

involves resurfacing of the denture on the intaglio with a new layer of denture base material

can be chairside (direct method, in 1 appt), or at dental lab (indirect method, in 2 appts)

direct hard reline

accomplished by making an intraoral, closed- mouth impression techinique within the denture using a chairside lining material that bonds to the inner surface of the denture

closed mouth impression technique

a method to take an impression with the pt closing the mouth and relying only on their movement

the function is to obtain optimal muscle trimming and impression with pts functional pressure and movement

what are contraindications for direct hard relines?

there is a risk of allergic reaction to uncured methacrylate monomer

autopolymerizing may cause chemical burns

porosity may occur in the absence of hydraulic pressure, which contributes to foul odors

incompletely cured acrylic is not color stable

controlled positioning is difficult to achieve and is very difficult to correct if errors

indirect hard reline method

performed in the lab with special curing equipment

includes the generation of an impression, stone cast, and then applying new denture base material to the internal aspect of the denture

pt will not have their denture for ~a week!

repairs for broken dentures

can be really simple or extremely complex

cracks- midline may be relatively simple, but if the crack does not reapproximate because of splintering of the base, repair is more complex

denture tooth becomes debonded or chipped

technique sensitive- cna be in dental lab or by a trained dentist in a dental office

what are the steps of fixing a fractured denture?

reapproximate the fracture and stabilize it- cyanoacrylate glue, sticky wax

verify stability, fit, and occlusion

putty matrix made to record intaglio

fracture is separated or tooth fragment removed, fracture should be widened with bur at least 2mm for optimal thickness of PMMA, undercuts and bevels placed, wire can be placed along lingual portion for improved strength

condition prepared acrylic surfaces and apply denture acrylic into fracture using salt and pepper technique

cure repair material according to manufacturer instructions, finish, and polish

how can you replace a fractured tooth?

select replacement tooth

remove tooth that will be replaced

try in selected tooth

create bevel on lingual

position replacement tooth with wax and secure it with sticky wax

create an index

position tooth

place index into labial surface and secure it in place

salt and pepper

fill labial interface

finish and polish

how should you deliver a fixed denture?

inspect them for defects, voids, or irregularities

deliver them in the same manner as a new denture

evaluate occlusion

rebase

original base material is removed from denture and a new wax up is made with original teeth

wax is processed into fresh PMMA

when are rebases indicated?

when intaglio has lots its fit due to changes in the residual alveolar bone and the loss of fit is so great that a regular reline would result in a base that is too thick

what are the benefits of a rebase?

new base processed in the same manner as an existing denture

what are the risks of rebase?

fracture or aberrant repositioning of existing teeth during processing

additional processing time

higher lab fees

what are indications for rebase?

if the observed clinical changes are moderate to minimal

when denture base has to be changed due to processing defects

denture teeth should be in good condition

tldr reline

replace tissue contacting surface only

option of doing it chairside or in lab

tldr rebase

replace entire base

can only be done in lab

rarely done, remake is usually better