Effects of dental appliances
on oral health
Unit 8 Dental Public Health
and Preventative Dentistry
Do We Need to Replace all
The opinion of the patient and the dental
team regarding the nature of dental
treatment required can often differ. A
greater disparity is apparent the older the
patient, so many factors have to be
considered during treatment planning.
It is not always necessary to replace all
missing teeth any decision to do so
must be made with the goal of improving
function, appearance and comfort.
Consider the following
• Does the patient have any problems
• Does the patient have any discomfort
arising from the missing teeth?
• Does the patient have any appearance or
cosmetic concerns arising from missing
• Is there any evidence of occlusal
Does the potential benefit of providing a
prosthesis outweigh the potential damage it
may cause to the remainder of the natural
Removable partial dentures in
particular are associated with high levels of
dental caries and periodontal disease,
particularly in patients who are unable to
maintain adequate oral hygiene.
Protect the patient!
One of the standards for DCPs as required
by the GDC.
Adults in particular have the capability to
adapt to the gradual loss of teeth and
patients who have adapted well are unlikely
to seek treatment unless anterior teeth are
Ill fitting dentures can contribute to the
decline of tissue health in the oral cavity.
This can be due to:
• An inaccurate impression or distortion
• A breakdown in communication within the
dental team and between the patient!
Epulis fissuratum where the
partial denture rests
Hyper plastic folds of an epulis
Fissuratum caused by irritation of a
What is Pathology?
Pathology is a varied field of science, one of
the oldest disciplines, which focuses on
the study of diseases.
It should be noted that a number of
conditions increase in prevalence with age.
Threatening oral health!
Tooth Supported dentures
Encroaching upon the gingival tissues with
components of the denture such as
Connectors and clasp tips, is a common fault
in the design of tooth supported dentures
Tooth damage & decay caused by a
poorly designed dental prosthesis
This is particularly common in the
prescription of removable partial dentures
Threats of disease, can be
minimized, however, by following a few basic
Provide tooth support for the denture where
possible – wrought rests can be incorporated into
acrylic RPDs to provide tooth support.
Chrome based dentures should have rests placed
on the tooth surfaces adjacent to the saddles.
Regular inspection of the denture fit is
necessary to ensure it is not causing
damage – at least once a year!
Incorporating occllusal rests in partial
dentures may prevent vertical
Keep the RPD design as simple as possible,
Minimising coverage of the dental and
Connectors should not encroach on the
Gingival margins of the teeth, and clasps
should not cover exposed root surfaces
Tooth damage caused by vertical
movement of denture
As technicians involved in the design
process, we can utilize technology further to
eliminate future problems developing.
In the case of RPD design, tooth stops and
occlusal rests will act to prevent soft tissue
Denture wearers need to avoid plaque buildUp that can irritate tissues under the
Ill fitting dentures can increase the possibility
of oral cancer and denture wearers should
see a dentist once a year for screening.
• Reduced saliva flow
• Increased sensitivity in changing and
tissue that becomes increasingly thin
• Dentures that do not dimensionally change
in accordance with the changing shape of
• Are all factors that need to be considered
in order to improve oral health.
Instruct the patient in cleaning techniques for
both the RPD and natural teeth.
This will include careful instruction in oralhygiene procedures, and encouraging the
patient to clean the denture after meals and
to use denture cleaners
Dentures need to be checked for proper fit to
Avoid irritation, increased bone loss and
A change in the fit of a RPD could indicate
A condition of unknown cause but associated
with the presence of dentures, characterized
by numerous red papilary projections on the
Dentures can harbour numerous pathogenic
and opportunistic bacteria .
A spectrum of microorganisms can be
found harboring in dentures.
These organisms can instantly adhere to the
denture surface and penetrate the pores left
during the release of gases from
As at technician it is important to use a good
quality material and ensure processing and
finishing is of the highest standard in order to
eliminate these problems and prevent further
Denture surfaces should be
smooth and well polished!
Similarly, care has to be taken with
the production of ceramic restorations microporosity can also harbour bacteria and microorganisms.
Fortunately as technicians, we can reduce
the likelihood of this occurrence by ensuring
a nice smooth finish to the material with no
processing faults – cracks/porosity and /or
using a glazing product
Rampant decay under
old improperly bonded
Avoidable!... with the application of
correct preparation and appliance
Once again it is the breakdown in
communication within the dental team that
had led to a failure in this restoration
resulting from poor margin design with blame
being attributed to both the surgeon and
Effect on Bacteria on Oral
What are virulence factors?
Virulence factors assist bacteria in achieving
success to and colonising sites i.e. molecules
produced by a pathogen that specifically
Bacteria adheres to the acquired pellicle,
(a cellular film composed of glycoprotein that
closely and firmly adheres to tissues of the
This bacteria can accumulate to the extent
That it is able to withstand the
Mechanical cleansing effects of the soft
oral tissues and salivary flow.
Certain species of bacteria have the ability to
invade soft tissues i.e. gingivae, delivering
toxic bacterial products to the tissues
A bacteria that causes gum disease
and has been linked to heart disease.
Components of poorly designed restorations
or appliances can cause direct local irritation
and trauma to the gingivae
Over contoured restorations may
have serious health implications
Poorly contoured fixed restorations may be
More problematic rather than being a solution
Poor oral hygiene – accumulated food debris
from packing beneath open contact points in
furcations, beneath overhanging or leaking
restorations and associated dentures.
Factors that predispose to the accumulation
of plaque, include poorly designed
restorations with overhanging margins,
poorly contoured and deficient restorations
Patients suffering from
As part of a patients periodontal treatment,
it may be necessary to allow access for
cleaning. Long – term wear of properly
fitting and contoured provisional
restorations allows the health of the
gingival margin to improve and it’s position
to stabilize before impressions are taken
for definitive restorations.
Overhanging margins and ill fitting furcations
(division of the tooth root) can also lead to