S O M E PAT H O LO G I C A L C O N S I D E RAT I O N S

MUCOSAL RESPONSE TO ORAL PROSTHESES

-Aaron Sarwal

WHAT IS ORAL PROSTHESES?

• “Oral Prostheses” also known as “Dental Prostheses” is a specialist area of medicine which is concerned with the recreation of the dentition when there are missing or badly damaged teeth.

• It is covered under the ‘Prosthodontics’ branch of Dentistry according to the ADA.

• Prosthodontics is the dental specialty pertaining to the diagnosis, rehabilitation and maintenance of the oral function, comfort, appearance and health of patients with missing or deficient teeth and/or oral and maxillofacial tissues.

Oral Prostheses

WHY AND HOW DOES ORAL PROSTHESES CAUSE MUCOSAL PATHOLOGIES?

“1

• Appliance put in oral cavity

2

• Appliance surrounded by mucous membrane

3

• Disrupts normal oral conditions or oral environment

4

• Initiates response (pathological condition)

…the treatment modalities

which deal with the

replacement of missing teeth

and contiguous structures with

a suitable prostheses can

be broadly classified as

removable and fixed…”

TYPES OF ORAL PROSTHESES

Removable Prostheses(Denture)

Fixed Prostheses

(Implant)

• Prostheses are designed to conserve the

remaining structures and maintain them.

• Prostheses act as

etiological factors either due to error

from operator, inadequate

maintenance or the properties of

the material itself.

WHAT MUCOSAL PATHOLOGIES DOES ORAL PROSTHESES CAUSE?

Mucosal Pathologies of Oral Prostheses

Due to Removable

Mucosal Lesions

Burning Mouth Syndrome

Allergic response

Fungal Infection

Trauma (metallic clasps)

Due to Fixed

Secondary Caries

Pulpal and Periodontal Inflammation

Allergic Reactions

Occlusion Related Disorders

Periimplantitis

DENTURE IN THE ORAL ENVIRONMENT

‘Placement of removable

prostheses in the oral cavity

produces profound

changes of the oral

environment that may have

an adverse effect on the

integrity of the oral tissues.’

Denture in the Oral Cavity

Mucosal reactions

Mechanical irritation

Accumulation of microbial plaque

Allergic reactions

Poor function

Negative effect on muscle function

Surface Irregularities

and Microporosities

Plaque formation

Local Irritation

Increased permeability to

allergens

Bacteria use PMMA as

Carbon source

Accumulate, form Bacterial plaque

INTERACTION OF PROSTHETIC MATERIAL WITH THE ORAL ENVIRONMENT AND ITS CONSEQUENCES

• There are two types of consequences of prosthetic material in the oral cavity:

1. Direct 2. Indirect

• These are results of interaction of prosthetic material with the oral mucosa, and are influenced by:

a. Surface Properties: Chemical stability, Adhesiveness, Texture, Microporosities, Hardness

b. Chemical properties: Corrosion, Toxic Reactions, Allergic Reactions

c. Physical properties: Mechanical irritation, Plaque accumulation

d. Changes of environmental conditions: Plaque Microbiology

DIRECT CONSEQUENCES OF WEARING DENTURESPATHOLOGICAL CONSIDERATIONS

DENTURE STOMATITIS

Denture Stomatitis

Types and Clinical PresentationsCandida – associated

if yeast is involved.

Type ILocalized simple inflammation

Type IIGeneralized diffuse erythema in part or

entire denture-covered area.

Type IIIGranular type involves central hard palate and the alveolar ridges. Seen in association

with type I or type II.

CausesCandida – associatedStrains of genus Candida, in

particular Candida Albicans , cause denture stomatitis.

Type I, II and III trauma induced, caused by microbial plaque accumulation (bacteria or

yeast) on denture surface.Candida associated denture stomatitis and angular chelitis Angular chelitis or glossitis due to infection

from denture covered mucosa to angles of the mouth or tongue.

FLABBY RIDGE

Clinical Presentations:

• Alveolar ridge mobile, extremely resilient.• anterior part of maxilla, when remaining anterior teeth in mandible.

Histology:

• Marked fibrosis and inflammation, and resorption of the underlying bone.

Causes:• Replacement of bone by fibrous tissue.• Excessive load of the residual ridge• Unstable occlusal conditions.

Problems and Suggested Solutions:

• Provides poor support of the dentures.• removed surgically to provide the stability required by dentures.• extreme cases, total removal not done, leads to elimination of vestibular sulcus. • Resilient ridges provide some support for retention.

DENTURE IRRITATION HYPERPLASIA

Histology

• Hyperplasia of mucosa • Lesions single/ numerous/ consist of

flaps of connective tissue.• Development of elongated rolls of

tissue in mucofacial folds.• Inflammation is variable, deeper

fissures severe with ulceration.

Clinical Presentation

s

• Cells resemble normal cells, great increase in number.Histology

• Main cause ill-fitting denture• Lesions result of chronic injury by thin,

over extended denture flanges.Causes

• Replacement or adjustment of the denture, produces some clinical improvement

• Post surgical excision of the tissue, replacement of denture, lesions are unlikely to reoccur.

Problems and

Suggested Solutions

TRAUMATIC ULCERS

Clinical Presentations:

• ‘Sore spots in one to three days after new dentures.• Ulcers small, painful, covered gray necrotic membrane, surrounded by

inflammatory halo with firm, elevated borders.

Histology:

• Patient adapts to the condition, may develop into denture irritation hyperplasia.

Causes:

• Result of overextended denture flanges or unbalanced occlusion.

Notes:

• Suppression of mucosal resistance to mechanical irritation is predisposing e.g., diabetes mellitus and vitamin deficiency.

• Normally, the sore spots heal in a few days.

ANGULAR CHEILITIS

Clinical Presentations:

• Multifactorial disease, seen in denture wearers, adults and children.• Feeling of dryness and burning sensation at the ends of the mouth• Skin at the commissure appears wrinkled and macerated, even

ulcerated, never bleeds, crust may form.• Lesions stop at the mucocutaneous junction.

Histology: • Majority are Candida associated.

Causes:

• A result overextended denture flanges or unbalanced occlusion.• In patients with loss of vertical dimension, deep folds of skin are

produced at the corners of the mouth. Saliva collects in this area, the skin becomes cracked, macerated.

Treatment:

• Variable due to varied etiology, any infection present is secondary for permanent cure, the primary cause must be corrected.

• The lesions rarely completely disappear, usually reoccur in minor form.

Notes:

• A clinical diagnosis should only be arrived at after other lesions like due to known trauma, syphilis etc. are ruled out.

• Often associated with many other factors like infection and vitamin deficiency( esp Vit B) and loss of vertical dimension

ORAL CANCER IN DENTURE WEARERS

An association between the chronic irritation of the oral mucosa by dentures and oral cancer has been claimed, however, no definite proof exists.

Reports have detailed the development of oral carcinomas in patients who wear ill-fitting dentures.

The opinion is still valid that if a sore spot does not heal for long, malignancy may be suspected.

Patients with such lesions should be immediately referred to a pathologist.

Prognosis is poor for oral cancers, especially the ones in the floor of the mouth.

BURNING MOUTH SYNDROME (BMS)

Clinical Presentations:

Moderate to severe burning in the mouth is the main symptom of BMS and can persist for months or years.

For many people, the burning sensation begins in late morning, builds to a peak by evening, and often subsides at night. Some

feel constant pain; for others, pain comes and goes.

Oral mucosa appears healthy clinically.

Other symptoms of BMS include:• Tingling or numbness on the tip of the tongue or in the mouth• Bitter or metallic changes in taste• Dry or sore mouth.

BURNING MOUTH SYNDROME (BMS)

Treatment:

• Adjusting/replacing irritating dentures• Treat existing disorders e.g. diabetes,

supplements for nutritional deficiencies• Switching medicine, if a drug is causing BMS• prescribing medications to

• Relieve dry mouth• Treat oral candidiasis• Help control pain from nerve damage• Relieve anxiety and depression.

Notes:

• Anxiety and depression result from chronic pain.

• May have more than one cause. • Mostly, the exact cause of symptoms

cannot be found.• Treatment tailored to ones individual needs.• If no cause can be found, aim is to try to

reduce the pain associated with burning mouth syndrome.

GAGGING AND RESIDUAL RIDGE REDUCTION

GAGGING:• Normal, healthy defense mechanism,

prevents foreign bodies from entering trachea

• Many stimuli cause gagging, such as irritation of the posterior part of the tongue, soft palate, even sights, tastes etc. can cause gagging

• Due to dentures, patient may gag initially but gets accustomed.

• Gaging may also be a symptom of disorders and diseases of the GIT, adenoids or catarrh in the upper respiratory passage.

RESIDUAL RIDGE REDUCTION• Studies have established a continuous

loss of the bone tissue after teeth extraction and the placement of complete dentures.

• The resorption rate varies by individual.• Some say that RRR is physiological

process that occurs because the use of the alveolar bone is lost after tooth extraction, however, RRR can proceed to the basal bone and hence is believed to be a pathological process and not a physiological one.

OVERDENTURE ABUTMENTS : CARIES AND PERIODONTAL DISEASE

The retention of selected teeth to serve as abutments under complete dentures is an excellent prosthodontic technique.

However, bacterial colonization beneath a close fitting denture is enhances and leads to caries, due to microbial plaque of Streptomyces and Actinomyces (predominantly).

If the plaque is left undisturbed, it initiates gingivitis in one to three days.

Patients with overdentures demonstrate up to 30% increase in caries within one year.

Preventive measures should be aimed at preventing the accumulation of plaque near the roots.

INDIRECT CONSEQUENCES OF WEARING DENTURES

PATHOLOGICAL CONSIDERATIONS

ATROPHY OF MASTICATORY MUSCLES AND MASTICATORY ABILITY AND PERFORMANCE

Masticatory ability:• it is an individual’s own assessment of his/her

masticatory functionMasticatory efficiency:

• it is the capacity to grind the food during mastication.

Wearing dentures does compromise masticatory performance greatly as compared to a natural set of teeth

Essential that masticatory function (in complete denture

wearers) be maintained through

out life.

Masticatory function depends on the

skeletal muscular force and the ability to co-ordinate oral

functional movements during

mastication.

Maximal bite forces decrease in older

patients.Greater atrophy occurs in complete

denture wearers especially women.Little evidence that

new dentures reduce this atrophy.

NUTRITIONAL DEFICIENCIES

• Aging is often associated with a significant decrease in energy needs as a consequence of decline in muscle mass and decreased physical activity.

• There is a 30% fall in the energy however, with the exception of carbs, the nutritional requirement doesn't decrease with age.

• As a result dietary intake of elder individuals often reveals evidence of deficiencies clearly related to dental/ prosthetic status.

• Severe nutritional deficiencies are rare in the healthy, even with impaired masticatory functions, it is only in hospitalized/ chronically ill patients that inability to chew and altered taste perception lead to negative dietary habits and nutritional status.

ALLERGIC REACTIONS: INTRAORAL CONTACT ALLERGY REACTIONS

Generalized gingivitis as a symptom of IOCA to othodontic metals

• Poorly understood , not very commonly

dealt with in specialized literature.

• No single or specific clinical picture of

IOCA, lichenoid reactions common.• Metals used in dental practice – e.g.

amalgams ,Ni base metal alloys- cause IOCA reactions, hypersensitivity consequence of increasingly widespread use.

• Common allergens: 2-HEMA (hydoxyethyl

methacrylate) and triethylene glycol dimethacrylate.

• Methacrylates have rarely cause oral lichenoid reactions.

• Dental amalgams are the most common cause of IOCA.

• No single or pathognomic IOCA lesion exists.

• Replacement of restorations containing materials that give a positive epicutaneous test is not warranted.

• Allergy due to many nonspecific or unclear intraoral clinical disorders.

PERIIMPLANTITIS

• Soft and hard tissues surrounding osseointegrated implant show similarities with periodontium.

• Big difference in the collagen fibers being non-attached and parallel to implant surface instead of being perpendicular and in functional arrangement from bone to cementum.

• Periodontitis like process- periimplantitis affects implants and leads to loss osseointegrated implant.

• Bacteria play significant role in this, similar to periodontitis, failing implants include gingival inflammation, deep pockets and bone loss.

• Bacterial flora is gram negative rods e.g. Bacteroides and Fusobacterium sps.

• Probing depths > 6mm and periimplant radiolucency.

PERIIMPLANTITIS

• Etiology is either infection with periodontal pathogens of increased trauma (retrograde periimplantitis).• Implants have less effective soft tissue

barrier around their necks than natural teeth, less resistant to infection.• The micro flora associated with failing

implants is similar to that of periodontally affected teeth.• Treatment involves determination of the

etiology, it’s control along with hygiene techniques, instrumentation and use of antimicrobials.

CONCLUSION

• ‘Placement of removable prostheses in the oral cavity produces profound changes of the oral environment that may have an adverse effect on the integrity of the oral tissues.’ (Mahesh Verma, Shafers’s)

• Mucosal reactions occur from the mechanical irritation, accumulation of microbial plaque and occasionally due to allergic reactions.

• Dentures that function poorly may act as negative factors in muscle function

• Surface irregularities and micro porosities can greatly encourage plaque formation.

• At times, the local irritation may end up increasing the permeability of the mucosa to allergens, hence making it difficult to distinguish between simple irritation and an allergic response.

• Some bacteria can use the PMMA as a carbon source and hence the accumulation of bacterial plaque at the interface of the denture and mucosa causes several negative effects.

RESOURCES

• Appendix II, Shafer’s Textbook of Oral Pathology.(“Mucosal Response To Oral Prostheses: Some Pathological considerations” - Dr. Mahesh Verma)

• Image credits:Internet (http://www.google.co.in/imghp?hl=en&tab=wi)

• General research on the web was also done in making this presentation just to confirm the information and update it where required.

• Burning Mouth Syndrome slide source: http://www.nidcr.nih.gov/OralHealth/Topics/Burning/BurningMouthSyndrome.htm

Special thanks to :Dr. Rupinder Kaur

(Ex-Lecturer, Department of Dental

Anatomy and Oral Pathology, Gian

Sagar Dental College and Hospital)

for much needed and very valuable feedback, that

helped to improve this PowerPoint

many-fold …

Thank You!