PHYSICAL & CHEMICAL INJURIES OF ORAL CAVITY

CONTENTS

• INTRODUCTION

• INJURY

• INJURIES OF TEETH ASSOCIATED WITH TOOTH PREPARATION

• EFFECT OF HEAT

• EFFECT OF RESTORATIVE MATERIALS

• PHYSICAL INJURIES OF TEETH

• PHYSICAL INJURIES OF BONE

• EFFECT OF ORTHODONTIC TOOTH MOVEMENT

• PHYSICAL INJURIES OF SOFT TISSUES

• RADIATION INJURIES

• CHEMICAL INJURIES OF ORAL CAVITY

• OCCUPATIONAL INJURIES OF THE ORAL CAVITY

• OCCLUSAL TRAUMA

• CONCLUSION

• REFERENCES

INTRODUCTION

• Oral lesions associated with trauma are a relatively common finding in dental

practice. A diverse array of oral mucosal disorders caused by acute and chronic

trauma exists.

• They manifest in the oral mucosa as acute or chronic ulcers, white or red lesions,

mucositis, and reactive hyperplasia or even as bone exposures with

sequestration.

• Such lesions may also impair oral functions to a significant extent and also pose

some difficulties in arriving at a diagnosis especially the chronic lesions.

• Similarly chemical injury could result from undue or careless handling of chemicals and dental instruments during dental treatment procedures.

• A wide array of chemicals and drugs come into contact with oral mucosa and some of them may cause direct mucosal trauma due to their caustic nature.

• Some people tend to apply certain chemicals as a remedy for their oral problems such as application of aspirin to ease toothache.

• Health care practitioners are also responsible in applying certain chemicals in the mouth for treatment or investigative procedures.

Chemical burns

INJURY

• It is defined as harm or hurt; usually applied to damage inflicted on the body by an external force, called as trauma or wound

Injuries of the Teeth Associated with Restorative Procedures

Effect of Tooth Preparation:

• The effect of preparation of teeth on dentin and pulp alone is difficult to asses

except in sound teeth since the carious lesion itself produces demonstrable

changes in both these structures.

• Rotary instruments with stainless steel burs, tungsten carbide and diamond burs

of different sizes and shapes are routinely employed to prepare cavities and

crowns.

Reactions to Rotary Instrument• Hence preparation of tooth without adequate cooling or excessive drying of the

dentin after cavity preparation results in excessive heat and evaporation of

tubular contents.

• This leads to displacement of odontoblast nuclei into the dentinal tubules and a

marked disorganization in the organelles of the odontoblasts and in the adjacent

cells, which might include intracellular disorganization, rupture of the nuclear

membrane and lysis of cellular elements.

• Effect of air abrasive techniques:

•Aluminum oxide under high pressure is use. It does not allow the stereognostic

ability of the controller. Working time is the most important to determine the

depth of preparation.

• Effect of Ultrasonic Technique:

• It has been advocated as it involves less heat, noise and vibration in contrast to

rotary instruments.

•Studies have shown that there is no remarkable differences in the reaction of

dental pulp to steel burs, diamond burs or ultrasonics.

• Lasers

•Carbon and Nd:YAG are most commonly used.

•On tooth it produces a glass like fusion of the enamel and definitive charred

crater on dentin.

•On pulp it shows severe pathologic changes including hemorrhagic changes

with acute & chronic inflammatory cell infiltrations.

Effect of Heat

• Thermal changes are influenced by

1. The size, shape & composition of bur or stone

2. The speed of bur or stone

3. The amount & direction of pressure applied.

4. The amount of moisture in the field of operation.

5. The length of time that the bur or stone is in contact with the tooth

6. The type of tissue being cut, enamel or dentin

SMEAR LAYER The cut surface of enamel and dentin, when examined after preparation with

hand instruments or burs reveals the presence of covering layer of cutting debris from mineralized tissues referred as the “smear layer” which is less than 2μ.

Effect of Restorative Materials

• Remaining Dentin Thickness(RDT):– It is the most important deciding factor before placing the restorative materials.–2μ or more is sufficient for proper insulation by the dentin itself.– If its less than 2μ additional agents such as cements or bases are required before

placing the restoration.

Zinc Oxide & Eugenol:

• Eugenol of the cement fixes cells, depresses the cell respiration and reduces the neural transmission in vitro.

• It is considered as the least injurious of all filling materials to the dental pulp.

Zinc Phosphate cement:

• Majority of investigators have reported significant deleterious effects on the pulp when the material is placed, the actual injurious agent is supposedly being the phosphoric acid.

Silver Amalgam:

• It is used as filling material which is generally innocuous material, particularly in shallow cavities.

• However Manley found that there is decrease in odontoblasts number with mild inflammation of pulp.

• New studies have found that the pulp response is due to the leakage around the restoration rather than the material by itself. There is slight inflammation of gingiva when contacted due to the corrosive products & plaque.

Glass Ionomer:

• Its is considered as biocompatible and is widely used as filling, lining and luting agent.

• It has the advantage of chemically bonding to the mineralized tissue and release of fluorides.

• Pulpal pain may be present for a short period after the filling material due to the increased dentin permeability after acid etching.

• Self Polymerizing Acrylic Resin:

• Extensively used as restorative materials, particularly in anterior teeth.

• Results indicated that these resins provoked odontoblastic damage and pulpal inflammation which is more severe in deeper restorations.

• Pulpal reaction is mainly due to the shrinkage causing leakage.

Conventional Composite Resins:

• These showed the same irritational characteristics of unfilled resins.

• Hence pulpal protection is required in such cases to prevent damage and calcium hydroxide base is a preferred.

Microfilled Composite Resins:

• It is comparable to those of conventional composite resins hence pulp protection

is required under deep cavities.

Acid Etching:

• Most commonly employed chemical is phosphoric acid.

• This considerably demineralize the dentin exposing collagen. It forms an

interwoven mesh of fibers in which resin is infiltrated forming a “hybrid layer.”

Effect of Cement Bases, Cavity Liners, Varnishes and Primers

• These are generally used for one or more of the following purposes:

1. To serve as bacteriostatic agent.

2. To provide thermal insulation, particularly under metallic restorations.

3. To provide electrical insulation under metallic restorations.

4. To prevent the discoloration of tooth structure adjacent to certain type of

restorative materials.

5. To prevent the deleterious constituents of restorative materials into dentin and

pulp; and

6. To improve the marginal seal of certain restorative materials by preventing

microleakage and the ingress of saliva and debris along the tooth-restoration

interface.

PHYSICAL INJURIES OF TEETH• Bruxism

–It is the habitual grinding or clenching of the teeth , either during sleep or as an unconscious habit during waking hours.

–Includes both clenching habit & also to the repeated tapping of the teeth.

– Bruxism is one of the most common sleep disorder.

–According to Nalder and Meklas it described as

i. Local

ii. Systemic

iii. Psychological and

iv. occupational

Why?

• Local Factors : associated with some form of mild occlusal disturbances which produces mild discomfort and chronic, even though unrecognized, tension.

• Systemic Factors: it includes gastro-intestinal disturbances, subclinical nutritional deficiencies etc.

• Psychological Factors: it is the most common cause for bruxism. High levels of

anxiety, stress and emotional tension may be expressed through a number of

nervous habits, one of which may be bruxism.

• Occupational: certain occupations lead to this habit. Athletes engaged in

physical activities and in occupations in which the work is unusually

precise, such as that of watchmaker it is seen.

• Clinical Features:–According to Glaros and Rao

a. Effects on dentitionb. Effects on periodontiumc. Effects on masticatory musclesd. Effects on temporomandibular jointe. Head pain andf. Psychological and behavioral effects.

• Treatment & Prognosis:–Underlying cause must be cured first.–Removable splints which are worn at night to immobilize the jaws or guide the

movement so that periodontal damage may be minimal.–Botulinum toxin (Botax) is used now a days injected in masseter muscle without

effecting chewing or facial expressions.– If left untreated, severe periodontal and/or temporomandibular disturbances may

result.

• Fractures of Teeth:

–Commonest injury which may arise in variety of situations, the most frequent of which is sudden severe trauma such as fall, blow, an automobile accident or any of a large number of incidents in which children especially are frequently involved.

–It mostly involves boys and anterior maxillary teeth.

–Most followed classification is Ellis & Davis.

•Class 1- simple #(Fracture) of crown, involving little or no dentin.

•Class 2- extensive # of the crown, involving dentin but not dental pulp.

•Class 3- involvement of pulp in addition to class 2

•Class 4- the traumatized tooth becomes non vital with or without loss of crown structure

•Class 5- teeth lost as a result of trauma

• Class 6- # of root with or without loss of crown structure.

• Class 7- displacement of a tooth

without # of crown or root.

• Class 8- # of crown en masse and its

replacement

• Class 9- traumatic injuries to

deciduous tooth.

• The treatment is based on whether

there is exposure of pulp or not and

the time elapsed after the trauma.

• Root Fractures:

–These are uncommon in young children as their socket is not much developed with resilience.

–Mostly seen in between ages 10-20.

–Depending on site of fracture there may be loss of crown or mobility of crown structure.

–In some cases there is formation of dentin barrier and cementum resulting in healing of the fracture.

• Abrasion:

–Wearing away of tooth substance due to mechanical means is known as

abrasion.

–Commonly seen in habits like holding pins, opening bottles with teeth etc., in

some occupations such as tailoring, carpentering etc.

• Injuries to the supporting structures of tooth:

–Concussion:

• it is produced by injury which is not strong enough to cause serious, visible

damage to the tooth and the periodontal structures.

•Characterized by increased sensitivity of tooth to percussion in any direction.

•Treatment include selective

grinding of teeth to remove

occlusal contacts.

–Subluxation:

•Refers to abnormal loosening of tooth without displacement due to sudden

trauma.

•Tooth is mobile on palpation and sensitive to percussion and occlusal forces

with gingival bleeding in the crevice.

• In time it becomes non-vital due to severance of apical blood supply.

–Avulsion:

•Dislocation of the tooth from its socket due to traumatic injury. It can be partial or total.

•Partial avulsion includes intrusion, extrusion, or facial, lingual, or palatal, or lateral displacement.

• It is usually associated with fracture of socket.

• Partial can be treated by repositioning and splinting of teeth. Complete avulsion can be treated by re-implantation.

• It success is dependent on time elapsed from injury to the placement and medium in which it is carried.

• Tooth Ankylosis:

–Fusion between bone and tooth, termed ankyloses is an un common phenomenon in deciduous dentition and even more rare in permanent dentition.

–Ankylosis ensues when partial resorption of tooth has occurred and replaced with bone or cementum uniting the tooth with bone during repair.

–Usually becomes apparent during tooth

removal, which considerable difficulty will

be encountered, sometimes necessitating

surgical removal.

–No specific treatment unless removed for

some other reason, should serve well

indefinitely.

PHYSICAL INJURIES OF THE BONE

• Fractures of Jaws:

–Most common physical injury involving bone.

– It occurs during accidents such motor vehicles, fall form heights, sports, fights

etc.

– It may be of simple, greenstick, compound, comminuted or impacted.

–Fractures of Maxilla:

•These are more serious than mandible

fractures.

•Classified by Le Fort includes

•Le Fort 1 or horizontal #, also known as

floating # is characterized by separation

of body of the maxilla from the base of

the skull, below the level of zygomatic

process.

•Le Fort 2 or pyramidal #

is characterized by

vertical # through the

facial aspects of the

maxilla and extend

upward to the nasal and

ethmoid bones and

usually extends through

the maxillary sinus.

• Le Fort 3 or transverse # is a high level of # that extends across the orbits through the base of the nose and ethmoid region to the zygomatic arch. Bony orbit is #ed and the lateral rim is separated at the zygomaticofrontal suture. Zygomatic arch is #ed.

• Over view of all three fracture lines.

–Fractures of Mandible:

•Most common in road traffic accidents and physical violence.

• It most commonly involves the angle of mandible, which is followed by condyle, molar region, mental region and symphysis.

•Displacement depends on the direction of the line of #, muscle pull and the direction of force.

•Features are similar to other #s such as pain, abnormal mobility, lacerations, bleeding etc.

•Treatment includes reduction and immobilization like other #s.

•Complications are malunion, nonunion and fibrous union.

–Traumatic Cyst:

• It is pseudo cyst & an uncommon lesion in bone.

•Many theories have been proposed but the trauma-hemorrhage theory is widely accepted.

•According to the hemorrhagic theory, the clot breaks down and leaves an empty cavity within the bone.

•When cavity is opened surgically either a small amount of serosanguinous fluid, shreds of necrotic blood clot, fragments of fibrous connective tissue or nothing.

•Radiographically it reveals a rather smoothly outlined radiolucent area of variable size, some times with a thin sclerotic border, depending on the duration of the lesion.

• Focal Osteoporotic Bone-Marrow Defect of the Jaw:

–Occurs in angle of mandible, tuberosity etc.

–Unusual demand for blood production causes osteoporosis of marrow and even

thinning the cortex.

–Other theories include unusual healing of the extraction socket(mostly

associated with it).

• Surgical Ciliated Cyst of Maxilla:

–Develops after surgical entry into maxillary sinus(Cadwell-Luc operation) or due to obstruction of ostium.

–Majority of patients belong to middle age group with non-specific, poorly localized pain, tenderness or discomfort of maxilla.

–Filling defect is seen radiographically.

–Treated by enucleation

• Effects of Orthodontic Tooth

Movement:

–General principle in

orthodontic tooth

movement involves

resorption on pressure side

and deposition of bone on

tension side resulting in

tooth movement within the

bone.

•Tipping movement:

–The exact movements which a tooth will undergo and the exact position it will assume after the application of orthodontic force and the position of fulcrum around which the force acts.

–New bone is formed on the outer surface of labial cortex if pressure is applied labially to maintain the cortical thickness and prevent perforation of the cortex during tooth movement.

Other movements which follow the same pattern are torquing & rotation

–Extrusive tooth movement:

• It is similar to normal eruption.

•Movement consist in deposition or apposition of new bone spicules at the alveolar crest and at the fundus of the alveolus arranged in a direction parallel to the direction of force

–Intrusive or Depressive movement:

•Tissue changes result in opposite of extrusive tooth movement and new bone formation is minimal.

• Tissue reaction during retention period:

• During this period there is gradual reformation of the normal dense pattern of the

alveolar bone by apposition of bone around the bony spicules until they meet, fuse

and gradually remodel.

• The final remodeling and the attainment of absolute bone-tooth equilibrium

following orthodontic tooth movements involve an extremely slow process and is

responsible for orthodontic failure due to relapse during retention period.

• Studies have found that the deciduous tooth movement is followed by the permanent tooth germ.

PHYSICAL INJURIES OF SOFT TISSUES• Linea Alba:• It is a white line seen on the buccal mucosa extending from the

commissures posteriorly at the level of the occlusal plane. • Caused by physical irritation and pressure by the posterior

teeth. Seen bilaterally. Common in bruxism patient or clenching habit.

–Toothbrush Trauma:•This injury occurs to the gingiva and is produced by the tooth brush.•Appears as white, reddish or ulcerative lesions or linear superficial erosions, • involving marginal & attached gingiva of maxillary canine & premolar region.

•Traumatic Ulcer:

–It is caused by some form of trauma.

–This may be due to biting of mucosa, denture irritation, tooth brush injury, exposure of OMM to sharp tooth or carious lesion etc.

•Factitial Injuries:

–These are self-induced injuries. These may be habitual, accidental or may have psychogenic background.

• Lip biting or Cheek biting:

• These injuries are habitual or psychogenic.

• It involves holding, biting & tearing of the epithelium of lip, buccal mucosa or tongue, chewing of cheek or stripping of the epithelium using fingers or creating negative pressure by sucking the lips & cheeks.

–Intra & Perioral Piercing:

•Body piercing is the act of puncturing or cutting a part of the human body, creating an opening in which jewelry may be worn.

•Eye brow, ear, ala of nose, lip, tongue etc., are used.

•Complications include edema, hemorrhage and infection, mucosal or gingival trauma, chipped or fractured teeth, increase salivary flow, calculus build up, gingival recession etc.

• Denture injuries:

–Traumatic ulcer:

•Commonly results after insertion of a new denture.

•May be result of over extension of the flanges, sequestration of spicules of bone under the denture or a roughened or high spot on inner surface of the denture.

•These are small, painful,

irregularly shaped lesions

usually covered by delicate

gray necrotic membrane

and surrounded by

inflammatory halo.

–Generalized Inflammation:

• It occurs in patients who may or may not have a new set of dentures.

• It may not be due to allergy. In some cases it is due to Candidal infections.

•The mucosa beneath the denture becomes extremely red, swollen, smooth or

granular and painful. Multiple pinpoint foci of hyperemia involving maxilla

may occur.

•The redness of the mucosa is

rather sharply outlined &

restricted to the tissue

actually in contact with

the denture.

–Inflammatory (Fibrous) Hyperplasia:

•One of the most common tissue reactions to a chronically ill-fitting denture is the occurrence of hyperplasia of tissue along the denture borders.

•Characterized by the development of elongated rolls of tissue in the mucolabial or mucobuccal fold area into which the denture flange continuously fits.

• Inflammatory Papillary Hyperplasia:

–Unusual condition involving mucosa of palate mostly associated with ill fitting dentures. Often associated with chronic hyperplastic candidiasis

–The lesion presents itself as numerous, closely arranged, red, edematous papillary projections, often involving nearly all of the hard palate and imparting to it a

warty appearance.

• Denture Base Intolerance or Allergy:

–Plasticizers of the soft liners are cytotoxic and effect many cellular metabolic reactions in vitro.

–It is very rare.

–This reaction may

be due to sensitivity

to the monomer,

both regular &

self curing types.

• Mucous Retention Cyst:

–Generally conceded to be of traumatic origin.

–Usually results due to the obstruction of ducts of minor or accessory salivary glands.

–There may be chronic partial obstruction by small pieces of dental calculus or other products.

–These have been classified as:

1. An extravasation mucocele or

2. A retention mucocele (true retention cyst)

• Ranula:

–Mucocele but larger, which specifically occurs in the floor of the mouth in association with the ducts of the submaxillary or sublingual gland.

–It slowly enlarges painlessly on one side of the floor of the mouth.

–The mucosa may have a translucent bluish colour. It may sometimes herniates through mylohyoid muscle causing plunging ranula.

• Retention Cyst of Maxillary Sinus:

–It is uncommon and because of the possibility of confusing it with a variety of other lesions occurring in the same location

–Causative factors include sinusitis, allergy and sinus infection but these are without firm support.

• Sialolithiasis:

–A stone in the salivary ducts or glands is called sialolithiasis.

–They are formed by deposition of calcium salts around a central nidus.

–It can be complete or partial & may show recurrence. Many patients involved with major salivary gland reported with moderately severe pain , particularly just before, during and after meals owing to psychic stimulation of salivary glands.

–Maxillary Antrolithiasis:

•Defined as a complete or partial calcific encrustation of an antral foreign body, either endogenous or exogenous, which serve as nidus.

•Generally asymptomatic but may present with symptoms like pain, nasal obstruction &/or foul discharge & epistaxis.

Condition Diagnosis

Common sites of occurrence

Management

Linea Albaclinical Buccal mucosa Explanation and

reassurance, no specific treatment

required

Mucosal Biting Clinical Buccal mucosa, lip and lateral border of

the tongue

Explanation and reassurance, advice on habitual biting

Riga-Fede disease Clinical Tip or ventral surface of the

tongue

Extraction of neonatal teeth

Eosinophilic ulcer Biopsy Gingiva Spontaneous healing

Ulcers caused by self-mutilation or self-injury

Clinical Gingiva Psychological assessment and

counselling

Ulcers due to oral trauma in patients with congenital

insensitivity to pain

Clinical Lips and tongue Symptomatic treatment, prevent trauma from sharp

edges of teeth

Electrical and Thermal Burns Clinical Lips and tongue Surgical excision and reconstruction

Summary of oral mucosal traumatic lesions and their management Condition Diagnosis Common sites of

occurrenceManagement

Trauma associated with sexual practices

clinical Soft palate, lips Symptomatic management

Denture associated hyper keratosis

Clinical Alveolar ridge Elimination of irritation from the

denture

Denture associated ulcers Clinical Buccal and lingual sulci

Trim the denture to eliminate trauma

Inflammatory papillary hyperplasia

Clinical Palate Anti-fungal treatment, surgical

excision

Epulis fissuratum clinical Buccal sulcus Surgical excision and vestibuloplasty

–Radiation Injuries:

•The general term radiation is referred to two different forms of energy

–Electro magnetic radiation and

–Particulate radiation.

•General effects of radiation

–The cellular injury has been postulated to be due to a number of possible factors

•Toxic effect of protein breakdown products.

• Inactivation of enzyme systems.

•Coagulation or flocculation of protoplasmic colloids.

•Denaturation of nucleoproteins

• Effects of Radiation on Oral & Para oral tissues:

–Depend upon great number of factors such as the source, total amount, period of time of radiation administered, type of filtration & total area of tissue irradiated.

–There is bilateral parotitis, partial xerostomia and oral mucostitis following total body radiation.

• Effects on Skin:–Erythema is the earliest visible reaction and begins

within a few days after irradiation.–Altered sebaceous gland activity resulting in decrease

in secretions and cause dryness & scaling of the skin.–Superficial blood vessels become telangiectatic or

occluded.

• Effects on Oral Mucosa:

–Same as those as in skin with erythema and mucostitis

follows.

• Effects on Salivary Glands:

–Xerostomia is one of the most commonest and earliest

complaints of all.

–The loss of secretion may be a permanent condition or there

may be gradual return of salivation after several months.

• Effects on Teeth:–Radiation caries is most common problem after radiation.–Mostly due to altered changes in the salivary glands.–Developing tooth are particularly very sensitive to X-ray

radiation. –There may be complete cessation of odontogenisis or stunting

of growth of teeth depending upon the time of radiation

• Effects on Bone:

–Bone itself is relatively resistant to X-ray radiation, although osteoblasts are sensitive.

• There is lack of proper response to healing of radiation injuries in bone like other type of injuries leading to complications like osteoradionecrosis and longer the period between radiation and extraction less chances are there to develop osteoradionecrosis.

• Osteoradionecrosis:

–It is an acute form of osteomyelitis caused by damage to the intraosseous blood vessels & is characterized by a chronic, painful infection and necrosis accompanied by late sequestrum and some permanent deformity.

–There is lack of osteoblasts in turn lack the capacity to produce new bone.

• The walls of regional blood vessels are thickened by fibrous connective tissue resulting in devitalization of bone due to lack of reparative capacity.

• The devitalized bone is not demarcated and occurs throughout the entire irradiated area of bone.

• Factors leading to osteoradionecrosis is

–Irradiation of an area of previous surgery before adequate healing had taken place.

–Irradiation of lesions in close proximity to bone.

–A high dose of irradiation with or without proper fractionation

–Use of a combination of external radiation and intra oral implants

–Poor oral hygiene and continued use of irritants.

–Poor patient co-operation in managing irradiated tissues or fulfilling home care programs–Surgery in the irradiated area–Indiscriminate use of prosthetic appliances following radiation

therapy–Failure to prevent trauma to irradiated bony areas and –Presence of numerous physical & nutritional problems prior to

therapy.

CHEMICAL INJURIES OF ORAL CAVITY

• One of the most commonest reaction to drugs or chemicals is

the allergic phenomenon, the two main types of that are of

dental interest being

–Drug allergy or stomatitis medicamentosa and

–Contact stomatitis or stomatitis venenata.

• Non-allergic Reaction to Drugs and

Chemicals used Locally:

–Aspirin:

•Used by many people as local

abtundent for the relief of

toothache.

•Within a few minutes after

placement of the aspirin powder

there is burning sensation of

mucosa & the surface becomes

blanched or whitened in

appearance. Healing of painful

aspirin burn take a week or

more.

• Endodontic Materials:–Sodium Hypochlorite• It produces damage when injected beyond apex.•On contact with vital tissue it causes hemolysis & ulceration, inhibits neutrophil migration and damages endothelial and fibroblast cells.•Life threatening airway obstruction has been reported secondary to hypochlorite

extrusion.

–Hydrogen Peroxide:

•Similar to effects of hypochlorite.

• In addition causes irritation to the cementum & periodontal ligament leading to cervical root resorption.

• Non Allergic Reactions to Drugs & Chemicals Used Systemically:

–This reaction is often a part of a generalized epidermal reaction, but other times it occurs as a specific phenomenon apparently due to anatomic peculiarity.

–Arsenic:

•Occupational hazard, widely used in metal industry.

• Inflammation of OMM & severe gingivitis.

•Local contact produces ulceration & systemic poisoning causes excess salivation

• Bisphosphonate:

–It is a potent anti resorptive agent used in many diseases involving resorption.

–Osteonecrosis incidence is associated with bisphosphonate.

– Osteonecrosis of jaw

probably results from

the inability of

hypodynamic &

hypovascular bone

to meet an increased

demand for repair &

remodeling.

• Bismuth:

–Pigmentation of oral mucosa, particularly gingiva & buccal

mucosa is common oral feature in bismuth therapy

especially when receiving preparations containing metal

–The pigmentation appears as a bismuth line, a thin blue-

black line in the marginal gingiva is sometimes confined to

the gingival papilla. The pigmented granules consists of

sulphides.

• Dilantin Sodium:–Extensively used in the control of epileptic seizures.–Gingival hyperplasia is the side effect which can avoided with

good oral hygiene practices.–First noted as painless increase in size of the gingiva, starting

with enlargement of one or two interdental papilla.–The surface of gingiva shows an increased stippling & finally a

cauliflower, warty or pebbled surface.

• Lead:

–Lead poisoning(plumbism) occurs chiefly as an occupational hazard today but occasionally as acute or chronic nature.

–Manifested as serious GIT disturbances which include nausea, vomiting, colic and constipation.

–Peripheral neuritis may produce characteristic wrist-drop or foot-drop.

• Mercury:

–It may be of acute or chronic and acute form are serious.

–Chronic is characterize by gastric disturbances, diarrhea, excitability, insomnia, headache and mental depression.

–Increased salivation and metallic taste in mouth. Salivary glands may be swollen and tongue is also sometimes enlarged and painful. Hyperemia and swelling of the gingiva are occasionally seen.

• Acrodynia:

–It is mostly due to mercury poisoning in acute cases or as an idiosyncrasy to the metal. Source is mainly teething powder or mercury containing ointments, lotions or disinfectants.

–In young infants below the age of two years.

–The skin particularly of the

hands, feet, nose, ears & cheeks

become red or pink and has a

cold, clammy feeling.

•Silver:–Chronic exposure to silver compounds may occur as

occupational hazard or as a result of therapeutic use of silver compounds.

–Appearance of a slate-blue silver line along the gingival margins arising due to deposition of metallic silver & silver sulphide pigments is one of the earliest signs.

–Amalgam tattoo of OMM is a

relatively common finding in

dental practice, generally

occurring in four ways.

• Tetracycline:

–Discoloration of either deciduous or permanent teeth may occur as a result of tetracycline deposition during prophylactic or therapeutic regimes by pregnant woman or postpartum infant.

–The severity of the staining by tetracycline is determined by the stage of tooth development at the time of drug administration.

–Teeth affected appear to

have a yellowish or

brownish-gray

discoloration which is

most pronounced at the

time of eruption of teeth.

OCCUPATIONAL INJURIES OF THE ORAL CAVITY• They occur as a result of work or occupational activity.

OCCLUSAL TRAUMA• Occlusal changes can cause in the alveolar bone and

periodontal connective tissue both in the presence and in the absence of periodontitis.• Occlusion & local irritants are two factors in the etiology &

pathogenesis of periodontal disease.

• Acute trauma occurs when biting hard food substance or a high filling resulting in pain, sensitivity to percussion and slight mobility.• When excessive forces occur in different directions results in

widening of periodontal ligament.

• Chronic occlusal trauma is relatively more common than acute forms.• In this the PDL gradually becomes denser and the periodontal

space widens.

CONCLUSION

• As prosthodontist we should be able to diagnose the different conditions which lead to the trauma and treat the underlying cause.• All precaution should be taken to prevent injuries to the

patient during the treatment.• It is best advised to use proper preventive barriers such as

rubber dams to prevent chemical exposure during treatment and also careful handling of the materials during use.• Additional care should be taken while using rotary

instruments in the oral cavity. Instrument should be started and stopped in the cavity only to prevent injury to the adjacent soft tissues.• Sound knowledge and prompt remedies should be known to

the dentist if any mishaps occur in the clinic.

REFERENCES

•Shafer’s text book of Oral Pathology-6th Edition.• Iatrogenic injury of oral mucosa due to Chemicals: A Case report of formocresol injury and review - Girish M S, IOSR Journal of Dental and Medical Sciences Volume 14, Issue 4.• Traumatic Oral Mucosal Lesions: A Mini Review and Clinical Update- Ariyawardana Anura, OHDM - Vol. 13 - No. 2 - June, 2014.