NON-CARIOUS NON-CARIOUS LESIONS.LESIONS.

Dr. Javeria Ali KhanLecturerDepartment of Operative Dentistry.

Wear: Damage to a solid surface, generally involving progressive loss of material, due to relative motion between the surface and a contacting substance or substances.

Tooth wear: Surface loss of dental hard tissue other then by caries or trauma and is a natural consequences of ageing.

TYPES OF TOOTH WEAR. Erosion (Corrosion). Attrition. Abrasion. Abfraction.

EROSION. Definition: It is defined as the loss of dental

hard tissue as a result of chemical process not involving bacteria.

Types of tooth erosion:

1- Regurgitation erosion.2- Dietary erosion.3- Industrial erosion.

REGURGITATION EROSION.

Definition: The erosive distruction of teeth caused by

frequent exposure of gastric acid to teeth.

Sites: Palatal surface of maxillary anterior teeth. Occlusal and buccal surfaces of mandibular

teeth.

REGURGITATION EROSION.Etiology:

1- Digestive disorders including hiatus hernia and chronic indigestion.

2- Anorexia and bulimia nervosa (Perimolysis, evident on maxillary palatal surfaces).

3- Morning sickness associated with pregnancy.

4- Voluntary regurgitation.

ORAL MANIFESTATIONS.ORAL MANIFESTATIONS.

Tooth enamel erosion: teeth are bathed in gastric acid during Tooth enamel erosion: teeth are bathed in gastric acid during vomiting leading to decalcificationvomiting leading to decalcification

Tooth sensitivity to temperaturesTooth sensitivity to temperatures Parotid gland (sialadenosis) or submandibular gland Parotid gland (sialadenosis) or submandibular gland

enlargement: can be disfiguringenlargement: can be disfiguring Erythema of the oral mucosaErythema of the oral mucosa Soreness in mouthSoreness in mouth CheilosisCheilosis

DIETARY EROSION.

Definition: “It is the loss of dental hard tissue by

intake of acidic foods and drinks.”

Site: Labial surface of maxillary teeth.

THE DRINKS WE SHOULD TAKE OR NOT ?

DIETARY EROSION.

Etiology: Citrus fruits and fruit juices (contains

citric acid). Pickles and food containing vinegar

(contains acetic acid). Carbonated and energy drinks

(contains carbonic acid).

ETIOLOGY. Alcohol. Salad dressings. Effervesecent vitamin C tablets. Acidic candies. Herbal tea.

DIETARY TOOTH EROSION.

HOW DOES SALIVA HELP IN PROTECTING AGAINST EROSION? Dilutes and clears potentially erosive

agents from the mouth. Buffers dietary acids. Formation of Pellicle which protects the

enamel from demineralization by dietary acids.

Provide calcium and phosphate which is necessary for remineralization.

WHAT ADVICE SHOULD WE GIVE TO THE PATIENTS ? Diminish consumption of acid foods and

beverages. Finish meal using neutral food rather

then acid foods. Drink acid beverages quickly or through

a straw do not swish around. Rinse using water after acid

consumtion.

HOW CAN DENTAL EROSION BE PREVENTED ? Use soft or medium type of tooth brush. Low abrasive fluoride containing

toothpaste. No tooth brushing immediately before

and after taking acidic food. Regular visits to dentist.

INDUSTRIAL EROSION.Definition:

“ It is the dissolution of dental hard tissue due to industrial processes which produces acid fumes and droplets.”

Sites:

Labial surface of maxillary anterior teeth and may also cause pitting.

INDUSTRIAL EROSION.Effected indivisuals: Battery manufacturers. Wine tasters. Chemical and pharmaceutical company

workers. Soft drink manufacturers. Dyers. Tin factory workers ( tartaric acid).

RADIOGRAPH SHOWING ERODED TEETH.

ATTRITION.

Definition: It is the physical wear of one tooth

against other or tooth against restoration or prosthesis.

Sites: Incisal and occlusal surface of teeth.

ETIOLOGY OF ATTRITION. Bruxism. Associated with snuff chewing. Associated with bettel nut and pan

chewing. Associated with hypertensive patients. Associated with poor prosthesis and

poor restorations.

ATTRITION DUE TO BRUXISM.

ABRASION.Definition: It is the physical wear of dental hard

tissues from external agents.

Site: Neck of labial surface of anterior teeth. Neck of buccal surface of posterior

teeth.

ETIOLOGY OF ABRASION. Hard tooth brushes or excessive use of other

cleaning aids. Abrasive tooth pastes and tooth powders

(smokers tooth powder). Habits such as thread biting and pipe

smoking (can cause notches in the incisal edges).

Snuff chewing. Pan and bettel nut eating.

TOOTH BRUSH ABRASION.

ABFRACTION.

Definition: It is the microstructural loss of tooth

substance in areas of stress concentration.

Site: Cervical region of teeth.

ABFRACTION ETIOLOGY. These lesions appear to result from

occlusal loading forces, frequently have a crescent form along the cervical line where the enamel is brittle and fragile.

ABFRACTION.

CONSEQUENCES OF PATHOLOGICAL TOOTH WEAR.

Exposure of dentine on buccal and lingual surfaces.

Notched cervical surfaces. Exposure of dentine on incisal and

occlusal surfaces resulting in loss of dentine producing a cupped appearance.

Restoration project above the tooth surface as they do not erode.

Exposure of reparative dentine or pulp. Causing sensitivity. Pulpitis and then later on loss of vitality. Inability to contact between incisal and

occlusal surfaces during mandibular movements.

Reduction in length of teeth.

COMBINED MECHANISM OF TOOTH WEAR.

1- Attrit ion- abfraction.

Attrition- abfraction is the joint action of stress and friction when teeth are in tooth-to-tooth contact, as in bruxism or repetitive clenching

2- Abrasion-abfraction. Abrasion-abfraction is the loss of tooth substance

caused by friction from an external material on an area in which stress concentration due to loading forces may cause tooth substance to break away. Such a synergistic tooth-destructive effect may be observed cervically when toothbrushing abrasion exacerbates abfraction to produce wedge-shaped lesions. The critical roles of both toothbrushing abrasion and occlusal loading of an anatomically vulnerable zone may be one reason why such lesions are limited almost exclusively to the buccal and labial cervical areas of teeth

3- Erosion-abfraction: Corrosion-abfraction is the loss of tooth

substance due to the synergistic action of a chemical corrodent on areas of stress concentration. This physicochemical mechanism may occur as a result of either sustained or cyclic loading and leads to static stress corrosion or cyclic stress corrosion.

Static stress corrosion: Static stress corrosion is the loss of tooth

structure owing to the action of a corrodent on an area of sustained stress. This may occur during clenching. Static stress corrosion may be observed as demineralization that occurs around orthodontic appliances in the presence of a corrodent.

CORROSION ABFRACTION.

Cyclic (fatigue) stress corrosion. Cyclic stress corrosion is the loss of tooth structure

due to the action of a corrodent in an area of concentrated stress during cyclic loading. This combination of mechanisms could occur during mastication, as seen among patients who engage in fruit mulling as dentinal invaginations, but is seen most strikingly among patients who brux in the presence of endogenous (for example, GERD) or exogenous (carbonated soft drinks) corrodents. In such situations, tooth substance may be lost rapidly and extensively.

Attrit ion-corrosion: Attrition-corrosion is the loss of tooth

substance due to the action of a corrodent in areas in which tooth-to-tooth wear occurs. This process may lead to a loss of vertical dimension, especially in patients with GERD or gastric regurgitation. An occlusal or incisal pattern of wear develops.

Abrasion-corrosion. Abrasion-corrosion is the synergistic activity of

corrosion and friction from an external material. This could occur from the frictional effects of a toothbrush on the superficially softened surface of a tooth that has been demineralized by a corrosive agent. Teeth that are out of occlusion could be affected by this mechanism and develop cervical lesions, since they frequently extrude, thus exposing the vulnerable dentin. Similarly, gingival recession may expose the cementum and dentin to this odontolytic process.

Biocorrosion (caries)-abfraction: Biocorrosion (caries)-abfraction is the pathological

loss of tooth structure associated with the caries process, where an area is micromechanically and physicochemically breaking away due to stress concentration. A common site for this synergistic activity is the cervical area of the tooth, where it may be manifested as root or radicular caries. The combined mechanisms of static stress corrosion and cyclic (fatigue) stress corrosion can account for the rapid odontolytic progression of these types of carious lesions.

BIOCORROSION ABFRACTION.