Prevention of tooth wear Dr Ahmad Aljafari BDS, MFDS RCSEd, MSc, PhD

Lecture outline Definition of tooth wear Classification of tooth wear Prevalence of tooth wear Aetiology of tooth wear Aetiology of attrition Aetiology of abrasion Aetiology of erosion Overview of the next lecture

Definition of tooth wear

Definition of tooth wear “A general term that can be used to describe the surface loss of dental hard tissues from causes other than dental caries, trauma or as a result of developmental disorders.” Non-carious tooth surface loss (NCTSL)

Definition of tooth wear Physiological: - An irreversible process. A natural consequence of ageing. *No intervention is usually required* Normal vertical loss of enamel from physiological wear = 20-38 μm per annum.

Definition of tooth wear Pathological: Associated with functional or aesthetic concerns. Associated with symptoms of discomfort Disproportionate for the age of the patient. Deemed to be so severe that it may be of concern to the operator. *Intervention is required*

Classification of tooth wear

Types of tooth wear Attrition Abrasion Erosion Abfraction Demastication

Attrition - Loss of tooth substance due to tooth to tooth contact

Abrasion Loss of tooth substance due to mechanical friction from a foreign body. (E.g. toothbrush)

Erosion Loss of tooth substance by chemical means associated with extrinsic and/or intrinsic acid that is not produced by bacteria.

Abfraction Wedge-shaped defects observed at the cemento-enamel junction. Axial forces on the tooth stress in cervical region microfractures. Presents similarly to cervical abrasion.

Demastication Loss of tooth substance during mastication Combination of attrition and abrasion

However, in many cases, one of the processes predominates. Tooth wear is usually due to a combination of the afromentioned processes (erosion, attrition, abrasion). However, in many cases, one of the processes predominates.

Prevalence of tooth wear

Prevalence of tooth wear Up to 97% of adults affected by physiological tooth wear. Up to 7% exhibit pathological tooth wear. Variations in the threshold for considering tooth wear pathological have complicated the findings.

Prevalence of tooth wear Recent studies indicate erosion is now considered the major cause of pathological tooth wear. Up to 32% of adults might exhibit dental erosion.

Prevalence of tooth wear 5-6 year-old children (primary teeth) 50% showed signs of tooth wear. 25% had dentine involvement. 11 year-old children (permanent teeth) 25% displayed signs of erosion affecting the palatal surfaces of their maxillary incisors. 14 year-old children (permanent teeth) - 32% displayed signs of erosion affecting the palatal surfaces of their maxillary incisors.

Prevalence of tooth wear There has been a steady increase in reports of erosion especially in young adults, adolescents. This has been largely linked to the high consumption of fruit juice and carbonated drinks.

Tooth wear index

Aetiology of tooth wear

Aetiology of attrition Normal occlusal forces through life can cause physiological attrition, which is common and increases with age. Several factors can accelerate the process and cause pathological attrition: Parafunctional habits: Bruxism, clenching. Coarse or abrasive diet. Traumatic occlusion.

Aetiology of attrition Bruxism: “the habitual grinding, clenching, and gnashing of teeth during the day or night for non functional purposes”. Aetiology of bruxism not well understood: mostly related to stress and occlusal interferences. Uncertain whether it leads to attrition, or the other way around (attrition leads to bruxism).

Clinical presentation of attrition Wear facets on the occlusal surfaces of posterior teeth.

Clinical presentation of attrition Wear facets on the incisal edges of anterior teeth.

Clinical presentation of attrition Reduced vertical dimension in more severe cases. Increased dental sensitivity is rare, due to secondary dentin formation.

Aetiology of abrasion Associated with incorrect or over-vigorous tooth brushing with abrasive toothpastes or hard tooth brushes. The abrasivity of the toothpaste can be affected by: Amount of abrasive content. Type of abrasive used. Size of abrasive particle. Surface of abrasive particle. The chemical effects of the other toothpaste components.

Aetiology of abrasion Toothbrushing shortly after acid ingestion greatly increases the risk of abrasion. Oral habits related to objects, such as pipe-smoking, pen chewing, Miswak, playing wind musical instruments can also lead to abrasion.

Clinical presentation of abrasion Related to the foreign object causing the abrasion. Toothbrushing: V-shaped ditch on the labial- cervical region of teeth. Canines and premolars most commonly affected.

Clinical presentation of abrasion Pipes, wind instruments, seeds, nail biting or pen chewing: Notches on the incisal edges of anterior teeth

Clinical presentation of abrasion Toothpicks: Proximal surfaces of exposed roots Miswak use: Labial abrasion

Aetiology of erosion Demineralisation of enamel occurs once the oral environment pH goes below 5.5. Acids in the mouth originate from three main sources: Acidogenic bacteria Caries Ingested extrinsic acids Erosion Dislocated intrinsic acids Erosion

Aetiology of erosion The development of erosion is impacted by two properties of the ingested acid: pH Titratable acidity: the amount of alkali that needs to be added to an acid to bring it up to a neutral pH.

Intrinsic acids Gastric acids that enter the mouth as a result of reflux, vomiting or rumination. Gastric juice consists mainly of hydrochloric acid, making the juice highly acidic (pH 1.0-3.0).

Gastro-oesophageal reflux disease (GORD) “The passive or effortless movement of regurgitated gastric acid into the mouth.” Can be caused by a variety of underlying medical conditions/medications/behaviours.

Gastro-oesophageal reflux disease (GORD)

Gastro-oesophageal reflux disease (GORD) Affects up to 7% of adults daily, up to 33% every few days. Associated with heartburn, indigestion, and epigastric pain. However, 25% of adult patients with extensive palatal erosion may have GORD but not have any symptoms of reflux.

Gastro-oesophageal reflux disease (GORD) Especially common in those with neurological impairment (e.g. cerebral palsy). Not a common cause of erosion in children.

Vomiting The forceful propulsion of stomach and upper intestinal contents toward the mouth. Mediated by a host of physiological events, co-ordinated in the medulla. Spontaneous or self-induced.

Vomiting In children, chronic cyclic vomiting associated with medical conditions, such as: Irritable bowel syndrome. Motion sickness. Migraine. Epilepsy. Usually self-limiting and stop when the child reaches adulthood.

Vomiting Self-induced vomiting common in people with eating disorders (anorexia nervosa, bulimia nervosa). Bulimia affects 1-2% of the general population, Anorexia affects 0.1-0.2%/ Teeange females, from higher socio-economic classes, are the highest risk group.

Persistent vomiting in those patients can cause various oral complications, in addition to tooth erosion: Cervical caries Tooth sensitivity Periodontal disease Glossodynia Xerostomia Enlargement of the parotid glands Mouth ulcers Sore throat

Rumination The deliberate bringing back of food into the mouth to re-chew. Some have the ability to relax the lower oesophageal sphincter and reflux gastric contents into the mouth. Rare in occurrence. Should be considered in patients with unknown cause of erosive tooth wear.

Extrinsic acids The dentition can be exposed to extrinsic acids from a variety of sources: Drinks Foods Medications Recreational drugs Enviromental

Drinks There is a significant association between the consumption of soft drinks and dental erosion. Consumption close to bed time especially increases risk of erosion. Toothbrushing after ingestion of acids increases risk. Frequency of, rather than total intake, may be critical in the erosive process.

Foods The erosive potential of acidic foods is not as well understood as drinks. Research has shown frequent ingestion of citric fruits or berries may be associated with dental erosion.

Medication Some medicines are acidic: Vitamin C. Aspirin. Iron preparations. Other medications can cause vomiting or dry mouth, increasing the risk of erosion.

Recreational drugs The use of mood enhancing drugs such as ecstasy increases the risk of dental erosion (due to causing dry mouth).

Environmental factors Work related exposure to acids can result in dental erosion. Examples: Battery and sheet metal workers. Laboratory technicians. Competitive swimmers. Probably not common risks for dental erosion.

Aetiology of erosion Erosion, in a similar manner to dental caries, has a multifactorial aetiology. Examples of factors impacting the severity of erosion: Salivary flow rate. Salivary buffering capacity. Fluoride availability. Tooth structure and anatomy.

Clinical presentation of erosion Bilateral concave defects without the associated chalkiness normally seen in bacterial acid decalcification (surface looks glazed).

Clinical presentation of erosion

Clinical presentation of erosion Restorations projecting above the occlusal surface (proud restorations).

Clinical presentation of erosion Cupping of tooth cusps and incisal edges in more severe cases.

Clinical presentation of erosion Extrinsic erosion is evident of the labial surface of maxillary teeth. Intrinsic erosion is evident on the palatal surface of maxillary teeth. Perimolysis: erosive lesions on the palatal aspect of maxillary teeth as a result of chronic vomiting. The tongue protects the lower teeth while projecting the acids towards the palatal surface of the maxillary teeth.

Next lecture History, examination, and diagnosis of patients with tooth wear. Prevention of tooth wear Overview of management of patients with tooth wear Discussion

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