Tooth wear | |
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Other names | Non-carious tooth substance loss |
Lower teeth shows signs of tooth wear likely caused by erosion | |
Specialty | Dentistry |
Tooth wear refers to loss of tooth substance by means other than dental caries. [1] Tooth wear is a very common condition that occurs in approximately 97% of the population. [2] This is a normal physiological process occurring throughout life; but with increasing lifespan of individuals and increasing retention of teeth for life, the incidence of non-carious tooth surface loss has also shown a rise. [3] Tooth wear varies substantially between people and groups, with extreme attrition and enamel fractures common in archaeological samples, and erosion more common today. [3] [4] [5]
Tooth wear is predominantly the result of a combination of three processes; attrition, abrasion and erosion. [3] These forms of tooth wear can further lead to a condition known as abfraction, [3] where by tooth tissue is 'fractured' due to stress lesions caused by extrinsic forces on the enamel. Tooth wear is a complex, multi-factorial problem and there is often difficulty identifying a single causative factor. [3] However, tooth wear is often a combination of the above processes. Many clinicians, therefore, make diagnoses such as "tooth wear with a major element of attrition", or "tooth wear with a major element of erosion" to reflect this. This makes the diagnosis and management difficult. [1] Therefore, it is important to distinguish between these various types of tooth wear, provide an insight into diagnosis, risk factors, and causative factors, in order to implement appropriate interventions. [1] Tooth wear evaluation system (TWES) may help determine the most likely aetiology of tooth wear. [6] Heavy tooth wear is commonly found on the occlusal (chewing) surface, but non-carious cervical lesions from tooth wear are also common in some populations. [7]
Multiple indices have been developed in order to assess and record the degree of tooth wear, the earliest was that by Paul Broca. [8] In 1984, Smith and Knight developed the tooth wear index (TWI) where four visible surfaces (buccal, cervical, lingual, occlusal-incisal) of all teeth present are scored for wear, regardless of the cause. [8] A more recent index Basic Erosive Wear Examination (BEWE) from 2008 by Bartlett et al., is now also in use. [9]
Attrition is loss of tooth substance caused by physical tooth-to-tooth contact. [2] The word attrition is derived from the Latin verb attritium, which refers to the action of rubbing against something. [2] Attrition mostly causes wear of the incisal and occlusal surfaces of the teeth. Attrition has been associated with masticatory force and parafunctional activity [2] such as bruxism. A degree of attrition is normal, especially in elderly individuals. [10]
Abrasion is loss of tooth substance caused by physical means other than teeth. [10] The term is derived from the Latin verb abrasum, which means ‘to scrape off’. [2] It tends to present as rounded ditching around the cervical margins of teeth, commonly described as ‘shallow’, concave or wedge shaped notches. [1] Causative factors have been linked to this condition and include vigorous, horizontal tooth brushing, using toothpaste with a relatively high RDA value (above 250), [11] pipe smoking or nail biting. It has also been shown that improper use of dental floss or Toothpicks can lead to wear on the interproximal (in-between) surfaces of the teeth. [2]
Erosion is chemical dissolution of tooth substance caused by acids, unrelated to the acid produced by bacteria in dental plaque. [1] Erosion may occur with excessive consumption of acidic foods and drinks, or medical conditions involving repeated regurgitation and reflux of gastric acid. [10] It is derived from the Latin word erosum, which describes the action ‘to corrode’. [2] This is usually on the palatal (inside) surfaces of upper front teeth and the occluding (top) surfaces of the molar teeth. [12] Dental erosion is rarely seen in the archaeological record, but certain cases have been described which suggested acidic fruits and/or plants were regularly consumed. [7]
Abfraction is a form of noncerious cervical lesion, where there is a loss of tooth substance at the cervical margins, purportedly caused by minute flexure of teeth under occlusal loading. This occlusal loading is one factor that interacts with chemical, biological,and behavioral factors in which result in this abfraction. [13] The term is derived from the Latin words ab and functio meaning ‘away’ and ‘breaking’ respectively. [2] Abfraction presents as triangular lesions along the cervical margins of the buccal surfaces of the teeth where the enamel is thinner and therefore, in the presence of occluding forces, is prone to fracture. [1] Whether abfraction exists or not is debated.
Tooth wear indices are useful tools for carrying out epidemiological studies and for general use in dental practices. [9]
The Basic Erosive Wear Examination was first described by Bartlett et al. in 2008. [14] The partial scoring system is based on the surface area affected. Within a sextant (i.e. teeth in mouth divided into 6 parts), the most severely affected tooth surface (buccal, occlusal or lingual/palatal)(see dental terminology) is recorded according to the severity of the wear (see Table 1). A cumulative score is then matched to a risk level and guidance for its management by a clinician. The management includes steps which identify and eliminate main aetiological factors, preventative treatment and also any operative and symptomatic intervention required by the patient. The frequency of repeating the index ranges from 6–12 months depending on the risk level of patients. [14]
BEWE Score | Clinical appearance description |
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0 | No erosive tooth wear |
1 | Initial loss of surface texture |
2 | Distinct defect, hard tissue loss <50% of the surface area |
3 | Hard tissue loss ≥50% of the surface area |
The Tooth Wear Index (TWI) (see Table 2) was developed by Smith and Knight in 1984. TWI scores each visible surface (buccal/B, cervical/C, lingual/L and occlusal-incisal/O/I) (see dental terminology). [15] This index has been widely used in epidemiological studies. [16]
Score | Surface | Criteria |
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0 | B/L/O/I | No loss of enamel surface characteristics |
C | No loss of contour | |
1 | B/L/O/I | Loss of enamel surface characteristics |
C | Minimal loss of contour | |
2 | B/L/O | Loss of enamel exposing dentine for less than one third of surface |
I | Loss of enamel just exposing dentine | |
C | Defect less than 1mm deep | |
3 | B/L/O | Loss of enamel exposing dentine for more than one-third of surface |
I | Loss of enamel and substantial loss of dentine | |
C | Defect less than 1-2mm deep | |
4 | B/L/O | Complete enamel loss- pulp exposure- secondary dentine exposure |
I | Pulp exposure or exposure of secondary dentine | |
C | Defect more than 2mm deep- pulp exposure- secondary dentine exposure |
Once the cause of tooth wear has been identified and a preventative regime has been put in place, the patient should be reviewed for 6–12 months to establish that the intervention has been successful before any active management is carried out. Once this has been achieved a decision needs to be made whether or not it is necessary to carry out restorative treatment or if it can simply be managed by non-invasive methods. [27]
Where restorative treatment is necessary, it must be decided whether to conform to the existing occlusion (typically for moderate wear, where only a few teeth are affected) or reorganise the occlusion (severe wear, unstable occlusion). Where the occlusion is reorganised, it can first be tested using a reversible method (i.e. a hard occlusal splint). A decision is made after full occlusal assessment including assessment of contacts in intercuspal position (ICP) and retruded contact position (RCP) as well as analysing casts articulated in a semi-adjustable articulator to use for a diagnostic wax up of any proposed restorative work. [28]
Active restorative management depends upon the location of the wear (localised or generalised), the severity of the wear, and the patient's occlusal vertical dimension (OVD), which may have changed as a result of tooth wear. There are three potential scenarios of tooth wear: [29]
Scenario 1 is relatively common, whereas scenario 2 is quite rare and tends to occur when the wear is rapidly occurring. Scenario 3 occurs due to a phenomenon called dentoalveolar compensation whereby the dentoalveolar tissues compensate for wear of teeth by increasing the bony support in order to maintain a constant OVD. This makes things difficult as there is no room to build the teeth back up to their original height without increasing the OVD. [29]
The options for restoring this loss in tooth height are: [30]
Pulp vitality must also be taken into consideration prior to treatment, when teeth have severe wear it is possible that they have become non-vital.
Bruxism is excessive teeth grinding or jaw clenching. It is an oral parafunctional activity; i.e., it is unrelated to normal function such as eating or talking. Bruxism is a common behavior; the global prevalence of bruxism is 22.22%. Several symptoms are commonly associated with bruxism, including aching jaw muscles, headaches, hypersensitive teeth, tooth wear, and damage to dental restorations. Symptoms may be minimal, without patient awareness of the condition. If nothing is done, after a while many teeth start wearing down until the whole tooth is gone.
A bridge is a fixed dental restoration used to replace one or more missing teeth by joining an artificial tooth definitively to adjacent teeth or dental implants.
In dentistry, a crown or a dental cap is a type of dental restoration that completely caps or encircles a tooth or dental implant. A crown may be needed when a large dental cavity threatens the health of a tooth. Some dentists will also finish root canal treatment by covering the exposed tooth with a crown. A crown is typically bonded to the tooth by dental cement. They can be made from various materials, which are usually fabricated using indirect methods. Crowns are used to improve the strength or appearance of teeth and to halt deterioration. While beneficial to dental health, the procedure and materials can be costly.
Hypodontia is defined as the developmental absence of one or more teeth excluding the third molars. It is one of the most common dental anomalies, and can have a negative impact on function, and also appearance. It rarely occurs in primary teeth and the most commonly affected are the adult second premolars and the upper lateral incisors. It usually occurs as part of a syndrome that involves other abnormalities and requires multidisciplinary treatment.
Abrasion is the non-carious, mechanical wear of tooth from interaction with objects other than tooth-tooth contact. It most commonly affects the premolars and canines, usually along the cervical margins. Based on clinical surveys, studies have shown that abrasion is the most common but not the sole aetiological factor for development of non-carious cervical lesions (NCCL) and is most frequently caused by incorrect toothbrushing technique.
Acid erosion is a type of tooth wear. It is defined as the irreversible loss of tooth structure due to chemical dissolution by acids not of bacterial origin. Dental erosion is the most common chronic condition of children ages 5–17, although it is only relatively recently that it has been recognised as a dental health problem. There is widespread ignorance of the damaging effects of acid erosion; this is particularly the case with erosion due to consumption of fruit juices because they tend to be seen as healthy. Acid erosion begins initially in the enamel, causing it to become thin, and can progress into dentin, giving the tooth a dull yellow appearance and leading to dentin hypersensitivity.
Abfraction is a theoretical concept explaining a loss of tooth structure not caused by tooth decay. It is suggested that these lesions are caused by forces placed on the teeth during biting, eating, chewing and grinding; the enamel, especially at the cementoenamel junction (CEJ), undergoes large amounts of stress, causing micro fractures and tooth tissue loss. Abfraction appears to be a modern condition, with examples of non-carious cervical lesions in the archaeological record typically caused by other factors.
Dentinogenesis imperfecta (DI) is a genetic disorder of tooth development. It is inherited in an autosomal dominant pattern, as a result of mutations on chromosome 4q21, in the dentine sialophosphoprotein gene (DSPP). It is one of the most frequently occurring autosomal dominant features in humans. Dentinogenesis imperfecta affects an estimated 1 in 6,000-8,000 people.
Dens evaginatus is a rare odontogenic developmental anomaly that is found in teeth where the outer surface appears to form an extra bump or cusp.
Talon cusp is a rare dental anomaly resulting in an extra cusp or cusp-like projection on an anterior tooth, located on the inside surface of the affected tooth. Sometimes it can also be found on the facial surface of the anterior tooth.
Dental attrition is a type of tooth wear caused by tooth-to-tooth contact, resulting in loss of tooth tissue, usually starting at the incisal or occlusal surfaces. Tooth wear is a physiological process and is commonly seen as a normal part of aging. Advanced and excessive wear and tooth surface loss can be defined as pathological in nature, requiring intervention by a dental practitioner. The pathological wear of the tooth surface can be caused by bruxism, which is clenching and grinding of the teeth. If the attrition is severe, the enamel can be completely worn away leaving underlying dentin exposed, resulting in an increased risk of dental caries and dentin hypersensitivity. It is best to identify pathological attrition at an early stage to prevent unnecessary loss of tooth structure as enamel does not regenerate.
Occlusal trauma is the damage to teeth when an excessive force is acted upon them and they do not align properly.
Occlusion, in a dental context, means simply the contact between teeth. More technically, it is the relationship between the maxillary (upper) and mandibular (lower) teeth when they approach each other, as occurs during chewing or at rest.
Cracked tooth syndrome (CTS) is where a tooth has incompletely cracked but no part of the tooth has yet broken off. Sometimes it is described as a greenstick fracture. The symptoms are very variable, making it a notoriously difficult condition to diagnose.
The Dahl effect or Dahl concept is used in dentistry where a localized appliance or localized restoration is used to increase the available interocclusal space for restorations.
In dentistry, overeruption is the physiological movement of a tooth lacking an opposing partner in the dental occlusion. Because of the lack of opposing force and the natural eruptive potential of the tooth there is a tendency for the tooth to erupt out of the line of the occlusion.
Tooth mobility is the horizontal or vertical displacement of a tooth beyond its normal physiological boundaries around the gingival (gum) area, i.e. the medical term for a loose tooth.
A complete denture is a removable appliance used when all teeth within a jaw have been lost and need to be prosthetically replaced. In contrast to a partial denture, a complete denture is constructed when there are no more teeth left in an arch; hence, it is an exclusively tissue-supported prosthesis. A complete denture can be opposed by natural dentition, a partial or complete denture, fixed appliances or, sometimes, soft tissues.
Non-carious cervical lesions (NCCLs) are a group of lesions that are characterised by a loss of hard dental tissue at the cementoenamel junction (CEJ) region at the neck of the tooth, without the action of microorganisms or inflammatory processes. These lesions vary in shape from regular depressions that look like a dome or a cup, to deep wedge-shaped defects with the apex pointing inwards. NCCLs can occur either above or below the level of the gum, at any of the surfaces of the teeth.
Occlusion according to The Glossary of Prosthodontic Terms Ninth Edition is defined as "the static relationship between the incising or masticating surfaces of the maxillary or mandibular teeth or tooth analogues".