This lesson will refer to non-carious tooth surface loss (sometimes referred to as tooth wear). In dental practice you will very frequently come across tooth surface loss (TSL), with most patients experiencing it to some degree; but when is it pathological?
Tooth surface loss can be physiological or pathological. These are distinguished by taking into account the patient’s age and the severity of tooth wear e.g. in a young person with severe TSL would be pathological, whereas in an older person with moderate TSL this may be physiological from normal use over the years.
There are 4 causes of tooth surface loss:
Tooth surface loss is often a multifactorial problem. The different causes often appear simultaneously which potentiate their effects. It is important to identify the etiological factors of tooth wear so that the patient can be advised of ways to manage it.
Note: Degradation refers to the fusion of tooth wear on occlusal/ incisal surfaces with tooth wear on a cervical area. This occurs in a late stage of wear. (8)
Tooth wear can expose the pulp but in adults this is very rare since the rate of wear is normally slow enough to allow sclerotic and reparative dentine to be formed. In these cases indirect pulp capping should be attempted and elective endodontics should be avoided because there is no bacterial invasion, unlike with caries.(8)
| Type | Presentation |
| Erosion | Primarily affects the cusps of posterior teeth and palatal of anterior teeth. Chipping of the thin enamel margins of incisors.Molar and premolar teeth show cupping of the cusps. Anterior teeth can show cupping of the incisal edges. These can merge across the oblique and marginal ridges to form a bowl shape. Mandibular molar teeth often most severely affected in this instance. Margins of restoration may stand proud of the natural tooth. |
| Attrition | Flat, well defined and demarcated.Shiny if active progression. Complementary facets often present on the opposing teeth. Primarily affects the cusps of posterior teeth and the incisal edges and palatal of anterior teeth. Tooth indentations on the tongue (scalloped tongue). Pronounced linea alba. Masseter hypertrophy.Reports of clenching and grinding (at night or during the day). |
| Abrasion | Cervical lesions. Specific shaped lesions on incisal edges from holding objects in between teeth. |
| Abfraction | Wedge-shaped cervical lesions. Likely to be present with signs of attrition. Most common in locations least protected by serous saliva. |
The methods of monitoring tooth surface loss described below are also important in its diagnosis:
In addition to a diagnosis, it is also important to assess whether the tooth wear is active or has stabilised. Below are the signs to look out for: (8)
| Active TSL | Stabilised TSL |
Sensitivity Shiny facets Little or no calculus Little or no staining Frothy or bubbly saliva Dry mucosa Mucosal changes Missing restorations | No sensitivity Matte/ Dull surfaces Significant calculus present Staining present Pooling saliva Moist mucosa Existing restorations intact. |
There are many indices for measuring tooth wear. Two of the most commonly used are described below:
| Score | Criteria (15) |
| 0 | No loss of enamel surface characteristics No loss of contour |
| 1 | Loss of enamel surface characteristics Minimal loss of contour |
| 2 | Loss of enamel exposing dentine for <1/3 of the surface Aka- Loss of enamel just exposing dentine Defect < 1mm deep |
| 3 | Loss of enamel exposing dentine for >1/3 of the surface Aka- Loss of enamel and substantial loss of dentine Defect < 1-2 mm deep |
| 4 | Complete enamel loss (excluding ‘halo’ of enamel) Pulp exposure or exposure of secondary dentine Defect > 2 mm deep |
An examination for erosive tooth wear should be part of every oral health assessment. One way to do this is to record a BEWE routinely.
| Score | Appearance |
| 0 | No erosive tooth wear |
| 1 | Initial loss of surface texture |
| 2 | Distinct defects, hard tissue loss <50% of surface area |
| 3 | Hard tissue loss >50% surface area |
| Risk level | Cumulative score of all sextants |
| None | ≤2 |
| Low | 3-8 |
| Medium | 9-13 |
| High | ≥14 |
| Cumulative score | Recommended management (13) |
| ≤2 | Repeat BEWE as part of each routine clinical examination |
| 3-8 | OHI, dietary assessment and adviceRoutine maintenance and recommend low abrasion toothpasteRepeat BEWE as part of each routine clinical examination |
| 9-13 | As above plus:Identify main aetiological factors in erosive tooth wearConsider additional fluoride measures/ strategies to increase resistance of the tooth surfaceAvoid placement of restorationsMonitor with study casts, clinical photographs, silicone impressions etcRepeat BEWE at least every 6-12 months |
| ≥14 | As above plus:Consider restorative intervention Consider specialist referral |
These techniques are then re-recorded at the appropriate recall, to identify whether the wear has progressed or stabilised.
In cases where a patient has TSL, you might think that there would be a decrease in OVD and excessive interocclusal space due to the loss of tooth structure. However, in many cases, these measurements remain unchanged. This has been found to be the case in 80% of patients with severe tooth wear. (18) This is predominantly caused by dento-alveolar compensation.
Dento-alveolar compensatory mechanisms assist in the establishment of an occlusion, that works by altering the alveolar bone and the axial orientation of the teeth. (19)
The management of the worn dentition is a very broad and detailed topic. This lesson will cover the fundamental concepts and management options (refer to the 3rd party references for further reading).
Some of this preventative advice has already been discussed in the conservative management of specific causes of tooth surface loss, but these are summarised to re-cap below: (20)
As we have not yet discussed splint therapy, this is covered in more detail below.
A full coverage hard acrylic splint may be used to disrupt the parafunctional habit of bruxism by causing tooth separation and changing the habitual pathway of closure into centric occlusion.
Two types of splints commonly mentioned are the Michigan and Tanner splints:
Michigan = Maxillary
Tanner = Mandibular
It has been advised that centric stops on each tooth, canine guidance and shared anterior guidance on protrusion should be included in the design to provide an ideal occlusion during wearing of the appliance.
Care should be taken when providing these splints to patients with erosive tooth wear, because acid may build up within the splint, exacerbate the problem. However, reservoirs can be incorporated within the design into which fluoride gels or alkali (milk of magnesia or sodium bicarbonate solute) can be added.
Although in many occasions a preventative approach is preferred, some cases of tooth wear indicate a restorative intervention: (23)
Before undertaking restorative treatment, always consider the prognosis of each tooth (periodontal, endodontic, restorative) as you would with any treatment. Where the tooth wear is generalised a tooth-by-tooth prognosis is required (see lesson).
When restoring the worn dentition, it is important to take the following factors into account: (21)
It is also advisable not to undertake restorative intervention if the TSL is still active (see diagnosis section). Preventative advice should be carried out first to stabilise the TSL, and restorative treatment carried out only when it has done so.Occasionally if underlying TSL factors cannot be controlled; in this case, it may help prevent wear to the tooth, but the restoration is likely to fail and need replacing in a matter of time. The patient should be warned of this. (8)
However, the exception to delaying treatment with preventative advice is in the situation of a young patient with an eating disorder. Preventative advice should still be given as the first course of action along with a GP referral (note: consent/ any safeguarding issues), but there is often rapid TSL with symptoms. Deferring the restorative treatment may have a significant effect on the patients oral health, aesthetics, and therefore psychological wellbeing. (24)
When restoring the worn dentition, the dentist must decide whether it is most appropriate to use the conformative or reorganised approach. This is a very large topic in itself so the fundamentals will be discussed in this lesson. However, it is first important to understand what the 2 approaches are: (26)
Placement of restorations without changing the existing occlusion. In order to do so, the occlusion (both dynamic and static) should be assessed prior to commencing treatment. This ensures that the contact points, and therefore occlusion, are the same after treatment as they were before.
The restoration of a dentition with the intention of changing the occlusion (to one that is ideal).
| Approach | Indications (27) |
| Conformative | Satisfactory OVD and adequate coronal tooth tissue for adhesive or conventional casting. Adequate occlusal clearance for the restorative material Reproducible occlusal contacts Localised tooth wear |
| Reorganised | Inadequate coronal tooth structure for adhesive or conventional casting Unsatisfactory OVD Inadequate occlusal clearance for restorative material. Unstable occlusion without reproducible contacts Generalised tooth wear |
If there is space for restorations when the patient is in ICP, then these may be provided relatively easily. However, if there is not space (often the case), then this must be created by one of the following methods:
| Method | Description (25) |
| Increasing the Occlusal Vertical Dimension (OVD) | Where there is tooth wear in one arch with no dento-alveolar compensation, the OVD will be decreased due to overclosure. The teeth can therefore be restored to the original OVD or normal resting face height which the patient normally tolerates. (3) Where there has been dento-alveolar compensation, the OVD can be increased to create space between the teeth. A hard occlusal splint to assess whether the patient can tolerate the new OVD or being ‘opened up’ can be used. The permanent restorations are then made to fit the new OVD. |
| The Dahl Effect | Useful when there is localised tooth wear e.g. palatal of maxillary incisors. The worn teeth are built up using composite which brings the other teeth out of occlusion. Over time (normally months) the other teeth erupt slightly to re-establish occlusion. |
| Enameloplasty | The adjustment of teeth in one or both arches to provide space. This is useful where only one tooth is needed to be restored, however removing tooth structure from an already worn dentition should be avoided due to risk of loss of vitality, sensitivity and loss of height of the teeth. |
| Distalization of the mandible | Used when there is a large slide between RCP and ICP. The mandible can be distalized by removing a premature contact found in RCP. This means that restorations can be placed in the new position negating the need to increase the OVD. |
| Crown lengthening | Used when there is insufficient crown height for definitive restorations. This is invasive and often bone is needed to be removed to protect the biological width. |
| Orthodontics | This is a conservative method; however, is very time consuming. Increasing the overjet or reducing the overbite can create space. Any alignment discrepancies can also be carried out. There is unreliability when intruding teeth and a risk of root resorption. |
| Elective root canal treatment and post crowns | When there is insufficient tooth height to retain a crown. In this case elective devitalisation with RCT and a post- crown may be considered. |
These can be carried out free hand or using a diagnostic wax up constructed by the lab.
The purpose of mock ups are to assess the aesthetics, occlusion and speech of the planned treatment prior to commencement. It allows the patient to make more of an informed decision and is important in consent.
The teeth are built up using unbonded composite on unprepared enamel without any matrix or impression serving as a guide. If the patient and clinician are both happy with the design, an impression or 3D scan is taken. This is so that the design can be replicated in a permanent material.
Please refer to the 3rdparty references for guidance on considerations on how to complete an intra-oral mock up e.g. smile design.
With a prescription, the technician will devise a diagnostic wax up to meet the aesthetic and functional requirements of the patient. This is where wax is placed onto a model to show the shape of the final restorations and should ideally be carried out so the occlusion is mutually protected.
An impression is taken in PVS or a vacuum formed PVC matrix is prepared so that the design can be transferred from the model to the teeth. Initially this is constructed in a provisional crown material so that the patient can visualise the results. This is carried out by filling the impression/ matrix with the provisional material and seating it in the mouth. Once the material is set, the impression/ matrix is removed and the flash/ excess trimmed away.
The intra-oral mock up is then assessed for speech, aesthetics and occlusion. At this stage it is beneficial for photographs to be taken so that the patient can think about the design and have input from friends and family.
Alternatively this can be achieved with digital smile technology but this is not included in the lesson.
The restorative options that exist are:
These have the same advantages and disadvantages as when used in other restorative situations. When considering composite restorations ensure that there is a ring of enamel present around the periphery of the tooth. This is also referred to as the ring of confidence because the bond strength to enamel is superior to that of dentine.
It is also important to keep in mind that composite is easily reparable if fractured, whereas crowns need preparation and when opposing natural tooth, some types of ceramic may potentiate the effects of tooth wear.
Please refer to other lessons on restorative materials for the advantages and disadvantages of each option as these will provide more in depth detail.
Alternatively, where severe wear is apparent with little supra-gingival tooth structure, there is also the option of an overdenture, often requiring RCT and abutment preparation. However, this is a whole topic in itself.
After treatment, a splint may be made for the patient to protect the restorative treatment. This may be in the form of a soft splint or a bi-laminar guard. These are both worn at night to prevent tooth wear from bruxism which may also result in damage to restorations.
Hopefully this lesson has provided an overview of the types of tooth wear and different management options. This is a very broad topic and you can read about it too many depths. As a general dentist you are expected to identify tooth wear and manage some cases, but it is important to recognise the limitations of your abilities/ experience and know when cases are beyond your competency and so are appropriate to refer.
Note: Tooth wear in children another large topic which is important to cover. Please refer to the 3rdparty references for information on this topic.
