Tooth wear – Background
- In a European study by Bartlett et al (2013), buccal and lingual tooth wear in adults aged 18-34 years was common and affected more than 25% of this population. The UK had the highest levels of tooth wear in Europe.
- The Basic Erosive Wear Examination (BEWE) has been recommended as a tool for screening tooth wear and may be used in daily practice (Bartlett 2010). This assesses wear above or below 50% for each surface. A 4-point scale is used (0, 1, 2 and 3). All teeth are examined and the most severely worn surface in a sextant is scored. Other ways of measuring/monitoring tooth wear include casts and scanning.
- Erosion is a significant cause of tooth wear and is on the increase.
- An interesting study in Alabama (Reddy 2016) looked at the erosive potential of a range of soft drinks. They found that many of the drinks had a pH low enough to cause erosion, while results of recent work have indicated that carbonated drinks were more erosive than non-carbonated drinks and rosé sparking wine/champagne seemed to be the worst!
- Other causes of erosive tooth wear should not be forgotten and include: anorexia, bulimia, voluntary reflux phenomenon, pregnancy sickness, alcohol-induced vomiting and GORD.
- Signs of erosive activity include: sensitivity, loss of surface anatomy, cupped surfaces of anterior teeth, incisal translucency and loss of palatal enamel. Often unstained surfaces show active erosive tooth wear. If the dentine surface is stained, there has been sufficient time for the teeth to take up stains and therefore urgency of treatment decreases.
Tooth wear – Prevention
- Preventive advice for patients with an erosive element to their diet should include: reduce the amount and frequency of intake, avoid “frothing” or swishing drinks, avoid brushing teeth at least 30 minutes after drinking, chill the drink and avoid such drinks before bedtime.
- There is also increasing evidence that some toothpastes may help. For example, Oral-B Pro-expert™ has been designed to provide protection against erosion (IDJ 2014). It contains sodium hexametaphosphate, no abrasive particles and the stannous fluoride complex forms a long-lasting, acid-insoluble shield around teeth.
Treatment of worn teeth – Principals
- In general, the treatment of tooth wear with a direct restoration is a better option than reducing the tooth for a crown i.e. treatment of tooth wear using extreme tooth wear by a turbine drill is usually not the most appropriate option! Iatrogenic (“dentistogenic”) injury to the dental pulp is a significant problem in clinical dentistry, according to Bergenholtz, and pulpal damage following crown preparation is not uncommon (Saunders & Saunders 1998). Therefore, minimally invasive additive methods should be employed where possible.
- There are many other reasons to adopt a minimal intervention approach including the fact that patients like it (if you advise them of your philosophy) and we now have materials to make this work.
- When treating tooth wear patients must be advised that the treatment is to protect their worn and wearing dentition, not primarily to improve the appearance of their teeth.
- The Dahl concept can be used to obtain space for the restoration of worn teeth (Dahl et al 1975). Patient selection is important: ensure there are no TMJ problems, there is no periodontitis, teeth have no mobility, oral hygiene is satisfactory and there is sufficient tooth substance for bonding.
- Dentine bonding is now reliable and effective. Selective etching of enamel is a good idea (Peumans et al 2007) and universal bonding materials containing MDP are increasing in popularity.
- Direct composite restorations have distinct biological advantages compared with crowns and for the majority of patients they perform well, offer a high degree of patient satisfaction and require an acceptable degree of maintenance (Poyser et al 2007, Hemmings et al 2000, Redman et al 2003, Gow et al 2002).
Treatment of worn teeth – Practical tips
- If the treatment of tooth wear is new to you, start off with simple non-aesthetic cases e.g palatal build-ups.
- Don’t forget to ask patients about bleaching before you start the build-ups!
- If using the Dahl approach, your patient information leaflet should include: chewing on the back teeth may not be possible for 3-6 months so food should be cut into small pieces, lisping may occur for a few days, front teeth may be a little tender to bite on for a few days and if there are other fixed restorations in the posterior dentition they may require replacement (cost implications should be discussed). Regarding the longevity of the restorations: there is potential for the restorations to debond, chipping may occur and margins of the restorations may require occasional polishing.
- When treating tooth wear with composite resin: ensure you have a sufficient number of shades and translucencies, ensure the material has good polishability and non-slump/non-sticky materials facilitate easy freehand placement.
- When shade taking, it can be helpful to sample the material on the tooth and light cure.
- When layering composite, the importance of the correct thickness of each layer should not be underestimated.
- Ensure the marginal ridges you create are at the same height as adjacent teeth before shaping the restoration.
- Remember shape is more important than the shade. Make thick/wide incisal edges particularly in edge to edge occlusions so that guidance is flat and composite is in compression, use the available labial surfaces of upper incisors as a ferrule to improve resistance to torqueing forces on the composite, keep palatal guiding surfaces shallow to minimise sheer forces on the composite and build-up one tooth at a time. Top Spin diamond T2 and T3 burs can be used to shape posterior composites.
- When restoring teeth, symmetry of the central incisors is crucial to success. When assessing the width/length ratios of normal clinical crowns of the maxillary anterior dentition, there is wide variability but the mean width/height ratio appears to be around 0.80 (Sterrett 1999). The Golden Proportion has less relevance than previously thought.
- To check the occlusion, always use articulating paper that is <40 µm
- BisCover is useful to provide a glazed finish with zero oxygen inhibition later.
- Polishing tools: Soflex discs, Soflex Diamond Spiral, Hi-Luster (Kerr) using the blue (aluminium oxide) first then the grey (plastic impregnated with diamond powder) and Mycerium Shiny paste.
- Any restoration in the wrong environment will fail. The importance of optimal oral hygiene should be emphasised. The new Oral-B Gum and Enamel Repair can be useful toothpaste for this group of patients.
These notes have been derived from an Up To Date Event kindly sponsored by Oral B.