A plea for the development of an universally accepted modular tooth wear evaluation system

Clinical and digital assessment of tooth wear

The aim of this study was to compare the assessment of tooth wear performed on digital models with the one conducted at the clinical examination. Seventy-eight volunteers (29 males and 49 females, age range 20-30 years) with at least 24 teeth, normal oral function, and a neutral transverse relationship were examined. During the clinical examination, dental wear was registered according to the Basic Erosive Wear Examination (BEWE) index. Subsequently, the BEWE index was blindly applied by two examiners on digital models obtained from the volunteers. Data were analyzed using weighted Cohen's kappa coefficient and correlation tests with a confidence interval of 95%. All volunteers showed signs of tooth wear. Anterior teeth showed increased severity of tooth wear than first molars. Early loss of tooth substance could be identified on the digital models, including in areas with challenging direct intraoral visual access. Approximately 50% of the scores based on clinical examination agreed with those based on examination of digital models (k = 0.543, p < 0.01). A moderate, positive correlation was observed between scores registered clinically and on digital models (Spearman's rho = 0.560, p < 0.001). Considering the rather low agreement between the clinical and digital scores, alternatives to using BEWE on digital models are needed.

Sex-specific reference values for the crown heights of permanent anterior teeth and canines for assessing tooth wear

OBJECTIVE

We propose sex-specific reference values for the clinical crown height of anterior teeth and canines.

MATERIAL AND METHODS

In this cross-sectional study, 1426 teeth were analysed from 169 undergraduate and postgraduate dental students (83 women and 86 men, median age 22 years). Teeth with worn or totally restored incisal edges, or gingival inflammation were excluded. Age, gender and body height were recorded and the degree of tooth wear was scored according to the quantification module of the Tooth Wear Evaluation System. The clinical crown heights of all anterior teeth and canines were measured from the gingival margin to the incisal edge with a digital calliper. Reference values for tooth groups were obtained at the percentiles 10, and expressed by sex if there was a significant difference between men and women.

RESULTS

Mean crown heights were bigger in men than in women for each tooth group (p = .028). Clinical crown heights showed sexual dimorphism at the 10^th percentiles for all tooth groups except for mandibular anterior teeth.

CONCLUSIONS

For assessing tooth wear, the sex-specific reference values for the clinical crown height of young adults Caucasoids range from 7.5 mm to 9.0 mm in women and from 7.5 mm to 9.5 in men.

Effect of masseter muscle activity during wakefulness and sleep on tooth wear

PURPOSE

To investigate the effect of masseter muscle activity during wakefulness and sleep on tooth wear.

METHODS

Sixteen participants with no or mild tooth wear (NMTW group) and sixteen participants with moderate-to-severe tooth wear (MSTW group) were enrolled. The severity of tooth wear was evaluated using the occlusal and incisal indices of the tooth wear index. Surface electromyography was performed to record the electrical activity of the left masseter muscle during wakefulness and sleep. Electromyographic activity was detected using an electromyographic threshold of 5% and 20% of maximal voluntary clenching (MVC). The total duration of electromyographic activity and bruxism episodes were calculated.

RESULTS

The mean ages of the NMTW and MSTW groups were 71.75 ± 7.61 years and 71.69 ± 7.49 years, respectively. The mean cumulative duration of electromyographic activity during wakefulness using a threshold of >5% MVC was 6.44 ± 4.52 min/h and 13.62 ± 10.08 min/h for the NMTW and MSTW groups, respectively (p=0.048). The mean total durations of electromyographic activity during wakefulness and sleep using a threshold of >20% MVC were 1.08 ± 1.70 min/h and 1.05 ± 3.02 min/h, respectively, in the NMTW group and 4.78 ± 6.37 min/h and 1.61 ± 1.79 min/h, respectively, in the MSTW group (p=0.048 and p=0.003, respectively).

CONCLUSION

These results suggest that masseter electromyographic activity during wakefulness and sleep may be related to the severity of tooth wear.

Tooth Wear Evaluation System (TWES) 2.0-Reliability of diagnosis with and without computer-assisted evaluation

BACKGROUND

Tooth wear is a multifactorial process, leading to the loss of dental hard tissues. Therefore, it is important to detect the level of tooth wear at an early stage, so monitoring can be initiated. The Tooth Wear Evaluation System (TWES) enables such a multistage diagnosis of tooth wear. The further developed TWES 2.0 contains a complete taxonomy of tooth wear, but its reliability has not yet been validated.

OBJECTIVES

The aim of the study was to examine in a randomised controlled trial (RCT) whether diagnoses made based on the TWES 2.0 are reproducible and whether this reproducibility is also achieved with computer-assisted diagnostics.

METHODS

44 dental students received extensive training in TWES 2.0 assessment and taxonomy. The students each evaluated at least 10 (of the present 14) anonymised patient cases using gypsum models and high-resolution intra-oral photographs according to TWES 2.0. One half initially evaluated on paper; the other half used dedicated software (CMDfact / CMDbrux). After half of the patient cases (5), the evaluation methods were switched (AB/BA crossover design). The diagnoses were then evaluated for agreement with the predefined sample solution.

RESULTS

Evaluation of agreement with the sample solution according to Cohen's kappa indicated a value of 0.46 for manual (traditional) evaluation; and 0.44 for computer-assisted evaluation. Evaluation of agreement between examiners was 0.38 for manual and 0.48 for computer-assisted evaluation (Fleiss' kappa).

CONCLUSION

The results of this study proved that the taxonomy of the TWES 2.0 has acceptable reliability and can thus be used by dentists. Accordingly, the system can be learned quickly even by untrained practitioners. Comparable results are achieved with computer-assisted evaluation.

The effect of pre-treatment levels of tooth wear and the applied increase in the vertical dimension of occlusion (VDO) on the survival of direct resin composite restorations

OBJECTIVES

To investigate the effects of the level of pre-treatment tooth wear and increasing the VDO on the performance of direct resin composite restorations for the rehabilitation of pathological tooth wear.

METHODS

Full-mouth (pre-treatment) grading was performed on digital greyscale scan records for 34 participants (35.3 ± 8.4 years) with signs of moderate-to-severe generalised tooth wear, using the Tooth Wear Evaluation System and the Basic Erosive Wear Examination. Each participant received full-mouth direct resin composite restorations, with increased VDO. The post-treatment increase in the VDO was determined. Recalls were planned after 1 month, and after 1, 3, and 5 years. Three 'levels' of restoration failure were described. The effects of the variables on the frequencies of restoration failure were calculated with a multivariable Cox regression, (p < 0.05).

RESULTS

1269 restorations were placed with a mean observation period of 62.4 months. Increasing the VDO by 1 mm significantly reduced the risks of all levels of anterior restoration failure (HR ≤ 0.62, p ≤ 0.025). A higher anterior BEWE surface score was associated with increased risks of Level 2- & 3- failures, (HR ≥ 1.29, p ≤ 0.019). Premolar restorations showed lower risks of Level 2- & 3- failure, compared to the molar restorations, (HR ≤ 0.5, p ≤ 0.005).

CONCLUSION

Levels of pre-treatment wear and the applied change in the VDO significantly affected failure risk.

CLINICAL RELEVANCE

Direct resin composite restorations for the rehabilitation of wear should be made as voluminous as possible, respecting the presenting biological, functional, and esthetic constraints.

3D Occlusal Tooth Wear Assessment in Presence of Limited Changes in Non-Occlusal Surfaces

The study aimed to develop an accurate and convenient 3D occlusal tooth wear assessment technique, applicable when surfaces other than the occlusal undergo changes during the observation period. Various degrees of occlusal tooth wear were simulated in vitro on 18 molar and 18 premolar plaster teeth. Additionally, their buccal and lingual surfaces were gently grinded to induce superficial changes and digital dental models were generated. The grinded and the original tooth crowns were superimposed using six different 3D techniques (two reference areas with varying settings; gold standard: GS). Superimposition on intact structures provided the GS measurements. Tooth wear volume comprised the primary outcome measure. All techniques differed significantly to each other in their accuracy (p < 0.001). The technique of choice (CCD: complete crown with 30% estimated overlap of meshes) showed excellent agreement with the GS technique (median difference: 0.045, max: 0.219 mm³), no systematic error and sufficient reproducibility (max difference < 0.040 mm³). Tooth type, tooth alignment in the dental arches, and amount of tooth wear did not significantly affect the results of the CCD technique (p > 0.01). The suggested occlusal tooth wear assessment technique is straightforward and offers accurate outcomes when limited morphological changes occur on surfaces other than the occlusal.

A comparative evaluation between the reliability of gypsum casts and digital greyscale intra-oral scans for the scoring of tooth wear using the Tooth Wear Evaluation System (TWES)

Background

The Tooth Wear Evaluation System (TWES) is a type of tooth wear index. To date, there is the lack of data comparing the reliability of the application of this index on gypsum cast records and digital greyscale intra‐oral scan records.

Objectives

A comparative evaluation between the use of gypsum cast records and digital greyscale intra‐oral scan records with the reliability of tooth wear scoring using the TWES amongst a group of patients with tooth wear.

Methods

Records for 10 patients with moderate to severe tooth wear (TWES ≥ 2) were randomly selected from a larger clinical trial. TWES grading of the occlusal/incisal, buccal and palatal/lingual surfaces was performed to determine the levels of intra‐ and interobserver agreement. Intra‐observer reproducibility was based on the findings of one examiner only. For the interobserver reproducibility, the findings of two examiners were considered. One set of models/ records were used per patient. Cohen's weighted kappa (κ_W) was used to ascertain agreement between and within the observers. Comparison of agreement was performed using t tests (P < .05).

Results

For the scoring of the of the total occlusal/incisal surfaces, the overall levels of intra‐ and interobserver agreement were significantly higher using the gypsum cast records than with the digital greyscale intra‐oral scan records, (P < .001) and (P < .001), respectively. For the overall buccal surfaces, only a significant difference was found in the intra‐observer agreement using gypsum casts, (P = .013). For the palatal/lingual surfaces, a significant difference was only reported in the interobserver agreement using gypsum casts, (P = .043). At the occlusal/incisal surfaces, grading performed using gypsum casts, culminated in significantly higher TWES scores than with the use of the digital greyscale intra‐oral scans (P < .001). At the buccal and palatal/lingual surfaces, significantly higher wear scores were obtained using digital greyscale intra‐oral scan records (P < .009).

Conclusions

The TWES can offer a reliable means for the scoring of wearing occlusal/incisal surfaces using gypsum casts. The reliability offered by digital greyscale intra‐oral scans for consecutive scoring was in general, inferior.

3D Method for Occlusal Tooth Wear Assessment in Presence of Substantial Changes on Other Tooth Surfaces

Early diagnosis and timely management of tooth or dental material wear is imperative to avoid extensive restorations. Previous studies suggested different methods for tooth wear assessment, but no study has developed a three-dimensional (3D) superimposition technique applicable in cases where tooth surfaces, other than the occlusal, undergo extensive morphological changes. Here, we manually grinded plaster incisors and canines to simulate occlusal tooth wear of varying severity in teeth that received a wire retainer bonded on their lingual surfaces, during the assessment period. The corresponding dental casts were scanned using a surface scanner. The modified tooth crowns were best-fit approximated to the original crowns using seven 3D superimposition techniques (two reference areas with varying settings) and the gold standard technique (GS: intact adjacent teeth and alveolar processes as superimposition reference), which provided the true value. Only a specific technique (complete crown with 20% estimated overlap of meshes), which is applicable in actual clinical data, showed perfect agreement with the GS technique in all cases (median difference: −0.002, max absolute difference: 0.178 mm³). The outcomes of the suggested and the GS technique were highly reproducible (max difference < 0.040 mm³). The presented technique offers low cost, convenient, accurate, and risk-free tooth wear assessment.

A systematic review of dietary acids and habits on dental erosion in adolescents

BACKGROUND

Dental erosion is the dissolution of dental hard tissues caused by acids of a non-bacterial origin. Dietary acids are considered the predominant and most controllable factor.

AIM

To synthesise the literature on the effects of dietary acids and habits on dental erosion in the permanent dentition of 10- to 19-year-old adolescents.

MATERIALS AND METHODS

An electronic literature search was undertaken in Cochrane, MEDLINE, CINAHL, Dentistry & Oral Sciences Source via EBSCOhost, and Embase with no restriction on the date of publication.

RESULTS

The initial search identified 449 articles, and 338 remained after removal of duplicates. Seventy-seven articles remained after screening of titles and abstracts, and 52 were eligible for the full-text review. A considerable variety of beverages, food, and dietary habits were reported as risk factors for dental erosion. The most consistent findings implicated the erosive potential of carbonated beverages and the consumption of acidic drinks at bedtime.

CONCLUSIONS

Although results were not consistent between cohort and cross-sectional studies, this review suggests certain dietary risk factors may contribute to dental erosion in adolescents. There is a need for more high-quality cohort studies to establish more conclusive evidence on the role of dietary acids and habits on dental erosion.

A study to investigate habits with tooth wear assessments among UK and non-UK dental practitioners

Aim To assess the habits of tooth wear risk assessment and charting using a tooth wear index, by UK and non-UK dental practitioners.Design A questionnaire-based evaluation.Methods Three hundred and two completed questionnaires were returned and the outcomes analysed using descriptives, Chi-squared test and Fisher's exact test in SPSS. Significance was inferred at p <0.05.Results Based on a sample of 297 responses, 81% agreed to the need to undertake risk assessment for all dental patients attending for a first-time consultation. Fifty-nine percent undertook risk assessments for 'new patients' previously identified with signs of severe tooth wear. The routine use of a clinical index to perform tooth wear charting was described by 13.5%, with 5% documenting the frequent use of the BEWE tool. While specialist dental practitioners or those with further post-graduate training were more likely to use a tooth wear index (p <0.05), there were no other significant relationships between any of the variables in the sample and the practising habits assessed.Conclusion This investigation alludes to good levels of professional awareness of tooth wear. However, the need for improvement with the actual undertaking of risk assessments for tooth wear and consistency with tooth wear assessment and charting was determined. The need for appropriate professional guidance for the undertaking of tooth wear assessments is supported by the outcomes of this investigation.

Diagnosing tooth wear, a new taxonomy based on the revised version of the Tooth Wear Evaluation System (TWES 2.0)

Background

Tooth wear is a multifactorial condition, leading to the loss of dental hard tissues. Physiological tooth wear is a slow process that normally does not lead to any subjective symptoms. When the condition progresses, it can become pathological, and several signs and symptoms may occur. The Tooth Wear Evaluation System (TWES) was described to implement a systematic diagnostic and management approach. Recently, management guidelines were presented in a European Consensus Statement (ECS) as well.

Objectives

To evaluate the TWES in practice and to integrate the principles described in the ECS in order to compose a renewed TWES 2.0 and a new taxonomy.

Methods

The TWES and the recommendations of the ECS were used by dental clinicians, in order to test its applicability in practice.

Results

Agreement was reached that the TWES 2.0 will use a stepwise approach, with a straightforward Tooth Wear Screening part and a more detailed Tooth Wear Status part. Also, the assessment of pathology from the ECS is incorporated in the TWES 2.0 (both classification and taxonomy).

Conclusions

In the TWES 2.0 is described that tooth wear is pathological if moderate/severe/extreme tooth wear is present, in combination with one or several described signs and symptoms. Aetiology can be assessed by findings that indicate a chemical and/or a mechanical cause. The taxonomy may help to identify situations in which preventive (restorative) interventions in early stages of tooth wear can be indicated. The reliability and validity of the adapted parts must be proven.

Associations between tooth wear and dental sleep disorders: A narrative overview

Objectives

Tooth wear is a common finding in adult patients with dental sleep disorders. The aim of this paper was to review the literature on the possible associations between tooth wear and the following dental sleep disorders: sleep‐related oro‐facial pain, oral moistening disorders, gastroesophageal reflux disease (GERD), obstructive sleep apnoea syndrome (OSAS) and sleep bruxism.

Methods

A PubMed search was performed on 1 June 2018 using MeSH terms in the following query: Tooth Wear AND (Facial Pain OR Temporomandibular Joint Disorders OR Xerostomia OR Sialorrhea OR Gastroesophageal Reflux OR Sleep Apnea Syndrome OR Sleep Bruxism).

Results

The query yielded 706 reports on tooth wear and the mentioned dental sleep disorders. Several associations between tooth wear and the dental sleep disorders were suggested in the literature. It could be concluded that: (a) tooth wear is associated with dental pain and/or hypersensitivity; (b) oral dryness is associated with tooth wear, oro‐facial pain and sleep bruxism; (c) GERD is associated with tooth wear, oro‐facial pain, oral dryness, OSAS and sleep bruxism; (d) OSAS is associated with oral dryness, GERD and sleep bruxism; and (e) sleep bruxism is associated with tooth wear.

Conclusions

Tooth wear is associated with the dental sleep disorders oro‐facial pain, oral dryness, GERD and sleep bruxism. The dental sleep disorders are interlinked with each other, which leads to indirect associations as well, and makes the consequences of each single condition difficult to disentangle. Knowledge of these associations is clinically relevant, but more research is needed to confirm their validity.

The Prevalence and Severity of Tooth Wear in Type 2 Diabetic Patients

Objective

To assess the prevalence and severity of tooth wear in type 2 diabetic patients.

Methods

Attendees at a diabetic clinic at Wiang Pa Pao Hospital in Chiang Rai province, Thailand, were invited to take part in this cross-sectional study. All participants were aged 35–74 and had type 2 diabetes. Participants were required to have been diagnosed with diabetes for at least three months. 179 subjects accepted a clinical oral examination and completed the questionnaire. Tooth wear was assessed clinically using the Smith and Knight Tooth Wear Index.

Results

The mean age of diabetic patients was 56.5 ± 7.8 years. The majority (44.1%) had diabetes more than 5 years. The average years of having had diabetes was 6.5 ± 6.3 years. The most prevalent type of tooth wear was attrition (99.4%). The prevalence of erosion, abrasion, and abfraction were 64.8%, 31.3%, and 7.3%, respectively. The majority of the tooth wear was moderate to high severity (62.1%). Erosion and abfraction showed significant association with age group (p < 0.05). Age group was significantly associated with the severity level (p=0.017). Mild tooth wear severity was the highest in age groups 35–44 and 45–54 (53.8% and 41.2%, respectively). Moderate tooth wear was the highest proportion in age groups 55–65 and 65–74 (52.2% and 44.0%, respectively). There were no significant differences between specific diabetic symptoms and types of tooth wear.

Conclusion

There was a high prevalence of tooth wear among diabetic patients. The role of prevention is vital in maintaining the integrity of the teeth and to avoid treating these worn teeth in diabetic patients.

Monitoring the progression of erosive tooth wear (ETW) using BEWE index in casts and their 3D images: A retrospective longitudinal study

OBJECTIVE

To determine if the Basic erosive tooth wear index (BEWE index) is able to assess and monitor ETW changes in two consecutive cast models, and detect methodological differences when using the corresponding 3D image replicas.

METHODS

A total of 480 pre-treatment and 2-year post-treatment orthodontic models (n = 240 cast models and n = 240 3D image replicas) from 120 adolescents treated between 2002 and 2013 at the Gent Dental Clinic, Belgium, were scored using the BEWE index. For data analysis only posterior sextants were considered, and inter-method differences were evaluated using Wilcoxon Signed Rank test, Kappa values and Mc Nemar tests (p < 0.05). Correlations between methods were determined using Kendall tau correlation test.

RESULTS

Significant changes of ETW were detected between two consecutive models when BEWE index was used to score cast models or their 3D image replicas (p < 0.001). A strong significant correlation (τb: 0.74; p < 0.001) was shown between both methods However, 3D image-BEWE index combination showed a higher probability for detecting initial surface changes, and scored significantly higher than casts (p < 0.001). Incidence and progression of ETW using 3D images was 13.3% (n = 16) and 60.9% (n = 56) respectively, with two subjects developing BEWE = 3 in at least one tooth surface.

CONCLUSIONS

BEWE index is a suitable tool for the scoring of ETW lesions in 3D images and cast. The combination of both digital 3D records and index, can be used for the monitoring of ETW in a longitudinal approach. The higher sensibility of BEWE index when scoring 3D images might improve the early diagnosis of ETW lesions.

CLINICAL SIGNIFICANCE

The BEWE index combined with digital 3D records of oral conditions might improve the practitioner performance with respect to early diagnosis, monitoring and managing ETW.

The Influence of Behavioural and Sociodemographic Risk Indicators on Erosive Tooth Wear in Flemish Adolescents, Belgium

Although Belgium has recently been ranked as the second highest consumer of soft drinks in Europe, no data on erosive tooth wear (ETW) are currently available. Therefore, the aim of this cross-sectional study was to determine the prevalence and associated risk indicators of ETW in adolescents residing in the region of Flanders, Belgium. Convenience sampling was used to recruit participants from different types of Belgian schools: general and vocational/technical education. Three calibrated dentists performed the dental examinations and a self-reported questionnaire was applied to evaluate risk indicators related with ETW. ETW was classified using the Basic Erosive Wear Examination (BEWE) index, and the overall prevalence was calculated using BEWE sum >0. The Kruskal-Wallis test, the Mann-Whitney U test, and logistic regression analysis were performed to evaluate frequencies and risk associations. From a total of 613 recruited adolescents (mean age: 15.1 years, SD: 0.8), 48.6% presented at least one affected tooth surface by ETW (BEWE sum >0), 14.4% (n = 88) scored BEWE sum >2, and the highest score obtained was BEWE sum = 8. Two predictive variables were found to have an association with ETW: vocational/technical type of education (OR: 1.49; 95% CI: 1.03-2.13) and frequent consumption of soft drinks (OR: 2.08; 95% CI: 1.38-3.14). In conclusion, ETW is a common condition presented with low severity among Flemish adolescents. Additionally, the frequent consumption of soft drinks and being part of a vocational/technical education appear to be risk indicators for ETW in this population. The latter indicates the need for specific orientated oral health promotion programmes for the prevention of ETW in Flemish adolescents.