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

Intraoral scanner-based monitoring of tooth wear in young adults: 36-month results

OBJECTIVES

The study continues our longitudinal observation of wear aiming to further monitoring of progression and lesion morphology and to identify relationships with assumed aetiological factors.

MATERIALS AND METHODS

Molars (FDI #36 or #46) of 74 participants (23.8 ± 2.2 years) were scanned (Trios 3, 3Shape) at the third follow-up (T3; observation period 1,111 ± 10 days). Data sets from T3, T2 (24-month follow-up) and T1 (12-month follow-up) were superimposed with baseline in a 3D analysis software (GOM Inspect). Wear was quantified as maximum vertical tissue loss (µm; median, 95% CI) in various occlusal areas (4/5 cusps and 2 ridges). Morphologies were classified into cupping (C), facet (F), and combined cupping-facet (CF). Aetiological factors were assessed with questionnaires.

RESULTS

Wear increased at T3 significantly at low rates in all areas of the occlusal surface (median between 7.0 (4.0;10.5) and 9.5 (6.0;15.0) µm). There was a clear trend for higher loss values in males, but no association with other factors such as nutrition. C and CF showed significantly higher loss values than F. Areas without initial wear developed F first, which either persisted or developed into C and CF.

CONCLUSIONS

Wear continued at low rates with C/CF morphology and sex as significant factors. Cupped lesions seem to develop from facets and thus may not be a valid diagnostic criterion for erosive tooth wear.

CLINICAL RELEVANCE

Wear is a cumulative process that apparently follows complex mechanisms that cannot be conceptualized in simplified terms; C and CF may be indicators for higher progression rates.

Intraoral Scanning for Monitoring Dental Wear and Its Risk Factors: A Prospective Study

Dental wear arises from mechanical (attrition or abrasion) and chemical (erosion) factors. Despite its prevalence and clinical significance, accurately measuring and understanding its causes remain challenging in everyday practice. This one-year study with 39 participants involved comprehensive examinations and full-arch intraoral scans at the start and after 12 months. Volume loss exceeding 100 µ on each tooth's surfaces (buccal, lingual/palatine and incisal/occlusal) was measured by comparing three-dimensional scans from both time points. This study also assessed factors such as abrasion and erosion through clinical exams and questionnaires. There were no significant differences in dental wear in participants with sleep bruxism. However, noticeable wear occurred in the front teeth of those with waking bruxism and joint-related symptoms. Increased wear was associated with frequent consumption of acidic drinks, regular swimming, dry mouth, nocturnal drooling and heartburn, while no significant wear was found in patients with reflux. The used methodology proved effective in accurately assessing the progression of dental wear, which is important as many patients may initially be asymptomatic. The variability observed in dental wear patterns underscores the need to develop specific software applications that allow immediate and efficient comparison of wear areas based on extensive analysis of patient databases.

Detection of Erosive Changes on Smooth Surfaces with and without Orthodontic Brackets Using an Intraoral Scanner-An In Vitro Study

BACKGROUND

Consumption of acidic beverages favours development of erosions. Modern diagnostic methods are required to detect erosions at an early stage. This study aimed to evaluate the suitability of an intraoral scanner (IOS) for detection of erosive changes on smooth surfaces adjacent to orthodontic brackets.

METHODS

Orthodontic metal brackets were attached to the buccal surfaces of 58 extracted permanent human teeth. Teeth were randomly divided into groups: A = 6% citric acid, B = Coca-Cola, C = Redbull, D = Powerade, E = Control, no acid exposure. Teeth were exposed to acid in three erosion cycles, followed by rinsing and brushing. Scans of teeth were performed at baseline and after each erosion cycle and enamel loss was measured. Quantitative light-induced fluorescence (QLF) measurements were performed as reference standard.

RESULTS

Significant substance loss was measured in all acid groups after the second and third erosion cycle (p < 0.0001). Correlation between scans and QLF were significant (p = 0.001).

CONCLUSIONS

With IOS, it was possible to detect and quantify enamel erosion at smooth surfaces with and without orthodontic brackets after a short exposure time. Considering the limitations of in vitro results, the use of IOS can be a promising digital tool to detect and monitor erosive enamel changes during fixed orthodontic treatment.

Erosion-inhibiting and enamel rehardening effects of different types of saliva

OBJECTIVES

The objective of this study was to assess the effects of in situ saliva compared to in vitro human saliva, with or without mucin, on inhibiting erosion and promoting enamel rehardening.

DESIGN

Bovine enamel blocks were randomly distributed into groups (n = 23): Gsitu (human saliva in situ), Gvitro (collected human saliva) and GvitroM (collected human saliva with mucin). The enamel blocks underwent a 2-hour period for the formation of salivary pellicle, based on the assigned groups. Subsequently, they were subjected to three erosive cycles, each of them consisting of an erosive challenge (immersion in 0.65 % citric acid, pH 3.5, 1 min) and saliva exposure (immersion in situ or in vitro saliva for 2 h). Microhardness measurements were performed at each cycle, after each experimental step (erosive challenge and exposure to saliva).

RESULTS

After the first demineralization, in vitro saliva groups presented greater hardness loss, with no statistical difference between GVitroM and GVitro. After the third erosive demineralization the in situ saliva resulted in less hardness loss compared to the first demineralization. In relation to surface hardness recovery, there was no difference among types of saliva but there was a decrease in hardness as the cycles progressed.

CONCLUSION

Saliva groups had different behaviors between the first and third demineralization, being similar after the third cycle in terms of hardness loss. Regarding hardness recovery, all saliva promoted enamel gain, but there was a gradual decrease with the progression of the cycles.

Erosive Tooth Wear in Subjects with Normal Occlusion: A Pioneering Longitudinal Study up to the Age of 60

The aim of this study was to assess the erosive tooth wear (ETW) at early and mature adulthood in subjects with natural normal occlusion. The sample consisted of 23 untreated subjects with normal occlusion. Dental models were taken longitudinally from the same subjects at 13 (T0), 17 (T1) and 60.9 years of age (T2) at a university. Evaluation of ETW was performed using a modified Basic Erosive Wear Examination (BEWE) index. Interphase changes were evaluated using Friedman and Dunn's test. Ordinal logistic regression was used to assess the influence of sex, dental arch, tooth and dental surfaces on the erosive tooth wear. Linear regression was used to evaluate whether the ETW degree at T1 could discriminate the degree of ETW at T2. The significance level adopted was 5%. ETW showed a significant increase with aging. The median ETW index at T0, T1 and T2 was 2, 4 and 7, respectively. ETW was greater in males in the incisors and canines and on the incisal/occlusal and lingual tooth surfaces. No significant differences were found between the maxillary and mandibular arches. Subjects with severe ETW at mature adulthood had greater tooth wear at age 17. In conclusion, ETW significantly increased during aging in subjects with normal occlusion. The greater the degree of tooth wear at early adulthood, the greater the tooth wear at mature adulthood. Preventive care should be recommended during early adulthood in patients demonstrating erosive tooth wear in order to avoid worsening with aging.

Monitoring of erosive tooth wear: what to use and when to use it

Although we are increasingly recognising the need to assess patients for accelerated rates of tooth wear progression, it is often difficult to do so within a feasible diagnostic window. This paper aims to provide evidence-based timelines which a diagnosing clinician can expect to assess tooth wear progression in study models, clinical indices, clinical photographs and visually with intraoral scans. It also discusses new technologies emerging for the quantitative assessment of tooth wear, timelines for diagnosis, and caveats in the 3D scan registration and analysis process.

Understanding the Influence of Patient Factors on Accuracy and Decision-Making in a Diagnostic Accuracy Study with Multiple Raters-A Case Study from Dentistry

In diagnostic accuracy studies, the test of interest is typically applied only once in each patient. This paper illustrates some possibilities that arise when diagnoses are carried out by a sufficiently large number of multiple raters. In a dental study, sixty-one examiners were asked to diagnose 49 tooth areas with different grades of tissue loss (minor, moderate, and advanced) to decide whether dentine was exposed (positive status) or not (negative status). The true status was determined by histology (reference). For each tooth, the rate of correct decisions reflecting the difficulty to diagnose this tooth and the positive rate reflecting the perception of the tooth by the raters was computed. Meta-analytical techniques were used to assess the inter-tooth variation and the influence of tooth-specific factors on difficulty or perception, respectively. A huge variation in diagnostic difficulty and perception could be observed. Advanced tissue loss made diagnoses more difficult. The background colour and tissue loss were associated with perception and may hint to cues used by the raters. The use of multiple raters in a diagnostic accuracy study allows detailed investigations which make it possible to obtain further insights into the decision-making process of the raters.

Deterioration of anterior resin composite restorations in moderate to severe tooth wear patients: 3-year results

OBJECTIVES

Deterioration in anterior resin composite restorations placed in tooth wear patients was investigated after 36 months.

MATERIALS AND METHODS

Data collected prospectively for 47 participants of the Radboud Tooth Wear Project were used (41 ± 8 years, 90% male, n = 270 restorations). Restorations were individually evaluated using intraoral photographs and 3D scans to rate modified FDI scores and to record the presence of degradation features. Four groups with distinct combinations of composites and techniques were assessed, and multivariable logistic regression models were used to analyze the data (p < 0.05).

RESULTS

For all groups together, early degradation signs were present at 1 month: irregularities (41.5%) and ditching (7.4%) were observed at the surface and adhesive interfaces. The frequency of irregularities decreased in the 36-month evaluation (37%), but ditching (12.2%) and fractures (10.7%) were more common. The most frequent deterioration (based on photographs) was observed for staining (44%) and loss of luster (31%). In 3D scans, the most frequent were for wear (25%), marginal adaptation (24%), and the presence of irregularities (19%). Canines had 5.5 times more chances of deterioration by ditching than incisors (p < 0.001). The differences between composites and restorative techniques were minor.

CONCLUSIONS

A continuous degradation process of restorations placed in tooth wear patients was observed in anterior teeth restored with different composites, with a progression of the deterioration over 36 months.

CLINICAL RELEVANCE

When placing anterior resin composite restorations in tooth wear patients, it could be important to establish realistic expectations and the need for checkup appointments.

Prevalence and progression of erosive tooth wear among children and adolescents in a Swedish county, as diagnosed by general practitioners during routine dental practice

Objectives

To investigate the prevalence and four-year progression of erosive tooth wear (ETW) recorded in general dental practice, and to evaluate the usefulness of a simplified grading scale.

Methods

Four cohorts (aged 3, 7, 11 and 15 years at baseline; n = 735) were followed from 2008 to 2012 during their routine dental examinations. Grading of ETW was performed on permanent upper incisors and first molars, using the scales of Johansson et al. 1996 and Hasselkvist & Johansson 2010.

Results

Valid data were available for 641 individuals, 7-19-years of age, of whom 326 had data allowing analyses of progression. The prevalence of ETW increased with age, although at a lower level than in comparable studies. Progression was found in one-third of the subjects, with higher proportions and higher grades noted among the older cohorts. The simplified scale, that graded only four surfaces, resulted in just a few missed, mainly mild, cases of ETW.

Conclusions

Clinically significant signs of ETW and patterns of progression can be reliably detected if the erosion index used includes a few selected surfaces of permanent teeth as part of the routine dental examination. Early signs of ETW, however, seem to be more difficult to detect and evaluate.

Clinical significance

It is both possible and beneficial to introduce the diagnosing of ETW in routine dental examinations. To reduce the time involved in grading every patient, the simplified 4-surface application, seems to be a useful tool, but which is to be augmented with more extensive grading in individuals considered to be at risk.

Monitoring of Erosive Tooth Wear with Intraoral Scanners In vitro

Intraoral scanners (IOS) have been used to quantify tooth wear, but so far they have not been systematically validated for monitoring of tissue loss. The aim of this in vitro study was to investigate whether progression of tissue loss can be detected with an IOS and whether IOS values agree with those obtained with noncontacting profilometry (PRO) serving as a standard method. Model jaws were mounted in a phantom head positioned in a dental chair. Flattened areas were prepared on the non-load-bearing cusps of the first molars (model teeth; n = 16) in order to fix flat enamel samples with an experimental area and a reference area. After baseline PRO and IOS, the experimental enamel area was stepwise etched with 35% H3PO4 gel (4 × 30 s and 4 × 15 s). After each etching, PRO and IOS was performed and the vertical tissue loss between the reference and experimental areas was measured, each at the same 3 measurement points. Furthermore, cupped cusps were simulated by stepwise preparation of the load-bearing cusps of the model teeth with a spherical diamond bur, and the maximum vertical depth after each preparation step was measured only by IOS. Trios3 (3Shape, Denmark), Carestream CS3600 (Carestream, USA) and an optical profilometer (MicroProf, Fries, Germany) were used to measure the flat areas of the enamel samples, whereas only IOS were used to measure curved surfaces on the load-bearing cupped cusps of the model teeth. The IOS data were analyzed with an external software (GOM Inspect, Germany) and with the respective internal IOS software. PRO revealed a mean (±SD) tissue loss of 17.1 ± 4.7 µm after 30-s etching steps and 10.1 ± 5.1 µm after the 15-s etching steps. IOS and software types were able to detect the progression of tissue loss after each etching step (p ≤ 0.001 each); Bland-Altmann plots revealed good agreement with PRO regardless of the order of tissue loss, and no systematic difference was found. Increasing cupped lesion depths were detected by all IOS, with no significant differences between IOS and analysis methods. IOS were able to detect small amounts of tissue loss under simulated clinical conditions and seem to be a promising tool for monitoring even initial erosive tooth wear.

Quantifying increased rates of erosive tooth wear progression in the early permanent dentition

OBJECTIVES

To investigate if quantitative analysis of intraoral scans of study models can identify erosive tooth wear progression.

METHODS

Data were collected from a retrospective longitudinal study, using pre-and post-orthodontic treatment casts of 11-13 year olds, recorded at two consecutive appointments 29 months apart. Casts were digitised with intra-oral scanner TRIOS™ (3Shape, Copenhagen, Denmark) and first molar scan pairs used for analysis. Occlusal surfaces of each molar pair were visually assessed using the BEWE index as having no BEWE progression (n = 42) or BEWE progression (n = 54). Scan pairs were aligned and analysed for volume loss, maximum profile loss and mean profile loss in WearCompare (Leedsdigitaldentistry.com/wearcompare) using previously published protocols. Data were analysed in SPSS and not normal. Mann-Whitney U test with a Bonferroni correction assessed differences between progression groups. Receiver-operating-characteristic (ROC) curves were used to identify the sensitivity and specificity of quantified wear progression rates at determining visual wear progression.

RESULTS

Surfaces with visible progression demonstrated a median volume loss of -2.19 mm³ (IQR-3.65, -0.91) compared to a median volume loss of -0.37 mm³ (IQR -1.02, 0.16) in the no visible progression group (p < 0.001). Mean profile loss was -75.2 μm (IQR-93.9, -61.0) and 63.2 μm (IQR -82.5, -49.7) for the progression and no-progression groups respectively (p = 0.018). Volume loss of -1.22mm³ represented a 79 % sensitivity and 61 % specificity. The estimated area under the curve for volume loss was 0.80 (95 %CI 0.71-0.89, p < 0.001).

CONCLUSIONS

This is the first study to propose rates of high wear progression in adolescents. Limited sensitivity and specificity confirms that quantitative analysis is an adjunct tool to be used alongside history taking and clinical judgement.

CLINICAL SIGNIFICANCE

The rapid advancement of digital technologies may result in improved diagnosis in erosive tooth wear (ETW). Intra-oral scans and registration software are a promising adjunct for monitoring ETW progression in clinical practice.

Tooth surface loss: A review of literature

Objectives

Tooth surface loss (TSL) or tooth wear (TW) is an irreversible loss of hard tooth structure caused by factors other than those responsible for dental caries. TSL is observed clinically as attrition, abrasion, abfraction, and erosion. It may be associated with symptoms such as tooth hypersensitivity and function impairment, and may lead to change in the morphology of the affected tooth. However, it may also be asymptomatic, meaning the patient may not be aware of it. In this instance, the dentist is encouraged to make the patient aware of this issue.

The aim of this review is to provide an overview of the classification and management of TSL.

Material and methods

The PubMed (MEDLINE) search engine was used to gather the most recent information on TSL. The search was restricted to a five year period (1 September 2014–31 August 2019), and only English-language studies were included. A Boolean search of the PubMed dataset was implemented to combine a range of keywords: (Tooth surface loss OR tooth wear) AND (tooth attrition OR tooth Abrasion OR tooth erosion OR tooth abfraction OR non-carious cervical lesions) AND (humans). Studies were also obtained by manual searches and from Google Scholar.

Results

By this process, 560 articles and studies were obtained. More studies were also obtained by manual searches and from Google Scholar. The most relevant published studies were chosen and used in the current review. The selected articles are included in the reference list.

Conclusion

TSL is a clinical problem that dentists face on a daily basis. Therefore, a sound clinical approach by which TSL can be prevented and managed is essential. While this approach requires that dentists are knowledgeable about the issue, increasing public awareness of TSL is also vital.

The sensitivity of digital intraoral scanners at measuring early erosive wear

OBJECTIVES

To investigate the sensitivity of intraoral scanners to quantitatively detect early erosive tooth wear.

METHODS

Natural buccal enamel samples were mounted in acrylic and scanned at baseline with an intraoral scanner (3 M True Definition Scanner, 3 M, USA). Samples were then exposed to 0.3% citric acid pH 3.2 at intervals of 10 min up to a total of 120 min and scanned after each exposure resulting in analysis of 13 datapoints per sample. Each scan was aligned with the baseline and data points super-imposed using an iterative closest point (ICP) algorithm on the acrylic surfaces (Geomagic Control Software, 3Dsystems, Darmstadt, Germany). Wear was measured using maximum profile loss, average profile loss and volume change. Data were normally distributed and Pearson correlations between erosion time and wear measurements assessed.

RESULTS

After each 10-minute exposure until 120 min, maximum profile loss (μm) increased from 33.4 to 72.8 μm, average profile loss from 9.1 to 18.6 μm. Wear correlated with increasing acid exposure for both maximum profile loss wear (r = 0.877 p < 0.001) and average profile loss (r = 0.663 p = 0.019) respectively. Volume measurements were inconsistent at this level of wear.

CONCLUSIONS

Using scan data obtained from the intra oral scanners (IOS), increasing step height changes were observed with increasing exposures to acid. This study indicates there is potential of scans taken with an IOS to be used to detect early erosive tooth wear. However, precision was low suggesting limitations for minimal changes.

CLINICAL SIGNIFICANCE

Although sub-visual wear was detected by intra-oral scanners on natural enamel surfaces, the accuracy was not sufficient to reliably diagnose that wear had occurred and interpretation of measurements should be done with caution. However, these results may be promising for detecting wear at more advanced stages.