The worn dentition — pathognomonic patterns of abrasion and erosion

Novel 3-dimensional classification of cervical abrasion using CBCT: A comprehensive analysis

Introduction

Tooth cervical abrasion (CA) is a prevalent non-carious cervical lesion that poses challenges for accurate diagnosis from periapical radiographs due to difficulties in assessing the lesion's extent, associated bone loss, and pulpal involvement. The presence of overlying bone structures on the palatal side when lesions are located on the buccal side, or vice versa, further complicates radiographic interpretation. So it is important to define the lesions in all three dimensions.

Objective

To provide a three-dimensional descriptive classification for cervical abrasion lesions using Cone Beam Computed Tomography (CBCT).

Method

A total of 50 patients with cervical abrasion were selected for the study. From these patients, teeth (n = 10) from each of the four different quadrants were chosen. A CBCT scan with a 6 × 6 cm field of view (FOV) was performed, and the DICOM files of the cervical lesions were transferred to 3-D imaging software. The CBCT images of the cervical abrasion lesions were assessed at the level of the deepest point of the lesion along the long axis of the tooth in both axial and sagittal planes. The height (A), buccolingual dimension (B), circumferential spread (C), and remaining dentine thickness (D) were evaluated and classified using new scoring criteria for each dimension. The reliability and reproducibility of the classification were assessed to ensure its clinical applicability.

Conclusion

CBCT can be utilized to classify tooth cervical abrasion in endodontics, enhancing diagnosis, analysis, and treatment outcomes. This three-dimensional view facilitates easier communication among clinicians, allows for tailored treatment approaches, and opens new avenues for research.

Laser debonding of ultrathin occlusal veneers fabricated from different CAD/CAM ceramic materials

BACKGROUND

Erbium lasers safely offer the possibility of reuse for debonded restorations. Since these lasers have a high affinity for water molecules, they are absorbed by resin cement causing explosive ablation of the cement and thus, the restoration debonds. The efficiency of this process depends on many factors, including the ceramic type, its chemical composition and thickness. Therefore, this study was designed to test the time taken to debond ultrathin occlusal veneers made of three types of milled ceramic materials and evaluate the integrity of these restorations after debonding.

METHODS

Three ceramic types were evaluated in this study: lithium disilicate (IPS Emax CAD), highly condensed lithium disilicate (GC initial®LiSi), and translucent zirconia (Katana zirconia STML). Each group consisted of 8 occlusal veneers of 0.5 mm thickness. The samples were cemented to the occlusal surfaces of the upper molar teeth. An Er; Cr: YSGG laser was applied to the occlusal veneers using the scanning method, and time until debonding was calculated. The debonded samples were then inspected under a stereomicroscope for possible damage. Numerical data are presented as the mean with 95% confidence interval (CI), standard deviation (SD), minimum (min.) and maximum (max.) values. Normality and variance homogeneity assumptions were confirmed using Shapiro-Wilk's and Levene's tests, respectively. Data were normally distributed and were analyzed using one-way ANOVA followed by Tukey's post hoc test. The significance level was set at p < 0.05 for all tests. Statistical analysis was performed with R statistical analysis software version 4.3.2 for Windows (R Core Team (2023). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL https://www.R-project.org/).

RESULTS

There was no significant difference in debonding time between the different materials (p = 0.995). The longest debonding time was found for Katana STML (87.52 ± 20.45) (seconds), followed by Emax (86.94 ± 20.63) (seconds), while the lowest value was found for LiSi initial (86.14 ± 25.16) (seconds). In terms of damage to the debonded veneers, The Emax and zirconia samples showed no damage. However, 40% of the LiSi samples fractured during debonding, and 20% exhibited cracks. Only 40% of the LiSi samples were sound after debonding.

CONCLUSION

Er; Cr: YSGG laser can be used efficiently to remove ceramic occlusal veneers. However, its effect on LiSi restorations needs further research.

The effect of location/site on polished human enamel after mechanical and chemical wear

OBJECTIVE

To compare profilometry and microhardness of polished occlusal and buccal human enamel following a mechanical and chemical wear regime.

METHODS

Enamel from polished human molars were sectioned into buccal and occlusal surfaces and randomly allocated into two groups (n = 10) and then exposed to 0.3 % citric acid at pH 2.7 for 10, 20, 40 and 60 mins each followed by abrasion with non-fluoridated toothpaste for 240 strokes in a reciprocating brushing machine. A white light profilometer with a spot size of 12 um measured mean step-height following each cycle. Microhardness indentations were conducted following the final cycled 60 mins erosion/abrasion using 0.01, 0.02, 0.1, 0.5 and 2.5 kgf indentation load. Statistical disparity were evaluated using a two-way ANOVA and post-hoc Sidak's multiple comparisons tests at α = 0.05.

RESULTS

After erosion/abrasion, the mean (SD) step-heights on occlusal and buccal surfaces were not significantly different until 60 mins, when occlusal surfaces exhibited greater step-heights, 32.9 µm (2.8) and 31.1 µm (1.8) and p = 0.02, respectively. Buccal and occlusal microhardness was statistically lower following erosion/abrasion at loads of 0.01 kgf (p = 0.0005) and 0.02 kgf (p = 0.0006) but no significant differences were observed in the microhardness between the surfaces at any loads.

CONCLUSION

The occlusal and buccal surfaces were not statistically different for microhardness or step height suggesting the susceptibility to wear is not related to the anatomy and structure of the tooth and is more likely related to other factors such as the environment.

CLINICAL SIGNIFICANCE

The study emphasizes that a notable difference in wear between occlusal and buccal enamel surfaces emerges only after prolonged exposure to simultaneous chemical and mechanical stress. This finding necessitates a preventive dental approach that accounts for both the duration of exposure and environmental factors.

Clinical and Biomechanical Performance of Occlusal Veneers: A Scoping Review

AIM

This manuscript aims to evaluate, through a scoping review, current knowledge of the biomechanical behavior, materials, preparations, and limitations of occlusal veneers.

BACKGROUND

Occlusal veneers are a minimally invasive alternative for the additive restoration of posterior teeth with significant loss of the occlusal structure. This type of restoration has been emerged in recent years as an alternative to invasive treatment, which in the same way seeks to restore the structure of the posterior teeth. All this is because in recent years restorative dentistry has focused a large part of its objectives on conservative therapies.

REVIEW RESULTS

Five electronic databases-PubMed, Cochrane, LILACS, EMBASE, and Google Scholar-were searched. Title and abstracts were independently screened by three reviewers, followed by a full-text review. A total of 42 articles met our inclusion criteria; most of these studies were in vitro (n = 35) and other studies were clinical studies (n = 7). These in vitro studies included 21 studies that analyzed the type of preparation and 6 studies that evaluated the limitations of occlusal veneers.

CONCLUSION

Thicknesses between 0.7 and 1.0 mm are recommended for ceramic materials; in addition, thicknesses less than 0.7 mm are recommended to use polymeric materials. The materials used for this type of restoration are plastic- and ceramic-based materials, whose load resistance values were found to exceed 2000 N in most studies. It is recommended to carry out a minimally invasive preparation or not to carry out a dental preparation, as long as there is a peripheral enamel to make an external bevel that redirects the eccentric forces to the axis of the tooth.

CLINICAL SIGNIFICANCE

Restorative dentistry has moved toward conservative treatments with the least amount of dental tissue being removed. Occlusal veneers appear to be a conservative option in the reconstruction of tooth tissues lost due to tooth wear and in cases where it is necessary to restore or increase the vertical dimension.

Clinical presentation of two phenotypes of tooth wear patients

OBJECTIVE

To assess the clinical presentation of wear lesions in two phenotypes of tooth wear (TW) patients based on distribution and morphological features of wear.

MATERIALS AND METHODS

103 patients (mean age = 43.1 years) were divided into two groups based on cluster analysis; cluster A (61 patients) and cluster B (42 patients). The distribution of wear lesions, scores of presence or absence of 10 defined morphological TW criteria and number of teeth fulfilling each criteria were compared between groups. Intra- and inter-examiner reliability of the 10 TW criteria was determined by Cohen's kappa and intraclass correlation coefficient.

RESULTS

While cluster A had more wear in maxillary anterior teeth and mandibular molars compared with the same opposing tooth groups (p < 0.001, p < 0.007 respectively), there were no differences for cluster B. Cluster A was characterized by higher prevalence of 4 chemical morphological criteria and the highest number of teeth affected by one chemical criteria, whereas cluster B had a higher prevalence of one mechanical criteria and higher number of teeth affected by an additional mechanical criteria. Both intra- and inter-examiner values for the defined TW criteria were fair to excellent.

CONCLUSION

The results may indicate a more chemical background for TW in cluster A and mechanical background in cluster B. Furthermore, clinicians may use certain clinical features of TW to distinguish between individuals who belong to a specific TW cluster with a presumed chemical or mechanical etiology. These preliminary findings need to be confirmed in future studies.

Cup-Shaped Tooth Wear Defects: More than Erosive Challenges?

BACKGROUND/AIM

The underlying mechanism of the development of cups and grooves on occlusal tooth surfaces is still unclear. The aim of this study was to evaluate factors contributing to in vitro cup formation, in order to elucidate the clinical process.

METHODS

A total of 48 extracted human molar teeth were exposed to acidic aqueous solutions at pH of 4.8 and 5.5 in constant motion, in combination with different loading conditions: no load (0N group, control), 30 N (30N group) or 50 N (50N group) (n = 8 per group). Before and after 3 months of exposure (1,422,000 loading cycles), the samples were scanned using a non-contact profilometer. Pre- and post-exposure scans were subtracted and height loss and volume tissue loss were calculated. Representative samples with wear and cupping lesions were imaged using scanning electron microscopy, light microscopy and micro-computed tomography.

RESULTS

Average height and volume tissue loss at pH 5.5 was 54 µm and 3.4 mm3 (0N), 52 µm and 3.4 mm3 (30N) and 58 µm and 3.7 mm3 (50N), respectively, with no statistically significant differences. Average height and volume loss at pH 4.8 were 135 µm and 8.7 mm3 (0N), 172 µm and 12.6 mm3 (30N) and 266 µm and 17.8 mm3 (50N), respectively, with a statistically significant difference between 0N and 50N (p < 0.002). Cup-shaped lesions had formed only at pH of 4.8, in the 30N and 50N groups.

CONCLUSION

The study showed that a cup can arise fully in enamel and that mechanical loading in addition to erosive challenges are required.

Mimicking and Measuring Occlusal Erosive Tooth Wear with the "Rub&Roll" and Non-contact Profilometry

Chewing, drinking, and occasional tooth grinding will result in physiological tooth wear during a lifetime. Extreme challenges, such as bruxism or habitual chewing on foreign objects, may lead to excessive wear. Recently, the role of erosion in accelerating mechanical tooth wear has been recognized, but the interplay between chemical and mechanical wear processes has not been extensively studied. Our laboratory recently introduced a novel oral wear simulation device, the Rub&Roll, that enables the user to perform wear and loading studies separately or simultaneously in an erosive and/or abrasive environment. This manuscript describes an application of the device: the combined mechanical and erosive loading of extracted human (pre)molars in a simulated chewing movement, with a controlled application of force, velocity, fluid, and time, and the application of non-contact profilometry in visualizing and measuring the resulting wear pattern. The occlusal morphology that was created in the experiment with the highest loading level is very similar to the clinical presentation of erosive wear.

Dental erosion in patients seeking treatment for gastrointestinal complaints: a case series

INTRODUCTION

Eating disorders which embrace anorexia nervosa, bulimia nervosa, and eating disorders not otherwise specified can be life-threatening due to general medical complications; however, the diagnosis of eating disorder is often delayed due to a low suspicion index. Gastroenterologists are health care providers who may come into contact with patients with undiagnosed eating disorders; it has been previously demonstrated that patients with eating disorders frequently have a significant association with functional dyspepsia. Signs of dental erosion have been described in patients with eating disorders; hence, they may help to identify eating disorders in patients who present with functional dyspepsia and deny having an eating disorder.

CASE PRESENTATION

In this report we describe three cases (a 25-year-old white woman, a 24-year-old white woman, and a 40-year-old white man) with undiagnosed eating disorders, in which a more comprehensive approach, such as the recognition of dental erosion joined with a careful gastrointestinal investigation, was performed to reach a final diagnosis of an eating disorder.

CONCLUSIONS

The screening for dental erosion in patients seeking or receiving medical treatment for dyspeptic symptoms in a gastrointestinal out-patient clinic could be an aid for gastroenterologists to recognize the presence of an underlying eating disorder. A close collaboration with dentists, in addition to psychiatrists, could provide a more favorable treatment outcome.

A Single Visit Direct Technique to Provisionally Restore Occlusion for a Full-Mouth Rehabilitation: A Clinical Report

Attrition of the dentition can negatively affect esthetics and function. When reconstructing patients with attrition who require restoration at increased occlusal vertical dimension (OVD), it is necessary to first evaluate the OVD using a removable interim prosthesis to ensure that the patient will tolerate the new position. The transition to fixed interim prostheses has to be carefully planned to achieve the desired OVD. One approach is to prepare all teeth in a single day and place full-arch interim prostheses; however, this can be tiring for the patient and prosthodontist. An alternative approach is to prepare one arch and place interim prostheses, while using composite resin in the opposing arch to maintain the newly established OVD. A diagnostic wax-up at the proposed OVD is completed and duplicated in stone. A vacuform matrix is loaded with composite resin and applied to the unprepared etched teeth of the opposing arch to restore form and occlusion until full contour interim prostheses are placed at a later visit.

Implant-Supported Prosthetic Rehabilitation of a Patient with Localized Severe Attrition: A Clinical Report

Patients usually adapt to their existing occlusal vertical dimension (OVD). It is essential to resolve each of the problems associated with decreased vertical dimension as a result of attrition. This report describes the multidisciplinary dental treatment of a 40-year-old male patient who had severe tooth wear, resulting in reduced vertical dimension. After clinical evaluations, extraoral examination showed a reduction of the lower facial height, drooping, and overclosed commissures. Ten dental implants were placed into the maxillary and mandibular alveolar processes. During the osseointegration period, an interim removable partial denture was made at increased OVD to use in the first stage of rehabilitation. It was used for 3 months as a guide for preparing the definitive restorations. The patient's adaptation to the increased OVD was evaluated. During this period, he was asymptomatic. Following the evaluation period, the provisional fixed restoration was used for 3 months. Then, full-mouth definitive prostheses supported by a combination of implants and teeth were fabricated to upper and lower jaws. Osseointegration of the implants, peri-implant mucosa health, prosthesis function, and esthetics were assessed after 1 week and 1, 3, and 6 months. After 3 years of follow-up, no functional or esthetic difficulties with the implants and restorations were noted.

Abfraction: A review

Abfraction (AF) is the pathological loss of tooth substance caused by biomechanical loading forces that result in flexure and failure of enamel and dentin at a location away from the loading. The theory of AF is based primarily on engineering analyses that demonstrate theoretical stress concentration at the cervical areas of the teeth. However, the theory is not yet proven and there are explanations against it. AF lesions present primarily at the cervical region of the dentition and are typically wedge-shaped, with sharp internal and external line angles. Diagnosis of AF plays a very important role in the management of patients. The aim of the present narrative review is to comprehensively discuss the historical, etiopathogenetic, clinical, and diagnostic and treatment aspects of AF.

In vitro reproduction of incisal/occlusal cupping/cratering

STATEMENT OF PROBLEM

Occlusal cupping/cratering (depressed dentin surrounded by elevated rims of enamel) has been postulated to be the result of abrasion, bruxism, attrition, acid erosion, stress corrosion, or a combination of these. The primary etiology or the multifactorial sequence of occlusal cupping/cratering remains scientifically unsubstantiated.

PURPOSE

The purpose of this study was to reproduce occlusal/incisal cupping/cratering in vitro. This study was designed to create cupping/cratering on the occlusal surfaces of extracted human teeth rather than to quantify the amount of lost tooth structure caused by abrasion.

MATERIAL AND METHODS

One name-brand toothbrush was tested with 2 different dentifrices (of different abrasive potentials [low and high]) and water only (nonabrasive) on extracted human teeth. Six specimens of 4 teeth each (24 teeth) were subjected to horizontal brushing in a 1:1 toothpaste/water slurry and water only.

RESULTS

The control group, brushed with water only, demonstrated no visible loss of tooth structure. Each of the specimens brushed with toothpaste, regardless of the degree of abrasivity, demonstrated visible wear of the dentin, resulting in occlusal/incisal cupping/cratering.

CONCLUSIONS

Pronounced cupping/cratering was caused by horizontal brushing with commercial toothpastes. Brushing in water demonstrated no visual loss of occlusal tooth structure. (J Prosthet Dent 2013;109:384-391).

Immediate loading of dental implants in the esthetic region using computer-guided implant treatment software and stereolithographic models for a patient with eating disorders

This manuscript describes the reconstruction of a maxillary anterior segment using immediate implant placement and immediate implant loading techniques, aided by computer-guided implant treatment software and stereolithographic models and surgical templates, in a patient with a history of eating disorder. Her medical and dental histories did not make her a candidate for the use of conventional 2-stage implant surgery and restorative procedures along with an interim removable prosthesis.

A classification of the mechanisms producing pathological tissue changes

The objectives are to present a classification of mechanisms which can produce pathological changes in body tissues and fluids, as well as to clarify and define the term biocorrosion, which has had a singular use in engineering. Considering the emerging field of biomedical engineering, it is essential to use precise definitions in the lexicons of engineering, bioengineering and related sciences such as medicine, dentistry and veterinary medicine. The mechanisms of stress, friction and biocorrosion and their pathological effects on tissues are described. Biocorrosion refers to the chemical, biochemical and electrochemical changes by degradation or induced growth of living body tissues and fluids. Various agents which can affect living tissues causing biocorrosion are enumerated which support the necessity and justify the use of this encompassing and more precise definition of biocorrosion. A distinction is made between the mechanisms of corrosion and biocorrosion.

The evolutionary paradox of tooth wear: simply destruction or inevitable adaptation?

Over the last century, humans from industrialized societies have witnessed a radical increase in some dental diseases. A severe problem concerns the loss of dental materials (enamel and dentine) at the buccal cervical region of the tooth. This “modern-day” pathology, called non-carious cervical lesions (NCCLs), is ubiquitous and worldwide spread, but is very sporadic in modern humans from pre-industrialized societies. Scholars believe that several factors are involved, but the real dynamics behind this pathology are far from being understood. Here we use an engineering approach, finite element analysis (FEA), to suggest that the lack of dental wear, characteristic of industrialized societies, might be a major factor leading to NCCLs. Occlusal loads were applied to high resolution finite element models of lower second premolars (P₂) to demonstrate that slightly worn P₂s envisage high tensile stresses in the buccal cervical region, but when worn down artificially in the laboratory the pattern of stress distribution changes and the tensile stresses decrease, matching the results obtained in naturally worn P₂s. In the modern industrialized world, individuals at advanced ages show very moderate dental wear when compared to past societies, and teeth are exposed to high tensile stresses at the buccal cervical region for decades longer. This is the most likely mechanism explaining enamel loss in the cervical region, and may favor the activity of other disruptive processes such as biocorrosion. Because of the lack of dental abrasion, our masticatory apparatus faces new challenges that can only be understood in an evolutionary perspective.

Neuromuscular dentistry: Occlusal diseases and posture

Neuromuscular dentistry has been a controversial topic in the field of dentistry and still remains debatable. The issue of good occlusion and sound health has been repeatedly discussed. Sometimes we get complains of sensitive teeth and sometimes of tired facial muscles on getting up in the morning. Owing to the intimate relation of masticatory apparatus with the cranium and cervico-scapular muscular system, the disorders in any system, draw attention from concerned clinicians involved in management, to develop an integrated treatment protocol for the suffering patients. There may be patients reporting to the dental clinics after an occlusal restoration or extraction, having pain in or around the temporomandibular joint, headache or neck pain. Although their esthetic demands must not be undermined during the course of treatment plan, whenever dental treatment of any sort is planned, occlusion/bite should be given prime importance. Very few dentist are able to diagnose the occlusal disease and of those who diagnose many people resort to aggressive treatment modalities. This paper aims to report the signs of occlusal disease, and discuss their association with TMDs and posture.

Tooth wear and wear investigations in dentistry

Tooth wear has been recognised as a major problem in dentistry. Epidemiological studies have reported an increasing prevalence of tooth wear and general dental practitioners see a greater number of patients seeking treatment with worn dentition. Although the dental literature contains numerous publications related to management and rehabilitation of tooth wear of varying aetiologies, our understanding of the aetiology and pathogenesis of tooth wear is still limited. The wear behaviour of dental biomaterials has also been extensively researched to improve our understanding of the underlying mechanisms and for the development of restorative materials with good wear resistance. The complex nature of tooth wear indicates challenges for conducting in vitro and in vivo wear investigations and a clear correlation between in vitro and in vivo data has not been established. The objective was to critically review the peer reviewed English-language literature pertaining to prevalence and aetiology of tooth wear and wear investigations in dentistry identified through a Medline search engine combined with hand-searching of the relevant literature, covering the period between 1960 and 2011.

Safety of oscillating-rotating powered brushes compared to manual toothbrushes: a systematic review

BACKGROUND

Oscillating-rotating power toothbrushes have been proven clinically efficacious. To our knowledge, a comprehensive review of all clinical and laboratory investigations solely comparing the safety of these toothbrushes to the standard of care (i.e., manual toothbrushes) has not been published. The aim of this systematic review is to examine the literature concerning the relative soft and/or hard tissue safety outcomes with the use of oscillating-rotating toothbrushes compared to manual toothbrushes.

METHODS

With the use of electronic databases of the National Library of Medicine (PubMed-MEDLINE), the Cochrane Central Register of Controlled Trials (Cochrane-CENTRAL), and the Excerpta Medical Database (EMBASE), a search of in vivo and in vitro trials through May 2010 was conducted to identify appropriate studies that evaluated the effects of an oscillating-rotating power toothbrush compared to a manual toothbrush with respect to soft and/or hard tissue safety. Eligible trials incorporated a safety evaluation as a primary or secondary outcome parameter (i.e., gingival recession, observed/reported adverse events, and hard tissue effects) or used a surrogate parameter (i.e., stained gingival abrasion and brushing force) to assess safety. Data extraction for the primary- and surrogate-measure safety studies, which included mean values and SDs when available, and a meta-analysis of the gingival recession data were performed.

RESULTS

Independent screening of the titles and abstracts of 697 PubMed-MEDLINE, 436 Cochrane-CENTRAL, and 664 EMBASE papers resulted in 35 publications that met the eligibility criteria. The mean change in gingival recession was not significantly different among toothbrush groups in the two selected trials with safety as a primary outcome (weighted mean difference: 0.03). A meta-analysis of the five trials that evaluated safety with a surrogate parameter was not possible; however, there were no significant between-group differences at the study end in any trial. A descriptive analysis of the 24 selected studies assessing safety as a secondary outcome revealed few brushing-related adverse events. The heterogeneity in objectives and methodology of the four in vitro trials that met the eligibility criteria precluded generalization of the results.

CONCLUSION

A large body of published research in the preceding 2 decades has consistently shown oscillating-rotating toothbrushes to be safe compared to manual toothbrushes, demonstrating that these power toothbrushes do not pose a clinically relevant concern to hard or soft tissues.

The Significance of Sub-Threshold Symptoms of Anxiety in the Aetiology of Bruxism

Bruxism is the oral parafunctional habit of clenching and grinding the teeth. It occurs mainly unconsciously, diurnally and/or nocturnally. It is considered an important contributory factor in the aetiology of myofascial pain and temporomandibular joint disorders and derangements. The aetiology of bruxism is considered to be multifactorial, involving both physiological and psychological factors. The aim of the study was to examine the relationship between the sub-threshold symptoms of anxiety and bruxism, using a spectrum model. Firstly, levels of anxiety were determined using the Spielberger State Trait Anxiety Inventory (STAI) and the Kessler-10 (K-10). Secondly, a tooth-wear score was determined by means of a clinical examination and dental casts. Thirdly, bruxism was rated on an ordinal scale according to specified criteria. A dualistic trend in the relationship between sub-threshold symptoms of anxiety and bruxism was observed in the results. In approximately half of the subjects with higher than average anxiety scores, bruxistic behaviour was found. This indicates the possibility of two groups with separate relationships. The dentist could play a role in recognizing that a patient may be experiencing anxiety, expressed through bruxism behaviour, and refer the patient for therapy or counselling. An understanding of the psychological factors involved in the aetiology of bruxism could foster a more holistic approach to the treatment of patients with signs of bruxism.

In vitro reproduction of noncarious cervical lesions

STATEMENT OF PROBLEM

A review of the dental literature indicates that noncarious cervical lesions (NCCLs) are formed by erosion, abrasion, and/or abfraction of tooth structure, but their etiology remains scientifically unsubstantiated.

PURPOSE

The purpose of this study was to reproduce noncarious cervical lesions in vitro. This study was not designed to statistically quantify the amount of lost tooth structure via abrasion, but rather to attempt to create NCCLs in the various shapes and sizes that are clinically observed.

MATERIAL AND METHODS

Three pairs of toothbrush types (generic and name-brand) with soft, medium, or firm bristles were tested with 3 different toothpastes of varying abrasive potentials (low, medium, and high) or with water only, on mounted human teeth with and without simulated gingival tissues (6 toothbrushes x 4 brushing solutions (L, M, H, dentifrices, or water only) x 2 gingival mask conditions = 48 test/control groups of 4 teeth each = 192).

RESULTS

The control sets, brushed in water only, demonstrated no visible loss of tooth structure. Each set brushed with toothpaste, regardless of the degree of abrasiveness or toothbrush bristle firmness, demonstrated visible wear at the level of the CEJ.

CONCLUSIONS

Significant noncarious cervical lesions were created via horizontal brushing with common commercial toothpaste, while brushing with water only did not create these cervical lesions.

[Not Available]

Severe tooth wear is discussed from the perspective of appreciating the aetiologic background of the problem. A multifactorial basis is acknowledged for the extensively worn dentition and efforts to eliminate or minimize these underlying factors are important. The management of a case of severe incisal and occlusal wear can adopt different approaches. The author proposes the rationale and advantages for involving orthodontic preparation as part of the occlusal rehabilitation.