Developing diagnostic criteria for tooth wear, a preliminary beta version based on expert opinion, and a narrative literature review.

BACKGROUND: Tooth wear is a multifactorial condition, leading to the irreversible loss of dental hard tissues. The availability of an unambiguous, universally applicable assessment protocol remains lacking. OBJECTIVES: The goal of the authors is to develop a set of diagnostic criteria for the assessment of tooth wear (DC-TW). A two-step approach will be used to achieve this objective: (1) to develop a preliminary beta version of the DC-TW, based on the authors' clinical experience and their shared expertise and supported by a narrative review of the existing literature, and (2) to develop the final DC-TW, with input from a larger group of experts using an international Delphi process. This paper relates to the first step. METHODS: The authors outlined the components that should be incorporated into the DC-TW. The literature search was performed to investigate if their concept was in line with the available literature. The search was conducted to identify eligible publications from inception to July 11, 2022. Two authors independently screened all publications, and differences in judgements were resolved through a consensus procedure. RESULTS: The search yielded 5362 publications, resulting in the final inclusion of 383. These publications were divided into four main topics: (1) nomenclature/taxonomies; (2) self-report tools; (3) clinical assessment tools; and (4) clinical decision-making. CONCLUSIONS: The information from the publications was used and fused with the clinical experience and shared expertise of the authors to contribute to the development of a preliminary beta version of the DC-TW.

Randomised controlled trial on testing an increased vertical dimension of occlusion prior to restorative treatment of tooth wear.

BACKGROUND: Evaluation of a new vertical dimension of occlusion (VDO) in complex restorative treatments is considered a necessary step prior to placement of restorations. OBJECTIVES: This randomised controlled trial (RCT) aimed to assess the effects of using an evaluation of a VDO increase before restorative treatment in patients with moderate-to-severe tooth wear, on OHRQoL, freeway space (FWS) and interventions to restorations. METHODS: Forty-two patients with tooth wear were included and randomly allocated to either a test phase with a Removable Appliance (RA) or no test phase. Restorative treatment consisted of restoration of all teeth using composite restorations in an increased VDO. OHIP-score, freeway space (FWS) and clinical acceptability of restorations were assessed at baseline and at recall appointments (1 month and 1 year). Intervention to restoration was scored in case of material chipping or when the abutment tooth had increased sensitivity that could be linked to occlusal overloading. ANCOVA analyses, Univariate Cox regression, t-tests and descriptive analyses were performed (p < .05). RESULTS: Clinical follow-up after 1 year was completed for 41 patients. No significant effect of testing the VDO with a RA could be found on the OHIP-score (p = .14). Reduction of FWS in the RA group, compared to the control group, was significantly lower at 1 year (p = .01, 95% CI -1.09 to -0.15). No effect on early interventions to restorations was found (p = .94). CONCLUSION: This RCT showed that a removable appliance is not indicated to functionally test the increased VDO prior to restorative treatment in patients with tooth wear.

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.

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 (κW ) 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.

Speech changes in patients with a full rehabilitation for severe tooth wear, a first evaluation study.

OBJECTIVE: The aim of this study was to evaluate changes in speech characteristics and self-perceived quality of speech in tooth wear patients, after occlusal rehabilitation. MATERIALS AND METHODS: Patients with tooth wear were included in this study after informed consent. The amount of tooth wear was scored with Tooth Wear Evaluation System (TWES). To assess the perspective of the patient, the Dutch Speech Handicap Index was used (SHI). Acoustic analysis was performed to evaluate changes with the use of voice recordings. These were made before treatment, T0; directly after treatment, T1; 1 month after treatment, T2. With the use of PRAAT software, the spectral characteristic centre of gravity (COG) was evaluated for the sounds /s/, /f/, /v/, /d/, /t/, /m/. RESULTS: Recordings of 17 patients (14 men, 3 women, mean age 41.2 ± 10.4 years) were included. SHI scores did not change significantly between T0 and T2 (p = 0.054). A multiple regression model showed that for all sounds the intercept was negative, but statistically significant only for /s/ and /f/ between T0 and T1. The effect of the initial change (between T0 and T1) on the change between T1 and T2 was clearly negative for all sounds (p < 0.001), showing a rebound effect ranging between 29 and 68% of the initial change. CONCLUSION: Tooth wear patients perceive improvement in speech function after treatment. CLINICAL SIGNIFICANCE: Clinicians may explain to patients that speech is likely to alter for a short period due to treatment but that there will be a good adaption to the new situation.

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.

The influence of management of tooth wear on oral health-related quality of life.

OBJECTIVE: The purpose of this study was to identify the level of oral health-related quality of life and orofacial appearance in patients with moderate to severe tooth wear. Patients with and without a request for restorative treatment were included. METHODS: One hundred twenty-four patients (98 men, 26 women, mean age: 40.5 ± 8.8 years) with moderate to severe tooth wear were included. Patients without a request for help received a non-restorative treatment of counseling and monitoring. Patients with a request for restorative treatment were treated with a full rehabilitation using composite resin restorations. Oral Health Impact Profile (OHIP-NL) and Orofacial Esthetic Scale (OES-NL) questionnaires were filled in at baseline and after 1 year. RESULTS: Counseling and monitoring group: baseline OHIP-NL score was 0.4 ± 0.3, baseline summary score of OES-NL was 48 ± 7.0, and baseline impression score was 7.1 ± 1.2. Scores had not changed significantly after 1 year (p = 1.00 after Bonferroni correction).Restoration group: baseline OHIP-NL score was 0.8 ± 0.6, baseline summary score of OES-NL was 38 ± 10, and baseline impression score was 5.9 ± 1.5. Scores had improved significantly after 1 year (p < 0.001 after Bonferroni correction). CONCLUSIONS: Counseling and monitoring did not result in a significant deterioration and restorative treatment resulted in a significant improvement of oral health-related quality of life (OHRQoL) and orofacial appearance in this patient group. CLINICAL SIGNIFICANCE: In patients with moderate to severe tooth wear, without functional and esthetical problems, counseling and monitoring may be an appropriate treatment option. Restorative treatment in patients with a need for treatment results in an improved OHRQoL. OHIP and OES questionnaires may be used to monitor changes in clinically relevant symptoms.

Combined orthodontic, surgical, and restorative approach to treat a complicated crown-root fracture in a maxillary central incisor.

This case report shows the treatment of a severe traumatic tooth injury. For the maxillary right central incisor, the trauma was considered a complicated crown-root fracture. The level of the fracture line, the length of the remaining root segment, and the presence and condition of the tooth fragment determined the type of therapy. Traumatized teeth with fractures below the alveolar crest are often considered hopeless. As this report shows, the treatment of a complicated crown-root fracture in the esthetic region can be challenging. Orthodontic extrusion and crown-length surgery were performed to bring the fracture line above the alveolar bone crest. A multidisciplinary approach was required for complete rehabilitation of the traumatized maxillary incisor. Suggestions are made to improve treatment planning of complicated crown-root fractures.

3D Facial Effects of a Simulated Dental Build-up.

OBJECTIVE: The purpose of this study was to evaluate the 3D-stereophotogrammetry technique to detect differences in facial appearance after a simulated rehabilitation. MATERIALS AND METHODS: Eleven volunteers without tooth wear participated. A 3D-stereophotograph was taken in five different situations: resting position, teeth in occlusion, and teeth in occlusion with a 1 mm-, 3 mm- or 5 mm resin block between the first molars. Cephalometric measurements were performed on the 3D-stereophotographs using the software program Maxilim® (Medicim NV Mechelen, Belgium). Four anatomical parameters were analyzed: (1) Subnasale-Gnathion, (2) Subnasale-Stomion, (3) Stomion-Gnathion, and (4) Masseter right-Masseter left. A paired Student's T-test was applied to detect significant differences (p < 0.05). RESULTS: Statistically significant changes in facial appearance of the lower facial height were detected in all measured positions, teeth in occlusion, 1 mm-, 3 mm-, and 5 mm block (p < 0.05). For the main distance (Subnasale-Gnathion) the mean measured differences were, respectively, 3.2 mm; 5.2 mm; and 6.7 mm. CONCLUSIONS: With 3D-stereophotograph imaging technology, it was possible to detect changes in facial appearance after an artificial increase of vertical dimension of occlusion. This finding implies that reconstruction of loss of tooth substance may cause a visible change in facial appearance of the patient. CLINICAL SIGNIFICANCE: This study reveals a new 3D imaging technique that may be used for a better and more comprehensive treatment planning in patients with severe tooth wear. (J Esthet Restor Dent 28:397-404, 2016).

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.

The longevity of tooth-coloUred materials used for restoration of tooth wear: an evidence-based approach.

Patients with tooth wear are commonly encountered in general dental practice. When indicated, restorative rehabilitation is often accompanied by a request from the patient for an aesthetic, tooth-coloured outcome. This article seeks to provide an evidence-based approach, focussing on the longevity of the materials which can be used for the restorative treatment of tooth wear, as well as their modes of failure and observed performance.

Association between salivary characteristics and tooth wear: A systematic review and meta-analysis.

OBJECTIVE: Literature was systematically reviewed to identify salivary characteristics and their association with tooth wear. DATA: A protocol was developed a priori (PROSPERO CRD42022338590). Established systematic review methods were used for screening, data extraction, and synthesis. Risk of bias and the certainty of evidence were assessed using the JBI tools and GRADE, respectively. Direct and indirect association between tooth wear and salivary components and characteristics were assessed. SOURCES: MEDLINE, Embase, SCOPUS, Web of Science, CINAHL, and additional sources were searched. STUDY SELECTION: Studies reporting salivary characteristics in patients with tooth wear or models thereof were included. Animal and in-vitro studies and case reports were excluded. RESULTS: One-hundred eleven studies were included. Qualitative analyses showed a negative association between tooth wear and salivary pH and flow rate in many studies. The higher the study size the higher the chances that an association with pH and flow rate was found. Xerostomia, buffer capacity and salivary consistency/viscosity had also some degree of association with tooth wear in fewer studies. Associations with the 39 salivary components were scarcer. Random effects meta-analyses (7 studies) showed that pH levels in stimulated whole saliva were lower in patient with tooth wear compared to controls (-0.07 [-0.10 to -0.04]). However, there was not enough evidence to establish a quantitative association with flow rate. The general risk of bias was unclear and the certainty of evidence was low or very low. A large diversity of methodologies limited the inclusion of all studies in quantitative synthesis. CONCLUSION: From all potential risk factors, stimulated whole saliva pH showed a negative association, both quantitatively and qualitatively with tooth wear, indicating potential usefulness of pH monitoring in these patients. Moreover, associations between flow rate and tooth wear were observed qualitatively. However, in both cases the risk of bias was mostly unclear, and the certainty of evidence was low. No causal associations could be observed. CLINICAL SIGNIFICANCE: Tooth wear is a prevalent condition that may lead to functional or esthetic impairments and pain. Knowing the potential risk factors like salivary pH or flow rate and their dynamics could be relevant during tooth wear monitoring and to intervene accordingly, especially in conditions like gastroesophageal reflux disease.

Long term clinical performance of 'open sandwich' and 'total-etch' Class II composite resin restorations showing proximal deterioration of glass-ionomer cement.

OBJECTIVES: To compare clinical performance of resin composite posterior Class-II restorations placed with etch-and-rinse adhesive or open sandwich technique using glass-ionomer cement. METHODS: Data on Class II restorations placed by one dentist between 1990 and 2016 were collected from patient files, including caries risk, tooth related variables, applied materials and dates of last check-up visit and restoration placement. Open sandwich restorations were placed before 2001, while after 2001, a total-etch technique using etch-and-rinse 3-step adhesive was used when placing a Class II composite restoration. For statistical analysis, Kaplan-Meier statistics and a multilevel Cox-Regression was conducted (p < 0.05). Annual Failures Rates (AFR) were calculated. RESULTS: 675 Class II restorations were placed in 91 patients, 491 total-etch restorations (observation time 2-18 y), and 184 open sandwich restorations (observation time 19-29 y) showing AFRs at 15 years as 2.9 % for total-etch and 9.7 % for open sandwich restorations. Secondary caries as failure was equally distributed among the 2 groups and 27 % of the failures in the open sandwich group were due to proximal deterioration of glass-ionomer cement. The Cox-regression showed a significant higher risk for failure for the open sandwich technique compared to total-etch class-II composite restorations (HR = 2.9; p < 0.001). SIGNIFICANCE: Application of glass-ionomer cement using the open sandwich technique cannot be recommended for class-II restorations as being more complex and showing poorer clinical performance.

Managing tooth wear with respect to quality of life: an evidence-based decision on when to intervene.

Patients with more severe forms of tooth wear may require restorative rehabilitation. The decision to commence treatment must be taken carefully and there are a multitude of factors to consider. Alongside the clinical signs and symptoms typically associated with tooth wear, there is also the need to assess the impact of the condition on the patient's oral health-related quality of life. As part of the discussions relating to the attainment of informed consent for the restoration of the worn dentition, not only is it relevant to appropriately appraise the risks, benefits, costs, reasonable alternatives and likely prognosis of the proposed treatments, but to also elaborate on the expected impact of the intervention on the patient's oral health-related quality of life. The aim of this article is to review the evidence relating to the impact of the quality of life with the management of tooth wear, with the introduction of the concept of an evidence-based approach to decision-making when planning care.

Perception of oral health related quality of life and orofacial aesthetics following restorative treatment of tooth wear: A five-year follow-up.

OBJECTIVES: Non-carious tooth wear often has a multifactorial etiology and may lead to functional or aesthetically related problems. The most common complaints associated with tooth wear are dissatisfaction with dental appearance and a negative impact on the experienced Oral Health Related Quality of Life (OHRQoL). The aim of this study was to investigate the change in OHRQoL and the perception of aesthetics, following restorative treatment of moderate to severe tooth wear patients, with a five-year follow-up. METHODS: An explorative study, based on prospective data, was performed. OHRQoL and the perception of aesthetics were measured with the OHIP-NL and OES-NL. These questionnaires were completed before treatment, one month after treatment, and at 1-, 3- and 5-years post-treatment. Treatment involved full mouth reconstruction with composite resin restorations. The data was analysed as repeated measures by using a linear mixed-effects model. RESULTS: One hundred and twenty-three tooth wear patients that received restorative rehabilitation were included (97 males, 26 females, 37.5 ± 8.8 years-old). Data showed a statistically significant increase in both experienced OHRQoL and orofacial appearance after restorative treatment. The OHIP-scores remained stable over time, while the OES-scores slightly decreased during the years after treatment. Regarding the seven domains of the OHIP, the largest difference in OHIP-score was found in the domain of 'Psychological Discomfort'. The mean overall OHIP-score was 1.8 at baseline and 1.3 at the 5-years recall. The mean OES score increased from 41.8 at baseline to 66.1 at the 5-years follow-up. CONCLUSIONS: Tooth wear patients reported significant improvements in their OHRQoL and their perception of orofacial aesthetics after restorative treatment. This increase remained at least five years post-treatment. CLINICAL SIGNIFICANCE: The clinical impact of restorative treatment for tooth wear patients is considerable. This paper emphasizes the need to include a discussion of the patient related outcome measures when planning care.

Posterior Dahl: A Minimally Invasive Method for the Treatment of Localized Posterior Tooth Wear.

PURPOSE: This retrospective case series of 9 patients aimed to describe clinical outcomes and patient satisfaction following the implementation of the posterior Dahl concept to manage localized posterior tooth wear. MATERIALS AND METHODS: Localized occlusal space was created in the posterior dentition. Supra-occluding direct restorations were placed bilaterally for the restoration of molars. Intraoral scans were taken at the pre-treatment stage, immediately post-restoration, and during follow-up appointments. Scans were used to undertake analysis of any occlusal changes and re-establishment of the occlusion. A questionnaire was used to assess patient satisfaction, alleviation of any pre-treatment concerns, and evaluation of post-treatment complaints. RESULTS: Immediately post-treatment, all patients showed an increase in the vertical dimension. Opening of the bite in the untreated areas following restoration of worn posterior molars resulted either in a tendency towards or the actual reestablishment of the occlusion. One patient completely lacked compensatory vertical tooth movement in the untreated areas, culminating in the persistence of a vertical open bite. One restoration displayed cohesive fracture after 4 months. Pre-treatment problems (eg, sensitivity) were fully resolved amongst all patients after 6 months. Post-treatment complaints were minor and demonstrated resolution within a relatively short period of time. Eight patients reported being "very satisfied" with their treatment outcomes. CONCLUSION: Application of the posterior Dahl concept appears to offer a promising, relatively simple, minimally invasive and effective approach for the management of localized posterior tooth wear, which is well accepted by patients.

Proximal marginal overhang of composite restorations in relation to placement technique of separation rings.

The aim was to investigate in vitro the marginal overhang in Class II composite restorations placed with various separation rings and placement techniques. A total of 180 Mesial-Occlusal [MO] preparations in artificial molar teeth were divided into nine groups (n=20). After placement of the sectional matrix, one of three ring systems was applied: Contact Matrix System (Danville Materials), Composi-Tight Gold (Garrison), and V-Ring (Triodent). In each group, rings were placed according to four different techniques (V-Ring placed with technique no. 2 only): 1) occlusally of the wedge, 2) on back end of the wedge, 3) between adjacent tooth and wedge, and 4) between treated tooth and wedge.After application of the adhesive resin, preparations were restored with composite Clearfil AP-X (Kuraray) and polymerized in increments. After matrix removal, overhang was measured on a standardized digital macroscopic image in millimeters squared. For analysis, analysis of variance and Tukey B were used (p<0.05).For the Contact Matrix System and Composi-Tight Gold ring, the different placement techniques had a statistically significant effect on the amount of marginal overhang (p<0.031). The V-Ring resulted in the least marginal overhang (p<0.001).None of the placement techniques and separation rings could completely prevent marginal overhang, and the placement technique has a significant influence on its occurrence.

Rehabilitation of Worn Dentition with CAD-CAM Restorations: A Case Report.

PURPOSE: To describe the digital workflow applied for restoring a severely worn dentition with minimally invasive CAD/CAM resin nano-composite restorations. MATERIALS AND METHODS: A 40-year-old male in good general health and with full-arch dentition suffered from dentin hypersensitivity and wanted to improve the esthetics of his worn anterior teeth. The dental wear can be described as general, grade 3, according to the Tooth Wear Index,27 with more wear in maxillary than in mandibular teeth. Signs and symptoms were typical for a chemical type of wear, with some mechanical wear also apparent. No functional problems, eg, impaired chewing, were present. On the OHIP-49 questionnaire, the patient expressed a reduced quality of life. The goal of the treatment was to reconstruct the anatomical form of the teeth as far as possible, thereby also improving quality of life. Due to the rather large volume of lost tooth tissue per tooth, indirect treatment using CAD/CAM resin nano-composite restorations (LAVA Ultimate, 3M Oral Care) was applied. RESULTS: The seating of the CAD/CAM resin nano-composite restorations (LAVA Ultimate, 3M Oral Care) restorations was considered precise. CONCLUSION: In the treatment of severe tooth wear, the described digital workflow using CAD/CAM restorations for occluding restorations and direct composite materials in the esthetic zone is a potential treatment modality that is workable and minimally invasive.

Laboratory methods to simulate the mechanical degradation of resin composite restorations.

OBJECTIVES: This study reviewed the literature to identify in vitro approaches that have been used to simulate the mechanical degradation and fatigue of resin composite restorations. METHODS: A search for articles was carried out in 4 databases and included studies in which composite restorations were bonded to teeth and subject to cyclic loading. Articles were assessed for eligibility, and the following items were the extracted from the included studies: authors, country, year, materials tested, simulation device and details including load magnitude and frequency, number of cycles, type of antagonist, test medium, and temperature. Data were analyzed descriptively. RESULTS: The 49 studies included showed a high level of heterogeneity in methods, devices, and test parameters. Nineteen different simulation devices were used, applying loads varying between 30 and 2900 N, and frequencies varying between 0.4 and 12 Hz. The load and frequency used most often were ~ 50 N (63.3%) and 1.5-1.7 Hz (32.7%). The number of cycles varied between 10 K and 2.4 M, 1.2 M was the most prevalent (40.8%). The majority of studies combined cyclic loading with at least one additional aging method: static liquid storage, thermo-mechanical cycling applied simultaneously, and thermal cycling as a discrete aging step were the three most frequent methods. The overall evidence indicated reporting problems, and suggested a lack of clinical validation of the research methods used. SIGNIFICANCE: Validation studies, underlying clinical supporting data, and better reporting practices are needed for further improving research on the topic. Specific suggestions for future studies are provided.

The Ability of Two Chewing Simulation Devices in Emulating the Clinical Deterioration of Anterior Composite Restorations in Severely Worn Teeth.

PURPOSE: This study investigated the ability of two chewing simulation devices to emulate in vitro the clinical deterioration observed in anterior composite restorations in severe tooth-wear patients. MATERIALS AND METHODS: Advanced tooth wear was simulated in bovine incisors, which were restored with palatal and buccal direct composite veneer restorations. The incisal edges of restorations were subjected to 960K cycles of either compressive loading (Biocycle-V2; 125 N at 2 Hz) or wear and mechanical loading (Rub and Roll; 30 N at 20 rpm). Surface degradation was rated using FDI scores to compare the chewing devices (Fisher's test, a = 0.05). Topography and deterioration of restorations was analyzed using SEM. The ability to emulate the deterioration was investigated by comparing the surface degradation observed in vitro with the clinical degradation observed in restorations placed in severe tooth-wear patients after 3.5 years. RESULTS: Distinct degradation patterns were observed between the simulation devices: Biocycle-V2 generated deterioration that was not comparable to the clinical situation, including contact damage, minor wear, and localized roughening. The degradation caused by Rub and Roll was more similar to the in vivo situation, including wear facets, chipping, delamination, staining, and marginal ditching. The FDI scores were different between the chewing devices for surface/marginal staining, material/retention, and marginal adaptation (p = 0.003). SEM analysis showed microcracking at the interface between composite layers at the incisal edges. CONCLUSIONS: The Rub and Roll chewing device was able to emulate the clinical deterioration observed in anterior restorations in severe tooth-wear patients and thus may be used as an oral-cavity simulation method, contributing to translational research.