Is a blunt sword pointless? Tooth wear impacts puncture performance in Tasmanian devil canines.

As teeth wear, their shapes change and functional features can be dulled or lost, presumably making them less effective for feeding. However, we do not know the magnitude and effect of this wear. Using Tasmanian devil canines as a case study, we investigated the impact of wear on puncture in pointed teeth. We measured aspects of shape impacted by wear (tip sharpness, height and volume) in teeth of varying wear followed by 3D printing of real and theoretical forms to carry out physical puncture tests. Tooth wear acts in two ways: by blunting tooth tips, and decreasing height and volume, both of which impact performance. Sharper tips in unworn teeth decrease the force and energy required to puncture compared with blunter worn teeth, while taller unworn teeth provide the continuous energy necessary to propagate fracture relative to shorter worn teeth. These wear-modulated changes in shape necessitate more than twice the force to drive worn teeth into ductile food and decrease the likelihood of puncture success.

Hemoglobin Protects Enamel against Intrinsic Enamel Erosive Demineralization.

INTRODUCTION: This study investigated the changes in the acquired enamel pellicle (AEP) proteome when this integument is formed in vivo after treatment with sugarcane-derived cystatin (CaneCPI-5), hemoglobin (HB), and a statherin-derived peptide (StN15), or their combination and then exposed to an intrinsic acid challenge. The effectiveness of these treatments in preventing intrinsic erosion was also evaluated. METHODS: Ten volunteers, after prophylaxis, in 5 crossover phases, rinsed with the following solutions (10 mL, 1 min): control (deionized water-H2O) - group 1, 0.1 mg/mL CaneCPI-5 - group 2, 1.0 mg/mL HB - group 3, 1.88 × 10-5M StN15 - group 4, or a blend of these - group 5. Following this, AEP formation occurred (2 h) and an enamel biopsy (10 µL, 0.01 m HCl, pH 2.0, 10 s) was conducted on one incisor. The biopsy acid was then analyzed for calcium (Arsenazo method). The vestibular surfaces of the other teeth were treated with the same acid. Acid-resistant proteins in the residual AEP were then collected and analyzed quantitatively via proteomics. RESULTS: Compared to control, treatment with the proteins/peptide, mixed or isolated, markedly enhanced acid-resistant proteins in the AEP. Notable increases occurred in pyruvate kinase PKM (11-fold, CaneCPI-5), immunoglobulins and submaxillary gland androgen-regulated protein 3B (4-fold, StN15), Hb, and lysozyme C (2-fold, StN15). Additionally, a range of proteins not commonly identified in the AEP but known to bind calcium or other proteins were identified in groups treated with the tested proteins/peptide either in isolation or as a mixture. The mean (SD, mM) calcium concentrations released from enamel were 3.67 ± 1.48a, 3.11 ± 0.72a, 1.94 ± 0.57b, 2.37 ± 0.90a, and 2.38 ± 0.45a for groups 1-5, respectively (RM-ANOVA/Tukey, p < 0.05). CONCLUSIONS: Our findings demonstrate that all treatments, whether using a combination of proteins/peptides or in isolation, enhanced acid-resistant proteins in the AEP. However, only HB showed effectiveness in protecting against intrinsic erosive demineralization. These results pave the way for innovative preventive methods against intrinsic erosion, using "acquired pellicle engineering" techniques.

Should We Wait to Brush Our Teeth? A Scoping Review Regarding Dental Caries and Erosive Tooth Wear.

BACKGROUND: Tooth brushing is a universal recommendation. However, the recommendations related to the time of its execution are conflicting, especially when dealing with patients at risk of erosive tooth wear (ETW) or dental caries. SUMMARY: Our objective was to summarize the evidence on the timing of brushing with fluoridated toothpaste in relation to ETW and cariogenic dietary challenges. We conducted a scoping review following the PRISMA-ScR checklist, using three databases searching for in vivo, in situ, or in vitro studies involving human teeth exposed to either a cariogenic or an erosive challenge. Only models including human saliva and fluoride were assessed. Data selection, extraction, and risk of bias analysis were done in duplicate and independently. From 1,545 identified studies, 17 (16 related to ETW and 1 to dental caries) were included. Most evidence (n = 10) supported that brushing with a fluoride-containing product does not increase ETW, independent of the moment of brushing. Delaying tooth brushing up to 1 h (n = 4) or individualized recommendations based on the patient's problem (n = 2) were less frequent. Only one study reported that brushing pre- or post-meal does not affect Streptococcus mutans counts. Most data were in situ (n = 13), and the overall study quality was judged as sufficient/low risk of bias. KEY MESSAGES: Although the available evidence lacked robust clinical studies, tooth brushing using fluoridated products immediately after an erosive challenge does not increase the risk of ETW and can be recommended, which is in line with recommendations for dental caries prevention. Furthermore, we suggest updating the international guidelines to promote individualized recommendations based on risk factors to prevent either ETW or dental caries.

Quality of Patient-Centered eHealth Information on Erosive Tooth Wear: Systematic Search and Evaluation of Websites and YouTube Videos.

BACKGROUND: Due to the declining prevalence of dental caries, noncarious tooth defects such as erosive tooth wear have gained increased attention over the past decades. While patients more frequently search the internet for health-related information, the quality of patient-centered, web-based health information on erosive tooth wear is currently unknown. OBJECTIVE: This study aimed to assess the quality of patient-centered, web-based health information (websites and YouTube videos) on erosive tooth wear. METHODS: German-language websites were systematically identified through 3 electronic search engines (google.de, bing.de or yahoo.de, and duckduckgo.com) in September 2021. Eligible websites were independently assessed for (1) technical and functional aspects via the LIDA instrument, (2) readability via the Flesch reading-ease score, (3) comprehensiveness of information via a structured checklist, and (4) generic quality and risk of bias via the DISCERN instrument by 2 different reviewers. An overall quality score (ie, higher scores being favored) generated from all 4 domains was used as the primary outcome. Quality scores from each domain were separately analyzed as secondary outcomes and compared by the Friedman test. The effect of practice-specific variables on quality scores of websites from private dental offices was assessed using generalized linear modeling. Eligible YouTube videos were judged based on (1) the comprehensiveness of information, (2) viewers' interaction, and (3) viewing rate. The comprehensiveness of information was compared between websites and YouTube videos using the Wilcoxon rank-sum test. RESULTS: Overall, 231 eligible websites and 7 YouTube videos were identified and assessed. The median overall quality of the websites was 33.6% (IQR 29.8%-39.2%). Secondary outcome scores amounted to 64.3% (IQR 59.8%-69.0%) for technical and functional aspects, 40.0% (IQR 34.0%-49.0%) for readability, 11.5% (IQR 3.9%-26.9%) for comprehensiveness of information, and 16.7% (IQR 8.3%-23.3%) for generic quality. While the comprehensiveness of information and generic quality received low scores, technical and functional aspects as well as readability resulted in higher scores (both Padjusted<.001). Regarding practice-specific variables, websites from private dental offices outside Germany (P=.04; B=-6.64, 95% CI -12.85 to -0.42) or from dentists who are a dental society member (P=.049; B=-3.55, 95% CI -7.09 to -0.01) resulted in lower readability scores (ie, were more difficult to read), while a shorter time since dentists' examination resulted in higher readability scores (P=.01; B=0.24 per year, 95% CI 0.05-0.43). The comprehensiveness of information from YouTube videos was 34.6% (IQR 13.5%-38.5%). However, the comprehensiveness of information did not vary between websites and YouTube videos (P=.09). Additionally, viewers' interaction (1.7%, IQR 0.7%-3.4%) and viewing rates (101%, IQR 54.6%-112.6%) were low. CONCLUSIONS: The quality of German-language, patient-centered, web-based information on erosive tooth wear was limited. Especially, the comprehensiveness and trustworthiness of the available information were insufficient. Web-based information on erosive tooth wear requires improvement to inform patients comprehensively and reliably.

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.

Hard drugs use and tooth wear: a scoping review.

OBJECTIVES: This study aims to map evidence on the relationship between hard drug use and dental wear. The scoping review is guided by the question: What is the relationship between hard drug consumption and dental wear? MATERIALS AND METHODS: Adhering to PRISMA-ScR guidelines, searches were conducted across PubMed, Embase, and four databases in March 2024. Inclusion criteria included studies investigating the association between hard drug use and dental wear, regardless of publication date or language. Data were presented through narrative exposition, tables, and a conceptual framework. RESULTS: Twenty-eight studies (four case-control, three cross-sectional, five case reports, and sixteen literature reviews) were included. Among case-control studies, 75% observed an association between drug use and dental erosion; however, no cross-sectional studies demonstrated this association. Despite questionable quality, reviews established connections between drug use and dental erosion. Studies aimed to elucidate potential causes for dental erosion. CONCLUSIONS: Analysis suggests a potential link between hard drug use and dental wear, though indirect. Factors like bruxism and reduced salivary pH may contribute to dental wear among drug users. Further investigation through primary studies exploring this relationship is necessary. CLINICAL RELEVANCE: Dentists should focus not only on clinical characteristics of dental wear but also on mediating factors such as bruxism and decreased salivary pH associated with drug use. This holistic approach allows for a deeper understanding of dental wear mechanisms, enabling targeted preventive and therapeutic interventions.

Long-term occlusal tooth wear at the onset of permanent dentition.

OBJECTIVES: This study quantified the long-term occlusal wear in the natural posterior teeth and the associations per tooth type within the dentition. METHODS: The sample included 70 orthodontically treated subjects (52 females and 18 males; median age, 14.3 years), followed for a 12.7-year period. They were consecutively selected with no tooth wear-related criteria. Post-treatment (T1) and follow-up dental casts (T2) were scanned and superimposed through three-dimensional methods. Occlusal wear volume of posterior teeth and tooth wear patterns were investigated through non-parametric statistics and analysis of covariance. RESULTS: There were no significant differences between contralateral teeth. The average occlusal wear per posterior tooth was 2.3 mm3, with 65.2% of teeth showing values greater than 1 mm3. Males, mandibular teeth, and first molars exhibited slightly greater wear levels than females (median, 2.57 and 2.21 mm3, respectively; p = 0.005), maxillary teeth, and first or second premolars, respectively. In all first premolars and in the mandibular second premolars, the buccal cusps were primarily affected with no other distinct patterns. There were weak to moderate correlations between tooth types, apart from certain strong correlations detected in males. CONCLUSIONS: Posterior tooth wear was highly prevalent after a 13-year period starting at the onset of permanent dentition. The detected patterns are in accordance with the concept of canine guidance occlusion that is transforming into group synergy through function. CLINICAL RELEVANCE: The widespread tooth wear occurrence and the high intra- and inter-individual variability underline the need for individual patient monitoring to identify high-risk patients at early stages.

Tooth Wear Evaluation System 2.0-Evaluation of diagnostic reliability in the assessment of signs and symptoms for tooth wear by non-experts.

BACKGROUND: Tooth wear is a multifactorial condition that manifests through various signs and symptoms. These individual signs and symptoms were described in multiple studies, leading to the inclusion in TWES 2.0 (Tooth Wear Evaluation System 2.0) and the forthcoming DC-TW (Diagnostic Criteria for Tooth Wear). However, a study evaluating their reliability has yet to be conducted. OBJECTIVE: The aim of the study was to examine the reliability in the assessment of 6 signs of pathological tooth wear and 18 clinical signs and symptoms determining aetiology, all of which are included in the TWES 2.0/DC-TW. METHODS: 48 dental students (operators) evaluated patient cases from a patient pool of 14 patients on dental casts and high-resolution intraoral photographs. The agreement between all operators for each sign and symptom was calculated based on ICC (Intraclass Correlation Coefficients). Additionally, the agreement of each operator's evaluation with a predefined sample solution was calculated based on Cohen's kappa. RESULTS: Inter-user agreement ranged from near perfect (0.91) to poor (0.02) for the various pathology signs or aetiology symptoms of tooth wear (mean 0.32). The agreements of the operator's ratings compared to the sample solution resulted in Cohen's kappa from 0.18 to 1 (mean 0.59) for the pathology signs and ranged from 0.02 to 0.51 for the aetiology signs (mean 0.38). CONCLUSIONS: The reliability of the signs and symptoms examined and the ability of individual investigators to correctly identify and assign signs and symptoms varied widely. The current assessment tools for the qualification of tooth wear need further refinement, and examiners need intensive training in tooth wear assessment.

The bruxism screener (BruxScreen): Development, pilot testing and face validity.

BACKGROUND: To assess awake and sleep bruxism, the Standardised Tool for the Assessment of Bruxism (STAB) is currently being developed. The STAB will be a comprehensive tool for the detailed assessment of bruxism behaviour itself as well as of its possible consequences, causes, and comorbid conditions. OBJECTIVE: Since the STAB cannot fully meet the 'A4 principle' for a bruxism assessment tool, i.e., being Accurate (reliable and valid), Applicable (feasible), Affordable (cost-effective), and Accessible (suitable for everyday clinical use), the Bruxism Screener (BruxScreen) has been developed to be used in large-scale epidemiological research projects and, especially, in general, dental practices. METHODS: The BruxScreen consists of two parts: a questionnaire (BruxScreen-Q) to be completed by patients, and a clinical assessment form (BruxScreen-C) to be completed by dentists. RESULTS: This paper describes the development of the BruxScreen and provides the outcomes of the pilot testing phase and the face validity assessment (i.e. that the first impressions of the tool indicate that it adequately reflects the construct to be measured). CONCLUSION: The resulting BruxScreen is considered ready for more profound psychometric testing in the general dental setting.

Chewing performance of patients with worn dentition before and after restorations: A scoping review.

BACKGROUND: Tooth wear is a multifactorial complex process related to the loss of dental tissue, due to chemical or mechanical processes, by abrasion, attrition, erosion. Restorative treatment represents an attempt to rebuild and recreate the lost structure. OBJECTIVE: This scoping review aims to investigate whether restorative treatment of worn dentition (either with direct or indirect adhesive composite adhesive procedures or with prosthetic techniques) can have an impact on the masticatory performance parameters. METHODS: A scoping review was conducted on multiple databases (Pubmed, Medline CENTRAL, ICTRP), following the PRISMA guidelines. Abstracts of research papers were screened for suitability, and full-text articles were obtained for those who satisfied the inclusion and exclusion criteria. RESULTS: Only one article meet the inclusion criteria of the review. Restorative treatment of worn dentition although have a positive impact on the self-report ability to chew, has no effect on the masticatory performance test. CONCLUSION: At the moment, not enough evidence to comment on the actual therapeutic role of restorative treatment on tooth wear is available. Clinicians, before taking any clinical decision, should carefully discuss with patients the needs and expectations of the treatment plan.

Patients with gastroesophageal reflux disease (both reflux oesophagitis and non-erosive reflux disease): Prevalence and severity of erosive tooth wear and saliva properties.

BACKGROUND: The prevalence between erosive tooth wear (ETW) in association with reflux oesophagitis (RO) has been reported. However, the severity of both diseases and the relationship between ETW and non-erosive reflux disease (NERD) is unclear. OBJECTIVES: The prevalence and severity of ETW were investigated in RO, NERD and healthy controls. METHODS: 135 patients with RO, 65 with NERD and 40 healthy controls were recruited for this case-control study. A modified tooth wear index was used to evaluate the prevalence and severity of ETW. Salivary secretion and buffer capacity were assessed prior to endoscopy. The prevalence and severity of ETW, saliva properties among each group were analysed using Pearson's chi-squared test. RESULTS: A total of 135 cases (56.3%) were categorised as the patient with ETW (55 with mild RO, 49 with severe RO and 31 with NERD). There was a significant relationship between the prevalence of RO and ETW, while there was no significant correlation between the prevalence of NERD and ETW. There was a significant difference related to the severity between RO and ETW. For salivary secretion, there was a significant difference between with and without ETW in patients with mild RO, severe RO and NERD. There was a significant difference between with and without ETW for salivary buffer capacity in patients with mild and severe RO. CONCLUSION: There was a significant association of the prevalence and severity between RO and ETW. Clinical signs such as ETW and salivary buffer capacity depended on the severity of RO.

Factors associated with prevalence and severity of erosive tooth wear in patients with reflux oesophagitis.

BACKGROUND: Extrinsic factors for erosive tooth wear (ETW) have been widely reported, but the intrinsic factors for wear remain unclear. OBJECTIVES: The aim of this study was to evaluate the factors associated with the prevalence of ETW in patients with reflux oesophagitis (RO). To prevent severe ETW with RO, factors associated with severity of ETW were also evaluated. METHODS: A total of 270 patients with RO were recruited. A modified tooth wear index was used to evaluate the prevalence and severity of ETW. Salivary secretion and buffering capacity were assessed prior to endoscopy. Subjects were asked to complete a medical condition and oral self-care questionnaire. Univariate and multivariate analyses were employed to identify factors collectively associated with the prevalence and severity of ETW. RESULTS: A total of 212 cases were categorized as patients with ETW (148 with mild ETW and 64 with severe ETW). Multivariate analyses indicated that saliva secretion, severity of RO and proton pump inhibitor (PPI) resistance were associated with the prevalence of ETW, whereas age, BMI and severity of RO were associated with the severity of ETW. The odds ratio of saliva secretion and BMI were less than 1, meaning that higher saliva secretion resulted in a lower prevalence of ETW and lower BMI was associated with severe ETW. CONCLUSION: Saliva secretion, severity of RO and PPI resistance were associated with the prevalence of ETW, whereas age, BMI and severity of RO were associated with the severity of ETW. Lower saliva secretion and BMI were significant factors for ETW.

Development of toothpaste formulations containing mineral clays as abrasive agents and their effects on the physical properties of dental enamel.

To assess the physical properties and topographical aspect of dental enamel's surface microhardness (KHN), surface roughness (Ra), and color parameters CIELAB (∆Eab*), CIEDE 2000 (∆E00), and whiteness index for dentistry (∆WID) after toothbrushing with experimental toothpaste formulations with the following mineral clay types: kaolin, Sparclay SGY, and Tersil CGY used as abrasive component. Scanning electron microscopy (SEM) was performed for topographical analyses purposes. A total of 96 bovine incisors were used in the experiment. They were divided into eight experimental groups (n = 12), namely: NC-negative control (no treatment), CT12-Colgate Total 12®, CMP-Colgate® Máxima Proteção Anticáries, K-kaolin experimental toothpaste, SGY-Sparclay SGY experimental toothpaste; CGY-Tersil CGY experimental toothpaste, SD-SiO2 experimental toothpaste, and CC-CaCO3 experimental toothpaste. All samples were subjected to mechanical brushing protocol with 5000 cycles and kept in artificial saliva with daily exchanges. KHN was analyzed through the mixed linear model for repeated measures over time. Ra was analyzed through nonparametric Kruskal Wallis and Dunn tests to compare the groups. Paired Wilcoxon test was run to compare experimental times. ∆WID, ∆Eab*, and ∆E00 were analyzed through Kruskal Wallis and Dunn tests. All analyses were performed in R* software, at 5% significance level. EXP_SGY recorded higher KHN than EXP_SiO2 and EXP_CaCO3, whereas EXP_K showed increased Ra in comparison to CMP (p = 0.0229). ∆Eab and ∆E00 were significantly higher in the CT12, EXP_SiO2, and EXP_CaCO3 groups than in the NC and EXP_K (p < 0.0001). There were no significant changes in ∆WID (p = 0.0852). According to SEM results, toothbrushing with experimental toothpastes added with mineral clay types did not have significant impact on enamel's polishing and smoothness. CLINICAL RELEVANCE: Mineral clays have a broad application in the cosmetic industry, and recently, they have been used in the formulation of vegan toothpaste.

Systematic review and meta-analysis on prevalence and anamnestic risk factors for erosive tooth wear in the primary dentition.

BACKGROUND: Erosive tooth wear is a multifactorial and common condition in children. AIM: This systematic review and meta-analysis aimed to determine the prevalence and key risk factors for erosive tooth wear in the primary dentition of children up to 7 years of age. DESIGN: Electronic databases (PubMed, Embase, Scopus, and Web of Science) were searched in February 2023 for observational studies reporting prevalence and anamnestic risk factors. Additionally, a manual hand search was performed. Meta-analyses were conducted for the prevalence and odds ratios of identified risk factors. Risk of bias was assessed using the Newcastle-Ottawa scale modified for cross-sectional studies. RESULTS: A total of 26 sources, reporting on 23 studies, were included in the systematic review. The overall estimated prevalence of children with erosive tooth wear in the primary dentition amounted to 35.6% (95% CI: 24.8-48.1). Anamnestic factors were structured into domains. Meta-analyses revealed gastroesophageal reflux disease (GERD; padj. = .008; OR = 1.98, 95% CI: 1.37-2.87), consumption of acidic food (padj. < .001; OR = 5.14, 95% CI: 3.56-7.42) and acidic drinks (padj. < .001; OR = 6.90, 95% CI: 4.64-10.25), holding beverages in the mouth while drinking (padj. = .035; OR = 1.82, 95% CI: 1.26-2.63), and snacking regularly (padj. = .041; OR = 1.58, 95% CI: 1.18-2.10) to be significantly associated with erosive tooth wear. CONCLUSION: Future research should use standardized questionnaires to assess erosive tooth wear and its underlying risk factors (PROSPERO: CRD4202339776).

Erosive tooth wear among non-institutionalised older adults in Hong Kong: a cross-sectional study.

BACKGROUND: Non-institutionalised older adults is the majority of older adults in Hong Kong. The study aimed to examine erosive tooth wear (ETW) and its association with dental conditions and oral hygiene habits among non-institutionalised older adults in Hong Kong. METHODS: This cross-sectional study recruited dentate adults aged 60 or above from nine elderly daycare centres in the five main districts of Hong Kong. The study consists of a questionnaire survey and a clinical examination. A researcher used a questionnaire to collected the participants' demographic information, oral hygiene habits such as toothbrushing habits and dental visit behaviour. A calibrated examiner performed an oral examination in the daycare elderly centre to assess the ETW using basic erosive wear (BEWE) criteria. Oral hygiene was recorded using visible plaque index. Prosthetic status was recorded using the World Health Organization criteria. Logistic regression was used to examine the correlation between ETW and the dental conditions and oral hygiene habits. RESULTS: This study recruited 433 dentate adults and 333 adults were female (77%). Their age ranged from 60 to 99 years and their mean age was 74 years (SD = 7). They all had ETW (BEWE > 0). Over half of them (57%) had BEWE score of 3, indicating severe ETW. Analysis showed increasing age (OR = 1.030, p = 0.029) and older adults with untreated dental caries had higher odds (OR = 1.822, p = 0.002) of presenting severe ETW. No other associations were found between the ETW and the factors studied. CONCLUSION: Hong Kong non-institutionalised older adults aged 60 or above had ETW and more than half of them had severe ETW. Increasing age and having untreated dental caries were associated with severe ETW.

Practical training using BEWE aimed at improving the diagnosis ability of erosive tooth wear for dental students-A randomized trial.

INTRODUCTION: Erosive tooth wear (ETW) has been gaining attention due to its high prevalence. However, ETW clinical diagnosis is difficult and may go unnoticed by many professionals. The present study aimed to develop, implement and evaluate a theoretical-practical training using active methodologies in the development of undergraduate students' skills for the diagnosis of ETW compared to the traditional teaching method. MATERIALS AND METHODS: This randomized controlled study involved two parallel groups: control group (n = 22), with learning based only on theoretical content and test group (n = 24), learning by theoretical-practical activity mediated by monitors/tutors. The theoretical class covered the current concepts of ETW, aetiology, diagnosis, use of the BEWE index, prevention and treatment. The practical training included exercises and discussions based on the diagnosis using BEWE scores of a collection of images and extracted teeth. To evaluate the efficacy of the teaching-learning methods, a theoretical multiple-choice questionnaire and a practical test using images and extracted teeth were applied. The outcome was the number of correct answers. Groups were compared by Mann-Whitney (theoretical knowledge) and T tests (practical ability in diagnosis) (p < .05). RESULTS: There was no significant difference between groups in the theoretical evaluation (p = .866). The test group showed higher ability to diagnose ETW lesions compared to the control group in the practical tests (p = .001). The performance of ETW diagnosis was similar when images were used in comparison to extracted teeth (p = .570). CONCLUSION: The practical activity associated with theoretical classes can be a promising strategy to improve the development of undergraduate students' skills in the diagnosis of ETW.

An esthetic minimally invasive rehabilitation performed with a fully digital workflow and hybrid restorative approach.

AIM: The aim of the present study was to demonstrate that fully digital workflows can provide predictable esthetic and functional outcomes. MATERIALS AND METHODS: The present clinical case report provides a step-by-step documentation of a full-mouth rehabilitation planned and performed with a fully digital approach utilizing an adhesive and no-prep method. After assessing the patient's needs, a treatment plan was established that considered the patient's functional and esthetic requests. The overlap of 2D images and 3D models and facial scans of the patient allowed the digital previsualization of the esthetic result by implementing the "copy-paste" approach to restore the maxillary anterior sextant. CONCLUSION: The final outcome was satisfactory in terms of esthetics, function, and soft tissue health.

Progressive Tooth Wear Against Resin-Based Restorative Composites.

PURPOSE: The composition and properties of resin-based composite materials could affect tooth wear and lead to clinical problems. Therefore, the study objective was to characterize human tooth wear behavior against a bulk-fill restorative (BF) compared to a conventional resin composite (RC) and a CAD/CAM resin nano ceramic (RN). METHODS: Square-shaped specimens of each material were prepared and sub-divided according to the number of testing cycles (n=8): 100,000, 250,000, and 500,000 cycles. An occlusal wear test was performed using a chewing machine with 49 N, 2 Hz, in 37°C distilled water. Human premolar cusps were used as antagonists. Micro-CT and laser scanner were used to scan antagonists and specimens, respectively. Wear volume was assessed using a software and the wear pattern was examined with SEM. Softening in solvent analysis was performed by measuring the materials' Knoop microhardness (KHN) before and after immersion in ethanol. Wear volume data were analyzed with two-way ANOVA and Student-Neuman-Keuls test (α=0.05). RESULTS: For tooth and specimen wear volume, there was statistical significance for material and number of cycles, but not for the interaction between factors. BF resulted in less tooth (p=0.008) and specimen (p=0.030) wear than RN and RC, which were similar (p⟩0.05). Volume loss increased from 100,000 to 500,000 cycles. BF showed the lowest microhardness (KHN1); and %ΔKHN similar to RC, but greater than RN. CONCLUSION: BF induced less volume loss to the tooth than RC and RN, while presenting greater wear resistance. The tooth wear pattern and damage progression were mild for all materials. CLINICAL SIGNIFICANCE: Resin composites show favorable wear behavior, leading to low volume loss and mild structural damage of the tooth. Regular bulk-fill resin composite stands out for its efficient restorative technique, low wear susceptibility and reduced capacity to wear down the tooth.

Description of a new laboratory evaluation method of interdental brush abrasion as a clinical hazard.

OBJECTIVES: To simulate the abrasive potential of an interdental brush when applied with toothpastes and prophylactic gels/solutions in a novel laboratory brushing simulation set-up. METHODS: A brushing device was customized to treat dentin samples mimicking a simplified interdental space with an interdental brush (ISO 2). The brushing, that is, 7200 strokes for 1 h, was performed with artificial saliva (control), a povidone-iodine solution, and slurries of chlorhexidine and fluoride gels as well as three toothpastes with different RDA values ranging from 29 to 100, respectively. The loss of dentin was profilometrically assessed and compared with ANOVA and Fishers LSD. RESULTS: While artificial saliva as control, the solution and the gel slurries showed no measurable dentin loss, toothpastes resulted in a measurable linear surface damage with respect to the actual intrinsic RDA values and ranged from 12.6 to 26.5 µm (p < 0.001). CONCLUSIONS: Any interdental cleaning product should be tailored and carefully instructed. Any over- and misuse should be avoided, which applies especially to the use of interdental brushes in combination with abrasive toothpastes.

Sub-zero temperatures and large-scale weather patterns induce tooth damage in Icelandic arctic foxes.

Tooth damage in carnivores can reflect shifts in both diet and feeding habits, and in large carnivores, it is associated with increased bone consumption. Variation in tooth condition in Icelandic arctic foxes, a mesocarnivore, was recorded from 854 individual foxes spanning 29 years. We hypothesized that annual climatic variations, which can influence food abundance and accessibility, will influence tooth condition by causing dietary shifts toward less edible prey. We examined tooth condition in relation to four climatic predictors: mean annual winter temperature, indices of both the El Niño anomaly and North Atlantic subpolar gyre (SPG), and the number of rain-on-snow days (ROS). We found unequivocal evidence for a strong effect of annual climate on tooth condition. Teeth of Icelandic foxes were in better condition when winter temperatures were higher, when the SPG was more positive, and when the number of ROS was low. We also found a substantial subregional effect with foxes from northeastern Iceland having lower tooth damage than those from two western sites. Contradicting our original hypothesis that foxes from northeastern Iceland, where foxes are known to scavenge on large mammal remains (e.g., sheep and horses), would show the highest tooth damage, we suggest that western coastal sites exhibited greater tooth damage because cold winter temperatures lowered the availability of seabirds, causing a shift in diet toward abrasive marine subsidies (e.g., bivalves) and frozen beach wrack. Our study shows that monitoring tooth breakage and wear can be a useful tool for evaluating the impact of climate on carnivore populations and that climate change may influence the condition and fitness of carnivores in complex and potentially conflicting ways.