Rehabilitation of a Patient With Maxillary Defect and Severe Attrition Using Obturator Prostheses: A Case Report.

Surgery for palate lesions may result in oro-nasal/antral communication, which reduces a person's quality of life by affecting swallowing, speech, and food reflux. The shape and size of this obturator prosthesis might vary based on the severity of the defect. This case report describes the prosthetic rehabilitation of the patient with post-COVID mucormycosis and generalized attrition of teeth using an obturator and full mouth rehabilitation.

The Prevalence of Tooth Wear and Their Associated Etiologies Among Adult Subjects Visiting Umm Al-Qura University Dental Clinic in Makkah City, Saudi Arabia.

In the past two decades, changing trends in socioeconomic status, dietary habits, and individual lifestyles of individuals have led to the emergence of tooth wear as an oral health problem. The present study aimed to investigate the prevalence and the associated etiologies of tooth wear in a convenience sample of adult patients visiting outpatient clinics of the Faculty of Dentistry at Umm Al-Qura University. This cross-sectional study was conducted on adult patients (18-40 years old) visiting outpatient clinics of the Faculty of Dentistry, Umm Al-Qura University. Two trained examiners visually assessed patients' tooth wear using Smith and Knight's Tooth Wear Index (TWI). Following the clinical examination, patients completed a self-administered questionnaire detailing risk factors such as the frequency of intake of acidic food and medicines, general health, chewing habits, dietary factors, and oral health-associated preventive behaviors. The resulting collected data were tabulated and statistically analyzed using Statistical Product and Service Solutions (SPSS, version 21; IBM SPSS Statistics for Windows, Armonk, NY). The total prevalence of tooth wear was 74%, and the recorded mean wear score (TWI) was 0.380 ± 0.386; anterior teeth exhibited greater wear than posterior teeth. Numerous associations were recorded between tooth wear and the tested variables in demographics, habits, diet, and medications, but most of them were not statistically significant. When toothbrushing habits were explored, the only factors to played a significant role in abrading the tooth structure were the type of brush bristles used (P-value = 0.026) and the frequency of brush renewal (P = 0.043). Patients who frequently ate citrus fruits and other acidic foods recorded high wear scores (0.509 ± 0.311 and 0.508 ± 0.402, respectively), although the difference was not statistically significant. When chewing occurred on both sides of the mouth, less tooth wear was recorded than if chewing was on the right or left side only (0.371 ± 0.260, 0.422 ± 0.273, and 0.520 ± 0.419, respectively). The study data support an association between tooth wear and patient occupation, use of hard-bristled and new toothbrushes, eating of citrus and other acidic food, and chewing on one side, as all of these factors increased the risk of tooth wear.

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.

Insights into medieval rural lives: A paleo-odontological investigation of two central European communities.

OBJECTIVE: Oral status is an important indicator of past lifestyles. Determining the presence and extent of oral pathologies helps reconstruct average oral health, paramasticatory activities and diet of ancient and historical populations. DESIGN: In this study, the dental remains from the early medieval cemetery of Früebergstrasse in Baar (Canton of Zug, Switzerland) and the high medieval Dalheim cemetery (North Rhine-Westphalia, Germany) were analyzed. Caries, periodontal condition, periapical lesions, antemortem tooth loss, and enamel hypoplasia were assessed in 654 teeth (993 observable loci) from 68 individuals (Baar: n = 36; Dalheim: n = 32). RESULTS: The oral status of both populations was affected by age with higher values of tooth wear in advanced age individuals. High tooth wear values in both populations point towards the consumption of abrasive foods. Pronounced anterior tooth wear in Baar may also be due to non-masticatory tooth usage. Finally, possible nutritional deficiencies were hypothesized for the Baar population. A higher caries prevalence was observed in the Baar group, probably due to differences in carbohydrate intake. The oral conditions observed in the two studied populations exhibited several analogies, suggesting comparable lifestyles despite their separation in space and time. The only differences observed are related to the use of teeth as "tools" and are thus determined by behavioral choices rather than diverse socioeconomic factors. CONCLUSIONS: Using multiple dental parameters to examine the oral health of premodern individuals can provide useful insights into the interactions between humans and their environment, from dietary patterns to paramasticatory activities.

Tooth surface loss: causes, management and prevention.

OBJECTIVES: Tooth wear (TW), also referred to as tooth surface loss (TSL), occurs due to causes other than caries. This involves the loss of hard tissues, namely enamel, dentin and/or cementum. Types of TW/TSL are abrasion, abfraction, attrition and erosion. These multifactorial conditions can be caused things such as lifestyle, diet or even habits and may not be symptomatic. The focus of this article is to provide clinicians with detailed examples and explanations of the causes of tooth loss to aid in early diagnosis. Through early identification, the preventive measures outlined can be implemented to avoid excessive TW. The provision of a treatment flowchart and general treatment recommendations aims to help clinicians determine when to restore these lesions and the most appropriate treatment measures for the 4 types of wear. MATERIALS AND METHODS: The PubMed (MEDLINE) search engine was used to gather information on TW restricted to a five-year period (26 August 2018 - 25 July 2022). Only English-language studies and reviews with the best balance of sensitivity and specificity were considered. A Boolean search of the PubMed dataset was implemented to combine a range of keywords: ("tooth wear" OR tooth attrition OR tooth erosion OR tooth abrasion OR tooth abfraction). Additional articles were also selected through Google Scholar. RESULTS: By this process, many articles and studies were obtained, and the 48 most relevant published studies were chosen and used in the current review. The selected articles are in the reference list. CONCLUSION: TW affects an increasing number of individuals and can have detrimental effects physically, mentally and emotionally. It is important to stress early diagnosis and management of tooth wear through monitoring, prevention and treatment where indicated.

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.

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.

Cervical wear pathobiology by robot-simulated 3-year toothbrushing - New methodological approach.

OBJECTIVES: An ex-vivo study was aimed at (i) programming clinically validated robot three-year random toothbrushing, (ii) evaluating cervical macro- and microwear patterns on all tooth groups of different functional age, (iii) documenting and codificating wear related morphological features at the cemento-enamel junction in young teeth and on roots in older teeth. DESIGN: Following ethical approval random toothbrushing (44 strokes per tooth horizontally, rotating, vertically; 2x/d) with manual toothbrushes and low-abrasive dentifrice was performed in an artificial oral cavity with brushing-force 3.5 N on 14 extracted human teeth. Morphological features were examined by SEM at baseline and after simulated 3 years using the replication technique. 3D-SEM analyses were carried out with a four-quadrant back scattered electron detector. Wilcoxon-Mann-Whitney-test was used for statistical analyses. RESULTS: 3-year random toothbrushing with horizontal, rotating and vertical brushing movements revealed morphological features classified as four enamel patterns, one dentin pattern and three cervical patterns. Negative impacts were enamel, cementum and dentin loss. Positive impact on oral health was removing dental calculus and straightening cervical traumatic and iatrogenic damages. The volume loss varied from x̅=34.25nl to x̅=87.75nl. Wear extended apically from 100 to 1500 micrometres. CONCLUSION: Robot simulated toothbrushing in an artificial oral cavity, with subsequent SEM and 3D-SEM assessment, elucidated both negative and oral health-contributing micromorphology patterns of cervical wear after simulated 3-year random toothbrushing. Cervical macro- and microwear of cementum revealed, for the first time, what we describe as overhanging enamel peninsulas and enamel islands on roots in young teeth, but no enamel islands on roots from older teeth after root cementum loss. In contrast, many older teeth exhibited enamel peninsulas.

Tooth wear and bruxism: A scoping review.

OBJECTIVE: This study presents a scoping review to determine the association between tooth wear and bruxism. DATA: A protocol was developed a priori (Open Science Framework (DOI 10.17605/OSF.IO/CS7JX)). Established scoping review methods were used for screening, data extraction, and synthesis. Risk of bias was assessed using JBI tools. Direct associations between tooth wear and bruxism were assessed. SOURCES: Embase, SCOPUS, Web of Science, Cochrane, and PubMed were searched. STUDY SELECTION: Any clinical study containing tooth wear and bruxism assessment done on humans in any language was included. Animal, in-vitro studies and case reports were excluded. CONCLUSIONS: Thirty publications reporting on the association between tooth wear and bruxism were included. The majority of publications were cross-sectional studies (90%) while only three were longitudinal (10%). Eleven papers assessed definitive bruxism for analysis (instrumental tools), one paper assessed probable bruxism (clinical inspection with self-report) and eighteen assessed possible bruxism (self-report). Of the eleven papers assessing definitive bruxism, eight also reported outcomes of non-instrumental tools. Tooth wear was mostly scored using indexes. Most studies reported no or weak associations between tooth wear and bruxism, except for the studies done on cervical tooth wear. When bruxism assessment was done through self-report, more often an association was found. Studies using multivariate analyses did not find an association between tooth wear and bruxism, except the cervical wear studies. Evidence shows inconclusive results as to whether bruxism and tooth wear are related or not. Therefore, well-designed longitudinal trials are needed to address this gap in the literature. CLINICAL SIGNIFICANCE: Based on the evidence, dental clinicians should not infer bruxism activity solely on the presence of tooth wear.

Toothpaste containing TiF4 and chitosan against erosive tooth wear in situ.

OBJECTIVE: This study compared the protective effect of an experimental TiF4/Chitosan toothpaste with a commercial toothpaste on the prevention of erosive tooth wear (ETW) in situ. METHODS: Fifteen subjects took part in this crossover and double-blind study, in which they wore a palatal appliance containing 4 bovine enamel and 4 dentin in 3 phases (5 days each). Half of the samples were subjected to erosive challenges (90 s in 0.1 % citric acid, pH 2.5, 4 times/day), and the other half to erosive plus abrasive challenges (15 s plus 45 s of contact, 2 times/day). The phases corresponded to the application of the different toothpastes: 1) TiF4 (1400 ppm F-) plus Chitosan, 2) Elmex®, Erosion Protection (1400 ppm F-, Chitosan), and 3) Placebo (negative control). Tooth wear was measured using contact profilometry (µm) and submitted to two-way RM ANOVA/Tukey test (p < 0.05). RESULTS: No significant differences were detected between the experimental and commercial toothpastes, regardless of the challenge on both tissues. Both significantly reduce ETW compared to negative control (p < 0.0006). Tooth wear was increased by brushing only on eroded enamel (p < 0.01), but not on dentin (p = 0.6085). TiF4/Chitosan [erosion 2.98 ± 1.12 µm vs. erosion and abrasion 3.12 ± 1.33 µm] and Elmex® toothpastes [erosion 2.35 ± 0.93 µm vs. erosion and abrasion 2.98 ± 1.0 µm] minimized the impact of brushing compared to placebo on enamel [erosion 4.62 ± 1.48 µm vs. erosion and abrasion 5.15 ± 1.50 µm]. CONCLUSIONS: TiF4 plus chitosan toothpastes showed to be effective in minimizing the ETW as the commercial toothpaste is in situ. CLINICAL RELEVANCE: The experimental toothpaste has similar effect against ETW compared to the commercial toothpaste. Considering the increased ETW prevalence worldwide, this result supports clinical trials and a possible application of this experimental anti-erosive toothpaste in the future.

In vitro effect of fluoride gels supplemented with nano-sized sodium trimetaphosphate on enamel erosive wear.

OBJECTIVE: To assess the protective effect of fluoride (F) gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMPmicro and TMPnano, respectively) against enamel erosion in vitro. METHODS: Bovine enamel blocks (n = 140) were selected according to their surface hardness, and randomly divided into seven groups (n = 20/group), according to the gels tested: Placebo (without F/TMP), 4,500 µg F/g (4500F), 9,000 µg F/g (9000F), 4500F plus 2.5 % TMPnano (2.5 % Nano), 4500F plus 5 % TMPnano (5 % Nano), 4500F plus 5 % TMPnano (Micro 5 %) and 12,300 µg F/g (Acid gel). Blocks were treated once during one minute with the gels, and submitted to erosive (ERO, n = 10/group) or erosive plus abrasive (ERO+ABR, n = 10/group) challenges 4 times/day, for 90 s for each challenge (under reciprocating agitation), during consecutive 5 days. Blocks were analyzed by profilometry, and by surface (SH) and cross-sectional hardness (∆KHN). Data were submitted to two-way ANOVA, and Fisher's LSD test (p < 0.05). RESULTS: For ERO, both TMPnano-containing gels promoted enamel wear significantly lower than Placebo and 4500F, reaching levels similar to both positive controls (9000F and acid gel); significantly lower softening was observed for enamel treated with 4500F+5 % Micro and 4500F+2.5 % Nano. Also, the lowest ∆KHN values were observed for 4500F+2.5 % TMPnano among the TMP-containing gels. For ERO+ABR, the lowest enamel wear was achieved by the use of 4500F+5 % Nano among all gels, including both positive controls; lower softening was observed for Placebo and 9000F groups. CONCLUSION: The addition of 5 % nano-sized TMP to a low-fluoride gel produced superior protective effects for enamel under both challenges conditions, when compared with micrometric TMP, reaching values similar to or superior than both positive controls, respectively for ERO and ERO+ABR. CLINICAL SIGNIFICANCE: The supplementation of low-F gels with TMP was shown to significantly improve their effects on enamel erosive wear, and the use of nano-sized TMP further enhances this protective action.

Salivary factors associated with noncarious cervical lesions: A systematic review.

OBJECTIVE: This study aimed to carry out a systematic review of observational studies searching the association between salivary factors (amount and quality of saliva) and noncarious cervical lesions (NCCL) in individuals with permanent dentition. DESIGN: Cross-sectional, case-control, and cohort studies performed in humans with permanent dentition (population) and considering noncarious cervical lesions (outcome) in association with salivary characteristics (exposure) were included. PubMed, Web of Science, Cochrane, LILACS/BBO, Scopus, Embase, IBCT, NICE, OpenGrey, and Google Scholar were searched, with no language or date restrictions. Of 6561 potentially eligible studies, 142 were selected for full-text analysis. Three reviewers independently selected the studies, performed data extraction, and quality analysis through the Newcastle-Ottawa Scale. RESULTS: Finally, ten references were included in the review, four case-control and six cross-sectional studies. Several salivary parameters were evaluated. Some parameters were considered associated with the presence of noncarious cervical lesions: salivary buffering capacity, salivary pH, citric acid, and calcium and potassium levels. The methodological quality varied across studies, with high heterogeneity among them. CONCLUSIONS: Some associations between saliva and NCCL suggesting protective factors and others risk factors were found. However, the evidence is sparse and comes from a few studies with great heterogeneity. New scientific evidence, with standardized methods, should be encouraged. Understanding salivary parameters that influence the occurrence of NCCL is important to guide dentists in relation to etiological factors that could potentially be neglected. The results may help in the development of new and early diagnostic methods and treatments for noncarious cervical lesions.

Anamnestic risk factors for erosive tooth wear: Systematic review, mapping, and meta-analysis.

OBJECTIVES: Erosive tooth wear is a multifactorial condition. The aim of this systematic review and meta-analysis was to identify key risk factors for erosive tooth wear in permanent dentition. STUDY SELECTION: Observational studies reporting anamnestic risk factors for erosive tooth wear. Methodological quality and risk of bias were assessed using the modified Newcastle-Ottawa scale for cross-sectional studies. Risk factors were visually presented in a heatmap, and where possible, random-effects meta-analyses were performed for the odds ratios (ORs) of risk factors. SOURCES: Electronic databases (MEDLINE, Embase, Scopus, and Web of Science) and manual searches in February 2023. The protocol was registered in PROSPERO (CRD4202339776). DATA: A total of 87 publications reporting on 71 studies were included in the systematic review. The studies examined a variety of anamnestic risk factors (n = 80) that were categorized into ten domains (socio-demographics, socio-economics, general health, oral diseases, medication, oral hygiene, food, beverages, dietary habits, and leisure-related risk factors). Meta-analyses revealed significant associations between erosive tooth wear and male gender (padj.<0.001; OR=1.30, 95 % CI: 1.16-1.44), regurgitation (padj.=0.033; OR=2.27, 95 % CI: 1.41-3.65), digestive disorders (padj.<0.001; OR=1.81, 95 % CI: 1.48-2.21), consumption of acidic foods (padj.=0.033; OR=2.40, 95 % CI: 1.44-4.00), seasoning sauces (padj.=0.003; OR=1.28, 95 % CI: 1.13-1.44), nutritional supplements (padj.=0.019; OR=1.73, 95 % CI: 1.28-2.35), and carbonated drinks (padj.=0.019; OR=1.43, 95 % CI: 1.17-1.75). Most included studies exhibited low bias risk. CONCLUSIONS: Observational studies investigated a variety of anamnestic risk factors for erosive tooth wear. Future studies should employ validated questionnaires, particularly considering the most important risk factors. CLINICAL SIGNIFICANCE: Erosive tooth wear is a prevalent condition. Clinicians should concentrate primarily on symptoms of gastroesophageal reflux disease and dietary factors when screening patients at risk for erosive tooth wear.

5.5-year-survival of CAD/CAM resin-based composite restorations in severe tooth wear patients.

OBJECTIVES: Aim of this prospective study was to assess full mouth rehabilitation of severe tooth wear patients using minimally invasive CAD/CAM resin-based composite (RBC) restorations and direct veneers by evaluating restoration survival up to 5.5-years. METHODS: Twenty-two patients with generalized severe tooth wear with functional and/or esthetic problems were included. Following minimally invasive preparation, CAD/CAM RBC restorations (LAVA Ultimate,3M) were adhesively luted, direct RBC veneers (Filtek Supreme XTE, 3M) were applied in the aesthetic region. Patients were recalled after 1m,1y,3y,5y and seen in between recalls by their general dentists or at the clinical study center if complaints occurred. Failures were categorized as F1 (severe deficiencies requiring replacement/extraction), F2 (localized deficiencies requiring re-cementation/repair) and F3 (small chippings requiring refurbishment/monitoring). Survival of indirect restorations was evaluated using lifetables and Kaplan-Meier-graphs, distinguishing between failure categories and tooth type (front teeth=FT, premolars=PM, molars=M). F1 + F2 and F1 + F2 + F3 failures were analyzed using Cox regression on the variables tooth type/ location, age, gender and VDO increase (p < 0.05). RESULTS: 568 indirect restorations and 200 direct veneers in 21 patients evaluated for up to 5.5-years. For indirect restorations, 96 failures were recorded (F1:6;F2:41;F3:49) and annual failure rates were 0.29%(FT), 1.56%(PM), 2.93%(M) for F1 +F2 and 0.53%(FT), 2.42%(PM), 6.11%(M) for F1 + F2 + F3. Reasons for failure were chipping fracture (48), adhesive fracture (32), complete debonding (7), caries (4), endodontic treatment (1) and reasons unknown (documentation general dentists, 4). Molar tooth type had a statistically significantly increased probability of failure compared with front teeth and premolars for F1 + F2 + F3 (p < 0.006). Direct veneer restorations showed 18 failures (F1:2;F2:9;F3:7). SIGNIFICANCE: Minimally invasive CAD/CAM RBC restorations combined with direct RBC veneers showed an acceptable clinical mid-term survival for restorative rehabilitation of severely worn dentitions.

Complex dental wear analysis reveals dietary shift in Triassic placodonts (Sauropsida, Sauropterygia).

Placodonts were durophagous reptiles of the Triassic seas with robust skulls, jaws, and enlarged, flat, pebble-like teeth. During their evolution, they underwent gradual craniodental changes from the Early Anisian to the Rhaetian, such as a reduction in the number of teeth, an increase in the size of the posterior palatal teeth, an elongation of the premaxilla/rostrum, and a widening of the temporal region. These changes are presumably related to changes in dietary habits, which, we hypothesise, are due to changes in the type and quality of food they consumed. In the present study, the dental wear pattern of a total of nine European Middle to Late Triassic placodont species were investigated using 2D and 3D microwear analyses to demonstrate whether there could have been a dietary shift or grouping among the different species and, whether the possible changes could be correlated with environmental changes affecting their habitats. The 3D analysis shows overlap between species with high variance between values and there is no distinct separation. The 2D analysis has distinguished two main groups. The first is characterised by low number of wear features and high percentage of large pits. The other group have a high feature number, but low percentage of small pits. The 2D analysis showed a correlation between the wear data and the size of the enlarged posterior crushing teeth. Teeth with larger sizes showed less wear feature (with higher pit ratio) but larger individual features. In contrast, the dental wear facet of smaller crushing teeth shows more but smaller wear features (with higher scratch number). This observation may be related to the size of the food consumed, i.e., the wider the crown, the larger food it could crush, producing larger features. Comparison with marine mammals suggests that the dietary preference of Placochelys, Psephoderma and Paraplacodus was not exclusively hard, thick-shelled food. They may have had a more mixed diet, similar to that of modern sea otters. The diet of Henodus may have included plant food, similar to the modern herbivore marine mammals and lizards. Supplementary Information: The online version contains supplementary material available at 10.1186/s13358-024-00304-x.

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.

Are S-PRG composites able to resist against erosive and abrasive challenges and protect surrounding enamel in situ?

OBJECTIVES: This study evaluated the resistance of S-PRG (Surface Pre-Reacted Glass-ionomer) composites and other restorative materials against erosive and abrasive challenges and their protective effect on enamel adjacent to the restorations. MATERIALS AND METHODS: Bovine enamel blocks were prepared and randomized into 12 groups, including 6 types of material, each of them subjected to erosion_e or erosion+abrasion_ea: Beautifil II (S-PRG); Beautifil Bulk Restorative (S-PRG); Filtek Z250 XT; Filtek Bulk Fill; EQUIA Forte; Riva Light Cure. Cavities were prepared in the middle of enamel blocks and restored with the materials. Initial profiling measurement was performed on the material and on adjacent enamel (100, 200, 300, 600 and 700 µm from the restoration margin). Palatal intraoral appliances with the restored enamel blocks were used by the volunteers (n = 10). During 5 days appliances were immersed in 2.5 % citric acid for 2 min; 6 × /day (erosion_e). For ea condition, blocks were brushed for 1 min after each acid immersion. Final profile assessment was performed. Data were analysed by two and three way ANOVA followed by Tukey's test (p < 0.05). RESULTS: Material wear: Riva Light Cure showed the highest wear followed by EQUIA Forte and then all resin composites, including the ones with S-PRG (p = 0.000). Enamel wear: there was significant interaction among type of restorative material, wear condition and distance (p = 0.014), enamel around materials showed similar wear (p = 0.983) and the enamel subjected to ea exhibited highest wear (p = 0.000). CONCLUSION: SPRG based composites showed resistance against erosive and abrasive challenges but were not able to protect enamel adjacent to the restorations. CLINICAL SIGNIFICANCE: S-PRG composites exhibit resistance to material wear comparable to resin composites. However, they have shown an inability to effectively protect the adjacent enamel under in situ erosive-abrasive conditions, despite the presence of mineral-loss-preventing ions surrounding materials.

Characteristics of tin-containing fluoride toothpastes related to erosive tooth wear protection.

OBJECTIVES: To assess the effect of different tin-containing toothpastes on the control of erosive tooth wear in enamel and dentin. METHODS: Enamel and dentin slabs were randomly distributed into 7 experimental groups (n = 10/substrate): C-: negative control (Artificial saliva); AmF (regular fluoridated toothpaste without tin); Sn-1 (SnF2/NaF); Sn-2 (SnF2/NaF/SnCl2); Sn-3 (SnCl2/NaF); Sn-4 (SnF2/SnCl2); Sn-5 (SnCl2/AmF/NaF/chitosan). Specimens were submitted to 5-day erosion-abrasion cycling. Surface loss (SL) was determined with an optical profilometer. Tin deposition on the tooth surfaces and some characteristics of the toothpastes (pH, potentially available F-, %weight of solid particles, and RDA) were also assessed. Data were statistically analyzed (α = 0.05). RESULTS: For enamel, the Sn-2 presented the lowest SL, not differing significantly from AmF, C+, and Sn-3. The SL of these groups was significantly lower than the C-, except for Sn-3. Sn-1 and Sn-4 were also not significantly different from C-. For dentin, C- significantly showed the highest SL values, whilst, Sn-1 presented the lowest SL, not differing significantly from AmF, Sn-2, C+, and Sn-3. There was a significant positive association between enamel SL and the pH and tin deposition. Dentin SL was significantly negatively associated with the %weight of solid particles and RDA. CONCLUSIONS: Most of the tin-toothpastes were able to exhibit some protection against ETW. In this process, the toothpastes characteristics play a role, as lower enamel SL was significantly associated with lower pH values and tin deposition; and lower dentin SL was associated with higher %weight of solid particles and RDA of the toothpastes. CLINICAL SIGNIFICANCE: Tin-containing toothpastes can be used for erosive tooth wear protection, but our study showed that their effect depends on the pH, amount of tin deposition, % weight of solid particles and RDA of the toohpastes.

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.