Information about the use of stone tools in the past is encoded in the wear patterns left on their surface; however, post-depositional processes can modify and obstruct these traces. One aim in the field of lithic functional analysis is to develop methods to detect and quantify these traces on stone tools. The occlusal fingerprint analysis (OFA) is a well-established method in dental wear studies to virtually simulate dental occlusal (contact between teeth) stroke movements and thus locate and quantify the sequential contact between opposing tooth crowns. Reaching across disciplines, we conducted controlled experiments to test the applicability of the OFA method on stone tools to address the challenge of use-wear quantification and localisation, and therefore the identification of post-depositional wear. Our findings reveal a clear overlap between zones of experimentally produced use-wear and OFA-calculated contact areas. We demonstrate OFA as a potential method to generate models of multiscale use-wear that can be used as references on experimental tools to identify post-depositional surface modifications on stone tool artefacts.

The aim of this in vivo study was to compare total protein present in the salivary films (F) and acquired enamel pellicle (AEP) on eroded and non-eroded surfaces in patients suffering from GORD symptoms with and without GORD diagnosis (GORD, No-GORD). Thirty-nine patients suffering from GORD symptoms and erosive tooth wear on lower first molars and an unaffected posterior occlusal surface in the same quadrant were recruited from Guy\'s hospital, London. Salivary film and AEP were collected from the eroded and uneroded occlusal surfaces, using 0.5% sodium dodecyl sulphate (SDS)-soaked filter papers. Total protein concentration was analysed using bicinchoninic acid assay (BCA). Statistical analysis was conducted using Shapiro-Wilk, ANOVA, and Tukey\'s tests (p < 0.05), comparing four GDS sample types and GORD vs. No-GORD groups. The level of significance was set as p < 0.05. Data were compared between eroded and uneroded surfaces in the same patient with GORD symptoms, as well as between those with or without a GORD diagnosis (GORD, No-GORD). The AEP total protein concentration from the eroded [2.17 (0.49) mg/mL] and uneroded surfaces [2.24 (0.66) mg/mL] of the GORD group were statistically significantly lower than those on eroded [3.27 (1.01) mg/mL] and uneroded [3.33 (1.57) mg/mL] surfaces in the No-GORD group (p = 0.007) (p = 0.008), respectively. No statistically significant differences were observed for film and AEP between eroded and uneroded surfaces (p > 0.05).

Ornithopod dinosaurs evolved numerous craniodental innovations related to herbivory. Nonetheless, the relationship between occlusion, tooth wear rate, and tooth replacement rate has been neglected. Here, we reconstruct tooth wear rates by measuring tooth replacement rates and tooth wear volumes, and document their dental microwear. We demonstrate that total tooth volume and rates of tooth wear increased steadily during ornithopod evolution, with deeply-nested taxa wearing up to 3360 mm3 of tooth volume/day. Increased wear resulted in asymmetric tooth crown formation with uneven von Ebner line increment width by the Late Jurassic, and in faster tooth replacement rates in multiple lineages by the mid-Cretaceous. Microwear displays a contrasting pattern, with decreasing complexity and pit percentages in deeply-nested and later-occurring taxa. We hypothesize that early ornithopods were browsers and/or frugivores but deeply nested iguanodontians were bulk-feeders, eating tougher, less nutritious plants; these trends correlate with increasing body mass and longer gut passage times.

The basal macronarian sauropod Europasaurus holgeri is known only from the Late Jurassic of the Langenberg Quarry near Goslar, Lower Saxony, Germany. Europasaurus has been identified as an insular dwarf and shows a clear resemblance to Camarasaurus and Giraffatitan. This study provides a detailed description of the dentition of Europasaurus based on an array of fossils outstanding in their abundance, variety of preservation, and ontogenetic range. Dental morphology for the replacement and functional dentitions, the tooth replacement pattern, and implications for food intake are described for the Europasaurus dentition, which is characterized by broad-crowned teeth. Characteristic features for Europasaurus are the presence of denticles on replacement teeth, the wrinkled enamel, and large wear facets both on the apex and on the carinae of the tooth crowns. The partially articulated skull SNHM-2207-R and isolated tooth rows DfmMh/FV 580.1 and DfmMh/FV 896.7 suggest the presence of strong connective tissue partially covering the teeth. This connective tissue would have provided stability and protection for the teeth. Evidence for this connective tissue include exposed tooth necks, in-situ teeth with strongly resorbed roots which no longer would have been connected to the jaw bone, and wrinkled enamel and its surface pattern. The same features can be observed in other sauropod taxa as well. We therefore suggest that eusauropods in general possessed this connective tissue structure, which may be an autapomorphy of the group. Possibly, this hypothetical structure is homologous to the rhamphotheca in birds and some non-avian theropods, which, however rarely, show such a close integration of keratinous tissue and teeth that we hypothesize here.

UNASSIGNED: Early detection and management of tooth wear (TW) has not been given due consideration in the dental profession. Thus, this study aimed to explore the prevalence of TW in adults with diabetes in Dakshina Kannada population using the Basic Erosive Wear Examination (BEWE) and recording its impact on quality of life using the Oral Health Impact Profile (OHIP-14).
UNASSIGNED: In total, 236 dentate adults with diabetes and TW, who visited the Manipal College of Dental Sciences, Mangalore were recruited to the study. Assessment of TW was done using BEWE during examination of each participant and was categorized as none, mild, moderate, and severe. Impact of TW on quality of life was assessed using the OHIP-14.
UNASSIGNED: Overall, 81 (34.30%) individuals had a poor score on the basic erosive tooth index, 82 (34.70%) had a medium score, . The level of TW, both moderate and severe (high), affected quality of life. Erosion, abrasion and attrition were seen in a large proportion of the study population. The diabetic status of the individual was collected from their medical file. The HbA1C level was found to range from good, fair and poor control. The quality of life among the study population was affected because of TW and diabetes. Few participants had hypertension along with diabetes. The majority of study participants were on oral hypoglycaemic agents. Participants used tooth brushes and tooth paste and brushing frequency varied between once or twice daily.
UNASSIGNED: In the study population, there were moderate and severe TW patterns. Quality of life was found to be impacted by TW. Dental professionals must give proper consideration to the influence of TW on quality of life in addition to clinical findings. This will make it easier to offer preventive or restorative management depending on the situation.

BACKGROUND: The risk assessment of dental erosion among children and adolescents is an important aspect of dental care, as dental erosion constitutes a rapidly growing, global problem. Dental professionals rely solely on their own perception, as the current risk assessment process is not completely automatized, which affects the risk assessment reliability.
OBJECTIVE: To explore dental professionals\' experiences with risk assessment of dental erosion among children and adolescents.
METHODS: In-depth interview was used as data collection method. A total of 11 dental professionals were interviewed. The interviews were analyzed using qualitative content analysis.
RESULTS: The findings were summarized in the categories Professionals\' responsibility, Systematic approach , and Collaboration and communication. Dental staff perceived that their basic knowledge regarding erosion should be improved, and skills development was desired to reduce the knowledge gaps around the risk assessment of dental erosion. They alleged that the systematic approach could be improved by reducing workplace stress, implementing a universal dental erosion index, improving the existing risk assessment software, and automating the risk assessment of the condition. Dental professionals also experienced a need to calibrate and collaborate with each other and with other healthcare professionals to improve patient care.
CONCLUSIONS: Dental professionals experienced their basic knowledge of dental erosion and their risk assessment as good, but a more advanced skill development was required. Furthermore, they experienced the risk assessment software as a good tool that should be improved to compile more objective risk assessment. A universal erosion index was also requested.

Objective To evaluate the survival and clinical performance of restorative materials used in the rehabilitation of generalised severe tooth wear within a UK NHS postgraduate teaching hospital.Methods The clinical performance of 527 restorations on 20 patients with generalised severe tooth wear was reviewed after a mean period of five years. Anterior teeth were restored with direct composite resin and posterior teeth with indirect restorations. The study used the modified United States Public Health Service criteria for restoration assessment. Survival of the restorations was analysed using Kaplan-Meier survival curves, the log-rank test and the Cox proportional hazards regression analysis.Results The sample included 20 participants: 13 men and 7 women, with a median age of 51.8 years (range: 33-73 years). The median survival time for all restorations was 11.3 years when major failures were considered and 5.9 years for restorations when all types of failure were considered. A median survival time of 5.9 years for composite resin restorations and over seven years for cast restorations was found when considering all failures. Composite resin restorations commonly failed as a result of fracture, wear and marginal discolouration. Factors significantly influencing restoration survival were the material used, aetiology, incisal relationship and tooth location. The biological complications associated with this treatment regime were rare. Patient satisfaction remained generally high, with greatest dissatisfaction related to treatment time.Conclusions The use of anterior composite resin with posterior indirect restorations to treat generalised severe tooth wear is a viable treatment modality with very few major complications.

UNASSIGNED: Multilayer zirconia has more optical and aesthetic features than regular zirconia. Therefore, its mechanical properties should be compared with monochromatic zirconia. Among the mechanical characteristics that can be checked are the wear of the opposite tooth and the bond to the porcelain. This study assessed the effect of zirconia type (multilayer versus monochromatic) on the shear bond strength (SBS) to feldspathic porcelain and the wear of the opposing teeth.
UNASSIGNED: The present in vitro study was conducted in two phases. In the first phase, 15 multilayer and 15 monochromatic zirconia blocks measuring 10×5×5 mm were designed, milled, sintered, veneered with porcelain, and underwent thermocycling. Their SBS was then measured in a universal testing machine. In the second phase, 15 multilayer and 15 monochromatic zirconia blocks were placed in a chewing simulator, and 30 sound premolars served as antagonistic teeth. The magnitude of wear of the buccal cusp of premolars was quantified from a 4-mm reference point after 100000 cycles. Data were analyzed by independent t test (α=0.05).
UNASSIGNED: The mean SBS of monochromatic zirconia to porcelain (24.49±3.58 MP) was slightly higher than that of multilayer zirconia (22.98±2.98 MP), but the difference was not significant (P>0.05). The mean wear of the opposing teeth was also slightly higher in the monochromatic group (284.1±66.53 µm) than in the multilayer group (263.2±58.69 µm), but this difference was not significant either (P>0.05).
UNASSIGNED: Monochromatic and multilayer zirconia showed comparable SBS to feldspathic porcelain and caused comparable wear of the opposing teeth in vitro. Thus, multilayer zirconia may serve as an alternative to monochromatic zirconia.

Intraoral scanners are widely used in a clinical setting for orthodontic treatments and tooth restorations, and are also useful for assessing dental wear and pathology progression. In this study, we assess the utility of using an intraoral scanner and associated software for quantifying dental tissue loss in non-human primates. An upper and lower second molar for 31 captive hamadryas baboons (Papio hamadryas) were assessed for dental tissue loss progression, giving a total sample of 62 teeth. The animals are part of the Southwest National Primate Research Center and were all fed the same monkey-chow diet over their lifetimes. Two molds of each dentition were taken at either two- or three-year intervals, and the associated casts scanned using an intraoral scanner (Medit i700). Tissue loss was calculated in WearCompare by superimposition of the two scans followed by subtraction analysis. Four individuals had dental caries, and were assessed separately. The results demonstrate the reliability of these techniques in capturing tissue loss data, evidenced by the alignment consistency between scans, lack of erroneous tissue gain between scans, and uniformity of tissue loss patterns among individuals (e.g., functional cusps showing the highest degree of wear). The average loss per mm2 per year for all samples combined was 0.05 mm3 (0.04 mm3 for females and 0.08 mm3 for males). There was no significant difference in wear progression between upper and lower molars. Substantial variation in the amount of tissue loss among individuals was found, despite their uniform diet. These findings foster multiple avenues for future research, including the exploration of wear progression across dental crowns and arcades, correlation between different types of tissue loss (e.g., attrition, erosion, fractures, caries), interplay between tissue loss and microwear/topographic analysis, and the genetic underpinnings of tissue loss variation.

Bruxism has been defined in recent years and analyzed in detail as the repetitive activity of the muscles of the masticatory system. Both adults and children experience two different forms of bruxism: daytime and nighttime bruxism. According to the WHO, bruxism affects 5% to 50% of the world\'s pediatric population. The symptoms of this disease include tooth wear and fractures, temporomandibular disorders, headaches, behavioral and sleep disorders, and parafunctional habits such as nail biting. According to scientists, psychosocial factors are the most likely factors causing bruxism in children. To this day, we do not have established standards of treatment for children, especially for those with disabilities. The issue of bruxism in children with Down syndrome (DS) is still unexplained. Anatomical abnormalities in the facial skeleton, reduced muscle tone, personality traits, and sleep problems in these people may cause the symptoms of bruxism. Our study aimed to present a clinical case of a 13-year-old girl with DS and symptoms of bruxism. Diagnostics and dental examination in children with intellectual disabilities and a lack of understanding of the disease create a great challenge for the treatment team, including the dentist, physiotherapist, psychologist, and family. Creating standards for treating and preventing bruxism symptoms is demanding, among other things, due to the lack of sufficient scientific research.