Academic Center for Dentistry Amsterdam

Salivary dysfunction, including xerostomia and drooling, is common in Parkinson's disease and further impairs oral health and quality of life, which are already compromised in this population. Their effective management demands deeper insight into the complexity of salivary dysfunction. To examine the occurrence and associations of xerostomia and drooling complaints in individuals with Parkinson's disease. 111 individuals with Parkinson's disease (69.9 ± 7.7 years; 46.8% female) participated in an online survey. The questionnaire used validated scales (e.g., Xerostomia Inventory) and original questions. After descriptive analyses, multiple linear regression analyses identified factors (e.g., severity of motor impairment) associated with severity of xerostomia and drooling. Xerostomia (64.9%) and drooling (27.0%) were common, with 18.0% of the individuals experiencing both concurrently. Xerostomia was associated with the presence of jaw symptoms (B = 4.63; 95% CI 1.86-7.40), chewing gum usage (B = 1.27; 95% CI 0.52-2.02), swallowing difficulties (B = 0.41; 95% CI 0.04-0.78) and taste alterations (B = 0.15; 95% CI 0.00-0.30). Drooling was associated with the severity of motor impairment (B = 0.40; 95% CI 0.18-0.60) and with swallowing difficulties (B = 0.64; 95% CI 0.14-1.15). Xerostomia and drooling complaints frequently co-occur in individuals with Parkinson's disease. To prevent further deterioration of the oral health-related quality of life, a comprehensive evaluation of the underlying aetiology of salivary issues in people with Parkinson's disease is crucial to assist in determining suitable treatment.

Peer interactions in early childhood education and care (ECEC) contribute to young children’s development. Earlier studies show that children’s linguistic resources might relate to how much they interact with peers, and with whom they interact. However, it is unclear to what extent interaction preferences are shaped by young children’s language background, language proficiency, and communicative competence. In this exploratory study, we tried to examine this question using the latest innovations in social network analysis, namely generalized exponential graph models and observation apps. We investigated to what extent children’s linguistic resources are related to whom they interact with and how much. We observed a free play episode (30-60 minutes) in twelve linguistically diverse toddler groups in the Netherlands (N=124) with a specifically designed observation app and looked at which children interacted and how much. Exploratory analyses across nine playgroups showed that children who shared a home language had more interactions with each other. There was no effect of multilingualism or ECEC language proficiency on peer interactions. We found that teacher involvement in free play was positively related to the quantity of peer interactions. In terms of practical implications, this suggests that teachers play an important role in stimulating (multilingual) children’s peer interactions in ECEC. Teachers might be advised to connect multilingual children to same-language peers and encourage translanguaging practices. • We studied toddlers’ peer interactions in relation to their linguistic resources • A dedicated observation app and generalized exponential graph models were used • Children who shared a home language had more interactions with each other • There was no effect of multilingualism or language proficiency on peer interactions • Teacher involvement during free play was positively related to peer interactions

To evaluate the biomechanical behavior of bilayer crowns with traditional and modified core designs using fatigue survival testing and finite element analysis (FEA), aiming a suitable rehabilitation for the anterior teeth area. Forty-five crowns were manufactured, according to the following groups: CC (conventional core), MCS (modified core/stratified veneer) and MCM (modified core/machined veneer). Cores were machined (lithium disilicate); veneers of CC and MCS groups were made through stratification (fluorapatite), and veneers of MCM group were also machined (leucite). Next, the crowns were cemented using resin cement (Variolink Esthetic LC) over full crown preparations made of epoxy resin and then subjected to cyclic fatigue test. After mechanical testing two events were considered: the presence of crack and/or chipping (event 1) and catastrophic failure of the crown (event 2). The average load to failure and number of cycles to failure in which events 1 and 2 occurred were used to perform the survival analysis according to Kaplan-Meier and Log-Rank (Mantel-Cox; 95%). Fracture marks and failure mode of the crowns were evaluated and classified by optical stereomicroscope and scanning electron microscope. Finally, FEA was performed to evaluate the stress distribution on the crowns. Fatigue test results showed that considering event 1 the groups with modified cores (MCS: 1020N and MCM: 913N) presented higher average loads and number of cycles to failure than the group CC (773N). Considering event 2 all groups showed similar fatigue performance (∼1028N). FEA results evidenced higher stress concentration at the load application area, with a slight stress at the cervical margin of the crowns regardless the group. Modified core designs improved resistance to initial veneer damage without compromising catastrophic failure performance. Stress distribution patterns supported the mechanical findings, indicating favorable biomechanical behavior.

To assess how resin cement viscosity and thickness influence the static shear bond strength (s-SBS) of adhesively bonded lithium disilicate ceramic. Cylindrical lithium disilicate samples were prepared and randomly assigned to four experimental groups (n = 10), based on two factors: resin cement thickness (thin ≈50 µm or thick ≈150 µm) and viscosity (high or low). A tri-layer configuration (ceramic-resin cement-ceramic) was used, with standardized ceramic discs obtained from CAD/CAM blocks. The bonding ceramic surfaces were etched with hydrofluoric acid, silanized, and a defined bonding area (≈6 mm2) was delimited using adhesive tape. The resin cement thickness was controlled by applying either one (thin) or three (thick) overlapping layers of adhesive tape. Resin cement was applied, and assemblies were seated under a 100 g static load. After light-curing, specimens were subjected to static shear bond strength testing (s-SBS) using a universal testing machine (crosshead speed: 1 mm/min; load cell: 1 kN). Failure mode was classified under stereomicroscopy, and representative samples were analysed under SEM. Additional specimens were used to confirm cement layer thickness using a profilometer. For the thick resin cement layer (≈150 µm), viscosity significantly influenced bond strength, with high-viscosity cement showing higher mean values (27.36 MPa) compared to the low-viscosity cement (19.65 MPa). In contrast, resin cement viscosity did not affect the bond strength in the thin layer condition (≈50 µm). Most specimens exhibited adhesive failure at the ceramic-cement interface. Resin cement selection based on viscosity is particularly relevant when a thick cement layer is anticipated, whereas for ideal, thin cement films, viscosity is a less consequential factor for interfacial bond strength.

ObjectivesTo investigate the monotonic and fatigue strength of 3D-printed 5 mol% yttria partially stabilized zirconia (5Y-PSZ) and the influences of printing layer orientation and finishing protocol.MethodsBar-shaped 5Y-PSZ specimens (1.0 mm x 1.0 mm x 12.0 mm) were 3D-printed via stereolithography, followed by debinding and sintering. The specimens were randomly divided into 2 groups according to printing layer orientations: parallel or perpendicular to the tensile surface of a 3-point bending test. The specimens of each printing layer orientation were subsequently submitted to different surface finishing protocols: as-sintered, polished, and glazed. The monotonic strength of each group was determined using a ball-in-hole device. A step-wise fatigue test was conducted for the polished and glazed specimens.ResultsFor monotonic strength, the parallel specimens (640 ± 99 MPa) were stronger than the perpendicular (507 ± 48 MPa); polishing generated higher strength for both parallel (782 ± 134 MPa) and perpendicular (645 ± 160 MPa) orientations; while the effect of glazing was not significant, the glazed perpendicular specimen (623 ± 97 MPa) presented similar strength to the glazed parallel specimens (581 ± 117 MPa). However, the fatigue strength was similar in the evaluated groups (parallel and polished: 418 ± 115 MPa; perpendicular and polished: 404 ± 55 MPa; parallel and glazed: 406 ± 41 MPa; perpendicular and glazed: 371 ± 86 MPa).ConclusionBoth printing layer orientation and surface finishing influenced the monotonic strength of 3D-printed 5Y-PSZ, while fatigue strength did not differ significantly among polished and glazed specimens with different orientations.

Oral health is critical for overall health and well-being, especially in older people. However, the frequency of dental visits tends to decrease as individuals age. In contrast, frail older people who are less likely to visit the dentist, increasingly rely on medical care, such as the general medical practitioner (GP). There is a lack of quick and efficient screening tools for GPs to assess the risk of oral health deterioration. This study aims to develop a short screening tool to provide GPs with a quick, easy-to-use tool to predict oral health deterioration in older people, enabling timely referral and intervention when needed. The study consisted of three phases. In phase 1, the research team preliminary selected themes and items based on their predictive value, following a prior systematic review. In phase two the English self-reporting items were translated into Dutch, following cross-cultural adaptation guidelines. In phase 3 a panel of experts was selected and a Delphi method was conducted to develop the SHORT screening tool. The preliminary selection resulted in thirteen self-reporting items. Translation and back-translation proceeded without difficulties. The Delphi panel included 10 healthcare professionals and consisted of three rounds, after which consensus was achieved for the inclusion of three self-reporting items in the tool (100% agreement; median score = 5; IQR = 0). The SHORT screening tool was developed, including a preliminary selection of items, translation, and the Delphi method, which was successful in achieving consensus. Further research is recommended to validate and test the psychometric properties of this newly developed screening tool. - The SHORT tool provides a quick, three-item screening method for general practitioners to identify older people at risk for oral health deterioration, enabling timely referrals. - It addresses the lack of practical oral health assessment tools tailored for non-oral health professionals. - The SHORT tool was developed through expert consensus and is ready for further validation.

ABSTRACTAimTo examine whether the oral microbiota of e‐cigarette users differs from that of never smokers and current smokers.Materials and MethodsPubMed, Scopus and Web of Science were searched on 27 August 2025. Human studies using molecular methods to compare oral microbiota in saliva, subgingival plaque and oral mucosal swabs among e‐cigarette users, never smokers and current smokers were included. Primary outcomes were alpha diversity, beta diversity and differential taxonomic abundance. Risk of bias was assessed using JBI tools and certainty of evidence using GRADE.ResultsTwelve studies were included; most were cross‐sectional and heterogeneous in design, exposure and samples. Alpha diversity findings were inconsistent across samples, whereas beta diversity more consistently indicated distinct microbial communities in e‐cigarette users compared with never smokers and current smokers. Taxonomic differences were heterogeneous and sample‐dependent, with some enrichment of genera such as Veillonella, Leptotrichia, and Fusobacterium compared with never smokers.ConclusionsElectronic cigarette use is associated with sample‐specific oral microbiota differences that partly overlap with, but differ from, those observed in never smokers and current smokers. However, the certainty of evidence is very low due to predominantly cross‐sectional designs and methodological limitations, underscoring the need for longitudinal studies with standardised exposure and protocols.

To determine the future priorities for ectopic pregnancy research. Potential research questions were collated from an initial international survey, a systematic review of clinical practice guidelines, and Cochrane systematic reviews. A rationalized list of confirmed research uncertainties was prioritized in an interim international survey. Prioritized research uncertainties were discussed during a consensus development meeting. Using a formal consensus development method, the modified nominal group technique, diverse stakeholders identified the top 10 research priorities for future ectopic pregnancy research. Healthcare professionals, people with lived experience of ectopic pregnancy, and others were brought together in an open and transparent process using formal consensus methods advocated by the James Lind Alliance. Not applicable. Top 10 research priorities for ectopic pregnancy. The initial survey was completed by 855 participants from 35 countries, and 1,220 potential research questions were submitted. Three clinical practice guidelines and 43 Cochrane systematic reviews identified a further 24 potential research questions. A rationalized list of 49 confirmed research uncertainties was entered into an interim prioritization survey completed by 413 respondents from 20 countries. The top 10 research priorities were identified during a consensus development meeting involving 37 participants from 10 countries. These research priorities are diverse and seek answers to questions regarding prevention, treatment, and the longer-term impact of ectopic pregnancy. We anticipate that the identified research priorities, developed to specifically highlight the most pressing clinical needs as perceived by healthcare professionals, people with lived experience of ectopic pregnancy, and others, will help research funding organizations and researchers to develop their future research agenda.

In the current global conjuncture, marked by protracted wars, genocides, authoritarian populism, imperialism, and renewed colonial ambitions, the production of antagonistic binaries appears particularly acute.From Gaza to Sudan to Ukraine, oppositional logics are repeatedly mobilised to legitimise military aggression and territorial expansion.Such processes of differentiation are far from neutral and are instead deeply entangled with hegemonic and ideological practices (Hall, 1985), involving the production and circulation of (contested) heritage and memory narratives. 1 Narratives of the past often advance claims of ownership over history, geography and suffering that facilitate the framing of the self through differentiation from an imagined "other".This "other" is constantly represented as alien and fundamentally distinct, produced through denial and conferring legitimacy within dominant frameworks.As boundaries between the ingroup and the perceived "other" become increasingly entangled with ideas of threat, survival, and violence, practices of preserving and comparing heritage and memory acquire a distinctly political signification.Contemporary geopolitical conflicts make visible this process as well as the active role played by states and institutions in shaping historical narratives, policing vocabularies, and consequently mobilising categories such as "victimhood" and "perpetration".Although in general terms "perpetration" is used to refer solely to violence that has been committed, in this instance -drawing on the debate within Perpetrator Studies (Knittel and Goldberg 2019) -we use 1 We would like to thank Emilia Bebic for helping with the literature review for this editorial.