What I wish I'd learned as an orthodontic trainee: an online survey of British Orthodontic Society members concerning postgraduate training experiences.

OBJECTIVE: To survey the opinion of recently qualified and established orthodontists on the perceived value of their training and to identify specific areas which which were considered to be deficient, adequately covered or focussed on excessively. DESIGN: Descriptive cross-sectional survey. SETTING: Online electronic questionnaire. PARTICIPANTS: Members of the British Orthodontic Society (BOS). METHODS: An electronic questionnaire was circulated to members of the BOS focusing on dental education history, and opinions concerning orthodontic teaching generally and specific clinical and non-clinical subjects. Information was also obtained in terms of possible need for improvement, modification or removal of teaching on focused academic and clinical aspects. RESULTS: A total of 217 responses were received from 1080 emailed invitations resulting in a response rate of 20.1%. Respondents were generally satisfied with their training both in relation to theoretical, academic and practical aspects. However, training was regarded as deficient by some respondents in respect of temporary anchorage devices (38%), bonded retainers (6%), experience with lingual appliances (47%), removable aligners (44%), inter-proximal reduction (24%) and adult orthodontics (16%), working with therapists (32%), and NHS contracts (47%) and commissioning (47%). CONCLUSION: The overall satisfaction of BOS members with postgraduate orthodontic training is generally high, although both recently qualified and established practitioners emphasised the need for better exposure to training in specific practical aspects and practice management within the NHS.

Enterococcus faecalis Demonstrates Pathogenicity through Increased Attachment in an Ex Vivo Polymicrobial Pulpal Infection.

This study investigated the host response to a polymicrobial pulpal infection consisting of Streptococcus anginosus and Enterococcus faecalis, bacteria commonly implicated in dental abscesses and endodontic failure, using a validated ex vivo rat tooth model. Tooth slices were inoculated with planktonic cultures of S. anginosus or E. faecalis alone or in coculture at S. anginosus/E. faecalis ratios of 50:50 and 90:10. Attachment was semiquantified by measuring the area covered by fluorescently labeled bacteria. Host response was established by viable histological cell counts, and inflammatory response was measured using reverse transcription-quantitative PCR (RT-qPCR) and immunohistochemistry. A significant reduction in cell viability was observed for single and polymicrobial infections, with no significant differences between infection types (∼2,000 cells/mm2 for infected pulps compared to ∼4,000 cells/mm2 for uninfected pulps). E. faecalis demonstrated significantly higher levels of attachment (6.5%) than S. anginosus alone (2.3%) and mixed-species infections (3.4% for 50:50 and 2.3% for 90:10), with a remarkable affinity for the pulpal vasculature. Infections with E. faecalis demonstrated the greatest increase in tumor necrosis factor alpha (TNF-α) (47.1-fold for E. faecalis, 14.6-fold for S. anginosus, 60.1-fold for 50:50, and 25.0-fold for 90:10) and interleukin 1ß (IL-1ß) expression (54.8-fold for E. faecalis, 8.8-fold for S. anginosus, 54.5-fold for 50:50, and 39.9-fold for 90:10) compared to uninfected samples. Immunohistochemistry confirmed this, with the majority of inflammation localized to the pulpal vasculature and odontoblast regions. Interestingly, E. faecalis supernatant and heat-killed E. faecalis treatments were unable to induce the same inflammatory response, suggesting E. faecalis pathogenicity in pulpitis is linked to its greater ability to attach to the pulpal vasculature.

Mild acids facilitate functional dentin remineralization under thermo-mechanical stimuli.

PURPOSE: To evaluate if mechanical and thermal cycling promote remineralization at the resin-dentin interface after bonding with three different adhesive approaches. METHODS: Dentin surfaces were subjected to three different treatments: demineralization (1) by 37% phosphoric acid followed by application of an etch-and-rinse dentin adhesive Single Bond (Adper Single Bond) (SB); (2) by 0.5 M ethylenediaminetetraacetic acid (EDTA) followed by SB; (3) application of a self-etch dentin adhesive: Clearfil-SEB (Clearfil SE Bond). Bonded interfaces were stored during 24 hours and then submitted for 3 months to: (1) storage at 37ºC, (2) load cycling, (3) thermocycling, and (4) thermo+load cycling. One section was extracted from each tooth, monthly. Resin-dentin interfaces were analyzed by AFM nano-indentation, Raman spectroscopy/cluster analysis and Masson's trichrome staining at 24 hours, 1, 2 and 3 months, to determine remineralization at the interface. RESULTS: Thermo+load cycling promoted the highest biomimetic remineralization at the hybrid layer formed with EDTA+SB and Clearfil-SEB, at the 1 month time point. A narrow mineral-depleted zone was observed after thermo+load cycling with EDTA+ SB, and at those specimens bonded with Clearfil-SEB. Thermo+load cycling remineralized the dentin interface treated with EDTA+SB and Clearfil-SEB, after 1 month of study period, providing bioactivity and maturity of formed minerals. CLINICAL SIGNIFICANCE: In vitro challenging (thermo+load cycling) favors dentin remineralization at the resin-dentin bonded interfaces promoted with mild conditioning acids.

Human In Situ Study of the effect of Bis(2-Methacryloyloxyethyl) Dimethylammonium Bromide Immobilized in Dental Composite on Controlling Mature Cariogenic Biofilm.

Cariogenic oral biofilms cause recurrent dental caries around composite restorations, resulting in unprosperous oral health and expensive restorative treatment. Quaternary ammonium monomers that can be copolymerized with dental resin systems have been explored for the modulation of dental plaque biofilm growth over dental composite surfaces. Here, for the first time, we investigated the effect of bis(2-methacryloyloxyethyl) dimethylammonium bromide (QADM) on human overlying mature oral biofilms grown intra-orally in human participants for 7⁻14 days. Seventeen volunteers wore palatal devices containing composite specimens containing 10% by mass of QADM or a control composite without QADM. After 7 and 14 days, the adherent biofilms were collected to determine bacterial counts via colony-forming unit (CFU) counts. Biofilm viability, chronological changes, and percentage coverage were also determined through live/dead staining. QADM composites caused a significant inhibition of Streptococcus mutans biofilm formation for up to seven days. No difference in the CFU values were found for the 14-day period. Our findings suggest that: (1) QADM composites were successful in inhibiting 1⁻3-day biofilms in the oral environment in vivo; (2) QADM significantly reduced the portion of the S. mutans group; and (3) stronger antibiofilm activity is required for the control of mature long-term cariogenic biofilms. Contact-killing strategies using dental materials aimed at preventing or at least reducing high numbers of cariogenic bacteria seem to be a promising approach in patients at high risk of the recurrence of dental caries around composites.

Effect of Preoperative Occlusal Matrices on the Vickers Microhardness of Composite Disks Polymerized with QTH and LED Lamps.

PURPOSE: This study aimed to assess the reliability of the preoperative occlusal matrix technique in terms of the surface Vickers microhardness (VMH) of the underlying composite restorative material. MATERIALS AND METHODS: Two hundred microhybrid composite cylinders were built up and light-cured in a single-layer step, forming two experimental groups (N = 100) according to their heights (1.5 mm/2 mm). Each group was divided into five subgroups (N = 20) depending on the matrix thickness (no matrix/0.5 mm/1 mm/2 mm/3 mm). Half the specimens per subgroup (N = 10) were randomly polymerized with a quartz-tungsten-halogen (QTH) light-curing unit (LCU). The remaining half were cured using a light-emitting diode lamp. The top and bottom samples' sides were tested for VMH at 1 hour and 24 hours post-curing using a universal VMH machine. A multiple analysis of variance with repeated measurements for the "surface" factor and the Student-Newman-Keuls test were run (α = 0.05). Bottom/top microhardness ratios were compared with the empirically accepted limit (0.8). Surface topography was analyzed under a scanning electron microscope. RESULTS: The thinnest matrices provided the significantly best VMH values. LCU, disc height, and time also contributed to VMH. At 24 hours, 2-mm high discs polymerized with QTH resulted in inadequate microhardness ratios when 1-mm thick to 3-mm thick matrices were used. CONCLUSION: The thinnest matrices are the most recommendable ones. CLINICAL SIGNIFICANCE: The esthetics and occlusal reproducibility achieved with customized occlusal matrices fabricated before cavity preparation have been widely demonstrated. However, their effect on the physical properties of the restorations deserves further investigation. Although more studies are necessary, the thinnest matrices seem to be the most suitable to preserve the composite surface VMH and the curing depth.

Dentin remineralization using a stimuli-responsive engineered small molecule GSK3 antagonists-functionalized adhesive.

OBJECTIVES: Tideglusib has shown great performance in terms of dentin regenerative properties. This study aims to evaluate bonding ability, of demineralized dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TG) (TG-NPs). METHODS: Dentin conditioned surfaces were infiltrated with NPs and TG-NPs. Bonded interfaces were created and stored for 24 h and then submitted to mechanical, chemical and thermal challenging. The resin-dentin interface was evaluated through a doubled dye fluorescent technique and a calcium chelator fluorophore under a confocal laser scanning microscopy, and by field emission scanning electron microscopy. RESULTS: Dentin surfaces treated with TG-NPs and load cycled produced higher bond strength than the rest of the groups. Immersion of dentin specimens treated with undoped-NPs in collagenase solution attained the lowest microtensile bond strength (MTBS) values. Both porosity and nanoleakage decreased when dentin was infiltrated with TG-NPs, that revealed strong signals of xylenol orange stain at both hybrid layer and dentinal tubules. The presence of NPs, in general, inducted the presence of mineralized interfaces after mechanical loading and thermocycling. CONCLUSIONS: Nanoparticles doped with tideglusib promoted the highest dentin bonding efficacy among groups, as they facilitated the maximum bond strength values with creation of mineral deposits at the hybrid layer and dentinal walls. Tideglusib enabled scarce porosity, nanoleakage and advanced sealing among dentin groups. SIGNIFICANCE: Doping hydrophilic polymeric NPs with tideglusib, infiltrated in etched dentin represents a reproducible technique to create reparative dentin at the resin-dentin interface, by inducing therapeutic bioactivity.

Effect of the anti-Alzheimer drug GSK-3ß antagonist on numerical modeling of the energy dissipation through the resin-dentin interface.

OBJECTIVES: The aim of this study was to determine the viscoelastic performance and energy dissipation of conditioned dentin infiltrated with polymeric nanoparticles (NPs) doped with tideglusib (TDg) (TDg-NPs). METHODS: Dentin conditioned surfaces were infiltrated with NPs and TDg-NPs. Bonded interfaces were created, stored for 24 h and submitted to mechanical and thermal challenging. Resin-dentin interfaces were evaluated through nano-DMA/complex-loss-storage moduli-tan delta assessment and atomic force microscopy (AFM) analysis. RESULTS: Dentin infiltrated with NPs and load cycled attained the highest complex modulus at hybrid layer and bottom of hybrid layer. Intertubular dentin treated with undoped NPs showed higher complex modulus than peritubular dentin, after load cycling, provoking energy concentration and breakdown at the interface. After infiltrating with TDg-NPs, complex modulus was similar between peri-intertubular dentin and energy dissipated homogeneously. Tan delta at intertubular dentin was higher than at peritubular dentin, after using TDg-NPs and load cycling. This generated the widest bandwidth of the collagen fibrils and bridge-like mineral structures that, as sight of energy dissipation, fastened active dentin remodeling. TDg-NPs inducted scarce mineralization after thermo-cycling, but these bridging processes limited breakdown zones at the interface. SIGNIFICANCE: TDg-based NPs are then proposed for effective dentin remineralization and tubular seal, from a viscoelastic approach.

Evaluation of preheating methods for bulk-fill thermoviscous composite in non-carious cervical lesions: A 24-month randomized controlled trial.

OBJECTIVE: This 24-month, double-blind, split-mouth randomized equivalence clinical trial compared the clinical performance of a bulk-fill thermoviscous composite resin using two different preheating methods for the restoration of non-carious cervical lesions (NCCLs). MATERIAL AND METHODS: A total of 120 NCCLs were randomized into two groups (n = 60 each). In one group, a bulk-fill thermoviscous composite resin (VisCalor bulk, Voco GmbH) was preheated using a dispenser heater (DH, VisCalor Caps dispenser/warmer), while in the other group, the same resin was preheated with a bench heater (BH, Caps Warmer). In the BH group, the composite underwent preheating at 68 °C using a heating bench for 3 min while in the DH group, the composite was preheated at the same temperature for 30 s using a dispenser heater. Subsequently, the preheated bulk-fill thermoviscous composite resin was directly applied to the NCCLs. The restorations were evaluated at baseline, and after 6, 12, 18, and 24 months of clinical service using the FDI criteria. The total working time was recorded. The study used TOST-P to assess groups equivalence, Kaplan-Meier analysis for retention/fracture rate, log-rank test for secondary outcomes' survival distributions, and paired t-tests for comparing time per clinical step between groups (α = 0.05). RESULTS: After 24 months, 106 restorations were evaluated. Four restorations were lost-two from the DH group and two from the BH group-resulting in similar retention rates for both groups (96.1%, 95% CI 86.8 - 98.9, p > 0.05). The hazard ratio was 0.83 (95% CI 0.26 to 2.72), indicating no significant difference between the groups (p > 0.05). All other FDI parameters were deemed clinically acceptable. However, the total working time for the BH group was significantly longer than that for the DH group (p < 0.001). CONCLUSIONS: Both preheating protocols employed for the bulk-fill thermoviscous composite resin demonstrated high and equivalent survival rates after 24 months, the other FDI parameters were deemed clinically acceptable over the same period. CLINICAL SIGNIFICANCE: Clinicians can choose either method for heating the thermoviscous composite resin for restoration of non-carious cervical lesions, as they do not impact important clinical outcomes after 24 months. The total working time for the bench heater is higher than that for the dispenser heater due to the need for preheating of the bench heater.

'Thermo-mechanical behavior of alternative material combinations for full-arch implant-supported hybrid prostheses with short cantilevers'.

OBJECTIVES: To compare the fracture resistance (FR) of three combinations of materials for full-arch maxillary implant-supported hybrid prostheses (HPs) with short cantilevers (≤ 10 mm). METHODS: Maxillary HPs were fabricated and classified as follows (n = 5 each): Group-1 (CC-A, control): acrylic-resin-veneered Co-Cr frameworks; Group-2 (CF-A): acrylic-resin-veneered carbon-fiber mesostructures; and Group-3 (CF-R): composite-resin-veneered carbon-fiber frames. Specimens were thermal-cycled (5,000 cycles; 5 °C-55 °C; dwell time: 30 s). Vertical loads were applied until failure, first at the 10-mm-long cantilever (LC), and, afterwards, at the anterior region (AR), using a universal testing machine (crosshead speed: 0.05 mm/s). The fracture pattern was assessed by stereomicroscope and SEM. The one-way ANOVA, the Bonferroni, and the independent samples t tests, were run (α= 0.05). RESULTS: At LC, CF-A, and CC-A samples exhibited the highest FR values (p< 0.001), showing no differences to each other. At AR, CC-A specimens recorded the highest FR, followed by CF-A samples (p< 0.001). CF-R HPs displayed the lowest FR at both locations (p< 0.001). The only group with differences between the tested sites was the CC-A, the AR being more resistant (p< 0.001). Most CC-A and CF-A HPs failed cohesively. CF-R prostheses mainly failed adhesively. CONCLUSIONS: Maxillary HPs with short cantilevers (≤ 10 mm) made of Co-Cr or carbon-fiber veneered with acrylic resin demonstrated an adequate mechanical resistance (> 900 N). CLINICAL SIGNIFICANCE: For maxillary HPs with cantilevers up to 10 mm, acrylic-veneered carbon- fiber mesostructures may be recommended, whereas coating carbon-fiber frames with composite resin seems not suitable.

Teaching of posterior composites for the restoration of permanent teeth in undergraduate dental training programmes: Systematic review and meta-analysis.

OBJECTIVES: To systematically assess aspects of teaching of posterior composite restorations (PCRs) in permanent teeth in dental schools. STUDY SELECTION: Quantitative studies reporting on dental schools' teaching regarding the placement of PCRs in permanent teeth. Random-effects meta-analyses and meta-regressions were performed. Risk of bias was assessed based on the Medical Education Research Study Quality Instrument (MERSQI). SOURCES: Electronic databases (MEDLINE via PubMed, EMBASE via Ovid, Web of Science, and Scopus) were searched in January 2023. DATA: Forty sources reporting on 34 studies having surveyed 1,286 dental schools were included. Overall, 92.7% (95%-CI: 88.2-95.5) of dental schools reported to teach PCRs. PCRs in three-surface Class II cavities are taught by 82.0% (95%-CI: 70.4-89.7). The mandatory use of liners in deep cavities is taught by 78.3% (95%-CI: 68.9-85.5), and 44.0% (95%-CI: 34.3-54.2) reported to teach bulk-fill composites. While most posterior restorations placed by students were composites (56.1%; 95%-CI: 46.0-65.8), 94.7% (95%-CI: 86.6-98.0) of dental schools (still) teach posterior amalgam restorations. The proportion of dental schools teaching PCRs in three-surface Class II cavities increased and the mean proportion of PCRs among all posterior restorations increased over time (padj.≤0.003). CONCLUSIONS: The teaching of PCRs in dental schools around the world reflects the increased use of resin composite in clinical practice, with students in countries where dental amalgam continues to be used, placing more posterior composites than restorations of dental amalgam. The teaching of PCRs, which is anticipated to increase, will continue to be refined with further developments in adhesive materials, devices, instrumentation, and techniques. CLINICAL SIGNIFICANCE: Graduating dentists can be expected to be familiar with the use of resin composites for the restoration of posterior teeth.

Dexamethasone and zinc loaded polymeric nanoparticles reinforce and remineralize coronal dentin. A morpho-histological and dynamic-biomechanical study.

OBJECTIVE: To investigate the effect of novel polymeric nanoparticles (NPs) doped with dexamethasone (Dex) on viscoelasticity, crystallinity and ultra-nanostructure of the formed hydroxyapatite after NPs dentin infiltration. METHODS: Undoped-NPs, Dex-doped NPs (Dex-NPs) and zinc-doped-Dex-NPs (Zn-Dex-NPs) were tested at dentin, after 24 h and 21 d. A control group without NPs was included. Coronal dentin surfaces were studied by nano-dynamic mechanical analysis measurements, atomic force microscopy, X-ray diffraction and transmission electron microscopy. Mean and standard deviation were analyzed by ANOVA and Student-Newman-Keuls multiple comparisons (p < 0.05). RESULTS: At 21 d of storage time, both groups doped with Dex exhibited the highest complex, storage and loss moduli among groups. Zn-Dex-NPs and Dex-NPs promoted the highest and lowest tan delta values, respectively. Dex-NPs contributed to increase the fibril diameters of dentin collagen over time. Dentin surfaces treated with Zn-Dex-NPs attained the lowest nano-roughness values, provoked the highest crystallinity, and produced the longest and shortest crystallite and grain size. These new crystals organized with randomly oriented lattices. Dex-NPs induced the highest microstrain. Crystalline and amorphous matter was present in the mineral precipitates of all groups, but Zn and Dex loaded NPs helped to increase crystallinity. SIGNIFICANCE: Dentin treated with Zn-Dex-NPs improved crystallographic and atomic order, providing structural stability, high mechanical performance and tissue maturation. Amorphous content was also present, so high hydroxyapatite solubility, bioactivity and remineralizing activity due to the high ion-rich environment took place in the infiltrated dentin.

Calvaria defect regeneration via human periodontal ligament stem cells and prevascularized scaffolds in athymic rats.

BACKGROUND: Vascularization plays an important role in dental and craniofacial regenerations. Human periodontal ligament stem cells (hPDLSCs) are a promising cell source and, when co-cultured with human umbilical vein endothelial cells (hUVECs), could promote vascularization. The objectives of this study were to develop a novel prevascularized hPDLSC-hUVEC-calcium phosphate construct, and investigate the osteogenic and angiogenic efficacy of this construct with human platelet lysate (hPL) in cranial defects in rats for the first time. METHODS: hPDLSCs and hUVECs were co-cultured on calcium phosphate cement (CPC) scaffolds with hPL. Cell proliferation, angiogenic gene expression, angiogenesis, alkaline phosphatase activity, and cell-synthesized minerals were determined. Bone and vascular regenerations were investigated in rat critical-sized cranial defects in vivo. RESULTS: hPDLSC-hUVEC-CPC-hPL group had 2-fold greater angiogenic expressions and cell-synthesized mineral synthesis than hPDLSC-hUVEC-CPC group (p < 0.05). Microcapillary-like structures were formed on scaffolds in vitro. hPDLSC-hUVEC-CPC-hPL group had more vessels than hPDLSC-hUVEC-CPC group (p < 0.05). In cranial defects in rats, hPDLSC-hUVEC-CPC-hPL group regenerated new bone amount that was 2.1 folds and 4.0 folds, respectively, that of hPDLSC-hUVEC-CPC group and CPC control (p < 0.05). New blood vessel density of hPDLSC-hUVEC-CPC-hPL group was 2 folds and 7.9 folds, respectively, that of hPDLSC-hUVEC-CPC group and CPC control (p < 0.05). CONCLUSION: The hPL pre-culture method is promising to enhance bone regeneration via prevascularized CPC. Novel hPDLSC-hUVEC-CPC-hPL prevascularized construct increased new bone formation and blood vessel density by 4-8 folds over CPC control. CLINICAL SIGNIFICANCE: Novel hPDLSC-hUVEC-hPL-CPC prevascularized construct greatly increased bone and vascular regeneration in vivo and hence is promising for a wide range of craniofacial applications.

Teaching of composite restoration repair in Brazilian dental schools.

OBJECTIVES: The aim was to investigate aspects of the teaching of restoration repair as a minimally invasive alternative to replacing defective direct composite restorations in undergraduate curricula teaching programs in Brazilian dental schools. METHODS: A 14-item validated survey questionnaire was mailed to directors/coordinators of operative/restorative dentistry teachers of Brazilian Dental Schools. Data were collected on demographic characteristics of the teachers and institutions, together with questions on the teaching of the repair of defective resin-based composite restorations as part of the school curriculum; the rationale behind the teaching; the nature of the teaching (preclinical and/or clinical); how techniques were taught, indications for repair, operative techniques, materials used, patient acceptability and expected longevity of completed repairs. RESULTS: Two hundred and twenty-two (94%) directors/ coordinators of dental curricula in Brazil were contacted. One hundred and thirty-one directors/coordinators (59%) replied, providing the e-mail address from the teacher responsible for the operative/restorative dentistry program in their school. Of these, 104 responded to the questionnaire (79% response rate). Ninety-three (89%) of the participating schools reported teaching composite repairs as an alternative to replacing restorations. Of the theoretical content, 43% was taught at preclinical and clinical levels, whereas most practical experience (53%) was acquired at clinical levels. Eighty-eight schools (95%) reported tooth substance preservation being the main reason for teaching repair techniques. All schools that taught repairs reported high patient acceptability. CONCLUSIONS: The teaching of composite restoration repair as an alternative to restoration replacement is established in undergraduate programs in most of the Brazilian dental schools surveyed. CLINICAL SIGNIFICANCE: The reasons for teaching restoration repair in Brazil were found to be quite unanimous among teachers, especially regarding the preservation of tooth structure. Variations were found in the clinical indications for repair, suggesting the need for further investigations. Monitoring repaired restorations should be encouraged and could contribute to future studies.

Successful removable partial dentures.

UNLABELLED: Removable partial dentures (RPDs) remain a mainstay of prosthodontic care for partially dentate patients. Appropriately designed, they can restore masticatory efficiency, improve aesthetics and speech, and help secure overall oral health. However, challenges remain in providing such treatments, including maintaining adequate plaque control, achieving adequate retention, and facilitating patient tolerance. The aim of this paper is to review the successful provision of RPDs. CLINICAL RELEVANCE: Removable partial dentures are a successful form of treatment for replacing missing teeth, and can be successfully provided with appropriate design and fabrication concepts in mind.

A literature review: Entrustable professional activities, an assessment tool for postgraduate dental training?

Assessing when dental trainees are ready to independently undertake clinical procedures at specialist level is critical for dental postgraduate programmes to determine when a trainee is 'work ready', in addition to ensuring patient safety. Entrustable professional activities (EPA) are a novel method of competency-based assessment. An EPA is a unit of professional practice or critical clinical activity identified within dental training programmes, which should be assessed during training, to establish if trainees are ready for independent practice, with a progressive decrease in supervision, based on supervisors' entrustment decisions. This article describes EPAs, entrustment decisions, including entrustment supervision scales and the process recommended to develop EPAs within dental curricula. EPAs have not been formally introduced for assessment within dental education programmes in the United Kingdom, but recent developments have been described in undergraduate dental education globally. Clinical significance: Competency-based assessments need to be continually developed to adapt to rapidly changing population health care and dental needs, to determine when dental trainees are ready for independent clinical practice. Early development of entrustable professional activities for assessment in undergraduate dental programmes has been well received by both trainees and supervisors. Further investigation is required to consider formal development of EPAs within postgraduate dental programmes.

Undergraduate teaching and assessment methods in prosthodontics curriculum: An international Delphi survey.

OBJECTIVES: To achieve consensus amongst an expert panel of prosthodontics/restorative dentistry academics on the best undergraduate teaching and assessments, and to develop recommendations regarding teaching and assessment of undergraduate prosthodontics. METHODS: Semi-structured electronic questionnaires were used to collect data from senior clinical academics involved in the teaching of prosthodontics on three consecutive occasions (Delphi method). The questionnaires asked the experts' opinion on best teaching and assessment methods in the undergraduate prosthodontics curriculum. Invitation emails, with a hyperlink to the Round 1 questionnaire, were sent to 36 international dental academic experts. In later rounds, panellists were invited to consider their previous responses in light of the overall group response in attempt to bring the panel to a consensus. The group response was summarized using simple descriptive statistics, and the target level of consensus for each question was set at ≥ 70%. A response rate of at least 70% between rounds was deemed appropriate to maintain rigour. RESULTS: Twenty-three senior academic experts from eleven countries agreed to participate. Eighteen (representing nine different countries) completed the questionnaires in its entirety (response rate 78.3%). The number of statements that attained consensus agreement was much higher than the number of non-consensus statements-92.6%, 175 statements out of 189 over three iterative rounds. Only 14 statements did not obtain a consensus during this Delphi study. CONCLUSIONS: A total of 175 consensus statements represent the agreement expert views of participated senior academics in prosthodontics from nine different countries and across four continents. These consensus statements could be considered detailed guidelines and recommendations to improve future undergraduates' curriculum in prosthodontics. CLINICAL SIGNIFICANCE: This Delphi study achieved a high consensus among a panel of senior academics in the teaching and assessment of undergraduate prosthodontics. This consensus could help minimise the current international and national divergence in dental schools' prosthodontics curricula, which could benefit future dentists and, subsequently, the patients.

'Role of the modulating factors on the self-perceived OHRQoL of fully dentate subjects and wearers of screw-retained and cement-retained implant-supported FPDs: A cross-sectional study'.

OBJECTIVES: This research aimed to compare the oral health-related quality of life (OHRQoL) between fully dentate subjects and edentulous patients wearing implant-supported fixed partial dentures (i-FPDs). The clinical conditions of both types of restorations were evaluated. METHODS: Participants were assigned to: Group-1 (SR, n = 50): screw-retained i-FPD wearers; Group-2 (CR, n = 50): cement-retained i-FPD wearers; and Group-3 (ND, n = 50): dentate subjects with a healthy natural dentition (controls). Patients answered the OHIP-14sp and QoLIP-10 questionnaires. Data related to sociodemographics, prosthesis features, peri­implant status, complications, and subjective evaluations, were compiled. Potential modulators of the OHRQoL and the i-FPDs' clinical conditions were assessed using non-parametric tests (α= 0.05). RESULTS: ND individuals were the least satisfied (OHIP-14sp; p< 0.001). Both prosthodontic groups reported similar levels of wellbeing, excluding the speaking difficulties, which were lower for SR wearers as shown by both scales (p = 0.001). The most discontented patients (OHIP-14sp) were: women (p = 0.022), under 65 years (p = 0.03), without partner (p< 0.001) and having a crown (p = 0.033). The level of education/schooling also affected the OHIP-14sp scores (p< 0.001). Implant mobility and peri­implantitis were more frequent among CR wearers (p-values= 0.008 and 0.05, respectively). CONCLUSIONS: The OHRQoL of both prosthodontic groups was comparably higher than that of the dentate subjects, who were the most nonconformist. The self-perceived satisfaction was mainly modulated by sociodemographic factors. CLINICAL SIGNIFICANCE: Overall, the retention system did not impact the OHRQoL, prosthetic problems, and subjective evaluations of i-FPD wearers. However, the cementation may increase the risk of peri­implant diseases.

Fracture resistance of cantilevered full-arch implant-supported hybrid prostheses with carbon fiber frameworks after thermal cycling.

OBJECTIVES: This in vitro study aimed to find the best combination of mesostructure and veneering materials for full-arch implant-supported hybrid prostheses (HPs) in terms of the fracture resistance (FR) of their cantilevers. METHODS: Three groups (n = 5 each) of maxillary HPs were fabricated: Group-1 (CC-A, control): Co-Cr frameworks coated with acrylic resin; Group-2 (CF-A): carbon fiber veneered with acrylic resin; and Group-3 (CF-R): carbon fiber coated with composite resin. All specimens were submitted to 5,000 thermal cycles (5 °C - 55 °C, dwell time: 30 s), and subjected to a single cantilever bending test in a universal testing machine (crosshead speed: 0.5 mm/min) until failure. The fracture pattern was assessed using stereo microscope and SEM. The one-way ANOVA and Bonferroni tests were run (α= 0.05). RESULTS: The FR yielded significant differences among the three groups (p< 0.001). CC-A samples reached the highest FR values (p ≤ 0.001), whereas both CF-A and CF-R HPs exhibited the comparably (p = 0.107) lowest FR. CC-A specimens failed cohesively (100%): mostly without chipping (80%). CF-A mesostructures were always broken at the connections of the distal implants. CF-R prostheses often failed adhesively (80%). CONCLUSIONS: The HPs made of Co-Cr veneered with acrylic demonstrated the best mechanical behavior, being the only group whose 13-mm long cantilevers exceeded the clinically acceptable FR of 900 N. The HPs constructed with carbon fiber frameworks showed, additionally, more unfavorable fracture patterns. CLINICAL SIGNIFICANCE: For HPs with cantilevers up to 13 mm, Co-Cr mesostructures coated with acrylic may represent the optimum combination of materials.

Response rates to questionnaire-based studies in the contemporary dental literature: A systematic review.

OBJECTIVES: This systematic review aimed to investigate what is a reasonable response rate for dental questionnaire-based studies in recent literature and to assess the factors that affect the response rates. METHODS: We used MEDLINE/PubMed to search the dental literature of 2021 (January-October). Two reviewers independently assessed studies eligibility and extracted data using standardized electronic extraction form. RESULTS: One hundred and seventy-two studies were eligible, of these a total of 149 response rates were reported from 133 studies, whereas the remaining 39 studies were excluded as they did not report response rates. The median response rate across the included studies was 77% (mean = 70.8%). We found significant negative correlation between the response rate and the actual number of distributed questionnaires (sample size) (r = -0.4127; P < 0.001). We also found an association between the response rate and the area of distribution, e.g., national or international (P = 0.0012). However, a wide variation was observed in the quality of information reported within this review and we did not find clear evidence of association between the response rate and other variables such as questionnaire piloting, number of questions in the questionnaire and the journal impact factor. CONCLUSIONS: The findings of this systematic review confirm the association between the response rate and the sample size, where the response rate increases when the sample size less than 300 participants. In addition, a higher response rate could be achieved when the study conducted within the same institution (e.g., university). SIGNIFICANCE: Questionnaire-based research can provide answers to several questions that could not be answered by other types of research related to the field of dentistry, dental health practitioners and students' attitudes and behaviours and more. Questionnaire-based publications can effectively contribute to dental research; thus, dental journals should consider development of a minimum set of guidelines in the reporting of questionnaire-based manuscripts.

Novel rechargeable nano-calcium phosphate and nano-calcium fluoride resin cements.

OBJECTIVE: In most clinical circumstances, secondary caries at the margin of fixed dental restorations leads to restoration failure and replacement. Accordingly, the objectives of this study were to: (1) develop a novel rechargeable nano-calcium phosphate (NACP) and nano-calcium fluoride (nCaF2) resin-based cement; and (2) investigate their mechanical properties and calcium (Ca), phosphate (P), and fluoride (F) ion release, recharge, and re-release for the first time. METHODS: The cement matrix consisted of pyromellitic glycerol dimethacrylate (PMGDM), ethoxylated bisphenol-A-dimethacrylate (EBPADMA) was denoted PEHB. Four cements were fabricated: (1) PEHB+0%NACP+0%nCaF2 (experimental control); (2) PEHB+25%NACP+0%nCaF2, (3) PEHB+0%NACP+25%nCaF2; (4) PEHB+12.5%NACP+12.5% nCaF2. RelyX luting cement was used as a commercial control. Mechanical properties and long-term Ca, P, and F ion release, recharge, and re-release were evaluated. RESULTS: Adding 25% NACP, 25% nCaF2 and adding both 12.5% NACP and 12.5% nCaF2 to the cement matrix presented a significantly higher shear bond strength, flexural strength compared to the commercial control (p < 0.05) with a comparable outcome with no significant different (p > 0.05) compared to experimental control. The film thickness results of all cement groups met the ISO requirement (<50 µm). The resin cement group with both 12.5% NACP and 12.5% nCaF2 successfully released Ca, P, and F ions at 3.1 ± 0.01, 1.1 ± 0.05, and 0.51±0.01 mmol/L respectively. Moreover, it showed the ability to re-release Ca, P, and F ions at 0.62±0.01, 0.12±0.01, and 0.42±0.01 mmol/L respectively. CONCLUSIONS: The resin cement group with both 12.5% NACP and 12.5% nCaF2 demonstrated the advantages of both types of bio-interactive fillers as it could release a higher level of ions than the resin cement with 25%nCAF2 and exhibited a better rechargeability compared to the resin cement with 25%NACP. CLINICAL SIGNIFICANCE: The ability of this novel resin-based cement to release, recharge, and re-release Ca, P, and F ions could be one of the keys to lengthening the survivability of fixed dental restorations. These features could help to reduce the onset of secondary caries by enhancing the remineralization and preventing the demineralization of tooth structures.