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The success of complete dentures is highly dependent on the anatomy of the oral cavity. Several conditions can affect the final denture fit. Disorders of the soft tissues, such as denture hyperplasia, denture stomatitis and mucosal pathology may play a role. There are also difficulties related to the shape of the bone, including excessively large undercuts/bony exostoses, tori, enlarged tuberosities and flabby ridges and other factors, such as xerostomia to be considered. The aim of this article is to help diagnose these conditions and to suggest ways of overcoming the individual problems with which patients present before starting denture construction. CPD/Clinical Relevance: The diagnosis of several oral conditions and their appropriate management may help achieve an optimal outcome when constructing complete dentures.

Objectives This critical review is aimed to investigate the current status of qualitative research in dental implant research and to explore the quality of available information. Material and methods A systematic search was done on the journal databases to identify dental implant research articles that used qualitative methodology during 2006 and 2020. The resulting articles were appraised against the checklist offered by the Critical Appraisal Skills programme (CASP) tool. Also, the theories evolved from the research were reviewed to understand the value of this methodology in dental implant research. Results Twenty-five (25) articles out of the 8,421 original results were identified as using qualitative methodology. The researchers have sought to identify the views of patients about tooth loss, dental implants, and the information they receive from dental professionals, and views of the dentists about dental implant practice. The review found that there were few inconsistencies in the quality of such research especially the qualitative data analysis. Conclusions The quantity of qualitative research in dental implants remains low; however, the quality has improved in the past two decades. Despite these improvements, there is still a lack of research in understanding both patients' and dentists' views on dental implant procedures and management.

Fake news is a recurrent issue in healthcare. Dentistry is not immune to its influence. Patients might find it more convenient to use the Internet to learn more about their oral and dental problems. However, online content may often be misleading and potentially harmful. The advent of COVID-19 has exacerbated the problem. Here, we present simple actions to empower dental professionals against the proliferation of fake news. Understanding the implications of our online activity is important for professionals and our patients.

The edentulous ridge classifications most commonly used have their limitations in treatment planning. They do not provide an indication of the complexities that may occur when constructing a new set of complete dentures. The new classification system suggested in this article helps with improved record-keeping, information exchange between colleagues, and communication between patient and clinician. CPD/Clinical Relevance: The new edentulous ridge classification system links the various edentulous ridge shapes to possible complications that could arise during denture construction.

OBJECTIVES The aim was to evaluate the effectiveness of a pre-clinical training of ceramic crown preparation using the Virtual Educational System for Dentistry. MATERIAL AND METHODS Fifty-seven dental students were recruited to prepare a ceramic crown under the guidance of the Real-time Dental Training and Evaluation System (RDTES) in order to collect pre-learning data. They participated in the online virtual learning course independently on the Virtual Learning Network Platform (VLNP). One week later, the students were invited to complete their post-learning crown preparation with the RDTES. A questionnaire survey explored students' perceived benefits or drawbacks of the virtual educational system. Students were allocated into Group A (n = 15), B (n = 24) and C (n = 18) based on their pre-learning performance. Differences of assessment results amongst different groups were evaluated by ANOVA and Kruskal-Wallis tests. The pre- and post-learning assessment results in all groups were compared using paired t tests or Wilcoxon signed rank tests. RESULTS The error scores for four assessment items (instrument selection, preparation section, preparation reduction, preparation surface and profile) and total score of outcome assessment after the virtual learning were significantly different with those before the virtual learning (P

This paper is concerned with microbubble dynamics in a viscous compressible liquid near a rigid boundary. The compressible effects are modelled using the weakly compressible theory of Wang & Blake (2010, Non-spherical bubble dynamics in a compressible liquid. Part 1. Travelling acoustic wave. J. Fluid Mech., 730, 245–272), since the Mach number associated is small. The viscous effects are approximated using the viscous potential flow theory of Joseph & Wang (2004, The dissipation approximation and viscous potential flow. J. Fluid Mech., 505, 365–377), because the flow field is characterized as being an irrotational flow in the bulk volume but with a thin viscous boundary layer at the bubble surface. Consequently, the phenomenon is modelled using the boundary integral method, in which the compressible and viscous effects are incorporated into the model through including corresponding additional terms in the far field condition and the dynamic boundary condition at the bubble surface, respectively. The numerical results are shown in good agreement with the Keller–Miksis equation, experiments and computations based on the Navier–Stokes equations. The bubble oscillation, topological transform, jet development and penetration through the bubble and the energy of the bubble system are simulated and analysed in terms of the compressible and viscous effects.

INTRODUCTION Increasingly, dental education is using digital strategies to deliver teaching; however, not all of these learning materials are engaging and effective. AIM To evaluate the perception and knowledge retention of undergraduate dental students after using two different digital learning tools: quizzes and PDF. METHODS Thirty-three students from a Dental School in the United Kingdom took part in the research. They received learning material derived from the Prosthodontic (Kennedy classification) or Paediatric dentistry content (Tooth classification). The same content was delivered in two different formats: quiz game (n = 17) and PDF file (n = 16). The PDF file had ten images and their classifications, whilst the quiz had the same images with a question about the classification, along with alternatives (single best answer). RESULTS All students gave similar performances on the knowledge assessment; however, their perception about the learning material differed. Students using quizzes (88%) agreed that they were fun and an interesting way of learning, while only 37.5% had this opinion about PDF material (p = .002). When using quizzes, learners were more motivated and confident. They would frequently recommend quizzes to other colleagues; however, the use of PDF was not suggested as frequently (p = .039). As a learning strategy, 100% of the students using quizzes wanted more of the same to study other dental subjects. This was not the case with the PDF format (p = .005). CONCLUSION Despite quizzes and PDF files resulting in a similar understanding of dental subjects, learners prefer quizzes to supplement their studies. Educators should consider using this interactive digital tool to engage students, instead of PDF files.

Effective biofilm removal from surfaces in the mouth is a clinical challenge. Cavitation bubbles generated around a dental ultrasonic scaler are being investigated as a method to remove biofilms effectively. It is not known how parameters such as surface roughness and instrument distance from biofilm affect the removal. We grew Strepotococcus sanguinis biofilms on coverslips and titanium discs with varying surface roughness (between 0.02-3.15 μm). Experimental studies were carried out for the biofilm removal using high speed imaging and image analysis to calculate the area of biofilm removed at varying ultrasonic scaler standoff distances from the biofilm. We found that surface roughness up to 2 μm does not adversely affect biofilm removal but a surface roughness of 3 μm caused less biofilm removal. The standoff distance also has different effects depending on the surface roughness but overall a distance of 1 mm is just as effective as a distance of 0.5 mm. The results show significant biofilm removal due to an ultrasonic scaler tip operating for only 2s versus 15-60s in previous studies. The technique developed for high speed imaging and image analysis of biofilm removal can be used to investigate physical biofilm disruption from biomaterial surfaces in other fields.

Objectives Dental implants have become a well-publicised treatment modality in dentistry. Implants are generally placed in the private sector by dentists who have undertaken further learning. The continued maintenance of implants falls within the duty of care for the general dental practitioner. The objective of this qualitative study is to investigate the current status of dental implants in general dental practice, and to explore the dentists view on dental implant education at both undergraduate and postgraduate level. Methods In-depth interviews as a qualitative methodology was used in the study. The participants were recruited through theoretical sampling guided by saturation of information. Based on this, 22 general dental practitioners practicing in the UK were interviewed. Transcribed interview data were coded with NVIVO software and then analysed using a thematic framework analysis method. Results General dentists from different educational backgrounds, experience levels participated in the study. They highlighted that the guidelines and protocols when dealing with implants were unclear and expressed their unwillingness to treat patients who had their specialised dental treatment performed elsewhere. Conclusion Expensive dental implant treatment is not being followed up by the general dental practitioner due to a wide range of barriers. Unclear care paths will lead to a likely increase in problems following implant placement. Clinical Significance General Dentists’ views of dental implants in general practice and their expectations from education providers are explored and show the need for improved education.

Purpose The purpose of the present work was to achieve fast and more precise ablation in dentin and enamel by using a commercial femtosecond laser system with high repetition rate, whilst avoiding any collateral irreversible damages in the hard tissue and pulp area. Methods We used fluence of the incident laser pulses which was marginally higher than the ablation threshold for dentin and enamel. The study was based on the hypothesis that femtosecond laser operating with a repetition rate in the range of 100–500 kHz can controllably ablate dental tissue obtaining sufficiently high removal rate whilst avoiding any collateral irreversible damages in the hard tissue and pulp area. Results The ablation yielded the formation of 1 mm3 craters with well-defined precise vertical cavity sides and edges. Advantageous high porosity and numerous interconnected pores were introduced in the ablated zones. Thermal load and hence collateral thermo-mechanical damages were avoided and the crystalline structure of the tooth constituent hydroxyapatite was preserved. Conclusion The ultrafast femtosecond laser used in our work hold the promise of a significant drilling ability without collateral thermomechanical effects. It achieves high processing efficiency, overcomes disadvantages of other laser systems reported and can be used to develop an instrument for cavity preparation based on fast and precise ablation. Our further aim is to exceed the speed of traditional drilling instruments and thus to reduce the treatment time which in turn will bring comfort to the patient.

Fake news is used to spread disinformation on many subjects with the aim of distorting the truth. There has been a rise of fake news stories in dentistry such as homemade whitening products and misinformed information on how to strengthen your teeth. Such stories populate YouTube and other social media. Evidence-based dentistry does not provide all the answers, so patients and health professions readily seek out information that confirms their own views on the subject. There are tools available that may be used to verify the accuracy of such information and help to dispel fake news. The ideal way to deal with the influence of fake news is to empower individuals to publish and create an environment of 'real news'.

It is often the case that good teachers just "intuitively" know how to teach. Whilst that may be true, there is now a greater need to understand the various processes that underpin both the ways in which a curriculum is delivered, and the way in which the students engage with learning; curricula need to be designed to meet the changing needs of our new graduates, providing new, and robust learning opportunities, and be communicated effectively to both staff and students. The aim of this document is to draw together robust and contemporaneous methods of teaching, learning and assessment that help to overcome some of the more traditional barriers within dental undergraduate programmes. The methods have been chosen to map specifically to The Graduating European Dentist, and should be considered in parallel with the benchmarking process that educators and institutions employ locally.

David Antony Walmsley started his anaesthetic career after house jobs with a four year short service commission in the Royal Army Medical Corps, the last two years of which he spent in Rinteln in Germany. Having completed his specialty training he was appointed as only the second full time consultant in anaesthetics at Chelmsford hospitals (now Mid-Essex) in 1965. During his career he served on several local and regional committees including the anaesthetic regional advisory committee, health service complaints procedure, Mid-Essex acute management team, and Mid-Essex …

Aim To investigate the effects of ultrasonic activation file type, lateral canal location and irrigant on the removal of a biofilm-mimicking hydrogel from a fabricated lateral canal. Additionally, the amount of cavitation and streaming was quantified for these parameters. Methodology An intracanal sonochemical dosimetry method was used to quantify the cavitation generated by an IrriSafe 25 mm length, size 25 file inside a root canal model filled with filtered degassed/saturated water or 3 different concentrations of NaOCl. Removal of a hydrogel, demonstrated previously to be an appropriate biofilm mimic, was recorded to measure the lateral canal cleaning rate from two different instruments (IrriSafe 25 mm length, size 25 and K 21 mm length, size 15) activated with a P5 Suprasson (Satelec) at power P8.5 in degassed/saturated water or NaOCl. Removal rates were compared for significant differences using non-parametric Kruskal–Wallis and/or Mann Whitney U tests. Streaming was measured using high-speed particle imaging velocimetry at 250 kfps, analysing both the oscillatory and steady flow inside the lateral canals. Results There was no significant difference in amount of cavitation between tap water and oversaturated water (P=0.538), although more cavitation was observed than in degassed water. The highest cavitation signal was generated with NaOCl solutions (1.0%, 4.5%, 9.0%) (P

Objectives Functionalised silica sub-micron particles are being investigated as a method of delivering antimicrobials and remineralisation agents into dentinal tubules. However, their methods of application are not optimised, resulting in shallow penetration and aggregation. The aim of this study is to investigate the impact of cavitation occurring around ultrasonic scalers for enhancing particle penetration into dentinal tubules. Methods Dentine slices were prepared from premolar teeth. Silica sub-micron particles were prepared in water or acetone. Cavitation from an ultrasonic scaler (Satelec P5 Newtron, Acteon, France) was applied to dentine slices immersed inside the sub-micron particle solutions. Samples were imaged with scanning electron microscopy (SEM) to assess tubule occlusion and particle penetration. Results Qualitative observations of SEM images showed some tubule occlusion. The particles could penetrate inside the tubules up to 60 μm when there was no cavitation and up to ∼180 μm when there was cavitation. Conclusions The cavitation bubbles produced from an ultrasonic scaler may be used to deliver sub-micron particles into dentine. This method has the potential to deliver such particles deeper into the dentinal tubules. Clinical significance Cavitation from a clinical ultrasonic scaler may enhance penetration of sub-micron particles into dentinal tubules. This can aid in the development of novel methods for delivering therapeutic clinical materials for hypersensitivity relief and treatment of dentinal caries.

Bacterial biofilm accumulation is problematic in many areas, leading to biofouling in the marine environment and the food industry, and infections in healthcare. Physical disruption of biofilms has become an important area of research. In dentistry, biofilm removal is essential to maintain health. The aim of this study is to observe biofilm disruption due to cavitation generated by a dental ultrasonic scaler (P5XS, Acteon) using a high speed camera and determine how this is achieved. Streptococcus sanguinis biofilm was grown on Thermanox™ coverslips (Nunc, USA) for 4 days. After fixing and staining with crystal violet, biofilm removal was imaged using a high speed camera (AX200, Photron). An ultrasonic scaler tip (tip 10P) was held 2 mm away from the biofilm and operated for 2 s. Bubble oscillations were observed from high speed image sequences and image analysis was used to track bubble motion and calculate changes in bubble radius and velocity on the surface. The results demonstrate that most of the biofilm disruption occurs through cavitation bubbles contacting the surface within 2 s, whether individually or in cavitation clouds. Cleaning occurs through shape oscillating microbubbles on the surface as well as through fluid flow.

BACKGROUND The Internet has become an established learning tool in dental education where students can access online videos on a range of dental subjects. However, finding reliable peer-reviewed content is not straightforward. AIM To evaluate the video content offered by UK and Republic of Ireland (RoI) Dental Schools on their YouTube channels and public websites. METHODS Free videos offered on UK and RoI Dental schools websites and YouTube channels were watched and set according to its purpose, as educational or non-educational. The number of views, length, category and date of publication were analysed. RESULTS A total of 627 videos offered by dental courses were evaluated. Videos were available on 83% of the websites, but only 9% was educational content. Dental courses YouTube channels received more than 2.3 million views, but less than 5% of the material offered is educational. Instructional videos found on the websites (3.2 min) were shorter than those found on YouTube (8.5 min) (P = .03). The majority of the videos, provided by Universities, were not educational and focused on promoting the dental courses. Most websites have demonstrated a password-protected area where quality content may be offered. CONCLUSION Students wishing to watch instructional videos will find limited educational content provided by UK and RoI dental courses. Therefore, they are likely to access course-related material elsewhere on the Internet that may not be necessarily peer-reviewed.

Introduction Online video sharing platforms are regularly visited by dental students. However, they may be accessing non-peer-reviewed content which is not officially recommended by their dental school's curriculum.Aims To evaluate the reliability of dental education content found on YouTube.Methods A YouTube search for dental procedures content was conducted using the keywords 'restorative dentistry', 'paediatric dentistry', 'orthodontics' and 'oral surgery'. The first ten results of each search were set according to its publisher. The number of views, length, category, retention index and date of publication were analysed.Results Around 70% of the videos were published under education/science categories. These 40 videos received 25 million visitors and showed an average length of 9.22 min (± 8.19). Universities provided only 5% of the content. Older videos had more views per month (p0.05) and a better interaction index (p0.05). Most users preferred the long videos (p0.05) and the interaction index was better for those older videos (p0.01). Short videos had 70% user retention, while ten-minute-long videos had 21%.Conclusions Most of the content found did not match the reliability criteria. Universities should consider how their students use YouTube and look to incorporate their findings into their curriculum. Content length and more recent dental videos will influence student retention and learning.

Highlights • A dental ultrasonic scaler has more cavitation around it in carbonated water. • Increased carbonation increases the amount of cavitation. • More biofilm removal was observed via cavitation in carbonated water., The use of cavitation for improving biofilm cleaning is of great interest. There is no system at present that removes the biofilm from medical implants effectively and specifically from dental implants. Cavitation generated by a vibrating dental ultrasonic scaler tip can clean biomaterials such as dental implants. However, the cleaning process must be significantly accelerated for clinical applications. In this study we investigated whether the cavitation could be increased, by operating the scaler in carbonated water with different CO2 concentrations. The cavitation around an ultrasonic scaler tip was recorded with high speed imaging. Image analysis was used to calculate the area of cavitation. Bacterial biofilm was grown on surfaces and its removal was imaged with a high speed camera using the ultrasonic scaler in still and carbonated water. Cavitation increases significantly with increasing carbonation. Cavitation also started earlier around the tips when they were in carbonated water compared to non-carbonated water. Significantly more biofilm was removed when the scaler was operated in carbonated water. Our results suggest that using carbonated water could significantly increase and accelerate cavitation around ultrasonic scalers in a clinical situation and thus improve biofilm removal from dental implants and other biomaterials.

The objective of this work was to investigate the performance characteristics of a piezoelectric ultrasonic dental scaler using scanning laser vibrometry. The vibration characteristics of three standard piezoelectric tips were assessed with scanning laser vibrometry under various conditions: unconstrained, under a stream of flowing water, in a water tank, as well as subjected to loads to simulate clinical conditions. Subsequently, the tips were used to disrupt an in-vitro biofilm model of dental plaque, developed using a non-pathogenic Gram-negative species of Serratia (NCIMB40259). The laser vibrometry data showed that the oscillation pattern of the ultrasonic tip depends primarily on its shape and design, as well as on the generator power. Thin tips and high power settings induce the highest vibrations. Water irrigation of the tip and loads influence the tip performance by diminishing its vibration, while water volume increases it. Serratia biofilm was disrupted by the cavitation bubbles occurring around the scaler tip. The most effective biofilm removal occurred with the thinner tip. Understanding how the ultrasonic tip oscillates when in use and how it removes dental plaque is essential for gaining more knowledge regarding the cleaning mechanisms of the ultrasonic system. Cavitation may be used to remove plaque and calculus without a mechanical contact between the dental tip and the teeth. Better knowledge would enable dental specialists to understand and improve their techniques during routine cleaning of teeth. It will also lead to improving tip design and to the production of more effective instruments for clinical use.

This paper is concerned with bubble dynamics at a corner formed by two flat rigid boundaries associated with applications in ultrasonic cleaning and cavitation damage. This phenomenon is modeled using the potential flow theory and the boundary integral method. The Green’s function is obtained to satisfy the impenetrable conditions at the rigid boundaries using the method of images with the corner angle α = π/k, where k is a natural number. To evaluate the numerical model, experiments were carried out with a spark-generated bubble in water and recorded using a high-speed camera. The predicted bubble shapes are in excellent agreement with those from the experiments. A jet forms toward the end of the collapse, pointing to the corner when initiated at the bisector of the two walls but pointing to the near wall and inclined to the corner when initiated near one of the two walls. The Kelvin impulse theory predicts the jet direction well. As compared to a bubble near a flat wall, the oscillation period and the jet width increase but the jet velocity decreases. The bubble migrates away from the near wall and the corner during its expansion and moves back toward them during its collapse, but at a much larger speed and amplitude. A velocity stagnation point forms at the start of the collapse, and a high-pressure zone is generated at the base of the jet during the late stages of the collapse, which drives the jet and the bubble toward the near wall and the corner.

Bacterial biofilm accumulation around dental implants is a significant problem leading to peri-implant diseases and implant failure. Cavitation occurring in the cooling water around ultrasonic scaler tips can be used as a novel solution to remove debris without any surface damage. However, current clinically available instruments provide insufficient cavitation around the activated tip surface. To solve this problem a critical understanding of the vibro-acoustic behaviour of the scaler tip and the associated cavitation dynamics is necessary. In this research, we carried out a numerical study for an ultrasound dental scaler with a curved shape tip vibrating in water, using ABAQUS based on the finite element method. We simulated the three-dimensional, nonlinear and transient interaction between the vibration and deformation of the scaler tip, the water flow around the scaler and the cavitation formation and dynamics. The numerical model was well validated with the experiments and there was excellent agreement for displacement at the free end of the scaler. A systematic parametric study has been carried out for the cavitation volume around the scaler tip in terms of the frequency, amplitude and power of the tip vibration. The numerical results indicate that the amount of cavitation around the scaler tip increases with the frequency and amplitude of the vibration. However, if the frequency is far from the natural frequency, the cavitation volume around the free end decreases due to reduced free end vibration amplitude.

A new school of dentistry is an epitome of achievement. The successful institution will oversee the training of dentists and allied dental professionals who will serve and improve the oral health of their communities now and in the future. All dental schools should also aspire to be centers of

Advancements in research and technology are transforming our world. The dental profession is changing too, in the light of scientific discoveries that are advancing biological technology-from new biomaterials to unravelling the genetic make-up of the human being. As health professionals, we embrace a model of continuous quality improvement and lifelong learning. Our pedagogical approach to incorporating the plethora of scientific-technological advancements calls for us to shift our paradigm from emphasis on skill acquisition to knowledge application. The 2017 ADEE/ADEA workshop provided a forum to explore and discuss strategies to ensure faculty, students and, ultimately, patients are best positioned to exploit the opportunities that arise from integrating new technological advances and research outcomes. Participants discussed methods of incorporating the impact of new technologies and research findings into the education of our dental students. This report serves as a signpost of the way forward and how to promote incorporation of research and technology advances and lifelong learning into the dental education curriculum.

Learners are motivated when using games and they have been successfully introduced in many healthcare subjects such as medicine and nursing. The development of games in dentistry has not kept pace with their uptake both as a popular pastime and their implementation in other subjects. Games in the learning space have many advantages. Several scenarios can be gamified in pre-clinical and clinical practice creating an enjoyable learning experience for both undergraduate and postgraduate students. The aim of this article is to enthuse educators on the potential of games and offer practical suggestions on how to implement them in their teaching.

Objectives Sub-micron particles may assist in the delivery of compounds into dentine tubules. The surface interactions of the particles with dentine may prevent them from entering the tubules. The aim of this study is to investigate whether silica particles, treated with surfactants improves dentine tubules occlusion using both artificial and human tooth models Methods Spherical silica particles (size 130–810 nm) bearing an encapsulated ruthenium luminescent complex were coated with the following surfactants: Zonyl ® FSA, Triton ® X-100 and Tween20 ® . The particles were prepared as 0.004% w/v and 0.04% w/v solutions with deionized water and were applied to the surface of; (1) in vitro model of PET ThinCert™ cell culture inserts; (2) 0.1 mm thick sections of human molar teeth. Results Scanning electron and confocal fluorescence microscopy images show that particles without any coating and with TritonX-100 coating had the highest aggregation. Particles with Tween-20 are less aggregated on the surface and show inclusion in the tubules. Particles coated with fluorosurfactant Zonyl show a preference for aggregation at the tubule. With the ThinCert™ membranes high aggregation within the artificial tubules was increased by particle concentration. Conclusions The use of silica sub-micron particles on hard dental tissues is dependent on the modification of the surface chemistry of both the particle and the dentine and the employment of the fluorοsurfactant may improve tubule occlusion. The use of ThinCerts™ membrane is useful in vitro model to mimic dentinal tubules and observe the ability of particles to occlude small channels. Clinical significance The use of silica sub-micron particles on hard dentine tissues is dependent on the modification of the surface coating of the particles. This may influence how particles are incorporated in potential delivery vehicles applied to the dentine surface with the employment of a fluorosurfactant showing promise.

The aim of this study was to understand the opinion of general dental practitioners about the current level of implant education at both undergraduate and postgraduate levels.A questionnaire was sent to the general dental practitioners working in a group of practices in the West Midlands, UK. The completed responses were analysed.Ninety-one out of 101 dentists responded to the questionnaires (95.6%). Sixty-seven (77%) dentists stated that they learnt only theoretical aspects of dental implants during their undergraduate training. The majority of them stated that the training they received was not adequate. In addition, few barriers in dental implant provision by general dentists were also identified in the survey. The main barriers were risk of failures (56.3%), to avoid complications (65.5%) and the cost of learning (51.7%). The results were correlated to the implant competences set by the regulatory organisations such as General Dental Council and Association of Dental Education Europe.The present study confirmed that the current implant education at both undergraduate and postgraduate levels in the UK does not instil confidence to the GDPs to provide and maintain dental implants.

Ultrasonic instruments have been used in dentistry since the 1950's. Initially they were used to cut teeth but very quickly they became established as an ultrasonic scaler which was used to remove deposits from the hard tissues of the tooth. This enabled the soft tissues around the tooth to return to health. The ultrasonic vibrations are generated in a thin metal probe and it is the working tip that is the active component of the instrument. Scanning laser vibrometry has shown that there is much variability in their movement which is related to the shape and cross sectional shape of the probe. The working instrument will also generate cavitation and microstreaming in the associated cooling water. This can be mapped out along the length of the instrument indicating which are the active areas. Ultrasonics has also found use for cleaning often inaccessible or different surfaces including root canal treatment and dental titanium implants. The use of ultrasonics to cut bone during different surgical techniques shows considerable promise. More research is indicated to determine how to maximize the efficiency of such instruments so that they are more clinically effective.

With "The Graduating European Dentist", ADEE provides a new approach that reflects best academic practice for European undergraduate dental education. The new suite of documents sees increased emphasis on important curriculum components such as patient safety, working as a team and patient-centred care. There is also an increased emphasis on teaching excellence, student satisfaction and student preparedness and support. Guidance relating to methods of teaching and learning, and assessment (educational measurement), is also provided. It is anticipated that this new format will further increase accessibility and utility for educators, institutions, societies and regulators, across the sector.

Aim To introduce and characterize a reproducible hydrogel as a suitable biofilm mimic in endodontic research. To monitor and visualize the removal of hydrogel from a simulated lateral canal and isthmus for the following: I) Ultrasonic-Activated Irrigation (UAI) with water, ii) UAI with NaOCl and iii) NaOCl without UAI. Methodology A rheometer was used to characterize the viscoelastic properties and cohesive strength of the hydrogel for suitability as a biofilm mimic. The removal rate of the hydrogel from a simulated lateral canal or isthmus was measured by high-speed imaging operating at frame rates from 50 to 30 000 fps. Results The hydrogel demonstrated viscoelastic behaviour with mechanical properties comparable to real biofilms. UAI enhanced the cleaning effect of NaOCl in isthmi (P < 0.001) and both NaOCl and water in lateral canals (P < 0.001). A greater depth of cleaning was achieved from an isthmus (P = 0.009) than from a lateral canal with UAI and also at a faster rate for the first 20 s. NaOCl without UAI resulted in a greater depth of hydrogel removal from a lateral canal than an isthmus (P < 0.001). The effect of UAI was reduced when stable bubbles were formed and trapped in the lateral canal. Different removal characteristics were observed in the isthmus and the lateral canal, with initial highly unstable behaviour followed by slower viscous removal inside the isthmus. Conclusions The biofilm-mimicking hydrogel is reproducible, homogenous and can be easily applied and modified. Visualization of its removal from lateral canal anatomy provides insights into the cleaning mechanisms of UAI for a biofilm-like material. Initial results showed that UAI improves hydrogel removal from the accessory canal anatomy, but the creation of stable bubbles on the hydrogel–liquid interface may reduce the cleaning rate

Human dentine is a hierarchical mineralized tissue with a two-level composite structure, with tubules being the prominent structural feature at a microlevel, and collagen fibres decorated with hydroxyapatite (HAp) crystallite platelets dominating the nanoscale. Few studies have focused on this two-level structure of human dentine, where the response to mechanical loading is thought to be affected not only by the tubule volume fraction at the microscale, but also by the shape and orientation distribution of mineral crystallites, and their nanoscale spatial arrangement and alignment. In this paper, in situ elastic strain evolution within HAp in dentine subjected to uniaxial compressive loading along both longitudinal and transverse directions was characterized simultaneously by two synchrotron X-ray scattering techniques: small- and wide-angle X-ray scattering (SAXS and WAXS, respectively). WAXS allows the evaluation of the apparent modulus linking the external load to the internal HAp crystallite strain, while the nanoscale HAp distribution and arrangement can be quantified by SAXS. We proposed an improved multiscale Eshelby inclusion model that takes into account the two-level hierarchical structure, and validated it with a multidirectional experimental strain evaluation. The agreement between the simulation and measurement indicates that the multiscale hierarchical model developed here accurately reflects the structural arrangement and mechanical response of human dentine. This study benefits the comprehensive understanding of the mechanical behaviour of hierarchical biomaterials. The knowledge of the mechanical properties related to the hierarchical structure is essential for the understanding and predicting the effects of structural alterations that may occur due to disease or treatment on the performance of dental tissues and their artificial replacements. © 2013 Acta Materialia Inc. Published by Elsevier Ltd.

Introduction The most reliable and frequently applied method for identification of fire victims is comparative dental radiography. Forensic investigators are often confronted with fragmented and isolated remains, frequently removed from their anatomical position. Whilst the heat-induced dimensional and morphological changes in bone have been previously studied, precise data for heat-induced changes of human teeth is still lacking. Objective The aim of this study was to obtain quantitative micro-CT data to evaluate the three-dimensional shrinkage and shape preservation of human teeth to provide an improved understanding on heat-induced alterations of dental tissues. Materials and methods High-resolution micro-CT scans and digital radiographs were carried out on 66 freshly extracted human teeth before and after 30min exposure to temperatures of 400–1000°C. Image analysis was performed using 3D Slicer and Fiji imaging packages. Results The average volumetric shrinkage ranged between 4.78% (at 400°C) and 32.53% (at 1000°C). A major increase in shrinkage occurs between 700°C and 800°C, while no significant statistical difference (ANOVA post-hoc LSD, α Conclusions The results of this micro-CT study add relevant information on shape preservation and allow forensic investigators to account for heat-induced alterations of size, eventually facilitating the odontological identification process in cases where only isolated teeth or dental fragments are present.

Aims To evaluate the quality of clinical record keeping and determine quality of denture cleanliness; record baseline denture cleanliness for 60 patients; introduce denture hygiene instruction (DHI); and then re-assess the patients for improvement and enhanced record keeping. Methods Analysis of patients' denture hygiene instruction record keeping (n = 60) was undertaken retrospectively. The Denture Cleanliness Index (DCI) was utilised to assess denture cleanliness (best score 0, worst score 4). Baseline DCI scores were taken and individual DHI was delivered. After one month, patients were reviewed and scored, with record keeping quality analysed. Results At baseline, 11.7% (n = 7) of patients had DCI scores of ≤2, improving to 93.8% (n = 45) after one month, demonstrating short-term improvement in denture cleanliness. Only 63% (n = 38) of patients had evidence of a record of DHI within their notes at baseline, improving to 100% at recall. Conclusions New patient information leaflet and clinical guidelines on denture hygiene have been written and implemented. The results of this study suggest that this may be a relatively straightforward method to achieve a short-term improvement in denture cleanliness. The implementation of a DCI score is helpful in allowing patients to improve denture hygiene and its wider use is supported.

Objectives: Maintaining oral health around titanium implants is essential. The formation of a biofilm on the titanium surface will influence the continuing success of the implant. These concerns have led to modified ultrasonic scaler instruments that look to reduce implant damage while maximising the cleaning effect. This study aimed to assess the effect of instrumentation, with traditional and modified ultrasonic scalers, on titanium implant surfaces and to correlate this with the oscillations of the instruments. Materials and methods: Two ultrasonic insert designs (metallic TFI-10 and a plastic-tipped implant insert) were selected. Each scaler probe was scanned using a scanning laser vibrometer, under loaded and unloaded conditions, to determine their oscillation characteristics. Loads were applied against a titanium implant (100g and 200 g) for 10 s. The resulting implant surfaces were then scanned using laser profilometry and scanning electron microscopy (SEM). Results: Insert probes oscillated with an elliptical motion with the maximum amplitude at the probe tip. Laser profilometry detected defects in the titanium surface only for the metallic scaler insert. Defect widths at 200 g high power were significantly larger than all other load/power conditions (P

Background: Online discussion boards may enhance critical analysis and reflection, and promote the acquisition of knowledge. Aims: To assess the effectiveness of online discussion board as a pedagogical tool in augmenting face-to-face teaching in dental education. Method: Data were collected from a discussion archive offered through the E-course website of the School of Dentistry, University of Birmingham, UK in 2008. A multi-component metric included; participation, social learning, cognitive processing, role of instructors, and quality of discussion. Messages were coded for 14 variables to evaluate these dimensions. Data were analyzed using content analysis methodology and a complete message was uses as the unit of analysis. Results: There were no significant difference in participation between students and instructors (P

This paper presents the profile and competences for the European Dentist as approved by the General Assembly of the Association for Dental Education in Europe at its annual meeting held in Helsinki in August 2009. A new taskforce was convened to update the previous document published in 2005. The updated document was then sent to all European Dental Schools, ministries of health, national dental associations and dental specialty associations or societies in Europe. The feedback received was used to improve the document. European dental schools are expected to adhere to the profile and the 17 major competences but the supporting competences may vary in detail between schools. The document will be reviewed once again in 5 years time. Feedback to the newly published document is welcomed and all dental educators are encouraged to draw upon the content of the paper to assist them in harmonising the curriculum throughout Europe with the aim of improving the quality of the dental curriculum.

The aim of this study was to evaluate how clinical students reacted to the use of Podcasts for undergraduate teaching. The most popular way of listening to them was on a computer. Students scored highly the subject matter of the Podcasts and used them for learning around the subject, especially during examination time. Podcasts are a valuable vehicle for delivering learning materials to students: offering flexibility but in tune with students' love of downloading materials to use when they wish.

Objective Vascular endothelial growth factor (VEGF) has been implicated in the regulation of dental pulp and dentine repair. Therapeutic ultrasound was shown to be effective for fracture repair. We investigated whether low frequency ultrasound influences the production of VEGF by odontoblast-like cells. Moreover, we examined the direct effects of VEGF on odontoblast-like cell proliferation. Design MDPC-23, an established odontoblast-like cell line, was exposed to increasing intensities of 30 kHz ultrasound using an ultrasonic tip probe. Results After 24 h cell culture, WST-1 analysis of cell viability and number showed a dose-dependent decrease in the number of viable cells with increasing ultrasound power. However, the relative concentration of VEGF as analysed by ELISA and normalised to cell number was significantly increased in the culture supernatants indicating an ultrasound-induced stimulation of odontoblastic VEGF secretion. Analysis of VEGF gene expression by sqRT-PCR revealed the expression of the main VEGF isoforms in the MDPC-23 cells, i.e. VEGF 120 and VEGF 164 as well as to a minor extent VEGF 188 . Low power ultrasound increased gene expression of all VEGF isoforms. Addition of recombinant VEGF to the cell cultures significantly stimulated cell proliferation. Gene expression of the VEGF receptors Flt1/VEGFR1 and KDR/VEGFR2 was detected in the MDPC-23, suggesting the possibility that VEGF may act on the odontoblast-like cells in an autocrine manner. Conclusions Our results indicate that ultrasound promoted VEGF expression and production by odontoblast-like cells and that VEGF may have autocrine effects on these cells. It is proposed that ultrasound may influence odontoblast activity and dentine repair by modulating production of endogenous growth factors in the dentine-pulp complex.

Magnetostrictive materials have been utilized for the production of ultrasonic frequency vibrations for a number of years. This has particularly been the case in laminated nickel-based ultrasonic dental-scaler cleaning systems. In this study, a comparison has been made between the impedances of a number of magnetostrictive stacks of 50 mm×4 mm×∼0.3 mm strips at frequencies in the range of 10–50 kHz in a coil used for the excitation of a stack in a dental-scaler system. The magnetostrictive stacks tested comprised of potential replacement materials for standard nickel ones. The study showed that it was possible to compensate for the inductive ‘imaginary’ components of the impedance through the use of a tuned, series capacitance so that only the ‘real’ resistive component of the impedance remained. This reduced the electrical losses associated with the excitation of the magnetostrictive stacks as a result of the frequency-dependent inductance of the coil system. Consequently, the maximum power transfer from an amplifier to the transducer was increased. Also, the investigation showed how the ‘real’ component of impedance of the different stacks varied with frequency. In a tuned resonant electrical circuit, the resistive component of the impedance, if considered as a loss, would be the lowest that could be achieved with such a magnetic circuit. Consequently, the losses associated with resonant magnetostrictive devices, like dental scalers, can be reduced.

Background: The Objective Structured Clinical Examination (OSCE) is a method of assessing the clinical skills of undergraduates in medicine, dentistry and other health sciences and is employed increasingly in postgraduate education. Aim: To describe the application of the OSCE to the development of Lifelong Learning and Continuing Professional Development (CPD) for General Dental Practitioners (GDPs). Methods: A postgraduate course was designed as an OSCE for GDPs. The OSCE comprised 12 stations covering different aspects of general dentistry. After an introductory seminar outlining the aim of the course, the participants spent 7 min at each station. Each question or task required 10 answers and was designed to highlight areas of weakness or interest and to stimulate further study of the presenting topic. Solutions and answers were provided at each station for self-assessment along with a list of locally presented courses related to that subject. Participants were invited to leave contact details and to make suggestions for future postgraduate courses. The final session consisted of a group discussion and participants were invited to complete an evaluation form to express opinions on the course. Results: The evaluation demonstrated that most candidates found participation in the OSCE stimulated their interest in CPD. The OSCE also highlighted areas of weakness in knowledge of certain clinical procedures. Group discussion confirmed that practitioners found the hands-on component valuable and that they were likely to participate in further OSCEs to enhance their CPD. Suggestions received during the discussion were used to modify the course. Conclusions: The OSCE course fulfilled its aim of assisting practitioners to organise their CPD. The reflective nature of the course was helpful in evaluating clinical knowledge and the unique multidisciplinary style fulfilled its objective in promoting thoughts regarding future study.

To assess cuspal deflection and cervical enamel microleakage with and without an intermediary flowable RBC layer for the incremental restoration of mesio-occluso-distal (MOD) cavities with two resin-based composites (RBCs).Forty sound upper premolar teeth had standardised MOD cavities prepared. Restoration of the teeth involved the placement of the RBCs (Filtek P60 or Filtek Supreme) in eight increments with the appropriate bonding system with and without an intermediary flowable RBC layer (Filtek Flow). Buccal and palatal cusp deflections were recorded post-irradiation using a twin channel deflection measuring gauge. Following restoration, the teeth were thermocycled, immersed in a 0.2% basic fuchsin dye for 24h, sagittally sectioned and examined for cervical enamel microleakage.A significant reduction in cuspal deflection was evident when both RBC materials were used to restore the cavity by employing an intermediary flowable (P0.001) compared with when no intermediary flowable was utilised. No statistically significant differences were identified in microleakage between the teeth restored with Filtek P60 or Filtek Supreme when an intermediary flowable (Filtek Flow) was employed.The results of the current study suggest that there was a benefit to the operator in terms of a reduction in cuspal deflection but not from the maintenance of the synergism of the adhesive bond, namely microleakage at the cervical enamel cavosurface margin, when an intermediate layer of a flowable RBC was used under higher elastic modulus RBCs.

Ultrasonic dental scalers are electronically powered dental cleaning tools which are commonly used by clinicians for dental cleaning. They were developed in the mid 1950s [S.C. Trenter, A.D. Walmsley, G. Landini, J.M. Shippen, Assessment of the ultrasonic dental scaler insert, Med. Eng. Phy. 24 (2002) 139–144]. Ultrasonic scalers are being widely used with few studies on the correct methods and techniques that should be used to obtain their maximum efficiency. Different types of inserts/tips do not show clearly which particular designs are best suited to the task of removing dental calculus to combat periodontal disease. The aim of this study is to begin preliminary investigation on whether the performance of these clinical instruments may be improved if the displacement waveform of the scaler tip could be controlled.

Building on the legacy of historic greenway planning in the U.S., several new initiatives have been taking shape and gaining recognition in the past decade. One is ‘Green Infrastructure’ planning which is a ‘must have’ inter-connected system of green spaces. Another is ‘Smart Conservation’—the counterpoint of another planning initiative that preceded it known as ‘Smart Growth’. This is the establishment of critical green corridors that should be preserved and maintained for predominantly ecological functions, in advance of or in conjunction with new development. ‘New Urbanism’ has focused on bringing order and coherence to escalating ‘Edge Cities’ on the urban fringe, based on walkable, mixed-use towns, villages and neighborhoods with integrated open-space systems. Transit-Oriented Developments (TODs) are transportation plans for accommodating regional growth around clustered ‘pedestrian pockets’ linked by transit systems. Both New Urbanism and TODs have applied similar principles to ‘brown sites’ and declining city neighborhoods. All these initiatives are different aspects of the greenway movement, expressing its many possibilities, enriching its original concepts, enlarging its credibility—if need be—and emphasizing its importance for and relevance to current issues of sustainability and ‘green’ planning and design. The author, a teacher/practitioner, discusses recent U.S. greenway examples at site, metropolitan and regional scales for which he has been the principal planner/designer or a consultant, and compares New Urbanism and TOD methodologies and approaches to established greenway-planning practices and the premises of Smart Conservation.

'Fibrous' or 'flabby' alveolar ridges pose significant problems for the provision of stable and retentive dental prostheses for affected patients. In particular, problems arise during the act of impression taking, when forces cause the mobile denture bearing tissues to become distorted. The purpose of this paper is to review the impression techniques that can be used to optimise the treatment of edentulous patients with 'flabby' alveolar ridges.

The neutral zone technique is an alternative approach for the construction of lower complete dentures. It is most effective for dentures where there is a highly atrophic ridge and a history of denture instability. The technique aims to construct a denture that is shaped by muscle function and is in harmony with the surrounding oral structures. The technique is by no means new but is a valuable one. This paper aims to provide clinicians with the knowledge to use the technique - a list of competencies is included.

Dentistry-related applications for mobile phones are becoming a popular way of accessing information for students, practitioners and patients. The aim of this article is to review the use of mobile technology, such as 'apps', within dentistry. Over time, there has been a change from desktop learning (D-learning) to mobile learning (M-learning) and this has only been possible with the aid of electronic media and the growth of the Internet. In spite of the increase in mobile applications, there is a need for any information to have a strong underlying evidence base. Several good examples of dental applications which take full advantage of this electronic medium are available. However, developers of mobile applications should provide good quality, peer-reviewed evidence to validate their material.

Magnetostrictive materials have been utilized for the production of resonant ultrasonic-frequency vibrations for a number of years. This effect has been utilised in laminated nickel-based ultrasonic dental scaler cleaning systems. Laser vibrometry measurements were undertaken that showed that a typical dental ultrasonic scaler resonated at 29 kHz due to dynamic magnetostriction of the insert's laminated nickel 'stack.' This, in turn, excited insert probe vibrations that are used to remove dental calculus. 3D Femlab™ mechanical finite element models were created to explore the flexural vibration modes associated with the whole insert at the vibration frequency. These models indicated that it was possible to reproduce similar probe vibration mode-shapes to those seen via scanning laser vibrometry measurements. Also, the models indicate that vibrations, useful for dental scaling, can only be achieved if the coupled flexural and longitudinal resonant modes are stimulated at the same drive frequency.

This study assesses, by means of a postal questionnaire, the numbers of general dental practitioners who use clinical photography, and the uses to which this is applied. The questionnaire was distributed to 1000 randomly selected GDPs in Great Britain. A response rate of 76% was achieved. Of the respondents, 36% used clinical photography, with 65% of those using an intra-oral 35 mm camera, 18% a digital camera and 12% an intra-oral digital video camera. Principal uses of clinical photography were patient instruction/motivation (72%), medico-legal reasons (68%), treatment planning (63%), and liaison with laboratory (43%).

Objectives: The aim of this investigation was to assess the effect of loading on ultrasonic scaler tip displacement amplitude, using a scanning laser vibrometer. Material and Methods: Four generators were selected for this investigation including: Cavitron Select (Dentsply), Cavitron SPS (Dentsply), Piezon Master 400 (EMS) and Mini Piezon (EMS). The insert designs used with these generators included the TFI-10 and TFI-3 (with the Dentsply generators) and P-tip (with the EMS generators). The insert tips were contacted against tooth surfaces with loads of 0.25, 0.5 and 1.0 N. The scanning laser vibrometer was then used to scan the vibrating scalers at various generator power settings. Results: The tips generally showed an increase in displacement amplitude with increasing power setting, although this increase was often nonlinear. Displacement amplitudes of like tips were generally found to be significantly different from each other at all loads. For individual inserts, loading caused a significant difference in tip response from the unloaded situation and also between loads. Conclusions: This investigation has demonstrated that there is a high variability associated with dental ultrasonic scaler inserts. Clinicians and researchers should be aware of this variability as it may affect both clinical procedures and future research.