[ZApprO versus ZÄPrO: results of a first comparative study]. / ZApprO versus ZÄPrO: Ergebnisse einer ersten Vergleichsstudie.

BACKGROUND: More than 60 years after the enactment of the first Licensing Regulations for Dentists (ZÄPrO), a new Licensing Regulations for Dentists, the ZApprO, was implemented in 2020. The aims of this study were to evaluate and compare the "Course in Technical Propaedeutics" (TPK) with the course "Dental Propaedeutics with a Focus on Dental Technology" (ZPDT), which are based on different legal foundations. METHODS: The following parameters were compared after completion of the courses: (1) theoretical and practical knowledge, (2) regular department-internal learner evaluation, and (3) special evaluation of learning conditions by the learners and (4) by the instructors. The theoretical and practical exams and the questionnaires were analyzed in terms of their test-statistical characteristics (difficulty, discrimination index, internal consistency). Group comparisons between TPK and ZPDT were conducted using t­tests for independent groups. RESULTS: Significant differences were only detected in the students' evaluation of their learning conditions, with theoretical and practical knowledge transfer being rated lower in the TPK than in the ZPDT. DISCUSSION: The comparable results of the knowledge assessments and the regular learner evaluation, triangulated with the comprehensive learner and instructor evaluation, allowed a broad assessment of both courses. The significant differences identified provide opportunities for optimization of the newly implemented ZPDT course.

A 23-Year Observational Follow-Up Clinical Evaluation of Direct Posterior Composite Restorations.

The purpose of this observational follow-up clinical study was to observe the quality of posterior composite restorations more than 23 years after application. A total of 22 patients, 13 male and 9 female (mean age 66.1 years, range 50-84), with a total of 42 restorations attended the first and second follow-up examinations. The restorations were examined by one operator using modified FDI criteria. Statistical analysis was performed with the Wilcoxon Mann-Whitney U test and Wilcoxon exact matched-pairs test with a significance level of p = 0.05. Bonferroni-Holm with an adjusted significance level of alpha = 0.05 was applied. With the exception of approximal anatomical form, significantly worse scores were seen for six out of seven criteria at the second follow-up evaluation. There was no significant difference in the first and second follow-up evaluations in the grades of the restorations with regard to having been placed in the maxilla or mandible, as well as for one-surface or multiple-surface restorations. The approximal anatomical form showed significantly worse grades at the second follow-up when having been placed in molars. In conclusion, the study results show that significant differences regarding FDI criteria in posterior composite restorations occur after more than 23 years of service. Further studies with extended follow-up time and at regular and short time intervals are recommended.

The effect of new anti-adhesive and antibacterial dental resin filling materials on gingival fibroblasts.

OBJECTIVE: Aim of this study was to evaluate the biocompatibility of four experimental antiadhesive and antibacterial dental filling composites on human gingival fibroblasts (HGFs). METHODS: For these experimental resin composites a delivery system based on novel polymeric hollow beads, loaded with Tego Protect (Aa1), Dimethicone (Aa2), Irgasan (Ab1) and methacrylated polymerizable Irgasan (Ab2) as active agents was used. The cultured HGFs' cell integrity, proliferation, viability, collagen synthesis and cytokine release were measured. For this purpose, human gingival fibroblasts were treated with eluates from all four composites and compared with an experimental standard composite (ST). Eluate extraction times 24 h and 168 h were chosen. RESULTS: Statistical analysis was conducted via a mixed model. Both antibacterial composites reduced proliferation, collagen and cytokine synthesis significantly (p < 0.05), increasing with time of elution. Ab1 did also have a damaging effect on the membrane and on cell viability. SIGNIFICANCE: Overall, it can be concluded that the antiadhesive composites showed clear advantages over the antibacterial composites in terms of biocompatibility. This study also continues to show the potential of the new poly-pore system, as it can be used for a variety of other applications in future composite mixtures.

A multicentric survey to evaluate preclinical education in Endodontology in German-speaking countries.

AIM: To evaluate preclinical education in Endodontology at Austrian, German and Swiss dental schools using an online survey. METHODOLOGY: An online survey divided into nine categories was sent using SurveyMonkey software to 37 dental schools, before the spread of the COVID-19 pandemic. The questionnaire included 50 questions to evaluate preclinical endodontic education, such as faculty-to-student ratios, topics taught and materials used, in preclinical phantom head courses. Seven and 14 days after the first e-mail contact, dental schools received a reminder e-mail. After four and six weeks, the dental schools were contacted by telephone and asked to participate in the online survey. The processing time was eight weeks in total. RESULTS: The response rate was 89%. Preclinical endodontic education at the participating dental schools differs considerably. Theory classes ranged from 1 to 70 h (15 h mean), and practical classes ranged from 3 to 78 h (39 h mean). The faculty-to-student ratio varied between 1:4 and 1:38 (1:15 mean). Forty-five per cent of the dental schools had a specialist in endodontics teaching theory. Several dental microscopes were available for preclinical teaching purposes at 82% of the dental schools. The majority (82%) taught root canal preparation with rotary or reciprocating NiTi instruments. Overall, 85% of the dental schools taught lateral compaction, amongst other methods, for canal filling. CONCLUSION: A substantial divergence amongst the dental schools regarding the time dedicated to theory and practical instruction in Endodontology was reported. However, convergence in the use of root canal treatment techniques and materials was reported.

Adaptation and validation of the Berlin questionnaire of competence in evidence-based dentistry for dental students: a pilot study.

BACKGROUND: The purpose of this pilot study was to create a valid and reliable set of assessment questions for examining Evidence-based Dentistry (EbD) knowledge. For this reason, we adapted and validated for dental students the Berlin Questionnaire (BQ), which assesses Evidence-based Medicine (EbM) abilities. METHODS: The Berlin Questionnaire was validated with medical residents. We adapted it for use in a dentistry setting. An expert panel reviewed the adapted BQ for content validity. A cross-sectional cohort representing four training levels (EbD-novice dental students, EbD-trained dental students, dentists, and EbM-/EbD-expert faculty) completed the questionnaire. A total of 140 participants comprised the validation set. Internal reliability, item difficulty and item discrimination were assessed. Construct validity was assessed by comparing the mean total scores of students to faculty and comparing proportions of students and faculty who passed each item. RESULTS: Among the 133 participants (52 EbD-novice dental students, 53 EbD-trained dental students, 12 dentists, and 16 EbM-/ EbD-expert faculty), a statistically significant (p < 0.001) difference was evident in the total score corresponding to the training level. The total score reliability and psychometric properties of items modified for discipline-specific content were acceptable. Cronbach's alpha was 0.648. CONCLUSION: The adapted Berlin Questionnaire is a reliable and valid instrument to assess competence in Evidence-based Dentistry in dental students. Future research will focus on refining the instrument further.

Cytotoxicity of Self-Etch Versus Etch-and-Rinse Dentin Adhesives: A Screening Study.

Six dentin adhesives were tested in vitro regarding their cytotoxicity on human fibroblasts. The adhesives Hybrid Bond, One-up Bond F Plus, AdheSE, Clearfil SE Bond, Optibond Solo Plus and Syntac were eluted with culture medium as single or sequentially applied adhesive part for 24 h. 75 Petri dishes were produced per group. They were evaluated triangulated, comprising the quantitative evaluation (105 ones) to determine "viable", "dead" and "debris" cells with the use of a cell-counter and the reactivity index was also identified based on the qualitative assessment (420 ones). One-up Bond F Plus, AdheSE and Clearfil SE Bond showed a statistical difference of viable cells to the cell control. For One-up Bond F Plus, statistically, differences compared to hybrid bond and Syntac were also found. All the adhesives except One-up Bond F Plus showed significant differences between single and sequentially applied adhesive part regarding the quantitative evaluation. The test material showed a moderate grade of cytotoxicity. As a result, a statistically significant difference of the cytotoxicity between the self-etch and etch-and-rinse adhesives cannot be demonstrated regarding the qualitative evaluation and the reactivity index, but the differences between sequentially applied and single applied components can be proved.

Students' self-assessment of competencies in the phantom course of operative dentistry.

INTRODUCTION: The aim was to assess the competencies of undergraduate students in their roles of dental expert, scholar, communicator, collaborator, health advocate, manager and professional. MATERIALS AND METHODS: For this retrospective, pseudonymised observational study (pre-/post-testing), students in two cohorts in their first clinical semester in operative dentistry were asked to judge their competencies (1 = very good to 6 = insufficient) with a learning objective catalogue designed at the Goethe University Frankfurt (modelled after the National Competency-Based Learning Objective Catalogue Dentistry), at the beginning and end of their phantom course. In order to relate the students' subjective competency judgements to objective evidence of their skills, at the end of the semester their marks from the summative Objective Structured Practical Examination (OSPE) were compared with the subjective judgement of their exam performance before the final results were known. RESULTS: The reliability of the evaluation sheet was evaluated with Cronbach's alpha 0.98. The students judged their competencies as "sufficient" (4.23 ± 0.51) at the beginning and "satisfactory" (2.82 ± 0.43) at the end. A significant improvement in competencies was observed within all roles. The students' subjective judgement of the exam results (3.66 ± 0.62) was significantly correlated with the actual marks (3.69 ± 0.83) in the OSPE at 0.3547 (P = 0.0015). CONCLUSION: The evaluation instrument showed excellent reliability. The students judged that their competencies significantly increased during the semester. The triangulation with the actual marks in the context of an OSPE demonstrated a significant correlation with the students' exam judgements.

Work shadowing in dental teaching practices: evaluation results of a collaborative study between university and general dental practices.

BACKGROUND: The aim of this study was to investigate the acceptance and assessment of work shadowing carried out by students and dentists in dental practices. Furthermore, the extent to which students perceive an improvement in their specialised, communication and social competencies, was to be examined. METHODS: 61 dental students in their clinical semesters at a German university participated in work shadowing placements at 27 different general dental practices. Before beginning, they received checklists of various competencies that they self-assessed using school grades (from 1 = 'very good', to 6 = 'failed'), which they also repeated after completion. The dentists supplemented this with their external assessments. In addition, the students were requested to fill out a 54-item questionnaire and compose a freely-structured report after the work shadowing; the dentists filled out a questionnaire containing 16 items. The statistical analysis was carried out by means of the Friedman Test, including a post-hoc test (Bonferroni-Holm correction). RESULTS: The analysis showed a significant overall improvement in the students' self-assessed competencies by 0.71* ± 0.43 grades. With an average of 0.33* ± 0.36, the dentists' external assessment proved significantly higher than the self-assessment. The greatest improvements were perceived by the students in the areas of accounting (1.17* ± 0.77), practice organisation (1.05* ± 0.61) and dentist's discussions (0.94* ±0.80) [*p < 0.05]. The students confirmed experiencing an expansion of knowledge, an improvement in their communication skills and indicated a high degree of satisfaction in regard to the dentists (school grade 1.58 ± 0.93). A maximum amount of satisfaction towards the work shadow students was demonstrated by the dentists, and this form of teaching was assessed with a school grade of 1.69 ± 0.89. CONCLUSION: Both students and dental practitioners demonstrated a high level of satisfaction in regard to the work shadowing. The students felt their knowledge had increased, viewed the dentists as motivating role models and acknowledged a significant improvement in their specialised, communication and social competencies. Work shadowing in dental teaching practices presents a sensible addition to academic teaching at a university.

Cross-year peer-assisted learning using the inverted ("flipped") classroom design: A pilot study in dentistry.

BACKGROUND: The inverted classroom model (ICM) represents a special combination of online and attendance learning. The implementation of the didactic concept of "peer-assisted learning" (PAL) within an ICM design has not yet been described in the literature for the field of restorative dentistry. OBJECTIVE: It was the goal of the present study to develop an ICM offering in a cross-year PAL format (ICM-cyPAL), and then introduce and evaluate it. METHOD: The pilot project was conducted at the dental clinic at the Goethe University of Frankfurt/Main, where following its conceptual development and implementation with three consecutive cohorts of students in their first clinical semester (the sixth semester at university) the ICM-cyPAL offering was evaluated. Data on acceptance, tutor effectiveness, group interaction models and learning strategies were collected using an evaluative instrument. RESULTS: 121 students (tutees) participated in three cohorts. The response rate reached 98.3 %. In total, the offering was given an average rating of 6.97±1.93 (from 1 = unsatisfactory to 10 = excellent). As the tutees explained the attention that the tutors employed gave to the group was "just right" (4.65±1.04; where 1 = too controlling and 4 = just right to 7 = left the group on their own too long) and talked "just the right amount" (4.54±0.95; where 1 = too much and 4 = just right to 7 = talked too little). The results for tutor effectiveness reached values between 3.26±0.94 and 3.78±0.87; for the evaluation of group interaction models average values were obtained from 3.41±0.98 to 3.89±0.73 (on a Likert scale of 1 = do not at all agree to 5 = completely agree). Concerning the surveyed learning strategies, the dimensions of "resource management" and "implementation of the learning materials" were given the highest and lowest rankings, respectively. CONCLUSION: The tutees' ratings of the newly developed and implemented ICM-cyPAL offering in the dental context were mainly positive. The thematic orientation of the structured training program needs to be optimized. The offering itself requires both a high degree of organization and solid financial and staffing resources.

[Conception and implementation of a novel E-learning module with EbM learning contents in operative dentistry]. / Konzeption und Implementierung eines neuartigen E-Learning-Moduls mit EbM-Lerninhalten im Fach Zahnerhaltungskunde.

PURPOSE: Computer-assisted learning (CAL) programs are becoming more widely used in medical and dental training. However, the combination of CAL programs and evidence-based education in dentistry has not been described previously. The aim was to determine the acceptance and user-friendliness of a CAL program combined with evidence-based training. METHODS: The didactic concept of the module includes the case-oriented, problem-based embedding of a total of 32 EbM learning assignments, which can be completed interactively and self-determinedly in an interdisciplinary context using focus patients with different diseases. The present study was conducted at the Dental School of the Goethe University in Frankfurt/Main. Data on acceptance and user-friendliness were collected from three consecutive cohorts of 114 dental students attending their first clinical semester. They used the "Toothache Walk-in Clinic: FOCUS" CAL, which can be downloaded via the Internet. The instrument consisted of 64 statements. The first part addressed general information about the user. The second part contained 43 specific statements on the CAL program. These included factors A (handling and technical aspects), B (content and functional range), and C (didactics and suitability for education). Possible responses ranged from 0 to 3 (0 = strongly disagree, 3 = strongly agree). RESULTS: All of the 114 questionnaires distributed were returned (response rate 100%). Most users (90.1%) considered the topics of evidence-based dentistry important for their training. They rated the program by using German school grades, and the overall rating was 2.26 (SD = 0.64). Most students (88.6%) considered the program useful for their clinical training in the treatment of patients. The mean scores for the 43 specific items amounted to 1.90 (factor A, SD = 0.63), 1.55 (factor B, SD = 1.93), and 2.23 (factor C, SD = 0.79). CONCLUSIONS: The CAL program with dental medicine vignettes and learning elements for evidence-based medicine received a primarily positive assessment. Students welcome that EbM contents are offered as part of their dental studies curriculum.

Implementation and sex-specific analysis of students' attitudes toward a longitudinal, gender-specific medical curriculum - a pilot study.

BACKGROUND: Gender medicine has gained importance over the past 20 years. Nevertheless, the scientific findings concerning gender- and sex-specific patient care have not been sufficiently integrated into the education of physicians. It was therefore our aim, against initial resistance in our school, to integrate clinically relevant aspects of gender medicine into the existing medical curriculum. This paper describes the implementation process of a lecture-based interdisciplinary, longitudinal, basic gender curriculum and evaluates students' attitudes in relation to sex and semester level. METHODS: The curriculum encompasses 15 lecture sessions scheduled in years 1 through 5 of the medical curriculum at Ulm University, Germany. Prospectively gathered evaluation data of two cross-sectional analyses of this basic curriculum in the first and fifth semesters are analyzed by sex. RESULTS: More than 80% of the students have registered for this new curriculum. Evaluation data show a predominantly positive (75.5%) student response; however, only about half of those surveyed indicated that they had learned new material or judged the content on gender to be relevant to their practice of medicine. Students at a more advanced semester level (88.2% vs. 55.2%) and male participants more than female participants (36.7% vs. 62.4%) showed lower acceptance. DISCUSSION: It was possible to integrate gender issues into the existing medical student curriculum. Despite the overall positive rating, our evaluation data identified the aspects of rejection and resistance in some students, particularly male and more advanced students. Further studies on the development of student attitudes toward gender issues are needed.

The reliability and predictive validity of a sixth-semester OSPE in conservative dentistry regarding performance on the state examination.

Introduction: The aim of this study was to ascertain whether the testing format of an OSPE (Objective Structured Practical Examination) in conservative dentistry (sixth semester) predicts the scores on the practical section of the state examination (11th semester) in the same subject. Taking general student profiles into consideration (score on the school-leaving exam [Abitur], score on the preliminary exam in dental medicine [Physikum], length of university study, cohorts, and sex), we also investigated if any correlations or differences exist in regard to the total and partial scores on the OSPE and the corresponding state examination. Methods: Within the scope of this longitudinal retrospective study, exam-specific data spanning 11 semesters for dental students (N=223) in Frankfurt am Main were collected and analyzed. Statistical analysis was carried out by calculating Spearman rank correlations, partial correlations, Pearson's correlation coefficients, and multiple regressions (SPSS Statistics 21, IBM Corporation, New York). Results: The results show that the OSPE (Cronbach's α=.87) correlates with level of success on the practical section of the state exam in conservative dentistry (p=.01, r=.17). Length of university study also emerged to correlate significantly with the state exam score (p=.001, r=.23). Together, these two variables contribute significantly to predicting the state exam score (p=.001, R2 =.076). This was seen extensively among female students. It was also discovered that these female students had higher school-leaving exam scores than male students (F=6.09, p=.01, η2 =.027), and that a significant correlation between scores on the Physikum (preliminary exam in dental medicine) and OSPE scores existed only for male students (r=.17, p=.01). Conclusion: This study was able to demonstrate the predictive effect of a clinical OSPE regarding scores achieved on the state exam. Taking the limitations of this study into account, we are able to recommend using the OSPE testing format in the sixth semester during the clinical phase of dental study.

Comparison of the shaping ability of RaCe, FlexMaster, and ProFile nickel-titanium instruments in severely curved root canals.

BACKGROUND: This in vitro study compared the shaping ability of RaCe, FlexMaster, and ProFile rotary nickel-titanium instruments in severely curved root canals of extracted teeth. MATERIAL AND METHODS: Sixty maxillary molars with curvatures ranging from 25° to 65° were embedded in a muffle system and portioned into five horizontal sections (thickness 1.2 mm), starting from the apex. Canals were divided into three groups (n = 20, each) and were prepared with RaCe, FlexMaster, or ProFile rotary nickel-titanium instruments and the TriAuto ZX handpiece using a crown-down preparation technique. We evaluated the difference between pre- and postoperative root canal cross-sections, loss of working length, instrument failure, and preparation time. The root canal area before and after the intervention was determined using an area-measuring software. The data were analyzed statistically using a one-way ANOVA followed by a Kruskal-Wallis multiple-comparison Z-value test. RESULTS: Specimens treated with FlexMaster showed the greatest change from preoperative cross-sections, followed by RaCe and ProFile. The cross-sectional changes induced by RaCe and FlexMaster preparation differed significantly from those produced by ProFile. Loss of working length, instrument failure, and preparation time did not differ significantly between the groups. CONCLUSIONS: Root canal preparation with the three instruments did not lead to any significant alteration of the original root anatomy or working length. Thus, we conclude that RaCe, FlexMaster, and ProFile instruments are of comparable efficiency and usefulness in the preparation of severely curved root canals. Key words:Endodontics, root canal preparation, rotary, extracted teeth, nickel-titanium.

Anatomy meets dentistry! Linking anatomy and clinical practice in the preclinical dental curriculum.

BACKGROUND: Establishing a strong link early on between preclinical coursework and the clinical context is necessary for students to be able to recognize the practical relevance of the curriculum during their preclinical anatomical courses and to transfer knowledge more easily. Our objective was to enhance the clinical relevance of a preclinical anatomy course for second-year medical students of dentistry by implementing an interdisciplinary skills training course on "Palpation of the Head and Neck Muscles" and to measure the learning outcomes. METHODS: For the curricular development of the expanded course module, Kern's 6-step approach was applied including subjective evaluation. We used a peer-teaching format supported by an e-learning application. A randomized control study measured effects of the two components (skills training, e-module) on learning outcomes. Four learning methods were compared: (1) lecture, (2) lecture + e-module, (3) lecture + skills training, (4) lecture + skills training + e-module. An objective structured clinical examination (OSCE) was used to measure and compare learning outcomes. RESULTS: The two-way variance analysis demonstrated that participation in the skills training had a statistically significant effect on the OSCE results (p = 0.0007). Students who participated in the skills training did better (φ 107.4 ± 14.4 points) than students who only attended the lecture (φ 88.8 ± 26.2 points). Students who used the e-module but did not attend the skills training earned a slightly but not significantly higher average number of points (φ 91.8 ± 31.3 points) than those who only attended the lecture. The learning outcomes of the skills training were again significantly increased when the training was combined with the e-module (φ 121.8 ± 21.8 points), thus making it the ideal method for achieving the learning objectives defined in this study. CONCLUSIONS: The "Palpation of the Head and Neck Muscles" interdisciplinary skills training course linking basic anatomical knowledge and clinical skills led to clearly improved learning outcomes for both, anatomical knowledge and clinical skills. The additional use of an e-learning tool (e-module) improved the learning effect.

Study on the Interrater Reliability of an OSPE (Objective Structured Practical Examination) - Subject to the Evaluation Mode in the Phantom Course of Operative Dentistry.

INTRODUCTION: The aim of the study presented here was to evaluate the reliability of an OSPE end-of-semester exam in the phantom course for operative dentistry in Frankfurt am Main taking into consideration different modes of evaluation (examiner's checklist versus instructor's manual) and number of examiners (three versus four). METHODS: In an historic, monocentric, comparative study, two different methods of evaluation were examined in a real end-of-semester setting held in OSPE form (Group I: exclusive use of an examiner's checklist versus Group II: use of an examiner's checklist including an instructor's manual). For the analysis of interrater reliability, the generalisability theory was applied that contains a generalisation of the concept of internal consistency (Cronbach's alpha). RESULTS: The results show that the exclusive use of the examiner's checklist led to higher interrater reliability values than the in-depth instructor's manual used in addition to the list. CONCLUSION: In summary it can be said that the examiner's checklists used in the present study, without the instructor's manual, resulted in the highest interrater reliability in combination with three evaluators within the context of the completed OSPE.

An Introduction to the Inverted/Flipped Classroom Model in Education and Advanced Training in Medicine and in the Healthcare Professions.

In describing the inverted classroom model (ICM), the following paper is meant to provide an introduction to the subject matter and to serve as a practical guide for those wishing to employ its methods in basic and advanced medical training and education. The ICM is a blended-learning method in which a self-directed learning phase (individual phase) precedes the classroom-instruction phase. During the online phase, factual knowledge is imparted that serves as a basis for the classroom phase. The classroom phase should subsequently be used to assimilate and implement the previously gained knowledge. In contrast, traditional course concepts impart factual knowledge in lectures, for example, or in other face-to-face teaching formats and are followed by the students' self-instruction in order to assimilate this knowledge. The goal of the ICM is the shift from passive learning to accelerated learning in order to foster learning at cognitively demanding levels such as analysis, synthesis and evaluation. The concurrent increase in production and use of screencasts and educational videos, the Open Educational Resources "movement" and the widespread use of Massive Open Online Courses (MOOCS) have contributed to the increased dissemination of the inverted-classroom method. The intention of the present paper is to provide an introduction to the subject matter and simultaneously to offer a short overview of important projects and research results in the field of medical education and other health professions. Furthermore, an outline is given of the advantages and disadvantages of the model as well as its potential benefit to the future of medical education and training.

Evaluating differently tutored groups in problem-based learning in a German dental curriculum: a mixed methods study.

BACKGROUND: It is still unclear to what extent the PBL tutor affects learning in PBL-sessions. This mixed-methods study (Part 1 and 2) evaluated the effects of facilitative (f) versus non-facilitative (nf) tutoring roles on knowledge-gain and group functioning in the field of endodontics. METHODS: Part 1 was a quantitative assessment of tutor effectiveness within a prospective, experimental, single-blind, stratified, randomized, two-group intervention study. Participants attended PBL in the context of a hybrid curriculum. A validated questionnaire was used and knowledge assessments were conducted before and after the intervention. External observers rated tutor performance. Part 2 was a qualitative assessment of tutor effectiveness and consisted of semi-structured expert interviews with tutors and focus group discussions with students. RESULTS: Part 1: f tutors obtained significantly higher scores than nf tutors with respect to learning motivation and tutor effectiveness (p ≤ 0.05). nf tuition resulted in a slightly larger knowledge gain (p = 0.08). External observers documented a significantly higher activity among facilitative tutors compared to non-facilitative tutors. Part 2: Tutors found the f role easier although this led to a less autonomous working climate. The students rated f tutoring as positive in all cases. CONCLUSIONS: With respect to PBL-group performance, students felt that groups guided in a non-facilitative fashion exhibited a higher level of independence and autonomy, especially with increasing PBL experience. In addition, students reported that more preparation was necessary for sessions guided by a non-facilitative tutor. Tutors were able to modify their role and influence group processes in a controlled manner. Results are useful for future "Train-the-Teacher" sessions.

Gold Nanoparticle-Mediated Delivery of Molecules into Primary Human Gingival Fibroblasts Using ns-Laser Pulses: A Pilot Study.

Interaction of gold nanoparticles (AuNPs) in the vicinity of cells' membrane with a pulsed laser (λ = 532 nm, τ = 1 ns) leads to perforation of the cell membrane, thereby allowing extracellular molecules to diffuse into the cell. The objective of this study was to develop an experimental setting to deliver molecules into primary human gingival fibroblasts (pHFIB-G) by using ns-laser pulses interacting with AuNPs (study group). To compare the parameters required for manipulation of pHFIB-G with those needed for cell lines, a canine pleomorphic adenoma cell line (ZMTH3) was used (control group). Non-laser-treated cells incubated with AuNPs and the delivery molecules served as negative control. Laser irradiation (up to 35 mJ/cm²) resulted in a significant proportion of manipulated fibroblasts (up to 85%, compared to non-irradiated cells: p < 0.05), while cell viability (97%) was not reduced significantly. pHFIB-G were perforated as efficiently as ZMTH3. No significant decrease of metabolic cell activity was observed up to 72 h after laser treatment. The fibroblasts took up dextrans with molecular weights up to 500 kDa. Interaction of AuNPs and a pulsed laser beam yields a spatially selective technique for manipulation of even primary cells such as pHFIB-G in high throughput.

Quality management of eLearning for medical education: current situation and outlook.

INTRODUCTION: In 2008, the German Council of Science had advised universities to establish a quality management system (QMS) that conforms to international standards. The system was to be implemented within 5 years, i.e., until 2014 at the latest. The aim of the present study was to determine whether a QMS suitable for electronic learning (eLearning) domain of medical education to be used across Germany has meanwhile been identified. METHODS: We approached all medical universities in Germany (n=35), using an anonymous questionnaire (8 domains, 50 items). RESULTS: Our results (response rate 46.3%) indicated very reluctant application of QMS in eLearning and a major information deficit at the various institutions. CONCLUSIONS: Authors conclude that under the limitations of this study there seems to be a considerable need to improve the current knowledge on QMS for eLearning, and that clear guidelines and standards for their implementation should be further defined.

Influence of femtosecond laser treatment on shear bond strength of composite resin bonding to human dentin under simulated pulpal pressure.

This in vitro study evaluated the influence of femtosecond laser (fs-laser)-generated patterns on shear bond strength (SBS) of composite resin bonded to human dentin under simulated pulpal pressure. Laser treatment was used to produce two different patterns on dentin surfaces. Three test groups and a control group without laser treatment under pulpal pressure were investigated. Dentin discs of 800 nm thickness were cut from 60 extracted caries-free human molars. Using a perfusion machine, the discs were exposed to Ringer solution on their basal surfaces. Clearfil SE Bond/Herculite XRV system was used. The samples were stored in distilled water and thermocycled. Bonding failures caused by a test set-up to challenge SBS were analyzed by scanning electron microscope (SEM). An 80 µm-sized cube-shaped pattern caused more cohesive failures in dentin or resin compared with the 160 µm-sized cube-shaped pattern. Weibull statistics demonstrated a significant difference between the two laser patterns, but only the test group with small-sized laser pattern was significantly different from the control group. The Weibull moduli ranged from 4.3 to 9.6 (control group). The 160 µm-sized pattern enhanced the bonding quality and avoided dentin weakening. It was concluded that fs-laser treatment in a 160 µm-sized cube-shaped pattern enabled a simplified bonding procedure by dispensing the primer without affecting SBS, compared with the control group.