Academic Centre For Dentistry Amsterdam Research Articles

Scent of relief: Mastic resin scent recovers salivation in chronic dry mouth patients

BackgroundOlfactory stimulation with mastic resin, derived from the Pistacia lentiscus tree, demonstrated a bona fide sialagogic effect in healthy volunteers [1]. Its main volatile compound, α-pinene, also showed this effect. The current study aimed to validate the effect of mastic resin volatiles in chronic dry mouth patients with confirmed decreased saliva secretion. Methods41 chronic dry mouth patients with decreased unstimulated saliva secretion (<0.25 mL/min) were exposed to mastic resin volatiles as part of the diagnostic routine at the Saliva Clinic of Academic Centre for Dentistry Amsterdam. During their visit, dry-mouth questionnaires were conducted and samples of unstimulated whole saliva, chew-stimulated saliva, acid-stimulated saliva and mastic resin stimulated saliva were collected. Saliva flow rate, spinnbarkeit, pH, ion composition, MUC5B and MUC7 levels in all samples were analyzed. ResultsSalivary flow rates increased by all stimuli when compared to the baseline unstimulated saliva (P<0.001). During olfactory mastic resin stimulation, the salivary spinnbarkeit (P<0.001) and sodium concentration (P<0.01) were increased compared to unstimulated saliva. MUC5B and MUC7 levels were increased during olfactory mastic resin stimulation compared to chew-stimulated saliva (P=0.016 and P<0.001, respectively). Spinnbarkeit correlated positively with MUC5B (R=0.399, P=0.002) and MUC7 levels (R=0.375, P=0.004). Results of dry-mouth questionnaires indicated reduced posterior palate dryness shortly after olfactory mastic resin stimulation (P=0.04). ConclusionsOlfactory mastic resin stimulation increased mucous saliva secretion and reduced posterior palate dryness in a group of chronic dry mouth patients. These findings, validated in patients, underscore mastic resin scent as a beneficial and non-invasive sialagogic treatment for clinical applications.

Patient adherence in orthodontics: a protocol for a scoping review

BackgroundPatient adherence is a key factor in achieving orthodontic success. While in recent years there have been changes in orthodontic healthcare, no recent comprehensive reviews regarding adherence in orthodontics are available. Therefore, the aim of this planned scoping review is to systematically map the available literature regarding patient adherence in orthodontics to identify factors associated with patient adherence and to investigate if there are knowledge gaps in the available literature.Methods/designThis protocol was drafted according to guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analysis Protocols (PRISMA-P) statement and the PRISMA extension for Scoping Reviews (PRISMA-ScR). For the methods Arksey and O’Malley’s framework and the Reviewer’s Manual of the Joanna Briggs Institute for conducting scoping reviews were consulted. The inclusion criteria for this scoping review are studies of all designs assessing any form of adherence in orthodontics, published in English from 2006 onwards. The exclusion criteria are studies investigating adherence in the following patients: those with an intellectual or physical disability that could affect their ability to coincide with their therapist’s recommendations and advice, those with oral cleft and craniofacial conditions, and those solely treated for obstructive sleep apnoea. Case reports and studies published in non peer reviewed journals will also be excluded. The following electronic databases will be searched: Embase, PubMed, and Web of Science Core Collection. The following key terms will be used in the search strategies: ‘treatment adherence and compliance’, and ‘orthodontics’. Multiple reviewers will independently screen the results and perform the data charting process. A narrative description will be provided for the analysis of the included studies. The results will be categorized into multiple topics based on recommendations by previous studies into patient adherence. Identified knowledge gaps will be reported and recommendations for future research will be suggested.DiscussionNo systematic review has previously assessed this exact topic. Because of the broad-spectrum research questions and the expected widely scattered literature a scoping review approach was chosen over a systematic review approach. The Academic Centre for Dentistry Amsterdam (ACTA) has been conducting research in patient adherence in orthodontics up to 2006 and therefore only studies published from 2006 onwards will be researched in this review. Identifying knowledge gaps and summarizing and disseminating research findings on this topic is important for every dental professional performing orthodontic treatment. This protocol is registered in the Open Science Framework: https://osf.io/ec6qd

Maxillary Arch Dimensions in Children with Unilateral Cleft Lip and Palate Receiving Alveolar Bone Grafting.

To analyse the maxillary arch dimensions of children aged 9 and 12 with unilateral cleft lip and palate (UCLP) who received orthodontic treatment and secondary alveolar bone grafting. This retrospective cohort study was performed on 30 patients with UCLP. All patients were treated at the Cleft Lip and Palate Centre, which is part of the University Medical Centre Amsterdam and Academic Centre for Dentistry Amsterdam, the Netherlands. Children with non-syndromic UCLP who received pre- and postsurgical orthodontics combined with secondary alveolar bone grafting between the ages of 9 and 12 years were included. Maxillary arch dimensions were assessed on 60 digitised dental casts with measurements of the intermolar widths, interpremolar widths, arch perimeters, arch lengths, arch widths, and palatal depths. The results of a paired-samples t-test revealed a statistically significant increase (P < .05) in intermolar width 1, intermolar width 3, interpremolar width 1, arch perimeter, and arch width between the ages of 9 (T0) and 12 (T1). Intermolar width 2 and the palatal depth decreased statistically significantly between T0 and T1. Analysis of maxillary arch dimensions of children with UCLP indicates significant changes between 9 and 12 years of age. This suggests that orthodontic treatment and secondary alveolar bone grafting can be effective in improving maxillary arch dimensions. However, there is a need for collaborative research and data collection in order to provide sensible and evidence-based care to patients with cleft lip and palate.

Normal variation of mandibular asymmetry in children.

To explore the normal variation of asymmetry in mandibles of children in the age group of 1 to 12 years. The study group consisted of 92 cadaveric mandibles of children with a dental age of 1 to 12 years old in possession of ACTA (Academic Centre for Dentistry Amsterdam), Faculty of Dentistry, the Netherlands. 3D models of the mandibles were obtained from CT-scans and hemimandibular volumes of all mandibles were calculated. The condylar height, ramus height, mandibular body length and the gonial angle were bilaterally determined using a novel landmark-based method, and the degree of asymmetry was calculated. No relationship was found between dental age and asymmetry of the studied parameters (P < .05). The highest degree of asymmetry was found in the ramus height, whereas the gonial angle presented the lowest degree of asymmetry. A positive correlation was found between the asymmetry of the hemimandibular volume vs the height of the ramus (P < .05) and the length of the mandibular body (P < .05). An inverse correlation was found between the asymmetry of the ramus height vs the condylar height (P < .05), mandibular body length (P < .05) and gonial angle (P < .05). Mandibular asymmetries in children did occur (9.8% of the included mandibles presented with a relevant overall asymmetry of ≥3%) and were unrelated to age. The different segments of the mandible seem to compensate for each other, in order to maintain a functional equilibrium.

Perceived esthetics and value of clear aligner therapy systems: A survey among dental school instructors and undergraduate students.

To investigate the attractiveness, acceptability, visibility and willingness-to-pay for clear aligner therapy (CAT) systems in first-year and final-year dental students and instructors. A questionnaire designed to collect information regarding esthetic preferences and intentions related to seven CAT systems was handed out to 120 undergraduate students and instructors at the Academic Centre for Dentistry Amsterdam (ACTA). Proportional odds models and population average generalized estimating equation models were used to examine potential association between participant characteristics, esthetic perceptions and CAT systems. Overall, the examined CAT systems received favorable esthetic ratings. Expertise status was significantly associated with willingness-to-pay additionally for CAT, compared to fixed orthodontic appliances. There was no association between sex, previous orthodontic treatment history, satisfaction with own dental appearance and potential interest in treatment and aligner visibility and willingness-to-pay. CAT system was significantly associated with the perceived aligner visibility, acceptability and attractiveness by students and instructors. CAT systems were considered to a great extent attractive and acceptable for future treatment by dental school instructors and students. Willingness-to-pay for CAT systems was significantly associated with expertise status, with instructors appearing more reluctant to pay for CAT.

The change in self-efficacy of novice dentists in Endodontics within the first year following graduation from Aarhus University or the Academic Centre for Dentistry Amsterdam.

AimTo understand whether the self‐efficacy of novice dentists in Endodontics changes within the first year following their graduation, and to reveal factors related to a possible change.MethodologyData were obtained from dental graduates from Aarhus University, Denmark or from the Academic Centre for Dentistry Amsterdam, the Netherlands. The 60 participants filled out the Endodontic General Self‐Efficacy Scale questionnaire close to their graduation (baseline) and 1 year following their graduation (follow‐up). Additionally, data on their experience in Endodontics within the first year following graduation were gathered, as well as data on their work environment, their referral behaviour and the postgraduation education they attended. For comparisons, chi‐square tests, Fisher's exact tests, Mann‐Whitney tests, and t‐tests were used. Referral behaviour and the change in self‐efficacy were studied by multiple regression analyses.ResultsMost participants showed an increase in self‐efficacy after graduation. The increase in self‐efficacy was higher for those whose baseline self‐efficacy was lower, and lower for those whose baseline self‐efficacy was higher. Self‐efficacy increased with experience in performing root canal treatments within the first year following graduation. Participants with higher average self‐efficacy (i.e. mean of baseline and follow‐up self‐efficacy) referred patients for endodontic surgery more often than participants with lower average self‐efficacy did.ConclusionsThe self‐efficacy of novice dentists in Endodontics generally increased within the first year following their graduation. The increase in self‐efficacy was greater for those who had low self‐efficacy at graduation than for those who already had high self‐efficacy. Performing root canal treatments was an important factor in increasing self‐efficacy.

Dental and periodontal disease in patients with inflammatory bowel disease

ObjectivesAlthough bowel symptoms are often predominant, inflammatory bowel disease (IBD) patients can have several oral manifestations. The aim of this study was to investigate the prevalence of dental caries and periodontal disease in patients with Crohn’s disease (CD) and ulcerative colitis (UC) compared to an age and gender-matched control group of patients without IBD.Material and methodsThe DMFT (Decayed, Missing, Filled Teeth) scores and the DPSI (Dutch Periodontal Screening Index) of 229 IBD patients were retrieved from the electronic health record patient database axiUm at the Academic Centre for Dentistry Amsterdam (ACTA) and were compared to the DMFT scores and DPSI from age and gender-matched non-IBD patients from the same database.ResultsThe total DMFT index was significantly higher in the IBD group compared to the control group. When CD and UC were analyzed separately, a statistically significant increased DMFT index was observed in CD patients but not in UC patients. The DPSI did not differ significantly between the IBD and non-IBD groups for each of the sextants. However, in every sextant, IBD patients were more frequently edentulous compared to the control patients.ConclusionCD patients have significantly more dental health problems compared to a control group. Periodontal disease did not differ significantly between IBD and non-IBD groups as determined by the DPSI.Clinical relevanceIt is important that IBD patients and physicians are instructed about the correlation between their disease and oral health problems. Strict oral hygiene and preventive dental care such as more frequent checkups should be emphasized by dental clinicians.

Patients' and parents’ expectations of orthodontic treatment in university settings

The primary aim was to compare patients' and parents' orthodontic treatment expectations at the Eastman Institute for Oral Health, University of Rochester, Rochester, NY (UR) in the United States. Secondary aims were to assess the association between sociodemographic factors and UR participants' expectations; and compare participants' expectations between UR, Academic Centre for Dentistry Amsterdam (ACTA) and King's College Dental Hospital, London, United Kingdom (KC) (previously published data). One hundred and forty participants [70 patients and one of their parents (n=70)] completed a validated questionnaire (10 questions) to measure orthodontic treatment expectations before screening at the Orthodontic Department at UR. Various sociodemographic factors were assessed. The paired t test (for continuous responses) and the Fisher exact test (for categorical responses) were used to compare UR patients' and parents' responses. Two-sample t test and the Fisher exact test were used to compare participants' responses among sociodemographic groups. One-way analysis of variance followed by the Tukey test, and the Fisher exact test were used to compare participants' responses between UR, and ACTA and KC (data collected from previous publications). A multiplicity correction was performed to control the false discovery rate. Patients at UR expected less check-up and diagnosis, and less discussion about treatment at the initial visit, more dietary restrictions, and less improvement in smile esthetics and social confidence with orthodontic treatment than parents. Participants' responses differed by sociodemographic factors at UR and between UR, ACTA, and KC. Expectations of orthodontic treatment differ between patients and their parents, are associated with sociodemographic factors, and vary among United States and European University centers.

Students' learning environment perception and the transition to clinical training in dentistry.

IntroductionThe learning environment (LE) influences students’ behaviour, and predicts academic achievement, satisfaction and success. Measuring students’ perception of the LE provides relevant information for curricular quality assurance. In this study, a LE assessment was used to observe variations in students’ LE perception throughout the curriculum, to illustrate the possible influence that preclinical training (Pt) and clinical training (Ct) have on students’ learning experience.Materials and MethodsAll students in the six‐year undergraduate dental programme (n = 849) at the Academic Centre for Dentistry Amsterdam (ACTA) were approached and divided into Pt and Ct groups according to their training phase in the curriculum. The LE was assessed using the Dundee Ready Educational Environment Measure (DREEM), and the results were evaluated using the Statistical Package for the Social Sciences (SPSS) software for distribution (Kolmogorov‐Smirnov normality test), internal reliability (Cronbach's alpha) and comparative analysis (one‐way ANOVA).ResultsThe questionnaire was completed by 216 (response rate=65%) Pt students and by 379 (response rate=75%) Ct students. With a general DREEM score of 124.3, significantly higher scores were found during Pt (DREEM=133.4) in comparison with the Ct phase of the curriculum (DREEM=119.2). DREEM scores steadily decreased throughout the 6‐year curriculum, with the highest drops in LE perception observed in the second and third years of the programme. Significant differences in all DREEM domains were observed, with lower scores for Ct.ConclusionStudents’ LE perception deteriorates throughout the curriculum, especially within the Pt‐Ct transition, during the second and third years of the programme. An inferior LE perception was observed in every domain of the LE questionnaire within this transition showing a learning experience, which requires an educational intervention. Further research is required to better understand the educational needs of the Pt‐Ct transition at this school.

Association between polysomnographic parameters of sleep bruxism and attrition-type tooth wear.

BackgroundClinically, sleep bruxism is considered to be associated with the presence of tooth wear, but strong evidence is still lacking.ObjectiveTo examine whether an association exists between polysomnographic parameters, recorded from patients with possible sleep bruxism and tooth wear.MethodsSixty‐three possible sleep bruxers (19 males and 44 females, mean ± SD age = 38.5 ± 11.4 years) were recruited among patients attending the Clinic for orofacial pain and dysfunction of the Academic Centre for Dentistry Amsterdam (ACTA). The incisal/occlusal tooth wear was recorded for each tooth clinically, using a 5‐point ordinal scale. Subsequently, all patients underwent an one‐night ambulatory polysomnographic recording, during which the number of bruxism episodes per hour of sleep (Epi/h), the number of bruxism bursts per hour of sleep (Bur/h), and the bruxism time index (BTI) were recorded and analysed. Logistic regression analysis was performed using the presence of tooth wear as the dependent variable, the polysomnographic recordings as independent variables, and corrected for age and gender. The Bur/h and BTI were removed from the analyses due to collinearity with the Epi/h. Additionally, the polysomnographic recordings were also tested for possible association with self‐reported grinding of the teeth during sleep.ResultsNo significant correlation was found between tooth wear and Epi/h (P = 0.381). In addition, the presence of tooth wear was not associated with self‐reported parafunctions.ConclusionClinically measured tooth wear and self‐reported parafunction seem not be related to the polysomnographic parameters of possible sleep bruxism.

Patient-based experiences with the use of an ambulatory electromyographic device for the assessment of masticatory muscle activity during sleep.

BackgroundIt is important to know how easy or difficult it is to use an ambulatory electromyographic (EMG) device for sleep bruxism assessment, and how this might affect its future utilisation.ObjectiveTo explore the experience of individuals using an EMG device that pairs with a smartphone app, in order to detect factors that could facilitate and/or hamper its utilisation in future scientific research.MethodsFifteen adults were recruited in the Orofacial Pain and Dysfunction Clinic of the Academic Centre for Dentistry Amsterdam (ACTA). Overnight recordings were performed in the home setting during one week. Time investment, feelings and thoughts, encountered difficulties and reasons for not using the device were assessed in a diary through open‐ended questions and 5‐point Likert scales. Content analysis of textual data was performed, and descriptives of quantitative data were calculated.ResultsTime investment was low (mean 10.2 minutes in the clinic, and 1.9 minutes per recording at home). Quantitative data showed an overall good experience (median of 4). Qualitative diary data showed that the desire to gain insight into one's masticatory muscle activity formed the main motivation to use the device. Device detachment and difficulty in using the app were the most prominent negative experiences.ConclusionThe EMG device was well accepted for multiple overnight recordings. Curiosity for gaining insight into muscle activity was the most important factor that facilitated its use, and the app addressed this need. Device detachment and difficulties in using the app were the main factors that hampered its use.

Serie: Onderwijs en de tandarts anno 2025. Drie opleidingen tandheelkunde in Nederland: drie soorten tandartsen?

In the context of the series on education and the dentist in 2025, the directors of education and training at the 3 dentistry programmes in the Netherlands were asked about the kind of dentist they are training. If, after all, the head of a dental practice is looking for a new colleague and has 3 candidates, each from a different faculty, what can he expect of each of them and are there differences in the 'kind of dentist' they are? In the spring of 2019, Geerling Langenbach and Corine Visscher of the ACTA (Academic Centre for Dentistry Amsterdam), Nico Creugers and Ohlin Cremers of the Radboud University in Nijmegen and Luc van der Sluis and Berdien Kooistra-Akse of the Rijksuniversiteit Groningen were interviewed one after another by Denise van Diermen, guest editor of the series 'Education and the dentist in 2025'.

Associations between sleep bruxism and (peri-)implant complications: lessons learned from a clinical study

ObjectiveTo report and discuss the lessons learned from the conduct of a clinical study on the associations between sleep bruxism and (peri-)implant complications, the protocol of which has been pre-published.Materials and methodsA single-center, double-blind, prospective cohort study with a 2 year follow-up was performed in the Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands. Eleven adult participants were included, where an inclusion of 98 was planned. Sleep bruxism was assessed by multiple single-channel electromyographic (EMG) recordings. Main outcomes were biological and technical complications. Results of the study are presented alongside with comments on encountered difficulties.ResultsInsufficient participant recruitment and failed EMG recordings were encountered. The small sample size did not allow answering the study’s main aim, and was mainly attributed to the study’s protocol complexity. EMG recording failures were attributed to insufficient quality of the EMG signal and detachments of the electrode.DiscussionThe lessons learned from the conduct of this study can be used to design successful future clinical studies.ConclusionsAdequate participant recruitment, effective EMG recordings, and a careful selection of predictor variables are important ingredients for the successful conduct of a longitudinal clinical study on the association between sleep bruxism and (peri-)implant complications.

Research trends and characteristics of oral lichen planus: A bibliometric study of the top-100 cited articles.

Bibliometric analysis highlights the key topics and research trends which have shaped the understanding and management of a concerned disease. The objective of this study was to identify and characterize the most-cited articles on oral lichen planus (OLP), and highlight the analysis of key topics and research trends. A comprehensive search was performed and identified in the Scopus database from 1907 to 5 March 2019 for the top-100 most-cited articles on OLP. The number of citations of the 100 selected articles varied from 101 to 570, with a mean of 178.7 citations per article. Malignant potential, immunopathogenesis, and topical drug therapy were the top-3 study topics, and the majority of high-quality articles were the research of the 3 topics. Journal of Oral Pathology and Medicine (n = 19) and Oral Surgery Oral Medicine Oral Pathology Oral Radiology (n = 14) were 2 journals with the most articles published. Both van der Waal I. and Scully C. were the most frequently contributing authors (n = 9). United States (n = 27) and Academic Centre for Dentistry Amsterdam (n = 7) was the most contributing country and institution, respectively. Systematic reviews (n = 2), randomized controlled trial (n = 1), cohort studies (n = 17) were study designs with higher evidence level, but the large majority (n = 80) were considered lower level. The results of this first citation analysis of the 100 most cited articles on OLP provide a historical perspective on scientific evolution, and suggest further research trends and clinical practice in the field of OLP.

Self-efficacy of undergraduate dental students in Endodontics within Aarhus and Amsterdam.

AimTo understand whether the self‐efficacy of undergraduates is associated with the extent of the endodontic education they received.MethodologyData were obtained from three undergraduate endodontic programmes in two universities: Aarhus University (AU), Denmark and the Academic Centre for Dentistry Amsterdam (ACTA), the Netherlands. Just before their graduations in 2016 or 2017, students completed a questionnaire that contained the Endodontic General Self‐Efficacy Scale and questions on how they valued the education they received in Endodontics. The information on the number and type of root canal treatments participants had performed on patients was collected from dental clinic management systems. Data were ana‐lysed using non‐parametric tests and multiple regression analyses.ResultsThe median number of treated root canals on patients per student was 5 in the standard programme at ACTA, 10 in AU, and 14.5 in the extended programme at ACTA. Students’ self‐efficacy increased with the number of treated root canals; however, retreatments and root canal treatments in molars were negatively associated with self‐efficacy. All students wanted more experience in performing root canal treatment on patients.ConclusionsThe endodontic self‐efficacy of students from the standard programmes of the two participating universities was comparable. Students’ self‐efficacy was influenced mostly by their clinical experience when performing root canal treatment. It seems that the more root canal treatments students perform on patients, the greater their self‐efficacy is at graduation. However, treating difficult cases (molars and retreatments) might reduce their self‐efficacy.

Series: Education and the dentist in 2025. An interfaculty National Progress Test for Dentistry as future method of testing?

The interuniversity Progress Test in Medicine is a measuring instrumentconsisting of about 200 test items, to measure the development ofmedical students' knowledge during their studies. The Progress Testconsists of 4 tests per academic year. Future versions of the ProgressTest will likely be based on computerised administration of the test. One ofthe main goals of the Progress Test is to counter the so-called 'learningto-the-test' effect. Additional benefits are that students and teachers getdetailed feedback about command of knowledge and where omissions inknowledge or the curriculum exist at multiple institutions. A Progress Test for dental education in the Netherlands can easily be conceived becausethe goals of the Progress Test fit well with the common framework(Raamplan Tandheelkunde) shared among the current three dentalprogrammes. The current 'Overalltoets' (general test) of ACTA (academiccentre for dentistry Amsterdam) could form a foundation for starting aProgress Test for dental education.

Dentists on film: Pearl Harbor

H. S. Brand of the Academic Centre for Dentistry Amsterdam, and movie buff, continues his new series of columns on films featuring dentists with Pearl Harbor (2001), directed by Michael Bay.

Diagnostic accuracy of three screening questions (3Q/TMD) in relation to the DC/TMD in a specialized orofacial pain clinic

Objective: To determine the diagnostic accuracy of three screening questions (3Q/TMD) in relation to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD), in a specialized clinic.Material and methods: Consecutive patients, >18 years, referred with a possible TMD complaint to the Orofacial Pain and Dysfunction clinic, Academic Centre for Dentistry Amsterdam, the Netherlands, were included in the study. All patients (n = 449; mean age 44 years; 72% females), answered the 3Q/TMD and the DC/TMD questionnaire before a DC/TMD examination. The 3Q/TMD constitutes of two questions on weekly pain from the jaw, face and temple region (Q1), and on function (Q2), and one function-related question on weekly catching and/or locking of the jaw (Q3). Q1 and Q2 were evaluated in relation to a DC/TMD pain diagnosis and Q3 in relation to a subgroup of DC/TMD intra-articular diagnosis, referred to as the reference standard.Results: In total, 44% of patients received a pain-related DC/TMD diagnosis and 33% an intra-articular reference DC/TMD diagnosis. Sensitivity for the two pain screening questions was high (0.83–0.94), whereas specificity was low (0.41–0.55). For the function-related question, sensitivity was low (0.48), whereas specificity was high (0.96).Conclusions: In a specialized pain clinic, the two pain questions (Q1, Q2) are positive in most patients with pain-related TMD. Therefore, in case of a positive response, further diagnostic procedures for TMD pain are warranted. For the functional screening question (Q3), a positive response is indicative for an intra-articular DC/TMD diagnosis, while in case of a negative outcome, an intra-articular TMD might still be present.

Influence of Method of Teaching Endodontics on the Self-Efficacy and Self-Perceived Competence of Undergraduate Dental Students.

Objective:This study assessed whether self-efficacy and the self-perceived competence of undergraduate dental students had been influenced by the method of teaching endodontics.Methods:Certain modules of the undergraduate endodontic programme at the Academic Centre for Dentistry Amsterdam (ACTA) including the tutorials, the clinical training and the assessment were revised. The self-efficacy and self-perceived competence close to graduation of an intermediate cohort of 24 students who attended all or some of the former modules or the revised modules were assessed. Additionally, the performance of students in performing root canal treatments was assessed according to predetermined criteria. Data were analysed using Cohen’s Kappa, Cronbach’s Alpha, Mann-Whitney and T-tests.Results:Self-efficacy and the self-perceived competence of students who followed the former modules of clinical training and assessment were similar to those of students who followed the revised modules. The revised module with higher number of tutorials increased students’ self-perceived competence, but did not influence their self-efficacy statistically significantly. Not the entire number, but the number of root canal treatments performed under supervision of endodontists was related with an increase in students’ self-efficacy and self-perceived competence. The performance of students in performing root canal tretaments was not statistically significantly related to their self-efficacy and self-perceived competence.Conclusion:Among the modules and their components assessed in the present study, only the number of tutorials and the number of root canal treatments performed under supervision of endodontists influenced the self-efficacy and the self-perceived competence of students.

Cleaning of used rotary nickel-titanium files in an ultrasonic bath by locally intensified acoustic cavitation.

To compare the pre-sterilization cleaning of rotary Ni-Ti files of different sizes previously used a. exvivo and b. clinically by a washer-disinfector, a regular ultrasonic bath, and the same ultrasonic bath in combination with a recently developed cavitation intensifying method. Two sets of two hundred rotary Ni-Ti files, one previously used exvivo and another one used clinically, were collected from the undergraduate and postgraduate clinics of the Academic Centre for Dentistry Amsterdam (ACTA). The instruments were immersed in an enzymatic solution and subsequently cleaned either by a washer-disinfector, a regular ultrasonic bath combined with a glass beaker, the same bath combined with a beaker lined with two cavitation intensifying sheets or with two standard plastic sheets. The positive control consisted of used files that did not undergo any cleaning and the negative control included new unused files. The instruments were then stained to reveal remaining protein material and scored under a stereoscopic microscope. The results were analysed by nonparametric statistical tests (α=0.05). No significant difference was found between the combination of the ultrasonic bath and the regular glass beaker and the same ultrasonic bath with the beaker lined with the cavitation intensifying sheets. The washer-disinfector left significantly more debris compared to the latter group when clinically used files were evaluated (P≤0.001). The effect of instrument size on cleaning was not consistent. None of the tested methods was able to remove all residual protein material from the files; however, it could be noted that this study did not follow the reprocessing protocol provided by the manufacturer.