Poliklinik für Zahnärztliche Prothetik und Werkstoffkunde

Magnesium and its alloys are highly degradable metals that are potentially useful as biomaterials, especially in orthopaedic and cardiovascular applications. However, the in vivo corrosion has proved to be too high. Because of the complexity of in vivo conditions, a careful study of the corrosion of magnesium in synthetic solutions that simulate the in vivo environment is necessary as a first approach to predict the actual in vivo situation. The aim of this work was to evaluate the influence of the electrolyte composition on the corrosion behavior of magnesium and two Mg-alloys in synthetic biological media. Pure magnesium and its alloys (AZ31 and LAE442) were employed in the experiments. Electrochemical potentiodynamic polarization curves were recorded in sodium chloride and PBS electrolytes with different chloride ion and albumin concentration. Optical and SEM observations complemented by EDX analysis were made. The results showed that magnesium corrosion is localized in chloride- and albumin-containing buffer solutions. They also showed that the chloride concentration and the presence of buffer and protein strongly affect the electrochemical behavior of magnesium and magnesium alloys.

Questionnaires measuring oral health-related quality of life (OHRQoL) need reference values for their interpretation. Population-based norms for a questionnaire allow a comparison of the level of OHRQoL observed for an individual or a group of subjects with the level of that construct in the general population. The aims of this study were to establish normative values for abbreviated instruments of the German version of the Oral Health Impact Profile (OHIP-G). Data of the long OHIP-G (53 items) were collected in a national survey (N=2050, age: 16-79 years). Three short instruments with 5 (OHIP-G5), 14 (OHIP-G14) and 21 items (OHIP-G21) were derived from the long OHIP. Norms were computed for the OHIP-G summary score (simple sum of all item responses). The OHIP-G summary score distribution was described by empirical cumulative distribution functions. Because denture usage was strongly associated with OHIP-G summary scores, percentile-based norms were stratified by this variable. Among subjects without dentures, 50% of the population had OHIP-G5 or OHIP-G14 scores 0 and OHIP-G21 scores < or = 2. Summary scores for the three abbreviated OHIPs were < or = 2, < or = 4, and < or = 7 for subjects with removable dentures and < or = 3, < or = 6, and < or = 8 for subjects with complete dentures. Among subjects without dentures, 90% of the population had < or = 4 OHIP-G5, < or = 11 OHIP-G14, and < or = 16 OHIP-G21 points. For subjects with removable dentures, the figures were < or = 7, < or = 17, and < or = 26 points for OHIP-G5, OHIP-G14 and OHIP-G21, respectively; and for subjects with complete dentures, < or = 10, < or = 25, and < or = 38 points, respectively. The presented norms will provide a frame of reference in future cross-sectional studies in the general population or samples with specific oral conditions when OHRQoL is measured by OHIP-G5, OHIP-G14 or OHIP-G21.

This study deals with a three-point flexure test for the metal-ceramic bond involving geometrically simple specimens (alloy strips partly coated with ceramic) that can be fabricated with reasonable expenditure and sufficient reproducibility. The calculation of the stress distribution in such specimens with the aid of the finite-element method (FEM) is presented. The aim of this numerical analysis is: to investigate the stress distribution in a ceramometallic specimen with dimensions that, in a large number of experiments, have proven to lead to debonding at one end of the ceramic veneer instead of a crack in the middle of the veneer; and to assign a bond strength to the measured critical bending force that takes into account the influence of the Young's modulus of the alloy as well as a possible deviation of the thickness of the metal substrate from the standard value. Bond strength values of a variety of metal-ceramic combinations are demonstrated. These experimental results demonstrate the reproducibility of the test method as well as its sensitivity to diverse parameters. The presented method is proposed as an alternative to another flexure bond test nominated for international standard. In this test ceramometallic strips are bent over a rod to a 90 degrees angle of the specimen ends, subsequently flattened, and the fracture surface visually inspected for adherence of the ceramic to the alloy substrate along the predominant part of the middle third of the specimen. It is clear that such a test can at most deliver qualitative results.

OBJECTIVE: Since the Winter Term 2008/2009 the Medical School of the University of Muenster, Germany, has used standardized patients in the clinical course Psychosomatic Medicine and Psychotherapy with fourth-year undergraduate students performing bio-psycho-social anamnesis on these standardized patients. We wanted to evaluate the influence of the course on the empathy of the students. METHODS: A total of 107 students participated in the standardized patient program during the Winter Term 2009/2010, with 90 (84.1 %) completing the Jefferson Scale of Physician Empathy before and after the course. In addition, we conducted a standard evaluation of the medical faculty. RESULTS: The pre-post comparison revealed a significant increase in empathy (d = 0.331, p = .001). The standard evaluation yielded a high satisfaction among the course participants, though several students did assess the course critically. CONCLUSION: The implementation of a standardized patient program in psychosomatics and psychotherapy proved to be of value, since it increased empathy of the students and received a positive evaluation. To prevent the students from being humiliated, it is of particular importance to implement a gentle and tactful feedback.

Purpose: This analysis focused on periodontal health in shortened dental arches (SDAs). Methods: In a randomized controlled clinical trial, patients with missing molars in one jaw and at least one premolar and canine on both sides were eligible for participation. In the partial removable dental prosthesis (PRDP) group (n = 79), molars were replaced with a precision attachment retained PRDP. In the SDA group (n == 71), the SDA up to the second premolars was either left as is or restored with fixed dental prostheses. Outcome variables were vertical clinical attachment loss (CAL-V), pocket probing depth (PPD), bleeding on probing (BOP) and plaque index (PLI). For CAL-V and PPD, the changes at six measuring points per tooth were analyzed. For BOP and PLI, patient related rates were calculated for each point in time. Statistical methods included linear regression analyses. Results: In the intention-to-treat (ITT) analysis for CAL-V in the study jaw, the 10 year patient related mean changes were 0.66 mm in the PRDP group and −0.13 mm in the SDA group. The resulting mean patient related group difference of 0.79 mm (95% CI: 0.20 mm–1.38 mm) was significant (p = 0.01). There were no significant differences in the ITT analyses for PPD. For BOP and PLI, significant group differences with more favorable results for the SDA group were found. Conclusions: In view of lacking substantial differences for CAL-V and PPD, the overall differences were considered of minor clinical relevance. The results add confirmatory evidence to the shortened dental arch concept and its clinical viability (controlled-trials.com ISRCTN97265367).

BACKGROUND: Playing a wind instrument can be either a reason for overuse or a protecting factor against certain diseases. Some individuals have many findings but low morbidity while others have few findings but high morbidity. This contradictory phenomenon should be researched. OBJECTIVE: The temporomandibular system (TMS) is a functional unit which comprises the mandible, associated muscles and bilateral joints with the temporal bone. The TMS is responsible for the generation of sound when wind instruments are played. Over the long-term and with intensive usage, this causes changes in the musculature and in the temporomandibular joint (TMJ) of wind musicians, often resulting in temporomandibular disorders (TMD). The aim of this study is to examine evidence that TMD constitute an occupational disease in wind musicians. PARTICIPANTS: TMD patients and wind musicians were examined by dental clinical functional analysis. 102 male subjects were divided into three groups: "healthy" individuals, wind musicians, and patients with TMD. METHODS: Dental Examination was carried out based on focused inclusion of the research diagnostic criteria - TMD [1,7]. Findings were evaluated for statistical significance by first transferring data into a digital database [2,15], then generating T-Test und Wilcoxon-Test when non-Gaussian distribution appears and applying the Mann-Whitney rank sum test using Sigmaplot Version 1.1 software (Systat Software Inc, Washington, USA). RESULTS: The evaluation revealed that wind instrument musicians show a high incidence of developing TMD as the researchers found almost 100% morbidity regarding parafunctional habits and preauricular muscle pain of each adult and highly active musician. The result is highly significant (p< 0.001) for protrusion distance of the mandible. CONCLUSIONS: A higher prevalence of functional disorders of the musculoskeletal system has previously been demonstrated in wind musicians. New research results and the typical functions of various wind instruments provide evidence that playing a wind instrument generates occupational risks to the TMS.

The oral health of the population in Germany has improved in recent years; however, older people, especially those with frailty and in need of care, have not benefited adequately from this development. Yet, good oral health can make a relevant contribution to better coping with the challenges of frailty and the need for long-term care. Limited access to dental care, and in some cases reduced cooperation and poorer oral hygiene, increases the risk of caries, periodontal diseases, and loss of teeth as well as leads to a higher prevalence of edentulism in comparison to the general population.This paper provides an overview of the dental situation of older people based on previously published data from the population representative Fifth German Oral Health Study (DMS V), which was collected in 2014. The mean number of missing teeth was 11.1 among 65- to 74-year-olds. Older seniors (75-100 years) with care needs (äSmP) had worse oral health than those without care needs (äSoP). Thus, on average, äSoP had 11.8 teeth, whereas äSmP had only 5.7 teeth. The proportion of edentulous 65-74-year-olds had halved since 1997 to 12.4%. Among the äS, 32.8% were edentulous (äSmP: 53.7%, äSoP: 26.7%). More than 75% of the äSmP had removable prosthetic restorations (äSoP: 51.7%). Against this background, this paper identifies interfaces where an equal opportunity connection of these population groups to a dental care structure could be established. These include acute geriatric hospital wards and the development of more far-reaching concepts in outreach care to improve care for those affected and to facilitate care.

AIM: This study aimed to compare the oral health status of 6-16 year old pupils with mental disability (MD) and psycho-emotional disorders (PED) from Lower Saxony (LS) and Thuringia (TH). METHODS: Oral examination was provided for 571 pupils with MD from TH, 118 students with MD and 80 students with PED from LS. Caries experience, odontogenic infections, fissure sealants and periodontal health were recorded. Data were statistically analysed by linear and binary logistic regression after adjusting for age. RESULTS: Students with PED revealed highest caries prevalence and experience in both dentitions with highest prevalence of odontogenic infections in the primary dentition. In 6-11 year old pupils with MD, there were only minor differences in odontogenic infections between TH and LS. Pupils with PED aged 6-11 years had a more that two-fold higher risk to develop dental caries and odontogenic infections than peers with MD. Care index was higher in pupils with PED compared to those with MD in both dentitions. Pupils with MD from TH were less affected with dental caries and received better care than those from LS. Compared to peers without mental disabilities or disorders, pupils with MD or PED were more affected with dental caries in both dentitions. They revealed a lower care index and less fissure sealants. CONCLUSION: Pupils with MD or PED reveal unsatisfactory oral health status constituting a group with particular high caries risk, while those with PED are most affected by caries and odontogenic infections. The care index is insufficient especially in pupils with MD compared to those with PED or peers without disabilities and indicates disparity in oral health for this vulnerable group.

Zusammenfassung Hintergrund Kraniomandibuläre Dysfunktionen (CMD) können auch im hohen Alter auftreten. Die Prävalenz von CMD-Symptomen bei Senioren wurde bisher nur wenig untersucht. Ziel der Arbeit Ziel dieser Untersuchung war es, die Prävalenz von Symptomen einer CMD bei Senioren nach Befunderhebung mit den Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) zu bestimmen. Dabei sollten die Prävalenzwerte von jüngeren (60 bis 74 Jahren) und älteren (≥ 75 Jahre) Senioren verglichen werden. Material und Methoden Im Rahmen der Interdisziplinären Längsschnittstudie des Erwachsenenalters (ILSE) wurden Probanden nach repräsentativen Gesichtspunkten rekrutiert. Während der vierten Nachverfolgungswelle im Zeitraum von 2014 bis 2016 im Bereich des Studienzentrums Leipzig wurden die Probanden auf das Vorliegen von anamnestischen und klinischen CMD-Symptomen untersucht. Ergebnisse Anamnestische CMD-Symptome bei Senioren ( n = 192) waren v. a. durch Schmerzen im Gesichtsbereich (13,0 %) gekennzeichnet. Das häufigste klinische CMD-Symptom waren Kiefergelenkgeräusche mit einer Prävalenz bis zu 35,5 %. Frauen gaben anamnestisch häufiger Kopfschmerzen/Migräne an. Kiefergelenkgeräusche und eine limitierte Mundöffnung wurden klinisch häufiger bei weiblichen Teilnehmenden beobachtet. Statistisch signifikante Unterschiede zeigten sich bei dem Vergleich von jüngeren und älteren Senioren hinsichtlich der Prävalenz von Kopfschmerzen/Migräne, jedoch nicht bei klinischen Symptomen. Schlussfolgerung Anamnestisch werden Gesichtsschmerzen von 13,0 % der Senioren angegeben. Kiefergelenkgeräusche werden bei jedem dritten Älteren klinisch beobachtet. CMD-Symptome scheinen bei jüngeren und älteren Senioren im ähnlichen Maße ausgeprägt zu sein.

The aim of this study was to analyze and evaluate the oral mucosa and the surface constitution of dental materials to display the characteristics and the behaviour of dental composites concerning the margin fit. Therefore, the gingiva and composite restorations of 45 patients aged 17-69 years were examined with a new digital confocal laser scanning microscope developed in Rostock. The device works in contact with the surface of the examination region using a water immersion objective and a diode laser with a wavelength of 670 nm. As a result of a PMMA-Cap with a thickness of 0.5 mm, we can create images with exact depth information and of very good quality. The epithelium of the gingiva with its cellular and subcellular structures could be observed up to a depth of 200 microm. Also, papillary crests, blood vessels and even the blood flow were visible. An inflammation of the gingiva could be verified because of the existence of inflammatory cells. The enamel and dental restorations could be observed up to a depth of 80 microm and allowed the evaluation of the margin fit. Confocal laser scanning microscopy seems to be suitable for the non-invasive examination of oral mucosa and dental materials in vivo.

The provision of patients with removable partial dentures on all-ceramic primary crowns with electroplated gold secondary parts is described as an alternative worthy of consideration in dental journals, lectures and in further training courses. The mode of operation is based on a precise, frictionless, passive fit between female and male components. To guarantee this even over large spans, intraoral joining of the individual components is necessary. However, this requires a different sequence of the treatment steps. The different procedures (conventional, procedure by Weigl, modified concept) are described in the following article. Clinical considerations, design principles, and special characteristics involved in producing the partial denture are explained.

In order to improve tissue integration, the neck region of dental implants was coated with the biodegradable polymer poly (L-lactide) incorporating tetracycline, ibuprofen and the combination of both drugs using a solvent dip-coating process. Metallographic analysis, light microscopy and electron microscopy were used to detect the thickness range and the surface characteristics of the coatings. Cytotoxicity was evaluated using the tetrazolium colorimetric method with the fibroblast cell line L929. The in vitro drug release was measured in isotonic sodium chloride solution by UV spectroscopy. To explore if drug release is concentration-dependent, the total amount of drug was varied in the coating (20% wt, 30% wt and 40% wt). The results showed a continuous release of the embedded drugs in relevant dosage over a period of 6 months. In contrast to high tetracycline concentrations, high ibuprofen concentrations resulted in a decreased metabolic activity of the L929 fibroblasts.

OBJECTIVES: The success of referral for psychotherapy and the predictors thereof are investigated in dentistry in an outpatient unit for psychosomatics. METHODS: 238 patients were asked in a telephone interview concerning their satisfaction with the consultation as well as any change in their complaints and treatments after their contact with the outpatient unit. RESULTS: 82.3 % of the patients were satisfied with the consultation, and 55.9 % reported an improvement in their complaints. In 76.1 % of the patients psychotherapy was indicated, and 56.7 % showed motivation and were referred to psychotherapy. Thereof, 66.7 % actually began treatment. Introspective capacity and motivation for psychotherapy predicted successful referral. Patients suffering from somatoform disorders were significantly less motivated to begin psychotherapy and showed a tendency toward premature termination of psychotherapy. In patients with anxiety disorders, the reverse was the case. Patients who did not begin psychotherapy changed their dentist significantly more frequently. CONCLUSIONS: The consultation at the outpatient unit can be regarded as successful insofar as four-fifths of the patients were satisfied and two-thirds of those referred actually began psychotherapy, which in turn significantly reduces "dentist shopping."

The discoloration of enamel and dentin often has a lasting negative impact on the esthetic appearance. The current clinical case report illustrates which results can be achieved by supplying a patient with restorations fabricated from translucent tooth-colored materials for a traumatically damaged and discolored anterior tooth. A 20-year-old patient sought dental care due to a severe discrepancy in color and shape of tooth 11. As internal bleaching did not reveal a satisfying esthetic outcome, consequently we decided to supply the tooth with a 360° veneer. For material comparisons, the restorations were fabricated from five different monolithic materials. The preparation was performed following the guidelines for 360° veneers, featuring a circular thickness of 0.9 mm. The selected materials included indirect resin composite (Grandio blocs LT, VOCO), feldspathic ceramic (VITABLOCS Mark II LT, VITA Zahnfabrik), leucite-reinforced glass ceramic (IPS Empress CAD LT, Ivoclar Vivadent), lithium disilicate ceramic (IPS e.max CAD LT, Ivoclar Vivadent), and zirconia with 5 mol% yttrium oxide (VITA YZ XT Multicolor LT, VITA Zahnfabrik). The materials were compared for the parameters profitability, esthetics, and patient satisfaction. With a thin layer thickness (0.8-0.9 mm circular), the tooth discoloration could not be adequately covered by any of the 360° veneers. After more extensive preparation, providing a circular thickness of the restoration up to 1.5 mm, all five monolithic materials as well as an additional individually veneered zirconium dioxide crown, serving as a reference, could achieve a satisfactory result. However, the overall esthetic appearance was completely rounded off by the individualized zirconium dioxide crown.

BACKGROUND: In Germany, the identification of unknown dead persons is the responsibility of the police. According to INTERPOL standards, primary (e.g., DNA, fingerprints, and teeth) and secondary (e.g., tattoos) characteristics are examined. Forensic dentistry is already used internationally as an efficient method. In this study, the approach of state police in Germany was analyzed. The methods used for identification, the role of forensic dentistry, the cooperation with dentists, and possible optimization approaches are investigated. METHODS: By means of a digital questionnaire, police officers competent in all federal states for the discovery of unknown dead bodies were asked about identification methods and specifically about the use of forensic dentistry. RESULTS: Eighty-five officers from at least 11 federal states participated in the survey. The procedure turned out to be department specific. In 72.6% of the cases, different characteristics are combined in the identification process, most frequently DNA with dental status (37.1%). DNA analysis is used most frequently. Of the respondents, 62.9% agreed that dental identification is used "often." The percentage of identifications using dental status is estimated to be 1.6-8.1%. For forensic dentistry, 19.4% have a fixed point of contact. A digital platform to contact dentists was estimated to be helpful by 56.5%. DISCUSSION: Forensic dentistry is currently still lagging behind DNA analysis, which could change through increasing digitalization if, for example, ante-mortem data are more reliably available and platforms for interdisciplinary exchange are created.

With the goal of shortening the postoperative healing phase and the minimization of the risk of peri-implantitis around dental implants, a polymer coating, with improved surface biocompatibility in the region of soft tissue penetration by the implant, was investigated. The polymer used was the relatively slowly resorbable poly-beta-hydroxybuterate (PHB) whose surface was further activated in a NH3--plasma. The influence of surface roughness of the substrate (commercially pure titanium) as well as the influence of the edge radii on the test samples was determined in prior studies. These studies formed the basis for an optimised coating process. In-vitro biocompatibility was determined using a human gingival primary cell culture. Surface morphology was determined with SEM and AFM to complement the cell culture studies.

Craniomandibular disorders are suggested to be responsible for many cases of chronic pain of the head and face. The assessment of dysfunctional factors in diseases of chronic head and facial pain normally requires special knowledge and equipment for the diagnosis and therapy of stomatognathic dysfunction. However, the first signs can be evaluated rather well without using complete equipment, which is not always available in general practice. It is therefore important that general practitioners have a simple, time-efficient method of routine screening based on sufficient methods and tests. Thus, we would like to present a questionnaire consisting of ten points that cover the valid elements of complete stomatognathic assessment. Answering these questions reveals signs of dysfunctional components of craniomandibular disorders, which indicate a dysfunction diagnosis and even better, consultation with a specialist.

Allergen-getriggerte lichenoide Mundschleimhautläsionen können sowohl beim oralen Lichen planus (OLP) als auch bei der oralen lichenoiden Läsion (OLL) auftreten. Klinisch und histologisch sind OLP und OLL nur schwer voneinander abzugrenzen. Ein OLP kann durch eine histologische Untersuchung gesichert werden. Dabei gilt der OLP als eine potenziell maligne Veränderung. Basierend auf aktuellen Daten der Literatur steht die OLL im Verdacht, ein erhöhtes Risiko einer malignen Transformation zu haben. Anhand eines klinischen Falles wird gezeigt, dass über eine interdisziplinäre Vorgehensweise in der Allergie- und Schleimhautdiagnostik ein Zusammenhang zwischen einer Kontaktallergie auf Amalgam und den lichenoiden Schleimhautveränderungen bestand. Die anschliessende Therapie zeigt exemplarisch die Schritte der zahnärztlichen Versorgungsmöglichkeiten bei multiplen Kontaktallergien auf Dentalmaterialien.

Verfärbungen von Schmelz und Dentin können das ästhetische Erscheinungsbild eines Menschen relevant beeinflussen. Anhand eines klinischen Fallbeispiels stellt der nachfolgende Artikel die prothetische Rehabilitation eines 20-jährigen Patienten dar, der sich aufgrund eines Traumas mit einer deutlichen Farbdiskrepanz am Zahn 11 vorstellte. Da mit einem internen Bleaching das gewünschte ästhetische Ergebnis nicht vollständig erzielt werden konnte, wurde der Zahn für die Aufnahme einer Restauration präpariert. Hierbei wurden zunächst möglichst minimalinvasiv verschiedene keramische 360°-Veneers (Schicht- dicke von 0,8 mm bis 0,9 mm) hergestellt. Als monolithische Werkstoffe wurden zwei klassische Silikat-, eine Lithiumdisilikat- und eine hochtransluzente Zirkoniumdioxidkeramik sowie ein indirektes Komposit verwendet. Es zeigte sich, dass bei dieser geringen Schichtdicke kein Werkstoff die Verfärbungen adäquat maskieren konnte. Deshalb wurde nach erneutem Substanzabtrag der Zahnstumpf zur Aufnahme einer Vollkrone (1,2 mm bis 1,5 mm zirkulär) vorbereitet und Kronen aus den gleichen monolithischen Werkstoffen wie zuvor verwendet. Die Kronen wurden mit einer individuell verblendeten Krone aus Zirkoniumdioxidkeramik (Referenz) verglichen. Auch nach zusätzlichem Substanzabtrag waren werkstoffabhängige Unterschiede im Maskierungseffekt festzustellen. In Bezug auf die Beurteilung des ästhetischen Gesamterscheinungsbildes war bei dem stark verfärbten Pfeilerzahn die individuell verblendete Krone den übrigen monolithischen Restaurationen überlegen.

Four two-component implants (Bonefit) inserted in a mandibular model were fitted with various overdentures and then subjected to tension analysis using wire strain gauges. The implants were positioned between the mandibular foramina of the model; data were obtained for mesial, distal, lingual and buccal compressive and tensile loads of 50 N on duplicates of the prosthodontic base at the level of the first molar, using a measuring wire gauge. The greatest forces were registered for the secondary-splint telescope crown prosthesis; these forces were up to three times as high as the corresponding axial load. In the case of bar attachments, it is not so much the strain on the implant when the prosthesis is loaded that tends to cause problems, but rather the original process of screwing down the overdenture on insertion. During this process, the implants are subjected to forces so high that the use of a torque indicator is deemed to be indispensable as a clinical consequence of this finding. For similar considerations, a conditionally removable bar construction should not be removed during follow-up examinations. Magnetically retained dentures, by contrast, barely exert any tensile forces on the implants.