DZZ International, 04/2020

For some years now, people working in science have been confronted with a new phenomenon: The annoyance caused by (exclusively English-language) e-mails in which the recipients are asked – usually after a friendly greeting (Tab. 1) – to publish an article in a journal mentioned in the mail (Tab. 2). The titles of these journals are largely unknown in the dental/medical world. Sometimes they resemble those of renowned specialist journals. In order to demonstrate the extent to which this practice has taken on, the e-mails of this kind received by the first author at his address between 1 and 31 January 2020 were stored and analyzed.

The advantages of ceramic materials are generally considered to be their tooth-like translucent appearance, their good biological compatibility in direct contact with the gingiva and a wear pattern that is comparable to that of enamel. These criteria are usually met by lithium silicate ceramics, which are indicated for veneers, tabletops, single crowns and small anterior bridges. If we wish to expand the indication range and integrate larger restorations in the posterior region, this objective is only achievable with zirconia ceramics. However, the higher fracture strength of zirconia is obtained at the expense of an opaque, less tooth-like appearance. This fact was initially not disturbing because the opaque framework was veneered with feldspathic ceramics. Since it has become technically possible, using the CAD/CAM process, to produce not only frameworks made of zirconia, but also complete restorations with occlusal surfaces, the high opacity of zirconia is no longer desirable from a clinical point of view. Developments in recent years have aimed to develop zirconias with the above-mentioned properties of silicate ceramics, which include combining translucency, biocompatibility, a tooth-like wear pattern with higher fracture strength and the possibility of CAD/CAM processing. These efforts have resulted in the development of different types of zirconia.

Anamnesis: The patient was 45 years old at the time of his first consultation in 2017. He was referred for the treatment of his "progressive periodontitis" and had not undergone previous periodontal therapy. The patient had no general diseases, took no medication and claimed to be a smoker (35 pack years). His main complaints were that he suffered from tooth hypersensitivity, tooth mobility, bleeding gums and pain on biting in the posterior right upper jaw. Clinical findings: Oral inspection revealed generalized soft and localized hard biofilm formation. Teeth 17–26 and 38–47 were present and they responded positively to sensitivity testing and negatively to percussion. The marginal gingiva appeared slightly edematous and swollen. There were generalized probing pocket depths of more than 7 mm and localized values up to 12 mm for teeth 45 and 46. The attachment level was generally above 7 mm and locally up to 13 mm for tooth 14. Grade I–III tooth mobility and grade 1–2 furcation involvement were recorded. Tooth 22 was elongated, rotated and protruded. Panoramic X-ray imaging revealed that the alveolar ridge was located in the apical third of the roots as well as the presence of multiple areas of furcation involvement and periapical translucencies. Diagnosis: – Periodontitis Stage IV, generalized, grade C with modifying risk factor smoking – Endo-periodontal lesion grade 3 at teeth 16 and 17 – Suspected endo-periodontal lesion at teeth 26, 38 and 47 – Suspected occlusal trauma at teeth 22 and 45 – Unharmonious anterior situation (multiple recessions, anterior teeth tipping towards vestibular, protrusion of tooth 22) Therapy: The patient quit smoking until re-evaluation. Teeth with a mobility grade ≥ II were splinted using composite. Root canal treatments of teeth 16, 17 and 26 as well as the functional reduction of teeth 22 and 45 were performed. Tooth 38 was extracted. Subsequently, anti-infective therapy ensued in form of a full-mouth-disinfection with adjuvant antibiotics. After re-evaluation and supportive periodontal therapy (SPT), corrective periodontal surgery of teeth with persisting probing pocket depths ≥ 6mm was performed by means of distal wedge excisions, root amputations and furcation tunneling. Six months after periodontal surgery, the periodontium appeared stable. According to the patient, there were subjective deficiencies due to interdental black triangles, recessions and tooth tipping towards vestibular in the anterior region. Thus, direct shape corrections of teeth 14–24 and 34–44 and closure of the inter-dental gap between teeth 43 and 44 followed. Conclusion: After successful periodontal treatment, functional corrections and direct restorative techniques with composite can be used even for patients with severe periodontal disease in order to achieve minimally invasive and successful treatment outcomes. Keywords: adjuvant antibiotic administration for subgingival instrumentation, direct composite splinting, endo-periodontal lesion, endodontic therapy, esthetics, furcation tunneling, rehabilitation, resective periodontal surgery, root amputation, shape correction, smoking cessation, tooth widening

Introduction: Ewald Harndt (1901–1996) has shaped modern German den-tistry like hardly any other scientist: The leading national professional society (DGZMK) elected him its president (1957–1965), the Free University of Berlin appointed him its rector (1967–1969), and the German Dental Association (BZÄK) awarded him the Fritz-Linnert Badge of Honour (1991). He received similar awards and honours throughout the world. Discussion: While Harndt's professional and academic achievements are undisputed, there is still a lack of clarity regarding his role in the Third Reich: On the one hand, he was dismissed in 1945 due to his membership in the Nazi Party (NSDAP), on the other hand, more recent articles point out that Harndt was considered a political suspect in the Nazi state and thus place him close to an opponent or even victim of the Nazi regime. Against this background, the present paper aims to illuminate Harndt's relationship to National Socialism. The methodological basis is a comprehensive analysis of the available archival sources and contemporary printed material and a systematic re-evaluation of the secondary literature on Ewald Harndt. Results: It can be shown that Harndt made a number of inconsistent, false or euphemistic statements, particularly in the denazification process. The source analysis leads to the conclusion that Harndt cannot be classified as a victim but as a political follower. He was undoubtedly not a "fervent" National Socialist, but he served the regime as a member of various Nazi organizations and networks, as well as by endorsing Nazi "health policy" and using Nazi terms – notably in the fields of eugenics ("vererbt geistig minderwertige Kinder", "Unfruchtbarmachung", "Blutsverwandtschaft") and religion ("deutschreli-giös"). Keywords: Eugenics, History of Dentistry, Third Reich

Introduction: Oral microorganisms can contribute to the pathogenesis of many diseases in the oral cavity such as caries, periodontitis, peri-implantitis and denture-related stomatitis. Yet, oral microorganisms may also have a considerable influence on the onset of systemic medical conditions such as lung or cardiovascular diseases. Microorganisms are organized in biofilms and they colonize teeth, mucosa, and dental restorations; the extent to which biofilms are accessible during self-performed oral hygiene varies widely. Discussion: The current demographic trends show that the population is getting older and that an increasing number of elderly and multimorbid patients require nursing care, most of whom already have and/or will receive removable dentures in the future. Impaired motor skills and cognitive abilities often lead to difficulties in self-performed oral hygiene, thus making these patients reliant on others for assistance. The regular accumulation of biofilm on removable dentures, which is not sufficiently removed, may trigger and foster the onset of oral and systemic diseases in immunologically compromised patients. Usually, removable dentures are fabricated from polymeric mate-rials and polymethylmethacrylate is the most frequently used material. In spite of this, many new materials are currently being introduced on the market which can be used to make removable dentures. The range of available materials has become increasingly broad and it includes materials based on polymethylmethacrylate as well as composite-based materials and polymeric materials with a distinct polymer chemistry. Relevant differences exist between the bioadhesion of materials that are processed using classical methods as compared to CAD/CAM-manufacturing. Conclusion: In this context, the current article aims to describe the impor-tance of biofilms on removable dentures, to outline relevant interactions of oral microorganisms with the surface of polymeric materials, and to present strategies for minimizing bioadhesion on removable dentures. Keywords: polymeric materials, CAD/CAM-manufacturing, biofilms, microorganisms, removable dentures