Background: Regarding the new dental licensing regulations in Germany (AOZ), this study evaluated the effectiveness of two different digital tooth preparation validation systems in comparison to traditional faculty feedback. Methods: Participants were randomly divided into groups: Faculty Feedback (FF: n = 33), PrepCheck® (PC: n = 32) and Dental Teacher™ (n = 32). Students had the task to prepare tooth 16 for a retentive full-cast crown. Preparations could be repeated as often as desired. Feedback was provided either by faculty staff or by digital validation systems only. Exams were conducted and graded by two independent and experienced examiners. A survey was performed to evaluate the assessment concepts. Results: No statistical difference in examination performance between groups could be observed. Nevertheless, the survey showed participants preferred consulting the faculty staff rather than the digital validation systems. Students preferred practising with DT rather than with PC. Conclusions: Although both classical and digital methods showed comparable results regarding the preparation examination performance, direct feedback by the faculty staff is still appreciated by the students. A combination of both methods is mandatory since demonstration and advice by the teacher is needed. However, digital tooth preparation validation systems are predestined for free practice sessions, providing self-assessment.

The objective of this study was to evaluate the impacts of different sandblasting procedures in acid etching of Ti6Al4V surfaces on osteoblast cell behavior, regarding various physicochemical and topographical parameters. Furthermore, differences in osteoblast cell behavior between cpTi and Ti6Al4V SA surfaces were evaluated. Sandblasting and subsequent acid etching of cpTi and Ti6Al4V discs was performed with Al2O3 grains of different sizes and with varying blasting pressures. The micro- and nano-roughness of the experimental SA surfaces were analyzed via confocal, atomic force and scanning electron microscopy. Surface free energy and friction coefficients were determined. hFOB 1.19 cells were seeded to evaluate adhesion, proliferation and osteoblastic differentiation for up to 12 d via crystal violet assays, MTT assays, ALP activity assays and Alizarin Red staining assays. Differences in blasting procedures had significant impacts on surface macro- and micro-topography. The crystal violet assay revealed a significant inverse relationship between blasting grain size and hFOB cell growth after 7 days. This trend was also visible in the Alizarin Red assays staining after 12 d: there was significantly higher biomineralization visible in the group that was sandblasted with smaller grains (F180) when compared to standard-grain-size groups (F70). SA samples treated with reduced blasting pressure exhibited lower hFOB adhesion and growth capabilities at initial (2 h) and later time points for up to 7 days, when compared to the standard SA surface, even though micro-roughness and other relevant surface parameters were similar. Overall, etched-only surfaces consistently exhibited equivalent or higher adhesion, proliferation and differentiation capabilities when compared to all other sandblasted and etched surfaces. No differences were found between cpTi and Ti6Al4V SA surfaces. Subtle modifications in the blasting protocol for Ti6Al4V SA surfaces significantly affect the proliferative and differentiation behavior of human osteoblasts. Surface roughness parameters are not sufficient to predict osteoblast behavior on etched Ti6Al4V surfaces.

Objectives: Aim of this study was to compare the soft tissue response to implant abutments made of titanium, zirconia, zirconia veneered with feldspar ceramics and PEEK by various clinical, histological, microbiological, and molecular biological markers in an experimental model. Materials and Methods:A total of 40 experimental one-piece healing abutments of four different materials were mounted on bone level implants in 20 volunteering patients (split-mouth design). After a three-month period of open healing, clinical parameters at the abutments were assessed and adjacent mucosa was sampled for inflammatory cytokine mRNA concentrations and histological analysis by a novel method. In addition, PISF samples were obtained for the analysis of periodontopathogenic bacteria counts and active MMP-8 levels. Marginal bone level change was measured by intra oral radiographs.Results: Abutments of the different materials did not exhibit significant differences regarding clinical parameters, pathogenic bacteria counts or pro-inflammatory cytokine concentrations. Likewise, no significant differences were detected regarding soft tissue morphology or bone level change. Compared to titanium abutments, significantly less mononuclear inflammatory cells were detected in the mucosa at abutments made of zirconia veneered with feldspar ceramics.Conclusions: All examined abutment materials exhibited a similar soft tissue response compared to titanium and histological data did not reveal early signs of elevated inflammation caused by PEEK-and feldspar-veneered zirconia abutments. Due to the short observation period and the small sample size, a final conclusion on the long-term suitability of those abutment materials cannot be drawn. However, based on the presented data, we consider further studies on that subject as appropriate.

No abstract

Introduction: Otological symptoms are often associated with temporomandibular joint disorders (TMD). The exact correlation between these two phenomena is being controversially discussed in the literature for many years. This retrospective study aims to investigate the possible association of otological symptoms with specific TMD findings, as well as stress and chronic pain. Method: We analyzed the anonymized medical records of 56 patients. This included the assessment of the clinical functional status and Manual Structural Analysis (MSA) in accordance to the German Society for Functional Diagnostics and Therapy (DGFDT) and the Graded Chronic Pain Status (GCPS). Results: From all 56 patients with TMD 32 had otological symptoms. The most common TMD symptoms in patients with aural complains were pain by palpation of the m. masseter (81,82-83,33%) and m. digastrics venter posterior (81,82% -100%). Articular sounds were a prevalent finding especially in tinnitus patients (63,64%). An insufficient posterior static occlusion was present in 27,27% -50% of the cases. Approximately half of the patients with aural complaints mentioned, that they feel stressed. Most of the patients suffered from a functional chronic pain (56,25%). A dysfunctional chronic pain was prevalent in 18,75% of the cases. Conclusion:The results indicate, that TMD patients with aural complaints have most often pain in the areas of m. digasticus venter posterior and m. masseter, so there might be an association of ear symptoms with a pathology of these muscles. However, no causal relationship could be proven. Arthropathology, malocclusion, psychological condition and stress levels are other factors, that seem to have influence. The etiology is multifactorial and remains unclear.