Evaluation of Insertion Energy as Novel Parameter for Dental Implant Stability

Insertion energy has been advocated as a novel measure for primary implant stability, but the effect of implant length, diameter, or surgical protocol remains unclear. Twenty implants from one specific bone level implant system were placed in layered polyurethane foam measuring maximum insertion torque, torque–time curves, and primary stability using resonance frequency analysis (RFA). Insertion energy was calculated as area under torque–time curve applying the trapezoidal formula. Statistical analysis was based on analysis of variance, Tukey honest differences tests and Pearson’s product moment correlation tests (α = 0.05). Implant stability (p = 0.01) and insertion energy (p < 0.01) differed significantly among groups, while maximum insertion torque did not (p = 0.17). Short implants showed a significant decrease in implant stability (p = 0.01), while reducing implant diameter did not cause any significant effect. Applying the drilling protocol for dense bone resulted in significantly increased insertion energy (p = 0.02) but a significant decrease in implant stability (p = 0.04). Insertion energy was not found to be a more reliable parameter for evaluating primary implant stability when compared to maximum insertion torque and resonance frequency analysis

Comparison of extraction sites versus artificial defects with xenogenic bone substitute in minipigs

Objectives The preclinical evaluation of bone substitutes is frequently performed in artificially created defects. However, such defects do not reflect the predominant clinical application of bone substitutes for socket preservation. Hence, the goal of this animal study was to compare the performance of a xenogenic bone substitute in extraction sites versus artificial defects. Material and Methods Four study sites each were created in the mandibles of four minipigs in the region of the third premolars and first molars, respectively. On one side, fresh extraction sockets were established while contralaterally trephine defects were created in healed alveolar bone. All sites were augmented using a particulate xenogenic bone substitute, covered by resorbable membranes and allowed to heal for 12 weeks. The amounts of new bone, non-bone tissue and remaining bone substitute granules were quantified through histological and micro-CT analysis. Comparative statistics were based on t-tests for two samples and ANOVA with the level of significance set at α = 0.05. Results Histomorphometric data from only two animals could be quantitatively analyzed due to difficulty with identifying the surgical sites. The percentage of newly formed bone ranged between 53.2% ± 5.6% for artificial defects and 54.9% ± 12.4% for extraction sites. With the exception of ANOVA indicating a greater amount of non-bone tissue in extraction sites as compared to artificial sites (p = 0.047), no statistically significant differences were observed. Micro-CT scans showed patterns similar to the ones observed in histomorphometry. As extraction sites could be identified only in two micro-CT reconstructions, quantitative assessment was not undertaken. Conclusions Despite the comparable performance of bone substitute material in artificial defects and extraction sites found here, the data gathered with this experiment was insufficient for showing equivalence of both approaches

Students at Saarland University dental school-A survey on their background and curriculum perception

Introduction With the aim of optimising dental education without overburdening students, new legislation restructuring the undergraduate dental curriculum in German is under way. The goal of this study was to survey the current situation of dental students at one specific university with respect to their socio-economic background, admission to dental school, curriculum perception and work-life balance. Materials and methods An online questionnaire was presented to all undergraduate students enrolled at Saarland University who had at least completed the first preclinical practical course in dentistry. Results A response rate of 85% was reached with two-thirds of the student body being females. The profession of 40% of students' parents either was physicians or dentist. Students reported a slight reduction in time spent for leisure activities during their studies, however, with sports activities hardly being affected. With respect to a proper work-life balance, almost 50% of respondents considered their clinical workload as being too high. Students did not express a clear opinion regarding curriculum structure, whilst the content mostly satisfied their expectations (59%). The majority (71%) of students considered their preclinical training as being demanding whilst less than 3% fully agreed that preclinical training provided an optimal background for patient treatment. The learning modules in the first clinical semester were considered as being adequate by 56% of students. Examinations during courses were seen as properly reflecting the students' knowledge by 79% of students. Discussion The status quo of German dental students is characterised by a high workload affecting the students' work-life balance and by a transition between preclinical and clinical education which only about half the student body perceives as being adequate. Patient-based examinations obviously are not considered as being problematic

Heat below the City – Is temperature a key driver in urban groundwater ecosystems?

Living in an urban groundwater ecosystem comes with many challenges for its inhabitants. In Central Europe, groundwater fauna has adapted to a dark, cold, and typically energy-poor habitat for thousands of years, making these highly specialised animals susceptible to short-term (years to decades) changes in environmental conditions. In urban areas, many anthropogenic pressures like surface sealing, subsurface infrastructures, organic pollution, or accumulation of toxicants impact the groundwater ecosystem. On top, the urban subsurface is heating up with an enormous speed, characterized by the formation of subsurface urban heat islands. With urban groundwater temperatures continuously increasing way beyond natural background values, a loss of biodiversity and ecosystem functioning with ultimately a deterioration of water quality is predicted. In the current research project ‘Heat below the City’, we target the urban groundwater ecosystems of the city of Vienna, Austria. 150 groundwater wells distributed all over the city have been sampled twice, in autumn 2021 and spring 2022. Groundwater samples are analysed for a large set of physical-chemical, microbiological and faunistic variables, aiming to identify main drivers of groundwater ecosystem biodiversity and functioning. The focus lies on temperature induced cascading effects that may lead from ecologically intact oxic habitats to anoxic zones lacking fauna with deteriorated water quality. First findings show mean groundwater temperatures in Vienna to be at 14°C, about 3°C above the natural background, with anthropogenic heat sources having a main impact on the distribution and degree of warming. The absence of dissolved oxygen (DO) and NO3- as well as the presence of Fe2+, S2- and CH4 hint at zones of reduced groundwater below the city. First data on physical-chemical conditions, microbiological and faunal communities will be introduced

Students at Saarland University dental school—A survey on their background and curriculum perception

Introduction With the aim of optimising dental education without overburdening students, new legislation restructuring the undergraduate dental curriculum in German is under way. The goal of this study was to survey the current situation of dental students at one specific university with respect to their socio-economic background, admission to dental school, curriculum perception and work-life balance. Materials and methods An online questionnaire was presented to all undergraduate students enrolled at Saarland University who had at least completed the first preclinical practical course in dentistry. Results A response rate of 85% was reached with two-thirds of the student body being females. The profession of 40% of students' parents either was physicians or dentist. Students reported a slight reduction in time spent for leisure activities during their studies, however, with sports activities hardly being affected. With respect to a proper work-life balance, almost 50% of respondents considered their clinical workload as being too high. Students did not express a clear opinion regarding curriculum structure, whilst the content mostly satisfied their expectations (59%). The majority (71%) of students considered their preclinical training as being demanding whilst less than 3% fully agreed that preclinical training provided an optimal background for patient treatment. The learning modules in the first clinical semester were considered as being adequate by 56% of students. Examinations during courses were seen as properly reflecting the students' knowledge by 79% of students. Discussion The status quo of German dental students is characterised by a high workload affecting the students' work-life balance and by a transition between preclinical and clinical education which only about half the student body perceives as being adequate. Patient-based examinations obviously are not considered as being problematic

Suppressor of Cytokine Signaling-3 Antagonizes cAMP Effects on Proliferation and Apoptosis and Is Expressed in Human Prostate Cancer

Interleukin-6, levels of which are elevated in prostate cancer, activates different signal transduction pathways including that of Janus kinases/signal transducer and activator of transcription (STAT)3. However, phosphorylation of STAT3 has been reported to be associated with either stimulatory or inhibitory effects on cellular proliferation. To better understand the mechanisms of STAT3 regulation in benign and malignant prostate, we have investigated the role of suppressor of cytokine signaling (SOCS)-3. Cell lines that did not express phosphorylated STAT3 were found to be SOCS-3-positive. SOCS-3 was re-expressed in LNCaP cells after treatment with a demethylating agent. SOCS-3 immunohistochemistry revealed a negative or weak reaction in benign areas, whereas its expression was detected in tumor tissue. To investigate the involvement of SOCS-3 in regulation of cellular events, we incubated cancer cells with a cAMP derivative. This treatment yielded higher SOCS-3 levels, reduced [(3)H]thymidine incorporation, and increased percentage of apoptotic cells. However, down-regulation of SOCS-3 by a short interfering RNA approach resulted in inhibition of proliferation and an increased apoptotic rate. Collectively, our results show that SOCS-3 antagonizes regulation of cellular events by cAMP and is expressed in human prostate cancer