Vertical bone augmentation utilizing a titanium-reinforced PTFE mesh: A multi-variate analysis of influencing factors.

OBJECTIVE: To clinically evaluate the use of a titanium-reinforced PTFE mesh for vertical bone augmentation (VBA) of deficient alveolar ridges. MATERIALS AND METHODS: This case series documented consecutive patients treated for VBA with a newly developed PTFE mesh. VBA was performed in anterior and posterior, maxillary and mandibular arches using anorganic bovine bone combined with autogenous graft in a 1:1 ratio. Healing time from initial surgery to re-opening was recorded. Baseline vertical deficiency, absolute bone gain (gross height gained), and relative gain (percentage of defect fill with respect to the baseline deficiency) were registered. RESULTS: Fifty-seven patients (65 defects) were included in the analysis. The mean baseline vertical deficiency was 5.5 ± 2.6 mm. The mean absolute bone gain was 5.2 ± 2.4 mm. A relative gain of 96.5 ± 13.9% was achieved. Overall, 89.2% of cases showed complete regeneration, which occurred in all sites with baseline deficiencies of <5 mm, in 95.6% of sites with 5-8 mm deficiencies, and in 89.4% of sites with >8 mm deficiencies. Each 1-mm addition to the baseline height deficiency increased the likelihood of incomplete bone regeneration by 2.5 times. Defect location had a statistically significant but a limited clinical impact on the bone height gained (<0.5 mm). Complications were observed in three cases (3%). CONCLUSIONS: Vertical bone augmentation with titanium-reinforced PTFE mesh and a mixture of autologous bone and xenograft is a safe and predictable procedure. The extent of the baseline vertical deficiency influences the percentage of bone gained.

Bioactive coatings for dental implants: A review of alternative strategies to prevent peri-implantitis induced by anaerobic bacteria.

Members of oral bacterial communities form biofilms not only on tooth surfaces but also on the surface of dental implants that replace natural teeth. Prolonged interaction of host cells with biofilm-forming anaerobes frequently elicits peri-implantitis, a destructive inflammatory disease accompanied by alveolar bone loss leading to implant failure. Here we wish to overview how the deposition of bioactive peptides to dental implant surfaces could potentially inhibit bacterial colonization and the development of peri-implantisis. One preventive strategy is based on natural antimicrobial peptides (AMPs) immobilized on titanium surfaces. AMPs are capable to destroy both Gram positive and Gram negative bacteria directly. An alternative strategy aims at coating implant surfaces - especially the transmucosal part - with peptides facilitating the attachment of gingival epithelial cells and connective tissue cells. These cells produce AMPs and may form a soft tissue seal that prevents oral bacteria from accessing the apical part of the osseointegrated implant. Because a wide variety of titanium-bound peptides were studied in vitro, we wish to concentrate on bioactive peptides of human origin and some of their derivatives. Furthermore, special attention will be given to peptides effective under in vivo test conditions.

Biomechanical properties of the bone during implant placement.

BACKGROUND: In this research the biomechanical properties of a bone model was examined. Porcine ribs are used as experimental model. The objective of this research was to investigate and compare the biomechanical properties of the bone model before and after implant placement. METHODS: The bone samples were divided in three groups, Group 1 where ALL-ON-FOUR protocol was used during pre-drilling and placing the implants, Group 2 where ALL-ON-FOUR protocol was used during pre-drilling, and implants were not placed, and Group 3 consisting of intact bones served as a control group. Static and dynamic loading was applied for examining the model samples. Kruskal-Wallis statistical test and as a post-hoc test Mann-Whitney U test was performed to analyze experimental results. RESULTS: According to the results of the static loading, there was no significant difference between the implanted and original ribs, however, the toughness values of the bones decreased largely on account of predrilling the bones. The analysis of dynamic fatigue measurements by Kruskal-Wallis test showed significant differences between the intact and predrilled bones. CONCLUSION: The pre-drilled bone was much weaker in both static and dynamic tests than the natural or implanted specimens. According to the results of the dynamic tests and after a certain loading cycle the implanted samples behaved the same way as the control samples, which suggests that implantation have stabilized the skeletal bone structure.

Effects of different decontaminating solutions used for the treatment of peri-implantitis on the growth of Porphyromonas gingivalis-an in vitro study.

Implants have been considered the treatment of choice to replace missing teeth, unfortunately, peri-implant disease is still an unresolved issue. Contaminated implants may be decontaminated by physical debridement and chemical disinfectants; however, there is a lack of consensus regarding the ideal techniques/agents to be used for the decontamination. The objective of our study was to compare the decontaminating efficacy of different chemical agents on a titanium surface contaminated with Porphyromonas gingivalis, a typical representative of the bacterial flora associated with peri-implantitis. Commercially pure Ti grade 4 discs with a polished surface were treated with a mouthwash containing chlorhexidine digluconate (0.1%), povidone-iodine (PVP-iodine) solution (10%) or citric acid monohydrate (40%). Qualitative and quantitative assessment of cellular growth and survival were assessed by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and scanning electron microscopy (SEM). Significant differences in the quantity of P. gingivalis could be observed after 6 days of incubation. A numerical, but not statistically significant (P = 0.066) decrease in the amount of living bacteria was observed in the group treated with the PVP-iodine solution as compared to the control group. The chlorhexidine (CHX)-treated group presented with significantly higher cell counts, as compared to the PVP-iodine-treated group (P = 0.032), while this was not observed compared to the control group and citric acid-treated group. Our results have also been verified by SEM measurements. Our results suggest that for P. gingivalis contamination on a titanium surface in vitro, PVP-iodine is a superior decontaminant, compared to citric acid and chlorhexidine-digulconate solution.

Lessons on the Sigma-1 Receptor in TNBS-Induced Rat Colitis: Modulation of the UCHL-1, IL-6 Pathway.

Inflammatory Bowel Disease (IBD) is an autoimmune ailment of the gastrointestinal (GI) tract, which is characterized by enhanced activation of proinflammatory cytokines. It is suggested that the sigma-1 receptor (σ1R) confers anti-inflammatory effects. As the exact pathogenesis of IBD is still unknown and treatment options are limited, we aimed to investigate the effects of σ1R in 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced experimental colitis. To this end, male Wistar-Harlan rats were used to model colitic inflammation through the administration of TNBS. To investigate the effects of σ1R, Fluvoxamine (FLV, σ1R agonist) and BD1063 (σ1R antagonist) were applied via intracolonic administration to the animals once a day for three days. Our radioligand binding studies indicated the existence of σ1Rs as [3H](+)-pentazocine binding sites, and FLV treatment increased the reduced σ1R maximum binding capacity in TNBS-induced colitis. Furthermore, FLV significantly attenuated the colonic damage, the effect of which was abolished by the administration of BD1063. Additionally, FLV potentially increased the expression of ubiquitin C-terminal hydrolase ligase-1 (UCHL-1) and the levels of endothelial nitric oxide synthase (eNOS), and decreased the levels of interleukin-6 (IL-6) and inducible NOS (iNOS) expression. In summary, our study offers evidence for the anti-inflammatory potential of FLV and σ1R in experimental colitis, and our results present a promising approach to the development of new σ1R-targeted treatment options against IBD.

Fracture behavior of root-amputated teeth at different amount of periodontal support - a preliminary in vitro study.

BACKGROUND: The purpose of this study was to evaluate the effect of the amount of periodontal support on the fracture resistance of root-amputated maxillary molar teeth restored with either direct class. I. restorations or class II. mesio-occluso-distal (MOD) indirect overlay restorations with cuspal coverage. METHODS: Sixty sound maxillary first molars were collected and randomly divided into four groups. In Groups 1 and 2, MOD cavities were prepared and all cusps were reduced by 2 mm, whereas in Group 3 and 4, only a conservative Class I. cavity was prepared. Subsequently, root canal treatment was performed and the mesio-buccal roots were amputated. Groups 1 and 2 were restored with indirect composite overlay, while Groups 3 and 4 received direct composite fillings. After restoration, teeth were embedded as follows: Groups 1 and 3: normal bone level, Groups 2 and 4: furcation involvement. The specimens were submitted to static fracture resistance testing. Fracture thresholds and fracture patterns were measured and evaluated. RESULTS: Group 1 had the highest fracture resistance (2311,6 N) among the restored groups and showed statistically significant difference compared to Group 2 (p = 0.038) and Group 4 (p = 0.011). There was no statistically significant difference in terms of fracture resistance between the rest of the groups. In terms of the fracture patterns, Group 3 was characterized by the highest percentage (60%) of mostly favorable fractures, while the rest of the groups showed predominantly unfavorable ones. CONCLUSIONS: The amount of periodontal support seems to influence the fracture resistance of root-amputated and restored maxillary molars.

H2S confers colonoprotection against TNBS-induced colitis by HO-1 upregulation in rats.

Hydrogen sulfide (H2S) is an endogenous mediator that contributes to many important physiological processes including vasodilation and vascular smooth muscle relaxation; in turn, preventing tissue damage and reducing inflammation. Heme oxygenase (HO) enzymes, of which HO-1 is inducible by harmful stimuli, were found to regulate intestinal inflammation in experimental animal models of colitis. We aimed to investigate the protective effects of H2S against 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats, and whether HO enzyme system is involved in the H2S-induced colonic cytoprotection. Male Wistar rats were treated with TNBS to induce colitis, and H2S donor (Lawesson's reagent) was prepared two times/day at different concentrations, and delivered per os (from day 1 to day 3). Our results suggest that daily treatment (2 times/day) with H2S donor, could significantly decrease the extent of colonic inflammation compared to vehicle treatment, and the most effective daily dose of H2S donor against inflammation was 18.75 µM/kg/day. Per os administration of H2S donor increased the colonic HO enzyme activity; on the contrary, the protective effect of H2S was abolished by the co-treatment with HO inhibitor. Our findings suggest that H2S confers colonoprotection, probably by modulation of anti-inflammatory parameters and HO enzyme activity.

Idiopathic male infertility related to periodontal and caries status.

OBJECTIVES: This study was undertaken to evaluate the possible correlation between the periodontal and dental status and sperm pathology in idiopathic male infertility. METHODS: The periodontal and caries status and semen quality of 199 men presented with unexplained male infertility were examined. Periodontal and dental factors were analysed by sperm pathology categories. RESULTS: A total of 106 men had normal sperm parameters, whereas 93 men had some type of spermpathology; 27.95% had oligozoospermia, 23.65% asthenozoospermia, 16.12% cryptozoospermia, 32.25% combined oligo-asthenozoospermia. Poor periodontal status was found in about half of the study group (45.7%). The DMFT index was not a significantly higher in any of the spermpathology groups. The odds ratio of calculus, bleeding on probing (BOP) and BOP at ≥50% of the teeth were significantly higher in the combined group (AOR = 1.04, AOR = 1.13, AOR = 4.92, respectively) in multivariate analyses compared to those in the normozoospermia group. Gingival bleeding in the history and urban residency were the only predictors for pathospermia shown by the logistic regression model (AORs were 1.82 and 2.26, respectively). CONCLUSIONS: Some features of poor periodontal status, as gingival bleeding in the history, presence of calculus and BOP, were associated with oligo+asthenozoospermia in men with idiopathic infertility.

1-[3-(2-Hydroxyethylsulfanyl)propanoyl]-3,5-bis(benzylidene)-4-piperidones: A novel cluster of P-glycoprotein dependent multidrug resistance modulators.

A series of 1-[3-(2-hydroxyethylsulfanyl)propanoyl]-3,5-bis(benzylidene)-4-piperidones 4a-e display promising P-glycoprotein dependent multidrug resistance (MDR) revertant properties and are significantly more potent than a reference drug verapamil when evaluated against L-5178Y MDR lymphoma cells. These dienones may be referred to as dual agents having both MDR revertant properties and tumour-selective cytotoxicity. In particular, 3,5-bis(4-chlorobenzylidene)-1-[3-(2-hydroxyethylsulfanyl]propanoyl-4-piperidone 4d emerged as a lead molecule for further development based on its MDR revertant properties, cytotoxic potencies and tumour-selective toxicity. The structure-activity relationships reveal important structural requirements for further designing of potent MDR revertants.

[Forensic analysis of injuries in dentistry]. / Fogászati jellegu sérülések törvényszéki vizsgálata.

INTRODUCTION: Documentation and evaluation of dental injuries in forensic medicine are rather problematic. It needs a professional work up why dental injuries are out of focus, and how the diagnosis, pattern and treatment are influenced by novel approaches of dentistry. AIM: The aims of the authors were to characterize dental injuries, to compare their own findings to literature data concerning the type and characteristics of injuries, and propose a diagnostic workflow. METHOD: Expert's reports between 2009 and 2013 at the Department of Forensic Medicine, University of Szeged were reviewed. RESULTS: Review of about 7000 reports revealed only 20 cases with dental injury, which is in contrast with literature data indicating a significantly higher frequency of dental injuries. CONCLUSIONS: Although the number of "dental cases" was low, there were several additional cases where the trauma probably affected the teeth but the injury was not documented. In future more attention is needed in forensic evaluation of the mechanism, therapeutic strategy and prognosis of dental injuries.

[Role of cone-beam computed tomography in diagnostic otorhinolaryngological imaging]. / A cone-beam komputertomográfia alkalmazása a fül-orr-gégészeti képalkotásban.

Accurate diagnosis and preoperative planning in modern otorhinolaryngology is strongly supported by imaging with enhanced visualization. Computed tomography is often used to examine structures within bone frameworks. Given the hazards of ionizing radiation, repetitive imaging studies exponentially increase the risk of damages to radiosensitive tissues. The authors compare multislice and cone-beam computed tomography and determine the role, advantages and disadvantages of cone-beam computed tomography in otorhinolaryngological imaging. They summarize the knowledge from the international literature and their individual imaging studies. They conclude that cone-beam computed tomography enables high-resolution imaging and reconstruction in any optional plane and in space with considerably lower effective radiation dose. Cone-beam computed tomography with appropriate indications proved to be an excellent diagnostic tool in otorhinolaryngological imaging. It makes an alternative to multislice computed tomography and it is an effective tool in perioperative and postoperative follow-up, especially in those cases which necessitate repetitive imaging with computed tomography.

Dimensional Accuracy of Two-Step Impressions Measured on Scanned Casts in CAD.

PURPOSE: The purpose of the study was to find out how light-body impression material thickness influences the horizontal dimensional accuracy of casts examined on a scanned model. MATERIALS AND METHODS: Customized manikin mandibles were used for impression taking with a dual-phase impression method. These mandibles were prepared in a way that allowed the control of light-bodied impression material thickness. First premolars were prepared for a full crown by supragingival chamfer on both sides in all mandibles. For the measurements, buccal and lingual reference points were made at the preparation margin. Impressions were taken at nine thickness levels and a control level (TTotal = 10; 0-1.2 mm), and the reference points' average distance was compared across thickness levels on both the left and right side. We carried out three measures for each specimen and used three specimens per thickness level. Total sample size was N = 180, creating a sizable database to understand the influence. RESULTS: The results indicated that light-body impression material thickness had no influence on the horizontal dimension of a die measured on scanned dies in these specific circumstances. CONCLUSIONS: The thickness of light-body impression material in the dual-phase impression taking technique did not have a significant influence on the horizontal accuracy of scanned dies, which makes the technique safe and reliable for single crown restorations without having to take extra precautions for the thickness of light-body impression material.

Application and Future Utilization of Shellac in Orthodontics: A Systematic Review.

Background: This review examines the application of shellac in orthodontics, focusing on its properties, advantages, and potential as an alternative to conventional materials. In orthodontics, where bond strength, ease of application, and removal are paramount, shellac's capabilities meet these needs while supporting environmentally friendly practices. Methods: With objectives centered on evaluating shellac's effectiveness, biocompatibility, and impact on patient outcomes, a comprehensive search across multiple databases was conducted, including PubMed, Scopus, and Web of Science. This study's selection criteria targeted studies assessing shellac's use in orthodontic applications, measuring treatment effectiveness, biocompatibility, and patient satisfaction while excluding those not directly involving orthodontic applications or lacking empirical data. Results: Through a qualitative synthesis of the extracted data-encompassing study design, sample size, treatment outcomes, and adverse effects-the findings reveal shellac's potential benefits in orthodontics, such as enhanced patient comfort and comparable treatment outcomes to traditional materials. However, the review also notes variability in study designs and outcomes, indicating the need for further research. Conclusions: This study concluded that shellac presents a promising alternative in orthodontic materials, recommending additional studies to standardize assessment methodologies and confirm its long-term advantages.

Evaluation of Vaccine Immunogenicity-Correlates to Real-World Protection: Influenza.

Recent events highlighted that, despite decades of studying vaccine immunogenicity and efforts toward finding correlates of protection, evaluating real-world vaccine efficacy as well as establishing meaningful licensing criteria still represents a significant challenge. In this paper, we review all aspects of influenza vaccine immunogenicity, including animal and human challenge studies, humoral and cellular immunity parameters, and their potential correlation with real-life protection from disease.

Oral Health Status and Factors Related to Oral Health in Patients with Schizophrenia: A Matched Case-Control Observational Study.

Background: Schizophrenia (SCZ) patients have disproportionately poor oral health outcomes owing to a multidimensional set of factors, such as pathophysiology of the disease, drug-related adverse effects and lower utilization rate of dental healthcare services. The aim of the present observational study was to compare the indicators of dental and periodontal health in patients with SCZ to those of nonaffected healthy controls; furthermore, the influence of various anamnestic factors and lifestyle habits on oral health status were also assessed. Methods: A total of 50 SCZ patients-in remission-receiving treatment at the Department of Psychiatry, University of Szeged, were compared with 50 age- and gender-matched healthy controls attending the Faculty of Dentistry, University of Szeged. Participants' dental (decayed, missing and filled surfaces [DMF-S] and decayed, missing and filled teeth [DMF-T]) and periodontal (plaque index [%], bleeding on probing [BOP%], pocket depth [PD] and attachment loss [AL]) status was measured according to the World Health Organization (WHO) criteria. Results: In total, 74.0%, 80.0% and 78.0% of SCZ patients received second-generation antipsychotics, benzodiazepines and mood stabilizers, respectively. Patients with SCZ had significantly higher DMFs (81.30 ± 40.16 vs. 61.64 ± 40.56; p = 0.010), D (8.18 ± 7.73 vs. 4.18 ± 4.22; p < 0.001) and DMF-T (18.20 ± 8.36 vs. 14.42 ± 8.21; p = 0.024) scores but significantly lower F (1.84 ± 0.29 vs. 4.62 ± 3.98; p < 0.001) scores compared to the controls; male subjects had significantly lower DMFs (74.52 ± 39.72 vs. 90.67 ± 39.1; p = 0.020) and DMF-T (16.52 ± 8.12 vs. 20.52 ± 8.32; p = 0.031) scores. Additionally, SCZ patients had significantly higher plaque indices (56.96 ± 23.19 vs. 27.44 ± 17.53; p < 0.001), BOP% (58.96 ± 22.89 vs. 23.56 ± 17.53; p < 0.001), PD (2.84 ± 0.67 vs. 2.19 ± 0.49; p = 0.024) and AL (3.39 ± 1.72 vs. 2.49 ± 0.76; p < 0.001) values compared to controls. Smoking > 10 cigarettes/day was associated with worse dental and periodontal indices, while consuming ≥ 4 units/week of alcohol was associated with worse periodontal indices, respectively (p < 0.05 in all cases). In contrast, coffee consumption rates and vitamin supplementation status had no significant effect on oral health status indicators. Conclusions: Our study highlights the overall poor oral health status of individuals affected by SCZ and the need for targeted preventive interventions.

Influence of residual pockets on periodontal tooth loss: A retrospective analysis.

BACKGROUND: Individuals enrolled in supportive periodontal therapy (SPT) can still present with tooth loss due to periodontitis (TLP). There is limited evidence on the influence of residual pockets (RPc) and a defined "threshold" at which a patient's profile is set to be at high risk for TLP in the literature. Therefore, this study aimed to assess the influence of RPc on TLP and determine the prognostic performance of RPc compared to the staging and grading of periodontitis on TLP risk. METHODS: Clinical data from 168 patients (3869 teeth) treated for periodontitis and receiving SPT for at least 10 years were evaluated in this retrospective study. TLP and the percentage of sites with RPc ≥ 5 mm or ≥6 mm per patient were collected. The prognostic performance of RPc was compared to the staging and grading of the disease on TLP using a multilevel Cox proportional hazard regression model. RESULTS: Over a median follow-up of 25 years, 13.7% of teeth were lost, 4.6% of which were due to periodontitis. Most patients with TLP had ≥1 site with RPc ≥5 mm (90.8%) or ≥6 mm (77.6%). Multivariate multilevel Cox regression revealed that patients with >15% of sites with RPc ≥5 mm had a hazard ratio of 2.34, and grade C had a hazard ratio of 4.6 for TLP compared to RPc ≤4 mm/grade A. Grading exhibited the best discrimination and model fit. CONCLUSION: Patients with RPc ≥5 mm at >15% of the sites are at risk for tooth loss. Grading and RPc ≥5 mm displayed very good predictive capability of TLP.

Self-Assessment of Hungarian Dentists Regarding Removable Partial Denture Design and Communication with the Dental Technician.

PURPOSE: To evaluate the extent to which dentists elaborate removable partial denture (RPD) design themselves and what they leave to the dental laboratory, as well as to assess the quality of information transferred to the technicians. MATERIALS AND METHODS: Data were collected using a questionnaire, and the responses of 211 dentists were analyzed. The categorized variables were analyzed using chi-square test and Fisher exact test. The significance level was considered as the standard P < .05. RESULTS: More than half (59.0%) of the dentists reported making an accurate, clear design for the dental technician before fabrication of the metal-framework RPD; 191 dentists (91.0%) specified the abutment teeth, 70.8% chose the type of clasps, and 60.7% gave instructions for the major connectors. The respondents largely took into account periodontal hygiene considerations (82.4%), and about one-third (37.7%) reported they were sending clear, precise instructions to the lab. The denture design was sent to the technician mainly (65.0%) in both drawing and text form. About half of the dentists (55.6%) gave only guidelines and left more details to be defined by the dental technician. Most dentists took responsibility in case of esthetic problems, irrespective of whether the dentist or technician prepared the denture design. CONCLUSION: Everyday practice concerning RPD design is far from the professional, legal, and ethical guidelines and rules relating to the duties and responsibilities of the dentist in relation to RPD design, and the situation therefore needs to be improved. Int J Prosthodont 2022;36:131-137. doi: 10.11607/ijp.7523.

Biomechanical Effects of Different Load Cases with an Implant-Supported Full Bridge on Four Implants in an Edentulous Mandible: A Three-Dimensional Finite Element Analysis (3D-FEA).

The long-term success and predictability of implant-supported restorations largely depends on the biomechanical forces (stresses) acting on implants and the surrounding alveolar bone in the mandible. The aim of our study was to investigate the biomechanical behavior of an edentulous mandible with an implant-supported full bridge on four implants under simulated masticatory forces, in the context of different loading schemes, using a three-dimensional finite element analysis (3D-FEA). A patient-specific 3D finite element model was constructed using pre- and post-implantation computer tomography (CT) images of a patient undergoing implant treatment. Simplified masticatory forces set at 300 N were exerted vertically on the denture in four different simulated load cases (LC1-LC4). Two sets of simulations for different implants and denture materials (S1: titanium and titanium; S2: titanium and cobalt-chromium, respectively) were made. Stress outputs were taken as maximum (Pmax) and minimum principal stress (Pmin) and equivalent stress (Peqv) values. The highest peak Pmax values were observed for LC2 (where the modelled masticatory force excluded the cantilevers of the denture extending behind the terminal implants), both regarding the cortical bone (S1 Pmax: 89.57 MPa, S2 Pmax: 102.98 MPa) and trabecular bone (S1 Pmax: 3.03 MPa, S2 Pmax: 2.62 MPa). Overall, LC1-where masticatory forces covered the entire mesio-distal surface of the denture, including the cantilever-was the most advantageous. Peak Pmax values in the cortical bone and the trabecular bone were 14.97-15.87% and 87.96-94.54% higher in the case of S2, respectively. To ensure the long-term maintenance and longevity of treatment for implant-supported restorations in the mandible, efforts to establish the stresses of the surrounding bone in the physiological range, with the most even stress distribution possible, have paramount importance.

Different Conical Angle Connection of Implant and Abutment Behavior: A Static and Dynamic Load Test and Finite Element Analysis Study.

Dental implants are artificial dental roots anchoring prosthetic restorations to replace natural teeth. Dental implant systems may have different tapered conical connections. Our research focused on the mechanical examination of implant-superstructure connections. Thirty-five samples with 5 different cone angles (24°, 35°, 55°, 75°, and 90°) were tested for static and dynamic loads, carried out by a mechanical fatigue testing machine. Fixing screws were fixed with a torque of 35 Ncm before measurements. For static loading, samples were loaded with a force of 500 N in 20 s. For dynamic loading, the samples were loaded for 15,000 cycles with a force of 250 ± 150 N. In both cases, the compression resulting from load and reverse torque was examined. At the highest compression load of the static tests, a significant difference (p = 0.021) was found for each cone angle group. Following dynamic loading, significant differences (p < 0.001) for the reverse torques of the fixing screw were also shown. Static and dynamic results showed a similar trend: under the same loading conditions, changing the cone angle-which determines the relationship between the implant and the abutment-had led to significant differences in the loosening of the fixing screw. In conclusion, the greater the angle of the implant-superstructure connection, the smaller the screw loosening due to loading, which may have considerable effects on the long-term, safe operation of the dental prosthesis.

Paclitaxel Protects against Isoproterenol-Induced Damage in Rat Myocardium: Its Heme-Oxygenase Mediated Role in Cardiovascular Research.

(1) Background: In cardiovascular applications, paclitaxel inhibits smooth muscle cell proliferation and migration and significantly reduces the occurrence of restenosis and target lesion revascularization. However, the cellular effects of paclitaxel in the myocardium are not well understood; (2) Methods: Wistar rats were divided into four groups: control (CTRL), isoproterenol (ISO) treated (1 mg/kg) and two groups treated with paclitaxel (PAC), which was administrated (10 mg/kg/day) for 5 days by gavage/per os alone or in combination (ISO + PAC) 3 weeks after ISO treatment. Ventricular tissue was harvested 24 h later for measurements of heme oxygenase (HO-1), reduced glutathione (GSH), oxidized glutathione (GSSG), superoxide dismutase (SOD), NF-κB, TNF-α and myeloperoxidase (MPO); (3) Results: HO-1 protein concentration, HO-1 activity, SOD protein concentration and total glutathione significantly decreased in response to ISO treatment. When PAC was administered in conjunction with ISO, HO-1, SOD concentration and total glutathione were not different from control levels. MPO activity, NF-κB concentration and TNF-α protein concentration were significantly increased in the ISO-only group, while the levels of these molecules were restored when PAC was co-administered; (4) Conclusions: Oral administration of PAC can maintain the expression of important antioxidants, anti-inflammatory molecules, HO-1, SOD and GSH, and suppress the production of TNF-α, MPO and NF-κB, which are involved in myocardial damage. The principal component of this cellular defense seems to be the expression of HO-1.