In vitro performance of self-adhesive resin cements for post-and-core build-ups: Influence of chewing simulation or 1-year storage in 0.5% chloramine solution

The aim of this investigation was to test the in vitro performance of a self-adhesive resin composite core build-up in comparison with two typical conventional etch-and-rinse composite core build-up materials, before and after 1 year of storage in 0.5% chloramine solution (LTS). Sixty human maxillary central incisors were divided into three groups. Teeth were root filled and decoronated. Specimens were restored using glass fiber posts cemented with a self-adhesive resin cement. Core build-ups were made with a self-adhesive (U) and two core build-up materials (C and L) applied with their corresponding bonding systems. All specimens received adhesively luted lithium disilicate crowns. Ten specimens of each group were exposed to LTS and examined monthly for cracks or other alterations. All specimens were thermocycled, mechanically loaded (TCML) and finally loaded until failure occurred. There was no statistical significant difference in regard to the number of failures during TCML without and with LTS (log rank: p = 0.225 and 0.609, respectively). The median fracture load values after static loading without LTS and with LTS did not differ significantly (Kruskal–Wallis test: p = 0.057 and 0.106, respectively), though the fracture patterns between the groups without (p = 0.024) and with LTS (p = 0.027) did. Self-adhesive cements used for core build-up have no significantly higher risk of failure compared to conventional core build-up materials in both LTS and TCML test scenarios.     

Bone attachment to glass-fibre-reinforced composite implant with porous surface

A method has recently been developed for producing fibre-reinforced composites (FRC) with porous surfaces, intended for use as load-bearing orthopaedic implants. This study focuses on evaluation of the bone-bonding behaviour of FRC implants. Three types of cylindrical implants, i.e. FRC implants with a porous surface, solid polymethyl methacrylate (PMMA) implants and titanium (Ti) implants, were inserted in a transverse direction into the intercondular trabeculous bone area of distal femurs and proximal tibias of New Zealand White rabbits. Animals were sacrificed at 3, 6 and 12 weeks post operation, and push-out tests (n = 5–6 per implant type per time point) were then carried out. At 12 weeks the shear force at the porous FRC–bone interface was significantly higher (283.3 ± 55.3 N) than the shear force at interfaces of solid PMMA/bone (14.4 ± 11.0 N; p < 0.001) and Ti/bone (130.6 ± 22.2 N; p = 0.001). Histological observation revealed new bone growth into the porous surface structure of FRC implants. Solid PMMA and Ti implants were encapsulated mostly with fibrous connective tissue. Finite element analysis (FEA) revealed that porous FRC implants had mechanical properties which could be tailored to smooth the shear stress distribution at the bone–implant interface and reduce the stress-shielding effect.     

Predicting time-dependent remodeling of bone around immediately loaded dental implants with different designs

The purpose of this study was to predict time-dependent biomechanics of bone around cylindrical screw dental implants with different macrogeometric designs under simulated immediate loading condition. The remodeling of bone around a parallel-sided and a tapered dental implant of same length was studied under 100 N oblique load by implementing the Stanford theory into three-dimensional finite element models. The results of the analyses were examined in five time intervals consisting loading immediately after implant placement, and after 1, 2, 3 and 4 weeks following implantation. Maximum principal stress, minimum principal stress, and strain energy density in peri-implant bone and displacement in x-(implant lateral direction with a projection of the oblique force) and y-(implant longitudinal direction) axes of the implant were evaluated. The highest value of the maximum and minimum principal stresses around both implants increased in cortical bone and decreased in trabecular bone. The maximum and minimum principal stresses in cortical bone were higher around the tapered cylindrical implant, but stresses in the trabecular bone were higher around the parallel-sided cylindrical implant. Strain energy density around both implants increased in cortical bone, slightly decreased in trabecular bone, and higher values were obtained for the parallel-sided cylindrical implant. Displacement values slightly decreased in time in x-axis, and an initial decrease followed by a slight increase was observed in the y-axis. Bone responded differently in remodeling for the two implant designs under immediate loading, where the cortical bone carried the highest load. Application of oblique loading resulted in increase of stiffness in the peri-implant bone.     

两种形态玻璃纤维根管桩修复残冠的2年随访

背景：临床上多采用平行或锥形玻璃纤维根管桩修复根管治疗后的残根残冠,但两种形态根管桩的临床效果还有待证实。 目的：评价残冠修复时使用平行及锥形玻璃纤维根管桩的临床疗效。 方法：选择残冠患者121例,共156颗患牙,经完善的根管治疗后采用掷硬币法随机分为两组,分别采用平行玻璃纤维根管桩与锥形玻璃纤维根管桩重建桩核,然后以全瓷或金属烤瓷冠修复。术后每半年复查1次,分别对修复体的稳固性、边缘密合性、牙周组织情况、咬合功能等方面进行临床评价,观察期为2年。 结果与结论：121例患者均完成2年的随访观察。平行玻璃纤维根管桩组根管桩自牙颈部折断1例,治疗成功率为98.7%;锥形玻璃纤维根管桩组根管桩折断1例,根管桩连同全冠完整脱落1例,经重新粘接后行使功能良好,治疗成功率为97.5%;两组间治疗成功率差异无显著性意义(P > 0.05)。说明两种形态的玻璃纤维根管桩均可取得令人满意的临床效果,但远期疗效尚有待进一步观察。     

Titanium phosphate glass microspheres for bone tissue engineering

We have demonstrated the successful production of titanium phosphate glass microspheres in the size range of ～10–200 μm using an inexpensive, efficient, easily scalable process and assessed their use in bone tissue engineering applications. Glasses of the following compositions were prepared by melt-quench techniques: 0.5P₂O₅–0.4CaO–(0.1 ? x)Na₂O–xTiO₂, where x = 0.03, 0.05 and 0.07 mol fraction (denoted as Ti3, Ti5 and Ti7 respectively). Several characterization studies such as differential thermal analysis, degradation (performed using a novel time lapse imaging technique) and pH and ion release measurements revealed significant densification of the glass structure with increased incorporation of TiO₂ in the glass from 3 to 5 mol.%, although further TiO₂ incorporation up to 7 mol.% did not affect the glass structure to the same extent. Cell culture studies performed using MG63 cells over a 7-day period clearly showed the ability of the microspheres to provide a stable surface for cell attachment, growth and proliferation. Taken together, the results confirm that 5 mol.% TiO₂ glass microspheres, on account of their relative ease of preparation and favourable biocompatibility, are worthy candidates for use as substrate materials in bone tissue engineering applications.     

Acute stress responses in salivary alpha-amylase predict increases of plasma norepinephrine

Current biobehavioral research increasingly employs salivary alpha-amylase (sAA) as a surrogate marker for sympathetic nervous system (SNS) activity. While different lines of evidence point to the validity of this assumption, the literature is inconsistent with regard to associations of sAA with well-established SNS indicators, such as plasma norepinephrine (NE) or epinephrine (E). Small samples as well as application of different stress paradigms might be responsible. This study therefore set out to examine the relation between stress-induced sAA activity with NE and E by exposing a larger and less constrained sample to an effective stress protocol. Sixty-six healthy participants (mean age 24.30 ± 4.24 yrs), including n = 40 women, n = 26 men, n = 18 oral contraceptive (OC) users, and n = 15 habitual smokers, were recruited and subjected to the Trier Social Stress Test (TSST). Saliva and blood samples were taken at four time points throughout the experiment for later analysis of sAA activity and NE/E concentration, respectively. As expected, sAA, NE, and E showed significant increases in response to the acute stress induction (all p < 0.001). Regression analyses (controlling for age, BMI, sex, smoking and OC) revealed that stress responses in sAA significantly predicted stress responses in NE (r = 0.326; p = 0.025). Interestingly, stress responses in E predicted NE to a lesser extend (β = 0.265; p = 0.064). E responses showed no association with sAA (β = 0.265; p = 0.064). Higher sAA levels were found in habitual smokers (F = 4.27; p = 0.043) and in individuals with lower BMI (F = 2.81; p = 0.099). In conclusion, current data clearly show an association between stress responses of sAA and plasma NE. This relationship is stronger than the association of norepinephrine and epinephrine responses, thus placing the predictive power of sAA well within the expected range for different SNS markers.     

Teaching clinicians practical genomic medicine: 7 years’ experience in a tertiary care center

PurposeIncreased implementation of complex genetic technologies in clinical practice emphasizes the urgency of genomic literacy and proficiency for medical professionals. We evaluated our genomic education model.MethodsWe assessed the 5-day, extended format program, encompassing lectures, videos, interactive tests, practice cases, and clinical exercises. Pre- and post questionnaires assessed knowledge change, using t-tests to compare groups. Satisfaction on program completion and after 3 years were evaluated. Implementation in other centers determined acceptability.ResultsDuring 2012–2018, 774 clinicians from multiple disciplines and career stages attended 35 programs; 334 (43%) attended the 5-day extended format. Evaluations showed significant improvement of genomic literacy (mean 15.05/100 points, p < 0.001). Residents initially had higher scores than specialists (pre: 66.3 ± 17.3 vs. 58.7 ± 16.6, respectively, p = 0.002); both significantly improved, with specialists “catching up” (post: 79.1 ± 17.2 vs. 75.7 ± 15.9, nonsignificant (NS)); there was a similar trend between fellows and subspecialists (pre: 70 ± 18 vs. 59.4 ± 16.4, respectively, p = 0.007; post: 78.6 ± 16.4 vs. 73.2 ± 17.7, respectively, NS). Younger specialists (≤10 years residency) had significantly higher pre- and post scores. Absolute improvement in scores did not depend on medical specialties.ConclusionOur program is effective in improving genomics literacy for clinicians, irrespective of career length or expertise, and could be a model for improving skills in practical genomics for all medical professionals.     

Influence of a zirconia sandblasting treated surface on peri-implant bone healing: An experimental study in sheep

A sandblasting process with round zirconia (ZrO₂) particles might be an alternative surface treatment to enhance the osseointegration of titanium dental implants. Our previous study on sheep compared smooth surface titanium implants (control) with implant surfaces sandblasted with two different granulations of ZrO₂. As the sandblasted surfaces proved superior, the present study further compared the ZrO₂ surface implant with other surface treatments currently employed: machined titanium (control), titanium oxide plasma sprayed (TPS) and alumina sandblasted (Al-SL) at different times after insertion (2, 4 and 12 weeks). Twelve sheep were divided into three groups of four animals each and underwent implant insertion in tibia cortical bone under general anaesthesia. The implants with surrounding tissues were subjected to histology, histomorphometry, scanning electron microscopy and microhardness tests. The experimentation indicated that at 2 weeks Zr-SL implants had the highest significant bone ingrowth (p < 0.05) compared to the other implant surfaces, and a microhardness of newly formed bone inside the threads significantly higher than that of Ti. The present work shows that the ZrO₂ treatment produces better results in peri-implant newly formed bone than Ti and TPS processing, whereas its performance is similar to the Al-SL surface treatment.     

Linear and non-linear analysis of heart rate variability in master athletes and healthy middle-aged non-athletes

The present study examined the autonomic cardiac modulation of veteran athletes by the use of traditional and modern methods of heart rate variability (HRV) analysis. Twenty-nine healthy male master soccer players were divided into two groups; group A consisted of fourteen participants (age 48.9 ± 5.8 years), who were engaged to regular aerobic exercise and group B of fifteen sedentary ones (age 50.8 ± 5.7 years). Sixteen age-matched non-athletes formed control group C. All participants underwent ambulatory 24-h continuous electrocardiogram monitoring for the calculation of time and frequency domain HRV indices. Additionally, Poincaré analysis SD₁ and SD₂ as well as multiresolution wavelet analysis σ_wav(16) and σ_wav(32) markers were calculated. Time-domain indices were significantly increased in group A compared to groups B and C. Group A presented greater values of SD₁ (by 43%, p < 0.01 and 34.4%, p < 0.05 than groups B and C respectively) and SD₂ (by 26% compared to B and by 34.1% to C, p < 0.05). Index σ_wav(16) was higher in group A than in B and C by 35.6% (p < 0.01) and 23.5% (p < 0.05) respectively and so did σ_wav(32) by 22% (p < 0.05) and 24% (p < 0.05). Strong correlations were reported among indices. In conclusion, physically active master athletes attain better cardiac autonomic activity than sedentary counterparts, as proved by the application of Poincaré and multiresolution wavelet analyses, which can be useful research tools of cardiac autonomic modulation in sports cardiology.     

Are we sure that Mobile Health is really mobile? An examination of mobile device use during two remotely-delivered weight loss interventions

BackgroundThe “m” in mHealth is often thought of as the ability to receive health information and monitor behaviors on the go. Little is known about how people actually use mobile vs. traditional access methods and if access method affects engagement and health outcomes.MethodsThis study examines the 3-month outcomes of two mobile weight loss interventions (Pounds Off Digitally (POD) and mobile POD (mPOD)) where participants were required to own a mobile device for study entry and received weight loss information via podcast. Only participants in both studies who were randomized to receive the same theory-based podcast (TBP) were used in this analysis. In POD, 41 participants were randomized to the TBP condition (37 to a control not included in this analyses). In mPOD, 49 participants were randomized to the TBP (n = 49) and 47 to the TBP + mobile group (a self-monitoring app and Twitter app for social support). The goal of this study is to examine how participants accessed study components and to examine how type of device impacts engagement and weight loss.ResultsExamining data from both studies in aggregate, despite a mobile delivery method, 58% of participants reported using a non-mobile device to access the majority of the podcasts (desktop computers), 76% accessed the podcasts mostly at their home or work, and 62% were mainly non-mobile (e.g., sitting at work) when listening. Examining objective download data for mPOD, 49% of downloads (2889/5944) originated from non-mobile delivery methods vs. mobile platforms (3055/5944). At 3 months, 55% of Twitter posts originated from the website (n = 665 posts) vs. a mobile app (n = 540; 45%). There was no difference in the number of podcasts participants reported listening to by device. There were more Twitter posts by mobile app users (51 ± 11) than Twitter website users (23 ± 6, p < 0.05). There was a trend (p = 0.055) in greater weight loss among mobile users for podcasts (−3.5 ± 0.5%) as compared to non-mobile users (−2.5 ± 0.5%). Weight loss was significantly greater in Twitter mobile app users (−5.6 ± 0.9%) than website users (−2.2 ± 0.5%, p < 0.01).ConclusionType of device used for podcast listening did not affect engagement but there was a trend toward greater weight loss among mobile users. Method of Twitter posting was associated with engagement and weight loss with mobile app users posting more to Twitter and losing more weight.     

Specifying the effects of physician's communication on patients’ outcomes: A randomised controlled trial

ObjectiveTo experimentally test the effects of physician's affect-oriented communication and inducing expectations on outcomes in patients with menstrual pain.MethodsUsing a 2 × 2 RCT design, four videotaped simulated medical consultations were used, depicting a physician and a patient with menstrual pain. In the videos, two elements of physician's communication were manipulated: (1) affect-oriented communication (positive: warm, emphatic; versus negative: cold, formal), and (2) outcome expectation induction (positive versus uncertain). Participants (293 women with menstrual pain), acting as analogue patients, viewed one of the four videos. Pre- and post video participants’ outcomes (anxiety, mood, self-efficacy, outcome expectations, and satisfaction) were assessed.ResultsPositive affect-oriented communication reduced anxiety (p < 0.001), negative mood (p = 0.001), and increased satisfaction (p < 0.001) compared to negative affect-oriented communication. Positive expectations increased feelings of self-efficacy (p < 0.001) and outcome expectancies (p < 0.001), compared to uncertain expectations, but did not reduce anxiety. The combination of positive affect-oriented communication and a positive expectation reduced anxiety (p = 0.02), increased outcome expectancies (p = 0.01) and satisfaction (p = 0.001).ConclusionBeing empathic and inducing positive expectations have distinct and combined effects, demonstrating that both are needed to influence patients’ outcomes for the best.Practice implicationsContinued medical training is needed to harness placebo-effects of medical communication into practice.     

Effort-reward imbalance,overcommitment, and cellular immune measures among white-collar employees

We investigated whether chronic job stress, i.e., effort-reward imbalance (ERI) and overcommitment is associated with cellular immunity among 190 male and 157 female white-collar daytime employees (mean age 38; range 22–69 years). Participants provided a blood sample for the measurement of circulating immune (natural killer (NK), B, and T) cell counts and NK cell cytotoxicity (NKCC) and completed a questionnaire survey during April to June 2002. Stepwise multiple linear regression analyses revealed that NK cells were associated with effort (β = −.230; p = .013), reward (β = .169; p = .047), and ERI (β = −.182; p = .047) scores but not with overcommitment in men; reward score was positively associated with NKCC (β = .167; p = .049) and inversely associated with B cells (β = −.181; p = .030). No significant associations were found in women. Although the picture remains less clear in women, our findings suggest a potential immunological pathway linking adverse working conditions and stress-related disorders in men.     

Depression,traumatic stress and interleukin-6

BackgroundRecent evidence indicates that various types of interactions between nervous and immune system are important in pathogenesis of depression. These findings show that a significant role in developing depression play pro-inflammatory cytokines that may mediate its psychological, and neurobiological manifestations. Great importance among these cytokine molecules plays interleukin-6 (IL-6). There is growing evidence that this inflammatory process related to depression may be influenced by psychological stress as well as organic inflammatory conditions. These findings suggest that specific influences related to traumatic stress and dissociation could be found in close relationship to increased level of cytokine IL-6.MethodsIn the present study we have performed psychometric measurement of depression (BDI-II), traumatic stress symptoms (TSC-40) and dissociation (DES, SDQ-20), and immunochemical measure of serum IL-6 in 40 inpatients with unipolar depression (mean age 42.3 ± 6.8).ResultsThe results show that IL-6 is significantly correlated to BDI-II (Spearman R = 0.47, p < 0.01), TSC-40 (Spearman R = 0.32, p < 0.05), SDQ-20 (Spearman R = 0.34, p < 0.05) but not to DES (Spearman R = 0.25, p = 0.11).ConclusionThe findings of the present study indicate that increased level of IL-6 in depression could be directly related to symptoms of traumatic stress and somatoform dissociation.     

Finite element analysis on the biomechanical stability of open porous titanium scaffolds for large segmental bone defects under physiological load conditions

Repairing large segmental defects in long bones caused by fracture, tumour or infection is still a challenging problem in orthopaedic surgery. Artificial materials, i.e. titanium and its alloys performed well in clinical applications, are plenary available, and can be manufactured in a wide range of scaffold designs. Although the mechanical properties are determined, studies about the biomechanical behaviour under physiological loading conditions are rare. The goal of our numerical study was to determine the suitability of open-porous titanium scaffolds to act as bone scaffolds. Hence, the mechanical stability of fourteen different scaffold designs was characterized under both axial compression and biomechanical loading within a large segmental distal femoral defect of 30 mm. This defect was stabilized with an osteosynthesis plate and physiological hip reaction forces as well as additional muscle forces were implemented to the femoral bone. Material properties of titanium scaffolds were evaluated from experimental testing. Scaffold porosity was varied between 64 and 80%. Furthermore, the amount of material was reduced up to 50%. Uniaxial compression testing revealed a structural modulus for the scaffolds between 3.5 GPa and 19.1 GPa depending on porosity and material consumption. The biomechanical testing showed defect gap alterations between 0.03 mm and 0.22 mm for the applied scaffolds and 0.09 mm for the intact bone. Our results revealed that minimizing the amount of material of the inner core has a smaller influence than increasing the porosity when the scaffolds are loaded under biomechanical loading. Furthermore, an advanced scaffold design was found acting similar as the intact bone.     

Serum paraoxonase 1 activity and oxidant/antioxidant status in Saudi women with polycystic ovary syndrome

Oxidative stress is considered to be implicated in the pathophysiology of polycystic ovary syndrome (PCOS). This study was designed to evaluate the paraoxonase 1 (PON1) activity and oxidant/antioxidant status in Saudi women with PCOS and its contribution to the risk of atherosclerosis.Lipid profile, hormonal parameters, serum PON1 activity and oxidant (malondialdehyde)/antioxidant (total antioxidant capacity (TAC) levels were analyzed in 35 patients with PCOS and 30 healthy controls using a spectrophotometric method; correlation analysis was made between these variables. Insulin resistance was calculated by homeostasis model assessment (HOMA-IR).Women with PCOS had significantly higher fasting insulin, HOMA-IR and LH levels than controls. Lipid profiles and free androgen index (FAI) were significantly higher in women with PCOS when compared with controls. Serum PON1 activity was lower in the PCOS group (161.2 ± 6.1 U/l vs. 217.6 ± 9.3 U/l, p < 0.001) compared with controls, whereas malondialdehyde levels were higher in the PCOS group (4.26 ± 0.18 nmol/ml vs. 1.37 ± 0.12 nmol/ml, p < 0.001) compared with controls. Total antioxidant capacity was lower in the PCOS group (0.88 ± 0.10 mmol Trolox/l vs. 1.63 ± 0.17 mmol Trolox/l, p < 0.001) compared with controls. In PCOS group, serum PON1 was positively correlated with HDL-C (r = 0.425, p < 0.05) and TAC (r = 0.582, p < 0.01) but inversely correlated with HOMA-R (r = ?0.54, p < 0.01), testosterone (r = ?0.672, p < 0.01), FAI (r = ?0.546, p < 0.01) and malondialdehyde (r = ?0.610, p < 0.01).In conclusion, our data indicate that PON1 activity and antioxidant status were significantly decreased in Saudi women with PCOS. Lower serum PON1 activity might contribute to the increased susceptibility for the development of atherosclerosis risk in Saudi women with PCOS. Therefore, measurement of serum PON1 activity may be of value in assessment of women at higher risk for development of atherosclerosis risk in PCOS. However, further studies with larger sample size are needed to verify these results, and to assess the efficacy of antioxidant therapy on these patients.     

Persistence of varicella-zoster virus viraemia in patients with herpes zoster

BackgroundHerpes zoster is caused by the reactivation of varicella-zoster virus from sensory neurons. The commonest complication following zoster is chronic pain termed post herpetic neuralgia.ObjectivesTo investigate the dynamics of VZV viraemia and viral load following the resolution of zoster and its relationship to PHN development.Study designBlood samples were collected at baseline, 1 month, 3 months and 6 month from a prospective study of 63 patients with active zoster. Quantification of VZV DNA in whole blood was performed using a real-time PCR assay.ResultsDuring acute zoster, all patients had detectable VZV DNA in their blood. VZV DNA remained detectable in the blood of 91% of patients at 6 months although levels declined significantly (p < 0.0001). A history of prodromal symptoms (p = 0.005) and severity of pain at baseline (p = 0.038) as well as taking antivirals (p = 0.046) and being immunocompromised (p = 0.043) were associated, with longer time to recovery from PHN. Viral DNA loads were consistently higher in patients with risk factors for PHN and higher viral DNA loads over time were associated with longer time to recovery (p = 0.058 overall and 0.038 in immunocompetent).ConclusionsBased on these observations we hypothesise that VZV replication persists following acute shingles and that higher viral DNA loads contribute to the risk factors for PHN.     

Low-dose 17-β-estradiol cream for vaginal atrophy in a cohort without prolapse: Serum levels and vaginal response including tissue biomarkers associated with tissue remodeling

ObjectivesDescribe the effect of 50 mcg vaginal 17-β-estradiol (E2) cream on vaginal maturation, serum estrogen levels, atrophic symptoms, and biomarkers of oxidative stress and tissue remodeling in postmenopausal women without prolapse.MethodsSeventeen women, 65 years or older, applied intravaginal E2 cream nightly for eight weeks, then twice weekly for eight weeks. Vaginal biopsies, serial blood draws, and atrophic symptoms were obtained at baseline, eight, and sixteen weeks. Changes in atrophic symptoms, vaginal maturation indices (VMI), and serum E2 were measured. Immunohistochemical staining characterized levels of transforming growth factor-beta (TGF-β), nuclear factor kappa B (NFKB), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), and thrombospondin (TSP).ResultsSerum E2 levels (pg/ml) were unchanged from baseline (mean (SD)) 7.7 (3.3) to eight 9.7 (5.7) and sixteen 8.7 (5.8) (p = 0.24) weeks. VMI (mean (SD)) improved from baseline 34.2 (18.3) to eight 56.7 (13.1) and sixteen 54.5 (11.3) (p < 0.001) weeks with no difference between eight and sixteen weeks. Vaginal dryness (p = 0.03) and itching (p = 0.02) improved. Tissue biomarker levels did not change (TGF-β p = 0.35, NFKB p = 0.74, eNOS p = 0.80, iNOS p = 0.24, TSP p = 0.80).DiscussionVaginal E2 improved atrophic symptoms and VMI without elevating serum E2. Tissue remodeling biomarkers did not change.