Evaluation of oxidative stress cycle in healthy and inflamed dental pulp tissue: a laboratory investigation

OBJECTIVES

The purpose of this study was to investigate the oxidative stress cycle consisting of reactive oxygen molecules (ROS), glutathione (GSH) and glutathione S-transferase (GST) in caries-related pulp inflammation.

METHODOLOGY

Fifty-four pulp tissue samples were collected from healthy donors with the diagnosis of reversible pulpitis, symptomatic irreversible pulpitis, and healthy pulp. Twelve pulp samples from each group were homogenized and total protein, ROS, GSH, and GST were measured by spectrophotometer. The remaining 6 samples from each group were prepared for paraffin block and used for the histopathologic and immunohistochemical evaluation of oxidative stress parameters and TUNEL labeling. Data were analyzed statistically.

RESULTS

The results revealed that total protein levels significantly decreased; however, ROS levels increased in both reversible and irreversible pulpitis compared to the healthy pulp (p < 0.01). Also, as inflammation increases, GST enzyme levels decrease while GSH levels increase significantly (p < 0.05). It was found that the number of TUNEL (+) cells was increased in irreversible pulpitis samples compared to healthy and reversible pulpitis groups (p < 0.05). GSTP1 and GSH immunoreactivity were also observed in irreversible pulpitis samples.

CONCLUSIONS

It has been revealed that caries-related inflammation alters the oxidative stress cycle in dental pulp tissue. The increase in GSH levels in the inflamed dental pulp due to the increase in ROS levels may improve the defensive ability of the dental pulp.

CLINICAL RELEVANCE

There is a relationship between oxidative stress and inflammation. Control of excessive oxidative stress in pulpitis can stimulate reparative and regenerative processes. The present findings may provide an overview of the management of oxidative stress in cases with pulpitis during regenerative treatments.

Prognosis and risk factors of nerve injuries in displaced pediatric supracondylar humerus fractures

Background

Supracondylar humerus (SCH) fractures are serious injuries due to the neighborhood of critical neural and vascular structures. One of the most devastating complications of SCH fractures is neurological damage, since it may cause permanent disability. The aim of this study is to categorize neurological complications, to report long-term functional outcomes, and to determine risk factors associated with childhood SCH fractures.

Methods

The records of 375 children were reviewed retrospectively. Data about amount and direction of displacement, the shape of the fracture, age at the time of fracture, gender, time from impaction to surgery, time of surgery, type of neurological injury, and recovery time were recorded.

Results

Neurological complications were seen in 37 (9.85%) children. Thirteen (35.1%) of the children had an iatrogenic nerve injury. All iatrogenic injuries were fully recovered in this study. However, 2 children who had combined neurological injury of radial, ulnar, and median nerves did not recover. Nearly 95% of all children who had neurological injury recovered fully. An anterior long and sharp bone fragment (spike) was observed in most of the children with neurological injury, and this spike was seen in 14 (58.3%) patients who had a trauma-related injury (n = 24).

Conclusion

The prognosis of these nerve injuries is excellent, especially the iatrogenic ones. A long and sharp bone fragment (spike) may be responsible for nerve injuries in some children. Surgical exploration is not necessary after an iatrogenic nerve injury when there is no neurotmesis. Patience and care are utmost needed to handle neurological complications.

Type I cardiorenal syndrome in patients with acutely decompensated heart failure: the importance of new renal biomarkers

OBJECTIVE

Type 1 cardiorenal syndrome (CRS) is an acute renal failure in patients with acute decompensated heart failure with an incidence of 24% to 45%. The aim of our study was to investigate the significance of new renal biomarkers to predict type 1 CRS.

PATIENTS AND METHODS

The study included 111 patients with acute decompensated heart failure diagnosed at the Istanbul Medical Faculty Emergency Department between 2014 and 2016, and 24 healthy volunteers. All urine samples were stored at -80°C after centrifugation. Samples were run according to the instructions of TIMP-2, ILGF-7, KIM-1, and IGFBP-7 ELISA kits. Diuretic treatments were then administered with intravenous administration of at least 80 mg furosemide per day. Follow-up biochemical and spot urine specimens were taken after 72 hours. For statistical analysis, SPSS version 21.0 statistical software was used. Significance was evaluated at p<0.05.

RESULTS

The baseline creatinine level was measured as 1.33 ± 0.39 mg/dL in the heart failure group. It was seen that 67% (75) of the patients had increased creatinine levels and developed type 1 CRS. ILGF-7, TIMP-2, and (ILGF-7 * TIMP-2) values were significantly higher in patients with cardiorenal syndrome when we separated the two groups as patients with and without cardiorenal syndrome (0.40 (0.25-0.71), p1: 0.049/2.40 (1.42-3.70), p2: 0.003/1.15 (0.29-2.43), p3: 0.001).

CONCLUSIONS

Renal tubular markers reveal promising developments in the pathophysiology of cardiorenal syndrome in light of recently obtained data. Renal tubular biomarkers may have the potential to be a predictor of heart failure and cardiorenal syndrome.

Laser-assisted management of ectopic eruption of permanent incisors

Ectopic eruption originates from the malpositioning of a tooth bud ending in the eruption of the tooth in an improper direction. This anomaly is a consequence of ectopic development of the tooth germ. This condition gives rise to significant aesthetic and occlusal issues in the early mixed dentition stage. The most frequently influenced teeth are the maxillary first molars, accompanied by the maxillary cuspids. Ectopic eruption is seldom seen and might derive from traumatic injury. In some cases, hyperplastic and fibrotic gingival tissue may lead to ectopic eruption of a permanent incisor. Managing ectopically erupting teeth generally rests on several reasons including extraction of supernumerary tooth, removal of cyst and excision of hyperplastic tissue and subsequent to orthodontic movement of tooth if necessary. In this case, the use of Er, Cr: YSGG lasers for the correction of hyperplastic soft tissues involving ectopically erupting permanent incisors are depicted considering two cases.

Measurement of dijet azimuthal decorrelation in pp collisions at [Formula: see text]

A measurement of the decorrelation of azimuthal angles between the two jets with the largest transverse momenta is presented for seven regions of leading jet transverse momentum up to 2.2[Formula: see text]. The analysis is based on the proton-proton collision data collected with the CMS experiment at a centre-of-mass energy of 8[Formula: see text] corresponding to an integrated luminosity of 19.7[Formula: see text]. The dijet azimuthal decorrelation is caused by the radiation of additional jets and probes the dynamics of multijet production. The results are compared to fixed-order predictions of perturbative quantum chromodynamics (QCD), and to simulations using Monte Carlo event generators that include parton showers, hadronization, and multiparton interactions. Event generators with only two outgoing high transverse momentum partons fail to describe the measurement, even when supplemented with next-to-leading-order QCD corrections and parton showers. Much better agreement is achieved when at least three outgoing partons are complemented through either next-to-leading-order predictions or parton showers. This observation emphasizes the need to improve predictions for multijet production.

Note: Effect of Some Spice Extracts on Bacterial Inhibition

Eighteen extracts of spices commonly consumed worldwide and grown naturally in Turkey were tested against twenty three bacterial strains to compare their antibacterial effects with eleven antibiotics. Eight pathogens and fifteen lactobacilli isolated from chick intestine were used as the test microorganisms. Pathogens (six different Staphylococcus aureus strains, Escherichia coli ATCC 25922 and Yersinia enterocolitica ATCC 1501) were grown in Nutrient broth and lactobacilli in MRS broth. Hop extracts formed inhibition zones against S. aureus strains of upto 36 mm. Inhibitory effects of hop extracts against S. aureuswere generally higher than that of erythromycin as antibiotic. Helichrysum compactum extract produced an inhibition zone of 23mm to E. coli ATCC 25922 and 26mm to Y. enterocolitica ATCC 1501. Helichrysum compactum extract inhibited the growth of Y. enterocolitica ATCC 1501 more than other spice extracts. While inhibition zones of these extracts against lactobacilli were found smaller than on S. aureus strains, inhibition zones of the same extracts against lactobacilli were found similar to those of E. coli ATCC 25922 and Y. enterocolitica ATCC 1501.

Search for direct pair production of supersymmetric top quarks decaying to all-hadronic final states in pp collisions at [Formula: see text]

Results are reported from a search for the pair production of top squarks, the supersymmetric partners of top quarks, in final states with jets and missing transverse momentum. The data sample used in this search was collected by the CMS detector and corresponds to an integrated luminosity of 18.9[Formula: see text] of proton-proton collisions at a centre-of-mass energy of 8[Formula: see text] produced by the LHC. The search features novel background suppression and prediction methods, including a dedicated top quark pair reconstruction algorithm. The data are found to be in agreement with the predicted backgrounds. Exclusion limits are set in simplified supersymmetry models with the top squark decaying to jets and an undetected neutralino, either through a top quark or through a bottom quark and chargino. Models with the top squark decaying via a top quark are excluded for top squark masses up to 755[Formula: see text] in the case of neutralino masses below 200[Formula: see text]. For decays via a chargino, top squark masses up to 620[Formula: see text] are excluded, depending on the masses of the chargino and neutralino.

Heart Rate Variability in Diabetes Patients

Diabetes mellitus can cause cardiovascular autonomic neuropathy and is associated with increased cardiovascular deaths. We investigated cardiovascular autonomic neuropathy in diabetics and healthy controls by analysis of heart rate variability. Thirty-one diabetics and 30 age- and sex-matched controls were included. In the time domain we measured the mean R-R interval (NN), the standard deviation of the R-R interval index (SDNN), the standard deviation of the 5-min R - R interval mean (SDANN), the root mean square of successive R - R interval differences (RMSSD) and the percentage of beats with a consecutive R - R interval difference > 50 ms (pNN50). In the frequency domain we measured high-frequency power (HF), low-frequency power (LF) and the LF/HF ratio. Diabetes patients had lower values for time-domain and frequency-domain parameters than controls. Most heart rate variability parameters were lower in diabetes patients with chronic complications than in those without chronic complications.

Measurement of Long-Range Near-Side Two-Particle Angular Correlations in pp Collisions at sqrt[s]=13 TeV

Results on two-particle angular correlations for charged particles produced in pp collisions at a center-of-mass energy of 13 TeV are presented. The data were taken with the CMS detector at the LHC and correspond to an integrated luminosity of about 270  nb^{-1}. The correlations are studied over a broad range of pseudorapidity (|η|<2.4) and over the full azimuth (ϕ) as a function of charged particle multiplicity and transverse momentum (p_{T}). In high-multiplicity events, a long-range (|Δη|>2.0), near-side (Δϕ≈0) structure emerges in the two-particle Δη-Δϕ correlation functions. The magnitude of the correlation exhibits a pronounced maximum in the range 1.0<p_{T}<2.0  GeV/c and an approximately linear increase with the charged particle multiplicity, with an overall correlation strength similar to that found in earlier pp data at sqrt[s]=7  TeV. The present measurement extends the study of near-side long-range correlations up to charged particle multiplicities N_{ch}∼180, a region so far unexplored in pp collisions. The observed long-range correlations are compared to those seen in pp, pPb, and PbPb collisions at lower collision energies.

Search for Narrow Resonances Decaying to Dijets in Proton-Proton Collisions at √[s]=13 TeV

A search for narrow resonances in proton-proton collisions at sqrt[s]=13  TeV is presented. The invariant mass distribution of the two leading jets is measured with the CMS detector using a data set corresponding to an integrated luminosity of 2.4  fb^{-1}. The highest observed dijet mass is 6.1 TeV. The distribution is smooth and no evidence for resonant particles is observed. Upper limits at 95% confidence level are set on the production cross section for narrow resonances with masses above 1.5 TeV. When interpreted in the context of specific models, the limits exclude string resonances with masses below 7.0 TeV, scalar diquarks below 6.0 TeV, axigluons and colorons below 5.1 TeV, excited quarks below 5.0 TeV, color-octet scalars below 3.1 TeV, and W^{'} bosons below 2.6 TeV. These results significantly extend previously published limits.

Measurement of the Top Quark Pair Production Cross Section in Proton-Proton Collisions at √[s]=13 TeV

The top quark pair production cross section is measured for the first time in proton-proton collisions at sqrt[s]=13  TeV by the CMS experiment at the CERN LHC, using data corresponding to an integrated luminosity of 43  pb^{-1}. The measurement is performed by analyzing events with at least one electron and one muon of opposite charge, and at least two jets. The measured cross section is 746±58(stat)±53(syst)±36(lumi)  pb, in agreement with the expectation from the standard model.

Event generator tunes obtained from underlying event and multiparton scattering measurements

New sets of parameters ("tunes") for the underlying-event (UE) modelling of the pythia8, pythia6 and herwig++ Monte Carlo event generators are constructed using different parton distribution functions. Combined fits to CMS UE proton-proton ([Formula: see text]) data at [Formula: see text] and to UE proton-antiproton ([Formula: see text]) data from the CDF experiment at lower [Formula: see text], are used to study the UE models and constrain their parameters, providing thereby improved predictions for proton-proton collisions at 13[Formula: see text]. In addition, it is investigated whether the values of the parameters obtained from fits to UE observables are consistent with the values determined from fitting observables sensitive to double-parton scattering processes. Finally, comparisons are presented of the UE tunes to "minimum bias" (MB) events, multijet, and Drell-Yan ([Formula: see text] lepton-antilepton+jets) observables at 7 and 8[Formula: see text], as well as predictions for MB and UE observables at 13[Formula: see text].

Scolicidal activity of taurolidine for the treatment of hydatid disease

OBJECTIVES

In this experimental study, we have evaluated in vivo and in vitro activities of taurolidine (TRD) against protoscolices of Echinococcus granulosus.

BACKGROUND

Scolicidal agent application is mandatory for the interventional treatment of hydatid cysts. Serious adverse effects of current scolicidal agents forced the scientist to search for less toxic chemicals.

METHODS

One milliliter of protoscolices suspension was administered into twelve Petri's dishes, six of them containing 5 ml of isotonic saline, and six of them containing 5 ml (5 mg/ml) TRD. Forty, male Balb/c mice were divided into five equal groups. Group 1: protoscolices inoculated group; Group 2: protoscolices inoculated and thereafter immediately administered with a single dose intravenous (IV) 0.5 ml TRD (400 mg/kg); Group 3: protoscolices inoculated and thereafter immediately administered with a single dose intraperitoneal (IP) 0.5 ml TRD (400 mg/kg); Group 4: three months after inoculating the protoscolices, one day before the sacrifice single dose IV 0.5 ml TRD (400 mg/kg) administered; Group 5: three months after inoculating the protoscolices, one day before the sacrifice single dose IP 0.5 ml TRD (400 mg/kg) administered.

RESULTS

All the protoscolices were dead in TRD-added Petri's Dishes in 90 minutes. In group 2 and group 3, no mouse had an intraabdominal hydatid cyst.

CONCLUSION

The results of this study are encouraging us to suggest TRD as an alternative scolicidal agent. Further clinical studies are needed to define the effectiveness and the mode of application of TRD for the treatment of hydatid disease (Tab. 1, Fig. 4, Ref. 30).

Influence of acid-etching and ceramic primers on the repair of a glass ceramic

The objective of this study was to evaluate the influence of different primers on the microtensile bond strength (μTBS) between a feldspathic ceramic and two composites. Forty blocks (6.0 x 6.0 x 5.0 mm³) were prepared from Vita Mark II . After polishing, they were randomly divided into 10 groups according to the surface treatment: Group 1, hydrofluoric acid 10% (HF) + silane; Group 2, CoJet + silane; Group 3, HF + Metal/Zirconia Primer; Group 4, HF + Clearfil Primer; Group 5, HF + Alloy Primer; Group 6, HF + V-Primer; Group 7, Metal/Zirconia Primer; Group 8, Clearfil Primer; Group 9, Alloy Primer; Group 10, V-Primer. After each surface treatment, an adhesive was applied and one of two composite resins was incrementally built up. The sticks obtained from each block (bonded area: 1.0 mm² ± 0.2 mm) were stored in distilled water at 37 degrees C for 30 days and submitted to thermocycling (7,000 cycles; 5 degrees C/55 degrees C ± 1 degree C). The μTBS test was carried out using a universal testing machine (1.0 mm/min). Data were analyzed using ANOVA and a Tukey test (a = 0.05). The surface treatments significantly affected the results (P < 0.05); no difference was observed between the composites (P > 0.05). The bond strength means (MPa) were as follows: Group 1a = 29.6; Group 1b = 33.7; Group 2a = 28.9; Group 2b = 27.1; Group 3a = 13.8; Group 3b = 14.9; Group 4a = 18.6; Group 4b = 19.4; Group 5a = 15.3; Group 5b = 16.5; Group 6a = 11; Group 6b = 18; Groups 7a to 10b = 0. While the use of primers alone was not sufficient for adequate bond strengths to feldspathic ceramic, HF etching followed by any silane delivered higher bond strength.

Effect of silane coupling agents and alloy primers on adhesion to titanium

AIM

Titanium-ceramic adhesion is known to be not ideal yielding to ceramic fractures especially in extensive implant reconstructions. Intraoral repair actions could be performed chairside using adhesion promoters. This study evaluated the adhesion of resin composite to titanium alloy using different silane coupling agents and alloy primers in combination with surface conditioning methods after aging.

METHODS

Titanium alloy disks were embedded in PMMA and wet polished to 1200 grit silicon carbide abrasive. Silanes and alloy primers used in combination with surface conditioning methods were as follows: 1) Al2O3 (50 µm) and Alloy Primer (Kuraray); 2) Al2O3 (50 µm) and V-Primer (Sun Medical); 3) SiO2 (30 µm) and Silane (ESPE-Sil) (CoJet System, 3M ESPE); 4) Al2O3 (50 µm) and Silane (ESPE-Sil); 5) Al2O3 (50 µm) and Cesead II Opaque Primer (Kuraray); 6) Al2O3 (50 µm) and Alloy Primer and Clearfil SE Bond Primer and Clearfil Porcelain Bond Activator (Clearfil Repair System, Kuraray). A thin layer of Sinfony opaquer was then applied, polymerized and a direct resin composite (Quadrant Photoposterior, Cavex) was adhered onto the conditioned titranium surfaces using polyethylene molds. After thermocycling (6000 cycles at 5-55 °C), specimens were submitted to shear loading in the Universal Testing Machine (crosshead speed: 1 mm/min). Failure types were classified as adhesive, cohesive in resin and a combination of adhesive and cohesive failures (mixed) after debonding. The data (MPa) were analyzed statistically using One-way ANOVA and Tukey's tests.

RESULTS

Significant difference was observed between the groups (P<0.05) (1-way ANOVA). Significantly higher results were obtained from Groups 1 (25.4±7) and 6 (26.3±5) than those of other groups (11.4±3 - 22.6±9) (P<0.05) (Tukeys' test). Group 2 presented the lowest mean bond strength among all groups (11.4±3) (P<0.05). While Group 1 showed mainly cohesive (4 out of 10) and mixed failures (6 out of 10) and no adhesive failures, other groups presented mainly adhesive and mixed failures.

CONCLUSION

Conditioning titanium surfaces with 50 µm Al2O3 followed by Alloy Primer or silane mixture of Clearfil Repair system delivered the most stable repair bond strength of the resin composite to titanium compared to other alloy primers and silanes tested.

The effect of dentin desensitizer on shear bond strength of conventional and self-adhesive resin luting cements after aging

This study tested the impact of Gluma Desensitizer on the shear bond strength (SBS) of two conventional (RelyX ARC, Panavia 21) and two self-adhesive (RelyX Unicem, G-Cem) resin luting cements after water storage and thermocycling. Human third molars (N=880) were embedded in acrylic resin. The buccal dentin was exposed. Teeth were randomly divided into four main groups, and the following cements were adhered: 1) RelyX ARC, 2) Panavia 21, 3) RelyX Unicem, and 4) G-Cem. In half of the teeth in each group, dentin was treated with Gluma Desensitizer. In the conventional cement groups, the corresponding etchant and adhesive systems were applied. SBS of the cements was tested after 1 hour (initial); at 1, 4, 9, 16, and 25 days of water storage; and at 1, 4, 9, 16, and 25 days of thermocycling. SBS data were analyzed by one-way analysis of variance (ANOVA); this was followed by the post hoc Scheffé test and a t-test. Overall, the highest mean SBS (MPa) was obtained by RelyX ARC (ranging from 14.6 ± 3.9 to 17.6 ± 5.2) and the lowest by Panavia 21 in combination with Gluma Desensitizer (ranging from 0.0 to 2.9 ± 1.0). All tested groups with and without desensitizer showed no significant decrease after aging conditions compared with baseline values (p>0.05). Only the Panavia 21/Gluma Desensitizer combination showed a significant decrease after 4 days of thermocyling compared with initial values and 1 day thermocycling. Self-adhesive cements with Gluma Desensitizer showed increased SBS after aging conditions (ranging from 7.4 ± 1.4 to 15.2 ± 3) compared with groups without desensitizer (ranging from 2.6 ± 1.2 to 8.8 ± 2.9). No cohesive failures in dentin were observed in any of the test groups. Although self-adhesive cements with and without desensitizer presented mainly adhesive failures after water storage (95.8%) and thermocyling (100%), conventional cement (RelyX ARC) showed mainly mixed failures (90.8% and 89.2%, after water storage and thermocyling, respectively). Application of the Gluma Desensitizer to dentin before cementation had a positive effect on the SBS of self-adhesive cements.

Silica coating on alumina ceramic: comparison of three chairside air-abrasion devices working for different times and distances

AIM

This study evaluated, by scanning electron microscope (SEM) and EDS, the effect of different strategies for silica coating (sandblasters, time and distance) of a glass-infiltrated ceramic (In-Ceram Alumina).

METHODS

Forty-one ceramic blocks were produced. For comparison of the three air-abrasion devices, 15 ceramic samples were divided in three groups (N.=5): Bioart, Microetcher and Ronvig (air-abrasion parameters: 20 s at a distance of 10 mm). For evaluation of the time and distance factors, ceramic samples (N.=5) were allocated in groups considering three applied times (5 s, 13 s and 20 s) and two distances (10 mm and 20 mm), using the Ronvig device. In a control sample, no surface treatment was performed. After that, the micro-morphologic analyzes of the ceramic surfaces were made using SEM. EDS analyzes were carried out to detect the % of silica on representative ceramic surface. ANOVA and Tukey tests were used to analyze the results.

RESULTS

One-way ANOVA showed the silica deposition was different for different devices (P=0.0054). The Ronvig device promoted the highest silica coating compared to the other devices (Tukey test). Two-way ANOVA showed the distance and time factors did not affect significantly the silica deposition (application time and distance showed no statistical difference).

CONCLUSION

The Ronvig device provided the most effective silica deposition on glass-infiltrated alumina ceramic surface and the studied time and distance for air-abrasion did not affect the silica coating.

Percutaneous Kirschner Wire fixation in distal radius metaphyseal fractures in children: does it change the overall outcome?

BACKGROUND AND OBJECTIVES

The aim of this study was to determine the effect of Kirschner wire fixation after closed reduction of radial metaphyseal fractures with high risk of redisplacement.

PATIENTS AND METHODS

In this retrospective study 40 cases were studied in two groups. In group 1 (n=20, average age 11.2 years), K-wire fixation was performed after closed reduction. In group 2 (n=20 average age 10.1 years), only plaster immobilization was applied following closed reduction. The compared clinical and radiological parameters were, pain, limb deformitiy, range of motion of the wrist, angulation of the fracture site, radial distal epipihyseal angle and severity of translation.

RESULTS

Redisplacement rate was 10% in group 1 and 50% in group 2. This shows, Kirschner wire fixation has a positive effect in the maintanence of the initial reduction (p<0.05). Age, gender, reduction quality had no effect on redisplacement (p>0.05). Concerning the severity of translation, the risk of redisplacement increases in stage 3 (50%- 100%) and stage 4 (>100%) fractures (p<0,05). Concomitant complete ulnar fracture has also redisplacement risk (p<0.05). Redisplacement risk increases when the distance of fracture line to epiphyseal line was between 11-20 mm (p<0.05). There was no significiant difference between two groups after last evaluation based on radiological parameters and clinical results (p>0.05).

CONCLUSIONS

This study shows that Kirschner wire fixation prevents redisplacement in early follow-up of first three weeks but there is no superiority after 20 months follow-up in distal metaphyseal fractures of children.

Effect of cyclic loading on fracture strength and microleakage of a quartz fiber dowel with different adhesive, cement and resin core material combinations

AIM

This study evaluated the performance of different adhesive-cement-core combinations coupled with quartz fiber dowels after cyclic loading and fracture strength tests and assessed the microleakage using dye penetration method.

METHODS

Forty maxillary canines (N=10 per group) were restored with fiber dowels (Quartz fiber DT Light Post) and four adhesive-cement-core material combinations (Group 1: All-Bond 2+C&B [root]/All-Bond 2+Biscore [core]; Group 2: All-Bond 2+Bisfil 2B [root]/All-Bond 2+Bisfil 2B [core]; Group 3: Scotchbond 1+RelyX ARC [root]/Scotchbond 1+Supreme [core]; Group 4: RelyX Unicem [root]/Scotchbond 1+Filtek Supreme [core]). The specimens were initially cyclic loaded (x2,000,000, 8 Hz, 3 to 100 N at 45 °C under 37±3 °C water irrigation) and then immersed in 0.5% basic fuchsine at 37 °C for 24 hours for dye penetration and interface failure detection. The failure surfaces were observed under the stereomicroscope (x100 magnification). Circumferential and centripetal dye penetration was scored at the buccal and lingual sites.

RESULTS

Only three specimens failed macroscopically during cyclic loading. No significant difference was found among the groups for the number of resisted cycles (P=0.9). Mean fracture strength between the groups were also not statistically significant (213±63-245±71 N) (P=0.740) (ANOVA). All four groups showed high values of dye penetration along the restoration interfaces being not significant from each other (P=0.224) (Kruskal-Wallis). The lingual sides of the teeth where the load applied, showed significantly higher incidence of detachment between the core and the dentin (100%, 90%, 100%, 90% for groups 1, 2, 3, 4, respectively) compared to the buccal side (30%, 30%, 60%, 40%) (P=0.032, c2 test). In 13 specimens (32.5%) crack lines at the coronal area were observed. Fracture strength was not significantly correlated with dye penetration (P=0.1803, r=-0.2162, Linear Regression and Correlation test).

CONCLUSION

Different combinations of adhesive-cement-composite core materials for the fiber post tested performed similar under cyclic loading and fracture strength tests.

Durability of feldspathic veneering ceramic on glass-infiltrated alumina ceramics after long-term thermocycling

AIM

This study compared the bond strength durability of a feldspathic veneering ceramic to glass-infiltrated reinforced ceramics in dry and aged conditions.

METHODS

Disc shaped (thickness: 4 mm, diameter: 4 mm) of glass-infiltrated alumina (In-Ceram Alumina) and glass-infiltrated alumina reinforced by zirconia (In-Ceram Zirconia) core ceramic specimens (N=48, N=12 per groups) were constructed according to the manufacturers' recommendations. Veneering ceramic (VITA VM7) was fired onto the core ceramics using a mold. The core-veneering ceramic assemblies were randomly divided into two conditions and tested either immediately after specimen preparation (Dry) or following 30000 thermocycling (5-55 ºC±1; dwell time: 30 seconds). Shear bond strength test was performed in a universal testing machine (cross-head speed: 1 mm/min). Failure modes were analyzed using optical microscope (x20). The bond strength data (MPa) were analyzed using ANOVA (α=0.05).

RESULTS

Thermocycling did not decrease the bond strength results for both In-Ceram Alumina (30.6±8.2 MPa; P=0.2053) and In-Ceram zirconia (32.6±9 MPa; P=0.3987) core ceramic-feldspathic veneering ceramic combinations when compared to non-aged conditions (28.1±6.4 MPa, 29.7±7.3 MPa, respectively). There were also no significant differences between adhesion of the veneering ceramic to either In-Ceram Alumina or In-Ceram Zirconia ceramics (P=0.3289). Failure types were predominantly a mixture of adhesive failure between the veneering and the core ceramic together with cohesive fracture of the veneering ceramic.

CONCLUSION

Long-term thermocycling aging conditions did not impair the adhesion of the veneering ceramic to the glass-infiltrated alumina core ceramics tested.

Orexins Activates Protein Kinase C-Mediated Ca2+ Signaling in Isolated Rat Primary Sensory Neurons

Previous results have suggested that orexins causes a rise of intracellular free calcium ([Ca2+]i) in cultured rat dorsal root ganglion (DRG) neurons, implicating a role in nociception, but the underlying mechanism is unknown. Hence, the aim of the present study was to investigate whether the orexins-mediated signaling involves the PKC pathways in these sensory neurons. Cultured DRG neurons were loaded with 1 μmol Fura-2 AM and [Ca2+]i responses were quantified by the changes in 340/380 ratio using fluorescence imaging system. The orexin-1 receptor antagonist SB-334867-A (1 µM) inhibited the calcium responses to orexin-A and orexin-B (59.1±5.1 % vs. 200 nM orexin-A, n=8, and 67±3.8 % vs. 200 nM orexin-B, n=12, respectively). The PKC inhibitor chelerythrine (10 and 100 µM) significantly decreased the orexin-A (200 nM)-induced [Ca2+]i increase (59.4±4.8 % P<0.01, n=10 and 4.9±1.6 %, P<0.01, n=9) versus response to orexin-A). It was also found that chelerythrine dose-dependently inhibited the [Ca2+]i response to 200 nM orexin-B. In conclusion, our results suggest that orexins activate intracellular calcium signaling in cultured rat sensory neurons through PKC-dependent pathway, which may have important implications for nociceptive modulation and pain.

Fracture strength of endodontically-treated teeth restored with post and cores and composite cores only

This study compared the fracture strength of different conditioned metallic posts, fiber-reinforced-composite posts and composite cores only in teeth without coronal tooth structure and determined failure modes after the fracture test. Post spaces were prepared in the root canals, and the teeth were randomly divided into seven experimental groups: Gr1: Titanium posts (ParaPost) + Silano-Pen (Bredent) + silane; Gr2: Titanium posts + 30 microm CoJet-Sand (3M ESPE) + silane; Gr3: Titanium posts + 50 microm Al2O3 + V-primer (Sun Medical); Gr4: Titanium posts + 50 microm Al2O3 + Alloy primer (Kuraray); Gr5: E-glass FRC post (EverStick); Gr6: Polyethylene fiber (Ribbond) + Resin impregnation and Gr7: Resin composite core only, with no posts. The posts were cemented using Panavia F 2.0 (Kuraray); coronal parts of the roots were etched, primed, bonded and composite cores were built-up. After thermocycling (5 degrees C-55 degrees C, 6000x), the fracture strength test was performed. The fracture strength of titanium posts (408 +/- 122 - 550 +/- 149 N) was significantly higher (p<0.05) than that of FRC posts (321 +/- 131 and 267 +/- 108 N for Everstick and Ribbond, respectively) or the group without posts (175 +/- 70 N) (Gr7) (ANOVA, Tukey's test). The group without posts resulted in complete core detachment (100%). In the E-glass FRC group, 60% adhesive core fracture occurred, covering >1/3 of the core and, in the polyethylene FRC group, 100% post-core detachment at the canal opening was observed. In all the titanium post applied groups (Gr1-Gr4), the posts remained in place with partial detachment of the core material from the post surface at varying degrees, depending on the conditioning method used. When no coronal tooth structure exist, the metal posts showed higher fracture strength values as opposed to the FRC post or no-post approach.

5-azacytidine treatment results in myelodysplastic syndrome

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Background: Myelodysplastic syndrome (MDS) is a clonal disease of hematopoiesis characterized by dysplasia in one or more series. 5-azacytidine (5-AZA) which is one of the methyl transferase inhibitors, targets the epigenetic changes in MDS and has been used for the last few years. Phase III studies which compare 5-AZA with supportive therapies report response rates up to 60%. Methods: In this study the aim was to retrospectively analyze the response rates of 26 MDS patients who were treated with 5-AZA between years 2002–2008. The patients were; median age 58 (21–84); male/female = 16/10; RAEB-I (7 patients); RAEB-II (18 patients); ve CMML (1 patient); secondary MDS (2 patients). According to an international prognostic scoring system, 6 patients were intermediate-1; 9 patients were intermediate-2; and 11 patients were high risk. Nine patients received 5-AZA as first-line therapy. The median leukocyte counts, absolute neutrophil counts (ANC), hemoglobin values, and thrombocyte counts at the begining of the cycles were; 2.4 (0.5–23)x10e9/L, 0.7 (0.1–16.5)x10e9/L, 8.6(5.3–11.4) gr/dl, 41(4–35)x10e9/L, respectively. The karyotype analysis revealed del5q in 3 patients; -7/del7q in 6 patients; trisomy 8 in 7 patients, del20q, del11q and complex karyotype (del7q+del5q+delY) in 1 patient each. The median cycles completed were 2 (1–6). Results: Seven patient were not elligible for response evaluation. Nine patients (47%) did not respond to the therapy and 8 of them were lost. Ten patients (53%) responded to the therapy with complete remission (n=4), partial remission (n = 2) and hematological improvement (n = 4). The responders and non-responders were similar in terms of median age, sex and pretreatment leukocyte, ANC and hemoglobin levels. However, there was statistically significant difference in terms of initial thrombocyte counts, total number of cycles received and serum ferritin levels. The patients who received 5-AZA as first line therapy had beter response than others (71% versus 29%). Conclusions: The observed response to 5-AZA therapy was similar to the reported rates in the literature. The most important factors for response were initial thrombocyte counts, total number of cycles, other therapies received before 5-AZA and the serum ferritin levels.

No significant financial relationships to disclose.

Effect of left atrial size and function on P-wave dispersion: a study in patients with paroxysmal atrial fibrillation

BACKGROUND

Paroxysmal atrial fibrillation (PAF), a common arrhythmia, is caused by the fractionated and nonhomogeneous propagation of sinus impulse.

HYPOTHESIS

This study was undertaken to examine the effect of left atrial (LA) dimension and function on P-wave dispersion (deltaP) in unselected patients with PAF and health controls.

METHOD

In this study, 62 consecutive patients with PAF (32 men, 30 women, mean age 55+/-11 years) and 62 age- and gender-matched healthy controls (33 men, 29 women, mean age 52+/-13 years) were studied to compare the effect of LA size, volume, and function on deltaP (difference between maximum and minimum P-wave duration on 12-lead electrocardiogram).

RESULTS

P-wave dispersion in patients with PAF and normal LA diastolic diameter (LAD) was longer than that in controls with normal LA size (53+/-8 vs. 34+/-8 ms, p < 0.001). P-wave dispersion increased in patients with PAF (62+/-12 vs. 53+/-8 ms, p = 0.003) and controls (40+/-7 vs. 34+/-8 ms, p = 0.005) with increased LAD. Presence or absence of PAF did not interact with LAD for their effect on deltaP (2 x 2 analysis of variance test p = 0.20). In the PAF group, deltaP correlated with LAD (r = 0.43, p = 0.002), LA diastolic volume (r = 0.6, p < 0.001), and LA ejection fraction (AEF) (r = - 0.33, p = 0.05). The AEF was preserved when LAD increased in the patients without PAF (0.52+/-0.07 vs. 0.57+/-0.10, p = NS), however was significantly decreased in the PAF group (0.37+/-0.12 vs. 0.49+/-0.10, p = 0.01). On multivariate logistic regression analysis, only deltaP retained significance on development of PAF.

CONCLUSION

It was concluded that deltaP increased in patients with PAF and normal LA size. In controls with increased LA size, deltaP increased but did not reach the levels attained in patients with PAF. The AEF was decreased in patients with PAF but was preserved in those without PAF. These findings can be explained by the changes in LA microarchitecture which concurrently decreased atrial myocardial contraction, increased deltaP, and predisposed to PAF.