Prognostic value of preoperative immune-nutritional scoring systems in remnant gastric cancer patients undergoing surgery.

BACKGROUND: Remnant gastric cancer (GC) is defined as GC that occurs five years or more after gastrectomy. Systematically evaluating the preoperative immune and nutritional status of patients and analyzing its prognostic impact on postoperative remnant gastric cancer (RGC) patients are crucial. A simple scoring system that combines multiple immune or nutritional indicators to identify nutritional or immune status before surgery is necessary. AIM: To evaluate the value of preoperative immune-nutritional scoring systems in predicting the prognosis of patients with RGC. METHODS: The clinical data of 54 patients with RGC were collected and analyzed retrospectively. Prognostic nutritional index (PNI), controlled nutritional status (CONUT), and Naples prognostic score (NPS) were calculated by preoperative blood indicators, including absolute lymphocyte count, lymphocyte to monocyte ratio, neutrophil to lymphocyte ratio, serum albumin, and serum total cholesterol. Patients with RGC were divided into groups according to the immune-nutritional risk. The relationship between the three preoperative immune-nutritional scores and clinical characteristics was analyzed. Cox regression and Kaplan-Meier analysis was performed to analyze the difference in overall survival (OS) rate between various immune-nutritional score groups. RESULTS: The median age of this cohort was 70.5 years (ranging from 39 to 87 years). No significant correlation was found between most pathological features and immune-nutritional status (P > 0.05). Patients with a PNI score < 45, CONUT score or NPS score ≥ 3 were considered to be at high immune-nutritional risk. The areas under the receiver operating characteristic curves of PNI, CONUT, and NPS systems for predicting postoperative survival were 0.611 [95% confidence interval (CI): 0.460-0.763; P = 0.161], 0.635 (95%CI: 0.485-0.784; P = 0.090), and 0.707 (95%CI: 0.566-0.848; P = 0.009), respectively. Cox regression analysis showed that the three immune-nutritional scoring systems were significantly correlated with OS (PNI: P = 0.002; CONUT: P = 0.039; NPS: P < 0.001). Survival analysis revealed a significant difference in OS between different immune-nutritional groups (PNI: 75 mo vs 42 mo, P = 0.001; CONUT: 69 mo vs 48 mo, P = 0.033; NPS: 77 mo vs 40 mo, P < 0.001). CONCLUSION: These preoperative immune-nutritional scores are reliable multidimensional prognostic scoring systems for predicting the prognosis of patients with RGC, in which the NPS system has relatively effective predictive performance.

Effects of precementation on minimizing residual cement around the marginal area of dental implants.

STATEMENT OF PROBLEM: Residual cement is detrimental to the long-term success of dental implants with a cement-retained restoration. The complete elimination of excess cement remains a challenge. PURPOSE: The purpose of this in vitro study was to evaluate the effects of precementation technique on minimizing the residual cement and retention of restorations. MATERIAL AND METHODS: Four custom cobalt-chromium alloy (Co-Cr) abutments were manufactured by computer-aided design and computer-aided manufacturing (CAD-CAM) as precementation abutments with height and radius reductions of 25 µm (A25), 50 µm (A50), 75 µm (A75), and 100 µm (A100). Fifty CAD-CAM-fabricated standard Co-Cr abutments and corresponding crowns were randomly matched and treated as follows: 10 specimens were cemented with the conventional cementation procedure with glass ionomer cement (G0), and 40 were precemented with precementation abutments (n=10) before the definitive cementation with standard abutments (G25, G50, G75, G100). The weight of the cement in the cement space was calculated, and the marginal sealing was evaluated by using a stereoscopic microscope. The effects of precementation with resin cement on minimizing residual cement around the marginal area of dental implants were further evaluated extraorally. The influence of precementation with glass ionomer and resin cement on the retention force was analyzed by using a universal testing machine at a crosshead speed of 0.5 mm/min. One-way ANOVA was used to analyze cement mass and marginal sealing values. Two-way ANOVA was used to compare the retention forces (α=.05). RESULTS: The cement weight of G50 (7.2 ±0.6 mg) was significantly higher than that of G25 (6.0 ±1.1 mg, P<.05), while no significant differences in cement weights were found among G50, G75, and G100. Consistently, the G50, G75, and G100 had higher marginal sealing values than that of the G25 (P<.01). Extraoral experiments showed that the precementation with A50 reduced subgingival residual cement without affecting retention. CONCLUSIONS: These in vitro results suggest that precementation with a precisely manufactured precementation abutment minimized the residual cement around implant abutments, and 50 µm could be a preferable precementation space.

Lanthanoid tagging via an unnatural amino acid for protein structure characterization.

Lanthanoid pseudo-contact shift (PCS) provides long-range structural information between a paramagnetic tag and protein nuclei. However, for proteins with native cysteines, site-specific attachment may only utilize functional groups orthogonal to sulfhydryl chemistry. Here we report two lanthanoid probes, DTTA-C3-yne and DTTA-C4-yne, which can be conjugated to an unnatural amino acid pAzF in the target protein via azide-alkyne cycloaddition. Demonstrated with ubiquitin and cysteine-containing enzyme EIIB, we show that large PCSs of distinct profiles can be generated for each tag/lanthanoid combination. The DTTA-based lanthanoid tags are associated with large magnetic susceptibility tensors owing to the rigidity of the tags. In particular, introduction of the DTTA-C3 tag affords intermolecular PCSs and enables structural characterization of a transient protein complex between ubiquitin and a UBA domain. Together, we have expanded the repertoire of paramagnetic tags and the applicability of paramagnetic NMR.

Protein Structural Ensembles Visualized by Solvent Paramagnetic Relaxation Enhancement.

A protein can be in different conformations when fulfilling its function. Yet depiction of protein structural ensembles remains difficult. Here we show that the accurate measurement of solvent paramagnetic relaxation enhancement (sPRE) in the presence of an inert paramagnetic cosolute allows the assessment of protein dynamics. Demonstrated with two multi-domain proteins, we present a method to characterize protein microsecond-millisecond dynamics based on the analysis of the sPRE. Provided with the known structures of a protein, our method uncovers an ensemble of structures that fully accounts for the observed sPRE. In conjunction with molecular dynamics simulations, our method can identify protein alternative conformation that has only been theorized before. Together, our method expands the application of sPRE beyond structural characterization of rigid proteins and complements the established PRE NMR technique.

[Effect of occlusal reconstruction on cerebral blood flow and cerebral oxygen saturation in patients with malocclusion].

OBJECTIVE: To investigate the effect of occlusal reconstruction on blood flow velocity and cerebral oxygen saturation in patients with malocclusion. METHODS: Thirty-three patients with malocclusion treated with occlusal reconstruction in Department of Stomatology, Medical School of Huzhou Normal College from Feb 2011 to Oct 2013 were enrolled in the study. The systolic peak flow velocity (vs), end-diastolic peak flow (vd) , mean peak flow velocity (vm) of middle cerebral artery and the oxygen saturation (rScO2) in the brain were detected at rest or chewing status by using transcranial Doppler color ultrasonography and near-infrared spectroscopy, respectively. RESULTS: In rest state, vm was significantly increased on 3 months after treatment, while vs and vd were significantly increased on 6 months after treatment and rScO2 were increased on 12 months after treatment (P<0.05). In chewing state, vs, vm, and rScO2 were increased on 3 months after treatment, and vd was increased on 6 months after treatment (P<0.05). CONCLUSION: Occlusal reconstruction can increase blood flow velocity of middle cerebral artery and cerebral oxygen saturation and improve oxygen supply of the brain in patients with malocclusion.

Influence of casein phosphopeptide-amorphous calcium phosphate application, smear layer removal, and storage time on resin-dentin bonding.

The aim of this study is to evaluate the influence of Tooth Mousse (TM) application, smear layer removal, and storage time on resin-dentin microtensile bond strength (µTBS). Dentin specimens were divided into two groups: (1) smear layer covered; (2) smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive (Clearfil SE Bond (CSE); Kuraray Medical, Tokyo, Japan), an all-in-one adhesive (G-Bond (GB); GC Corp, Tokyo, Japan), and a total-etch adhesive (Adper Single Bond 2 (SB); 3M ESPE, St. Paul, MN, USA), the specimens were stored for 3 d or 6 months in deionized water at 37 °C, and µTBS was tested and analyzed. With the exception of SB (no TM application) and GB, the µTBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage (P≤0.001). Bond strength of GB decreased significantly when using EDTA (3 d storage, P<0.05). TM application only increased the µTBS of GB (no EDTA) and SB (with EDTA) after 3 d (P≤0.02). Comparing the adhesives after 3 d of storage, CSE exhibited the greatest µTBS values followed by GB and SB (P≤0.02). The factors of adhesive, EDTA, and TM did not show any significant impact on µTBS when specimens were stored for 6 months (P>0.05). The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on µTBS of dentin bonds after a period of 6 months.

A decadentate Gd(III)-coordinating paramagnetic cosolvent for protein relaxation enhancement measurement.

Solvent paramagnetic relaxation enhancement (sPRE) arises from random collisions between paramagnetic cosolvent and protein of interest. The sPRE can be readily measured, affording protein structure information. However, lack of an inert cosolvent probe may yield sPRE values that are not consistent with protein structure. Here we synthesized a new sPRE probe, triethylenetetraamine hexaacetate trimethylamide gadolinium, or Gd(III)-TTHA-TMA. With a total of 10 coordination sites, this paramagnetic cosovlent eliminates an inner-sphere water molecule that can otherwise transfer relaxation to protein through exchange. With the metal ion centered, the new probe is largely spherical with a radius of 4.0 Å, permitting accurate back calculation of sPRE. The effectiveness Gd(III)-TTHA-TMA as a sPRE probe was demonstrated on three well-studied protein systems.

Prosthodontic rehabilitation of malpositioned implants after ameloblastoma followed by mandibulectomy and costal bone graft: a clinical report.

This clinical report describes the rehabilitation with costal bone graft reconstruction and 3 implants of a patient with a partial mandibular defect as a result of a partial mandibulectomy due to ameloblastoma of the left mandible. Due to the altered shape of the graft bone, the implants were malpositioned in the buccolingual plane. The prosthodontic rehabilitation was successfully completed by using an implant-supported milled bar combined with telescopic crown-retained dentures. This tooth implant-supported prosthesis successfully restored function and esthetics. Aspects that deal with the repair of the buccal soft tissues are discussed.

Marginal and internal fit of two different zirconium copings fabricated on the implant abutment.

OBJECTIVE: To evaluate the accuracy of marginal and internal fit of the zirconium copings manufactured by two different computer-aided design(CAD)/computer-aided manufacturing(CAM)system on the implant abutment. METHODS: Using different scanning mode,five Procera(®) zirconium copings and five Lava zirconium copings were fabricated on the same implant abutment, and then compared with five precious metal copings fabricated by traditional method. Fifteen abutment replica were made with die-stone and the copings were randomly cemented on them, then they were sectioned and invested. The marginal, shoulder, occlusal, and axial fit of each sample was measured by scanning electron microscopy (SEM). RESULTS: There was no significant difference in marginal and axial fit among the three groups(P>0.05). Significant difference in occlusal fit was found among the three groups(P<0.05): Lava group showed better fit than the others(P<0.05)and Procera(®) group showed better fit than the control(P<0.05). CONCLUSIONS: These two types of zirconium coping have clinically acceptable marginal and internal fit. The internal fit of zirconium coping may be affected by different manufacturing techniques.

[Effect of different irrigants on radicular dentin cleansing and resin tag formation after post space preparation].

OBJECTIVE: To evaluate the effect of different root canal irrigants on smear layer removal and dentinal tubule opening of root canal surfaces after post space preparation. METHODS: Thirty maxillary anteriors were endodontically treated. After post space preparation, the teeth were assigned to three groups with ten teeth each: group A, B, C. 3% H2O2, 15% ethylenediamine tetraacetic acid(EDTA), 15% EDTA and 3% NaClO were used as irrigant of group A, B, C. After post space irrigation, eight teeth of each group were examined under scanning electron microscope (SEM) for smear layer removal and dentinal tubule opening. The left two specimens were restored with fiber posts and prepared for evaluation of resin tag formation. RESULTS: The cleansing effectiveness of group A, B and C was respectively 3.89 +/- 0.36, 1.77 +/- 0.30, 1.25 +/- 0.21. The dentinal tubule opening of group A, B and C was respectively (2.53 +/- 0.19), (3 11 +/- 023) (3.83 +/- 0.52) microm. The cleansing effectiveness and dentinal tubule opening of root canal surfaces were significantly affected by different root canal irrigants (P < 0.05). Excessive erosion of the dentin was observed in group C. Resin tag formation differed between the three irrigant groups, and group B showed excellent resin tag formation. CONCLUSION: Irrigation with 15% EDTA after post space preparation can excellently remove the smear layer and improve dentinal tubule opening, permitting well penetration of resin adhesive into the dentinal tubules and collagen fibrillar structure.

Does endodontic post space irrigation affect smear layer removal and bonding effectiveness?

The effect of different post space irrigants on smear layer removal and dentin bond strength was evaluated. Sixty-six extracted sound maxillary central incisors were endodontically treated. After post space preparation, the teeth were assigned to three groups of 22 teeth each. The teeth of these three groups were irrigated for 1 min with 17% ethylenediaminetetracetic acid (EDTA) (group 1), 5.25% sodium hypochlorite (NaOCl) (group 2), or 0.9% sodium chloride (NaCl) (group 3). In each group, eight specimens were split longitudinally for smear layer evaluation, and the other fourteen specimens were filled with a self-etching adhesive system (Panavia F). Four of 14 specimens of each group were prepared for evaluation of the resin-dentin interdiffusion zone (RDIZ) and resin tags, and the other 10 specimens were serially sectioned for push-out test analysis. Smear layer removal and bond strength were affected by different post space irrigants. EDTA removed the smear layer extremely effectively and, as a result, improved the bond strength at each region (apical, middle, and coronal) of the roots. Resin tag formation and the RDIZ were also affected by different irrigants and in accordance with bond strength. Therefore, removal of the smear layer use a self-etching luting system plays an important role in bonding effectiveness.

Effect of different irrigation on smear layer removal after post space preparation.

The purpose of this study was to evaluate the effect of different irrigating solutions on smear layer removal and dentinal tubule opening on root canal surfaces after post space preparation and to study whether additional ultrasonic irrigation has any effect on smear layer removal. Forty-eight anterior teeth were treated endodontically. After post space preparation, they were assigned to six groups: group 1, EDTA; group 2, EDTA with ultrasonic activation; group 3, sodium hypochlorite (NaOCl); group 4, NaOCl with ultrasonic activation; group 5, sodium chloride (NaCl); and group 6, NaCl with ultrasonic activation. Specimens were examined under a field-emission scanning electron microscope and scored for debris removal and dentinal tubule opening at the coronal, middle, and apical thirds of the root canal. The results showed that EDTA performed significantly better than NaCl and NaOCl in smear layer removal and dentinal tubule opening. Additional ultrasonic irrigation did not improve smear layer removal significantly.

[An experimental study on fracture resistance of metal-ceramic crowned incisors with different post-core systems].

OBJECTIVE: To evaluate fracture resistance of metal-ceramic crown restored incisors with different post-and-core systems. METHODS: Selected 40 intact maxillary central incisors were endodontically treated and then randomly assigned to four groups of 10 teeth each. Teeth in Group A were prepared to root canal with 10 mm in length, 1.6 mm in diameter and restored with fiber-reinforced posts and composite cores. Same final preparation but root canal with 1.5 mm in diameter was achieved for teeth in the other three groups. Teeth in Group B were restored with prefabricated titanium alloy posts and composite cores and teeth in Group C were restored with cast nickel-chromium post-cores. The posts were luted with a composite resin luting system, and metal-ceramic crowns were restored and cemented with the same luting system for all of the teeth in Group A, B and C. The other 10 teeth were restored with cast nickel-chromium post-cores and metal-ceramic crowns as a control, which were cemented with glass-ionomer cement. All restored teeth were thermo-cycled for 5000 cycles (5 degrees C/55 degrees C) as a fatigue test. The tooth was loaded in a universal testing machine at an angle of 135 degrees to the long-axis at the incisal edge with a cross-head speed of 1.5 mm/min until fracture. Fracture loads (N) and modes (repairable or catastrophic) were recorded. One-way ANOVA and SNK test were used to determine the significance of the failure loads between groups. Chi-square test was conducted for evaluation of the fracture mode. RESULTS: The fracture loads from Group A, B, C and control group were (534.4 +/- 145.7) N, (499.8 +/- 168.9) N, (412.6 +/- 99.3) N, (337.4 +/- 121.2) N, respectively. A significant difference was existed among four groups (P < 0.05). The fracture loads of Group A and Group B were significantly higher than control group (P < 0.05). The repairable mode of fracture observed from Group A to control group was 80%, 40%, 20% and 30%, Group A had a significantly higher number of repairable fractures than those of the other groups (P < 0.05). CONCLUSIONS: Within the limitations of this study, fiber-reinforced post has an excellent fracture resistance, and can be recommended as an alternative to cast post-cores, especially for incisor esthetic restoration.

Marginal discrepancies and leakage of all-ceramic crowns: influence of luting agents and aging conditions.

PURPOSE: This study evaluated the marginal discrepancies and leakage of all-ceramic crowns cemented with different luting agents after fatigue tests. MATERIALS AND METHODS: Forty-eight all-ceramic crowns were cemented onto natural molars. Zinc-phosphate cement, compomer cement, and an adhesive composite resin luting system were used in 16 specimens each. Sixteen metal-ceramic crowns were cemented with zinc-phosphate cement as a control. Half of the specimens in each group were fatigued in a chewing simulator for 600,000 loading cycles with 3,500 thermocycles. The others received the 3,500 thermocycles only. An impression-replica technique and SEM were used for evaluation of the marginal discrepancies. Leakage of the specimens was microscopically assessed. RESULTS: There were no significant differences between marginal discrepancies of the groups, with the exception of porcelain shoulder margins in the metal-ceramic group, which had significantly larger discrepancies (P < .01). There was no significant effect of the fatigue tests on marginal discrepancies. However, significant differences of leakage were found between the groups cemented with the different luting agents after both fatigue tests. The adhesive composite resin luting system demonstrated the least leakage. The compomer cement showed an intermediate level of leakage, and the zinc-phosphate cement showed severe leakage that extended through the dentinal tubules to the pulp chambers. No significantly different effect of the two fatigue tests on the leakage was found. CONCLUSION: The adhesive composite resin luting system showed clinically acceptable marginal discrepancies and an excellent ability to minimize leakage of all-ceramic crowns.

[A comparative study of marginal microleakage using three different cements in ceramic crowns]

OBJECTIVE: To evaluate the marginal microleakage of IPS-Empress 2 all-ceramic crowns using three different cements. METHODS: Twenty-four IPS-Empress 2 all-ceramic crowns were built and luted onto standardly prepared human upper third molars using three different cements. All samples were thermocycled then submerged in 2% fuchsin for 24 hours. The marginal microleakage at tooth-cement and ceramic crown-cement interfaces was observed using light stereomicroscopy. RESULTS: The Panavia F adhesive luting system demonstrated the least microleakage(0.90+/-0.75, 0.46+/-0.37). Dyract compomer cement showed an intermediate level of microleakage (4.71+/-1.68, 5.28+/-1.48). Harvard zinc phosphate cement was associated with severe microleakage in all specimens( 6.99+/-0.04, 6.99+/-0.04). THe differences in microleakage among the three cements was highly significant(P<0.01). CONCLUSION: Panavia F adhesive luting system was the most effective dental cement to prevent microleakage. It can be used for IPS-Empress 2 posterior all-ceramic crowns.