Enhanced Dynamics and Charge Transport at the Eutectic Point: A New Paradigm for the Use of Deep Eutectic Solvent Systems.

Deep eutectic solvents (DESs) are a class of versatile solvents with promise for a wide range of applications, from separation processes to electrochemical energy storage technologies. A fundamental understanding of the correlation among the structure, thermodynamics, and dynamics of these materials necessary for targeted rational design for specific applications is still nascent. Here, we employ differential scanning calorimetry (DSC), broadband dielectric spectroscopy (BDS), and femtosecond transient absorption spectroscopy (fs-TAS) to investigate the correlation among thermodynamics, dynamics, and charge transport in mixtures comprising a wide range of compositions of choline chloride (ChCl) and ethylene glycol (EG). Detailed analyses reveal that (i) the eutectic composition of this prototypical DES occurs in the 15-20 mol % ChCl in the EG range rather than the previously assumed 33 mol %, and (ii) both rotational dynamics and charge transport at the eutectic composition are enhanced in this composition range. These findings highlight the fundamental interplay between thermodynamics and dynamics in determining the properties of DESs that are relevant to many applications.

Prototyping of increased vertical dimension of occlusion using an existing removable partial denture and composite resin: a case report.

Full-mouth rehabilitation can be challenging due to the complexity of restoring the vertical dimension of occlusion (VDO) and replacing missing teeth. In partially edentulous patients, the concept of a bonded composite resin prototype for increasing the VDO has previously been applied through the use of an overlay removable partial denture (RPD) with acrylic resin covering the existing dentition. Unfortunately, this type of prosthesis does not always accurately model the function and phonetics intended for the definitive prostheses, and the esthetic result often is less than ideal. It would be advantageous if direct bonding could be used with the patient's existing RPD to model the increased VDO, but this approach has not been reported in the literature. This case report describes the direct bonding of an existing RPD to create a prototype for increased VDO in a partially edentulous patient with a skeletal Class II malocclusion. The successful outcome has been maintained for more than 1 year.

Complex filter removal using forceps from combined transfemoral and transjugular approach unhooking the filter apex using forceps and dual access: Two case reports.

Modern inferior vena cava filters (IVCFs) are intended to be retrieved once a thrombotic process or risk of pulmonary embolism has resolved independent of administration of anticoagulation. IVCF removal can be challenging with the risk of complications including venous perforation, filter migration, and device fracture. IVCF removal has been described using the nomenclature of routine versus advanced retrieval. Routine retrieval is defined as accessing the filter hook with a loop snare device before advancing a sheath over the filter. Advanced retrieval techniques are employed when routine retrieval fails and can refer to a variety of approaches, including filter realignment with loop snare, stiff wire-displacement, use of a wire and snare with dual access, angioplasty balloon advanced over a guidewire, single access sling approach, the sandwich technique, the endobronchial forceps dissection and removal, photothermic ablation with excimer laser, and the filter eversion technique among others. Successful routine retrieval of IVCF has been reported at 74% and IVCF retrieval with advanced techniques has a success rate of nearly 95%. The complication rate with advanced techniques is higher when compared with routine techniques (5.3% vs. 0.4%; p < .05) and, as expected, requires fluoroscopic time. We report two cases of advanced filter retrieval using endobronchial forceps simultaneously or sequentially through the transfemoral and trans-jugular approach.

24 hour polymerization shrinkage of resin composite core materials.

PURPOSE: The study's purpose was to evaluate the 24-hour polymerization shrinkage of resin composite core materials. MATERIAL AND METHODS: Eleven resin composite core material samples (n = 12) were evaluated using a non-contact imaging device with measurements obtained over 24 h. Shrinkage values were determined corresponding to proposed times involved with CAD/CAM same-day treatment and at 24 h. Shrinkage data was statistically compared using Friedman/Dunn's test for intragroup analysis and Kruskal Wallis/Dunn's test for intergroup analysis, all at a 95% level of confidence (α = 0.05). RESULTS: Mean results identified a wide volumetric shrinkage range with considerable similarity overlap. Inconsistent shrinkage behavior was evident and all materials reached maximum values before 24 h. No significant difference was observed during proposed digital same day all ceramic crown procedures, but some differences were noted at 24 h. CONCLUSIONS: Under this study's conditions results were material specific, at times inconsistent, with wide variation. Shrinkage consistently increased for all products and it is not known if the continued shrinkage magnitude may compromise the stability and fit of all-ceramic crowns at 24 h.

Resin Bonding of a Lithium-Disilicate Crown Using a Ligated Rubber Dam: A 2-Year Case Report.

Enduring glass-ceramic restorations greatly depend on the quality of adhesion of the crown to enamel and dentin. Proper isolation is vital to the success of bonded ceramic restorations. The rubber dam has long been considered the primary method of preventing contamination of the operating field, a crucial requisite for adhesion. However, many dentists do not use rubber dam isolation due to its penchant for slowing down procedures. The authors present a case report that describes a technique for the indirect bonding of a ceramic restoration to a maxillary first molar using rubber dam isolation in conjunction with a floss ligature,a method that is aimed at optimizing operator effectiveness and efficiency.

Miraculous Recovery After Penetrating Trauma to the Mediastinum.

Traumatic injury to the mediastinum can damage critical surrounding structures, including the pericardium, aorta, and bronchial tree. We highlight a miraculous case of a 13-year-old female with no past medical history who presented to the emergency department after being impaled in the chest by a metal fence post. After median sternotomy, the foreign object was removed, and the patient fortunately recovered with no permanent sequelae. The radiographic features of the injury are described, and potential unseen cardiovascular and respiratory complications are discussed.

"Learning from my experience": Acute abdomen - Perforated Meckel's diverticulitis.

This is a case report documenting the risk in imaging misinterpretation of a pediatric patient that presented with an acute abdomen. Computed Tomography (CT) demonstrated an inflamed blind ending loop of bowel in the pelvis without an obvious cecal connection. The patient was taken to the operative theater, a normal appendix and perforated Meckel's diverticulitis were resected. Meckel's diverticulum is the most common small bowel abnormality and can have complications. We will emphasize that imaging studies in a pediatric patient with Meckel's diverticulum are easily subject to errors radiologists make. This is such a cautionary and learning tale.

Minimally invasive esthetic improvement in a patient with dental fluorosis by using microabrasion and bleaching: A clinical report.

Dental fluorosis is a condition that produces unesthetic coloration of enamel because of excessive fluoride ingestion during enamel formation. Its appearance can range in severity from mildly white and opaque to dark brown and can lead a patient to seek dental treatment. Historically, these lesions have been masked, either with direct or indirect restorations, but more conservative treatment options are now available, including the combination of microabrasion and bleaching. This clinical report describes the use of these treatment options to address a young patient's dental fluorosis.

Correction of a Single Discolored Anterior Tooth Due to Internal Resorption: A Clinical Report.

For patients with a single discolored tooth who desire to have it lightened, a thorough examination and radiographic analysis need to be performed prior to initiating any bleaching treatment so that the cause of the discoloration can be determined. Underlying pathology, such as internal resorption, is often asymptomatic and difficult to diagnose and if left untreated could result in tooth loss. This article describes a case of a patient with a discolored maxillary central incisor resulting from internal resorption and the subsequent endodontic and bleaching therapy performed to resolve the pathology and achieve an acceptable esthetic result.

Caries Management with the International Caries Detection and Assessment System II: Established Pit and Fissure Lesions.

INTRODUCTION: Operative dentistry addresses the surgical management of caries, a significant portion of dental practice. Dental students, who typically develop their skill sets in this important discipline by creating idealized preparations in plastic teeth, are often confused by the wide variety of tooth anatomy and caries presentation they see when they subsequently treat patients. To address this significant clinical transition issue, we developed this resource on preparing the moderate carious lesion using a stepwise, structured technique. METHODS: This resource consists of a flipped-classroom learning module and associated laboratory activity with an algorithm worksheet to practice critical thinking skills. Prior to the exercise, an interactive tutorial introduces the didactic background. The 4-hour class session starts with a short quiz and review, then learners use the worksheet to prepare and restore their tooth specimens. RESULTS: Learner response has been very positive. Moreover, faculty note that learners' skills in treating patients in clinic are noticeably higher and require less faculty intervention than was previously the case. DISCUSSION: Since new national curriculum standards for caries are currently being introduced, in addition to providing instruction to dental students, this resource presents an excellent opportunity to calibrate faculty members, who are a secondary learner group in this exercise, on a standard clinical protocol.

Restoration of Anterior Dental Erosion with a Combination of Veneers and Crowns: A 3-Year Case Report.

This report describes the conservative management of a 40-year-old female patient with smooth, eroded facial enamel affecting her maxillary anterior and some posterior teeth. Using conventional enamel bonding, pressed leucite-reinforced laminate veneers were used to restore the length, contour, and esthetics of the maxillary right canine, as well as of the right lateral and both central incisors; at the same time, it was necessary to restore the maxillary left lateral incisor, canine, and first premolar of the same quadrant with all-ceramic crowns of the same material. The patient has been followed for 3 years and demonstrates a good esthetic outcome with no shade discrepancy between the two types of restoration. Apparently, the tooth structure, though eroded, was able to provide an adequate bonding substrate for these adhesive restorations.

Effect of Sodium Fluoride on the endogenous MMP Activity of Dentin Matrices.

OBJECTIVES: This study evaluated the effect of incorporating increasing concentrations of sodium fluoride in incubation media, on the loss of dry mass and solubilization of collagen from demineralized dentin beams incubated for up to 7 days. The effect of fluoride on the inhibition of matrix-bound metalloproteinases (MMPs) was also measured. METHODS: Dentin beams were completely demineralized in 10% phosphoric acid. After baseline measurements of dry mass, the beams were divided into six groups (n=10) and incubated at 37°C either in buffered media containing sodium fluoride (NaF) at 75, 150, 300, 450, 600 ppm or in fluoride-free media (control) for seven days. Following incubation, dry mass was re-measured. The incubation media was hydrolyzed with HCl for the quantitation of hydroxyproline (HYP) as an index of solubilization of collagen by endogenous dentin proteases. Increasing concentrations of fluoride were also evaluated for their ability to inhibit rhMMP-9. RESULTS: Addition of NaF to the incubation media produced a progressive significant reduction (p<0.05) in the loss of mass of dentin matrices, with all concentrations demonstrating significantly less mass loss than the control group. Significantly less HYP release from the dentin beams was found in the higher fluoride concentration groups, while fluoride concentrations of 75 and 150 ppm significantly reduced rhMMP-9 activity by 6.5% and 79.2%, respectively. CONCLUSIONS: The results of this study indicate that NaF inhibits matrix-bound MMPs and therefore may slow the degradation of dentin matrix by endogenous dentin MMPs.

Film thickness of crown disclosing material and its relevance to cementation.

STATEMENT OF PROBLEM: Regardless of the type of indirect restoration being fabricated, optimizing fit at cementation is a challenge. Several disclosing agents have been recommended to identify intaglio surface contacts that may result in incomplete seating and poorly adapted margins. The International Organization for Standardization has established a standard of 25 µm for the maximum film thickness for water-based cements. To accurately predict the clinical behavior of a luting cement, the disclosing agents themselves should have a film thickness no greater than 25 µm. PURPOSE: The purpose of this study was to determine the film thickness of 2 disclosing products, a spray-on powder (Occlude Indicator Marking Spray) and a silicone disclosing agent (Fit Checker). MATERIAL AND METHODS: The film thickness of the 2 disclosing products was determined by using optically flat glass cylinders according to the method set forth in International Organization for Standardization Standard 9917 for water-based cements. Because the silicone product is fast setting, the load was applied within 10 seconds of completing the mix. The spray-on product was allowed to dry before applying the load, in accordance with its intended clinical use. The film thickness of both products was determined with a load of 150 N applied for 30 seconds. Additional determinations were made for the silicone product at both 100 N and 50 N applied for 30 seconds and at 150 N applied for 90 seconds. An additional film thickness determination for the spray-on product was made with no load applied. The film thickness data for the various loads and intervals for the silicone product were analyzed with a 1-way ANOVA and the Tukey-Kramer multiple comparison test (α=.05). A t test (unequal variance, 2-tailed) was used to compare the spray-on and silicone products as measured at a load of 150 N applied for 30 seconds. RESULTS: The average film thickness of Fit Checker ranged from 16.7 to 23.7 µm, with the two 150-N groups significantly lower than the others, whereas that of Occlude was 67.7 µm unloaded and 48.4 µm when loaded. The film thickness of Fit Checker was significantly less than that of Occlude for the 150 N, 30-second group. CONCLUSION: Within the limitations of this study design, Fit Checker had a film thickness that satisfied the 25-µm limit imposed on water-based luting cements in the International Organization for Standardization standard, whereas Occlude Spray did not.

Four-year follow-up of the rehabilitation of a mandibular arch with a cementable zirconia-reinforced fixed dental prosthesis: a clinical report.

Implant-supported prostheses have been used extensively to rehabilitate completely edentulous arches. Although combinations of different restorative materials have reportedly been used to fabricate such prostheses, a metal framework is usually chosen for acrylic resin reinforcement. However, cost and the frequent need to section and solder to attain a passive framework fit are disadvantages for using metal. Zirconia has been used widely in restorative dentistry as an alternative to metal. This clinical report describes the fabrication of a zirconia-reinforced cementable fixed dental prosthesis with a 4-year follow-up.

Cytotoxicity of endodontic sealers after one year of aging in vitro.

The in vitro cytotoxic response to endodontic sealers was assessed for one year. AH-Plus (AHP), Epiphany (EPH), EndoRez (ER), Guttaflow (GF), InnoEndo (IN), and Pulp Canal Sealer (PCS) were exposed to mouse osteoblasts and human monocytes after curing, 52 weeks of aging, and after resurfacing post-aging; cellular response was estimated by succinate dehydrogenase (SDH) activity. The effect of materials on TNFα secretion from activated (LPS) and inactivated monocytes also was measured. Cell responses were compared with ANOVA and Tukey post hoc analysis (α = 0.05). Initially, all materials except GF suppressed osteoblastic SDH activity compared with Teflon (Tf) controls. SDH activity in cells exposed to some aged sealers improved significantly; but IN and ER remained cytotoxic. When aged materials were resurfaced then tested, AHP, ER, GF, and IN did not change. EPH and PCS were more toxic. Monocytes responded similarly to the osteoblasts. No endodontic sealer activated monocytic TNFα secretion (p > 0.05 vs. -LPS Tf-controls). LPS-activated monocytes exposed to unresurfaced AHP and IN significantly suppressed TNFα secretion. When activated monocytes were exposed to the resurfaced sealers, differential suppression of TNFα secretion was observed for three of the four sealers tested (EPH, IN, and PCS). The results suggest that long-term aging may be a useful adjunct to in vitro assessment of these materials.

New method of measuring water permeability of adhesive resin films.

PURPOSE: To adapt a simple gravimetric method to measuring the permeability of adhesive resin films to liquid water, and to compare this to the water vapor permeability of the same resins. METHODS: Using commercially-available permeability cups designed for industrial permeability testing, the loss of mass of water vapor or liquid water from a stainless steel cup sealed with a resin film was measured over 1-2 days. The permeabilities of Parafilm (control), Clearfil SE Bond adhesive, Xeno IV and One-Up Bond F were compared. RESULTS: The lowest resin film permeability was obtained with Clearfil SE Bond adhesive films. The permeabilities ofXeno IV and One-Up Bond F to liquid water were 2.76 and 3.27-fold higher (P < 0.001) than that of Clearfil SE Bond adhesive. Liquid water permeability was always 2.8-3.8-fold higher (P < 0.05) than water vapor transmission rate. It was concluded that quantitative comparisons of the permeability properties of resin films can be made gravimetrically. The large permeability cups that are available commercially may be reduced in size in the future for measuring dentin adhesive films with smaller surface areas that are less liable to contain imperfections.

Two-year clinical performance of Clearfil SE and Clearfil S3 in restoration of unabraded non-carious class V lesions.

This study was undertaken to evaluate the two-year clinical performance of a self-etching primer and a self-etching adhesive, both of which employ the same acidic monomer. Forty pairs of restorations of AP-X hybrid resin composite (Kuraray Co, Ltd, Osaka, Japan) were placed in caries-free cervical erosion/abfraction lesions. Based on insensitivity to air, the dentin in 62% of these lesions was considered to be sclerotic. The restorations were placed with no abrasion of tooth surfaces, except for cleaning with plain pumice and no use of phosphoric acid etching, which is counter to the manufacturer's instructions that call for etching of unprepared enamel. One restoration from each pair was placed using Clearfil SE Bond, an adhesive employing a self-etching primer, and the other was placed using Clearfil S3 Bond, a self-etching adhesive. To emulate the results likely to occur in a private practice, the restorations were placed by well-educated, experienced clinicians who had no particular expertise in adhesive dentistry research and who placed the restorations according only to their interpretation of the manufacturer's instructions. The restorations were clinically evaluated at baseline and at 6, 12 and 24 months, using modified Ryge/USPHS criteria. For both products, retention of 81%-84% of the restorations was observed over two years, which is lower than has been previously observed with these products and is likely due to limitations in the manufacturer's instructions compounded by inexperience of the operators in adhesive dentistry research. One restoration placed with each adhesive demonstrated secondary caries, which was probably attributable to the study being conducted in a non-fluoridated area and which reduced the percentages of clinically successful restorations to 78%-81%. No statistically significant difference (p = 0.50) between the two adhesives was observed in overall performance.

Color differences: polymerized composite and corresponding Vitapan Classical shade tab.

OBJECTIVES: This study compared newer composite resin restorative materials to the Vitapan Classical tabs they purported to represent. METHODS: Five Vitapan Classical tabs were studied: A3.5, B2, C1, C3, and D2 (n=3). These tabs created a variety of levels of lightness, chroma and hue. Each of these five shade tabs was removed from three different shade guides, and an intraoral spectrophotometer was used to capture CIELAB color coordinates. Three separate readings were made and all nine were averaged. The inter-tab color differences were also calculated. Five specimens approximately 4.0mm thick were fabricated for each of the shades studied using five different composite resin materials. Composite specimens were of the same size and shape as target shade tabs, and three separate recordings were made for each of them. This average was compared to five Vitapan Classical shade tabs to calculate the color differences using both CIELAB and CIEDE2000 color difference formulas. Color differences were compared to thresholds for perceptibility and acceptability reported in other studies. RESULTS: CIELAB and CIEDE2000 color differences ranged from 3.9 to 22.8 and from 2.1 to 13.8, respectively. None of the materials proved, an acceptable CIELAB color match to any of the shades tested. CONCLUSION: When various shade tabs of Vitapan Classical shade guides were compared with correspondent tabs made of direct restorative composites, no material/shade combination resulted in an acceptable mismatch relative to the used standard of acceptability. Therefore, evaluated resin composites exhibited poor match compared to target Vitapan Classical tabs.

Minimally retentive gold onlays: a six-year case report.

Partial veneer gold restorations, such as gold onlays, have changed little in preparation design over the past 40 years, as evidenced by textbooks that have long been in print. Such designs must have been based on the assumption that restorations would be luted with zinc phosphate cement but have not altered, despite the introduction of stronger luting cement classes, such as resin composite and resin-modified glass ionomer cements. It is well-established that both porcelain and base metal materials, which have been etched on the intaglio surface, can be combined with resin composite luting cements to produce restorations retained largely through adhesion. However, neither of these materials can equal the combination of minimal tooth reduction and margin adaptation that is possible with high noble gold restorative materials. Although high noble gold alloys cannot be etched, air abrasion of the intaglio surface of restorations likely improves micromechanical retention, but it is unknown whether this, along with a strong luting cement, is sufficient to stabilize high noble gold alloys in preparations with considerably less retention and resistance form than traditional designs.

Film thicknesses of recently introduced luting cements.

STATEMENT OF PROBLEM: A luting cement must maintain a minimum film thickness over a sufficient period of time to allow seating of indirect restorations. The performance of newer luting cements in this regard has not been evaluated. PURPOSE: The purpose of this study was to compare the film thicknesses of 6 luting cements, 2 resin-modified glass ionomer (FujiCEM and RelyX Luting Plus), 2 composite resin (Panavia 21 and RelyX ARC), and 2 self-adhesive resin (Maxcem and RelyX Unicem) cements, over 3 minutes. MATERIAL AND METHODS: The film thickness (microm) of each cement (n=7) was determined at room temperature at 1, 2, and 3 minutes after the start of mixing, according to the testing method set forth in ISO Standard 9917. Means of all cements were compared at the 2-minute interval, and means at the 1- and 3-minute intervals for each were compared to the mean for the same cement at 2 minutes, using 1-way analyses of variance (ANOVA) and Tukey-Kramer multiple comparison tests (alpha=.05). RESULTS: Except for 1 resin-modified material at 3 minutes, a point beyond its specified working time, all materials produced film thicknesses under 30 microm at 3 minutes and under 26 microm at 2 minutes. CONCLUSIONS: All of the materials tested meet the ISO standard of 25-microm maximum film thickness for up to 2 minutes after mixing.