Evaluation of mechanical, optical, and fluoride-releasing properties of a translucent bulk fill glass hybrid restorative dental material.

OBJECTIVE: Measure and compare the mechanical properties, translucency, and fluoride-releasing capabilities of EQUIA Forte HT against Fuji IX GP and ChemFil Rock. MATERIALS AND METHODS: Ten specimens of each material were fabricated for compressive strength (CS), flexural strength (FS), and surface hardness analysis at 24 h and 7 days. The L*a*b* values were measured against a black-and-white background using a spectrophotometer to analyze the translucency parameter (TP). Fluoride release was recorded after 2 months of immersion in distilled water. The mean data was analyzed by 1- and 2-way ANOVA (α = 0.5). RESULTS: EQUIA Forte HT showed higher CS, surface hardness, and FS values (p < 0.05) compared with Fuji IX GIC, while no significant difference was found in FS values between EQUIA Forte HT and Chemfil Rock (p > 0.05). The EQUIA Forte HT exhibited significantly higher translucency in comparison to both ChemFil Rock (p < 0.001) and Fuji IX GICs (p < 0.05). An increase (p > 0.05) of fluoride release was observed for EQUIA Forte HT. CONCLUSION: The EQUIA Forte HT Glass-ionomer cements (GIC) offers enhanced translucency, improved strength, and enhanced fluoride-releasing properties compared to the traditionally used Fuji IX GIC and ChemFil Rock GICs. This material might have a wide range of clinical applications due to its improved strength and optical properties. CLINICAL SIGNIFICANCE: Glass-ionomer dental restorative materials possess unique advantageous characteristics. However, its poor mechanical and optical properties have typically limited its clinical applications. Efforts to improve these properties have resulted in enhanced GICs. EQUIA Forte HT GIC offers enhanced mechanical and optical properties with potential applications in posterior and anterior restorative procedures.

In vitro analysis of monomer leaching in modern dental materials: CAD milled, printed, traditional heat-processed, and auto-polymerizing denture base resins.

PURPOSE: Denture fabrication has shifted from traditional heat-processed and auto-polymerizing materials to computer-aided design and computer-aided manufacturing (CAD-CAM) milled and printed materials. The monomer in traditional materials can induce an allergic reaction in some patients. With the rise in the edentulous population and increasing demand for the fabrication of dentures, these newer materials should be studied for monomer leaching. The purpose of this study was to evaluate the ratio of residual monomer in materials being used for denture bases: CAD-milled polymethylmethacrylate (PMMA), printed denture base resin, heat-processed PMMA, and auto-polymerizing PMMA comparatively. MATERIALS AND METHODS: Milled, printed, heat-activated, and auto-polymerizing denture base specimens (n = 3 for each group, each test run three times) were fabricated according to manufacturer recommendations. Specimens were first immersed in deuterated chloroform (CDCl3), a deuterated organic solvent, to evaluate monomer leaching and to observe physical properties of the materials. NMR spectroscopy was used to evaluate the dissolution of materials and residual monomer to crosslinked polymer ratios at 1, 4, and 9 days. A second group of specimens was then immersed in deuterium oxide (D2O) to evaluate if the residual monomers would leach out of the system. The solution was then analyzed using nuclear magnetic resonance (NMR) spectroscopy for 1 month. The deuterated forms of chloroform (CDCl3) and water (D2O) were used to enable sample characterization by NMR. RESULTS: While the heat-processed, auto-polymerizing, and milled specimens possessed residual monomers, no significant monomer leaching was noted in the printed specimen, while immersed in CDCl3. Similarly, the printed specimen was most resistant to dissolution, as compared to the rest; dissolution of the specimen is indicative of little to no cross-linking. No detectable dissolution of monomer was seen when all specimens were immersed in D2O for up to 1 month. CONCLUSIONS: Residual monomers were not found in the printed denture material in this study in either CDCl3 or D2O, whereas CAD-milled and traditionally processed denture bases still have residual monomers within their respective systems when immersed in organic solvent. None of the specimens tested leached monomers into D2O.

In Vitro Analysis of Shear Stress: CAD Milled vs Printed Denture Base Resins with Bonded Denture Tooth.

PURPOSE: As the fabrication of computer-aided design (CAD) milled and 3D printed denture base resins with bonded denture teeth increase in popularity, there is a need for research comparing the shear bond stress of milled and printed denture base resins with bonded denture teeth to that of a conventional heat processed denture base. MATERIALS AND METHODS: Denture base resin specimens (n = 9) were fabricated according to manufacturers' instructions using a novel test design. Two milled (Ivobase CAD PMMA, Ivoclar Vivadent and Polident PMMA, Polident Dental) and two 3D printed (Denture Base LP Resin, Formlabs and Lucitone Digital Print, Dentsply Sirona) materials were used. Conventional heat processed polymethylmethacrylate was used as the control (Lucitone 199, Dentsply Sirona). Denture teeth (VITA Vitapan XL T44, #8, VITA Zahnfabrik) were bonded to their respective bases using denture tooth bonding agent (Ivobase CAD bonding system, Ivoclar). Specimens were aged in water for 600 hours at 37°C and loaded until failure in a Universal testing machine. Shear bond stress was calculated. All specimens were evaluated for mode of failure and select specimens under scanning electron microscope and vertical scanning interferometry. Data were analyzed with one-way ANOVA followed by Tukey test (IBM SPSS) and fracture analysis performed. RESULTS: Shear stress was highest for the heat processed control (mean = 180 N ±26.76) and Polident test groups (mean = 180 N ± 34.90). Milled specimens were not significantly different from the control (p = 0.076 for IvoBase CAD and 1.00 for Polident), while the printed groups were significantly different from the control (p = 0.012 for Formlabs Denture Base Resin and p = 0.00 for Carbon Lucitone Digital Print). Milled denture base resins performed similarly to heat processed denture base resin and better than 3D printed denture bases. CONCLUSION: For complete denture wearers, all resin materials used in this study may be clinically acceptable, as the sheer stress for all groups was higher than the reported maximum biting force of complete denture patients. However, for implant retained prostheses, the incorporation of additional retentive features should be considered when bonding denture teeth to printed bases. More research is needed to evaluate methods to increase the bond strength of denture teeth to printed denture base resins.

A dual scan approach to creating an accurate dental surface for virtual implant planning: A dental technique.

Artifacts from metal restorations can make it challenging or impossible to accurately orient a digital dental cast to cone beam computed tomography (CBCT) scan data for virtual implant planning. A dual scan technique is described that uses an alginate impression with fiducial markers in a stock tray to create a digital dental cast that is precisely oriented to the scan in the same patient coordinate system for surgical guide design.

Bond strength of three chairside crown reline materials to milled polymethyl methacrylate resin.

STATEMENT OF PROBLEM: Information on the bond strength of milled polymethyl methacrylate interim restorations when relined with chairside reline materials is lacking. PURPOSE: The purpose of this in vitro study was to measure the shear bond strength of various combinations of 3 different chairside reline materials bonded to milled polymethyl methacrylate blocks with 3 different types of surface treatments. MATERIALS AND METHODS: Uniform blocks (10×10×22 mm) were milled from tooth-colored polymethyl methacrylate disks (Vivid PMMA; Pearson Dental Supply Co). The surface treatments tested were airborne-particle abrasion with 50-µm particle size aluminosilicate, application of acrylic resin monomer (Jet Liquid; Lang Dental Manufacturing Co) for 180 seconds, and airborne-particle abrasion with monomer application. The control groups were blocks with no surface treatment. The chairside reline materials tested were Jet acrylic resin (Jet Powder; Lang Dental Manufacturing Co), bis-acryl resin (Integrity; Dentsply Sirona), and flowable composite resin (Reveal; Bisco). All materials were applied through a Ø1.5×3-mm bonding ring. Ten specimens for each of the 12 groups were tested in a universal testing machine. Load was applied at a crosshead speed of 1 mm/min. Fracture surfaces were then analyzed for cohesive versus adhesive or mixed failure. Data were analyzed using 2-way ANOVA and Tukey-Kramer post hoc analysis (α=.05). RESULTS: The mean shear bond strength values ranged from 1.77 ±0.79 MPa to 28.49 ±5.75 MPa. ANOVA revealed that reline material (P<.05), surface treatment (P<.05), and their interactions (P<.05) significantly affected the shear bond strength among the experimental groups. The strongest combination was Jet acrylic resin applied on specimens treated with airborne-particle abrasion and monomer. All 3 failure modalities (adhesive, cohesive, and mixed modes) were observed. CONCLUSIONS: Of the materials tested, the most reliable material to bond to milled polymethyl methacrylate was Jet acrylic resin, and the bond strength values were increased substantially when the milled polymethyl methacrylate surface was airborne-particle abraded and monomer was applied.

Transferring dentofacial analyzer into analog workflow with CAD digitization: A dental technique.

With the transition to digital workflows, moving from a digital platform to an articulator for laboratory procedures such as adding porcelain or luting titanium abutments is sometimes required. This report describes a technique to facilitate the transfer of jaw-relation records to a digital mounting template. Once digitally mounted, the casts can be printed with mounting plates attached to the temporomandibular joints in the appropriate orientation. They can then be placed in an articulator and used for layering porcelain or luting titanium abutments for screw-retained restorations.

Evaluation of a shape memory implant abutment system: An up to 6-month pilot clinical study.

STATEMENT OF PROBLEM: Screw- and cement-based retention mechanisms are used to attach prostheses to dental implants; however, each approach can lead to clinical complications such as crown fracturing or peri-implantitis. A novel abutment and prosthesis retention system has been engineered to achieve the esthetics and retention force of cement-based fixation while maintaining the retrievability of screw-retained restorations. PURPOSE: The purpose of this pilot clinical study was to evaluate the effectiveness of this innovative retention system on posterior tooth restorations. MATERIAL AND METHODS: This clinical study, with up to 6 months of follow-up, included 8 participants with posterior osseointegrated implants who met the eligibility criteria to receive the abutment and shape memory sleeve. Radiographs were used to evaluate crown seating. Crown stability was measured using the Periotest, and occlusal analysis was performed using the Tekscan system and shimstock. Peri-implant health was evaluated by probing, and the plaque and gingival indices were recorded. In addition, patient-reported outcomes were recorded. RESULTS: Minimal differences were observed between baseline and endpoint assessment of the plaque and gingival indices, probing depth, and proximal and occlusal contacts. There were no patient-reported problems or complaints about discomfort. The overall peri-implant health remained unchanged from the baseline evaluations for all participants. Proximal contact around the restoration was present at the baseline and at the conclusion of the study for 7 of the participants. Occlusal contact was observed to be either light (5 participants) or holding (3 participants). In addition, visual inspection of retrieved crowns revealed clean surfaces free of macroparticle ingress, and bacterial accumulation at the coping-abutment interface was not detected. CONCLUSIONS: The safety and efficacy findings of this pilot clinical study suggest that this new shape memory alloy-based retention system may provide a suitable alternative for implant prosthodontics. The retention system allowed for easy prosthesis seating and retrieval.

Digital workflow for predictable immediate loading in the mandible by using a shape memory dental implant abutment system: A clinical report.

Digital surgical planning for immediately loaded dental implants can be a predictable and accurate procedure, with the interim prosthesis also designed digitally. If the planning and execution are meticulous, chairside adjustments can be minimized because the outcome should be closely matched to the proposed digital plan. A novel dental implant abutment system made from a shape memory metal could be an answer to the cement versus screw controversy as it uses neither. This new system can provide patients with better esthetics and is biologically favorable.

Evaluation of the wear and retention performance of a shape-memory alloy abutment system after 6 months of clinical use.

STATEMENT OF PROBLEM: A nitinol sleeve that uses shape memory to rapidly unlock dental restorations from implant abutments has been developed to allow prosthesis removal for assessment and maintenance, and clinical treatment has been promising. However, objective studies that evaluate the wear and retention performance after short-term clinical use are lacking. PURPOSE: The purpose of this clinical study was to evaluate the wear and retention performance of a shape-memory abutment system after 6 months of clinical use. MATERIAL AND METHODS: Shape-memory alloy sleeves on posterior osseointegrated implants were retrieved after 6 months of clinical use. Scanning electron microscopy (SEM) was used to evaluate the surfaces of the retention sleeve's arms for wear. Uniaxial tensile testing was performed to measure the change in retention force after clinical use. Average retention values of the shape-memory abutment system were compared with previously reported in vitro retention values for definitive and interim cements used in titanium abutment and coping assemblies by using the Welch t test. RESULTS: No evidence of wear, fracture, or chipping was observed during SEM analysis on the shape-memory alloy sleeves. Additionally, no statistically significant difference was found in the median retention force for new (484.5 N) and clinically retrieved (476 N) nitinol sleeve specimens. Compared with a commercially available resin cement, the mean retention force for the control sleeves (480 ±37 N) was higher than that for the freshly cemented specimens (336.3 ±188 N). After 5000 cycles of compressive loads, the mean retention force for cement specimens decreased (209.4 ±83 N), while the clinical sleeves (476 ±50 N) remained unchanged. CONCLUSIONS: According to the results of this study, after 6 months of clinical use, the engaging surfaces of the shape-memory alloy sleeve did not show signs of wear, and the retention force was unchanged.

Digital custom implant impression technique for capturing the acquired emergence profile.

A digital method for capturing the acquired emergence profile from contoured implant interim restorations is described. Three separate digital scans were made by using an intraoral scanner and aligned by using a design software program capable of merging and alignment. The Boolean Difference function was then performed by using a free software program to obtain the emergence profile. This technique may be less time-consuming than analog methods and may be more accurate than existing digital methods.

Comparative evaluation of the physical properties of a reinforced glass ionomer dental restorative material.

STATEMENT OF PROBLEM: While glass ionomer cements have many unique properties and advantages, they still lack favorable mechanical properties. EQUIA Forte Fil is a newly developed glass ionomer cement (GIC) with improved mechanical strength. However, research and data on the physical properties of EQUIA Forte Fil are lacking. PURPOSE: The purpose of this in vitro study was to evaluate and compare the compressive, diametral tensile, and flexural strengths of EQUIA Forte Fil with Fuji IX GP and ChemFil Rock, restorative GICs commonly used in dentistry. Moreover, fluoride-releasing properties and surface hardness of the GICs were also assessed. MATERIAL AND METHODS: Ten disk-shaped specimens of each GIC (EQUIA Forte Fil, Fuji IX GP, and ChemFil Rock) were fabricated for mechanical and surface hardness tests by using polydimethylsiloxane (PDMS) molds. The specimens were tested after 24 hours and 7 days of immersion in distilled water at 37 °C. By using a mechanical testing machine, the compressive, diametral tensile, and flexural strengths of each GIC were measured. Fluoride-releasing properties were also evaluated (10 specimens per group). A microhardness tester was used to measure the surface hardness. The mean data were analyzed by using 1- and 2-way ANOVA (α=.05). RESULTS: EQUIA Forte Fil glass ionomer cements exhibited significantly greater (P<.05) flexural strength and surface hardness than Fuji IX GIC specimens. However, no significant difference (P>.05) was observed between the compressive and diametral tensile strength of EQUIA Forte Fil and Fuji IX GIC specimens. ChemFil Rock exhibited higher flexural strength than EQUIA Forte Fil (P>.05) but significantly lower compressive strength and microhardness (P<.05). Tested GICs matured after 1 week of immersion in distilled water, demonstrating a significant improvement in their mechanical properties. All the examined glass ionomers exhibited comparable initial fluoride-releasing properties, whereas EQUIA Forte Fil exhibited significantly higher (P<.05) amounts of fluoride release from the bulk of the material after 4 weeks. CONCLUSIONS: EQUIA Forte Fil is a promising restorative material with superior flexural strength and surface hardness compared with its predecessor, Fuji IX GP, or other commercially available glass ionomers.

Effects of an etching solution on the adhesive properties and surface microhardness of zirconia dental ceramics.

STATEMENT OF PROBLEM: Conventional approaches to adhesive bonding are not applicable to zirconia restorations. Recently, an etching solution, Zeta Etching Solution (ZES), has been introduced for etching the surface of zirconia. The effects of this etching solution on the bond strength and mechanical properties of zirconia are unknown. PURPOSE: The purpose of this in vitro study was to examine the effects of ZES on the bond strength and surface hardness of zirconia. MATERIAL AND METHODS: Two different types of partially stabilized tetragonal polycrystalline zirconia (TZP), Prettau zirconia (group P) and anterior Prettau (group AP), were evaluated with and without ZES etching. Each group was bonded to a zirconia substrate by using an adhesive resin cement. After 24 hours of storage in distilled water, the bond strength of the zirconia was analyzed. Vickers hardness was determined by using a microhardness tester. Scanning electron microscopy was used to analyze the surface microstructure and determine the mode of failure for each specimen. Results were analyzed and compared using 1-way ANOVA and Student t tests (α=.05). RESULTS: Scanning electron microscopy analysis showed that etching the surface of zirconia with ZES etching solution for 60 minutes changed the morphological characteristics and microstructure of zirconia, making the surface more irregular. The changes were more pronounced for AP specimens. Etching with ZES significantly increased the shear bond strength of zirconia (P<.05) in AP specimens. The bond strength of Prettau (P group) specimens after ZES etching did not increase significantly (P>.05). An adhesive failure mode was observed for P zirconia specimens, whereas zirconia specimens exhibited a cohesive mode of failure. No significant decrease (P>.05) was observed in the mean Vickers hardness numbers. CONCLUSIONS: Within the limitations of this in vitro study, it was concluded that etching in ZES for 30 minutes significantly enhanced the shear bond strength of highly translucent anterior Prettau (AP) zirconia restorations. Moreover, etching with ZES did not adversely affect the surface hardness of the zirconia specimens tested.

Clinical application of a shape memory implant abutment system.

An innovative abutment system has recently been developed to address the well-known limitations of screw- and cement-retained implant restorations. This abutment system offers retrievability by replacing the cement layer with a precision-engineered nickel-titanium sleeve that switches between shapes that lock and unlock the prosthesis. The avoidance of cement precludes cement-related periimplant complications, while the elimination of occlusal screw access holes may enable predictable control over occlusion and improve the structural integrity of the prosthesis. By eliminating the need for cement clean up, occlusal access closure, and occlusal adjustments after insertion, the dentist is afforded more time to attend to the patient's general needs. This paper describes the design rationale for and clinical treatment using this novel abutment system.

Dental and orofacial mesenchymal stem cells in craniofacial regeneration: The prosthodontist's point of view.

Of the available regenerative treatment options, craniofacial tissue regeneration using mesenchymal stem cells (MSCs) shows promise. The ability of stem cells to produce multiple specialized cell types along with their extensive distribution in many adult tissues have made them an attractive target for applications in tissue engineering. MSCs reside in a wide spectrum of postnatal tissue types and have been successfully isolated from orofacial tissues. These dental- or orofacial-derived MSCs possess self-renewal and multilineage differentiation capacities. The craniofacial system is composed of complex hard and soft tissues derived from sophisticated processes starting with embryonic development. Because of the complexity of the craniofacial tissues, the application of stem cells presents challenges in terms of the size, shape, and form of the engineered structures, the specialized final developed cells, and the modulation of timely blood supply while limiting inflammatory and immunological responses. The cell delivery vehicle has an important role in the in vivo performance of stem cells and could dictate the success of the regenerative therapy. Among the available hydrogel biomaterials for cell encapsulation, alginate-based hydrogels have shown promising results in biomedical applications. Alginate scaffolds encapsulating MSCs can provide a suitable microenvironment for cell viability and differentiation for tissue regeneration applications. This review aims to summarize current applications of dental-derived stem cell therapy and highlight the use of alginate-based hydrogels for applications in craniofacial tissue engineering.

Dermal Filler Presenting as Lobular Radiopacities in an Edentulous Patient: A Clinical Report.

This clinical report describes the unusual appearance of radiopacities, lobular in nature, observed on a dental panoramic image of an edentulous patient. Upon questioning, the patient described a history of recently having hydroxylapatite-based dermal filler placed in her right and left cheeks to reduce wrinkles and enhance cosmetic appearance. The localization and shape of the radiopacities were consistent with the placement of the dermal filler.

Factors Influencing Resident Choice of Prosthodontic Residency Program.

PURPOSE: The decision by prosthodontic residency program directors to employ the Match process highlights the need to understand applicant priorities that influence their choice of which programs to rank highly. The purpose of this study is to determine the factors that were most important to residents when choosing from among nonmilitary based prosthodontics dental residency programs in the United States. MATERIALS AND METHODS: Following completion of a pilot study, all currently enrolled prosthodontic residents at nonmilitary residency programs were invited to participate via the internet. The study consisted of a survey instrument asking residents to rank 26 possible factors that might impact an applicant's choice of residency program. In addition, the instrument collected other possible influencing variables including gender and debt load. Mean rank scores were compared to determine the most and least important factors. Kruskal-Wallis test was used to compare specific factors between the possible influencing variables. RESULTS: Two hundred and thirty residents completed the survey instrument, representing a 54.1% response rate of possible participants. With regard to factors influencing program choice, reputation of the residency program was the factor ranked the highest by participants, followed in descending order by the program director's personality, curriculum content, access to use of the latest digital technology, and opportunities for dental implant placement. Quality of schools for children, community outreach opportunities, and the ability to moonlight were ranked as the least important factors. Male and female residents ranked factors such as tuition/stipend, curriculum content, and community outreach opportunities significantly differently. Depending on debt load, residents ranked the factors tuition/stipend, ability to moonlight, curriculum content, and safety of the area where the program is differently. CONCLUSIONS: Current prosthodontic residents valued the reputation of the program as the most important factor when applying to residency. Participant gender and debt load influence the factors chosen by residents as more or less important. These data will assist prosthodontic educators position their programs in the best possible light to attract applicants to their programs.

A Retrospective, Multicenter, Cross-Sectional Case Series Study Evaluating Outcomes of CAD/CAM Abutments on Implants from Four Manufacturers: 4-Year Mean Follow-up.

PURPOSE: To evaluate the clinical, radiographic, and prosthetic outcomes of a single custom CAD/CAM abutment system on implants from four manufacturers, with a mean clinical service of 4 years in a retrospective, multicenter case series study. MATERIALS AND METHODS: Adult subjects (n = 142) previously restored with titanium or gold-shaded titanium nitride custom CAD/CAM abutments (Atlantis, Dentsply Sirona; n = 259) connected to implants from four different manufacturers (Dentsply Sirona Implants [AT], Biomet 3i [BM], Nobel Biocare [NB], Straumann [ST]), irrespective of implant-abutment interface, and replacing one or more teeth in any position were recalled for a single-visit examination by calibrated investigators at six university clinics. The primary outcomes evaluated included abutment success and survival; secondary outcomes included assessment of papillae fill, probing pocket depth (PD), bleeding on probing (BOP), marginal bone levels (MBLs), and patient-reported outcome measures (PROMs). RESULTS: Two-hundred fifty-five (98.5%) abutments supported cement-retained restorations, and four (1.5%) abutments supported screw-retained restorations. Forty-two patients had 64 AT implants (25%), 31 patients had 61 BM implants (24%), 26 patients had 50 NB implants (19%), and 43 patients had 84 ST implants (32%). The overall implant-CAD/CAM abutment success rate was 92.66% (95% CI: 88.78%, 95.53%) for all implants examined, and the survival rate was 98.84% (95% CI: 96.65%, 99.76%) for all implants evaluated. The Jemt papillae index demonstrated a minimum of at least 50% to complete fill of the interproximal papillae in 65.0% of sites. PDs had a median value of 3.0 mm, and BOP was present on 19% of abutment surfaces. Mean MBL changes from the time of placement to exam were -0.24 ± 0.99 mm (-4.9 to 2.3; P = .058) for mesial sites and -0.32 ± 0.96 mm (-4.9 to 2.1; P = .000) for distal sites. PROMs expressed 93% of patients reporting good to very good masticatory function, 97% of patients reporting being satisfied or very satisfied with their esthetic outcomes, and 94% of patients indicating that they were satisfied or very satisfied with their overall implant-restorative outcomes. CONCLUSION: This retrospective, multicenter clinical study of FDA 510k-approved titanium CAD/CAM abutments of a single manufacturer on multiple implant systems demonstrated high levels of success and survival as well as stable peri-implant tissue outcomes, reflected by overwhelmingly positive PROMs.

The impact of a cardiopulmonary resuscitation video on reducing surrogates' anxiety: A pilot randomized controlled trial.

PURPOSE: To test the primary hypothesis that a CPR video will reduce ICU patients' surrogates' anxiety when deciding code status, as measured by the Hamilton Anxiety Rating (HAM-A) Scale, as compared to the no video group. MATERIALS AND METHODS: This is a prospective randomized control trial. Twenty-seven ICU patients' surrogates were enrolled in the study after receiving an ICU team-led code status discussion. After the enrollment, twelve surrogates were randomized to the video group and fifteen to the no video group. The primary outcome of anxiety was quantified using the HAM-A Scale. Demographic information, clinical data, and patients' provenance information (Home vs. Not Home) were collected. The patients' severity of illness was calculated using the Sequential Organ Failure Assessment (SOFA) Score. RESULTS: The HAM-A score in the video group was 5.65 points lower than in the no video group ([ß = -5.65, 95% CI -11.12 -0.18] P = 0.04). The statistically significant difference was maintained when adjusting for patients' SOFA Score and patients' provenance (P = 0.03). CONCLUSION: CPR video used to supplement ICU team-led code status discussions reduced surrogates' anxiety, as compared to no video. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03630965.

A review of the analysis of tobacco-specific nitrosamines in biological matrices.

Tobacco use constitutes a leading cause of mortality and morbidity worldwide. Tobacco-specific nitrosamines (TSNAs) are an important class of biomarkers for tobacco carcinogen uptake. The current review focuses on the issues and developments in analysis of these compounds in human biological matrices. The two most widely used techniques for TSNA bioanalysis are gas chromatography coupled with thermal energy analysis and liquid chromatography coupled with mass spectrometry, employing various sample preparation techniques. The review provides an overview of the tools and techniques currently available for TSNA bioanalysis that will help towards the ultimate goal of understanding the mechanisms of cancer caused by the use of tobacco products. A contrast and comparison of the important aspects of bioanalysis such as sample preparation, compound detection, and throughput is discussed for the thermal energy analysis- and mass spectrometry-based techniques. Complex sample extraction procedures, throughput, and the ability to validate are important issues of concern for the gas chromatography-thermal energy analysis-based methods. On the other hand, addressing ion suppression matrix effects remains an important challenge for hyphenated mass spectrometry-based methods. The review also provides an extensive summary of analytical procedures for various studies measuring tobacco-specific nitrosamines in different biological matrices.