Chemical characterization of polymer and chloride content in waste plastic materials using pyrolysis - direct analysis in real time - high-resolution mass spectrometry.

The increasing global demand for plastic has raised the need for effective waste plastic management due to its long lifetime and resistance to environmental degradation. There is a need for rapid plastic identification to improve the mechanical waste plastic sorting process. This study presents a novel application of Temperature-Programmed Desorption-Direct Analysis in Real Time-High Resolution Mass Spectrometry (TPD-DART-HRMS) that enables rapid characterization of various plastics.

Trueness and precision of complete arch dentate digital models produced by intraoral and desktop scanners: An ex-vivo study.

Objectives: The study aimed to compare the trueness and precision of five intraoral scanners (Emerald S, iTero Element 5D, Medit i700, Primescan, and Trios 4) and two indirect digitization techniques for both teeth and soft tissues on fresh mandibular and maxillary cadaver jaws.

Methods: The maxilla and mandible of a fully dentate cadaver were scanned by the ATOS industrial scanner to create a master model. Then, the specimens were scanned eight times by each intraoral scanner (IOS).

Assessing the Antimicrobial Properties of Copper-Iodide Doped Adhesives in an Caries Model: A Pilot Study.

Context: Recurrent caries are the leading cause of composite resin failure.

Aims: The purpose of this pilot study was to test the efficacy of a novel copper iodide (CuI) containing dental adhesive in an caries model.

Subjects And Methods: and were grown individually on the complex medium for 48 h at 37°C.

Evaluation of the accuracy of multiple digital impression systems on a fully edentulous maxilla.

Objective: This study aimed to compare the accuracy performance of five different intraoral scanning systems for a full-arch scan on an edentulous cadaver maxilla.

Method And Materials: Five digital intraoral impression systems were used to scan a fully edentulous cadaver maxilla. A master scan obtained with an ATOS Capsule industrial grade scanner provided the point of comparison.

Evaluation of complete-arch implant scanning with 5 different intraoral scanners in terms of trueness and operator experience.

Statement Of Problem: The intraoral scanning of the edentulous arch might be challenging for an inexperienced operator because of the large mucosal area and the use of scan bodies.

Purpose: The purpose of this ex vivo study was to compare the trueness of 5 intraoral scanners in replicating implant scan bodies and soft tissues in an edentulous maxilla and to investigate the effects of operator experience.

Material And Methods: The maxilla was resected from a fresh cadaver, 5 implants placed, and a reference scan made.

The effect of software updates on the trueness and precision of intraoral scanners.

Objectives: The goal of the study was to determine the effects of software updates on the trueness and precision of digital impressions obtained with a variety of intraoral scanner (IOS) systems.

Method And Materials: Seven IOS systems were investigated. Each system was tested using two versions of software, with the second version being the latest at the time of conducting the study.

Comparing the trueness of seven intraoral scanners and a physical impression on dentate human maxilla by a novel method.

Backgrounds: Intraoral scanner (IOS) accuracy is commonly evaluated using full-arch surface comparison, which fails to take into consideration the starting position of the scanning (scan origin). Previously a novel method was developed, which takes into account the scan origin and calculates the deviation of predefined identical points between references and test models. This method may reveal the error caused by stitching individual images during intraoral scan.

The effect different substrates have on the trueness and precision of eight different intraoral scanners.

Objective: This in vitro study compares the newest generation of intraoral scanners to their older counterparts, and tests whether material substrates affect the trueness and precision of intraoral scanners (IOS).

Material And Methods: A custom model, used as the reference standard, was fabricated with teeth composed of different dental materials. The reference standard scan was obtained using a three-dimensional (3D) optical scanner, the ATOS III.

A novel method for complex three-dimensional evaluation of intraoral scanner accuracy.

Aims: The aim of this study was to compare two existing methods and one novel method for measuring the distortion of three-dimensional (3D) models created with complete-arch digital impressions, and to assess the accuracy of different scan patterns using these methods.

Materials And Methods: Maxillary and mandibular models were imaged with the PlanScan intraoral scanner using four different scan patterns. Accuracy and distortion were assessed by comparing the master scans with the intraoral scans using the following three methods: 1) Mean surface deviation was measured after complete arch superimposition; 2) 28 points were selected identically on the experimental and on the master reference models, and the deviation between identical points was assessed after superimposition over the complete arch; 3) In the case of the novel technique, the superimposition was made only at the scanning origin, and after that the 28 points were compared.

Elucidating the Geometric Substitution of Petroporphyrins by Spectroscopic Analysis and Atomic Force Microscopy Molecular Imaging.

Determination of the molecular structures of petroporphyrins has been crucial to understand the diagenetic pathways and maturation of petroleum. However, these studies have been hampered by their structural complexity and the challenges associated with their isolation. In comparison to the skeletal macrocyclic structures, much less is known about the substitutions, which are more sensitive to the maturation and diagenesis pathways.

Effect of scan substrates on accuracy of 7 intraoral digital impression systems using human maxilla model.

Objective: This study aimed to determine how the accuracy of digital impressions was affected by four common dental substrates using seven prevalent IOS systems to scan the complete arch of a human maxilla.

Setting And Sample Population: The Department of Oral Rehabilitation at the Medical University of South Carolina. A single cadaver maxilla.

Evaluation of the trueness and precision of complete arch digital impressions on a human maxilla using seven different intraoral digital impression systems and a laboratory scanner.

Objectives: An impression accuracy study using a cadaver maxilla was performed using both prepared and intact teeth as well as palatal tissue.

Materials And Methods: Three crown preparations were performed on a cadaver maxilla. Seven different digital impression systems along with polyvinylsiloxane impressions were used to create digital models of the maxilla.

Effect of scan pattern on complete-arch scans with 4 digital scanners.

Statement Of Problem: Complete-arch digital scans are becoming popular as digital dentistry is adopted for expanded clinical situations such as complete-arch prostheses, removable prostheses, extensive implant-supported treatment, and orthodontic aligners. Whether the scan pattern technique affects the trueness and precision of complete-arch scans and whether differences in accuracy exist among different scanners remain unclear. Furthermore, each manufacturer recommends a different scan pattern, but evidence of the superiority of the manufacturer's recommended pattern is lacking.

Evaluation of the effect scan pattern has on the trueness and precision of six intraoral digital impression systems.

Objective: Clinicians have been slow to adopt digital impression technologies due possibly to perceived technique sensitivities involved in data acquisition. This research has two aims: determine whether scan pattern and sequence affects the accuracy of the three-dimensional (3D) model created from this digital impression and to compare the 5 imaging systems with regards to their scanning accuracy for sextant impressions.

Materials And Methods: Six digital intraoral impression systems were used to scan a typodont sextant with optical properties similar to natural teeth.

Anatomic Customization of Root-Analog Dental Implants With Cone-Beam CT and CAD/CAM Fabrication: A Cadaver-Based Pilot Evaluation.

Existing root-analog dental implant systems have no standardized protocols regarding retentive design, surface manipulation, or prosthetic attachment design relative to the site's unique anatomy. Historically, existing systems made those design choices arbitrarily. For this report, strategies were developed that deliberately reference the adjacent anatomy, implant and restorable path of draw, and bone density for implant and retentive design.

A novel technique for reference point generation to aid in intraoral scan alignment.

Objective: When using a completely digital workflow on larger prosthetic cases it is often difficult to communicate to the laboratory or chairside Computer Aided Design and Computer Aided Manufacturing system the provisional prosthetic information. The problem arises when common hard tissue data points are limited or non-existent such as in complete arch cases in which the 3D model of the complete arch provisional restorations must be aligned perfectly with the 3D model of the complete arch preparations. In these instances, soft tissue is not enough to ensure an accurate automatic or manual alignment due to a lack of well-defined reference points.

Evaluation of the accuracy of 7 digital scanners: An in vitro analysis based on 3-dimensional comparisons.

Statement Of Problem: As digital impressions become more common and more digital impression systems are released onto the market, it is essential to systematically and objectively evaluate their accuracy.

Purpose: The purpose of this in vitro study was to evaluate and compare the trueness and precision of 6 intraoral scanners and 1 laboratory scanner in both sextant and complete-arch scenarios. Furthermore, time of scanning was evaluated and correlated with trueness and precision.

Antibacterial properties of copper iodide-doped glass ionomer-based materials and effect of copper iodide nanoparticles on collagen degradation.

Objectives: This study investigated the antibacterial properties and micro-hardness of polyacrylic acid (PAA)-coated copper iodide (CuI) nanoparticles incorporated into glass ionomer-based materials, and the effect of PAA-CuI on collagen degradation.

Materials And Methods: PAA-CuI nanoparticles were incorporated into glass ionomer (GI), Ionofil Molar AC, and resin-modified glass ionomer (RMGI), Vitrebond, at 0.263 wt%.

Evaluation of the Marginal Fit of CAD/CAM Crowns Fabricated Using Two Different Chairside CAD/CAM Systems on Preparations of Varying Quality.

Purpose: This study evaluated the marginal gap of crowns fabricated using two new chairside computer-aided design/computer-aided manufacturing systems on preparations completed by clinicians with varying levels of expertise to identify whether common preparation errors affect marginal fit. The null hypothesis is that there is no difference in the mean marginal gaps of restorations of varying qualities and no difference in the mean marginal gap size between restorations fabricated using the PlanScan (D4D, Richardson, TX, USA) and the CEREC Omnicam (Sirona, Bensheim, Germany).

Material And Methods: The fit of 80 lithium disilicate crowns fabricated with the E4D PlanScan or CEREC Omnicam systems on preparations of varying quality were examined for marginal fit by using the replica technique.

Utilizing self-assessment software to evaluate student wax-ups in dental morphology.

Traditionally, evaluating student work in preclinical courses has relied on the judgment of experienced clinicians utilizing visual inspection. However, research has shown significant disagreement between different evaluators (interrater reliability) and between results from the same evaluator at different times (intrarater reliability). This study evaluated a new experimental software (E4D Compare) to compare 66 student-produced tooth wax-ups at one U.

Incorporation of bactericidal poly-acrylic acid modified copper iodide particles into adhesive resins.

Objectives: This study aimed to investigate incorporation of polyacrylic acid (PAA) coated copper iodide (CuI) nanoparticles into dental adhesives, and to evaluate for the first time, their antibacterial properties, bond strength and cytotoxicity.

Methods: PAA-CuI nanoparticles were synthesized and incorporated into commercially available adhesives Optibond XTR (1.0mg/ml) and XP Bond (0.

Dental students' opinions of preparation assessment with E4D compare software versus traditional methods.

The aim of this study was to evaluate dental students' opinions regarding the utilization of a new grading software program for student self-assessment and a faculty-grading tool in a preclinical course. Using surface mapping technology, this program, called E4D Compare, yields a digital model of a student's preparation that is color-coded to show deficient areas. The program has now been used for two years at the James B.

E4D compare software: an alternative to faculty grading in dental education.

The traditional method of evaluating student tooth preparations in preclinical courses has relied on the judgment of experienced clinicians primarily utilizing visual inspection. At times, certain aids such as reduction matrices or reduction instruments of known dimension are used to assist the evaluator in determining the grade. Despite the skill and experience of the evaluator, there is still a significant element of uncertainty and inconsistency in these methods.

Predicting marginal fit of CAD/CAM crowns based on the presence or absence of common preparation errors.

Statement Of Problem: Confusion exists as to what constitutes an ideal ceramic crown preparation and whether certain deviations from the ideal can affect the marginal fit of the milled restoration.

Purpose: This study evaluated the marginal gap of E4D crowns fabricated on preparations completed by clinicians with varying levels of expertise to identify whether common errors affect marginal fit.

Material And Methods: The fit of 75 crowns fabricated with the E4D system on preparations of varying quality were examined for marginal fit by using the replica technique.

Determination of structural building blocks in heavy petroleum systems by collision-induced dissociation Fourier transform ion cyclotron resonance mass spectrometry.

Collision-induced dissociation Fourier Transform ion cyclotron resonance mass spectrometry (CID-FTICR MS) was developed to determine structural building blocks in heavy petroleum systems. Model compounds with both single core and multicore configurations were synthesized to study the fragmentation pattern and response factors in the CID reactions. Dealkylation is found to be the most prevalent reaction pathway in the CID.