An In Vivo Assessment of Different Mesenchymal Stromal Cell Tissue Types and Their Differentiation State on a Shape Memory Polymer Scaffold for Bone Regeneration.

A combined biomaterial and cell-based solution to heal critical size bone defects in the craniomaxillofacial area is a promising alternative therapeutic option to improve upon autografting, the current gold standard. A shape memory polymer (SMP) scaffold, composed of biodegradable poly(ε-caprolactone) and coated with bioactive polydopamine, was evaluated with mesenchymal stromal cells (MSCs) derived from adipose (ADSC), bone marrow (BMSC), or umbilical cord (UCSC) tissue in their undifferentiated state or pre-differentiated toward osteoblasts for bone healing in a rat calvarial defect model. Pre-differentiating ADSCs and UCSCs resulted in higher new bone volume fraction (15.

Comparison of flexural strength, marginal gap, and internal fit of milled and 3D-printed crown materials.

The purpose of this study was to compare the flexural strength, Weibull modulus (reliability), marginal gap, and internal fit (internal gap) of 4 materials for milling or 3-dimensional (3D) printing of definitive and provisional crowns: IPS e.max CAD (IEC), Paradigm MZ100 Block (PMB), Permanent Crown Resin (PCR), and Temporary CB Resin (TCR). Flexural strength was tested by subjecting sectioned milling blocks (IEC and PMB) or 3D-printed bars (PCR and TCR) to a 3-point bending test in a universal testing machine (n = 15 per material).

Microleakage and Fracture Resistance of "Infinity Edge" and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites.

Aim: This study aimed to evaluate the marginal microleakage and maximum occlusal fracture loads and fracture modes of two novel class II preparation designs, "infinity edge" and the "2.5 mm cusp reduction" preparations as compared to a traditional class II preparation without cuspal involvement.

Materials And Methods: Thirty extracted human mandibular molars were prepared for moderate-sized class II restorations with extensions into all occlusal grooves.

Effect of Milling Speed on the Properties of Zirconia Restorations.

Background: The purpose of this study was to evaluate the effect of milling speed on the surface roughness, marginal gap, marginal gap volume, marginal offset, and fracture load of zirconia restorations.

Material And Methods: A mandibular molar #30 typodont tooth was digitally scanned and an ideal crown preparation for a zirconia restoration was digitally created. A single master model die of the crown preparation was milled out of a resin material.

Efficacy of a chairside extraoral suction system in the reduction of aerosol contamination.

The dental setting is regarded as a high-risk environment for aerosol concentrations and transmission of respiratory infectious agents, especially in relation to the COVID-19 pandemic. Although a number of approaches and practices have evolved to reduce the spread of pathogens in the dental setting, the risk of airborne infection remains a concern. Several new extraoral suction (EOS) devices have been marketed recently; further investigation is warranted to determine their clinical effectiveness.

Novel chairside spectrometer-trained system for measuring the irradiance of light-curing units.

The purpose of this study was to compare the performances of 5 different instruments in measuring the irradiance of light-curing units (LCUs). A novel spectrometer-trained radiometer (CheckUp), 2 conventional chairside radiometers (Bluephase Meter I and Bluephase Meter II), and 2 devices considered to be gold standards for measuring irradiance (an integrating sphere spectrometer and a thermopile sensor) were used to evaluate 7 LCUs. The irradiance of each LCU was measured 10 times with each meter.

Evaluation of a Novel "Quad" Wavelength Light Curing Unit.

Background: This study investigated the properties (depth of cure, surface hardness, and volumetric shrinkage) of two composite restorative materials when polymerized with a novel "quad" spectrum (PinkWave) light-curing unit (LCU) compared to a tri-spectrum LCU (Valo Grand).

Material And Methods: One Valo Grand LCU was modified to be similar in irradiance to the PinkWave, and a second Valo Grand was utilized at the manufacturer's standard irradiant settings. Depth of cure was evaluated using the scraping technique (ISO 4049).

Biocompatible Nanocapsules for Self-Healing Dental Resins and Bone Cements.

Bone cements and dental resins are methacrylate-based materials that have been in use for many years, but their failure rates are quite high with essentially all dental resins failing within 10 years and 25% of all prosthetic implants will undergo aseptic loosening. There are significant healthcare costs and impacts on quality of life of patients. Self-healing bone cements and resins could improve the lifespan of these systems, reduce costs, and improve patient outcomes, but they have been limited by efficacy and toxicity of the components.

Comparative evaluation of mesenchymal stromal cell growth and osteogenic differentiation on a shape memory polymer scaffold.

Trauma-induced, critical-size bone defects pose a clinical challenge to heal. Albeit autografts are the standard-of-care, they are limited by their inability to be shaped to various defect geometries and often incur donor site complications. Herein, the combination of a "self-fitting" shape memory polymer (SMP) scaffold and seeded mesenchymal stromal cells (MSCs) was investigated as an alternative.

Efficacy of various decontamination methods and sterilization on contaminated and inoculated diamond-coated burs.

The objective of this study was to evaluate the efficacy of various decontamination methods and subsequent sterilization on contaminated and inoculated diamond-coated burs. One hundred forty new diamond-coated burs and 120 extracted human molars were utilized in this study. The burs were divided into 7 groups (n = 20): 1, positive control; 2, negative control; 3, new, unused burs; and 4 to 7, burs subjected to various combinations of cleaning methods (manual cleaning, use of a cleaning stone, and/or ultrasonic cleaning) after contamination.

Post-Cure Polymerization and Depth-of-Cure Behaviors of Dental Bulk-Fill Resin-Based Composites.

Introduction: Polymerization for modern dental resin-based composites (RBCs) not only occurs immediately upon light exposure but also continues for another 24 hours, well beyond after light is terminated. However, many questions still remain about the role of polymerization kinetics in optimizing the physical properties of a new RBC type-the bulk-fill.

Objective: The aim is to study the post-cure polymerization kinetics of bulk-fill RBCs and to compare their degree of polymeric conversion (DC) and depth-of-cure (DoC) with an incremental-fill, conventional RBC.

Hardness Development in Resin Composite Core Materials.

Purpose: To investigate the hardness characteristics of 13 contemporary resin core materials.

Materials And Methods: Specimens (n = 12) were fabricated using stainless steel molds with top surfaces of dual-cure products photopolymerized while additional groups were allowed to self-cure. Twelve Knoop hardness indentations 500 microns apart were obtained of photopolymerized top and bottom sample surfaces as well as the self-cured sample surface with the mean recorded as the representative sample hardness.

The effect of micro-mechanical signatures of constituent phases in modern dental restorative materials on their macro-mechanical property: A statistical nanoindentation approach.

This study utilized a statistical nanoindentation analysis technique (SNT) to measure the amount of organic and inorganic constituents of twenty different brands of dental resin-based composites (RBCs) and tested whether their macro-property such as flexural modulus could be approximated by the proportions of constituents' micromechanical signatures using various rules of mixtures. The probability density function (PDF) of constitutive moduli per RBC brand were measured for three groups, comprised of different indent arrays and inter-indent spacings. SNT was then applied to deconvolute each PDF, from which the effective filler (μ) and matrix (μ) moduli and filler (V) and matrix (V) volume fractions per RBC brand were computed.

Repair of resin-veneered polyetheretherketone after veneer fracture.

Statement Of Problem: If a composite resin-veneered polyetheretherketone (PEEK) restoration chips or fractures, a repair may be indicated. However, the most appropriate repair protocol for a composite resin-veneered PEEK restoration is unclear.

Purpose: The purpose of this in vitro study was to determine the efficacy of airborne-particle abrasion and/or a primer in the repair of composite resin-veneered PEEK prostheses.

Effect of high-irradiance light curing on exposure times and pulpal temperature of adequately polymerized composite.

This study investigated the effect of high-irradiance light-curing on exposure time and pulpal temperature of adequately-cured composite. Composite placed in a molar preparation was cured using high-irradiance light-curing units (Flashmax P3, Valo, S.P.

A Survey of US Air Force General Dentists Regarding Computer-aided Design/Computer-aided Manufacturing Usage.

Aim: The purpose of this study was to survey all United States Air Force (USAF) general dentists regarding their experience with computer-aided design/computer-aided manufacturing (CAD/CAM) while in a dental school. Dental school graduation year and location was compared to the type and amount of CAD/CAM training and clinical experience during dental school to better understand the differences and influence of this technology.

Materials And Methods: A survey consisting of six questions was sent through e-mail to 546 general dentists in the AF Dental Corps in 2018 of which 306 replied (56% response rate).

An Investigation of the Effect of Modifying and Reusing Impression Copings on Transfer of Implant Analog Position and Angulation.

Aim: The aim of this research was to determine whether sterilization and reutilization of impression copings had an impact on the accuracy of casts made for multiimplant restorations.

Materials And Methods: Four master casts embedded with five implant analogs were fabricated. Polyvinyl siloxane (PVS) impressions of the master cast with copings attached to the analogs were made and poured in dental stone.

Assessing Flexural Strength Degradation of New Cubic Containing Zirconia Materials.

Aim: Newer zirconia materials may have greater strength degradation under cyclic fatigue with increased yttria and cubic content. The purpose of this study was to evaluate the flexural strength (FS) degradation of newer zirconia materials compared to more traditional tetragonal zirconia materials.

Materials And Methods: The following materials were tested: two 3 mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) materials (Lava Plus, 3M ESPE; Katana ML, Kuraray), one 4 mol% partially stabilized zirconia (4Y-PSZ) material (Katana STML, Kuraray), two 5 mol% partially stabilized zirconia (5Y-PSZ) materials (Katana STML, Kuraray; Lava Esthetic, 3M ESPE), and one lithium disilicate material (IPS e.

Quality assurance: acceptance testing for digital dental intraoral sensors.

Objective: The aim of this study was to demonstrate the need for acceptance testing with digital dental intraoral sensors (DIOS) as the first step of a comprehensive quality assurance (QA) program.

Study Design: Five commercially available DIOS were tested by using a QA test phantom, satisfying the requirements for intraoral QA testing as specified in American Dental Association Technical Report No. 1094 (TR 1094).

Effect of high-speed sintering on the properties of a zirconia material.

Digital dentistry has led to the success of same-day, single-crown delivery. Unlike traditional convection furnaces for fabrication of zirconia materials, which typically require several hours to complete sintering, a dedicated high-speed sintering furnace that reportedly sinters zirconia in minutes is now available. Sintering times may increase or decrease based on the size of the restoration due to a novel interface between the chairside acquisition unit, milling unit, and furnace.

Polish retention of ceramic-polymer CAD/CAM materials.

New ceramic-polymer millable materials that may be less resistant to the abrasive effects of toothbrushing than glass-ceramic materials have been introduced recently. The purpose of this study was to evaluate the polish retention of ceramic-polymer materials after mechanical toothbrush abrasion. Four ceramic-polymer materials (Enamic, Lava Ultimate, CeraSmart, and Block HC) were compared to a lithium disilicate glass-ceramic material (IPS e.

Longitudinal Analysis of CAD/CAM Restoration Incorporation Rates into Navy Dentistry.

Introduction: Computer-aided design/computer-aided manufacturing (CAD/CAM) has gained increasing popularity since the first commercially viable dental system was introduced in the mid-1980s. Digitally milled dental restorations can be fabricated chairside in the course of one dental appointment, reducing time, cost, and manpower when compared with traditional laboratory-fabricated analog restorations. Clinical performance, physical properties, and esthetics of digital restorations have been shown to be comparable to traditional analog restorations.

Effect of high-intensity curing lights on the polymerization of bulk-fill composites.

Objectives: The purpose of this study was to investigate the effect of high-irradiance light-curing-units (LCUs) on the depth-of-cure (DoC) and degree-of-polymerization (DoP) of bulk-fill composites (BFCs).

Methods: The DoC of composites (Beautifil-Bulk, SHOFU; Filtek-Bulk-Fill, 3M ESPE; Tetric-EvoCeram-Bulk-Fill, Ivoclar; Sonic-Fill-2, Kerr; Venus-Bulk-Fill, Heraeus; Z250, 3M-ESPE) were measured according to ISO-4049 using high-irradiance LCUs (FlashMax-P3, CMS-Dental; SPEC3, Coltene) and conventional LCU (Paradigm, 3M-ESPE) for exposure times: 3/9-s, 3/20-s, and 10/20-s respectively. Using FTIR, the DoP per composite was measured at the bottom surface as a function of post-curing times for the LCUs at the same exposure times.

Fracture Resistance of Pressed and Milled Lithium Disilicate Anterior Complete Coverage Restorations Following Endodontic Access Preparation.

Purpose: This in vitro study evaluated the fracture resistance and clinical prognosis of anterior lithium disilicate crowns (e.max Press and e.max CAD), following endodontic access and repair.

A clinical study comparing digital radiography and near-infrared transillumination in caries detection.

Objective: The purpose of this study was to compare the effectiveness of detecting proximal carious lesions utilizing a new near-infrared transillumination (NIRTI) system (CariVu, Dexis) to traditional digital bitewing radiography (BWXR).

Materials And Methods: Thirty patients received four posterior BWXRs and all premolars and molars were individually imaged with the NIRTI device. Sixty-seven proximal carious lesions were classified based on their depth into enamel or dentin for both BWXR and NIRTI images.