Crowns

Tooth autotransplantation is one of the methods used for tooth loss rehabilitation in children. Premolars are usually used as autotransplants requiring esthetic alterations. The purpose of this paper is to present an innovative, alternative and inexpensive way to restore auto-transplanted teeth using the crown of the tooth of the recipient site. A seven-year-old male with a non-contributory medical history presented with an intrusion of his permanent maxillary right central incisor. The tooth underwent orthodontic extrusion using fixed appliances but eventually showed signs of ankylosis...

In traumatic dental injuries in children, due to a lack of maturity to cope with the situation, pain intolerance, amount of treatment procedure, and parental anxiety, simplified and non-invasive treatment procedures, such as biologic restorations, are useful. Using advanced adhesive material for fragment reattachment provides excellent esthetic results and a positive attitude from the patient and family. The purpose of this case report is to describe the biological restoration of a complicated crown-root fracture of a primary maxillary central incisor with the fragment reattachment technique...

OBJECTIVES: The aim of this study was to compare the effect of office bleaching of teeth bonded with Transbond XTTM  (3M Unitek, Monrovia, CA, USA) (TRXT) and the use of color change resistant Orthocem (FGM, Joinville, Brazil) in bracket bonding on coffee-induced enamel discoloration. MATERIALS AND METHODS: Eighty premolars were distributed in equal numbers (n = 20) to group 1 (TRXT + distilled water), group 2 (TRXT + coffee solution), group 3 (TRXT + coffee solution + bleaching), and group 4 (Orthocem + coffee solution)...

Introduction Dental caries is the most common reason for hospital admission of children aged 5-9 in the UK. Better management of caries in primary molars would reduce the number of children requiring treatment in hospitals; however, little research has been done into why primary care clinicians do not use an evidence-based approach to caries management for deciduous molars.Aims The aim of this paper is to identify the rationale behind caries management techniques used in primary care, as well as the choice of materials and long-term success of restorations placed...

OBJECTIVES: Multilayer monolithic zirconia (M-Zr) crowns can be engineered to achieve gradational translucency and color intensity. However, this modification may compromise the mechanical strength, raising concerns regarding the ability of M-Zr crowns to withstand occlusal stresses. The effects of M-Zr crown thickness on translucency and ability to endure occlusal forces were investigated at different tooth positions (incisors, premolars, and molars). The objective was to determine the minimal thickness of M-Zr crowns used in tooth preparation to meet aesthetic and functional demands...

Incorporation of secondary redox-inactive cations into heterobimetallic complexes is an attractive strategy for modulation of metal-centered redox chemistry, but quantification of the consequences of incorporating strongly Lewis acidic trivalent cations has received little attention. Here, a family of seven heterobimetallic complexes that pair a redox-active nickel center with La3+ , Y3+ , Lu3+ , Sr2+ , Ca2+ , K+ , and Na+ (in the form of their triflate salts) have been prepared on a heteroditopic ligand platform to understand how chemical behavior varies across the comprehensive series...

BACKGROUND: Restorative materials might significantly affect load transmission in peri-implant bone. The aim of the present study is to evaluate the shock absorption capacity of two different polymeric materials to be used for implant-supported prostheses. METHODS: A masticatory robot was used to compare the shock absorption capacity of veneered and non-veneered polyetherketoneketone (PEKK), Pekkton® ivory (Cendres+Mètaux), and the glass fiber-reinforced composite (GFRC), TRINIATM (Bicon)...

Fusarium crown rot (FCR) in wheat is a prevalent soil-borne disease worldwide and poses a significant threat to the production of wheat ( Triticum aestivum ) in China, with F. pseudograminearum being the dominant pathogen. Currently, there is a shortage of biocontrol resources to control FCR induced by F. pseudograminearum , along with biocontrol mechanisms. In this study, we have identified 37 strains of biocontrol bacteria displaying antagonistic effects against F. pseudograminearum from over 8000 single colonies isolated from soil samples with a high incidence of FCR...

In China, Fusarium pseudograminearum has emerged as a major pathogen causing Fusarium crown rot (FCR) and caused significant losses. Studies on the pathogen's properties, especially its mating type and trichothecene chemotypes, are critical with respect to disease epidemiology and food/feed safety. There are currently few available reports on these issues. This study investigated the species composition, mating type idiomorphs, and trichothecene genotypes of Fusarium spp. causing FCR in Henan, China. A significant shift in F...

This study aims to analyse, using a finite element analysis, the effects of Ti-base abutment height on the distribution and magnitude of transferred load and the resulting bone microstrain in the bone-implant system. A three-dimensional bone model of the mandibular premolar section was created with an implant placed in a juxta-osseous position. Three prosthetic models were designed: a 1 mm-high titanium-base (Ti-base) abutment with an 8 mm-high cemented monolithic zirconia crown was designed for model A, a 2 mm-high Ti-base abutment with a 7 mm-high crown for model B, and a 3 mm-high abutment with a 6 mm-high crown for model C...

The Asian longhorned beetle (ALB) causes substantial economic and ecological losses, thus, an environmentally friendly management strategy is needed. Here, we propose high trunk truncation (HTT), the removal of the above 200 cm portion of trees, as a sustainable management strategy to control ALB. To examine the hypothesis, an initial step involved the assessment of various biological characteristics of ALB. Subsequently, a controlled field experiment was carried out utilizing HTT. Finally, HTT was applied in two additional ALB infestation regions...

Density functional theory (DFT) and electron propagator theory (EPT) calculations were performed to study ground and excited electronic structures of alkali-metal (M) coordinated 9-crown-3, 24-crown-8, [2.1.1]cryptand, o -Me2 -1.1.1, and 36 Adamanzane complexes. Each complex bears an expanded electron in the periphery and occupies diffuse 1p-, 1d-, 1f-type molecular orbitals (or superatomic 1P, 1D, 1F orbitals) in excited electronic states. The calculated superatomic shell model of the M(9-crown-3)2 is 1S, 1P, 1D, 1F, 2S, 2P, 2D, 1G and it is held by all other complexes up to the studied 1F level...

Amylascus is a genus of ectomycorrhizal truffles within Pezizaceae that is known from Australia and contains only two described species, A. herbertianus and A. tasmanicus . Species of Amylascus are closely related to truffles ( Pachyphlodes , Luteoamylascus ) and cup fungi ( Plicariella ) from the Northern Hemisphere. Here we reevaluate the species diversity of Amylascus and related taxa from southern South America and Australia based on new morphological and molecular data. We identify previously undocumented diversity and morphological variability in ascospore color, ascospore ornamentation, hymenial construction, epithecium structure and the amyloid reaction of the ascus in Melzer's reagent...

Aim The study aims to evaluate the efficacy of different techniques for temporary crown fabrication in maintaining periodontal health and patient satisfaction, addressing a critical gap in the existing literature and informing evidence-based clinical practices. Materials and methods This study, conducted in accordance with CONSORT guidelines, was a parallel-group randomised trial conducted at a dental institute in India. In total, 36 participants aged 18-65 requiring anterior tooth region crowns were randomly assigned to three groups: direct (control), indirect (Test Group 1) and direct-indirect (Test Group 2) fabrication techniques...

OBJECTIVES: This study aimed to assess the influence of translucent monolithic versus bilayered crowns and whether the use of a CoCr base abutments affects the fatigue and fracture resistance of screwed implant-supported single crowns with external connections under mechanical cycling. MATERIALS AND METHODS: Fifty specimens were divided into groups: (1) metal-ceramic (MC) crown, (2) veneered zirconia crown (Zr), (3) veneered zirconia crown with a CoCr base abutment (ZrB), (4) monolithic translucent zirconia crown (MZr), and (5) monolithic translucent zirconia crown with a CoCr base abutment (MZrB)...

OBJECTIVES: this study aims to compare the clinical outcomes of traditional and digital crown extension guides in the aesthetic restoration of anterior teeth. Additionally, the study will analyze the differences in the results of various digital crown extension guides in anterior aesthetic restorations. METHODS: Sixty-two patients who required aesthetic restoration of their anterior teeth were selected for this study. The patients had a total of 230 anterior teeth and were randomly divided into three groups: a control group of 22 cases who received diagnostic wax-up with pressure film, an experimental group 1 of 20 cases who received 3D printed digital models with pressure film, and an experimental group 2 of 20 patients who received digital dual-positioning guides...

The coral predators, crown-of-thorns starfish (COTS, Acanthaster spp.) remain a major cause of extensive and widespread coral loss in Indo-Pacific coral reefs. With increased phylogenetic understanding of these seastars, at least five species appear to be present across different regions. We compare the feeding ecology of these species. Where acroporid corals are prevalent, Acanthaster spp. often exhibit a preference for these corals, with Porites being least preferred, as seen in most species including Acanthaster planci in the northern Indian Ocean and Acanthaster cf...

The redox state of the phthalocyanine in sandwich lanthanide complexes is crucial for their applications. In this work, we demonstrate that the cation-induced supramolecular assembly of crown-substituted phthalocyanine lanthanide complexes Ln[(15C5)4 Pc]2 can be used to control the redox state of the ligand simultaneously with the coordination sphere of the central metal. We achieve unprecedented redox switching of phthalocyanine ligands in a double-decker Gd(III) complex, resulting from the intramolecular inclusion of potassium cations between the decks with simultaneous twisting of the ligands (the skew angle between them decreases from 44...

In the design of dynamic supramolecular systems used in molecular machines, it is important to understand the binding preferences between the macrocycle and stations along the thread. Here, we apply 1H NMR spectroscopy to investigate the relative stabilities of a series of linear alkylammonium templated pseudorotaxanes with the general formula [H2NRR'][Cr7CoF8(O2CCH2tBu)16] by exchanging the cation in solution. Our results show that the pseudorotaxanes are able to exchange threads via a dissociative mechanism...

PURPOSE: To investigate the in vitro biocompatibility of human gingival fibroblasts with preformed paediatric crowns and resistance to acid exposure at levels that simulate the oral environment. METHODS: This laboratory study investigated primary HGFs viability, metabolic activity, cytotoxicity, and apoptotic events on preformed metal crown discs, composite resin-coated wells, and monolithic zirconia fragments at 24, 48, and 72 h using the ApoTox-Glo Triplex assay...