
Edmond PowThe University of Hong Kong | HKU · Faculty of Dentistry
Edmond Pow
BDS, MDS, PhD
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145
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Publications
Publications (145)
This novel hybrid single-double-single barrel (1-2-1) design for fibula free flap reconstruction addresses the unique challenges presented by Brown Class III mandibular defects, which involve long-span defects at both bodies of the mandible and the chin. The importance of this design lies in its ability to overcome the limitations of traditional ap...
Objectives:
This study aimed to investigate the colour accuracy of digital photographs captured by a single-lens reflex (SLR) camera and a smartphone camera in a clinical setting.
Methods:
Dentate subjects were recruited, and their maxillary anterior teeth were photographed along with a colour target and a dental shade guide. There were eight gr...
Objective:
To explore and analyse the perspective of patients undergoing and recovering from nasopharyngeal carcinoma (NPC) therapy.
Methods:
Thirty-three NPC patients at different stages of treatment were enrolled. Seven were actively undergoing treatment, 13 were immediately post-treatment, and 13 were long-term. Patients were interviewed usin...
Objectives:
This study utilised an Artificial Intelligence (AI) method, namely 3D-Deep Convolutional Generative Adversarial Network (3D-DCGAN), which is one of the true 3D machine learning methods, as an automatic algorithm to design a dental crown.
Methods:
Six hundred sets of digital casts containing mandibular second premolars and their adjac...
Objective:
The purpose of this study was to evaluate the use of magnifying loupes (x2.5) on the quality of tooth preparation for complete coverage crowns; performed by predoctoral students using an objective and quantitative digital method.
Material and methods:
Forty-two predoctoral students were randomly assigned into 2 groups to perform tooth...
Statement of problem
Computer-aided design and computer-aided manufacturing (CAD-CAM) technology has greatly improved the efficiency of the fabrication of dental prostheses. However, the design process (CAD stage) is still time-consuming and labor intensive.
Purpose
The purpose of this feasibility study was to investigate the accuracy of a novel a...
Objective:
To seek dentine analogue materials in combined experimental, analytical, and numerical approaches on the mechanical properties and fatigue behaviours that could replace human dentine in a crown fatigue laboratory test.
Methods:
A woven glass fibre-filled epoxy (NEMA grade G10; G10) and a glass fibre-reinforced polyamide-nylon (30% gla...
Objective
This in vitro study aimed to investigate enamel wear against 3 monolithic ceramics using 2 methods of measurement.
Methods
Three groups of standard flat monolithic ceramic specimens including zirconia-reinforced lithium silicate glass (Vita Suprinity, VITA Zahnfabrik), yttria-stabilised tetragonal zirconia (Lava Esthetic Zirconia), and l...
This study aimed to compare the occlusal morphology and fracture behavior of lithium disilicate ceramic dental crowns on 12 human participants' premolar #45 designed by a knowledge-based AI (CEREC, biogeneric individual function, BI) and different human personnel (experienced technician, TD, and trained dental students, AD) using CAD software. Digi...
Objective:
To assess the marginal and bacterial microleakage in zirconia and CAD-CAM or cast Co-Cr implant abutments.
Methods:
Sixty-four conical connection implants with their respective abutments were divided into four groups (Co-Cr (milled, laser-sintered and cast) and Zirconia (milled)). All specimens were subjected to a chewing simulation a...
Purpose:
To investigate the error accumulation and distribution through various stages of the digital workflow for complete-arch implant-supported framework fabrication.
Materials and methods:
A resin model of edentulous maxilla with 6 dental implants was scanned using an intraoral scanner for 10 times (Complete-digital group). Ten conventional...
The aim of this study was to investigate the effects of supporting dies with different mechanical properties on the fracture strengths and failure modes of monolithic zirconia crowns, and identify a suitable die material for testing high-strength ceramic restorations. Thirty six dies from teeth, porous titanium and composite-resin with 36 zirconia...
Purpose:
To determine and compare the accuracy and reliability of shade matching using the conventional and smartphone virtual methods.
Materials and methods:
A phantom head with both maxillary central incisors removed was set up. A central incisor of various standard shades was inserted into the phantom head. Five undergraduate and five postgra...
Purpose/Aim
This study aimed to evaluate single crown restorations generated by CEREC biogeneric function, designed by experienced dental technician, and designed by dental student using a dental CAD software. Occlusal morphological parameters were evaluated by superimposing and analyzing the digital datasets, while fracture resistance was assessed...
Objectives
To compare 2 implant scan bodies with different geometry on the accuracy of the virtual alignment process in the digital workflow.
Materials and Methods
A master model of the edentulous maxilla with 6 implants and multi-unit abutments (MUA) inserted was fabricated. Six dome-shaped and cuboidal scan bodies were mounted on the MUAs respec...
Objectives
The aim of this in-vitro study was to compare the virtual techniques for registering single-implant position to the physical gold standard using a universal-coordinate system.
Materials and methods
Thirty dentate maxillary resin models with a dental implant inserted in the incisor region were prepared. On each model, a tooth-supported a...
Objectives
To develop a novel auxiliary device for improving the accuracy of intraoral implant scanning in the complete-edentulous arch.
Materials and methods
A standard model of edentulous maxilla with 6 dummy implants was prepared. Scan bodies were attached to the model, which was scanned by a laboratory scanner. A simulated mucosa (Group 0), a...
Material research in tissue engineering forms a vital link between basic cell research and animal research. Periodontal ligament cells (PDLCs, P) from the tooth have an osteogenic effect, whereas endothelial progenitor cells (EPCs, E) assist in neovascularization. In the present study, the interaction of PDLCs and EPCs with Tantalum (Ta, I) discs,...
The aim of this in vitro study was to investigate the microgaps at the implant-abutment interface when zirconia (Zr) and CAD/CAM or cast Co-Cr abutments were used.
Methods:
Sixty-four conical connection implants and their abutments were divided into four groups (Co-Cr (milled, laser-sintered and castable) and Zirconia (milled)). After chewing sim...
Background
The fit of implant‐supported prostheses is of prime importance for the long‐term success of implant therapy.
Purpose
This systematic review aimed to evaluate recent evidence on current techniques for assessing implant‐framework misfit, its associated strain/stress, and whether these misfits are related to mechanical, biological, and cli...
Background:
Conventional freehand immediate placement of dental implants is technically challenging in the jaw reconstructive surgery. Computer-aided surgery might be the best solution, however, there has not been any standard approach to ensure the accuracy and efficiency of simultaneous dental implants in fibula flap jaw reconstruction.
Purpose...
Statement of problem
Lithium disilicate (LD) is a popular dental ceramic and has been a focus of dental research. Nevertheless, a quantified literature analysis focusing on the research of lithium disilicate is lacking.
Purpose
The purpose of this bibliometric analysis was to review the progress of research into lithium disilicate in dentistry, i...
Objectives:
To compare the accuracies of 4 laboratory scanners using a new custom-made block for complete-arch implant rehabilitation.
Materials and methods:
A block comprised 4 cylinders, with 2 in the anterior (0° angulation) and 2 in the posterior region (45° distal angulation) (Experimental group) and a standard block with 2 parallel cones i...
Highlights
•"Blood-island" like cell clusters is not the only pattern in the emergence of EPCs from MNCs during culturing.
•We identified two more distinct attributes, biphasic EPCs and de novo EPCs.
•EPCs might coexist as a subset in the MNCs.
•CD34+CD133+ cells from both rabbit and human primary endothelial cell culture can give rise to EPCs....
Sodium hypochlorite (NaOCl), an effective endodontic irrigant against Enterococcus faecalis (EF), is harmful to periapical tissues. Natural pineapple-orange eco-enzymes (M-EE) and papaya eco-enzyme (P-EE) could be potential alternatives. This study aimed to assess the antimicrobial efficacy of M-EE and P-EE at different concentrations and fermentat...
Purpose:
To systematically review the current evidence on clinical and patient-reported outcomes of implant-supported palatal obturator prostheses.
Materials and methods:
An electronic search of the PubMed, Web of Science, and Cochrane databases was carried out in June 2019. The titles and abstracts of all articles were screened by two independe...
Background
Validated animal models form the cornerstone of in vivo clinical trials. Rabbits, for instance, have been widely used in musculoskeletal research, but there is a lack of knowledge regarding endothelial progenitor cells (EPCs) obtained from their peripheral blood (PB). Further, there is an ambiguity regarding the origin of EPCs in blood....
Objectives
To evaluate the reproducibility of complete arch scanning with multiple implant scan bodies using a laboratory scanner.
Methods
A master model of edentulous maxillary arch with 6 implants was fabricated. PEEK scan bodies were inserted into the model and consecutively scanned using a dental laboratory scanner (N = 10, Group C). Another 1...
Objectives
This study was conducted to examine the tooth wear status of nasopharyngeal-carcinoma (NPC) patients who had received radiotherapy at least 5-year previously, and to investigate the salivary parameters that may be associated with the tooth wear.
Methods
Tooth wear status of NPC survivors were clinically assessed using the Exact Tooth We...
Purpose/Aim: The objective of this preliminary study was to compare the degree of microleakage and the t at the abutment-implant interface of different cobalt-chromium abutments, depending on manufacturing tech- nique, compared to zirconia abutments. Materials and Methods: In this transversal in vitro study, the t and microleakage of a total of 60...
Introduction:
Candida albicans possesses the ability to switch rapidly between yeast to hyphal forms. Hyphal formation is a remarkable pathogenic characteristic, which allows C. albicans to invade into host cells.
Objectives:
This study was to investigate the role of the C. albicans SAP9 gene in hyphal formation and invasion ability.
Methods:...
Purpose
To investigate the correlation of anterior overbite with the sagittal root position (SRP) and buccal bone thickness (BBT) of the maxillary anterior teeth.
Methods
Cone-beam computed tomography (CBCT) data of southern Chinese patients who underwent CBCT examinations between November 2016 and December 2016 were collected. The anterior overbi...
Aim
The aim of the present study was to investigate the initial stem cell and pre‐osteoblast cell adhesion and oxidative response on zirconia in comparison with titanium.
Methods
Human dental pulp stem cells (DPSC) and murine pre‐osteoblasts (MC3T3‐E1) cells were cultured on zirconia and titanium surfaces, and at 3‐, 12‐, and 24‐hour intervals, ce...
Aim
The objective of this laboratory study was to evaluate the adhesion strength of 5 commercially available dental silane coupling agents (ESPE Sil™, Bis-silane™, Clearfil™ Ceramic Primer, VITASIL® and Cimara®) bonded with an experimental bis-GMA resin to silica-coated titanium.
Materials and methods
The silanes were applied onto tribochemically...
A wide range of commonly-performed dental procedures, from operative caries removal, crown preparation, filling, to Orthodontia, could potentially benefit from robotic assistance or enhancement. Despite the wide applicability, dental robots have received far less research attention in comparison with surgical robots in general, with the vast majori...
With the discovery of endothelial progenitor cells (EPCs) in the late 1990s, a paradigm shift in the concept of neoangiogenesis occurred. The identification of circulating EPCs in peripheral blood marked the beginning of a new era with enormous potential in the rapidly transforming regenerative field. Overwhelmed with the revelation, researchers ac...
The Objective of this research protocol is compare the degree of microleakage and fit of chrome-cobalt frameworks, depending on their manufacturing technique, against zirconia abutments.
A tansversal IN VITRO comparative study of 60 titanium implants, 15 cobalt-chrome cast frameworks, 15 sintered cobalt-chrome frameworks and 15 milled cobalt-chrom...
Objectives:
Tooth shade is crucial to patient satisfaction in aesthetic dentistry. Two-dimensional (2D) clinical photographs have been widely used to record patients' tooth shade for creation of beautiful smile. However, in the digital workflow, 3D virtual teeth models in open file format contain only mesh information with no colour. This paper de...
This invention is about a novel image registration. This rigid registration is based on
multiple surfaces arranged in a 3D relationship in the Cartesian coordinate system
through a fiducial marker. In comparison to surface-based registration, this registration
process provides more accurate registration or requires a smaller fiducial marker for the...
Background:
Human periodontal ligament stem cells (hPDLSCs) have been shown to be a reliable source of mesenchymal stem cells (MSCs). On the other hand, rabbits have been commonly used in preclinical trials for musculoskeletal research. However, there is a lack of sufficient data on using rabbit periodontal ligament stem cells (rPDLSCs) for regene...
Purpose: The aim of this study was to investigate and quantify the effect of preparation design parameters on a premolar restored with two different CAD/CAM ceramic crowns by three-dimensional finite element analysis (FEA).
Methods: A restored human first premolar was digitized by a micro-CT scanner and a 3D model was created by a medical image pro...
The aim of this research was to investigate the effect of preparation design parameters of a premolar restored with ceramic crowns. Twelve models were created considering three convergence angles (6°, 12° and 20°), two preparation heights (3.1 mm and 4.1 mm), and two CAD/CAM ceramics (IPS e.max® CAD and enamic®) using micro-CT images and Mimics sof...
Objectives:
The purpose of this study was to estimate the fatigue life of premolars restored with two dental ceramics, lithium disilicate (LD) and polymer infiltrated ceramic (PIC) using the numerical method and compare it with the published in vitro data.
Methods:
A premolar restored with full-coverage crown was digitized. The volumetric shape...
The aim of this study was to evaluate fatigue life of premolars restored with two contemporary dental ceramics, lithium disilicate e.max® CAD (LD) and polymer-infiltrated ceramic Enamic® (PIC), using numerical methods. A premolar restored with full-coverage crown was digitized with a micro-CT scanner. After reconstruction of the 2D images, the toot...
2nd ITI Study Club in Mashhad
Accurate articulator-mounted casts are essential for occlusion analysis and for fabrication of dental prostheses. Although the axis orbital plane has been commonly used as the reference horizontal plane, some clinicians prefer to register the horizontal plane with a spirit level when the patient is in the natural head position (NHP) to avoid anatom...
Purpose:
The aim was to investigate the effect of preparation design parameters of a premolar restored with two different CAD/CAM ceramic crowns by using a numerical method.
Materials and methods:
By digitizing a restored first maxillary premolar with a micro-CT scanner and using a medical image processing software (Mimics™), a 3D model was create...
Purpose
The aim of this study was to investigate and compare the fatigue strength of maxillary premolars restored with two CAD/CAM ceramics, lithium disilicate e.max® CAD (LD) and polymer-infiltrated ceramic Enamic® (PIC).
Materials and methods
Twenty extracted maxillary premolars were selected and prepared for full-coverage restoration (IRB number...
Aim:
The aim of the present study was to compare the accuracy of radiographic measurements for dental implants planning using cone-beam computed tomography (CBCT) and helical computed tomography (HCT).
Methods:
Six pig ribs were wrapped by putty impression material, with radiographic markers placed. Two CBCT and an HCT were taken following the s...
The aim of this study was to determine the fatigue strength of two contemporary crown ceramics, lithium disilicate e.max® CAD (LD) and polymer-infiltrated ceramic Enamic® (PIC) and examine their failure mode. Twenty extracted human maxillary premolars were divided into two groups. The teeth were prepared and restored with either LD or PIC crowns. T...
Converting the patient’s clinical information into the virtual world is a prerequisite for the computer-aided design and computer-aided manufacturing (CAD-CAM) of dental restorations. This article describes a modified facebow which facilitates the radiation-free registration of the maxillary teeth to a 3-dimensional face image for transfer to a vir...
Objectives:
To investigate the salivary anionic changes of patients with nasopharyngeal carcinoma (NPC) treated by radiotherapy.
Material and methods:
Thirty-eight patients with T1-4, N0-2, M0 NPC received conventional radiotherapy. Stimulated whole saliva was collected at baseline and 2, 6 and 12 months after radiotherapy. Salivary anions level...
Cartesian coordinates define on a physical cubic corner (CC) with the corner tip as the origin and three corresponding line angles as (x, y, z)-axes. In its image (virtual) domains such as these obtained by cone-beam computed tomography (CBCT) and optical surface scanning, a single coordinate can then be registered based on the CC. The advantage of...
AIM AND PURPOSE
The aim of this research was to investigate the flexural strength and the Young’s modulus of three different machinable dental ceramics: zirconia Cercon (Degudent, Hanau, Germany), glassceramic IPS e.max CAD (Ivoclar Vivadent, Schaan, Liechtenstein), and polymerinfiltrated hybrid ceramic Enamic (VITA Zahnfabrik, Bad Säckingen, Ger...
Objectives
New CAD/CAM ceramic-based dental prosthesis has become a popular choice for their advantages, e.g. more materials availability, more aesthetics, higher strength and biocompatibility, and saving processing time, in comparison to other kinds of restorations. Measuring their static and dynamic mechanical properties could help dentists to ch...
Objective
. The present study aimed to investigate the effect of fluoride-modified titanium surface on adhesion of irradiated osteoblasts.
Materials and Methods
. Fluoride-modified surface was obtained and the morphology, roughness, and chemical composition of the surface were evaluated by scanning electron microscopy, atomic force microscopy, and...
Fluorophlogopite glass ceramic (FGC) is a biocompatible, etchable, and millable ceramic with fluoride releasing property. However, its mechanical properties and reliability compared with other machinable ceramics remain undetermined.
The purpose of this in vitro study was to compare the mechanical properties of 3 commercially available millable cer...
Medical radiography is the use of radiation to " see through " a human body without breaching its integrity (surface). With computed tomography (CT)/cone beam computed tomography (CBCT), three-dimensional (3D) imaging can be produced. These imagings not only facilitate disease diagnosis but also enable computer-aided surgical planning/navigation. I...
Radiotherapy may compromise the integration of implant and cause implant loss. Implant surface modifications have the possibility of promoting cell attachment, cell growth, and bone formation which ultimately enhance the osseointegration process. The present study aimed to investigate the effects of calcium phosphate nanocrystals on implant osseoin...
The use of cone-beam computed tomography (CBCT) in medical field can help the clinicians to visualize the hard tissues in head and neck region via a cylindrical field of view (FOV). The images are usually presented with reconstructed three-dimensional (3D) imaging and its orthogonal (x-, y- and z- planes) images. Spatial relationship of the structu...
Objective: To investigate the effect of C. albicans SAP7 gene in induced endocytosis in Candida-epithelial cell interactions
Method: In this study, C. albicans sap7 mutant strain was constructed in our laboratory by a PCR – based gene disruption method. In the endocytosis assay, the number of C. albicans cells that were cell-associated with and e...
Background:
The majority of studies examining anionic composition in human saliva have focused on inorganic anions only, and accompanying organic anion concentration has often been overlooked in the development of artificial salivas. The purpose of this study was to examine the major organic anionic species profile of human saliva, with a view to...
Objective: To compare the accuracy of radiographic measurements using cone beam (CBCT) and helical computer tomography (CT).
Method: Six pig ribs with soft tissues were wrapped by putty impression material with radiographic markers placed. Two CBCTs and CT machines were used. Vertical and horizontal dimensions of the ribs were measured using the...
Molar-incisor hypomineralization (MIH) is a developmental enamel hypomineralized condition characteristically involving the first permanent molars and sometimes also the incisors. The affected teeth are predisposed to tooth surface loss (TSL) which may not only compromise the esthetics and function but also endanger the pulp and longevity of the te...
Introduction. The psychosocial and quality of life (QoL) of patients with deformed or missing ears are frequently compromised. The aim of this study is to develop innovative techniques using CAD/CAM technology in prosthetic auricular rehabilitation and provide improvement in the treatment outcomes, including their psychology and QoL. Methods. This...
Excessive movable tissue is a challenge in complete denture prosthetics. A modified impression technique is presented with polyvinyl siloxane impression material and a custom tray with relief areas and perforations in the area of the excessive movable tissue.
AimThe aim of the present study was to compare the effectiveness of DNA extraction using an extraction kit against the standard boiling technique for the detection of Epstein–Barr virus (EBV) DNA in nasopharyngeal carcinoma (NPC) patients. Methods
Stimulated whole saliva samples from newly-diagnosed NPC patients were collected. EBV DNA was extracte...
Oral rehabilitation after a mandibulectomy is a challenge for prosthodontists. This clinical report describes the management of a 54-year-old man, who, after a mandibulectomy, had rotation of the mandible, with a revascularized flap, followed by an implant-supported prosthesis and ceramic restorations.
Objective: To contrast and compare the effects of three surface coatings on the bond strength between zirconia and resin-cement.
Method: 32 pre-sintered zirconia discs (25 mm diameter, 1.5 mm thickness) were sectioned from zirconia blocks and polished under running water. All the samples were randomly divided into four experimental groups and tre...