Bock-Young Jung

Enhanced bone regeneration with a gold nanoparticle–hydrogel complex

Gold nanoparticles (GNPs) are widely used in diagnostics, drug delivery, biomedical imaging, and photo-thermal therapy due to their surface plasmon resonance, fluorescence, and easy-surface functionalization. According to recent studies, GNPs display a positive effect on the osteogenic differentiation of mesenchymal stem cells (MSCs) and MC3T3-E1 osteoblast-like cells. The aim of this study was to develop a new approach for bone tissue regeneration based on the utilization of a biodegradable hydrogel loaded with GNPs. We have used photo-curable gelatin hydrogels (Gel) in order to provide a proof of principle of GNPs in regeneration strategies for bone tissue repair. We have investigated the effects of these Gel-GNP composite hydrogels both in vitro and in vivo. The in vitro results showed that the hydrogels loaded with GNPs promote proliferation, differentiation, and alkaline phosphate (ALP) activities of human adipose-derived stem cells (ADSCs) as they differentiate towards osteoblast cells in a dose-dependent manner. Moreover, the in vivo results showed that these hydrogels loaded with high concentrations of GNPs had a significant influence on new bone formation. Through these in vitro and vivo tests, we found that the Gel-GNP can be a useful material for bone tissue engineering.

Diplopia after inferior alveolar nerve block anesthesia: Report of 2 cases and literature review

Inferior alveolar nerve block (IANB) anesthesia is one of the most common procedures in the dental clinic. Although this procedure is well known for its safety, complications can still occur. An ocular complication such as diplopia, loss of vision, or ophthalmoplegia is very rare, but once it happens, both the dentist and patient can be perplexed by the unexpected circumstance, and the doctor-patient trust may be harmed. We experienced 2 cases of diplopia after IANB anesthesia. This report describes the cause and diagnosis of the associated symptoms and includes a review of the literature.

Endodontic and Surgical Treatment of Root Damage Caused by Orthodontic Miniscrew Placement

INTRODUCTION Miniscrews are being increasingly used for anchorage control in orthodontics. Despite the concern over root damage caused by miniscrews, there are few reports of precise clinical evaluations and appropriate management of that damage. In the case presented herein, the root damage caused by the placement of miniscrews was repaired by root canal treatment and surgical intervention. METHODS A 44-year-old man received orthodontic treatment for intrusion of the left maxillary first molar with a miniscrew anchorage system. During that treatment, the miniscrews had fallen out and had to be reinserted more than 6 times in the same area. Two years later, the patient complained of a spontaneous pain in the maxillary left molar region. Although the patient received root canal treatment, intraoral sinus tracts could still be detected, and the patients discomfort persisted. Periradicular surgery revealed that the persistent infection was related to root surface damage caused by orthodontic miniscrew placement. Healing was achieved by a combination of root canal treatment and surgical intervention. RESULTS Scanning electron microscopy of the damaged distobuccal root apex revealed a mature biofilm consisting of a network of matrix that contained mostly rod-like and spherical bacteria. At a 12-month recall checkup, the patient was free of pain. A repeat periapical radiograph revealed reduction of the pretreatment radiolucent lesion. CONCLUSIONS More careful planning of miniscrew placement is necessary to lessen the danger of root damage. Furthermore, a precise evaluation of both root and pulpal damage and careful consideration of the choice of optimal treatment modality are needed.

Development of novel photopolymerizable hyaluronic acid/heparin-based hydrogel scaffolds with a controlled release of growth factors for enhanced bone regeneration

In this study, the effect of novel BMP-2-loaded photo-cured hydrogels on in vitro and in vivo osteogenesis were explored. The well-defined HA-heparin hydrogel was prepared by a photopolymerization of aminoethyl methacrylate (AEMA) grafted hyaluronic acid (HA) and AEMA-grafted heparin. Subsequently, the resulting hydrogels contained BMP-2 at different concentrations. First, a series of BMP-2-loaded hydrogels were characterized to determine their mechanical properties and release profiles. The results from rheology, swelling ratio, and release kinetics suggest that BMP-2 contained HA-g-Hhep gel (B/HA-g-Hhep gel) had sustained release during 4 weeks with minimal initial burst. Furthermore, the released BMP-2 maintained its biological activity. MTT and live/dead assays showed that the B/HA-g-Hhep gel had good biocompatibility to be used as a scaffold for bone regeneration. In vivo studies of B/HA-g-Hhep gel exhibited significantly enhanced osteogenesis, compared with other types of HA-heparin hydrogels. These excellent results indicated that B/HA-g-Hhep gel has a great potential for a controlled release of growth factor, leading to a good bone regeneration.

Preservation of Hypermobile Teeth by Establishing Posterior Occlusal Support Using Implant Prostheses: A 5-Year Follow-Up

For patients with periodontally compromised, hypermobile teeth, implant-supported fixed dental prostheses (FDPs) or removable dentures are often used after extracting mobile teeth. The loss of native teeth may carry social consequences, depending upon the patients age, state of health, and degree of social functioning. This report represents successful stabilization and preservation of questionable, hypermobile teeth that have been damaged by traumatic occlusion due to the loss of posterior support with a cross-arch splinted FDP, as well as the implementation of posterior support using implant-supported prostheses.

An esthetic appliance for the management of crown-root fracture: a case report

Orthodontic extrusion is usually performed by means of a fixed orthodontic appliance that utilizes arch wire attached to adjacent teeth and transfers the desired force by elastic from the wire to the root. However, clinicians often encounter cases where the bonding required for tooth traction is not possible because the adjacent teeth have been restored with ceramic or veneer. The purpose of this case report is to describe a modified orthodontic extrusion appliance that is useful when conventional orthodontic treatment is not possible. The modified appliance was fabricated using an artificial tooth, clear plastic sheeting, and a braided fiber-reinforced composite strip that covered adjacent teeth without bonding. It satisfied the esthetic and functional needs of the patient and established the optimal biologic width.

Alternative impression technique for multiple abutments in difficult case to control

BACKGROUND Even though excellent impression materials are now available for making accurate replication for hard and soft tissue, the numerous dentists have faced lots of obstacles in making simultaneous impressions of multiple abutments. CASE DESCRIPTION This article describes a modified method of tray fabrication using auto-polymerizing acrylic resin and impression technique for multiple prepared teeth in cases with limitations and difficulties in taking dental impressions. CLINICAL IMPLICATION This segmental tray technique has several advantages, including higher impression quality, fewer impressions, and being more comfortable for the patient and less stressful for the clinician.

Penetration Injury to Periorbital Area by Dental Laboratory Bur

Numerous reports have been published about occupational injury to dental health care workers including dentists, dental hygienists, and dental students; the incidence in dental students is higher than that in other dental professionals. 1-4 The incidence of penetration injury in dental students ranges from 1.97 to 12.5 per 10,000 visits. 1,5 The hand is the most frequently involved part of the body, and injury to the eyes or orbital area is quite rare. 6 However, eye injury is one of the most serious injuries in oral and maxillofacial trauma and as a dental occupational injury. 7 This case report describes a serious penetration injury to the orbital area resulting from inexperience in using a dental laboratory handpiece. The use of eye protection and instruction regarding proper manipulation of laboratory equipment should be emphasized.