Wook Jin Seong

Bio: Wook Jin Seong is an academic researcher from University of Minnesota. The author has contributed to research in topics: Implant & Dental implant. The author has an hindex of 14, co-authored 30 publications receiving 1262 citations.

Current ceramic materials and systems with clinical recommendations: A systematic review

Abstract: Statement of problem Developments in ceramic core materials such as lithium disilicate, aluminum oxide, and zirconium oxide have allowed more widespread application of all-ceramic restorations over the past 10 years. With a plethora of ceramic materials and systems currently available for use, an overview of the scientific literature on the efficacy of this treatment therapy is indicated. Purpose This article reviews the current literature covering all-ceramic materials and systems, with respect to survival, material properties, marginal and internal fit, cementation and bonding, and color and esthetics, and provides clinical recommendations for their use. Material and methods A comprehensive review of the literature was completed seeking evidence for the treatment of teeth with all-ceramic restorations. A search of English language peer-reviewed literature was undertaken using MEDLINE and PubMed with a focus on evidence-based research articles published between 1996 and 2006. A hand search of relevant dental journals was also completed. Randomized controlled trials, nonrandomized controlled studies, longitudinal experimental clinical studies, longitudinal prospective studies, and longitudinal retrospective studies were reviewed. The last search was conducted on June 12, 2007. Data supporting the clinical application of all-ceramic materials and systems was sought. Results The literature demonstrates that multiple all-ceramic materials and systems are currently available for clinical use, and there is not a single universal material or system for all clinical situations. The successful application is dependent upon the clinician to match the materials, manufacturing techniques, and cementation or bonding procedures, with the individual clinical situation. Conclusions Within the scope of this systematic review, there is no evidence to support the universal application of a single ceramic material and system for all clinical situations. Additional longitudinal clinical studies are required to advance the development of ceramic materials and systems.

Correlations between physical properties of jawbone and dental implant initial stability.

Abstract: Statement of problem There is confusion in the literature about how physical properties of bone vary between maxillary and mandibular regions and which physical properties affect initial implant stability. Purpose The purpose of this study was to determine correlations between physical properties of bone and initial implant stability, and to determine how physical properties and initial stability vary among regions of jawbone. Material and Methods Four pairs of edentulous maxillae and mandibles were retrieved from fresh human cadavers. Six implants per pair were placed in different anatomical regions (maxillary anterior, right and left maxillary posterior, mandibular anterior, right and left mandibular posterior). Immediately after surgery, initial implant stability was measured with a resonance frequency device and a tapping device. Implant surgeries and initial stability measurements were performed within 72 hours of death. Elastic modulus (EM) and hardness were measured using nano-indentation. Composite apparent density (cAD) was measured using Archimedes' principle. Bone-implant contact percentage and cortical bone thickness were recorded histomorphometrically. Mixed linear models and univariate-correlation analyses were used (α=.05). Results Generally, mandibular bone had higher initial implant stability and physical properties than maxillary bone. Initial implant stability was higher in the anterior region than in the posterior. EM was higher in the posterior region than in the anterior; the reverse was true for cAD. Conclusions Of the properties evaluated, cAD had the highest correlation with initial implant stability (r=0.82). Both physical properties of bone and initial implant stability differed between regions of jawbone. (J Prosthet Dent 2009;101:306–318)

Accuracy of friction-style and spring-style mechanical torque limiting devices for dental implants.

Abstract: Statement of problem Accurate delivery of torque to implant prosthetic screws is critical to generate ideal preload in the screw joint and offer protection against screw loosening. Mechanical torque limiting devices (MTLDs) are available in 2 different styles that have not been compared for accuracy. Purpose The purpose of this study was to determine the accuracy of friction-style and spring-style MTLDs in delivering target torque values. Material and methods Five MTLDs from each of 6 different implant manufacturers (n=30) were selected to determine their accuracy relative to their target torque values. All MTLDs were new; 3 types were of the friction style while 3 were of the spring style. To measure the output of each MTLD, a digital torque gauge with a 3-jaw chuck to hold the driver was used. Force was applied to the MTLD until either the friction style released at a precalibrated torque value or the spring style flexed to a precalibrated limit. The peak torque value registered by the digital torque gauge was recorded and the procedure was repeated 50 times for each MTLD. Statistical analysis used repeated-measures ANOVA (α=.05) to assess the accuracy of the MTLDs in delivering target torque values. Results Both the mean absolute difference (ABSDIFF) and the mean percentage deviation (PERDEV) between measured torque values and target torque values differed significantly ( P Conclusions Within the limitations of this study, MTLDs that use spring-style components are significantly more accurate than those that use friction-style components in achieving their target torque values. (J Prosthet Dent 2008;100:86-92)

Systematic review of the survival rate and the incidence of biological, technical, and aesthetic complications of single crowns on implants reported in longitudinal studies with a mean follow-up of 5 years

Abstract: Objective To assess the 5-year survival of implant-supported single crowns (SCs) and to describe the incidence of biological, technical, and aesthetic complications. The focused question was: What is the survival rate of implants supporting single crowns and implant-supported crowns with a mean follow-up of 5 years and to which extent do biological, technical, and aesthetic complications occur? Methods A Medline search (2006–2011) was performed for clinical studies focusing on implant-supported SCs with a mean follow-up of at least 5 years. The search was complemented by an additional hand search and the inclusion of 24 studies from a previous systematic review (Jung et al. 2008a). Survival and complication rates were analyzed using random-effects Poisson's regression models to obtain summary estimates of 5- and 10-year proportions. Results Forty-six studies derived from an initial search count of 1083 titles and the complementary publications from the previous systematic review (Jung et al. 2008a) were selected and the data were extracted. Based on the meta-analysis, survival of implants supporting SCs at 5 years amounted to 97.2% (95% CI: 96.3–97.9%), and at 10 years amounted to 95.2% (95% CI: 91.8–97.2%). The survival of implant-supported SCs was 96.3% (95% CI: 94.2–97.6%) after 5 years and 89.4% (95% CI: 82.8–93.6%) after 10 years. For biological complications, a 5-year cumulative soft tissue complication rate of 7.1% (95% CI: 4.4–11.3%) and a cumulative complication rate for implants with bone loss >2 mm of 5.2% (95% CI: 3.1–8.6%) were calculated. Technical complications reached a cumulative incidence of 8.8% (95% CI: 5.1–15.0%) for screw-loosening, 4.1% (95% CI: 2.2–7.5%) for loss of retention, and 3.5% (95% CI: 2.4–5.2%) for fracture of the veneering material after 5 years. The cumulative 5-year aesthetic complication rate amounted to 7.1% (95% CI: 3.6–13.6%). Conclusions The outcomes of the meta-analysis demonstrated high implant survival rates for both the single tooth implants and the respective single crowns after 5 and 10 years. However, technical, biological, and aesthetic complications were frequent.

Advances in Biomaterials for Drug Delivery.

Abstract: Advances in biomaterials for drug delivery are enabling significant progress in biology and medicine. Multidisciplinary collaborations between physical scientists, engineers, biologists, and clinicians generate innovative strategies and materials to treat a range of diseases. Specifically, recent advances include major breakthroughs in materials for cancer immunotherapy, autoimmune diseases, and genome editing. Here, strategies for the design and implementation of biomaterials for drug delivery are reviewed. A brief history of the biomaterials field is first established, and then commentary on RNA delivery, responsive materials development, and immunomodulation are provided. Current challenges associated with these areas as well as opportunities to address long-standing problems in biology and medicine are discussed throughout.

Resin-composite Blocks for Dental CAD/CAM Applications

Abstract: Advances in digital impression technology and manufacturing processes have led to a dramatic paradigm shift in dentistry and to the widespread use of computer-aided design/computer-aided manufacturing (CAD/CAM) in the fabrication of indirect dental restorations. Research and development in materials suitable for CAD/CAM applications are currently the most active field in dental materials. Two classes of materials are used in the production of CAD/CAM restorations: glass-ceramics/ceramics and resin composites. While glass-ceramics/ceramics have overall superior mechanical and esthetic properties, resin-composite materials may offer significant advantages related to their machinability and intra-oral reparability. This review summarizes recent developments in resin-composite materials for CAD/CAM applications, focusing on both commercial and experimental materials.