김선재 교수

PURPOSE: Four possible displacements of implant components from a patient model to a definitive cast were assessed to suggest a standard method of comparing the accuracies of implant impression techniques. MATERIALS AND METHODS: Two techniques for impression making were assessed: a nonsplinted open-tray technique and a light-curing resin splinted open-tray technique. A mandibular model with 5 parallel implants was fabricated. Five definitive casts were fabricated per technique. Using a computeri

PURPOSE: The purpose of this study was to investigate the early tissue response around three one-piece implant systems with different transmucosal designs. MATERIALS AND METHODS: Three one-piece dental implant systems with different profiles and surface roughnesses on the transmucosal portion were examined in the current study. The transmucosal portions were flared and machined (FM), concave and machined with microgrooves (CMG), or straight and anodic oxidized (SA). A total of 30 implants (10 of

BACKGROUND: The demand for implant dentistry, which includes customized abutments, is increasing. A lot of pollutions are generated on the customized abutment surface following milling procedure. This study evaluated the surface topography and cleanliness of customized abutments after cleaning procedures, which are simply applicable in the dental clinic. METHODS: Thirty computer-aided design and computer-aided manufacturing internal connection type titanium abutments were produced, milled, and r

Purpose: The aim of this study was to present a new method to analyze the three-dimensional accuracy of complete-arch dental impressions and verify the reliability of the method. Additionally, the accuracies of conventional and intraoral digital impressions were compared using the new method. Methods: A master model was fabricated using 14 milled polyetheretherketone cylinders and a maxillary acrylic model. Each cylinder was positioned and named according to its corresponding tooth position. Twe

PURPOSE: The objective of this study was to evaluate the influence of coping design modifications on maximum first principal stress (MPS) in a mathematical zirconia ceramic crown model. MATERIALS AND METHODS: For a nonlinear, 3D finite element analysis, a simplified tooth model was built on the basis of the average dimensions of mandibular second molars. Virtual tooth reduction was performed to model an abutment with a flat occlusal surface and 16° convergence angle between facing walls. The cem

The effect of microthreads at the implant neck on the amount of marginal bone resorption is controversial. This multicenter retrospective study compared the implant survival rate and amount of marginal bone resorption between two platform-switching internal connection implant systems with or without microthreads. Patient-related (age and sex), surgery-related (implant installation site, type, diameter, and length), and prosthesis-related (prosthesis type) data were collected from patient charts