Publications by authors named "Kwang-Shik Bae"

Endodontic implant pathology (EIP) refers to cases in which endodontic infections cause infections in adjacent implants, and vice versa. This case report demonstrates the successful resolution of two types of EIPs, implant endodontitis and endodontic implantitis, by endodontic intervention with surgical treatment. In case 1, the patient complained of tooth discomfort after implant placement in the adjacent tooth.

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Introduction: In dentistry, mineral trioxide aggregate (MTA) has been widely used for root perforation, retrograde filling, pulp capping and regenerative endodontics. Despite its superior sealing ability and biocompatibility, MTA has critical drawbacks regarding handling property such as sandy property, lacking cohesive properties and wash-out tendency. So, it is necessary to improve the fluidity of MTA in order to improve its handling properties.

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Introduction: This study used micro-computed tomographic imaging to compare the shaping ability of Mtwo (VDW, Munich, Germany), a conventional nickel-titanium file system, and Reciproc (VDW), a reciprocating file system morphologically similar to Mtwo.

Methods: Root canal shaping was performed on the mesiobuccal and distobuccal canals of extracted maxillary molars. In the RR group (n = 15), Reciproc was used in a reciprocating motion (150° counterclockwise/30° clockwise, 300 rpm); in the MR group, Mtwo was used in a reciprocating motion (150° clockwise/30° counterclockwise, 300 rpm); and in the MC group, Mtwo was used in a continuous rotating motion (300 rpm).

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The flowability of a root canal sealer is clinically important because it improves the penetration of the sealer into the complex root canal system. The purpose of this study was to compare the flowabilities of four root canal sealers, measured using the simple press method (ISO 6876), and their viscosities, measured using a strain-controlled rheometer. A newly developed, calcium phosphate-based root canal sealer (Capseal) and three commercial root canal sealers (AH Plus, Sealapex and Pulp Canal Sealer EWT) were used in this study.

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Ortho mineral trioxide aggregate (MTA) is a mineral aggregate newly developed for perforation repair, root end filling and pulp capping. The aim of this study was to investigate the levels of cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni) and zinc (Zn) in Ortho MTA and ProRoot MTA. A total of 0.

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Introduction: The aggregation of mixed bacterial flora into sessile biofilms on root canal surfaces can be one of the causes of persistent apical periodontitis. The aim of this study was to evaluate the antibacterial efficacy of human β-defensin-3 (HBD3) peptide on multispecies biofilms by using confocal laser scanning microscopy.

Methods: Actinomyces naeslundii, Lactobacillus salivarius, Streptococcus mutans, and Enterococcus faecalis were cultured in a peptone-yeast-glucose broth, and their culture suspensions were combined in equal proportions.

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Objective: The aim of this study was to investigate the effect of heat treatment on the cyclic fatigue resistance, thermal behavior and microstructural changes of K3 NiTi rotary instruments.

Materials And Methods: Twelve control (as-received) and 12 experimental (heat-treated) K3 NiTi rotary instruments were compared in this study. Those experimental K3 instruments were heated in a furnace for 30 min at 450°C and then quenched in water.

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In regard to biological properties of endodontic sealers, there are many characteristics that should be considered. The aim of this study was to examine the biological effects of new calcium phosphate-based root canal sealers, CAPSEAL I and CAPSEAL II (CPS), on human periodontal fibroblast cells by examining the expression levels of inflammatory mediators and to compare the effects of CPS on the viability and osteogenic potential of human osteoblast MG63 cells compared to those of other commercially available calcium phosphate sealers [Apatite Root Sealer type I (ARS I) and Apatite Root Sealer III (ARS III); Sankin Kogyo, Tokyo, Japan] and a zinc oxide eugenol-based sealer (Pulp Canal Sealer EWT [PCS EWT]; Kerr, Detroit, MI). The levels of IL-6 in the new CPS group (CAPSEAL I, II) were higher than those in the control and all experimental groups at all time points after 2 h.

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Introduction: The purpose of this study was to investigate the efficacy of laser-activated irrigation (LAI) of 1320-nm neodymium-doped:yttrium-aluminum-garnet (Nd:YAG) laser on sealer penetration into dentinal tubules in the presence of 5.25% sodium hypochlorite (NaOCl) or 17% ethylenediaminetetraacetic acid (EDTA).

Methods: The curved root canals (>20°) from 63 extracted human molars (negative control, n = 3) were prepared to size #30.

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Introduction: Recent studies have reported the color change and formation of precipitates containing para-chloroaniline (PCA) after a reaction of sodium hypochlorite (NaOCl) and chlorhexidine (CHX). Alexidine (ALX), a biguanide disinfectant similar to CHX, has greater affinity for bacterial virulence factors than CHX. This study determined by electrospray ionization mass spectrometry (ESI-MS) and scanning electron microscopy (SEM) whether the chemical interaction between ALX and NaOCl results in PCA or precipitates.

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Article Synopsis
  • - The study examines the safety of Ortho MTA and ProRoot MTA, two mineral trioxide aggregate products used in dental procedures, focusing on the levels of toxic heavy metals like arsenic, chromium, and lead.
  • - Methods involved using acids to digest samples of each MTA, with heavy metal concentrations analyzed using advanced spectrometry; statistical tests were applied to compare results.
  • - Findings showed that Ortho MTA had no detectable arsenic, chromium (Cr(6+)), or lead, while ProRoot MTA had low arsenic levels but more chromium; both products met safety standards for dental materials.
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Aim: To evaluate the safety and efficiency of novel ultrasonic scaler tips, conventional stainless-steel tips, and plastic tips on titanium surfaces.

Material And Methods: Mechanical instrumentation was carried out using conventional ultrasonic scalers (EMS, Nyon, Switzerland) with novel metallic implant tip (BS), a plastic-headed tip (ES), a plastic tip (PS) and a conventional stainless-steel tip (CS) on 10 polished commercially pure titanium disks (Grade II) per group. Arithmetic mean roughness (R(a) ) and maximum height roughness (R(y) ) of titanium samples were measured and dissipated power of the scaler tip in the tip-surface junction was estimated to investigate the scaling efficiency.

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Objective: The aim of this study was to compare the pHs and calcium ion releases of newly developed, calcium phosphate-based root canal sealers (Capseal I and II) with those of Sealapex (SA) and Sankin Apatite Root Sealer III (SARS III).

Study Design: Each material (n = 10) was mixed, inserted into polyvinyl chloride (PVC) tubes, and immersed in a vial containing deionized water. The control group consisted of empty PVC tubes (n = 10).

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Introduction: Recently, root canal shaping with reciprocating motion has been postulated to reduce the possibility of unexpected file fractures. However, there has been little information on the shaping capability of this reciprocating motion preparation technique. Therefore, the purpose of this study was to evaluate the shaping ability of reciprocating motion when compared with continuous rotation motion in curved root canals.

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Objective: The aim of this study was to investigate levels of matrix metalloproteinase-8 (MMP-8) and substance P (SP) in gingival crevicular fluid (GCF) during root canal treatment (RCT) of nonvital teeth.

Study Design: Patients scheduled for nonsurgical RCT were prospectively selected; all patients provided informed consent. GCF samples were collected from teeth scheduled for RCT and their contralateral teeth across 3 different time periods.

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Objective: The aim of this study was to investigate the types of canal configurations and the incidence of a second mesiobuccal (MB2) canal in Korean maxillary molar mesiobuccal (MB) roots by analyzing cone-beam computed tomographic (CBCT) images.

Study Design: Three-dimensional CBCT images of 458 maxillary first molars and 467 second molars from 276 Korean patients were analyzed to determine the incidence of an MB2 canal, the types of canal configurations, and the correlations between the incidence of an MB2 canal and age, gender, and tooth position.

Results: The incidence of 2-canaled MB roots was 71.

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Introduction: The purpose of this study was to evaluate the effects of endodontic irrigants on the push-out strength and hydration behavior of accelerated mineral trioxide aggregate (MTA) in its early setting phase.

Methods: In an in vitro perforation model, MTA with or without 10% CaCl(2) was condensed and allowed to initial set for 10 minutes. The samples were divided into four groups (n = 10) to be immersed into either 3.

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Introduction: The purpose of this study was to examine the lifespan of one nickel-titanium (NiTi) rotary file when used in reciprocating motion and to compare the time required for its preparation of a curved root canal using both reciprocating and continuous motion.

Methods: One hundred twenty curved canals from 60 extracted maxillary and mandibular molars were selected for measuring the mean number of uses. Each canal was prepared with reciprocating motion until the ProTaper F2 single file (Dentsply Maillefer, Ballaigues, Switzerland) reached the working length.

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Introduction: This study investigated changes in gene expressions related to mineralization when mineral trioxide aggregate (MTA) is applied in vitro to human dental pulp cells (HDPCs).

Methods: MTA in a Teflon tube (diameter 10 mm, height 2 mm) was applied to HDPCs. Empty tube-applied HDPCs were used as negative control.

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Objectives: The aim of this study was to investigate the cellular effects of newly developed calcium phosphate-based sealers (CAPSEAL I and II) using cultured human periodontal ligament cells (HPDLCs) compared with epoxy resin sealer (AH26; Dentsply, DeTrey, Konstanz, Germany), zinc oxide eugenol [ZOE] sealer (extended working time [EWT]; Kerr Corporation, Orange, CA), and CPC sealer (Sankin apatite sealer; Sankin-kogyo, Tokyo, Japan).

Methods: Cell viability by -(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazoliumbromide assay, cell attachment by scanning electron microscopy, osteoblastic differentiation and inflammatory mediators by reverse-transcriptase polymerase chain reaction, Western blotting, and alizarin red staining were evaluated.

Results: The cytotoxicities of CAPSEAL I and II were less than those of AH 26 and EWT after 1 and 14 days.

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Introduction: The purpose of this study was to evaluate the effect of different final irrigation regimens on the sealer penetration into dentinal tubules of curved root canals.

Methods: The mesiobuccal canals from 45 extracted maxillary and mandibular molars were instrumented with sodium hypochlorite (NaOCl) irrigation. The samples were divided into 3 groups according to the final irrigation used: group N (control), 3.

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Objective: The levels of 10 heavy metals (arsenic, bismuth, cadmium, chromium, copper, iron, lead, manganese, nickel, and zinc) in gray Portland cement (GPC), white Portland cement (WPC), gray MTA (GMTA), and white MTA (WMTA) were analyzed by inductively coupled plasma-atomic emission spectrometry (ICP-AES).

Study Design: One gram of each material was digested with 80 degrees C "aqua-regia" (7 mL of 60% HNO3 and 21 mL of 35% HCl), filtered, and analyzed by ICP-AES. The analysis was performed 6 times and the data were analyzed statistically.

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Objective: This study examined the effect of the manufacturing methods (ground, electropolished, and twisted) and the cross-sectional area (CSA) of nickel-titanium (NiTi) rotary instruments on their cyclic fatigue resistance.

Study Design: A total of 80 NiTi rotary instruments (ISO 25/.06 taper) from 4 brands (K3, ProFile, RaCe, and TF) were rotated in a simulated root canal with pecking motion until fracture.

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Chlorhexidine gluconate (CHX) has been widely used as a canal irrigant or an intracanal medicament on account of its antibacterial substantivity. This in vitro study aimed to determine if CHX attenuates the inflammatory activity of Enterococcus faecalis and its major virulence factor, lipoteichoic acid (LTA). An enzyme-linked immunosorbent assay showed that CHX-killed E.

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The purpose of this study was to evaluate the microleakage of accelerated mineral trioxide aggregate (MTA) and Portland cement by flow porometry analysis in an in vitro apexification model. Sixty-four single-rooted, extracted teeth were divided into 4 groups (group 1, MTA; group 2, MTA with accelerator; group 3, Portland cement; and group 4, Portland cement with accelerator). In an in vitro apexification model, MTA or Portland cement mixed with or without 10% CaCl2 was condensed to 2-mm thickness.

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