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The effect of several root-end filling materials on MG63 osteoblast-like cells.

Jeong Ho LEE ; Won Jun SHON ; WooCheol LEE ; Seung Ho BAEK

Journal of Korean Academy of Conservative Dentistry.2010;35(3):222-228. doi:10.5395/JKACD.2010.35.3.222

The purpose of this study was to compare mineral trioxide aggregate (MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA), which is widely used as root-end filling material, with DiaRoot BioAggregate (DB; Innovative BioCaramix Inc, Vancouver, BC, Canada), newly developed product, by using MG63 osteoblast-like cells. MTA, DB, and Intermediate Restorative Material (IRM; Dentsply Caulk, Milford, DE, USA) were used for root-end filling material while tissue culture plastic was used for control group. Each material was mixed and, the mixtures were left to set for 24 hours. MG63 cells were seeded to each group and then they were cultured for attachment for 4 hours. Following the attachment of cells to the root-end filling material, early cellular response was observed. After another 12 hours'culture, the level of attachment between cells and material was observed and in order to identify the effect of each material to bone formation, transforming growth factor beta1 (TGFbeta1) and osteocalin (OC) were estimated by using enzyme-linked immunosorbent assay (ELISA), and the amount of alkaline phosphatase (ALP) was also measured. The data were analyzed using one-way ANOVA. As a result, only at OC and the number of cells which were attached to materials, there was no statistical difference between MTA and DB. At other items, there was statistically significant difference in all groups. Although DB has not shown exactly the same cellular response like that of MTA, the number of attached cells shows that biocompatibility of the material and OC indicates bone formation rate. Therefore, if DB is used for root end filling material, it is expected to lead to similar results to MTA.
Alkaline Phosphatase ; Aluminum Compounds ; Calcium Compounds ; Calcium Hydroxide ; Drug Combinations ; Enzyme-Linked Immunosorbent Assay ; Glutamates ; Guanine ; Hydroxyapatites ; Osteogenesis ; Oxides ; Plastics ; Polymethyl Methacrylate ; Seeds ; Silicates ; Transforming Growth Factor beta1 ; Pemetrexed

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The effect of the removal of chondroitin sulfate on bond strength of dentin adhesives and collagen architecture.

Jong Ryul KIM ; Sang Jin PARK ; Gi Woon CHOI ; Kyoung Kyu CHOI

Journal of Korean Academy of Conservative Dentistry.2010;35(3):211-221. doi:10.5395/JKACD.2010.35.3.211

Proteoglycan is highly hydrophilic and negatively charged which enable them attract the water. The objective of study was to investigate the effects of Proteoglycan on microtensile bond strength of dentin adhesives and on architecture of dentin collagen matrix of acid etched dentin by removing the chondroitin sulphate attached on Proteoglycan. A flat dentin surface in mid-coronal portion of tooth was prepared. After acid etching, half of the specimens were immersed in 0.1 U/mL chondroitinase ABC (C-ABC) for 48 h at 37degrees C, while the other half were stored in distilled water. Specimens were bonded with the dentin adhesive using three different bonding techniques (wet, dry and re-wet) followed by microtensile bond strength test. SEM examination was done with debonded specimen, resin-dentin interface and acid-etched dentin surface with/without C-ABC treatment. For the subgroups using wet-bonding or dry-bonding technique, microtensile bond strength showed no significant difference after C-ABC treatment (p > 0.05). Nevertheless, the subgroup using rewetting technique after air dry in the Single Bond 2 group demonstrated a significant decrease of microtensile bond strength after C-ABC treatment. Collagen architecture is loosely packed and some fibrils are aggregated together and relatively collapsed compared with normal acid-etched wet dentin after C-ABC treatment. Further studies are necessary for the contribution to the collagen architecture of noncollagenous protein under the various clinical situations and several dentin conditioners and are also needed about long-term effect on bond strength of dentin adhesive.
Adhesives ; Bisphenol A-Glycidyl Methacrylate ; Chondroitin ; Chondroitin ABC Lyase ; Chondroitin Sulfates ; Collagen ; Dentin ; Proteoglycans ; Tooth ; Water

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A clinical evaluation of safety of an office bleaching gel containing 30% hydrogen peroxide.

Sin Young KIM ; Je Uk PARK ; Chang Hyen KIM ; Sung Eun YANG

Journal of Korean Academy of Conservative Dentistry.2010;35(3):198-210. doi:10.5395/JKACD.2010.35.3.198

This study evaluated the safety of an office bleaching gel (RemeWhite, Remedent Inc., Deurle, Belgium) containing 30% hydrogen peroxide. 37 volunteers were recieved office bleaching with the RemeWhite for 3 times at one visit, total 2 visits. As control group, the same gel in which hydrogen peroxide was not included was applied to 34 volunteers with the same protocol. There was no difference between experimental group and control group using electric pulp test. In the result of gingival inflammation index and tooth sensitivity test, there was mild pain response in experimental group but it disappeared as time went by. Therefore, safety of the office bleaching gel containing 30% hydrogen peroxide was confirmed.
Hydrogen ; Hydrogen Peroxide ; Inflammation ; Tooth

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Evaluation of radiopacity and discriminability of various fiber reinforced composite posts.

Eun Hye LEE ; Hang Moon CHOI ; Se Hee PARK ; Jin Woo KIM ; Kyung Mo CHO

Journal of Korean Academy of Conservative Dentistry.2010;35(3):188-197. doi:10.5395/JKACD.2010.35.3.188

The purpose of this study was to compare radiopacity and radiographic discriminability of various FRC-Posts. Six FRC-Posts were investigated ; 1) FRC Postec Plus (Ivoclar Vivadent AG, Schaan, Liechtenstein), 2) Snowlight (Carbotech, Lewis center, OH, USA), 3) Dentin Post (Komet Brasseler, Lamgo, Germany), 4) Rely-X Fiber Post (3M ESPE, St.paul, MN, USA), 5) D.T.-Light Post (BISCO, Schaumburg, IL,USA), 6) Luxapost (DMG, Hamburg, Germany) The radiographs of each post with a reference 1 mm / 2 mm aluminum step-wedge was taken using digital sensor. The optical density were calculated by gray value of 10 x 10 pixel and compared in mm Al equivalent at five points. Six maxillary incisors of similar radiopacity were used. Radiographs of posts in Mx. incisors of lingual side of dry mandible were taken. We showed radiographs and asked the questionnaire to 3 radiologists, 3 endodontists, 3 general practitioners. The questionnaire was comprised of choices of the highest, lowest radiopaque individual post and the choices of best discriminable post at apical, coronal area. The following results were obtained. 1. Each post system showed various radiopacity. 2. There was change of discriminability between each post and simulated specimens regardless of examiner. Although each post showed various radiopacity, the difference of radiopacity did not affect on discriminability.
Acrylic Resins ; Aluminum ; Composite Resins ; Dentin ; General Practitioners ; Humans ; Incisor ; Mandible ; Polyurethanes ; Resin Cements ; Surveys and Questionnaires

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A new method to measure the linear polymerization shrinkage of composites using a particle tracking method with computer vision.

In Bog LEE ; Sun Hong MIN ; Deog Gyu SEO ; Sun Young KIM ; Youngchul KWON

Journal of Korean Academy of Conservative Dentistry.2010;35(3):180-187. doi:10.5395/JKACD.2010.35.3.180

Since the introduction of restorative dental composites, their physical properties have been significantly improved. However, polymerization shrinkage is still a major drawback. Many efforts have been made to develop a low shrinking composite, and silorane-based composites have recently been introduced into the market. In addition, many different methods have been developed to measure the polymerization shrinkage. In this study, we developed a new method to measure the linear polymerization shrinkage of composites without direct contact to a specimen using a particle tracking method with computer vision. The shrinkage kinetics of a commercial silorane-based composite (P90) and two conventional methacrylate-based composites (Z250 and Z350) were investigated and compared. The results were as follows: 1. The linear shrinkage of composites was 0.33-1.41%. Shrinkage was lowest for the silorane-based (P90) composite, and highest for the flowable Z350 composite. 2. The new instrument was able to measure the true linear shrinkage of composites in real time without sensitivity to the specimen preparation and geometry.
Kinetics ; Polymerization ; Polymers ; Silorane Resins ; Track and Field ; Vision, Ocular

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Effect of surface treatments of fiber posts on bond strength to composite resin cores.

Hye Jo KEUM ; Hyun Mi YOO

Journal of Korean Academy of Conservative Dentistry.2010;35(3):173-179. doi:10.5395/JKACD.2010.35.3.173

The purpose of the present study was to compare the influence of post-surface treatment with silane, hydrogen peroxide, hydrofluoric acid or sandblasting and to investigate the effect of silane in combination of the other treatments on the microtensile bond strength between fiber posts and composite resins for core build-up. Thirty-two glass-fiber posts (FRC Postec Plus, Ivoclar Vivadent, Schaan, Liechtenstein) were divided into eight groups according to the different surface pretreatments performed: silane application (S); immersion in 28% hydrogen peroxide (HP); immersion in hydrogen peroxide followed by application of silane (HP-S); immersion in 4% hydrofluoric acid gel (HF); immersion in hydrofluoric acid gel followed by application of silane (HF-S); sandblasting with aluminum oxide particles (SB); sandblasting followed by application of silane (SB-S). In control group, no surface treatment was performed. The composite resin (Tetric Flow, Ivoclar Vivadent, Schaan, Liechtenstein) was applied onto the posts to produce the composite cylinder specimen. It was sectioned into sticks to measure the microtensile bond strength. The data was analyzed with one-way ANOVA and LSD test for post hoc comparison (p < 0.05). Post pretreatment with sandblasting enhanced the interfacial strength between the fiber posts and core materials. Moreover, sand-blasting followed by application of silane appears to be the most effective method that can improve the clinical performance of glass fiber posts.
Acrylic Resins ; Aluminum Oxide ; Composite Resins ; Glass ; Hydrofluoric Acid ; Hydrogen Peroxide ; Immersion ; Lysergic Acid Diethylamide ; Polyurethanes ; Waxes

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Influence of rebonding procedures on microleakage of composite resin restorations.

Mi Ae LEE ; Duck Kyu SEO ; Ho Hyun SON ; Byeong Hoon CHO

Journal of Korean Academy of Conservative Dentistry.2010;35(3):164-172. doi:10.5395/JKACD.2010.35.3.164

During a composite resin restoration, an anticipating contraction gap is usually tried to seal with low-viscosity resin after successive polishing, etching, rinsing and drying steps, which as a whole is called rebonding procedure. However, the gap might already have been filled with water or debris before applying the sealing resin. We hypothesized that microleakage would decrease if the rebonding agent was applied before the polishing step, i.e., immediately after curing composite resin. On the buccal and lingual surfaces of 35 extracted human molar teeth, class V cavities were prepared withthe occlusal margin in enamel and the gingival margin in dentin. They were restored with a hybrid composite resin Z250 (3M ESPE, USA) using an adhesive AdperTM Single Bond 2 (3M ESPE). As rebonding agents, BisCover LV (Bisco, USA), ScotchBond Multi-Purpose adhesive (3M ESPE) and an experimental adhesive were applied on the restoration margins before polishing step or after successive polishing and etching steps. The infiltration depth of 2% methylene blue into the margin was measured using an optical stereomicroscope. The correlation between viscosity of rebonding agents and mciroleakage was also evaluated. There were no statistically significant differences in the microleakage within the rebonding procedures, within the rebonding agents, and within the margins. However, when the restorations were not rebonded, the microleakage at gingival margin was significantly higher than those groups rebonded with 3 agents (p < 0.05). The difference was not observed at the occlusal margin. No significant correlation was found between viscosity of rebonding agents and microleakage, except very weak correlation in case of rebonding after polishing and etching at gingival margin (r = -0.326, p = 0.041).
Acrylates ; Adhesives ; Bisphenol A-Glycidyl Methacrylate ; Chimera ; Contracts ; Dental Enamel ; Dentin ; Humans ; Methylene Blue ; Molar ; Resin Cements ; Tooth ; Viscosity

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Gene expression profiling in human dental pulp cells treated with mineral trioxide aggregate.

Yong Beom KIM ; Won Jun SHON ; WooCheol LEE ; Kee Yeon KUM ; Seung Ho BAEK ; Kwang Shik BAE

Journal of Korean Academy of Conservative Dentistry.2010;35(3):152-163. doi:10.5395/JKACD.2010.35.3.152

This study investigated the changes in gene expression when mineral trioxide aggregate (MTA) was applied in vitro to human dental pulp cells (HDPCs). MTA in a teflon tube (diameter 10 mm, height 2 mm) was applied to HDPCs. Empty tube-applied HDPCs were used as negative control. For microarray analysis, total RNA was extracted at 6, 24, and 72 hrs after MTA application. The results were confirmed selectively by performing reverse transcriptase polymerase chain reaction for genes that showed changes of more than two-fold or less than half. Of the 24,546 genes, 109 genes were up-regulated greater than two-fold (e.g., FOSB, THBS1, BHLHB2, EDN1, IL11, FN1, COL10A1, and TUFT1) and 69 genes were down-regulated below 50% (e.g., SMAD6 and DCN). These results suggest that MTA, rather than being a bio-inert material, may have potential to affect the proliferation and differentiation of pulp cells in various ways.
Aluminum Compounds ; Calcium Compounds ; Dental Pulp ; Dental Pulp Capping ; Drug Combinations ; Gene Expression ; Gene Expression Profiling ; Glutamates ; Guanine ; Humans ; Interleukin-11 ; Microarray Analysis ; Oxides ; Polytetrafluoroethylene ; Reverse Transcriptase Polymerase Chain Reaction ; RNA ; Silicates ; Pemetrexed

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Mineral trioxied aggregate and its substitutes.

Yong Bum CHO

Journal of Korean Academy of Conservative Dentistry.2010;35(3):149-151. doi:10.5395/JKACD.2010.35.3.149

Since its introduction in 1993, Mineral Trioxide Aggregate (MTA) has been shown to be superior to others in sealing, biocompatibility, and many other aspects of clinical endodontics. MTA is primarily Portland cement with bismuth oxide as a radiopacitifier. Although some studies suggested that the reasonable-priced Portland cement could be used instead of MTA, but MTAs are different from Portland cement in its composition, especially in heavy metal contents. Therefore, clinicians should be meticulous adapting the Portland cement as a MTA substitute.
Aluminum Compounds ; Bismuth ; Calcium Compounds ; Drug Combinations ; Endodontics ; Glutamates ; Guanine ; Oxides ; Silicates ; Pemetrexed

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Gene expression of human coronary artery endothelial cells in response to Porphyromonas endodontalis invasion.

Hee Joung KONG ; Kyoung Kyu CHOI ; Sang Hyuk PARK ; Jin Yong LEE ; Gi Woon CHOI

Journal of Korean Academy of Conservative Dentistry.2009;34(6):537-550. doi:10.5395/JKACD.2009.34.6.537

During the last two decades, there has been an increasing interest in the impact of oral health on atherosclerosis and subsequent cardiovascular disease (CVD). To date, some periodontal pathogens including Porphyromonas gingivalis (P. gingivalis) have been reported to be relevant to CVD. Porphyromonas endodontalis (P. endodontalis), which shares approximately 87% sequence homology with P. gingivalis, is mostly found within infected root canals. However, recent studies reveal that this pathogen also resides in the dental plaque or periodontal pocket in patients with periodontitis. It has been shown that P. endodontalis invades human coronary artery endothelial cells (HCAEC) and coronary artery smooth muscle cells (CASMC). To evaluate whether P. endodontalis can participate in the progression of atherosclerosis and CVD, we examined the changes in transcriptional gene expression profiles of HCAEC responding to invasion by P. endodontalis in this study. The following results were obtained. 1. Porphyromonas endodontalis was invasive of HCAEC. 2. According to the microarray analysis, there were 625 genes upregulated more than two-folds, while there were 154 genes downregulated by half. 3. Upregulated genes were relevant to inflammatory cytokines, apoptosis, coagulation and immune response. Enhanced expression of MMP-1 was also noticeable. 4. The transcription profiles of the 10 selected genes examined by real-time PCR agreed well with those observed in the microarray analysis. Thus, these results show that P. endodontalis presents the potential to trigger and augment atherosclerosis leading to CVD.
Apoptosis ; Atherosclerosis ; Cardiovascular Diseases ; Coronary Vessels ; Cytokines ; Dental Plaque ; Dental Pulp Cavity ; Endothelial Cells ; Gene Expression ; Humans ; Microarray Analysis ; Myocytes, Smooth Muscle ; Oral Health ; Periodontal Pocket ; Periodontitis ; Porphyromonas ; Porphyromonas endodontalis ; Porphyromonas gingivalis ; Real-Time Polymerase Chain Reaction ; Sequence Homology ; Transcriptome

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