PURPOSE: The aim of this pilot study was to investigate the effect of etched microgrooves on the hydrophilicity of Ti and osteoblast responses. MATERIAL AND METHODS: Microgrooves were applied on Ti to have 15 and 60 micrometer width, and 3.5 and 10 micrometer depth by photolithography, respectively. Further acid etching was applied to create Ti surfaces with etched microgrooves. Both smooth- and acid-etched Ti were used as the controls. The hydrophilicity of Ti was analyzed by determining contact angles. Cell proliferation and osteogenic activity of MC3T3 mouse preosteoblasts were analyzed by bromodeoxyuridine assay and alkaline phosphatase (ALP) activity test, respectively. One-way ANOVA, Pearson's correlation analysis and multiple regression analysis were used for statistics. RESULTS: Etched microgrooves significantly increased the hydrophilicity of Ti compared to the smooth Ti. 60 micrometer-wide etched microgrooves significantly enhanced cell proliferation, whereas the osteogenic activity showed statistically non-significant differences between groups. Result of the osteogenic activity significantly correlated with those of hydrophilicity and cell proliferation. Hydrophilicity was determined to be an influential factor on osteogenic activity. CONCLUSION: This study indicates that increase in hydrophilicity of Ti caused by etched microgrooves acts as an influential factor on osteogenic activity. However, statistically non-significant increase in the ALP activity suggests further investigation.
Alkaline Phosphatase ; Animals ; Bromodeoxyuridine ; Cell Proliferation ; Durapatite ; Hydrophobic and Hydrophilic Interactions ; Mice ; Osteoblasts ; Pilot Projects ; Titanium

All the faculties at the prosthodontic department in Kyung Hee University Dental Hospital at Gangdong, have been implementing the Top-Down concept of treatment approach since 2006 in which the outcomes of the last prosthetic treatment are predicted in advance during the treatment planning stage of patients with dental tissue defects. Based on the Top-Down concept, this report is also an example of how the final prosthetic treatment was performed in advance before going into implant surgery for the missing teeth. Among the various methods of connecting implant fixture and restoration, the cement-retained method is relatively simple to manufacture restoration without being constrained by the angle of the implants placed, but difficult to remove remaining subgingival excess cement completely, and to detach it being when necessary. In the report, SB-locking method will be introduced which enables an aesthetic implant restoration without either a screw hole or residual excess cement.

There has been a mistake, claimed and confirmed by all the authors of Vol 49(4), 2011, p. 333-340 issue, that first author should have been Hyun-Du Won instead of Ahran Pae.

The author names were mistakenly given as Richard Sungbok Lee in the original article. It should be corrected as Richard Leesungbok.

In the past, computer-aided design/computer-aided manufacturing (CAD/CAM) technology was the closed system that users had to use the components of only one manufacturer. At present, it has changed to the open system with the flexibility to select and use the components of various manufacturers' components according to their needs. Despite the development of dental materials and prostheses manufacturing methods, denture manufacturing has followed conventional manufacturing methods for nearly 100 years. However, studies on CAD/CAM fabricated denture have been recently carried out to overcome the disadvantages of conventional denture manufacturing. Some commercialized products using milling or 3D printing have already been applied clinically. This case report confirms the possibility of CAD/CAM dentures using 3D face scan and compared them to conventionally fabricated dentures.
Dental Materials ; Denture, Complete* ; Dentures ; Pliability ; Printing, Three-Dimensional ; Prostheses and Implants

PURPOSE: We aimed to investigate the gene expression of human gingival fibroblasts on microgroove surface using DNA microarray. MATERIALS AND METHODS: Microgrooves were applied on grade II titanium discs to have 0/0 µm (NE0, control group), 60/10 µm (E60/10, experimental group) of respective width/depth by photolithography. The entire surface of the microgrooved Ti substrata was further acid etched and used as the two experimental groups in this study. Human gingival fibroblasts were cultured in the experimental group and the control group, and total RNA was extracted. The oligonucleotide microarray was performed to confirm the changes of various gene expression levels between experimental group and control group. Changes of gene expression level were determined at the pathway level by mapping the expression results of DNA chips, using the KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis. RESULTS: Gene expression levels on E60/10 and NE0 were analyzed, there were 123 genes showing significant differences in expression more than 1.5 times on E60/10 microgrooved surface compared to NE0 surface, and 19 genes showing significant differences in expression more than 2 times. The KEGG pathway analysis confirmed the changes in gene expression levels under experimental conditions. Cell signaling, proliferation, and activity among the various gene expression results were identified. CONCLUSION: Microgrooved surfaces induce gene expression changes and related cell signaling. According to the results of this study, microgrooves can be used as the surface of various biomaterials which need to improve cell activity through gene expression changes and activation of cell signaling.
Biocompatible Materials ; DNA* ; Fibroblasts* ; Gene Expression* ; Humans* ; Oligonucleotide Array Sequence Analysis* ; RNA ; Titanium

PURPOSE: The aim of this investigation was to analyze the dimensions of clinical crowns and to classify the crown and the gingival type in the anterior teeth in Korean young adults. MATERIALS AND METHODS: Casts were obtained from 50 subjects ranging in age from 24 to 32. Measurements of length and width were made on the casts using a pair of digital calipers on the entire dentition. Crown thickness and papilla height were also measured and MDW/CL (mesiodistal width to clinical length) and CW/CL (cervical width to clinical length) ratios of the maxillary anterior teeth were calculated. The K-clustering method was used for CW/CL to classify the anterior tooth shape into three groups (tapered, ovoid, and square), and one-way analysis of variance and Duncan's post-hoc comparison were used to evaluate statistical significance between the groups. Pearson's correlation analysis was performed between tooth shape and papillary height (PH) to demonstrate the correlation between tooth shape and gingival morphological characteristics. RESULTS: The average length of the maxillary central incisors was 9.89 mm; the mesio-distal width was 8.54 mm; and the ratio of width/length was 0.86 in Korean young adults. The average bucco-palatal thickness of the central incisor was 3.14 mm at the incisal 1/3 aspect. Ovoid type was the most common tooth shape (48%), followed by square type (29%) and taper type (23%) in the central incisors of Korean young adults. Tooth shape and gingival type were correlated with each other. CONCLUSION: New reference data were established for tooth size in Korean young adults and the data show several patterns of tooth shape and gingival type. Clinicians should diagnose and treat based on these characteristics for better results in the Korean population.
Crowns* ; Dentition* ; Humans ; Incisor ; Methods ; Tooth ; Young Adult*

PURPOSE: The aim of this study was to study the effect of hydroxyapatite (HA) coating crystallinity on the proliferation and differentiation of human osteosarcoma cells. MATERIALS AND METHODS: Surface roughness of the titanium disks increased by anodizing treatment and then HA was coated using ion beam-assisted deposition (IBAD). HA coating was crystallized by heat-treated at different temperature (100degrees C, 300degrees C, 500degrees C, 800degrees C). According to the temperature, disks were divided into four groups (HA100, HA300, HA500, HA800). With the temperature, crystallinity of the HA coating was different. Anodized disks were used as control group. The physical properties of the disk surface were evaluated by surface roughness tests, XRD tests and SEM. The effect of the crystallinity of HA coating on HOS cells was studied in proliferation and differentiation. HOS cells were cultured on the disks and evaluated after 1, 3, 5, and 7 days. Growth and differentiation kinetics were subsequently investigated by evaluating cell proliferation and alkaline phosphatase activity. RESULTS: Regardless of the heat-treated temperature, there is no difference on the surface roughness. Crystallinity of the HA was appeared in the groups of HA500, HA800. HOS cells proliferation, ALP activity were higher in HA500 and HA800 group than HA100 and HA300. CONCLUSION: Within the results of this limited study, heat treatment at 500degrees C of HA coating produced by IBAD has shown greater effect on proliferation and differentiation of HOS cells. It is considered that further in vivo study will be necessary.
Alkaline Phosphatase ; Cell Proliferation ; Crystallins ; Crystallization ; Durapatite ; Hot Temperature ; Humans ; Kinetics ; Osteosarcoma ; Titanium

PURPOSE: The purpose of this study was to evaluate the effect of healing abutment height and measurement angle on implant stability when using Periotest and AnyCheck. MATERIALS AND METHODS: 60 implants were placed into artificial bone blocks. After implant insertion, 2, 3, 4 and 5 mm healing abutments were installed on 15 specimens, respectively. Insertion torque value, implant stability test, Periotest value were measured. Insertion torque value was controlled between 45 – 55 Ncm. AnyCheck was used for measuring implant stability test and Periotest M was used for measuring Periotest value. Implant stability test and Periotest value were measured at the angles of 0 and 30 degrees to the horizontal plane. Measured values were analyzed statistically. RESULTS: Insertion torque value had no significant difference among groups. When healing abutment height was higher, implant stability test and Periotest value showed lower stability. Also when measurement angle was decreased, implant stability test and Periotest value showed lower stability. CONCLUSION: When measuring stability of implants with percussion type devices, measured values should be evaluated considering height of healing abutments and measurement angle.
Percussion ; Torque

Generally dentures are manufactured by conventional method, however the frequency of fabricating denture using digital method is increasing due to the recent development of digital technology in dentistry. The digital method of manufacturing denture is classified into two systems; 3D scan of the impression to arrange the artificial teeth on the CAD (Computer-aided design) and 3D printing to produce the resin-based complete denture, or 3D scan of the model to design of the framework using CAD, resin pattern formation by 3D printing and casting of metal framework of complete denture or removable partial denture. In this case report, electronic surveying and design the metal framework of the dentures were performed using CAD program, and plastic resin patterns fabricated by 3D printing were casted for upper full denture and lower removable partial denture. During follow-up periods, dentures using digital method have provided satisfactory results esthetically and functionally.
Computer-Aided Design ; Dentistry ; Denture, Complete ; Denture, Partial, Removable ; Dentures* ; Follow-Up Studies ; Methods* ; Plastics ; Printing, Three-Dimensional ; Tooth, Artificial