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Position of maxillary central incisor and intercanine width in Korean adults.

Dong Hun YANG ; Jee Yun LEE ; Jae Sam BAN ; Gye Jeong OH ; Sang Won PARK

The Journal of Korean Academy of Prosthodontics.2013;51(3):147-152. doi:10.4047/jkap.2013.51.3.147

PURPOSE: The aim of this study was to propose the position of maxillary anterior teeth and intercanine width measurements based on the incisive papilla in accordance with the cephalic type and gender of dentate Korean adult with normal teeth alignment. MATERIALS AND METHODS: 42 students with Class I normal occlusion, without crowding or spacing, were selected from the Chonnam National University School of Dentistry. The lateral skull radiographs of the subjects were taken and were classified as different cephalic types, based on their PFH / AFH ratios. 42 casts of their maxilla were prepared and both the distance between the upper central incisors and the middle of the incisor papilla was measured with a vernier caliper (A) and the distance between the maxillary canine cusp tips (B) were measured. Statistical analysis was performed using SPSS version 15 and their significance was investigated. RESULTS: For dolichocephalic group, the mean values for A and B were 8.43 (SD: 0.61) and 36.73 (SD: 2.17), respectively. The mean value for A was 8.51 (SD: 1.27) for the mesocephalic group and 8.76 (SD 1.03) for the brachycephalic group. The mean value for B was 35.91 (SD: 1.86) for the mesocephalic group and 37.34 (SD: 2.23) for the brachycephalic group. For the male group, the mean A value was 8.86 (SD: 1.04) and the mean B value was 37.60 (SD: 0.24). For the female group, the mean A value was 8.41 (SD: 0.93) and the mean B value was 36.18 (SD: 2.01). The difference between male and female group in A values were not statistically significant (P>.05). The B values of the male subjects were greater than those of the female subjects and was statistically significant (P<.05). CONCLUSION: 42 students with normal dentition and occlusion in korea, the distance from the incisive papilla and the incisal edge of maxillary central incisors had no difference in cephalic type or gender. However, the distance between the cusp tip of both canines had significant difference in gender where the male showed higher values than the female, while having no difference in cephalic types.
Adult ; Crowding ; Dentistry ; Dentition ; Denture, Complete ; Female ; Humans ; Incisor ; Korea ; Male ; Maxilla ; Palate ; Skull ; Tooth

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The comparison of initial retentive force in different double crown systems.

Ho Beom KWON ; Yoon Ho ROH ; Seok Hyung LEE

The Journal of Korean Academy of Prosthodontics.2006;44(6):677-682.

STATEMENT OF PROBLEM: Various double crown systems have been used with removable partial dentures in the clinical field. Although retentive force between inner and outer crown are affected by several factors, differences between the retentive forces of different double crown system types are expected. PURPOSE: The purpose of this study was to evaluate the initial retentive force of outer crowns fabricated by the conventional casting technique in conus and hybrid double crowns. MATERIAL AND METHODS: Ten double crowns were fabricated. The groups were as follows. Group 1, double crowns of hybrid inner and outer crowns using the conventional casting method; Group 2, double crowns of conus inner and outer crowns using the conventional casting method. Tensile strengths of double crowns when the inner and outer crowns were separated on a universal testing machine were measured. These values of retentive force were then statistically analyzed using the Kruskal-Wallis test. RESULTS: Retentive force in group 2 was significantly higher than that in group 1 (p<.05). CONCLUSION: The initial retentive forces of double crowns were affected by the types of the double crown system.
Conus Snail ; Crowns* ; Denture, Partial, Removable ; Tensile Strength

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Marginal fit of the auro galvano crown system made using the electroforming technique.

Jae Ho YANG ; Tae Jin SONG ; Jung Suk HAN ; Jae Bong LEE ; Sun Hyung LEE

The Journal of Korean Academy of Prosthodontics.2004;42(6):679-683.

STATEMENT OF PROBLEM: There have been few studies about the marginal fit of Auro Galvano Crowns. PURPOSE: The purpose of this study was to compare the marginal fit of the anterior single restorations. MATERIAL AND METHODS: The in vitro marginal discrepancies of metal-ceramic, Auro Galvano Crown and coping were evaluated and compared. The Auro Gavano Crowns were made from one extracted maxillary central incisor prepared by milling machine. 30crowns per each system were fabricated. Measurements of a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Parametric statistical analysis was performed for the results. RESULTS: Mean marginal gap dimensions and standard deviations at the marginal opening for the anterior single crowns were 74+/-21micrometer for the control (metal-ceramic restoration), 45+/-11 micrometer for Auro Galvano Crown coping, and 51+/-9 micrometer for the Auro Galvano Crown. CONCLUSIONS: Auro Galvano Crown showed significantly smaller (P< .05) marginal gap than the control. Ceramic application did not significantly affected the marginal fit of Auro Galvano Crown. (P> .05)
Ceramics ; Crowns* ; Incisor

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Bone response of three different surface implants: histomorphometric and resonance frequency analysis in dogs.

Woo Seok SONG ; Yung Soo KIM ; Chang Whe KIM ; Kyung Soo JANG ; Young Jun LIM

The Journal of Korean Academy of Prosthodontics.2004;42(6):671-678.

STATEMENT OF PROBLEM: Reducing treatment time in implant dentistry is a matter of main concern. There are so many factors affecting the success rate of immediate or early loaded implant for the initial bone response. The especially microscopic properties of implant surfaces play a major role in the osseous healing of dental implant. PURPOSE: The aims of this study were to perform a histologic and histomorphometric comparison of the healing characteristics anodically roughened surface, HA coated surface and RBM surface implant, and to compare of ISQ values measured by Osstell(TM) for resonance frequency analysis in dogs mandible during 2 weeks. MATERIAL AND METHOD: Bone blocks from 2 dogs were caught after covered healing for 0 day(2h); Group I, 1 week; Group II and 2 weeks; Group III. One longitudinal section was obtained for each implant and stained with hematoxylin and eosin. Histomorphometric analysis was done with Kappa Imagebase system to calculate bone-to-implant contact and bone volumes inside the threads. ISQ values were measured in every time of surgery schedule. CONCLUSION: The experiment revealed that : 1. The percentages of bone-to-implant contact on the fixture in each group were not significantly different(P > 0.05). 2. The percentages of bone area inside the threads on the fixture in each group were not significantly different(P > 0.05). 3. The ISQ level showed clinical stability of each fixture during 2 weeks(all ISQ level >_71).
Animals ; Appointments and Schedules ; Dental Implants ; Dentistry ; Dogs* ; Eosine Yellowish-(YS) ; Hematoxylin ; Mandible

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The effect of abutment height on screw loosening in single implant-supported prostheses after dynamic cyclic loading.

Nam Gun KIM ; Yung Soo KIM ; Chang Whe KIM ; Kyung Soo JANG ; Young Jun LIM

The Journal of Korean Academy of Prosthodontics.2004;42(6):664-670.

STATEMENT OF PROBLEM: One of the common problems of dental implant prosthesis is the loosening of the screw that connects each component, and this problem is more common in single implant-supported prostheses with external connection. PURPOSE: The purpose of this study was to examine the changes of detorque values of abutment screws with external connection in different abutment heights. MATERIALS AND METHODS: After cyclic loading on three different abutment heights, detorque values were measured. Abutments were retained with titanium abutment screws tightened to 30 Ncm (30.5 kgmm) with digital torque gauge as recommended by the manufacturer. Replacing abutments, implants and titanium abutment screws with new ones at every measurement, initial detorque values were measured six times. In measuring detorque values after cyclic loading, Avana Cemented Abutments of 4.0 mm collar, 7.0 mm height (Osstem Co., Ltd., Seoul, Korea) were used with three different lengths of 5.0, 8.0, 11.0 mm. Shorter abutments were made by milling of 11.0 mm abutment to have the same force-exercised area of 4.5 mm diameter. Sine curve force (20N-320N, 14Hz) was applied, and detorque values were measured after cyclic loading of 2 million times by loading machine. Detorque values of initial and after-loading were measured by digital torque gauge. One-way ANOVA was employed to see if there was any influence from different abutment heights. RESULTS: The results were as follows : 1. The initial detorque value was 27.8+/-0.93 kgmm, and the ratio of the initial detorque value to the tightening torque was 0.91(27.8/30.5). 2. Measured detorque values after cyclic loading were declined as the height of the abutment increased, that was, 5.0 mm; 22.3+/-0.82 kgmm, 8.0 mm; 21.8+/-0.93 kgmm, and 11.0 mm; 21.3+/-0.94 kgmm. 3. One-way ANOVA showed no statistically significant differences among these (p> 0.05). 4. Noticeable mobility at the implant-abutment interface was not observed in any case after cyclic loading at all.
Dental Implants ; Prostheses and Implants* ; Seoul ; Titanium ; Torque

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Macro-shear bond strength and micro-shear bond strength of ceromer bonded to metal alloy and fiber reinforced composite.

Hyung Yoon PARK ; Lee Ra CHO ; Kyung Mo CHO ; Chan Jin PARK

The Journal of Korean Academy of Prosthodontics.2004;42(6):654-663.

STATEMENT OF PROBLEM: According to the fracture pattern in several reports, fractures most frequently occur in the interface between the ceromer and the substructure. PURPOSE: The aim of this in vitro study was to compare the macro shear bond strength and microshear bond strength of a ceromer bonded to a fiber reinforced composite (FRC) as well as metal alloys. MATERIAL AND METHODS: Ten of the following substructures, type II gold alloy, Co-Cr alloy, Ni-Cr alloy, and FRC (Vectris) substructures with a 12 mm in diameter, were imbedded in acrylic resin and ground with 400, and 1, 000-grit sandpaper. The metal primer and wetting agent were applied to the sandblasted bonding area of the metal specimens and the FRC specimens, respectively. The ceromer was placed onto a 6 mm diameter and 3 mm height mold in the macro-shear test and 1 mm diameter and 2 mm height mold in the micro-shear test, and then polymerized. The macro- and micro-shear bond strength were measured using a universal testing machine and a micro-shear tester, respectively. The macro- and micro-shear strength were analyzed with ANOVA and a post-hoc Scheffe adjustment (alpha= .05). The fracture surfaces of the crowns were then examined by scanning electron microscopy to determine the mode of failure. Chi-square test was used to identify the differences in the failure mode. RESULTS: The macro-shear strength and the micro-shear strength differed significantly with the types of substructure (P< .001). Although the ceromer/FRC group showed the highest macro and micro-shear strength, the micro-shear strength was not significantly different from that of the base metal alloy groups. The base metal alloy substructure groups showed the lowest mean macro-shear strength. However, the gold alloy substructure group exhibited the least micro-shear strength. The micro-shear strength was higher than the macro-shear strength excluding the gold alloy substructure group. Adhesive failure was most frequent type of fracture in the ceromer specimens bonded to the gold alloys. Cohesive failure at the ceromer layer was more common in the base metals and FRC substructures. CONCLUSION: The Vectris substructure had higher shear strength than the other substructures. Although the shear strength of the ceromer bonded to the base metals was lower than that of the gold alloy, the micro-shear strength of the base metals were superior to that of the gold alloy.
Adhesives ; Alloys* ; Crowns ; Fungi ; Gold Alloys ; Metals ; Microscopy, Electron, Scanning ; Nerve Fibers, Myelinated ; Polymers ; Shear Strength

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Fracture strengths of ceromer crowns supported on the various abutment core materials.

Young Oh KIM ; Chul Whoi KU ; Young Jun PARK ; Hong So YANG

The Journal of Korean Academy of Prosthodontics.2004;42(6):647-653.

STATEMENT OF PROBLEM: The effects of various core buildup materials which differs in the mechanical properties on the fracture strength of metal-free crowns is unknown. PURPOSE: This study was carried out to evaluate the fracture strengths of Artglass ceromer crowns supported by 3 different core materials in clinically simulated anterior tooth preparation. Material and methods. Ten crowns from each group were constructed to comparable dimensions on the various dies made by gold alloy, Ni-Cr alloy, and composite resin. The ten crowns were then cemented onto the dies and loaded until catastrophic failure took place. Fracture resistance to forces applied to the incisal edges of the anterior crowns supported by three types of dies was tested. RESULTS: The ceromer crowns on the composite resin dies fractured at significantly lower values(287.7 N) than the ceromer crowns on the metal dies(approximately 518.4 N). No significant difference was found between the fracture values of the ceromer crowns on the dies of gold alloy and Ni-Cr alloy. CONCLUSION: The failure loads of the ceromer crowns on the metal dies were almost the same and not affected by the differences of casting alloys. However, the fracture values of the ceromer crowns on the resin dies were significantly reduced by the relative weak properties of composite resin core material.
Alloys ; Crowns* ; Resin Cements ; Tooth Preparation

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The effort of various mixing methods on dynamic viscoelasticity of a temporary soft lining material; coe-comfort.

Hyun Ju RYU ; Hanna Eun Kyong BAE ; June Sung SHIM ; Seok Hyung LEE ; Hong Suk MOON ; Mun Kyu CHUNG

The Journal of Korean Academy of Prosthodontics.2004;42(6):641-646.

STATEMENT OF PROBLEM: Temporary soft relining materials are used in a diverse clinical situations such as tissue conditioner, relining material, functional impression by varying its viscoelasticity. However, reproduction of consistent viscoelasticity has been not possible. MATERIALS AND METHODS: Considering setting mechanism of this material, this study has measured the effect of varying amount of void in dynamic viscoelasticity of soft relining material, with three different mixing methods. In each methods 10 specimens were made and subjected to dynamic viscoelastic test which were measured at specific times over period of 72 hours. RESULTS: The analysis of the result shown that there was no statistically significant differences between different mixing methods. CONCLUSION: Different mixing methods had no effect over control of viscoelasticity of soft lining material. Further research is recommended for under similar oral environmental condition.
Reproduction

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Changes of abutment screw after repeated closing and opening.

Hee Jung KIM ; Chae Heon CHUNG ; Sang Ho OH ; Han Cheol CHOI

The Journal of Korean Academy of Prosthodontics.2004;42(6):628-640.

STATEMENT OF PROBLEM: Wear as a result of repeated closing/opening cycles may decrease the friction coefficient of screw head, threads, and other mating components and, consequently, resistance to opening gradually decreases. It may cause screw loosening, which is one of the most common failures in implant prosthesis. PURPOSE: The purpose of this study is to evaluate the changes on the head and thread surface of the abutment screws after repeated closing and opening through the examination of tested screws in SEM(scanning electron microscope). MATERIALS AND METHODS: Five species of abutments were selected (3i-three, Avana- two) respectively by two pieces. The implant fixtures were perpendicularly mounted in liquid unsaturated polyesther(Epovia, Cray Valley Inc.) with dental surveyor. Each abutment was secured to the implant fixture by each abutment screw with recommended torque value using a digital torque controller. The abutment screws were repeatedly tightened and removed 20 times with a digital controller. FESEM (field emission scanning electron microscope, Netherland, Phillips co., model:XL 30 SFEG) was used to observe changes of each part caused by repeatedly closing/opening expeiment. First, the Photomicrographs of pre-test screws provided by each manufacturer were taken. The changes of each screw were investigated after every fifth closing and opening experiment with FESEM. Scaning electron microscope photomicrographs of each screw were taken four times. RESULTS: As the number of closing and opening was increased, the wear or distortion of hexed or squared slot that contacted with the driver tip was more severely progressed. Wear or distortion of hexed slot was more severe than that of squared slot and it was more remarkable in the titanium screw than in the gold screw. All the tested screws showed that the width in the crest of their screw thread decreased gradually as the test was proceeded. CONCLUSIONS: Conclusively, we recommend the clinical use of gold screw, a periodic exchanges of abutment screws and avoiding repeated closing/opening unnecessarily. We also suggest a more careful manipulation of the abutment screw and screw-driver and using of abutment screw with an acute-angled slot design rather than an obtuse-angled one. Finally, it is suggested that the new slot design and the surface treatment for enduring wear or distortion should be devised.
Friction ; Head ; Prostheses and Implants ; Titanium ; Torque

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A tissue response to the titanium alloy (Ti-13Zr-6Nb) in vivo.

Chang Su KIM ; Seok Hyung LEE ; Sang Wan SHIN ; Kyu Won SUH ; Jae Jun RYU

The Journal of Korean Academy of Prosthodontics.2004;42(6):619-627.

STATEMENT OF PROBLEM: Mechanisms of tissue-implant interaction and the effect of the implant surface on the behavior of cells has not yet been clarified. PURPOSE: This study was performed to investigate the tissue reaction to the titanium alloy submerged into rat peritoneum in vivo. MATERIALS AND METHODS: Titanium alloys (titanium-13Zirconium-6Niobium) were inserted inside the peritoneal cavity of Sprague Dawley rats. After 3 months, the tissue formed around the inserted titanium alloys were examined with a light-microscope. Tissue reaction around the material was analyzed by confocal microscopy to evaluate their biocompatibility in a living body. RESULTS: In in vivo study, foreign body type multinucleated giant cells were found in the fibrous tissue formed as a reaction to the foreign material (4 in 20 cases), but the inflammatory reaction was very weak. After experiment, the contaminants of biomaterials was removed from living tissue. In confocal microscopy, we observed that the staining of vinculin and actin showed mixed appearance. In a few cases, we found that the staining of vinculin and beta-catenin showed the prominent appearance. CONCLUSION: We found that titanium-13Zirconium-6Niobium alloy was an excellent biomaterial.
Actins ; Alloys* ; Animals ; beta Catenin ; Biocompatible Materials ; Foreign Bodies ; Giant Cells ; Microscopy, Confocal ; Peritoneal Cavity ; Peritoneum ; Rats ; Rats, Sprague-Dawley ; Titanium* ; Vinculin

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