• Journal of Korean society of Dental Hygiene
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• v.24 no.2
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• pp.109-119
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• 2024

Objectives: This study aimed to confirm the correlation between oral frailty and health-related quality of life (HINT-8) among older adults in Korea. Methods: The data of 1,318 individuals aged ≥65 years who participated in the eighth Korean National Health and Nutrition Examination Survey (2019) were analyzed using complex sample statistical analysis. Results: Chewing discomfort was found to decrease the HINT-8 scores by 1.246, 1.324, and 1.089 times in the physical, social, and mental domains, respectively. Speech discomfort was found to decrease the HINT-8 scores by 1.275, 1.449, and 1.175 times in the physical, social, and mental domains, respectively. The HINT-8 scores of participants with ≤19 natural teeth were lower in the physical and social domains. Similarly, the HINT-8 scores of participants with brushing frequency of ≤2 were lower in the positive health domain. Non-use of oral hygiene products led to a reduction in the HINT-8 score in the social health domain. Conclusions: Oral frailty in older adults reduces the health-related quality of life. Thus, it is necessary to formulate policies to manage oral frailty in this population and develop specialized programs for the management of oral frailty.

• The Journal of Korean Academy of Prosthodontics
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• v.62 no.1
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• pp.64-71
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• 2024

The most critical aspect of full-arch prosthodontic treatment is evaluating whether the patient's vertical occlusal dimension is appropriate, and if necessary, restoring it through increasing vertical dimension. If the vertical occlusal dimension is too low, it can lead to reduced chewing efficiency, as well as not only aesthetic concerns but also potential issues like hyperactivity of muscles and posterior displacement of the mandible. This report is about the patient dissatisfied with pronunciation and aesthetics due to an inappropriate vertical occlusal dimension resulting from prior prosthetic interventions, underwent full-arch prosthodontic restoration treatment. Through the utilization of digital diagnostic apparatus, a comprehensive evaluation was undertaken for patient's vertical occlusal dimension, occlusal plane orientation, and the condition of prosthetic restorations. Through 3D facial scanning, the facial landmarks were discerned, and subsequently, the new occlusal plane was established. This provided the foundation for a digitally guided diagnostic wax-up. An elevation of 5 mm from the incisor was determined. Comprehensive dental rehabilitation was then executed for all remaining teeth, excluding the maxillary four incisors. The treatment protocol followed a systematic approach by initially creating implant-supported restorations on both sides of the dental arch to establish a stable occlusal contact. Subsequently, prosthetic restorations for the natural dentition were generated. Diagnostic and treatment planning were established through the utilization of facial scanning. This subsequently led to a reduction in treatment complexity and an expedited treatment timeline.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.3
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• pp.239-245
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• 2016

Purpose: The purpose of this study was to identify clinical complications in removable partial denture (RPD) with implant-supported surveyed prostheses, and to analyze the factors associated with the complications such as location of the implant, splinting adjacent prostheses, the type of retentive clasps, Kennedy classification, and opposing dentition. Materials and Methods: A retrospective clinical study was carried out for 11 patients (7 male, 4 female), mean age of 67.5, who received RPD with Implant-supported surveyed prostheses between 2000 and 2016. The mechanical complications of 11 RPDs and 37 supporting implant prostheses and the state of natural teeth and peripheral soft tissue were examined. Then the factors associated with the complications were analyzed. Results: The average of 3.4 implant-supported prostheses were used for each RPD. Complications found during the follow-up period of an average of 42.1 months were in order of dislodgement of temporary cement-retained prostheses, opposing tooth fracture/mobility, screw fracture/loosening, clasp loosening, veneer porcelain fracture, marginal bone resorption and mobility of implant, artificial tooth fracture. Complications occurred more frequently in anterior region compared to posterior region, non-splinted prostheses compared to splinted prostheses, surveyed prostheses applied by wrought wire clasp compared to other clasps, and natural dentition compared to other removable prostheses as opposing dentition. There were no significant differences in complications according to the Kennedy classification. Conclusion: All implant-assisted RPD functioned successfully throughout the follow-up. However, further clinical studies are necessary because the clinical evidences are still not enough to guarantee the satisfactory prognosis of implant-assisted RPD for long-term result.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.1
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• pp.30-37
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• 2009

Early enamel caries is commonly remineralized by the patient‘s improved oral hygiene or fluoridation, however the result is clinically unreliable. As an alternative, we tried to seal the lesions with low-viscosity light-curing resin. The aim of the present study was to search the proper methods of the adequate pretreatment prior to applying adhesive resin on natural proximal caries lesions. Thirty nine extracted deciduous molar teeth showing proximal early caries lesion were used for this study. They were divided into 5 groups : Group 1; only carefully cleaned with water, group 2; etched with 15% HCl for 15s, group 3; etched with 35% phosphoric acid for 15s, group 4; etched with 35% phosphoric acid for 30s, and group 5; cleaned with 0.5% NaOCl. Following results were obtained by evaluating with SEM and CLSM after applied with adhesive resin. 1. As a result of SEM evaluation, group 2 showed clearly removed surface layer, group 3,4 showed partially removed surface layer irregularly, group 5 showed slightly removed surface layer. 2. Group 2 showed the deepest infiltration depth, followed by group 4, group 3, group 5, group 1 and besides group 5, other groups showed significantly deep infiltration depth. (p < 0.01) In conclusion, the best methods of the adequate pretreatment on natural proximal caries lesion for deep infiltration of adhesive resin was to etch with 15% HCl for 15s.

• Journal of Dental Rehabilitation and Applied Science
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• v.33 no.4
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• pp.252-259
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• 2017

Purpose: The purpose of this study was to compare and analyze the wear of a prosthesis for 6 months after restoration with implant-supported fixed dental prosthesis made of either zirconia or gold. Materials and Methods: This study was conducted on patients requiring implant-supported fixed dental prostheses on first or second molar from January, 2015 to January, 2016. A total of 47 prostheses and antagonists were examined. Occlusal surface was recorded by impression of each prosthesis and antagonist 1 week and 6 months after prosthesis delivery. The digital files were created by impression scan. Occlusal shapes of 1 week and 6 months were compared and wear of prostheses and antagonists was analyzed. The Mann-Whitney test was used to analyzed the result data underwent normality test using SPSS (Version 23.0, IBM Corporation) Results: Mann-Whitney test revealed that there was no statistically significant difference in the median amount of mean vertical wear for 6 months in zirconia ($50.84{\mu}m$) and gold ($42.84{\mu}m$) prostheses (P > 0.05). When the opposing teeth were natural, the median amount of mean vertical wear of zirconia and gold prostheses was $47.72{\mu}m$ and $41.97{\mu}m$, respectively, and the median amount of mean vertical wear of enamel was $47.26{\mu}m$ and $44.59{\mu}m$, respectively. Statistical analysis showed no significant difference (P > 0.05). Conclusion: Despite the short study period and the small number of experimental groups, zirconia and gold showed no significant difference in wear during the first 6 months. Opposing natural enamel also showed no significant difference in the wear.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.4
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• pp.409-419
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• 2008

Statement of problem: At all times people have tried to fabricate tooth restorations using tooth colored materials. Recently, demands for esthetics, even in restorations requiring strength, has brought a revolution to dentistry and increased use of zirconia. The basic color of zirconia is white to ivory. The color can be partially adapted by veneering it with ceramic materials. However, it would be better if the substructure could already be adapted to the basic color shade of neighboring teeth. By adaptation to the basic shade, it can help to reduce the necessary layer thickness of the veneer ceramic to achieve the desired color. Purpose: The purpose of this study was to spectrophotometrically evaluate the influence of shading of zirconia core on the final shade of all-ceramic restorations using the CIE $L^{*}a^{*}b^{*}$ system. Material and methods: Core specimens (n = 20 per group) of Lava Frame Zirconia, KaVo Everest Zirconia, Digident CAD/CAM Zirconia were fabricated at 20 mm in diameter and 0.5 mm in thickness. Halves of each groups were shaded in A3 color. These core specimens were veneered with A3 porcelain of the recommended manufacturer at thickness of 0.5 mm. CIE $L^{*}a^{*}b^{*}$ coordinates were recorded for each specimen with a spectrophotometer (Model CM-2600d, Minolta, Japan) at 0.5 mm, 0.4 mm, 0.3 mm in thickness. Color differences were calculated using the equation ${\Delta}E^{*}=[({\Delta}L^{*})2+({\Delta}a^{*})2+({\Delta}b^{*})2]1/2$. Results: 1. In the case where porcelain layer has a thickness of 0.5 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, however Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 2. When the thickness of porcelain layer decreased from 0.5 mm to 0.4 mm, Lava Frame Zirconia and KaVo Everest group did not show clinically perceived color difference, on the other hand Digident CAD/CAM Zirconia group showed clinically perceived color difference according to shade allowed on core. 3. When the thickness of porcelain layer decreased from 0.5 mm to 0.3 mm, clinically perceived color differences were observed from all three groups. Conclusions: Ziroconia system, which is possible to allow shade on core, are thought to be much more favorable to reproduce natural shade compared to systems that is impossible to give shade. Therefore, clinicians ought to choose adequate system for certain clinical situation by considering above specific character.

• The Journal of Korean Academy of Prosthodontics
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• v.50 no.1
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• pp.61-66
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• 2012

Purpose: This study was to compare the cumulative survival rate (CSR) of Br${\aa}$nemark machined surface implants and TiUnite$^{TM}$ imlants and to analyze association between risk factors and the CSR of the implants. Materials and methods: A retrospective study design was used to collect long-term follow-up clinical data from dental records of 156 patients treated with 541 Br${\aa}$nemark machined and TiUnite$^{TM}$ implants at Korea University Guro hospital in South Korea from 1993 through 2008. Machined implant and TiUnite$^{TM}$ implant were compared by CSR. Exposure variables such as gender, systemic disease, location, implant length, diameter, prosthesis type, opposing occlusion type, date of implant placement, type of edentulous space, abutment type, existence of splinting with natural teeth, and existence of cantilever were collected. Life table analysis was undertaken to examine the CSR. Cox regression method was conducted to assess the association between potential risk factors and overall CSR (${\alpha}$=.05). Results: Patient ages ranged from 16 to 75 years old (mean age, 51 years old). Implants were more frequently placed in men than women (94 men versus 63 women). Since 1993, 264 Br${\aa}$nemark machined implants were inserted in 79 patients and since 2001, 277 TiUnite$^{TM}$ implants were inserted in 77 patients. A total survival rate of 86.07% was observed in Br${\aa}$nemark and Nobel Biocare TiUnite$^{TM}$ during 15 years. A survival rate of machined implant during 15 years was 82.89% and that of TiUnite$^{TM}$ implant during 5 years was 98.74%. The implant CSR revealed lower rates association with several risk factors such as, systemic disease, other accompanied surgery, implant location, and Kennedy classification. Conclusion: Clinical performance of Br${\aa}$nemark machined and TiUnite$^{TM}$ implant demonstrated a high level of predictability. In this study, TiUnite$^{TM}$ implant was more successful than machined implant. The implant CSR was associated with several risk factors.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.4
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• pp.731-752
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• 1995

This study was performed to research the changes of masticatory system subsequent to randomly increasing the vertical dimension. The subjects were twenty seven persons, twenty two men and five women, with a mean age of 24.3(age ranged from 22 to 26). The subjects had a complete or almost complete set of natural teeth and reported no subjected symptoms of pain or dysfunction in the masticatory system. The occlusal splint increased vertical dimension was made on semiadjustable articulator. The subjects were randomly divided to three groups according to the vertical dimension, at which the occlusal splint was made. Group I occlusal splints were made at 2mm form the occlusal vertical dimension, group II occlusal splints at 5mm, group III occlusal splints at 8mm. The occlusal splints were almost weared for 2 weeks except meal-time. Clinical examination, muscle activity, changes of free-way space, movement of mandible and articular condyle were recorded and analyzed by means of biopak system(Bioresearch Inc, Millwakee Wisconsin.) and radiograph. 1. In clinical examination, various symptoms were reported by all subjects immediately after the placement of occlusal splint. At the end of experiment, symptoms were lasted by 1 subject in Group I, 2 subjects in Group II, 6 subjects in Group III. At the other subjects, the most of symptoms were disappered within 2-4 days after the placement of occlusal splints. 2. The average free-way space before the startof experiment was 1.77mm in all twenty seven subjects. Immediately after the placement of occlusal splints, 0.67mm at Group I, 0.49mm at Group II, 0.41mm at Group III, At 2 weeks after the placement of occlusal splint 0.93mm, 0.79mm, 0.78mm each other, 1.94mm, 1.77mm, 2.3 mm at immediately after the removal of occlual splint. At 1 week after the removal of occlusal splint, free-way space was recovered to the pre-experimental state 3. In cephalometric radiograph, following either the placement or the removal of the occlusal splints, the movements of mandible in an antero-posterior direction were not statistically significant(p>0.05). 4. In transcranial radiograghs of TMJ, 1 week after the placement of occlusal splint the movement of most superior position on condyle in all group shoed antero-inferior position than before the experiment(p<0.001) and also showed antero-inferior position in mandibular postural rest position than in certric occlusion(p<0.001). Following either the placement or the removal of the splints, the amount of movement of most superior position on condyle was group III. group II and group I in order(p<0.001). 5. In anterior temporal and superficial masseter muscle, muscle activity at postural rest position decreased at 2 weeks after the placement of occlusal splint in group I and group II (p>0.05), but significantly increased in group III(p<0.001). At 1 week after the removal of the occdusal splint, muscle activity at postural rest position was recovered preconditional state 6. In anterior temporal and superficail masseter muscle, muscle activity at clenching in all group was significantly decreased after placement of the occlusal splint, slightly increased during experimental period and recovered to the original state at 1 week after removal of the occlusal splint. But was not statistically significat(p>0.05)s.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.99-107
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• 1997

The early life history and reproductive ecology of Siniperca scherzeri were studied to obtain fundamental information in aquaculture and reinforcement of natural population in Soyang Lake, Buk-myon, Chunchon-shi, Kangwon-do from June to October 1996. Symptric species with adult fishes (+1 ages) of Siniperca scherzeri were 11 species belonging to 6 families and 10 genera and those with Juveniles (2~3 months) were 5 species belonging to 4 families and 5 genera. The sex radio of this species were 1 (female, 85) : 1.24 (male, 105). Adult and juvenile of this species were predominantly piscivores. Bluegill, Lepomis macrochirus, Zacco platypus, common carp, Cyprinus carpio, unidentified fish and shrimp were important components of the food items. The spherical eggs were demersal and separative without a colorless transparent chorion and slightly yellowish yolk containing one large oil globule (0.5~0.7mm). The egg just after fertilization were measuring 1.72~2.05mm (n=30), and expanded to 2.27~2.58mm (n=30) in diameter after 30 min. Hatching occurred 130~155 hrs after fertilization at water temperature of $20{\sim}25^{\circ}C$ and newly hatched larvae measuring 5.5~7.1mm in total length. In the newly hatched larvae, numerous branched malanophores were distributed on the yolk and abdomen of caudal peduncle. In ten-day old larvae, the yolk was mostly absorbed and the head spines and the teeth were well developed. All fin rays were formed and total length of the larvae were reached 13.6~15.6mm at 20 days after hatching. In fifty-five day old larvae were similar in both body shape and color to adult. The juvenile stage at 4 months after hatching were attained 86.4~95.3mm (n=7) in total length and 8.77~14.78g (n=7) in body weight.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.2
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• pp.99-107
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• 2009

Statement of problem: Restoring and replacing teeth with fixed prostheses commonly used in dental practice. Because of improper oral hygiene care and inaccurate laboratory procedure, complications of fixed prostheses were found in the mouth of patients. Although many efforts have been continually made to obtain the data of long term prognosis of fixed prostheses, it was difficult to do it. Purpose: The purpose of this study was to evaluate the clinical status of fixed prostheses. Material and methods: In order to assess the clinical status of fixed prostheses, a total of 161 individuals(aged 17-85, 99 women and 62 men with 1596 unit of fixed prostheses, and 1169 abutments) who first visited the Department of Prosthodontics, Pusan National University Hospital, between April to September, in 2007 were examined. Results and conclusion: The results of this study were as follows: 1. Length of service of fixed prostheses was $8.6{\pm}0.6$ years(mean), 10.0 years(median). 2. Location of fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in posterior region and in mandible where the failure rate was high in combination(P<.05). 3. Longevity of fixed prostheses made of metal was longest(mean: $13.0{\pm}9.3$, median: 14.0), gold, precious ceramic, non-precious ceramic trailing behind(P<.05). 4. Number of units in fixed prostheses was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in Single-unit and the failure rate was high in over 3-unit(P<.05). 5. Condition of opposing dentition was found to have no statistically significant influence on longevity of fixed prostheses(P>.05). But, the success rate was high in natural dentition(P<.05). 6. Defective margin(28.2%), dental caries(23.0%), periodontal disease(19.3%), periapical disease(16.9%) were frequent complications. In 30.1% of the cases, abutment state after removing fixed prostheses was needed to be extracted.