• The Journal of the Korean dental association
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• v.53 no.6
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• pp.418-426
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• 2015

The appropriate occlusion is one of the most important factors for the long-term success of implant and its restorations. The purpose of this review is to investigate and define occlusal considerations to reduce failure of implant prostheses. The physiological movement of implants is markedly lower than that of natural teeth and they also lack in occlusal sensitivity. Proper occlusal pattern may be assigned to compensate for the biological disadvantages and occlusal contacts must be formed where the cantilever effect is minimized. Moreover, the long-term success of implants after osseointegration can be assured by reducing early occlusal loading to avoid implant overloading and selecting appropriate occlusion material. Occlusal overload was brought by the number and location of occlusal contacts, which are under the clinician's control. The concept of implant occlusion is based on the concepts derived from traditional prosthetics. Moreover, there are few evidence on the concept or design of implant occlusion. Several occlusal design was recommended for implant prosthesis. Mutually protected occlusion, group function occlusion and bilateral balance occlusion was recommended for the specific types of implant restorations. This article reviews proper design of occlusion for implant restoration and offers occlusion strategy clinically.

• Journal of Korean Dental Science
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• v.3 no.2
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• pp.40-49
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• 2010

Dental clinicians often encounter cases wherein the patient's lost molar area was neglected and left untreated for an extended period of time, thereby causing the extrusion of opposite molars and occlusal disharmony as well as occlusion in the anterior teeth and consequently resulting in anterior displacement in the area. Clinicians normally carry out prosthetic treatment via occlusal plane lifting when such becomes absolutely necessary due to the lack of sufficient space needed for prosthetic therapy aimed at proper anterior and lateral induction. In this case report, we examined occlusal disharmony and VDO loss in a patient who had lost his molars and had not received prosthetic treatment for an extended period of time. We treated the maxillary area with dental implant prosthetics and Kennedy Class I RPD and the mandibular area with residual natural tooth-based implant placement and dental implant prosthetics. The patient reported treatment outcomes that were deemed satisfactory both functionally and aesthetically.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.4
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• pp.313-320
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• 2002

The purpose of the present study was to evaluate the marginal discrepancy and topography of artificial crown on teeth extracted due to severe periodontal disease. Twenty specimens were invested into metamethylacrylate resin and cutted into vertical slices along with the long axis of tooth. The selected marginal discrepancy between the outer edge of the crown and the finishing line of abutment was examined by stereo- microscope(Olympus, PM-VSP-3, Japan) at magnification of up to 10, and the topography of finishing margin on crown was observed by stereomicroscopeat magnification of up to $70{\times}$. The results were as follows. (1) The mean marginal discrepancy between extracted tooth and artificial crown were $50.82{\mu}m$. (2) There was a considerable difference in the microstructure of finishing margins among specimens. Microscopic Structure on finishing margin showed indefinite line, poor fit (open, underextended and overextended), distorted margin, and surface roughness. This study suggested that there could be necessary to consider the response of periodontium to the emergence profile of natural tooth and precision of marginal geometry while establishing treatment planning for the reconsruction of the artificial crown.

• The Journal of Korean Academy of Prosthodontics
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• v.16 no.1
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• pp.38-44
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• 1978

Color is an important factor in dental esthetics. Application of natural tooth color will not fail to produce pleasing results. But a standardized method of shade matching has not been adopted. If we are to overcome the color matching problem in dentistry, an understanding of the nature of color and light is essential. The purpose of this study was to compare the effects of different light sources and different background colors on the ability of observers to correctly match shades of artifical teeth. And observation was made to determine if the time spent in making a shade match was a factor in the correctness of the response. A test method was devised and 50 individuals made observations which were recorded and analyzed. $X^2$-test gave results indicating that the time factor had no effect on the response made. An analysis of variance showed the following effects significant at the five percent level; (1) light source (2) background color (3) subject. The following conclusions can be drawn from this study; (1) The time spent in making shade selection is not a factor in the correctness of the selections. (2) The light source used is an important factor in matching tooth shade; and there is no significant difference between the light sources in shade matching. (3) Under the conditions of this study, the greatest accuracy in shade matching was obtained on the brown background.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.4
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• pp.575-581
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• 1992

It is a very important procedure to establish the occlusal plane in the construction of complete denture. So many methods have been utilized to establish the occlusal plane in complete denture prosthodontics. However, no single method seems to fully accepted. This study was aimed to review the literature on establishing the occlusal plane in complete denture prosthodontics, to measure the distance from the lower border of the upper lip to the upper incisal edge and to investigate the correlation between the ala-tragus line and the occlusal plane. The results ware as follows ; 1. The average distance between the lower border of the upper lip and the upper incisal edge was $1.45{\pm}1.28mm$. 2. The distance between the lower border of the upper lip and the upper incisal edge had a tendency to decrease with age. 3. A angle of the ala-tragus line to the occlusal plane measured with Fox plane was $-1.41{\pm}2.33^{\circ}$. 4. The ala-tragus line to occlusal plane was nearly parallel, cosidering curve of spee in the upper natural teeth.

• Korean Journal of Plant Resources
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• v.32 no.1
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• pp.63-71
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• 2019

Two unrecorded alien plants, Melilotus officinalis (L.) Lam. and M. indicus (L.) All. (Leguminosae) were found in Korea. M. officinalis is native to Eurasia and widely distributed in agricultural regions throughout the world. M. indicus is native to Mediterranean and Southwestern Europe, and naturalized in temperate regions all over the world. These species are morphologically similar to M. suaveolens (Jeon-dong-ssa-ri). However, M. officinalis is distinguished from M. suaveolens by transverse nerved legumes, definite ovary stalks, and five to eight number of ovules in ovary. M. indicus is also distinguished from M. suaveolens by smaller size of flowers, broadly triangular calyx teeth, globose legumes, and minutely papillose seeds. The local name of M. officinalis and M. indicus were given as "Ju-reum-jeon-dong-ssa-ri" and "Jom-jeon-dong-ssa-ri" based on transverse nerved legumes and overall smaller size than M. suaveolens, respectively. The descriptions on morphological characters and photographs at the habitat of M. officinalis and M. indicus are provided.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.27 no.1
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• pp.51-61
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• 2018

Temporary restoration is one of the important processes in prosthodontic treatment, but some clinicians do not care about it. Most temporary restorations are literally used for a while, so most dentists like fast and cheap things. With the advent of dental CAD/CAM that can be made faster and easier with the changing age, the production of temporary restoration is also being digitized. It is good to be comfortable, but there are advantages and disadvantages. In this article, we are going to look at the 'analogue aesthetic anterior teeth temporary method' which seems to be the last generation.

• The Journal of Korean Academy of Prosthodontics
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• v.33 no.2
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• pp.281-299
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• 1995

The purpose of this study was to evaluate the degree of occlusal contact under the fixed implant prosthesis of partially edentulous patients which was hased on occlusal concept of implant prosthesis. From the patients who have free-standing implant supported prosthesis of unilateral partially edentulous area, occlusal and occlusal contact point of th enatural tooth side and implant side of light closure and heavy closure were analyzed by T-scan system throuht pre-and post-adjustment and the degree of occlusal contact was estimated by Shimstock. The following results were obtained : 1. The occlusal force of natural tooth side(NF) from mid-sagittal axis was relatively constant at light and heavy closure through pre-and post-adjustment, but the occlusal force of implant side(IF) was decreased significantly at light closure(P<0.01) and heavy closure(P<0.05) of post-adjustment. 2. Natural tooth side-implant side moment(MIMoment) fo occlusal force from mid-sagittal axis was significant(p<0.05) through pre-and post-adjustment and the deviation from mid-sagittal axis was increased at light closure of post-adjustment, but was decreased at heavy closure of post-adjustment. 3. Comparing the NF and IF, IF was greater at heavy closure of pre-adjustment, and NF was greater at light closure of post-adjustment, and the NF and IF was relatively equally distributed at light closure of pre-adjustment and at heavy closure of post-adjustment. 4. The number of occlusal contact point of natural tooth side(NC) was relatively constant through pre-and post-adjustment, but the number of occlusal contact point of implant side(IC) was significantly decreased(P<0.05) at light closure of post-adjustment, and was not significant but was lesser at heavy closure of post-adjustment. 5. Difference of the NC and IC was greater at light closure of post-adjustment, but it was less at heavy closure of post-adjustment, and therefore occlusal contact point of natural tooth side and implant side was relatively equally distributed at heavy closure of postadjustment. 6. When bilaterally distribution of occlusal force and occlusal contact point was established, degree of occlusal contact of implant suporoted prosthesis with opoosing teeth at light clousre was $34.13{\pm}21.69{\mu}m$.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.2
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• pp.145-152
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• 2012

Whenever pediatric dentists choose the preformed stainless steel crowns for restoration of primary molars, we usually prefer the crown forms that most fit to the abutment teeth. Despite some previous reports on significant ethnic difference in the size and shape of tooth crowns in primary dentition, only the imported products have been available to date, which might show some discrepancy with tooth anatomy of Korean. However, a domestic product of preformed stainless steel crown has been marketed recently that is expected to show more accurate fit to the primary tooth of Korean. To investigate the morphological characteristics of primary molars of Korean children, their mesiodistal and buccolingual diameters from the dental casts of 263 children in Pusan and Kyungsangnamdo province were measured by digital calipers. The measured data were compared with those of the three types of preformed stainless steel crowns(3M ESPE Stainless Steel Primary Molar Crown, Kids Crown, Sankin Anatom Primary Crown) by statistical processes with regression analysis. The results were as follows: 1. In every primary molar crown of three brands, the bucco-lingual width to mesio-distal width ratio (MD-BL ratio) showed higher values compared with those of natural teeth. 2. While the products of 3M ESPE and Shinhung showed similar features, those of Sankin showed some difference from both, and these difference was more marked in mandibular primary molars. 3. The nearer is the mesio-distal width of the crown to the average, the better was the adaptation of the preformed crown, and the reverse was true. 4. The teeth which revealed more discrepancy between preformed crown and natural tooth were upper and lower first primary molars.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.3
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• pp.202-210
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• 2014

Purpose: The aim of this study was to evaluate the stress concentration and distribution whether restoring the cavity or not while restoring with metal ceramic crown on tooth with abfraction lesion using finite element analysis. Materials and methods: Maxillary first premolar was selected and made a total of 10 finite element model. Model 1 was natural tooth; Model 2 was tooth with metal ceramic crown restoration which margin was positioned above 2 mm from CEJ; Model 3 was tooth with metal ceramic crown restoration which margin was positioned on CEJ; Model 4 was natural tooth which has abfraction lesion; Model 5 and 6 had abfraction lesion and the other condition was same as model 2 and 3, respectively; Model 7 was natural tooth which had abfraction lesion restored with composite resin; Model 8 and 9 was tooth with metal ceramic crown after restoring on abfraction lesion with composite resin; Model 10 was restored tooth on abfraction lesion with composite resin and metal ceramic crown restoration which margin is positioned on lower border of abfraction lesion. Load A and Load B was also designed. Von Mises value was evaluated on each point. Results: Under load A or load B, on tooth with abfraction lesion, stress was concentrated on the apex of lesion. Under load A or load B, on tooth that abfraction lesion was restored with composite resin, the stress value was reduced on the apex. Conclusion: In case of abfraction lesion was restored with composite resin, the stress was concentrated on the apical border of restored cavity regardless of marginal position. It was favorable to place crown margin on the enamel for restoring with metal ceramic crown.