• Journal of the Korean Academy of Esthetic Dentistry
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• v.29 no.1
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• pp.25-34
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• 2020

In recent years, as a burden on tooth preparationduring the processing the laminate veneer treatments to enhance aesthetics, the interests and demands for non-prep laminate veneers are increasing which do not require teeth preparation. Although there are clear limitationsbecause the restorations are fabricated without tooth preparation, there is a clear advantage of non-invasivehealthy teeth. When manufacturing a non-prep laminate veneer, an effective design should be selected according to the aesthetic requirements and intraoral condition because the margin of restorationsshould be determined on the natural tooth surface that isnot prepared. In this article, I would like to presentthe three different designsaccording to the range which teeth are covered, and the advantages and disadvantages of them. Non-prep laminate veneer introduced in this article was fabricated using Lithium disilicate press ingot.

• Proceedings of the KACD Conference
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• 2008.05a
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• pp.177-183
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• 2008

It was reported that esthetic composite resin restoration reinforces the strength of remaining tooth structure with preserving the natural tooth structure. However, it is unknown how much the strength would be recovered. The purpose of this study was to compare the fracture resistance of three types of undermined cavity filled with composite resin with that of non-cavitated natural tooth. Forty sound upper molars were allocated randomly into four groups of 10 teeth. After flattening occlusal enamel. undermined cavities were prepared in thirty teeth to make three types of specimens with various thickness of occlusal structure (Group $1{\sim}3$). All the cavity have the 5 mm width mesio-distally and 7 mm depth bucco-lingually. Another natural 10 teeth (Group 4) were used as a control group. Teeth in group 1 have remaining occlusal structure about 1 mm thickness, which was composed of mainly enamel and small amount of dentin. In Group 2, remained thickness was about 1.5 mm, including 0.5 mm thickness dentin. In Group 3, thickness was about 2.0 mm, including 1 mm thickness dentin. Every effort was made to keep the remaining dentin thickness about 0.5 mm from the pulp space in cavitated groups. All the thickness was evaluated with radiographic Length Analyzer program. After acid etching with 37% phosphoric acid, one-bottle adhesive (Single $Bond^{TM}$, 3M/ESPE, USA) was applied following the manufacturer's recommendation and cavities were incrementally filled with hybrid composite resin (Filtek $Z-250^{TM}$, 3M/ESPE, USA). Teeth were stored in distilled water for one day at room temperature, after then, they were finished and polished with Sof-Lex system. All specimens were embedded in acrylic resin and static load was applied to the specimens with a 3 mm diameter stainless steel rod in an Universal testing machine and cross-head speed was 1 mm/min. Maximum load in case of fracture was recorded for each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA) and a Tukey test at the 95% confidence level. The results were as follows: 1. Fracture resistance of the undermined cavity filled with composite resin was about 75% of the natural tooth. 2. No significant difference on fracture loads of composite resin restoration was found among the three types of cavitated groups. Within the limits of this study, it can be concluded the fracture resistance of the undermined cavity filled with composite resin was lower than that of natural teeth, however remaining tooth structure may be supported and saved by the reinforcement with adhesive restoration, even of that portion consists of mainly enamel and a little dentin structure.

• Restorative Dentistry and Endodontics
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• v.33 no.3
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• pp.177-183
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• 2008

It was reported that esthetic composite resin restoration reinforces the strength of remaining tooth structure with preserving the natural tooth structure. However, it is unknown how much the strength would be recovered. The purpose of this study was to compare the fracture resistance of three types of undermined cavity filled with composite resin with that of non-cavitated natural tooth. Forty sound upper molars were allocated randomly into four groups of 10 teeth. After flattening occlusal enamel, undermined cavities were prepared in thirty teeth to make three types of specimens with various thickness of occlusal structure (Group $1{\sim}3$). All the cavity have the 5 mm width mesiodistally and 7 mm depth bucco-lingually. Another natural 10 teeth (Group 4) were used as a control group. Teeth in group 1 have remaining occlusal structure about 1 mm thickness, which was composed of mainly enamel and small amount of dentin. In Group 2, remained thickness was about 1.5 mm, including 0.5 mm thickness dentin. In Group 3, thickness was about 2.0 mm, including 1 mm thickness dentin. Every effort was made to keep the remaining dentin thickness about 0.5 mm from the pulp space in cavitated groups. All the thickness was evaluated with radiographic Length Analyzer program. After acid etching with 37% phosphoric acid, one-bottle adhesive (Single $Bond^{TM}$, 3M/ESPE, USA) was applied following the manufacturer's recommendation and cavities were incrementally filled with hybrid composite resin (Filtek $Z-250^{TM}$, 3M/ESPE, USA). Teeth were stored in distilled water for one day at room temperature, after then, they were finished and polished with Sof-Lex system. All specimens were embedded in acrylic resin and static load was applied to the specimens with a 3 mm diameter stainless steel rod in an Universal testing machine and cross-head speed was 1 mm/min. Maximum load in case of fracture was recorded for each specimen. The data were statistically analyzed using one-way analysis of variance (ANOVA) and a Tukey test at the 95% confidence level. The results were as follows: 1. Fracture resistance of the undermined cavity filled with composite resin was about 75% of the natural tooth. 2. No significant difference in fracture loads of composite resin restoration was found among the three types of cavitated groups. Within the limits of this study, it can be concluded the fracture resistance of the undermined cavity filled with composite resin was lower than that of natural teeth, however remaining tooth structure may be supported and saved by the reinforcement with adhesive restoration, even if that portion consists of mainly enamel and a little dentin structure.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.7 no.1
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• pp.28-31
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• 1998

It is difficult to make an artificial central incisor similar to natural tooth. All ceramic porcelain of this patient is not esthetic, and there is gingival recession due to ill-fitted margin. She has class II division 1 occlusion, so upper central incisors is labioversed. Upper light central incisor is well-characterized but the yellowish brown color of dentin is appeared on the incisal third portion of the central incisor. At 1st trial, the shape and characterization of restoration is good but shade is little dark. At 2nd trial, the shape is better but patient complained on black triangle of mid interdental space, so mesiocervical portion of restoration is overcontoured to compromise the black triangle. Completed metal ceramic crown is in harmony with the adjacent central incisor in aspect of shape, shade, and characterization.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.803-806
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• 2002

This paper estimated the stability of centrifuge as its rotating speed compared with the natural frequency of cylinder and screw by finite element analysis. It shows that the one of exciting causes is the tooth passing frequency of input and output parts by the periodic characteristics of transmission error due to an planetary gear having three stages. Also, it proposed the critical speed of cylinder and screw by the Campbell diagram.

• The Journal of the Korean dental association
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• v.22 no.10 s.185
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• pp.869-877
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• 1984

An objective examination of 123 subjects aged from 19 to 23 was made from a clinical standpoints to determine the natural occurrence in anterior tooth contact in centric occlusion, and tooth contact in protrusive occlusion, left and right lateral excursions, and temporomandibular dysfunction. 1. In centric occlusion, maxillary 6 anterior contact type was frequently observe (30.08%) compared with other types of contact (incisor contact: 19.47%, no contact: 17.70%, canine and incisor contact: 15.04%, canines contact: 12.39%, unilateral canine contact: 5.31%) (P<0.01) 2. In protrusive position (edge to edge bite), maxillary central incisors contact was predominant (86.7%). (P<0.01) 3. In lateral excursion, there was not any significant difference between canine guided occlusion (47.79%) and group function occlusion (total 51.32%, AG:9.29%, PG:13.27%, G:28.76%). 4. Temporomandibular joint dysfunction was observed in 12.4% of 123 subjects.

• Restorative Dentistry and Endodontics
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• v.38 no.2
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• pp.85-89
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• 2013

When a patient with a fractured anterior tooth visits the clinic, clinician has to restore the tooth esthetically and quickly. For esthetic resin restoration, clinician can use 'Natural Layering technique' and an index for palatal wall may be needed. In this case report, we introduce pre-restoration index technique on a Class IV defect, in which a temporary filling material is used for easy restoration. Chair-side index fabrication for Class IV restoration is convenient and makes a single-visit treatment possible.

• The Journal of Korean Academy of Prosthodontics
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• v.30 no.4
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• pp.565-573
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• 1992

This clinical study was to analyze occlusal contacts in maximum intercuspation on distal extension partial denture and to compare tooth contact state between the denture teeth and abutment teeth by time mode and force mode using the T-scan system. The subjects ware twenty-one adult patients with upper natural teeth and lower distal extension partial denture. Conclusion : 1. The patient with simultaneous occlusal contacts both denture tooth and abutment and bilaterally in Kennedy Class I cases was one-sixth, but there was no one with symmetric occlusal and equal force among bilateral denture teeth and abutments. 2. The five-fifteenth of Kennedy Class I case patients resulted in simultaeous occlusal contacts bet-ween denture teeth and abutments but no one has the symmetric occlusal contacts and unifarm force between denture teeth and abutment teeth.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.27 no.1
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• pp.18-23
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• 2018

With the increasing demand for esthetics and minimum intervention concept, people want to restore the fractured tooth with direct composite restoration. But even now, many dentists hesitate to do the direct resin restoration in the anterior region and shift the responsibility to dental technicians. This article describes each steps in restoring Class IV cavity. To obtain an esthetic result in anterior restoration, layering technique is mandatory and clinical tips suggested in this article would be useful.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.2
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• pp.242-254
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• 2000

Accurate impression is very important to achieve desirable prosthesis and there are many factors in taking a good impression. For example, types of impression material, types of impression tray, impression taking methods and so on. Recently individual tooth tray technique is accepted as obtaining good impression that can be applied to multiple abutment impression, heavy salivated patient, to minimize the effect of natural teeth s undercuts and to reduce pain during cord packing procedures. The purpose of this study was to compare the accuracy according to materials and forms of the individual tooth tray which is clinically applied nowadays. Used materials in experiment were divided into 3 types (acrylic resin. $Futar^{(R)}$ occlusion. $Blu-mousse^{(R)}$) and forms were divided into 2 types (forming occlusal vent hole or not and forming marginal vent space or not). Stone master model from impression body and metal master model were measured by $X-PLAN360d^{(R)}$ to compare occlusal surface discrepancy and marginal discrepancy. The results were as follows: 1. In comparison of occlusal surface discrepancy and marginal discrepancy according to materials, groups with three materials showed no statistical difference 2. In comparison of occlusal surface discrepancy and marginal discrepancy according to occlusal vent hole, groups with occlusal vent hole showed significantly less marginal discrepancy than groups with no occlusal vent hole(p<0.05). 3. In comparison of occlusal surface discrepancy and marginal discrepancy according to 0.5mm-marginal-vent-space, groups with no 0.5mm-marginal-vent-space showed significantly less marginal discrepancy than groups with 0.5mm-marginal-vent-space (p<0.05). In summary these results suggest that individual tooth tray made of 3 types of materials with occlusal vent hole and individual tooth tray made of acrylic resin with no marginal vent space showed good accuracy of impression. In addition, individual tooth tray which is made of bite registration materials may be more useful because of advantage in facility and timesaving aspect of fabrication.