1.Influence of cavity size and restoration methods on the cusp deflection in composite restoration.
Mi Ra LEE ; In Bog LEE ; Chang In SEOK ; Sang Tag LEE ; Chung Moon UM
Journal of Korean Academy of Conservative Dentistry 2004;29(6):532-540
The aim of this study was to measure the cusp deflection during composite restoration for MOD cavity in premolar and to examine the influence of cavity dimension, C-factor and restoration method on the cusp deflection. Thirty extracted maxillary premolar were prepared to four different sizes of MOD cavity and divided into six groups. The width and depth of the cavity were as follows. Group 1; 1.5 x 1 mm, Group 2; 1.5 x 2 mm, Group 3; 3 x 1 mm, and Group 4-6; 3 x 2 mm respectively. Group 1-4 were restored using bulk filling method with Z-250 composite. However, Group 5 was restored incrementally, and Group 6 was restored with an indirect resin inlay. The cusp deflection was recorded at the buccal and lingual cusp tips using LVDT probe for 10,000 seconds. The measured cusp deflections were compared between groups, and the relationship between the cube of the length of cavity wall/the cube of the thickness of cavity wall (L3 / T3), C-factor and cusp deflection or %flexure (100 x cuspal deflection / cavity width) was analyzed. The cusp deflection of Group 1-4 were 12.1 microm, 17.2 microm, 16.2 microm and 26.4 microm respectively. The C-factor was related to the %flexure rather than the cusp deflection. There was a strong positive correlationship between the L3 / T3 and the cusp deflection. The cusp deflection of Group 5 and 6 were 17.4 microm and 17.9 microm respectively, which are much lower value than that of Group 4.
Bicuspid
;
Inlays
2.The effect of reinforcing methods on fracture strength of composite inlay bridge.
Chang Won BYUN ; Sang Hyuk PARK ; Sang Jin PARK ; Kyoung Kyu CHOI
Journal of Korean Academy of Conservative Dentistry 2007;32(2):111-120
The purpose of this study is to evaluate the effects of surface treatment and composition of reinforcement material on fracture strength of fiber reinforced composite inlay bridges. The materials used for this study were I-beam, U-beam TESCERA ATL system and ONE STEP(Bisco, IL, USA). Two kinds of surface treatments were used; the silane and the sandblast. The specimens were divided into 11 groups through the composition of reinforcing materials and the surface treatments. On the dentiform, supposing the missing of Maxillary second pre-molar and indirect composite inlay bridge cavities on adjacent first pre-molar disto-occlusal cavity, first molar mesio-occlusal cavity was prepared with conventional high-speed inlay bur.The reinforcing materials were placed on the proximal box space and build up the composite inlay bridge consequently. After the curing, specimen was set on the testing die with ZPC. Flexural force was applied with universal testing machine (EZ-tester; Shimadzu, Japan). at a cross-head speed of 1 mm/min until initial crack occurred. The data wasanalyzed using one-way ANOVA/Scheffes' post-hoc test at 95% significance level. Groups using I-beam showed the highest fracture strengths (p < 0.05) and there were no significant differences between each surface treatment (p > 0.05). Most of the specimens in groups that used reinforcing material showed delamination. 1. The use of I-beam represented highest fracture strengths (p < 0.05). 2. In groups only using silane as a surface treatment showed highest fracture strength, but there were no significant differences between other surface treatments (p > 0.05). 3. The reinforcing materials affect the fracture strength and pattern of composites inlay bridge. 4. The holes at the U-beam did not increase the fracture strength of composites inlay bridge.
Inlays*
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Molar
4.The study of onlay bone graft with cancellous chip bone in nonunion of the long bones.
Soo Kil KIM ; Keung Bae RHEE ; Sae Jung OH ; Sang Won ROH
The Journal of the Korean Orthopaedic Association 1991;26(4):1145-1153
No abstract available.
Inlays*
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Transplants*
5.The evaluation of color and color difference according to the layering placement of Incisal shade composites on the body composites of the indirect resin restoration.
Su Jung PARK ; Han Young LEE ; Myong Yun NAH ; Hoon Sang CHANG ; Yun Chan HWANG ; Won Mann OH ; In Nam HWANG
Journal of Korean Academy of Conservative Dentistry 2011;36(1):37-49
OBJECTIVES: The aim of this study was to evaluate the surface color of indirect resin restoration according to the layering placement of different shade of incisal composite. MATERIALS AND METHODS: In this study, CIE L*a*b* value of 16 Body composite of Tescera ATL (Bisco, Schaumburg IL,USA) was measured by spectrophotometer (NF999, Nippon Denshuku, Japan), and compared to CIE L*a*b* value of Vitapan shade guide. Nine shade Incisal composite of Tescera ATL were build-up to 1 mm thickness on Body composites inlay block, and CIE L*a*b* value was measured. Incisal composite was ground to 0.5 mm thickness and CIE L*a*b* value was re-measured. Color difference between Body composite and Incisal composites layered on Body composite was calculated as a function of thickness. RESULTS: Color difference between corresponding shade of Tescera Body composite and Vitapan shade guide was from 6.88 to 12.80. L* and b*value was decreased as layering thickness of Incisal composite on Body composite was increased. But, a* value did not show specific change tendency. CONCLUSIONS: Surface color difference between Body composites and Incisal composites layered on Body composite was increased as the layering thickness of Incisal composite increased (p < 0.05).
Composite Resins
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Inlays
6.Influence of three different preparation designs on the marginal and internal gaps of CEREC3 CAD/CAM inlays.
Deog Gyu SEO ; Young Ah YI ; Yoon LEE ; Byoung Duck ROH
Journal of Korean Academy of Conservative Dentistry 2009;34(3):177-183
The aim of this study was to evaluate the marginal and internal gaps in CEREC3 CAD/CAM inlays of three different preparation designs. CEREC3 Inlays of three different preparation designs (n = 10) were fabricated according to Group I-conventional functional cusp capping/shoulder preparation, Group II-horizontal reduction of cusps and Group III-complete reduction of cusps/shoulder preparation. After cementation of inlays, the bucco-lingual cross section was performed through the center of tooth. Cross section images of 20 magnifications were obtained through the stereomicroscope. The gaps were measured using the Leica application suite software at each reference point. Statistical analysis was performed using one-way ANOVA and Tukey's test (alpha<0.05). The marginal gaps ranged from 80.0 to 97.8 microm for Group I, 42.0 to 194.8 microm for Group II, 51.0 to 80.2 microm for Group III. The internal gaps ranged from 90.5 to 304.1 microm for Group I, 80.0 to 274.8 microm for Group II, 79.7 to 296.7 microm for Group III. The gaps of each group were the smallest on the margin and the largest on the horizontal wall. For the CEREC3 CAD/CAM inlays, the simplified designs (groups II and III) did not demonstrate superior results compared to the traditional cusp capping design (group I).
Cementation
;
Inlays
;
Tooth
7.A study on the machining accuracy of dental digital method focusing on dental inlay
Eun Jeong BAE ; Il Do JEONG ; Woong Chul KIM ; Ji Hwan KIM
The Journal of Advanced Prosthodontics 2018;10(4):321-327
PURPOSE: The purpose of this study was to compare the cutting method and the lamination method to investigate whether the CAD data of the proposed inlay shape are machined correctly. MATERIALS AND METHODS: The Mesial-Occlusal shape of the inlay was modeled by changing the stereolithography (STL). Each group used SLS (metal powder) or SLA (photocurable resin) in the additive method, and wax or zirconia in the subtractive method (n=10 per group, total n=40). Three-dimensional (3D) analysis program (Geomagic Control X inspection software; 3D systems) was used for the alignment and analysis. The root mean square (RMS) in the 2D plane state was measured within 50 µm radius of eight comparison measuring points (CMP). Differences were analyzed using one-way analysis of variance and post-hoc Tukey's test were used (α=.05). RESULTS: There was a significant difference in RMS only in SLA and SLS of 2D section (P < .05). In CMP mean, CMP 4 (−5.3±46.7 µm) had a value closest to 0, while CMP 6 (20.1±42.4 µm) and CMP 1 (−89.2±61.4 µm) had the greatest positive value and the greatest negative value, respectively. CONCLUSION: Since the errors obtained from the study do not exceed the clinically acceptable values, the lamination method and the cutting method can be used clinically.
Inlays
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Methods
;
Radius
8.Power density of various light curing units through resin inlays with modified layer thickness.
Sung Ok HONG ; Yonghui OH ; Jeong Bum MIN ; Jin Woo KIM ; Bin Na LEE ; Yun Chan HWANG ; In Nam HWANG ; Won Mann OH ; Hoon Sang CHANG
Restorative Dentistry & Endodontics 2012;37(3):130-135
OBJECTIVES: The purpose of this study was to enhance curing light penetration through resin inlays by modifying the thicknesses of the dentin, enamel, and translucent layers. MATERIALS AND METHODS: To investigate the layer dominantly affecting the power density of light curing units, resin wafers of each layer with 0.5 mm thickness were prepared and power density through resin wafers was measured with a dental radiometer (Cure Rite, Kerr). The dentin layer, which had the dominant effect on power density reduction, was decreased in thickness from 0.5 to 0.1 mm while thickness of the enamel layer was kept unchanged at 0.5 mm and thickness of the translucent layer was increased from 0.5 to 0.9 mm and vice versa, in order to maintain the total thickness of 1.5 mm of the resin inlay. Power density of various light curing units through resin inlays was measured. RESULTS: Power density measured through 0.5 mm resin wafers decreased more significantly with the dentin layer than with the enamel and translucent layers (p < 0.05). Power density through 1.5 mm resin inlays increased when the dentin layer thickness was reduced and the enamel or translucent layer thickness was increased. The highest power density was recorded with dentin layer thickness of 0.1 mm and increased translucent layer thickness in all light curing units. CONCLUSIONS: To enhance the power density through resin inlays, reducing the dentin layer thickness and increasing the translucent layer thickness would be recommendable when fabricating resin inlays.
Dental Enamel
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Dentin
;
Inlays
;
Light
9.Comparative analysis on reproducibility among 5 intraoral scanners: sectional analysis according to restoration type and preparation outline form.
The Journal of Advanced Prosthodontics 2016;8(5):354-362
PURPOSE: The trueness and precision of acquired images of intraoral digital scanners could be influenced by restoration type, preparation outline form, scanning technology and the application of power. The aim of this study is to perform the comparative evaluation of the 3-dimensional reproducibility of intraoral scanners (IOSs). MATERIALS AND METHODS: The phantom containing five prepared teeth was scanned by the reference scanner (Dental Wings) and 5 test IOSs (E4D dentist, Fastscan, iTero, Trios and Zfx Intrascan). The acquired images of the scanner groups were compared with the image from the reference scanner (trueness) and within each scanner groups (precision). Statistical analysis was performed using independent two-samples t-test and analysis of variance (α=.05). RESULTS: The average deviations of trueness and precision of Fastscan, iTero and Trios were significantly lower than the other scanners. According to the restoration type, significantly higher trueness was observed in crown and inlay than in bridge. However, no significant difference was observed among four sites of preparation outline form. If compared by the characteristics of IOS, high trueness was observed in the group adopting the active triangulation and using powder. However, there was no significant difference between the still image acquisition and video acquisition groups. CONCLUSION: Except for two intraoral scanners, Fastscan, iTero and Trios displayed comparable levels of trueness and precision values in tested phantom model. Difference in trueness was observed depending on the restoration type, the preparation outline form and characteristics of IOS, which should be taken into consideration when the intraoral scanning data are utilized.
Crowns
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Dentists
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Humans
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Inlays
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Jupiter
;
Tooth
10.Rigid Fixation of Methylmethacrylate on Cranioplasty: Internal Screw-Locking Method.
Won Jai LEE ; Yil PARK ; Beyoung Yun PARK
Journal of the Korean Society of Plastic and Reconstructive Surgeons 2003;30(5):541-544
Methylmethacrylate has been proven to be successful in craniofacial alloplastic contouring surgery over several decades. Especially, for the patient with only forehead irregularity after the skull trauma, the alloplastic contouring surgery with methylmethacrylate onlay implant is the choice of treatment. The major advantage of methylmethacrylate is that it is completely malleable in the initial stages of hardening, thus permitting an optimal contouring. However, due to its incapability of direct bonding to the surrounding tissues and consequent lack of fixation, additional fixation technique is necessary. Several different methods have been established to prefabricate methylmethacrylate for cranioplasty, but they are complex; no one-stage procedure. In case of forehead irregularity we performed craniofacial contouring using methylmethacrylate and fixation with internal screw-locking method. Firm fixation, molding in situ, and easiness of manipulation are potential advantages over previously established methods.
Forehead
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Fungi
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Humans
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Inlays
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Methylmethacrylate*
;
Skull