• 대한치과보철학회지
• /
• 제34권2호
• /
• pp.349-362
• /
• 1996

To determine the factors to affect on stone surface porosities produced from hydrogen gas of additional silicone, both putty and syringe type of 7 commercially different additional silicone impression materials(Blend-A-Scon, Correct VPS, Exaflex, Express, Extrude, Provil, Reprosil) were chosen and NewFujirock(GC) was poured into the impressions of detail-reproducing test block at 1, 15, 30, 45, 60 minutes after the impression materials had set and 4 specimens were made for each pouring time, each type of impression material, and each consisency and So, 280 specimens were made in total. The number of surface porosities of same area($2826 mm^2$) which were typically caused by hydrogen gas using the stereoscope(X 7.5) by two observers. Comparison of putty-syringe type and among the impression materials are tested by Kruscal-Wallis method and Mann-Whitney method(p<0.05). The results are as follows. 1. The number of porosities decreased as the pouring time of stone was delayed on both putty and syringe type of additional silicone materials. 2. The putty type significantly produced more porosities than syringe type except for the group of Reprosil.(p<0.05). 3. In case of putty type, the number of porosities increased as following order. Reprosil / Blend-A-Scon and Provil / Correct VPS and Extrude / Express and Exaflex. 4. In case of syringe type, Blend-A-Scon and Extrude produced no porosity and Exaflex and Provil at 30 minites, but Express produced porosities even at 60 minutes and the most. Additional silicone impression material releases hydrogen gas, and that fact can make the resulting die stone model useless. So, to minimize these adverse effects, it is desirable not to expose putty type of additional silicone on critical impression surface because putty type has a tendency to produce more porosities than syringe type. And it is important to have sufficient time before pouring the stone on impression because porosities produce less as time passes after setting of impression material. Also, there are differences among 7 additional silicone impression materials, so it is desirable to choose adequate brand of additional silicone for good laboratory work.

• 구강회복응용과학지
• /
• 제23권3호
• /
• pp.239-248
• /
• 2007

The accuracy and dimensional stability of rubber impression materials are very important for the fitness of the final restoration. The purpose of this investigation was to evaluate the effects of the storage time and pouring frequency of the additional silicone materials on dimensional stability. Total 30 impressions were made of tooth prepared single crown. The dies had 1 buccolingual, 1 mesiodistal and 1 occlusogingival lines. Two additional silicone materials(examixfine, aquasil) were included. 15 specimens were made of each impression material and poured by type IV stone over times(1hour, 24hours, 72hours) after mixing. 5 impressions poured after 1 hour were used for second pouring after 24hours and third pouring after 72hours. The same examiner measured each specimen 3 times after lazer scanning. All statistical tests were performed with the level of significance set at 0.05. The results indicated that significant difference at any measuring point of stone dies except the buccolingual and mesiodistal lines of the specimen made at 1hour after mixing with examixfine when measurements at 1hour, 24hours and 72hours were campared. There were significant difference between two impression materials and at every measuring point of stone dies made at second and third pouring. The length of measuring point increased significantly as time passed by and increase of the pouring frequency. However, this results are clinically acceptable except the dies of the third pouring. Under the conditions of this study, the shrinkage rate of the additional silicone rubber impression materials significantly increased as time passed by and increase of the pouring frequency.

• 대한치과의사협회지
• /
• 제41권1호통권404호
• /
• pp.35-41
• /
• 2003

Wettability of addition silicone impression material is very important property for making an accurate restoration. This study examined theimpression quality in clinical condition and the wettability of impression material. Three commercially available addition silicone impression material (Imprint; 3M, USA, Examix; GC, Japan, Perfect; Handae, Korea) were studied. A total of 90 putty/wash impressions of semi-dried premolars and wet molar teeth were examined for void production in impression body. The percentae of the sulcus reproduction ability of each material was calculated from the sulcus depths of cross-sectioned casts from the impressions with stereomicroscope. Three impression materials were used to produce die stone casts from vcid entrapment die. Voids in the stone casts were counted with the stereomicroscpe. From the experiment, the following results were obtained: 1. In direct observation, Imprint showed greatest numbers of void in impression body (P<.001).However, correlations were not found between sulcus reproduction and void production. 2. Sulcus reproduction ability of additional silicone impression material was diminished in order of Imprint, Examix, Perfect. The significant difference was found between Imprint and other material (P<.001). 3. In void entrapment laboratory test, void productions was diminished in order of Examix, Imprint, Perfect. All voids in casts were less in delayed poured cast than immediately poured cast. 4. Especially, the stone pouring time of Perfect impression material should be delayed.

• 대한치과보철학회지
• /
• 제38권2호
• /
• pp.191-199
• /
• 2000

Wettability of addition silicone impression material is very important property for making an accurate restoration. This study examined the impression quality in clinical condition and the wettability of impression and die material. Four commercially available addition silicone impression material (Express, Examix, Contrast, Perfect) and three die materials (Die-Keen, Vel-Mix, Fuji-Rock) were studied. A total of 50 putty/wash and heavy body/wash impressions of wet intact permanent molar teeth were examined for definition of the gingival sulcus reproduction and then classified in quality ranking. The percentage of the sulcus reproduction ability of each material was calculated from the sulcus depths of cross-sectioned epoxy resin casts from the impressions and clinically measured sulcus depths, The same impression materials were used to produce 3 groups of die stone casts form void entrapment die had been exposed to milk. Voids in the impression body and stone casts ere counted under a stereoscopic microscope. From the experiment, the following results were obtained : 1. Sulcus reproduction ability of additional silicone impression material were diminished in order of Express, Examix, Perfect, Contrast. The significant difference was found between Perfect and other material. Heavy body/wash combination was superior In putty/wash method n Perfect impression material. 2. In direct observation, Contrast showed least void in impression body but correlations ere not found between sulcus reproduction and void production. 3. In void entrapment laboratory test, wettability were diminished in order of Examix, Contrast, Express, Perfect. Clinical impression recording seems not to correlate with laboratory test. 4. The wettability of die material to impression material was not different in Express, Examix, Contrast. But, in Perfect, Die-Keen had superior wettability to others.

• Elastomers and Composites
• /
• 제35권1호
• /
• pp.19-28
• /
• 2000

본 연구에서는 기존 외국제품들과의 물성 비교를 통해 부가중합형 실리콘 인상재를 개발하기 위한 기초연구를 수행하였다. IR과 EDX를 이용한 인상재들의 화학적 분석, DSC와 TGA를 이용한 열적거동분석, 접촉각, 점도, 가교특성 및 기계적특성 등의 분석을 수행하여 본 연구에서 개발된 제품의 고무인상재로의 응용 가능성을 평가하였다. 기초연구 결과에 따르면 인상재에 요구되는 모든 물성을 만족하는 제품은 없었지만, 본 연구에서 개발된 인상재의 경우 인장물성 및 가교밀도 특성이 상대적으로 우수하여 인상 채득시 요구되는 기계적 특성에는 가장 잘 부합하였다. 그러나 향후 친수성 계면활성제 도입을 통한 젖음성 향상, 온도와 경화시간과의 상관관계 확립, 정확한 체적변화 및 인열강도 개선 둥의 추가적인 물성 향상이 필요한 것으로 판단되었다.

• 대한치과보철학회지
• /
• 제37권3호
• /
• pp.383-394
• /
• 1999

The indirect technique for making cast restoration requires that dies be as accurate and durable as possible. Currently, stone is the most commonly used material for die. However, it has some problems such as the weakness in its strength and low abrasion resistance. Recently, epoxy resin die systems have become available. The purpose of this study was to examine two commercially available resin die systems and evaluate some characteristics for their clinical performance. This study evaluated the dimensional accuracy of epoxy resins and their wettability with impression materials. In this study, the first experiment was about dimensional accuracy of different die materials. The master model was made of stainless steel. 10 models were made of two epoxy resins (Die-epoxy, Tri-epoxy) and a die stone (Fujirock) each. Occlusal diameter (Dimension I), occluso-gingival height (Dimension II), and interabutment distance (Dimension III) were measured in each model. Next, the contact angles of die materials with impression materials were observed. The blocks were made of polyether, hydrophilic additional silicone, polysulfide impression materials. By drop-ping the same amount (0.05ml) of Tri-epoxy, Die-epoxy, and die stone on the blocks, 10 samples of each die material were made. After setting of materials, the contact angles were measured. The results of this study were as follows. 1. The expansion of stone die and the shrinkage of resin dies in occlusal diameter were observed, and stone and Tri-epoxy were expanded and Die-epoxy was shrinked in occluso-gingival height. There was little change among materials in interabutment distance (p<0.05). 2. In comparison with the master model Tri-epoxy had the least variation in measurement of the three die systems examined. Die-epoxy was next, and die stone showed the greatest variation. 3. The compatibility of die stone for polyether, hydrophilic additional silicone, polysulfide decreased in order, wherease epoxy materials had the decreased compatibility for polyether and polysulnde, hydrophilic additional silicone in order. It was not statistically different between polyether and polysulfide (p<0.05). 4. The contact angles of Tri-epoxy, Die-epoxy, die stone were getting bigger in order.

• 대한치과보철학회지
• /
• 제39권4호
• /
• pp.351-365
• /
• 2001

For accurate impression taking, accurate impression material, solid individual tray, and bond strength between impression materials and resin tray are important factors. The purpose of this study was to evaluate tensile bond strength of rubber impression materials to various tray resin materials. This study tested the time dependent tensile bond strength between commercial brands or poly ether, polysulfide, additional silicone impression materials and commercial brands of self curing tray resin. light activited tray resin when applying adhesive Resin specimens were made with 20mm in diameter, 2mm in thickness. 1 made total 360 specimens, 10 per each group and the tensile bond strength was measured by using the Instron($M100EC^{(R)}$, Mecmesin Co., England). The results were as follows ; Comparisons of various impression materials. 1. In case of Impregum $F^{(R)}$, the bond strength of tray resin was decreased in order of SR $Ivolen^{(R)}$, Ostron $100^{(R)}$ Instant tray $mix^{(R)}$, $Lightplast^{(R)}$. All groups excluding Ostron $100^{(R)}$, Instant tray $mix^{(R)}$ are significant difference (p<0.05). Drying time after applying adhesive, the tensile bond strength of tray resin was insignificantly decreased in order of 10 min drying time group. 1 min drying time group. 5 min drying time group. 2. In case of Permlastic $regular^{(R)}$ the bond strength of tray resin was insignificantly decreased in order of Ostron $100^{(R)}$. SR $Ivolen^{(R)}$, Instant tray $mix^{(R)}$ $Lightplast^{(R)}$. About drying time after applying adhesive, the tensile bond strength of tray resin was significantly decreased in order of 5 min drying time group, 10 min drying time group, 1 min drying time group(p<0.05). 3. In case of Exaflex $regular^{(R)}$. the bond strength of tray resin was decreased in order of $Lightplast^{(R)}$, SR $Ivolen^{(R)}$, Instant tray $mix^{(R)}$, Ostron $100^{(R)}$. $Lightplast^{(R)}$ was significant difference(p<0.05). About drying time after applying adhesive, the tensile bond strength of tray resin was decreased in order of 5 min drying time group, 10 min drying time group, 1 min drying time group(p<0.05). Especially 5 min ding time group was significant difference(p<0.05). According to the results of this study, we can see the greatest tensile bond strength when using Impregrm $F^{(R)}$ and Permlastic $regular^{(R)}$ with self curing tray resin, when using Exaflex $regular^{(R)}$ with light activated tray resin In my opinion, adhesive should be dried more than 5 min before impression taking to achieve the greatest tensile bond strength.

• 대한치과보철학회지
• /
• 제40권3호
• /
• pp.236-245
• /
• 2002

The acrylic resin was first introduced as denture base materials in 1937 and it is commonly used for denture base fabrication nowadays. Three different curing cycles (Conventional curing cycle, short curing cycle and long curing cycle) and three commercially available heat-activated acrylic resins (Vertex RS, Lucitone 199 and ProBase Hot) were investigated to find the curing cycle and material that showed the minimum shrinkage of the resin during polymerization process. A brass master mold was fabricated and duplicated by additional silicone impression material. Stone molds were made by pouring of type III dental stone (SILKY-ROCK YELLOW, Whip-Mix, Louisville, Kentucky). It was embedded in the flask. Strain gauge and thermocouple were embedded in the specimen. Strain gauge and thermocouple were connected to signal conditioning amplifier and data was recorded by pre-programmed software. The parameters ESmax (Maximum expansion strain), Sb (Strain measured just before deflasking procedure), Sa (Strain measured just after deflasking procedure) and Sf (Strain measured at the end of the experiment) were measured. ${\Delta}$S was calculated from Sb and Sa (${\Delta}$S=Sb-Sa). In the experiment concerned about materials, the parameters 90-ESmax (Maximum expansion strain measured during early 90 minutes of curing procedure), 180-ESmax (Maximum expansion strain measured from 90 minutes to 180 minutes), Sb, Sa, ${\Delta}$S and Sf were measured and the following conclusions were made. 1. The ESmax value of conventional curing cycle showed the largest value and the 180-ESmax value of Lucitone 199 showed the smallest value. 90-ESmax values showed no significant difference (p<0.05). 2. ${\Delta}$S values of conventional curing cycle showed the positive values. ${\Delta}$S values of short curing cycle and long curing cycle showed the negative values. All three materials cured by conventional curing cycle showed the positive values. 3. The Sf values of long curing cycle and ProBase Hot (cured by conventional curing cycle) showed the smallest values.

• 대한치과보철학회지
• /
• 제46권2호
• /
• pp.201-208
• /
• 2008

연구목적: 시멘트 유지형 지대주를 인상용 코핑으로 이용하고 레진이나 금속 구조물에 접착하여 스플린팅하는 새로운 인상법을 시도하였다. 연구의 목적은 첫 번째, 3개의 임플랜트가 $15^{\circ}$ 경사지게 식립된 모형에서 closed tray 인상법과 레진 스플린팅한 open tray 인상법의 정확성을 비교하는 것이고 두 번째, 새로운 인상법의 정확성을 앞의 두 가지 인상법과 비교하는 것이다. 연구 재료 및 방법: 3개의 임플랜트 아날로그가 선상으로 배열되고 가운데 아날로그는 모형에 수직이고 양쪽 끝 아날로그는 이것에 앞뒤로 $15^{\circ}$ 경사지게 배열된 주모형과 주모형에 잘 적합되는 기준구조물을 제작하였다. closed tray 인상법, 레진 스플린팅한 open tray 인상법, 지대주-레진구조물 접착 인상법, 지대주-금속구조물 접착 인상법, 각 10개씩 40번의 인상을 채득하여 복제모형을 제작하였다. 이미지 처리할 수 있는 광학 현미경을 이용하여 기준구조물과 복제모형내의 아날로그와의 수직간격을 측정하여 인상의 정확성을 평가하였다. 통계처리는 one-way ANOVA와 사후 검정으로 Tukey test를 5% 유의수준으로 시행하였다. 결과: closed tray 인상법;74.3 (${\pm}33.4$)${\mu}m$의 간격은 레진 스플린팅한 open tray 인상법과 다른 두 가지 새로운 인상법보다 간격의 크기가 통계적 유의성 있게 컸다(P<.05). 지대주-금속구조물 접착 인상법;42.5 (${\pm}11.9$)${\mu}m$은 다른 인상법들 보다 간격의 크기가 통계적 유의성 있게 작았다(P<.05). 지대주-레진구조물 접착 인상법;51.0 (${\pm}14.1$)${\mu}m$은 레진 스플린팅한 open tray 인상법50.3 (${\pm}16.9$)${\mu}m$과 통계적 유의성 있는 차이를 보이지 않았다(P>.05). 결론: 이 연구의 한계 내에서, 레진 스플린팅한 open tray 인상법은 closed tray 인상법보다 우수한 정확성을 나타내었고, 지대주를 금속구조물에 접착하는 새로운 인상법의 정확성은 레진 스플린팅한 open tray 인상법보다 우수하였다.