• Journal of Dental Rehabilitation and Applied Science
• /
• v.21 no.1
• /
• pp.83-93
• /
• 2005

This study was designed to investigate the fitness of adjustable dental impression trays. The size and shape of these trays were designed from the results of the dental arch size of Korean adults. Tray samples were made by CAD-CAM working. A hundred dental students(male:50, female:50) were selected for taking irreversible hydrocolloid impression using these trays. The author measured the width and length of impression material on the several measuring points. The results obtained were as follows : 1. Uniform impression material thickness was achieved by controlling the width of the tray using stops and beveled guides. 2. In the upper tray, the impression material thickness was measured to be rather great showing thickness of the labial vestibule 8.3 mm and the midpalatal part 8.6 mm. 3. In the lower tray, length of the impression material of the labial vestibule of first, second premolar contact point was 7.8 mm, and thickness of the lingual part of premolars(1.8 mm) and molars(1.9 mm) showed small values. 4. In the lower tray, the impression material thickness of the buccal shelf area(0.2 mm) and the retromolar pad area(0.6 mm) was measured to be too small.

• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.4
• /
• pp.477-487
• /
• 2006

Purpose : this study was to evaluate the fitness of adjustable dental impression trays on the Koreans : the trays used in the previous study by Kim et al. as part of the dental adjustable tray development project were improved and modified. Material and method: The patterns of tray were made through CAD-CAM process, and a simple silicone-base molds were made from them. The trial products were reproduced by pouring polyurethane into these molds. 30 male students(Wonkwang University, Dental College) and 30 female students (Wonkwang Health Science College, Department of Dental Hygiene) were selected and Reversible hydrocolloid impression materials were used for this study. The fitness of the trays was evaluated by measuring the width and length of impression materials of each measurement sites. Results and conclusion : 1. In adapting the trays inside the mouth, a uniform width of impression material(3 $\sim$ 6mm) was obtained in most sites due to the tooth stops and the inclined planes accommodating the width of the tray 2. The thickness of impression material in the central part of the palate was a mean 9.8mm, which turned out to be somewhat thick. 3. In the mandible. the thickness of the impression material in the lingual side inferior to the contact point of the 1st and 2nd molars was 2.7mm, and the thickness of the material in the lingual side of the rearmost margin was 2.5 mm. The thickness of the impression material of these areas was relatively thin.

• The Journal of the Korean dental association
• /
• v.41 no.1 s.404
• /
• 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.

• The Journal of Korean Academy of Prosthodontics
• /
• v.45 no.3
• /
• pp.389-400
• /
• 2007

Statement of problem. Use of the conventional dental impression procedure is problematic in patients who have difficulty opening their mouth, difficulty breathing through their nose or tendency to gag. Purpose. It is necessary to make individual trays more comfortable for patients during impression taking procedure. It was reported at the KAP Annual Meeting 2001 Seoul that an improved impression technique was suitable for this purpose. In this study, the accuracy of the improved dental impression method for implant was compared with the conventional dental impression method. Material and methods. An oral simulator was made from clear acrylic resin block which had similar form of edentulous ridge. For setting up the standard, five fixtures were installed on it. Study casts were made using two kinds of impression techniques. One was the conventional method that was taken using silicone impression material and an individual resin tray under connection of inter-fixture relation. The other was the improved method in which was the connection of the impression coping and the thermoformed polymethyl methacrylate tray. In addition, two different study casts were made from the improved impression body. The coordinates of the fixture on the study model were measured by three-dimensional coordinate measuring equipment. Then the distances between each fixture were calculated and compared with that of oral simulator. Accuracy of the each impression method was also assessed. Results. The differences of inter-fixture dimension between study casts and simulator in the improved impression technique showed $0.014{\pm}0.016mm$ and $0.017{\pm}0.022mm$, respectively and that of the conventional method was $0.017{\pm}0.014mm$. There was no significant difference between the improved impression technique and conventional method. Conclusion. The improved impression technique is useful for multiple support implants.

• Journal of Korean society of Dental Hygiene
• /
• v.8 no.2
• /
• pp.53-66
• /
• 2008

There was to purpose of this study improves analyzing cause that prosthesis brings bite engaging that is inaccurate in patient's mouth, when supposed that all conducts that do in operatory and dental laboratory are perfect. Impression did check bite by alginate impression material and polymerization style silicon impression material that use usually in presence at a sickbed Irreversibility, hydrocolloid, alginate impression material washed in flowing water and poured anhydrite after wait about 8 minutes so that region that charge interest after impression check bite may become undoing. And hydrophile property addition polymerization style impression material poured anhydrite after blow 30 considering impression material dwell time and H2 gas occurrence time (5~15 minute) after have washed in flowing water. I got each 7 models, result that manufactures total 28 and measures by third dimension measuring instrument (Meteo, Korea) following sequence curing in tray holder and floor 1, By Alginate impression when is hardened in tray holder and when is hardened in the floor after do check bite, SPH 4, SPH5 all as there is synonymy appeared(P<0.05). By in case do not use average 0.1741 in case use tray holder in 0.0447 SPH5s in case do not use average 0.2838 pastas in case use tray holder in SPH4 0.0309, When did not use both SPH4 and SPH5 tray holder, when used tray holder, 1 appeared more greatly. 2. By amity sex addition polymerization style silicon impression when is hardened in tray holder after do check bite and when is hardened in the floor SPH 4, a11 of the SPH5s very big synonymy be(P>0.05). And in case use tray holder in 0.000657 pasta SPH5s in case do not use average 0.000129 pastas in case use tray holder in SPH4 average 0.000114 pastas, by in case do not use 0.000757, I appeared more greatly when used tray when did not use both SPH4 and SPH5 tray holder, but 1 appeared is not level to keep in mind(Table 8~9). 3 SPH4 was looked very big mindfulness in model that manufacture doing impression check bite by Alginate and model that do impression check bite by amity sex accessory penalty silicon without using tray holder(P< 0.001). I use tray holder and SPH4 did not appear synonymy in model that manufacture doing impression check bite by Alginate and model that do impression check bite by amity sex accessory penalty silicon(P>0.05). Study finding of above when see synthesis Alginate certainly tray holder use must and I could know that hardening method does not exert big influence on volume stability if remove impression sieve of excess because amity sex accessory penalty silicon passes over tray, Also, Alginate impression material previewed can get heading a conspiracy style that volume stability of accessory penalty silicon impression material degree is if use tray holder.

• The Journal of the Korean dental association
• /
• v.55 no.1
• /
• pp.72-81
• /
• 2017

Regardless of the type of impression being made, the tray is the most important part of the impression-making procedure for completely edentulous patients. Dentists have to make use of a combination of rigid, thermoplastic, and resilient materials and control step-by-step procedure from irreversible hydrocolloid impression to definitive cast fabrication. For successful edentulous impression, some considerable clinical tips were guided.

• Journal of Industrial Technology
• /
• v.36
• /
• pp.45-48
• /
• 2016

The purpose of this study is to evaluate and compare wettability and setting time of twelve polyvinylsiloxane impression pastes. For comparing the wettability, the contact angle of a water drop on the impression materials was measured. It is important for impression materials to have higher wettability when trying to make impressions of interproximal spaces and gingival crevices. The higher wettability the better the material will flow into these spaces and the more accurate the impression. An ideal impression material will have adequate working time but a fast intraoral setting time. The clinician needs time to inject material into the sulcus, place the impression material into the tray and position it in the mouth, but the material should set rapidly to reduce time in the patient's mouth. It is considered that the results obtained in this study will provide guideline information for the manufacturing of impression materials and for selecting appropriate impression materials.

• The Journal of Korean Academy of Prosthodontics
• /
• v.27 no.2
• /
• pp.131-141
• /
• 1989

This study was designed to investigate the fitness of stock tray in Korean adults. 107 dental students (male: 87, female: 20) who have normal occlusion and symmetric facial fom were selected. The upper and lower stock tray (Osungtray, Osung Co., Korea) fit with dental arch were selected for taking irreversible hydrocolloid impression. The author measured the thickness of impression material about two items, that is, width and length on the flange of stock tray. Several measuring points on the dental arches and palatal area were checked with Goldman Fox prove (Hu-Friedy, U.S.A.). The obtained results were as follows: 1. The width of impression material on buccal flange of upper and lower trays were narrower than any other measuring point, but the thickness of impression material on the palatal area of upper stock tray was the widest of all measuring points. 2. The length on buccal flange of lower stock tray was shorter, but the length on tray flange of lower stock tray at lingual frenum area was longer. 3. On upper dental arch, the upper extra-large tray was used in 53% of subjects, but upper small tray was not used. 4. On lower dental arch, the large tray was used in 55% of subjects. 5. There was not adequate tray on upper dental arch in 4 subjects.

• The Journal of Advanced Prosthodontics
• /
• v.3 no.4
• /
• pp.177-185
• /
• 2011

PURPOSE. The aim of this study was to evaluate the effect of dimensional stability of splinting material on the accuracy of master casts. MATERIALS AND METHODS. A stainless steel metal model with 6 implants embedded was used as a master model. Implant level impressions were made after square impression copings were splinted using 5 different techniques as follows. (1) Splinted with autopolymerizing resin and sectioned, reconnected to compensate polymerization shrinkage before the impression procedure. (2) Splinted with autopolymerizing resin just before impression procedure. (3) Primary impression made with impression plaster and secondary impression were made over with polyether impression material. (4) Splinted with impression plaster. (5) Splinted with VPS bite registration material. From master model, 5 impressions and 5 experimental casts, total 25 casts were made for each of 5 splinting methods. The distortion values of each splinting methods were measured using coordinate measuring machine, capable of recordings in the x-, y-, z- axes. A one-way analysis of variance (ANOVA) at a confidence level of 95% was used to evaluate the data and Tukey's studentized range test was used to determine significant differences between the groups. RESULTS. Group 1 showed best accuracy followed by Group 3 & 4. Group 2 and 5 showed relatively larger distortion value than other groups. No significant difference was found between group 3, 4, 5 in x-axis, group 2, 3, 4 in y-axis and group 1, 3, 4, 5 in z-axis (P<.0001). CONCLUSION. Both Splinting impression copings with autopolymerizing resin following compensation of polymerization shrinkage and splinting method with impression plaster can enhance the accuracy of master cast and impression plaster can be used simple and effective splinting material for implant impression procedure.

• Elastomers and Composites
• /
• v.36 no.2
• /
• pp.102-110
• /
• 2001

The three types of surfactants such as nonylphenoxy poly(ethylene) ethanol homologues, caster oil poly(ethylene) ethanol homologues, and sodium perfluoroalkyl carboxylates are used to improve the wettability of rubber impression material. Among the surfactants, the usage of sodium perfluoroalkyl carboxylates containing fluoro group resulted in the lowest surface energy of impression material and the result gave the positive effect on the wettability of rubber impression material to teeth. Also, the anti-foaming agents were used to reduce or remove the hydrogen gas generating on the impression material by reaction. In the case of rubber impression material containing sodium perfluoroalkyl carboxylate as a surfactant, it was found that the tear strength of rubber impression material increased over 3 N/mm with the addition of anti-forming agent. Therefore, the anti-foaming agent could contribute to the mechanical property of rubber impression material without the change of surface property.