PURPOSE: The objective of this study was to evaluate and compare the accuracy of impression body taking by the closed and the open tray impression technique with 3 types of impression tray. Individual tray, metal stock tray and polycarbonate tray were used. MATERIALS AND METHODS: Nine closed tray impressions were taken by individual tray, metal stock tray and polycarbonate stock tray, respectively with polyether impression material. 9 open tray impressions were also acquired by same manner. Precision analysis on the master models was performed by attaching the reference frameworks with alternate single screws and measuring the vertical fit discrepancy of respective analogues in working cast with a stereo microscope. Data were analyzed by 1 way ANOVA and independent t-test. RESULTS: The average fit accuracy of impression bodies was calculated. With the closed tray impression technique, there were significant statistical differences in vertical fit discrepancy according to the types of tray. The individual tray group showed the lowest value and the polycarbonate stock tray group represented the highest. With the open tray impression technique, there was no significant difference in vertical fit discrepancy. Significant statistical difference in vertical fit discrepancy was found between the open and the closed impression technique with the polycarbonate stock tray. CONCLUSION: From the results above, more precise impressions could be acquired by the rigid individual tray compared with the polycarbonate stock tray. It was hard to get consistent accuracy impressions by the closed tray impression technique with polycarbonate stock trays.
Dental Impression Technique ; Polycarboxylate Cement

In this study, the effects of surface pre-treatment and adhesive type on the shear bond strength between PEKK (polyetherketoneketone) and zirconia were analyzed by means of shear bond test and fracture aspect analysis. RI group (sand blasted with 110 µm Rocatec + silane primer applied + Premier implant cement) showed the highest shear bond strength value (9.01 MPa), followed by AI (7.94 MPa), NI (5.62 MPa), RT (2.71 MPa), AT (2.25 MPa), and NT (non-treated + Hy-bond, 1.96 MPa) groups showed the lowest values. Analysis of shear bond strength according to the type of cement showed that the group using resin cement for implant was higher than the group bonded with polycarboxylate cement regardless of the surface treatment (p < 0.05). As a result of analysis of shear bond strength according to the surface treatment, the silane primer applied to the surface of 110 µm particle size Rocatec showed the highest value (p < 0.05). The fracture patterns of the specimens were analyzed by surface treatment and cement type. Polycarboxylate cement showed better bond strength with zirconia specimen and resin cement showed higher bond strength with PEKK specimen.
Adhesives ; Particle Size ; Polycarboxylate Cement ; Resin Cements

PURPOSE: In this study, the shear bond strengths (SBS) of luting cements to fixed superstructure metal surfaces under various seating forces were investigated. MATERIALS AND METHODS: Seven different cements [Polycarboxylate (PCC), Glass-Ionomer (GIC), Zinc phospahate (ZPC), Self-adhesive resin (RXU), Resin (C&B), and Temporary cements ((RXT) and (TCS))] were bonded to a total number of 224 square blocks (5×5×3 mm) made of one pure metal [Titanium (CP Ti) and two metal alloys [Gold-Platinum (Au-Pt) and Cobalt-Chrome (Co-Cr)] under 10 N and 50 N seating forces. SBS values were determined and data were analyzed with 3-way ANOVA. Pairwise comparisons and interactions among groups were analyzed with Tukey's simultaneous confidence intervals. RESULTS: Overall mean scores indicated that Co-Cr showed the highest SBS values (1.96±0.4) (P < .00), while Au-Pt showed the lowest among all metals tested (1.57±0.4) (P < .00). Except for PCC/CP Ti, RXU/CP Ti, and GIC/Au-Pt factor level combinations (P < .00), the cements tested under 10 N seating force showed no significantly higher SBS values when compared to the values of those tested under 50 N seating force (P>.05). The PCC cement showed the highest mean SBS score (3.59±0.07) among all cements tested (P < .00), while the resin-based temporary luting cement RXT showed the lowest (0.39±0.07) (P < .00). CONCLUSION: Polycarboxylate cement provides reliable bonding performance to metal surfaces. Resin-based temporary luting cements can be used when retrievability is needed. GIC is not suitable for permanent cementation of fixed dental prostheses consisting of CP Ti or Au-Pt substructures.
Alloys ; Cementation ; Dental Prosthesis ; Metals ; Polycarboxylate Cement ; Zinc

Ultrasonic instruments transfer electrical energy to mechanical energy resulting in vibration used for various dental treatments. If we could know the effect of ultrasonic instruments on the dental cements within the cast crown, we could take care when conducting periodontal surgery and when using the ultrasonic instruments to remove cast crown, it would be much more convenient. The purpose of this study was to compare the bond strength of several dental cements according to ultrasonic instrumentation time In this study 4 types of cements were used to cement the specimens. They were treated with ultrasonic instrumentation for 0-5 minutes and the change in bond strength were statistically compared The results were as follows : 1. The tensile bond strength of zinc phosphate cement decreased according to the increase in time of ultrasonic instrument and showed significant differance between 0 minutes and the others and between 1 minute and 2,3,4,5 minutes (P<0.05) 2. The tensile bond strength of polycarboxylate cement decreased according to the increase in time of ultrasonic instrument and showed significant differance between 5 minutes and the others and between 4 minute and 0 minutes (P<0.05) 3. The tensile bond strength of zinc phosphate cement decreased according to the increase in time of ultrasonic instrument and showed significant differance between 5 minutes and the others (P<0.05) 4. The tensile bond strength of resin cement showed no statistically differences according to the ultrasonic instrumentation time In conclusion, it this considered that zinc phosphate cement is most affected by ultrasonic instrumentations and resin cement is the least affected. When using ultrasonic instruments the result above should be used as an index.
Crowns ; Dental Cements* ; Polycarboxylate Cement ; Resin Cements ; Ultrasonics* ; Vibration ; Zinc Phosphate Cement

The purpose of this study was to confirm the formation of hybrid layer and resin tags in dentin tissue and the possibility of bonding between luting cements used for the prosthesis and the resinous surface coated with resin bonding agents to prevent the dentin hypersensitivity after abutment preparation. Some resin bonding agents, which may have the possibility of bonding with polyacrylic acid as a liquid ingredient of polycarboxylate and glass ionmer coments, were selected. All-Bond desenstizer containing NTG-GMA and BPDM, Scotch-Bond Multipurpose plus containing HEMA, and XR-bond cotaining organophosphate were selected as a coating agent. Dental cements were zinc phosphate, polycarboxylate, and glass ionomer cement. After the exposed dentin surface of premolars was ethced with 10% phosphoric acic and coated with resin bonding agents, the monophology of treated surfaces and the resin tags and hybrid layers on sectioned surfaces were observed by SEM. Shear bond strength between the resin bonding agents and 3 kinds of cements was measured 24 hours after bonding. On the debonded surfaces of the shear bond strength tested specimens, the cement tags and the bonding sites between the resin materials and cements were examined by SEM. Following conclusions were drawn : 1. Coating of dentin with resin bonding agents had no effect on the shear bond strength of zinc phosphate cement. 2. Both of polycarboxylate and glass ionomer cements showed the increased shear bond strength by the dentinal coating with Scotch-Bond Multipurpose plus containing HEMA. However, in the case of dentinal coating with some agents containing NTG-GMA and BPDM or organophosphate, polycarboxylate cement exhibited the lowered shear bond strength, and glass ionomer cement showed the unchanged shear bond strength. 3. Complete obstructions of dentinal tubules were observed on the dentin coasted with All-Bond desensitizer or XR-bond, but distinct shape of the orifices of dentinal tubules was observed consistently on the dentin coated with Scotch-Bond Multipurpose plus 4. The hybrid layer was thickest on the dentin coated with All-Bond desensitizer, and the length of resin tags was longest one the dentin coated with Scotch-Bond Multipurpose plus. 5. On the debonded specimens which had been bonded with polycarboxylate cement or glass ionomer cement after coating with Scotch-Bond Multipurpose plus, the cement tags and the bonding sites between the resinous surface and the cements could be examined.
Acyclovir ; Bicuspid ; Dental Cements ; Dentin Sensitivity ; Dentin* ; Glass ; Glass Ionomer Cements ; Polycarboxylate Cement ; Prostheses and Implants ; Zinc ; Zinc Phosphate Cement

Bond strength of luting cements to dentin is a critical consideration for success of complete cast crowns. This study was performed to evaluate the relationship between surface characteristics of teeth prepared for complete cast crowns and retention of cemented restorations. Eighty artificial crowns were cast for standardized complete crown tooth preparations accomplished with the use of a special device on recently extracted human teeth. Coarse diamond(#102R, Shofu) and superfine finishing diamond(#SF102R, Shofu) burs of similar shape were used. Crowns in each group were randomly subdivided into four subgroups of 10 for luting cements selected for this study: zinc phosphate cement (FLECK'S), polycarboxylate cement (Poly-F), reinforced glass ionomer cement (Fuji PLUS), and adhesive resin cement (Panavia 21). Retention was evaluated by measuring the tensile load required to dislodge the artificial crown from tooth preparations with an Instron testing machine, and analysed by one-way ANOVA and Student's t-test. The obtained results were as follows ; 1. When tooth preparation was done with coarse diamond bur, retentive force was diminished in order of Panavia 21, Fuji PLUS, FLECK'S, and Poly-F. Retentive forces showed the significant difference between Fuji PLUS group and FLECK'S group(p<0.001). 2. When tooth preparation was done with superfine diamond bur, retentive force was diminished in order of Fuji PLUS, Panavia 21, FLECK'S and Poly-F. Retentive forces showed the significant difference between Panavia 21 group and FLECK'S group(p<0.001). 3. Retentive force in coarse tooth surfaces was significantly higher than that in superfine tooth surface with all luting cements(p<0.001), and cement residues were almost retained with in the cast crown in all groups.
Adhesives ; Crowns* ; Dental Instruments ; Dentin ; Glass Ionomer Cements ; Humans ; Polycarboxylate Cement ; Resin Cements ; Tooth Preparation ; Tooth* ; Zinc Phosphate Cement

OBJECTIVES: The objective of this study is to investigate the distribution patterns and exposure concentrations of bioaerosols in industries suspected to have high levels of bioaerosol exposure. METHODS: We selected 11 plants including 3 livestock feed plants (LF industry), 3 metal working fluids handling plants (MWFs industry), and 5 sawmills and measured total airborne bacteria, fungi, endotoxins, as well as dust. Airborne bacteria and fungi were measured with one stage impactor, six stage cascade impactor, and gelatin filters. Endotoxins were measured with polycarbonate filters. RESULTS: The geometric means (GM) of the airborne concentrations of bacteria, fungi, and endotoxins were 1,864, 2,252 CFU/m3, and 31.5 EU/m3, respectively at the sawmills, followed by the LF industry (535, 585 CFU/m3, and 22.0 EU/m3) and MWFs industry (258, 331 CFU/m3, and 8.7 EU/m3). These concentrations by industry type were significantly statistically different (p < 0.01). The ratio of indoor to outdoor concentration was 6.2, 1.9, 3.2, and 3.2 for bacteria, fungi, endotoxins, and dust in the LF industry, 5.0, 0.9, 2.3, and 12.5 in the MWFs industry, and 3.7, 4.1, 3.3, and 9.7 in sawmills. The respiratory fractions of bioaerosols were differentiated by bioaerosol types and industry types: the respiratory fraction of bacteria in the LF industry, MWF industry, and sawmills was 59.4%, 72.0%, and 57.7%, respectively, and that of fungi was 77.3%, 89.5%, and 83.7% in the same order. CONCLUSION: We found that bioaerosol concentration was the highest in sawmills, followed by LF industry facilities and MWFs industry facilities. The indoor/outdoor ratio of microorganisms was larger than 1 and respiratory fraction of microorganisms was more than 50% of the total microorganism concentrations which might penetrate respiratory tract easily. All these findings suggest that bioaerosol in the surveyed industries should be controlled to prevent worker respiratory diseases.
Bacteria ; Biological Agents ; Dust ; Endotoxins ; Fungi ; Gelatin ; Handling (Psychology) ; Livestock ; Polycarboxylate Cement ; Respiratory System

Cardiopulmonary bypass (CPB) is widely used for cardiac surgery by virtue of its proven safety over the course of its use during the past half century. Even though perfusion is safer, incidents still occur. During the repair of a ventricular-septal defect in an 11-month-old infant, we experienced a critical incident related to the potential hazardous effect of volatile anesthetics on the polycarbonate connector of extra-corporeal circuit. The damage to the polycarbonate connector had occurred after spillage of isoflurane during the filling of the vaporizer, causing it to crack and leak. The incident was managed by replacement of the cracked connector during a temporary circulatory arrest. The patient was hypothermic and the time off bypass was less than 1.5 min. There were no neurologic sequelae, the patient made an uneventful recovery. In conclusion, the spillage of volatile anesthetics can cause cracks in the polycarbonate connector of the extra-corporeal circuit, leading to potentially interruption of CPB.
Anesthetics ; Cardiopulmonary Bypass ; Humans ; Infant ; Isoflurane ; Nebulizers and Vaporizers ; Perfusion ; Polycarboxylate Cement ; Thoracic Surgery ; Virtues

Recently, dialysis population with arteriovenous fistula may have some problems about the cannulation due to aged, incompetent vessels. Thus alternative needling method, buttonhole technique has been suggested for the complicated cannulation route. In spite of various benefits, this technique is difficult to apply in Korean hemodialysis unit because it requires much time to form the buttonhole track or tunnel. Meanwhile, Choi et al. reported the superiority of buttonhole technique using the polycarbonate peg, Biohole(TM). Here, we review the buttonhole technique in hemodialysis including new buttonhole technique using the Biohole(TM).
Aged ; Arteriovenous Fistula ; Catheterization ; Dialysis ; Humans ; Polycarboxylate Cement ; Renal Dialysis ; Track and Field

PURPOSE: To evaluate the sealing performance of Hybrid Coat and its influence on the shear bond strength of five dentin surface cements. MATERIALS AND METHODS: Six premolars were pretreated to expose the dentin surface prior to the application of Hybrid Coat. The microscopic characteristics of the dentinal surfaces were examined with scanning electron microscopy (SEM). Then, 40 premolars were sectioned longitudinally, and 80 semi-sections were divided into a control group (untreated) and a study group (treated by Hybrid Coat). Alloy restoration was bonded to the teeth specimen using five different cements. Shear bond strength was measured by the universal testing machine. The fracture patterns and the adhesive interface were observed using astereomicroscope. RESULTS: SEM revealed that the lumens of dentinal tubules were completely occluded by Hybrid Coat. The Hybrid Coat significantly improved the shear bond strength of resin-modified glass ionomer cement (RMGIC) and resin cement (RC) but weakened the performance of zinc phosphate cement (ZPC), zinc polycarboxylate cement (ZPCC) and glass ionomer cement (GIC). CONCLUSION: Hybrid Coat is an effective dentinal tubule sealant, and therefore its combined use with resin or resin-modified glass ionomer cements can be applied for the prostheses attachment purpose.
Adhesives ; Alloys ; Bicuspid ; Dentin ; Glass Ionomer Cements ; In Vitro Techniques* ; Microscopy, Electron, Scanning ; Polycarboxylate Cement ; Prostheses and Implants ; Resin Cements ; Tooth ; Zinc Phosphate Cement