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

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: 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

PURPOSE: The objective of this study was to evaluate the influence of various cement types on the stress distribution in monolithic zirconia crowns under maximum bite force using the finite element analysis. MATERIALS AND METHODS: The models of the prepared #46 crown (deep chamfer margin) were scanned and solid models composed of the monolithic zirconia crown, cement layer, and prepared tooth were produced using the computer-aided design technology and were subsequently translated into 3-dimensional finite element models. Four models were prepared according to different cement types (zinc phosphate, polycarboxylate, glass ionomer, and resin). A load of 700 N was applied vertically on the crowns (8 loading points). Maximum principal stress was determined. RESULTS: Zinc phosphate cement had a greater stress concentration in the cement layer, while polycarboxylate cement had a greater stress concentration on the distal surface of the monolithic zirconia crown and abutment tooth. Resin cement and glass ionomer cement showed similar patterns, but resin cement showed a lower stress distribution on the lingual and mesial surface of the cement layer. CONCLUSION: The test results indicate that the use of different luting agents that have various elastic moduli has an impact on the stress distribution of the monolithic zirconia crowns, cement layers, and abutment tooth. Resin cement is recommended for the luting agent of the monolithic zirconia crowns.
Bite Force ; Computer-Aided Design ; Crowns* ; Dental Cements ; Dental Stress Analysis ; Finite Element Analysis* ; Glass ; Glass Ionomer Cements ; Polycarboxylate Cement ; Resin Cements ; Tooth ; Zinc Phosphate Cement ; Zirconium

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

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

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

PURPOSE: Major drawbacks of conventional bone marrow stromal cells (BSCs) transplantation method are mainly caused by direct transplanted cell to host cell interactions. We hypothesized that separation of the transplanted cells by a microporous membrane might inhibit most of the potential adverse effects and induce superior effect. The purpose of the study is to determine the optimal condition of the microporous membrane. METHODS: First, BSCs were placed in polyethylene terephthalate (PET) transwell inserts with 3, 8, or 12 micrometer pore size, and cultured in 24 well culture plates. After 5 days, bottoms of the plates were observed for presence of attached BSCs in monolayer and cell numbers were evaluated. Second, BSCs were placed PET, polycarbonate (PCT), and mixed cellulose esters (MCE) transwell inserts with 3 and 8 micrometer pore size, and cultured in 24 well culture plates. After 3 days, the supernatants of the media left in culture plate were analyzed for collagen, vascular endothelial growth factor (VEGF), platelet derived growth factor BB (PDGF-BB), and basic fibroblast growth factor (bFGF). Third, BSCs were placed in 15% and 70% of the PET membrane with 3 micrometer pore size. All the experimental conditions and methods were same as the second study. RESULTS: The optimal pore sizes to prevent BSC leakage were 3 micrometer and 8 micrometer. The amounts of type I collagen and three growth factors tested did not show significant differences among PET, PCT, and MCE groups. However, the collagen, VEGF, and bFGF levels were much higher in the high (70%) density group than in the low (15%) density group. CONCLUSION: This study revealed that the optimal pore size of membrane to prevent direct BSC to recipient cell contact is in between 3 micrometer and 8 micrometer. Membrane materials and pore sizes do not influence the collagen and growth factor passage through the membrane. The most striking factor for collagen and growth factor transport is pore density of the membrane.
Bone Marrow ; Cell Communication ; Cell Count ; Cellulose ; Collagen ; Collagen Type I ; Esters ; Fibroblast Growth Factor 2 ; Intercellular Signaling Peptides and Proteins ; Membranes ; Mesenchymal Stromal Cells ; Phthalic Acids ; Platelet-Derived Growth Factor ; Polycarboxylate Cement ; Polyethylene Terephthalates ; Strikes, Employee ; Transplants ; Vascular Endothelial Growth Factor A ; Wound Healing

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

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