• The Journal of Advanced Prosthodontics
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• v.10 no.3
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• pp.205-210
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• 2018

PURPOSE. The purpose of this study was to evaluate the efficiency of a gas-phase fluorination method under different fluorination periods through using two resin cements. MATERIALS AND METHODS. 84 zirconia specimens in dimensions of $5mm{\times}5mm{\times}2mm$ were prepared and surface treated with $50{\mu}m$ aluminum oxide particles or gas phase fluorination for 2 min, 5 min, or 10 min. One specimen in each group was surface analyzed under scanning electron microscope. The remaining specimens were bonded to composite cylinders in dimensions of 2 mm diameter and 3 mm high with Panavia SA Plus or Variolink N. Then, the specimens were stored in $37^{\circ}C$ distilled water for 24 hours and shear bond strength test was applied at a speed of 1 mm/min. RESULTS. The highest shear bond strength values were observed in the samples fluorinated for 5 minutes and cemented with Panavia SA Plus. Variolink N did not elicit any statistical differences between surface treatments. Panavia SA Plus resin cement and Variolink N resin cements featured statistically significant difference in shear bond strength values only in the case of 5 minutes of fluorination treatment. CONCLUSION. According to the results of this study, application of 5 minutes of fluorination with 10-methacryloyloxydecyl dihydrogen phosphate monomer (MDP) containing Panavia SA Plus resin cement increased the resin bond strength of zirconia. Fluorination of the zirconia surface using conventional resin cement, Variolink N, did not lead to an increase in bond strength.

• Journal of the Korean Ceramic Society
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• v.56 no.4
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• pp.403-411
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• 2019

In this work, the hydration process and cytotoxicity of lab-synthesized experimental Portland cements (EPCs) were investigated for dental applications. For this purpose, EPCs were prepared using laboratory-synthesized clinker constituents, tricalcium silicate (C₃S), dicalcium silicate (C₂S), and tricalcium aluminate (C₃A). C-A was prepared by the Pechini method, whereas C₃S and C₂S were synthesized by solid-state reactions. The phase compositions were characterized by X-ray diffraction (XRD) analysis, and the hydration process of the individual constituents and their combinations, with and without the addition of gypsum, was investigated by electrochemical impedance spectroscopy (EIS). Furthermore, four EPC compositions were prepared using the lab-synthesized C-A, C₃S, and C₂S, and their hydration processes were examined by EIS, and their cytotoxicity to HPC and HIPC cells were tested by performing an XTT assay. None of the EPCs exhibited any significant cytotoxicity for 7 days, and no significant difference was observed in the cell viabilities of ProRoot MTA and EPCs. The results indicated that all the EPCs are sufficiently biocompatible with human dental pulp cells and can be potential substitutes for commercial dental cements.

• The Journal of Korean Academy of Prosthodontics
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• v.20 no.1
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• pp.25-32
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• 1982

An in vitro study was conducted to compare the bond strength of cements between Verabond coping and various cores. Fifty-four idential cores simulating maxillary central incisor prepared for PFM crowns were made. Eighteen samples were made with 20K cast gold, eighteen with Verabond, and eighteen with Adaptic. Samples were randomly divided into three groups, each consisting of six 20K cast gold, six verabond, and six Adaptic samples. The first group was cemented with zinc phosphate cement, the second group with poly-carboxylate cement, and the third group with glass ionomer cement. Constant finger pressure was applied for cementation. The sample were then stored at $37^{\circ}C$ in distilled water bath for 24 hours. The tensile strength test was performed on an Instron Universal test machine with crosshead speed of 0.05cm/min and the results compared statistically. Results of the study showed that: 1. A significant difference of bond strength was observed with different types of dental cements and core materials. 2. With gold core, zinc phosphate cement was stronger than both the polycarboxylate cement and glass ionomer cement, which did not differ in bond strength. 3. With base-metal core, zinc phosphate cement showed the highest bond strength and was followed by polycarboxylate cement and glass ionomer cement. 4. With composite resin core, zinc phosphate cement showed the highest bond strength and was followed by glass ionomer cement and polycarboxylate cement. 5. The base-metal core (Verabond core) privided the highest retention of all core materials.

• Restorative Dentistry and Endodontics
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• v.22 no.1
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• pp.132-143
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• 1997

Recently composite resin luting cement have been widely used according as esthetic requirement was increased. The purpose of this study was to evaluate of shear bond strength of four resin cements to bovine dentin. The materials used in this study were All-Bond 2(dentin bonding agent), Duolink cement, Bistite resin cement, Twinlook cement, Clearfil CR inlay cement. A total 40 acrylic cylinders with bovine dentin were divided into four groups. Four experimental groups were as follows; Group l(AB) : Specimens bonded with All-Bond 2 and Duolink Cement Group 2(BT) : Specimens bonded with Bistite Resin Cement Group 3(TL) : Specimens bonded with Twinlook Cement Group 4(CR) : Specimens bonded with Clearfil CR Inlay Cement Mter 1 hour of bonding, all specimens were stored for 24 hours in water at $37^{\circ}C$ and tested with Instron universal testing machine between bovine dentin and resin cements. The data were evaluated statistically at the 95% confidence level with a one-way analysis of variance and Tukey's range statistics. The following results obtained; 1. The group l(AB) was highest shear bond strength and the group 3(TL) was 10west(p>0.05). 2. Group 2(BT), 4(CR) were similar shear bond strength and there was no significant difference(p<0.05). 3. Group 1(AB), 4(CR) with acid etching were showed resin tags on the opened dentinal tubules, but Group 2(BT), 3(TL) without acid etching were not showed resin tags. 4. Group l(AB) was showed intimate adaptation than other groups.

• The Journal of Korean Academy of Prosthodontics
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• v.37 no.4
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• pp.465-473
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• 1999

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 few subgroups of 10 for luting cements selected for this study: zinc phosphate cement (FLECK' S), polycarboxylate cement (Poly-F), rein-forced 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.

• The Journal of Advanced Prosthodontics
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• v.8 no.4
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• pp.251-258
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• 2016

PURPOSE. This study was undertaken to investigate whether use of an adhesive penetration enhancer, dimethyl sulfoxide (DMSO), improves bond stability of fiber posts to root dentin using two two-step etch-and-rinse resin cements. MATERIALS AND METHODS. Forty human maxillary central incisor roots were randomly divided into 4 groups after endodontic treatment and post space preparation, based on the fiber post/cement used with and without DMSO pretreatment. Acid-etched root dentin was treated with 5% DMSO aqueous solution for 60 seconds or with distilled water (control) prior to the application of Excite DSC/Variolink II or One-Step Plus/Duolink for post cementation. After micro-slicing the bonded root dentin, push-out bond strength (P-OBS) test was performed immediately or after 1-year of water storage in each group. Data were analyzed using three-way ANOVA and Student's t-test (${\alpha}$=.05). RESULTS. A significant effect of time, DMSO treatment, and treatment${\times}$time interaction were observed (P<.001). DMSO did not affect immediate bonding of the two cements. Aging significantly reduced P-OBS in control groups (P<.001), while in DMSO-treated groups, no difference in P-OBS was observed after aging (P>.05). CONCLUSION. DMSO-wet bonding might be a beneficial method in preserving the stability of resin-dentin bond strength over time when fiber post is cemented with the tested etch-and-rinse adhesive cements.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.3
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• pp.231-242
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• 2006

Statement of problem: The sealing of the opened dentinal tubules that follows the tooth preparation for the prosthodontic restoration is considered as clinical process to reduce postoperative sensitivity. Purpose: This study investigated the effect of desensitization treatment on shear bond strength of luting cements. Materials and Method: Total 80 dentin specimens were divided into two groups according to the kinds of luting cements. Each groups was further divided into 4 subgroups with AQ $bond^{(R)}$, $Saforide^{(R)}$, Diode laser $MDL-10^{(R)}$ application and without desensitization treatment. After desensitization treatment application, Ni-Cr specimens were luted to dentin surface with Fuji $CEM^{(R)}$ and $Panavia-F^{(R)}$. Specimens were placed in distilled water at $37^{\circ}C$ for 24 hours and shear bond strength between metal and dentin was measured by a universal testing machine. Results: 1. In Fuji $CEM^{(R)}$ cemented groups, the combination of AQ $bond^{(R)}$ showed the greatest strength, followed by diode laser, no desensitizer treatment, and $Saforide^{(R)}$. Both AQ $bond^{(R)}$ and Diode laser groups had a significant difference than no desensitization treatment group and $Saforide^{(R)}$ group(p<0.05). 2. In $Panavia-F^{(R)}$ cemented groups, the combination of Diode laser showed the greatest strength, followed by AQ $bond^{(R)}$, $Saforide^{(R)}$, and No desensitization treatment. All desensitization treatment groups had a significant difference than no desensitization treatment group(p<0.05). 3. All $Panavia-F^{(R)}$ groups showed a significant higher shear bond strength than all Fuji $CEM^{(R)}$ groups(p<0.05). Conclusion: The results of this study showed possibility of bond strength increase after desensitization treatment. The application of desensitization treatments like AQ $bond^{(R)}$, $Saforide^{(R)}$, and Diode laser $MDL-10^{(R)}$ have advantages in exposed dentin surface after tooth prep.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.1
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• pp.1-12
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• 2009

The objective of this study was to test the effects of crown material, cement type, the direction in which stress is applied and distribution of luting cement that might lead to cement microfracture using 2D Finite Element Method. Twenty three finite element models with a chamfer margin configuration were generated for a mandibular first molar. Crown models exhibited four crown materials: type 3 gold alloy, Ni-Cr alloy, ceramic and composite resin, and two luting cements: zinc phosphate and glass ionomer cements with a thicknesses of $70{\mu}m$. Modeled crowns were loaded axially or obliquely at unit load of 1 N. Areas and levels of stress concentrations within the cement were determined. Stress in the cement layer at the margins of crowns were higher than those in the area away from the margin. Stress under oblique loads were much higher than under axial load. The stiffer crown material produced higher stress and similarly, higher stress were found in cements with the greater Young's modulus.

• Restorative Dentistry and Endodontics
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• v.41 no.4
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• pp.278-282
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• 2016

Objectives: Glass ionomer cements (GICs), which are biocompatible and adhesive to the tooth surface, are widely used nowadays for tooth restoration. They inhibit the demineralization and promote the remineralization of the tooth structure adjacent to the restoration, as well as interfere with bacterial growth. Hence, the present study was conducted to assess and compare the antimicrobial activity of three commercially available GICs against two cariogenic bacteria. Materials and Methods: An agar plate diffusion test was used for evaluating the antimicrobial effect of three different GICs (Fuji IX, Ketac Molar, and d-tech) on Streptococcus mutans (S. mutans) and Lactobacillus acidophilus (L. acidophilus). Thirty plates were prepared and divided into two groups. The first group was inoculated with S. mutans, and the second group was inoculated with L. acidophilus. These plates were then incubated at $37^{\circ}C$ for 24 hours. Zones of bacterial growth inhibition that formed around each well were recorded in millimeters (mm). Results: The zones of inhibition for Fuji IX, Ketac Molar, and d-tech on S. mutans were found to be $10.84{\pm}0.22mm$, $10.23{\pm}0.15mm$, and $15.65{\pm}0.31mm$, respectively, whereas those for L. acidophilus were found to be $10.43{\pm}0.12mm$, $10.16{\pm}0.11mm$, and $15.57{\pm}0.13mm$, respectively. Conclusions: D-tech cement performed better in terms of the zone of bacterial inhibition against the two test bacteria, than the other two tested glass ionomers.

• The Journal of Korean Academy of Prosthodontics
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• v.41 no.3
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• pp.379-386
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• 2003

Statement of problem. Resin cements are widely used in adhesive dentistry specially on all ceramic restorations. It is needed to find out adequate bonding strength between different porcelain surface treatments, commercially available porcelains, and different resin cement systems. Purpose. The purpose of this study was to evaluate shear bond strength of resin cements bonded to porcelains in three different modalities; 5 different porcelain surface treatments, 3 different resin cement systems and 3 different commercially available pressable porcelains. Material and Method. This study consisted of 3 parts. Part I examined the effect of five different surface treatments on the pressable porcelain. Fifty discs (5 mm in diameter and 3 mm in height) of Authentic porcelain were randomly divided into 5 groups (n = 10). The specimens were sanded with 320 grit SiC paper followed by 600 grit SiC paper. The specimens were treated as follow: Group 1-Sandblasting (aluminum oxide) only, Group 2 - sandblasting/ silane, Group 3 - sandblasting/ acid etching/ silane, Group 4 - acid etching only, Group 5 - acid etching/ silane. Part II examined the shear bond strength of 3 different resin cement systems (Duolink, Variolink II, Rely X ARC) on acid etching/ silane treated Authentic pressable porcelain. Part 3 examined the shear bond strength of Duolink resin cement on 3 different pressable porcelains (Authentic, Empress I, Finesse). All cemented specimens were stored in distilled water for 2 hours and tested with Ultradent shear bond strength test jig under Universal Instron machine until fracture. An analysis of variance(ANOVA) test was used to evaluate differences in shear bond strength. Result. The shear bond strength test resulted in the following: (1) Acid etched porcelains recorded greater shear bond strength values to the sandblasted porcelains. (2) Silane treated porcelains recorded greater shear bond strength values to non-silane treated porcelains. (3) There was no significant difference between sandblasting/ acid etching/ silane treated and acid etching/ silane treated porcelains. However those values were much higher than other three groups. (4) The shear bond strength with Variolink II was lower than the value of Duolink or Rely X ARC. (5) The shear bond strength of Finesse was lower than the value of Authentic or Empress I.