• The Journal of Advanced Prosthodontics
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• v.10 no.5
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• pp.340-346
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• 2018

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 ($5{\times}5{\times}3mm$) 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 ($1.96{\pm}0.4$) (P<.00), while Au-Pt showed the lowest among all metals tested ($1.57{\pm}0.4$) (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 ($3.59{\pm}0.07$) among all cements tested (P<.00), while the resin-based temporary luting cement RXT showed the lowest ($0.39{\pm}0.07$) (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.

• The Journal of the Korean dental association
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• v.48 no.9
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• pp.680-687
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• 2010

The purpose of this study was to compare post cementation efficacy according to the different adhesive systems and cement delivery methods. A total of 40 extracted human single-rooted premolar teeth were randomly divided in four groups according to the two luting agents of Unicem applicap (3M ESPE, St. Paul, MN, USA) or Variolink II (Ivoclar Vivadent, Liechtenstein) and cement delivery methods of direct cement application or lentulo spiral application. After restoration using glass?fiber posts, the samples were embedded in acrylic resin. Three sections of 2 mm thickness were prepared from each specimen, and the post in each section was subjected to a push-out test. The data were analysed statistically at significant level of 95%. The Unicem had significantly higher push-out bond strength than Variolink and the lentulo spiral application made higher bond strength (p<0.05). Adhesive failure between cement and dentin was predominant in all groups. The Unicem of self-etch system and cement delivery using lentulo spiral showed clinically acceptable and comparable bonding strength for the fiber post.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.4
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• pp.251-258
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• 2010

Purpose: To evaluate the effect of surface conditioning on the shear bond strength of zirconium-oxide ceramic to 4 luting agents. Materials and methods: A total of 120 diskshaped zirconium-oxide ceramic blocks (3Y-TZP, Kyoritsu, Japan) were treated as follows: (1) Sandblasting with $110\;{\mu}m$ aluminum-oxide ($Al_2O_3$) particles; (2) tribochemical silica coating (Rocatec) using $110\;{\mu}m$ $Al_2O_3$ particles modified by silica; (3) no treatment. Then zirconium-oxide ceramic blocks bonded with 4 luting cements (RelyX luting (3M ESPE), Maxcem (Kerr), Nexus3 (Kerr), Rely X Unicem (3M ESPE)). Each group was tested in shear bond strengths by UTM. A 1-way analysis of variance and 2-way analysis of variance was used to analyze the data ($\alpha$ = .05). Results: RelyX unicem in combination tribochemical silica-coating produced a highest bond strength (P < .05). Air abrasion group and Rocatec treatment groups resulted in significantly higher than no conditioning group (P < .05). RelyX Luting groups showed lower bond strength than other groups. There were significant differences among groups (P < .05). Conclusion: Within the limitation of this study, RelyX Unicem cement provided the highest bond strength and Rocatec treatment enhanced the bond strength.

• Journal of Dental Rehabilitation and Applied Science
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• v.27 no.3
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• pp.253-265
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• 2011

When restoring endodontically treated teeth is the mismatch between fiber post size and post space diameter, the resin cement layer is excessively thick in post space and voids are likely to form in it, thus predisposing to de-bonding. The method to overcome this problem is to reline the fiber post with composite resin. This individual anatomic post improves the adaptation of post to root walls and decreases the resin cement thickness. The purpose of this in vivo study was to evaluate the push-out bond strength of fiber post according to relining procedure and luting agents type used for simplicity of clinical procedure. Forty-two extracted teeth were divides into six groups.(n=7) A1: relined fiber post cemented with Luxacore/all-bons 2, A2: non-relined fiber post cemented with Luxacore/all-bond2, B1: relinind fiber post cemented with Calibra/XP-bond, B2: non-relined fiber post cemented with Calibra/XP-bond, C1: relined fiber post cemented with RelyX Unicem, C2: non-relined fiber post cemented with RelyX Unicem Push-out bond strength was affected by interaction between relining procedure and luting agent type. Relined fiber post presented higher push-out bond strength value than non-relined fiber post and statically significant differences(p<0.05) Cementation with RelyX Unicem showed significantly higher bond strength than other luting agents(p<0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.318-324
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• 2015

Purpose: This study compared shear bond strengths of five self-adhesive cements with phosphate monomer to zirconium oxide ceramic with and without airborn particle abrasion. Materials and methods: One hundred zirconia samples were air-abraded ($50{\mu}mAl_2O_3$). One hundred composite resin cylinders were fabricated. Composite cylinders were bonded to the zirconia samples with either Permacem 2.0 (P), $Clearfil^{TM}$ SA Luting (C), $Multilink^{(R)}$ Speed (M), $RelyX^{TM}$ U200 Automix (R), G-Cem $LinkAce^{TM}$ (G). All bonded specimens were stored in distilled water ($37^{\circ}C$) for 24 h and half of them were additionally aged by thermocycling ($5^{\circ}C$, $55^{\circ}C$, 5,000 times). The bonded specimens were loaded in shear force until fracture (1 mm/min) by using Universal Testing Machine (Model 4201, Instron Co, Canton, MA, USA). The failure sites were inspected under field-emission scanning electron microscopy. The data was analyzed with ANOVA, Tukey HSD post-hoc test and paired samples t-test ($\alpha$=.05). Results: Before and after thermocycling, $Multilink^{(R)}$ Speed (M) revealed higher shear-bond strength than the other cements. G-Cem $LinkAce^{TM}$ (G) showed significantly lower bond strengths after thermocycling than before treatment (P<.05), but the other groups were not significantly different (P>.05). Conclusion: Most self-adhesive cements with phosphate monomer showed high shear bond strength with zirconia ceramic and weren't influenced by thermocycling, so they seem to valuable to zirconia ceramic bonding.

• The Journal of Advanced Prosthodontics
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• v.4 no.4
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• pp.192-196
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• 2012

PURPOSE. The purpose of this study was to evaluate the effect of provisional cement removal by different dentin cleaning protocols (dental explorer, pumice, cleaning bur, Er:YAG laser) on the shear bond strength between ceramic and dentin. MATERIALS AND METHODS. In total, 36 caries-free unrestored human third molars were selected as tooth specimens. Provisional restorations were fabricated and cemented with eugenol-free provisional cement. Then, disc-shaped ceramic specimens were fabricated and randomly assigned to four groups of dentin cleaning protocols (n = 9). Group 1 (control): Provisional cements were mechanically removed with a dental explorer. Group 2: The dentin surfaces were treated with a cleaning brush with pumice Group 3: The dentin surfaces were treated with a cleaning bur. Group 4: The provisional cements were removed by an Er:YAG laser. Self-adhesive luting cement was used to bond ceramic discs to dentin surfaces. Shear bond strength (SBS) was measured using a universal testing machine at a 0.05 mm/min crosshead speed. The data were analyzed using a Kolmogorov Smirnov, One-way ANOVA and Tukey HSD tests to perform multiple comparisons (${\alpha}$=0.05). RESULTS. The dentin cleaning methods did not significantly affect the SBS of ceramic discs to dentin as follows: dental explorer, pumice, cleaning bur, and Er:YAG laser. CONCLUSION. The use of different cleaning protocols did not affect the SBS between dentin and ceramic surfaces.

• Restorative Dentistry and Endodontics
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• v.45 no.2
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• pp.19.1-19.8
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• 2020

Objective: This study aimed to evaluate the effect of ultrasonic cleaning of the intracanal post space on the bond strength of fiber posts in oval canals filled with a premixed bioceramic (Bio-C Sealer [BIOC]) root canal sealer. Materials and Methods: Fifty premolars were endodontically prepared and divided into 5 groups (n = 10), based on the type of root canal filling material used and the post space cleaning protocol. A1: gutta-percha + AH Plus (AHP) and post space preparation with ultrasonic cleaning, A2: gutta-percha + BIOC and post space preparation with ultrasonic cleaning, B1: gutta-percha + AHP and post space preparation, B2: gutta-percha + BIOC and post space preparation, C: control group. Fiber posts were cemented with a self-adhesive luting material, and 1 mm thick slices were sectioned from the middle and cervical third to evaluate the remaining filling material microscopically. The samples were subjected to a push-out test to analyze the bond strength of the fiber post, and the results were analyzed with the Shapiro-Wilk, Bonferroni, Kruskal-Wallis, and Mann-Whitney tests (p < 0.05). Failure modes were evaluated using optical microscopy. Results: The results showed that the fiber posts cemented in canals sealed with BIOC had lower bond strength than those sealed with AHP. The ultrasonic cleaning of the post space improved the bond strength of fiber posts in canals sealed with AHP, but not with BIOC. Conclusions: BIOC decreased the bond strength of fiber posts in oval canals, regardless of ultrasonic cleaning.

• The Journal of Korean Academy of Prosthodontics
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• v.53 no.4
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• pp.325-329
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• 2015

Purpose: The aim of this study was to compare the film thicknesses of several resin cements as a function of time after mixing and to examine the effect of working time on the film thicknesses. Materials and methods: The film thickness (${\mu}m$) of 4 resin cements (n=10), 1 composite resin (Panavia F 2.0), 3 self-adhesive resin (Clearfil SA luting, Zirconite, RelyX U200) cements was measured at 20-second intervals after mixing of the cements up to 200 seconds under a load of 50 N. Linear regression was fitted to verify the effect of working time on the film thickness of each cement. Data were compared to the working time recommended by manufacturers using Wilcoxon test ($\alpha$=.05). Results: All of the materials showed a positive linear correlation between the film thickness and working time. There was no statistically significant difference between the working time based on our results and the values recommended by the manufacturers even though there was a discrepancy between those two values. Conclusion: The film thickness of resin cements could increase with the increase of working time. Working time to meet the ISO standard of $50-{\mu}m$ maximum film thickness could be different from the manufacturer's recommended value.