RelyX Unicem Resin Cement Research Articles

EVALUATION OF SHEAR BOND STRENGTH OF HIGH-PERFORMANCE POLYMERS TO ITS RESIN VENEERING AND TO DENTIN (IN VITRO STUDY)

INTRODUCTION: : Looking through the wide range of prosthetic options High-performance polymers properties. Needs over layering resin veneer, bonded by a special adhesive, this adds an additional challenge to achieve adequate bond strength, also its bonding to tooth structure remains difficult. OBJECTIVES: To evaluate shear bond strength of CAD/CAM High-performance polymers (BioHPP) with its CAD/CAM veneering composite using two different adhesives, as well as to dentin using two types of cements. MATERIALS AND METHODS: This in vitro study, for Group I, twenty BioHPP discs with their CAD/CAM veneering composite, were milled and divided randomly into two subgroups (n =10) according to the adhesive system used. Subgroup IA: using DTK adhesive (dualhardening adhesive). Subgroup IB: using Combo.lign (dual-hardening adhesive). For Group II, twenty CAD/CAM High-performance polymers (BioHPP) discs were milled and divided into two subgroups according to the different cements used to lute to dentin surface. Subgroup IIA: using: RelyX Unicem resin cement, subgroup IIB: using Fuji Plus GI cement. After water storage, thermocycling (1200 cycles, 5°C/55°C) corresponding to one year of clinical service, all the specimens were subjected to shear force until failure and the results in the various groups were compared and statistically analyzed. Modes of failure were assessed. RESULTS: Mean SBS were as follows: subgroup IA (DTK adhesive 6.238), subgroup IB (combo.lign2.42), subgroup IIA (RelyX Unicem 2.07) and subgroup IIB (Fuji Plus 3.77). Mann-Whitney test demonstrated significant differences between the two subgroups in groups I and II (U= 2.0, P=.001) (U=17, P=.013) respectively. Stereomicroscope revealed that mixed and adhesive failure were the most dominant mode of failure. CONCLUSIONS MDP-Containing Self-adhesive Resin (DTK adhesive) is recommended as efficient adhesive to increase the shear bond strength of the veneering composite to BioHPP. Also Fuji Plus showed better bond strength than RelyX Unicem with BioHPP and dentin.

Effect of non-thermal plasma on the shear bond strength of resin cements to Polyetherketoneketone (PEKK).

PURPOSEThis study aimed to assess the effect of non-thermal plasma on the shear bond strength of resin cements to polyetherketoneketone (PEKK) in comparison to other surface treatment methods.MATERIALS AND METHODSEighty PEKK discs were subjected to different surface treatments: (1) Untreated (UT); (2) Non-thermal plasma (NTP); (3) Sandblasting with 50 µm Al2O3 particles (SB); and (4) Sandblasting + Non-thermal plasma (SB+NTP). After each surface treatment, the contact angle was measured. Surface conditioning with Visio.Link was applied in all groups after pre-treatment. RelyX Unicem resin cement was bonded onto the PEKK specimens. After fabrication of the specimens, half of each group (n=10) was initially tested, while the other half was subjected to thermocycling (5℃ to 55℃ at 10,000 cycles). Shear bond strength (SBS) testing was performed using a universal testing machine, and failure modes were assessed using stereomicroscopy. The SBS results were analyzed statistically using one-way ANOVA followed by Tukey's post hoc test. Independent t-test was used to examine the effect of thermocycling (P<.05).RESULTSThe highest SBS values with or without thermocycling were observed with PEKK specimens that were treated with SB+NTP followed by the SB group. The lowest SBS results were observed in the UT groups.CONCLUSIONThe shear bond strength between PEKK and resin cements was improved using non-thermal plasma treatment in combination with sandblasting.

Live cell imaging reveals different modes of cytotoxic action of extracts derived from commonly used luting cements

ObjectiveTo compare cytotoxicity of extracts derived from commonly used luting cements: Hoffmann’s Zinc Phosphate (ZPC), GC Fuji Plus Resin Modified Glass Ionomer (RMGIC) and 3M ESPE RelyX Unicem Resin Cement (RC) on primary human gingival fibroblasts (HGFs). DesignHGFs were exposed to different concentrations of the ZPC, RMGIC and RC extracts. The cytotoxicity was assessed with the PrestoBlue Cell Viability Reagent and viable cells were counted by a haemocytometer using the trypan blue exclusion test. In order to determine the primary mechanism of the cell death induced by extracts from different luting cements, the real-time monitoring of caspase-3/-7 activity and membrane integrity of cells was employed. ResultsThe extracts from the RMGIC and ZPC decreased the metabolic activity and numbers of viable cells. Unexpectedly, the extracts from the RC evoked only small effects on the metabolic activity of HGFs with a decreasing number of viable cells in a dose-and time-dependent manner. The live cell imaging revealed that the apoptosis was the primary mechanism of a cell death induced by the extracts derived from the RMGIC, whereas the extracts from the RC and ZPC induced a cell death through a necrotic and caspase-independent pathway. ConclusionsThe apoptosis was the primary mechanism of the cell death induced by the extracts derived from the RMGIC, whereas the extracts from the RC and ZPC induced a cell death via a necrotic pathway. We suggest that metabolic assays commonly used to assess the cytotoxicity of luting cements should be validated by alternative methods.

Analysis of Self-Adhesive Resin Cement Microshear Bond Strength on Leucite-Reinforced Glass-Ceramic with/without Pure Silane Primer or Universal Adhesive Surface Treatment

Objective. To evaluate the microshear bond strength (μSBS) of self-adhesive resin (SA) cement on leucite-reinforced glass-ceramic using silane or universal adhesive. Materials and Methods. Ceramic blocks were etched with 9.5% hydrofluoric acid and divided into three groups (n = 16): (1) negative control (NC) without treatment; (2) Single Bond Universal (SBU); (3) RelyX Ceramic Primer as positive control (PC). RelyX Unicem resin cement was light-cured, and μSBS was evaluated with/without thermocycling. The μSBS was analyzed using one-way analysis of variance. The fractured surfaces were examined using stereomicroscopy and scanning electron microscopy (SEM). Results. Without thermocycling, μSBS was highest for PC (30.50 MPa ± 3.40), followed by SBU (27.33 MPa ± 2.81) and NC (20.18 MPa ± 2.01) (P < 0.05). Thermocycling significantly reduced μSBS in SBU (22.49 MPa ± 4.11) (P < 0.05), but not in NC (20.68 MPa ± 4.60) and PC (28.77 MPa ± 3.52) (P > 0.05). PC and NC predominantly fractured by cohesive failure within the ceramic and mixed failure, respectively. Conclusion. SBU treatment improves μSBS between SA cement and glass ceramics, but to a lower value than PC, and the improvement is eradicated by thermocycling. NC exhibited the lowest μSBS, which remained unchanged after thermocycling.

Efficacy of surface treatments on the bond strength of resin cements to two brands of zirconia ceramic.

To compare the shear bond strengths (SBS) of two cements to two Y-TZP ceramics subjected to different surface treatments. Zirconia specimens were made from Lava (n = 36) and IPS e.max ZirCAD (n = 36), and their surfaces were treated as follows: no treatment (control), silica coating with 30-µm silica-modified alumina (Al2O3) particles (CoJet Sand), or coating with liners Lava Ceram for Lava and Intensive ZirLiner for IPS e.max ZirCAD. Composite resin cylinders were bonded to zirconia with Panavia F or RelyX Unicem resin cements. All specimens were thermocycled (6000 cycles at 5°C/55°C) and subjected to SBS testing. Data were analyzed by three-way ANOVA and Tukey's (HSD) post-hoc test (α = 0.05). Failure mode was analyzed by stereomicroscope and SEM. CoJet Sand and liners promoted significantly higher SBS than their control groups, but had similar results to one another. Panavia F provided significantly higher SBS values than RelyX Unicem (p < 0.01) for nontreated zirconia specimens of both brands. When Lava and IPS e.max ZirCAD were abraded with CoJet Sand, RelyX Unicem promoted significantly higher SBS values than Panavia F (p < 0.001). There was no significant difference between the two cements when the zirconia specimens were treated with their respective liners. The nontreated specimens and those treated with CoJet Sand exhibited a high percentage of adhesive and mixed A failures, while the specimens treated with liners presented an increase in mixed A and mixed C failures as well as some cohesive failure in the bulk of Lava Ceram for both cements. CoJet Sand and liners provided the best surface treatment for Lava and IPS e.max ZirCAD. The best surface treatment/cement combinations were CoJet Sand/RelyX Unicem and liner/Panavia F. SBS of Panavia F and RelyX Unicem was not influenced by the zirconia brand.

Restoration of Strip Crown with a Resin-Bonded Composite Cement in Early Childhood Caries

Background. Early childhood caries is a widely prevalent disease throughout the world. It is necessary to treat this condition in early childhood; however, child behavior management may be particularly challenging during treatment. To overcome this challenge, we used Carigel to remove caries and RelyX Unicem resin cement for strip crown restoration. It not only has the desired aesthetic effect but is also more effective for primary teeth, which are used for a shorter period than permanent teeth are. Case Presentation. We report a case of three pediatric patients with early childhood caries, in whom caries was removed by using Carigel to avoid the risk of pulpal exposure associated with high-speed handpieces. Subsequently, aesthetic restoration was performed using strip crown with RelyX Unicem self-adhesive resin cement. Conclusion. RelyX Unicem has the following advantages: (1) not requiring have any special skills for the dentist for performing the procedure, (2) decreased occurrence of bubbles during injection of the cement, and (3) overall short duration of the procedure. Thus, it is appropriate for the treatment of pediatric patients whose behavior is difficult to manage. However, further studies are required in order to establish the use of RelyX Unicem as a stable restorative material in early childhood caries.

Resistance against pull-out force of prefabricated coated FRC posts.

To investigate the effect of a prefabricated tribochemical coating of FRC (fiber-reinforced composite) posts with and without aging on the pull-out forces compared to posts without conditioning. Post space preparations were performed on 108 extracted anterior teeth. Thirty-six uncoated FRC posts (DentinPost) and 72 prefabricated tribochemically coated FRC posts (DentinPost Coated) were used at a length of 12 mm. Thirty-six of the coated posts were thermally aged. FRC posts (n = 9) were placed using DentinBuild or MultiCore Flow foundation composite resins or Panavia F2.0 or RelyX Unicem resin cements. Following water storage (37°, 24 h) and thermocycling (5000 cycles, 5° to 55°C, 30 s), pull-out force testing was performed. Fracture modes were assessed using a light microscope. Data were analyzed statistically (1-way and 3-way ANOVA, Bonferroni-Dunn correction, α = 0.05). Significantly higher pull-out forces of posts luted with Panavia F2.0 were observed for the coated and coated/aged FRC posts compared to the unconditioned posts (control group, p < 0.001). The pull-out forces of tribochemically coated FRC posts luted with MultiCore Flow were significantly lower than of coated posts luted with Panavia F2.0 (p < 0.001). Coated/aged FRC posts exhibited similar pull-out forces for the tested luting composite resins (p > 0.05). Except for DentinBuild (coated posts), more mixed or cohesive fractures were assessed for coated and coated/aged FRC posts than for unconditioned FRC posts. Prefabricated tribochemical coating of FRC posts provided a stable interface between coating and post and remained stable over time.

Adhesive bonding of resin cements to cast titanium with adhesive primers

The purpose of this study was to evaluate the effects of adhesive primer applications on the bond strength of resin cements to cast titanium. Four adhesive primers - Metaltite, Metal Primer II, Alloy Primer and Ceramic Primer - and their respective resin cements - Bistite II DC, Link Max, Panavia F 2.0, RelyX Unicem and RelyX ARC - were tested. Cast plates were prepared from titanium ingots (n=6 specimens/cement) and had their surfaces airborne-particle abraded with Al2O3 (50 μ m). Three resin cement cylinders were built on each bonded titanium surface, using a cylindrical translucent tubing mold and were subjected to micro-shear testing. Data were analyzed statistically by two-way ANOVA and Tukey's post-hoc test (α=0.05). The application of Metal Primer II and Ceramic Primer resulted in significant higher bond strength for Link Max and RelyX Unicem resin cements, respectively, than nonuse of adhesive primers. Panavia F 2.0 and RelyX ARC yielded high bond strength means with or without adhesive primers. The use of adhesive primers might increase the bond strength to cast titanium depending on the resin cement used.

Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements

Objectives Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass–ceramic. Methods 210 glass–ceramic discs (12 mm diameter, 0.8 mm thickness) were allocated to seven groups ( n = 30). The bi-axial flexure strength (BFS) was determined for ‘as-fired’ specimens (group A), following HF-acid etching (group B) and following etching and centrally loading on a semi-compliant substrate with 30 N for 300 s (group C). Further etched specimens were coated with Rely-X Unicem resin-cement under cementation loading of 5 or 30 N, for 60 or 300 s (groups D–F) prior to BFS determination using multilayered analytical solutions. BFS data was compared using factorial or one-way analyses of variance and the Weibull analysis. Results HF-acid etching of the ‘as-fired’ surface resulted in a significant reduction in mean BFS ( P < 0.001) whereas resin-cementation subsequently conferred significant strengthening ( P < 0.001) ranging from 24 to 38% and dependent on the loading parameters employed. A factorial significance ( P = 0.004) of seating load (5 or 30 N) and significant factorial interaction ( P < 0.001) of seating load and load duration (60 or 300 s) on the mean BFS were identified. Significance The magnitude of resin-reinforcement conferred was sensitive to the loading parameters investigated although the mechanisms underlying the variation appear complex. Similar patterns of variability can be expected clinically impacting on the clinical longevity of resin-cemented glass–ceramic restorations.

Effect of surface conditioning on the retentive bond strengths of fiberreinforced composite posts

Debonding is a common cause of failure encountered with fiber-reinforced composite (FRC) posts, and usually occurs along the post space-dentin adhesive interface. Surface conditioning of posts is expected to increase the chemical and mechanical bond between the luting composite resin and the post, but the best method has not been definitively determined. The purpose of this in vitro study was to compare the effects of 3 surface-conditioning methods on the retentive bond strengths of FRC posts using 5 composite resin materials, and compare results to those of unconditioned FRC posts as well. Post space preparations (DentinPost ER root post system, length of 12 mm) were performed on 200 human anterior teeth. Groups of 50 FRC posts (ISO size 90) each were treated using 1 of the following conditioning methods: silanization, etching with 5% hydrofluoric acid, tribochemical coating (CoJet system), or were left untreated (control group). FRC posts (n=10) in each group were placed using 1 of 5 composite resin materials (Calibra or RelyX Unicem resin cements or Build-It, MultiCore Flow, or Rebilda DC foundation composite resins). Following water storage (37 degrees C, 24 hours) and thermal cycling (5000 cycles, 5 degrees -55 degrees C, 30-second dwell time), tensile strength testing was performed. Fracture modes were assessed using a light microscope. Data were analyzed statistically (1-way and 2-way ANOVA, Bonferroni-Dunn correction, alpha=.05). Retentive bond strengths of FRC posts luted with MultiCore Flow in combination with the CoJet system, and of posts inserted with Rebilda DC in combination with hydrofluoric acid (HF) etching as well as with the CoJet system, were significantly higher than those of the corresponding unconditioned FRC posts (P<.001). No significant differences were noted between the bond strength values of RelyX Unicem with CoJet, MultiCore Flow with CoJet, and Rebilda DC with either CoJet or HF etching (P>.05). Retentive bond strengths were significantly lower for HF etching (Calibra, RelyX Unicem, Build-It), and for the treatment with the CoJet system in combination with Build-It compared to the corresponding control groups (P<.001). Fracture modes were primarily adhesive at the post surface or cohesive within the composite resin layer or within the FRC post. The retentive bond strengths differed significantly with respect to the tested combinations of conditioning method and luting composite resin.

Effect of luting cement to push-out bond strength of fibre reinforced post

he objective of this study was to investigate the effect of various luting cement systems on bond strength of fibre-reinforced posts to root canal dentine. 40 extracted single rooted sound premolar teeth were root filled, decoronated and randomly divided into four groups. Fibre posts, Aestheti- Plus™ (Bisco,Inc. Schaumburg, IL, USA) were cemented using four luting cements: Group A (control): Elite 100® Zinc phosphate (GC Corp, Japan), Group B: Calibra ™ Esthetic Resin Cement (Dentsply Caulk, USA), Group C: RelyX ARC Adhesive Resin (3M ESPE), Group D: RelyX Unicem Aplicap (3M ESPE). Each root was sliced into 2 discs representing the coronal and middle portions of the root canal giving rise to 20 specimens per group. Bond strength was determined using push-out tests and data was analyzed using SPSS version 14.0. The mean bond strength of Group A to Aestheti-Plus™ post was 7.71 MPa (±2.51) and Group B was 5.69 MPa (±3.23). Group C exhibited the lowest mean bond strength, 4.29 MPa (±3.53) while the highest bond strength was obtained from Group D, 7.98 MPa (±2.61). One way ANOVA showed significant interaction between all groups (p=.OOI). Post-hoc Bonferroni test reve;iled that bond strength of Group C was significantly lower compared to Group A (p=.008) and D (p=.004). In conclusion, the mean bond strength of Aestheti- Plus™ post to root canal dentine was highest when cemented with RelyX Unicem resin cement followed by Elite 100® zinc phosphate cement, Calibra and RelyX ARC resin cements. However, the bond strengths of Cali bra and RelyX Unicem resin cements were not significantly different from Elite 100® zinc phosphate cement.