Self-adhesive Resin Cement RelyX Unicem Research Articles

Effect of tribochemical silica coating or multipurpose products on bonding performance of a CAD/CAM resin-based material

ObjectivesNanocomposite ceramics have been widely used in clinical practice; however, a standard, recommended bonding protocol has not been determined yet. The present study aimed to evaluate application of tribochemical silica coating or multipurpose products on bonding performance of a CAD/CAM resin-based material (known as nanocomposite ceramic). Materials and methodsNanocomposite ceramic specimens were fabricated and assigned into 11 groups to build bonded specimens (n = 15) according to surface treatments (none; air particle abrasion with 50-μm alumina followed by application of a silane coupling agent or a universal adhesive; tribochemical silica coating followed by application of a silane coupling agent or a universal adhesive) and resin luting cements (conventional resin cement, RelyX Veneer; self-adhesive resin cement RelyX Unicem) used. Micro-shear bond strength (μ-SBS) was measured after 24-h water storage or ageing with 10,000 thermocycles plus additional 90-d water storage. Surface roughness after alumina air abrasion and tribochemical silica coating were determined using a profilometer. Surface morphology and element variation were observed by using a scanning electron microscope (SEM)/energy dispersion spectrum (EDS). X-ray photoelectron spectroscopy (XPS) was used to characterize nanocomposite ceramic powders conditioned with silane coupling agent or the universal adhesive used in the μ-SBS test. The nanocomposite ceramic plates received alumina air abrasion, tribochemical silica coating, or without, were determined using X-ray diffraction (XRD). ResultsNanocomposite ceramic treated with alumina air abrasion achieved the highest surface roughness, followed by those treated with tribochemical silica coating. Newly formed Si–O–Si bonds on the nanocomposite ceramic surface were detected by XPS after treatment with silane coupling agent or universal adhesive, and a Zr–O–P bond was detected after treating with universal adhesive. μ-SBS was significantly affected by bond strategies and ageing. Ageing by thermocycling and water storage significantly decreased μ-SBS. μ-SBS values derived by use of a universal adhesive or self-adhesive resin cement alone were no lower than the values derived by use of a silane coupling agent alone. Pre-silanization further enhanced the bonding improvement of universal adhesive or self-adhesive resin cement. However, tribochemical silica coating failed to provide higher μ-SBS compared with alumina air abrasion. XRD detected no monoclinic zirconia phase after alumina air abrasion or tribochemical silica coating, suggesting that these two roughening methods did not lead to phase transformation of zirconia fillers. ConclusionsCombination of presilanization and universal adhesives improve resin bonding of nanocomposite ceramics. Tribochemical silica coating is not superior to alumina air abrasion for pretreated nanocomposite ceramics.

SHEAR BOND STRENGTH OF DIFFERENT ADHESIVE RESIN CEMENTS TO DENTIN

Objective: This study investigated the shear bond strength SBS of different adhesive resin cements [self-adhesive resin cement RelyX Unicem(RXU), adhesive resin cement with self-etch adhesive RelyX Ultimate with Single bond Universal adhesive (RXUT) and adhesive resin cement that utilize etch and rinse technique RelyX ARC with Single bond2 adhesive (ARC)] to dentin. Methods: Sixty extracted molars embedded in epoxy resin were prepared by sectioning the buccal surface to expose flat Buccal dentin and were ground with 400-grit SiC paper. The samples were divided into 3 groups (N=20) based on the adhesive resin cements used. Sixty composite discs 3mm in diameter Z 350 (3M ESPE)) were constructed & bonded to the prepared dentin surfaces according to manufacturer instructions. For each group half the samples were thermo-cycled (TC) between 5-55˚C for 2500 cycles and then all samples were tested using a universal testing machine using chisel blade. The results were statistically analyzed using Mann-Whitney &Wilcoxon Signed Ranks tests.Results: The mean SBS (± standard deviation) were: 6.95±1.5 MPa for RXU, 0 for RXU(TC), 22.58±5.45 for RXUT, 15.20±3.98 for RXUT (TC), 25.9±5.3 for ARC, and 19.5±4.3 for ARC(TC). RXU had significant lower bond strength than both RXUT &ARC (P 0.05).Conclusions: (1) The self-adhesive resin cement (RXU) had significant lower bond strength to dentin than that of RXUT & ARC. (2) No significant difference was found between the used adhesive resin cements that utilized self-etch adhesive and that utilized etch & rinse adhesive.

Influence of root dentin treatment on the push-out bond strength of fiber posts.

The aim of the present study was to assess whether different dentin conditioning protocols with different acids [phosphoric acid, ethylene diamine tetra acetic acid (EDTA), and polyacrylic acid (PAA)] influence the bond strength of fiber posts along the radicular depth when luted with self-adhesive resin cement. Twenty single-rooted teeth were randomly divided into four experimental groups (n=5) according to dentin treatment: Group 1: no treatment; Group 2: etching with 35% phosphoric acid for 10s; Group 3: 17% EDTA application for 60s; and Group 4: conditioning with 25% PAA for 30s. RelyX Fiber Posts were luted with the self-adhesive resin cement RelyX Unicem 2 Automix (3M ESPE). Roots were transversally sectioned into nine 1-mm thick specimens, three corresponding to each root third and a push-out test was performed. Data were analyzed by two-way ANOVA and Tukey test (p<0.05). Failure mode was determined and specimens with representative failures for each group were observed under scanning electron microscopy. According to the results, dentin treatment influenced the bond strength (p<0.001), whereas the root third did not (p>0.05). Fiber posts luted after treating dentin with phosphoric acid, and PAA exhibited the highest push-out bond strength values, while the lowest were obtained after EDTA application. Intermediate results were obtained when dentin was not conditioned. In conclusion, the bond strength of the self-adhesive resin cement RelyX Unicem 2 improves when root dentin is treated with 35% phosphoric acid or 25% PAA, before fiber posts luting irrespective of the root depth.

Fracture Resistance of Molar Crowns Fabricated with Monolithic All-Ceramic CAD/CAM Materials Cemented on Titanium Abutments: An In Vitro Study.

To assess the fracture resistance of single-tooth implant-supported crown restorations made with different CAD/CAM blocks. Thirty-six titanium abutments were put on dental implant analogs (Mis Implant). For each of three test groups (n = 12/group), implant-supported, cement-retained mandibular molar single crowns were produced. Crowns were made of lithium disilicate glass (LD) IPS e.max CAD, feldspathic glass ceramic (FEL) Vita Mark II, and resin nano-ceramic (RNC) Lava Ultimate. The crowns were cemented with self-adhesive resin cement RelyX Unicem 2. After chewingcycling, crowns were tested to failure in a universal testing machine. Fracture values were calculated as initial (F-initial) and maximum fracture (F-max). The study groups were ranked, in order of having highest value, (LD > FEL) > RNC for F-initial load value and (LD > RNC) > FEL for F-max load value. This demonstrated that there was no parallel change in the F-initial and F-max values presenting the fracture resistance of specimens. There was no accordance between the F-initial and F-max values of the LD, RNC, and FEL after chewing simulation with thermocycling resembling 5 years of clinical functional use. LD had the highest fracture resistance during the fracture test. RNC had low fracture resistance; however, it had considerably high fracture resistance during the fracture test. FEL had considerably low fracture resistance values.

Do resin cements influence the cuspal deflection of teeth restored with composite resin inlays?

The aim of this study was to evaluate the influence of different resin cements on the cuspal deflection of endodontically treated teeth restored with composite resin inlays. Sixty upper premolars were randomly divided into five groups (n=12): 1 - sound teeth; 2 - cavity; 3 - Rely X ARC; 4 - RelyX Unicem; 5 - SeT. The teeth from groups 2, 3, 4 and 5 received a MOD preparation and endodontic treatment. Impressions were made with vinyl polysiloxane and poured using type IV die stone in groups 3, 4 and 5. Inlays with composite resin were built over each cast and luted with the resin cements. A 200 N load was applied on the occlusal surface, and cuspal deflection was measured using a micrometer. After 24 h, cuspal deflection was measured again using a 300 N load. The Student t-test showed that there was no statistically significant difference between the 200 N and 300 N occlusal loads only for the sound teeth group (p = 0.389) and the RelyX ARC group (p = 0.188). ANOVA and Tukey'test showed that the sound teeth had the lowest mean cuspal deflection, differing statistically from the other groups (p<0.05). The highest cuspal deflections were obtained in the SeT group and the cavity group, with no statistical difference between them. Intermediate values were obtained in RelyX ARC group and RelyX Unicem group, which differed statistically. The self-adhesive resin cements RelyX Unicem and SeT showed less capacity to maintain the stiffness of the tooth/restoration complex than the conventional resin cement RelyX ARC.

Effect of cementation protocol on push-out bond strength of fiber posts to root canal

Abstract The aim of this study was to evaluate the effect of adhesive protocol on the retention of glass-fiber posts luted into root canals. Thirty bovine incisors were endodontically treated and 9-mm-deep post holes were prepared. Fiber posts were luted using one of following protocols (n = 10): SB – Single Bond (3 M ESPE) with regular resin cement RelyX ARC (3 M ESPE); SBMP – Scotchbond Multipurpose Plus (3 M ESPE) associated with RelyX ARC; or UNI – the self-adhesive resin cement RelyX Unicem (3 M ESPE). After cementation, root/post specimens were transversally sectioned into 1-mm-thick slices, which were submitted to push-out testing in a mechanical testing machine. Bond strength data were analyzed by ANOVA (α = 0.05). There was no statistical difference between the adhesive protocols evaluated. Considering that the adhesive protocols evaluated showed similar bond strength values, simpler protocols must be preferable to lute fiber posts to root canal.

Leucite-reinforced glass ceramic inlays luted with self-adhesive resin cement: A 2-year in vivo study

ObjectivesAim of the present prospective controlled clinical study was to compare the clinical performances of two different cementation procedures to lute IPS Empress inlays and onlays. MethodsEighty-three IPS Empress restorations (70 class-II inlays, 13 onlays/47 premolars, 36 molars) were placed in 30 patients (19 females/11 males, mean age=39 years). Two cementation procedures were tested: group 1: forty-three restorations were luted with a self-adhesive resin cement (RelyX Unicem, RX, 3M ESPE); group 2: forty restorations were luted with an etch-and-rinse multistep adhesive (Syntac Classic, Ivoclar-Vivadent) and Variolink II low (SV, Ivoclar-Vivadent). All restorations were evaluated after 2 weeks (baseline=1st recall=R1, n=83), 6 months (R2, n=83), 1 year (R3, n=82), and 2 years (R4, n=82) by two independent blinded calibrated examiners using modified USPHS criteria. ResultsFrom R1 to R4, one failure occurred in the SV group (at R2) due to marginal enamel chipping. After 2 years of clinical service (R4), better marginal and tooth integrity (p<0.05) was found in group 2 (SV) compared to the use of the self-adhesive cement (RX, group 1), while no differences were found for all remaining investigated criteria (p>0.05). The absence of enamel in proximal boxes (10% with no enamel and 51% of the restorations with less than 0.5mm enamel width at the bottom of the proximal box) did not affect marginal performance (p>0.05). SignificanceThe self-adhesive resin cement RelyX Unicem showed clinical outcomes similar to a conventional multi-step cementation procedure after 2 years of clinical service for most of the tested criteria.

Evaluation of bond strength of self-adhesive cements to dentin with or without application of adhesive systems.

To evaluate the bond strength of indirect restorations to dentin using self-adhesive cements with and without the application of adhesive systems. Seventy-two bovine incisors were used, in which the buccal surfaces were ground down to expose an area of dentin measuring a minimum of 4 x 4 mm. The indirect resin composite Resilab was used to make 72 blocks, which were cemented onto the dentin surface of the teeth and divided into 4 groups (n = 18): group 1: self-adhesive resin cement BiFix SE, applied according to manufacturer's recommendations; group 2: self-adhesive resin cement RelyX Unicem, used according to manufacturer's recommendations; group 3: etch-and-rinse Solobond M adhesive system + BiFix SE; group 4: etch-and-rinse Single Bond 2 adhesive system + RelyX Unicem. The specimens were sectioned into sticks and subjected to microtensile testing in a universal testing machine (EMIC DL- 200 MF). Data were subjected to one-way ANOVA and Tukey's test (α = 5%). The mean values (± standard deviation) obtained for the groups were: group 1: 15.28 (± 8.17)a, group 2: 14.60 (± 5.21)a, group 3: 39.20 (± 9.98)c, group 4: 27.59 (± 6.57)b. Different letters indicate significant differences (ANOVA; p = 0.0000). The application of adhesive systems before self-adhesive cements significantly increased the bond strength to dentin. In group 2, RelyX Unicem associated with the adhesive system Single Bond 2 showed significantly lower mean tensile bond strengths than group 3 (BiFix SE associated with the etch-and-rinse Solobond M adhesive system).

Controlled, prospective, randomized, clinical evaluation of partial ceramic crowns inserted with RelyX Unicem with or without selective enamel etching. Results after 2 years

Among the materials used for luting indirect restorations, growing interest has been directed towards the use of self-adhesive resin cements. The aim of this prospective randomized controlled clinical trial was to evaluate the clinical performance of the self-adhesive resin cement RelyX Unicem (RXU) for luting partial ceramic crowns (PCCs). In addition, the influence of selective enamel etching prior to luting (RXU+E) was assessed. Two-year results are reported. Thirty-four patients (68 PCCs) had originally received the intended treatment at baseline (BL). Twenty-nine patients (14 male, 15 female) with a total of 58 PCCs participated in the 2-year recall. In each patient, one PCC had been placed with RXU, one PCC with RXU+E. Restorations were evaluated at BL and 24months after placement using modified United States Public Health Service criteria for postoperative hypersensitivity, anatomic form, marginal adaptation, marginal discoloration, surface texture and recurrent caries. Additionally, the "percentage failure" within the 2-year recall period for all restorations (n = 68) was calculated according to ADA Program Guidelines. Target value for acceptability of each procedure was <5% failure within 24m. For statistical analysis of the data, the chi-square test was applied (α = 0.05). The median patient age was 41years (24-59years). Median PBI was 8% (5-10%). Twenty-two RXU PCCs were placed in molars, seven in premolars. Twenty-one RXU+E PCCs were placed in molars, eight in premolars. Statistically significant changes were observed for marginal adaptation (MA) and marginal discoloration (MD) between BL and 2years but not between the two groups (RXU, RXU+E). Percentage of alfa values at BL for MA (RXU, 97% and RXU+E, 100%) and for MD (RXU, 97% and RXU+E, 97%) decreased to RXU, 14% and RXU+E, 28% for MA and to RXU, 50% and RXU+E, 59% for MD after 24months. Within the observation period, three failures were recorded with RXU (5.1% failure), one failure was recorded for RXU+E (1.7% failure), but a significant influence of selective enamel etching on failure could not be verified. Although the results of the present study reveal a slight tendency for more favourable results if selective enamel etching is applied prior to insertion of ceramic PCCs with a self-adhesive luting material, longer-term evaluation is needed to confirm this. Additional selective enamel etching with a self-adhesive luting material does not considerably improve clinical performance of the restorations within the observation period reported, neither does it impose a hazard with respect to postoperative hypersensitivity.

Nanoleakage of luting agents for bonding fiber posts after thermomechanical fatigue.

To investigate the depth of nanoleakage of four luting agents for bonding fiber posts after thermomechanical fatigue. Twenty-four extracted human anterior teeth were endodontically treated, sectioned at the cementoenamel junction, and restored with fiber posts using four commercially available resin cements with the corresponding core buildup materials (n = 6): Panavia F 2.0/Clearfil DC Core Automix (Kuraray), Variolink II/Multicore Flow (Ivoclar Vivadent), RelyX Unicem/Filtek Z250 (3M ESPE), and Multilink Sprint/Multicore Flow (Ivoclar Vivadent). The specimens received all-ceramic crowns and were subjected to thermomechanical fatigue (1.2 million cycles). After cutting off the crowns, the roots were isolated with nail polish except for a 1-mm rim around the root canal, and immersed in 50 wt% ammoniacal silver nitrate solution for 24 h. The specimens were sectioned perpendicular to the long axis of the tooth into four slices, fixed, dehydrated, and processed for FE-SEM. Leakage was analyzed using backscattered FE-SEM and EDS. The depth of nanoleakage was significantly affected by the factor resin cement (p < 0.015; Kruskall-Wallis). Multilink Sprint resulted in significantly deeper penetration of silver particles than the other materials (p < 0.05; Mann Whitney U-Test). Hybridization of the root canal dentin created by self-etching or etch-and-rinse adhesive systems demonstrated distinctive nanoleakage up to 0.8 mm, whereas the self-adhesive resin cement RelyX Unicem was able to prevent distinctive leakage at this penetration depth. However, none of the investigated luting systems would be able to hermetically seal the root canal if leakage occurred around the margins of the coronal restoration.

Comparison of Bond Stability Between Dual-Cure Resin Cements and Pretreated Glass-Infiltrated Alumina Ceramics

To evaluate the bond stability of resin cements used for luting alumina-based all-ceramic dental restorations. Although different pretreatments may be applied on alumina to improve bond strengths, any previous study investigated the bond stability of resin-based cements luted to laser-irradiated alumina. 64 sintered, glass-infiltrated alumina blocks were sandblasted and randomly assigned to the following subgroups: 1. no additional treatment (NT); 2. Rocatec (Roc); 3. Nd:YAG laser (L); and 4. Nd:YAG laser plus Rocatec (LRoc). Composite samples were bonded to conditioned ceramics using two different resin based cements: a self-etching adhesive cement-Panavia F (PF) and a self-adhesive resin cement-RelyX Unicem (RXU). After 24 h, bonded specimens were cut into microtensile sticks (1 ± 0.1 mm(2)). One-half of the beams were loaded in tension until failure. The remaining one-half was immersed in 10%-NaOCl aqueous solution (NaOCl(aq)) for 12 h before testing. ANOVA and Student-Newman-Keuls tests were run (P < 0.05). Failure mode was recorded. Ceramic topography was SEM-analyzed. After 24 h, L-sticks achieved the highest MTBS despite the cement type, whereas NT-samples recorded the lowest values. After NaOCl(aq) immersion bond strengths decreased except for RXU luted to NT-alumina. PF luted to L- and LRoc-samples, and RXU luted to L-sticks attained the highest bond strength. Nd:YAG laser irradiation improved bond strength between alumina ceramics and resin cements (PF or RXU). Chemical challenging impaired adhesion, mainly through resin matrixes and silane coupling degradation. Laser-treated specimens remained with the highest bond strength.

Bond Strength of Fiber Posts after the Application of Erbium:Yttrium-Aluminum-Garnet Laser Treatment and Gaseous Ozone to the Root Canal

The aim of the present study was to investigate the effects of antibacterial agents (erbium:yttrium-aluminum-garnet [Er:YAG] laser or gaseous ozone) intended to disinfect root canals on bond strengths of fiber posts compared with canals that were finally irrigated using chlorhexidine (CHX). One hundred forty-four human anterior teeth were divided into three groups ( n = 48); root canal instrumentation was performed, and antimicrobial pretreatment was conducted as follows: control group: CHX, group 2: Er:YAG laser, and group 3: gaseous ozone. In all groups, fiber posts were inserted using Panavia F 2.0 (Kuraray, Osaka, Japan), Variolink II (Ivoclar Vivadent, Schaan, Liechtenstein), RelyX Unicem (3M Espe; Seefeld, Germany), or Ketac Cem (3M Espe) ( n = 12 each). Push-out bond strengths to root canal dentin were affected by the type of luting agent but not by the antimicrobial pretreatment regimen. However, significant interactions between the luting agent and pretreatment could be observed, and adhesion of the self-adhesive resin cement RelyX Unicem was significantly reduced after using gaseous ozone.