Self-adhesive Resin Cement Research Articles

Aesthetic and functional rehabilitation in a patient with anterior skeletal open bite using lithium dissilicate glass-reinforced ceramic: a case report

The aim of this clinical report is to present the replacement of unsatisfactory metal-ceramic crowns of elements 12, 11, 21 and 22, by lithium disilicate glass-reinforced ceramic crowns in a patient with skeletal anterior open bite. A patient sought care at the Dental Hospital at the School of Dentistry of UFU, complaining of odor between the metal-ceramic crowns of the antero-superior teeth. After clinical and radiographic examination, invasion of the biological space was noticed, surgery was indicated in order to restore the biological space. After healing, the pre-existing cast metal posts were masked using an opaque composite resin and the teeth were reprepared for full all-ceramic crowns. Impressions were taken in two steps, using PVS associated to retraction cords. The ceramic copings were obtained in lithium disilicate ceramic, and the veneering was performed by stratification. After testing the ceramics crowns in relation to, fit, function and aesthetic results, cementation was completed using modified absolute isolation, followed by prophylaxis of preparations with pumice and saline, surface treatment of the ceramic restorations and luting using self-adhesive resin cement. Finally, an occlusal splint was produced to control the effects of bruxism and orofacial pain symptoms. The anterior open skeletal bite was a challenging factor for the rehabilitation of this patient; however, one must consider the entire process that the patient would undergo if choosing for orthognathic surgery, and the patient should be aware of the case limitations. In addition, the use of lithium disilicate glass-reinforced ceramics proved the versatility of this material for anterior aesthetic restorations.

Effect of etch-and-rinse and self-etch modes in universal adhesives on push-out bond strength of fiber post.

BackgroundNowadays, the universal adhesive become more popular among clinicians due to its simple procedure. The application of universal adhesive on root canal dentin prior the self-adhesive resin cement may increase bond-strength between fiber post and dentin. The objective of this study was to evaluate the effect of different etching modes (etch-and-rinse and self-etch) to universal adhesives on push-out bond strength of fiber post. Material and MethodsThirty extracted sound human lower premolars were randomly divided into three groups based on adhesives systems prior to fiber post cementation; two-step etch-and-rinse (group A, Adper Scotchbond), etch-and-rinse universal (group B, Prime & Bond Universal), and self-etch universal (group C, Prime & Bond Universal). After adhesive application, self-adhesive resin cement was filled to the prepared root canal (Smart CEM2, Dentsply) for fiber post cementation. The adhesion between the fiber post and root canal walls was investigated using push-out test after 24 h water storage at 37◦C and the modes of failure were determined under SEM. Data were analyzed using two-way ANOVA test and the Bonferroni test was used to compare values among the three adhesives groups, followed by Tukey HSD for multiple comparisons. Furthermore, Weibull parameters were calculated for tested groups. Results Universal adhesive with self-etch mode significantly improved bond-strength compared to the two-step etch-and-rinse group (p<0.05). The coronal part has higher bond strength than the apical section (p<0.05). However, the bond-strength in two-step etch-and-rinse and etch-and-rinse universal was not significantly different. Self-etch mode showed higher bond strength compared to etch-and-rinse universal adhesive in the apical root section (p<0.05). SEM revealed that all tested groups predominantly had an adhesive failure (p>0.05). ConclusionsSelf-etch mode in universal adhesive system were effectively improved the push-out bond strength of fiber post to root canal dentin, especially in apical root section. Key words:Push-out bond-strength, self-adhesive resin cement, self-etch adhesive, total-etch.

Influence of inorganic composition and filler particle morphology on the mechanical properties of self-adhesive resin cements.

ObjectivesThis study aimed to evaluate the influence of inorganic composition and filler particle morphology on the mechanical properties of different self-adhesive resin cements (SARCs).Materials and MethodsThree SARCs including RelyX Unicem-2 (RUN), Maxcem Elite (MAX), and Calibra Universal (CAL) were tested. Rectangular bar-shaped specimens were prepared for flexural strength (FS) and flexural modulus (FM) and determined by a 3-point bending test. The Knoop microhardness (KHN) and top/bottom microhardness ratio (%KHN) were conducted on the top and bottom faces of disc-shaped samples. Sorption (Wsp) and solubility (Wsl) were evaluated after 24 hours of water immersion. Filler morphology was analyzed by scanning electron microscopy and X-ray energy dispersive spectroscopy (EDS). FS, FM, %KHN, Wsp, Wsl, and EDS results were submitted to 1-way analysis of variance and Tukey’s post-hoc test, and KHN also to paired t-test (α = 0.05).ResultsSARC-CAL presented the highest FS value, and SARC-RUN presented the highest FM. SARC-MAX and RUN showed the lowest Wsp and Wsl values. KHN values decreased from top to bottom and the SARCs did not differ statistically. Also, all resin cements presented carbon, aluminum, and silica in their composition. SARC-MAX and RUN showed irregular and splintered particles while CAL presented small and regular size particles.ConclusionsA higher mechanical strength can be achieved by a reduced spread in grit size and the filler morphology can influence the KHN, as well as photoinitiators in the composition. Wsp and Wsl can be correlated with ions diffusion of inorganic particles.

Influence of Glass Fiber Post Design and Luting Cements on Ease of Post Removal and Fracture Strength of Endodontically Retreated Teeth: An In Vitro Study.

ABSTRACTAims and Objectives:The aim of this study was to evaluate the time needed to remove two types of glass fiber posts cemented with two different cements and removed with two different techniques and to evaluate the fracture strength of teeth after post removal.Materials and Methods:Root canal treatment was completed in 80 extracted single-rooted premolars and the teeth were decoronated. Following canal preparation, the roots were coated with polysiloxane impression material and embedded in acrylic resin cubes. The specimens were randomly divided into eight experimental groups (n = 10) based on the type of fiber post inserted: Reforpost (R) or Contec Blanco (C); luting cement: Multilink-N/self-etch (M) or G-Cem/self-adhesive (G); technique of removal: Peeso reamer (P); or ultrasonic (U). The posts were removed with respective technique under magnification and the time (in seconds) of post removal was determined. Following post removal, the fracture strength of the specimens was determined using a universal testing machine. The mode of failure was also determined. Data were analyzed by three-way analysis of variance (ANOVA), one-way ANOVA, Tukey’s post hoc test, t test, and correlation. Chi-square analysis was performed to compare the failure mode. Statistical significance was set at P < 0.05.Results:The post and cement types had an influence in post removal time (P < 0.05). There was no role of post or cement types on the fracture strength of teeth after post removal with either technique (P > 0.05). A weak negative correlation was found between the post removal time and fracture resistance for both Peeso reamer (r = –0.373) and ultrasonic (r = –0.177) techniques. Both techniques of post removal produced a majority of favorable failures (P > 0.05).Conclusion:The type of post and luting cement plays a significant role in ease of post removal by Peeso reamer or ultrasonic technique. Post-removal technique had no effect on the fracture strength of teeth. Parallel serrated fiber post luted with self-etch resin cements was difficult to remove as compared with parallel smooth surface post luted with self-etch or self-adhesive resin cement.

O4 - Silane Containing Universal Adhesive/Cement for Bonding to Silica-Coated High-Translucent Zirconia

The aim of this study was to evaluate the bonding performance of high-translucent zirconia when pretreated with glass beads and the efficiency of silane contained in self-adhesive resin cement and universal adhesive as chemical treatment for silica-coated high-translucent zirconia. 240 fully sintered disk-shaped zirconia specimens (Y-PSZ, Zpex smile, Tosoh, Japan) were assigned to 4 groups according to mechanical surface pretreatment: alumina particles abrasion with 0.2 MPa pressure (AB2), tribochemical silica-coating with 0.2 MPa (TSC), and glass beads air-abrasion with 0.2 MPa (GB2) and 0.4 MPa (GB4). Each group was cemented with Panavia SA Universal (SAU), Rely X Ceramic Primer (3 M ESPE) + Panavia SA plus (Kuraray Noritake Dental) (S-SAP), and Clearfil Universal Bond Quick + SAP (U-SAP). Tensile bond strength (TBS) was measured at crosshead speed of 2 mm/min after 24 h or 10000 thermocycling (TC) followed by the failure modes analysis (n=10). Surface morphology and surface elemental composition of the abraded zirconia surface analyses were examined under SEM/EDS. Survival analysis was done for TBS data (p = 0.05). After TC, there was a significant decrease in bond strength all groups except TSC and GB4 treated with S-SAP. S-SAP showed highest TBS with TSC, GB2, and GB4. AB2 indicated the highest TBS with U-SAP. SAU showed higher TBS with GB4 compared to GB2. GB4 represented the highest Si content compared to TSC and GB2. Sailanization of glass beads air-abraded zirconia ceramic is mandatory step for successful adhesion to resin cement. Silane containing self-etch adhesive cement was more effective than universal adhesive for glass beads treated zirconia especially with higher air-pressure, but both are less efficient than pure silane treatment. While universal adhesive is efficient pretreatment on tribochemical silica-coating surface and the most effective on alumina-blasted zirconia ceramic.

Effect of intraradicular reinforcement strategies on the fracture strength of endodontically treated anterior teeth with overflared canals.

BackgroundThis study is done to evaluate the effect of different reinforcement techniques of overflared root canals with fiber posts on the fracture resistance of endodontically treated anterior teeth. It also introduces a new technique for simultaneous reinforcement and cementation of fiber posts using dual-cured core build-up composite resin. Material and MethodsThe crowns of 48 single-rooted maxillary anterior teeth were cut and randomly divided into 4 groups (n=12) based on root reinforcement techniques after root canal treatment and post space preparation: Group 1: self-adhesive resin cement (SARC), Group2: dual-cure composite resin (DCC), Group3: Composite resin reinforcement (CRR), Group 4: Direct anatomical post (DAP). Then a core was made for the roots. The periodontal ligament was simulated using a thin layer of PVC impression material. A universal testing machine applied a compressive force to the lingual surface at an angle of 135 ° and 1 mm/min speed. Data were analyzed using One-Way ANOVA and a post-hoc Tukey test. Fracture patterns were analyzed using the Chi-square test (p<0.05). ResultsThe difference between the control and DAP group was statistically significant (p=0.01), but there were no significant differences between other groups (p>0.05). Regarding fracture patterns, there were no significant differences between groups. ConclusionsAll reinforcement techniques increased the fracture strength compared to the control group. However, DAP was the only group that had a statistically significant difference. CRR and DCC presented intermediate values without significant differences. Key words:Fiber post, endodontically treated teeth, root canals, reinforcement, fracture strength.

A method for intracerebroventricular cannulation of young broiler chicks

The site-specific administration of neuroactive substances or pharmacological agents is a routine practice in neurological studies. To facilitate chronic treatments intercranial cannulae are often implanted in the skull. These surgical procedures are widely described and well-documented for rodents, as the most common animal model, and even refined over the years. However, precise descriptions of proper procedure for third ventricle cannulation in young broiler chicks is not readily available. This absence is surprising, as chicken models are often used in the investigation of physiological control of the metabolism and ingestion. Furthermore, as a commercial animal, there is also a particular interest in elucidating the central regulation of feed intake and metabolism to optimize feeding and living conditions for broilers. The brain nuclei that serve as the regulatory centers of feeding and metabolism are the arcuate nucleus, the ventromedial hypothalamic nucleus, and the lateral hypothalamus, which are all located near the third ventricle. Here, we provide a full protocol for intracerebroventricular (i.c.v.) cannulation of 7-day old broiler chicks, as well as a review of some of the advances made in rodent i.c.v. cannulations and whether these advances are applicable to cannulations in chickens. Using the surgical procedure described here, we were able to achieve a success rate of proper implantation of 88%, with a mortality rate of less than 1% (n = 224).•Detailed procedure for i.c.v. canula implantation in the third ventricle of 7d-old broiler chicks.•Cement cap with anchoring screws is necessary in broilers, glue does not provide sufficient stability.•Carboxylate cement and self-adhesive resin cement were tested as an alternative for methyl methacrylate cement.

Cytotoxicity of two self-adhesive resin cements and their interference in the phagocytic activity of murine macrophages.

ObjectivesThis study aimed to evaluate in vitro the effects of the self-adhesive resin cements RelyX U200 (3M ESPE) and seT PP (SDI Limited) on murine macrophages and the interference of the photoactivation.Materials and MethodsCell viability assays, cell adherence, yeast phagocytosis of Saccharomyces boulardii and production of reactive oxygen species (ROS) were performed in the presence of capillaries containing the respective self-adhesive cement when photoactivated or not.ResultsAfter long periods of contact, both types of cements, when not photoactivated, are more cytotoxic for macrophages. The seT PP cement when only chemically activated seems to interfere more negatively in the process of phagocytosis of yeasts S. boulardii. Both types of cements interfere in the cell adhesion process, independent of photoactivation. None of the types of cements tested was able to induce the production of ROS.ConclusionsOur results highlight the great importance of the photoactivation of self-adhesive resin cements in the dental clinic, since RelyX U200, when photoactivated, presented the best results within the evaluated parameters.

Clinical assessment of two inlay-retained bridge designs in missing posterior teeth cases: a Randomized Clinical Trial

Objective: This study aimed to evaluate the clinical performance of two inlay-retained bridge designs (proximalshaped and inlay shaped) in single missing posterior teeth cases. Material and Methods: A total of 70 caseswith missing single posterior teeth were included in this study and divided into two groups with a 1:1 allocationratio (n = 35 for each group). Group 1 (the control group): this group received an inlay retained bridge withinlay design on both abutments. Group 2 (the intervention group): this group received an inlay retained bridgewith a proximal box on both abutments. PMMA resin (YAMAHACHI PMMA) was used for the try-in stage andmonolithic zirconia (Katana, Kuraray) was used for the final restorations. The restoration surfaces were treatedusing sandblasting and Z-prime S (Bisco) and the cementation was done by using self-adhesive resin cement(Bisco). Fracture, marginal adaptation, postoperative sensitivity, caries, and gingivitis were assessed using themodified United States Public Health Service for restoration clinical assessments (MUSPHS standards) over 12months of follow-up. Results: The results show there was no significant difference between the two groups.Kaplan-Meier survival curve was constructed to calculate the mean survival estimates of the two groups and wefound that the two groups were clinically successful during a one-year follow-up. Conclusion: Both designs ofinlay retained fixed dental prostheses revealed successful clinical performance in terms of Fracture, marginaladaptation, postoperative sensitivity, caries, and gingivitis.KEYWORDSFracture; Inlay-retained fixed dental prosthesis; PMMA; Resin cement; Zirconia.

Comparison of Shear Bond Strength of Three Luting Materials Used in Band and Loop Space Maintainer Cementation: An In Vitro Study

Introduction: Aim of this study is to compare shear bond strength of different luting materials used in fixed space maintainer cementation. Methods: Thirty intact extracted human third molars randomly divided into three equal groups: group A: RelyX luting 2 (resin modified glass ionomer); group B: TOTALCEM (self-adhesive resin cement/ dual cure); group C: Transbond plus (compomer). After bonding procedures, the samples were kept in distilled water at 37°C for 24 hours prior to the shear bond strength test. Data were analyzed blindly by one-way ANOVA test and the Tukey post hoc test using R software. Results: There were statistically significant differences between the three luting materials (P < 0.001). Conclusion: TOTALCEM showed significantly higher shear bond strength than RelyX luting 2 and Transbond plus. With respect to limitations of in vitro studies, long-term clinical studies required.

Mandibular overdenture retained with precision balls and bar attachment

Introduction. Milled precision bar with the lateral additions of two precision attachments could significantly contribute to the primary and secondary retention of partial denture and overdenture. This clinical case demonstrates stability of mandibular overdenture using milled precision bar and two coronally positioned precision attachments. Case report. A sixty-five years old male patient had two preserved canine roots in lower jaw. Semicircular metal-ceramic (PFM) bridge was previously fabricated for upper teeth. Decision for fabrication of milled bar and metal framework of overdenture was established due to the presence of PFM bridge in the upper jaw. The root canals of the two remaining mandibular canines were prepared for posts. After final mandibular impression using A-silicone in a custom tray, master cast with prepared canals of roots of canines was provided. Two posts connected with milled precision bar were designed. Coronal attachments-patrixs were positioned onto the tip of each coronal part of the construction with axial direction of precision attachments towards root canals. The construction was invested and casted. Metal framework of overdenture was designed and casted. After interocclusal record, the artificial anatomic teeth were selected and waxed model of overdenture with matrixes was provided for try-in clinical phase. Finally, the overdenture was flasked and polished. Metal construction of two posts and milled bar were cemented simultaneously with overdenture, using self-adhesive resin cement. Conclusion. Milled bar improves retention and stability of metal framework of overdenture. Coronally positioned patrix of attachment provides redirection of occlusal and other functional forces towards apical root parts.

Bond strength of self-adhesive resin cement to dentin using different adhesion protocols.

BackgroundThe treatment of dentin before the use of self-adhesive cements is still a crucial point to achieve the best bond strength values. The objective of this study was to evaluate the bond strength between dentin and composite resin using different adhesion strategies with self-adhesive resin cement. Material and MethodsForty healthy third human molars were randomly divided into 4 groups (n = 10): CA (control); application of self-adhesive cement (Rely X U200, 3M ESPE), AD + CA: only application of conventional adhesive (Adper Single Bond 2, 3M ESPE) + self-adhesive cement, AC + AD + CA; conditioning with 37% phosphoric acid for 15 seconds + application of conventional adhesive + self-adhesive cement and AC + CA; conditioning with 37% phosphoric acid for 15s + self-adhesive cement. Blocks made of composite resin (Z250 XT, 3M ESPE) were cemented over dentin. The samples were stored for 24h in distilled water at 37ºC and then were sectioned on a metallographic cutter to obtain tooth picks with approximately 1.0 mm2 in cross section. A universal testing machine was used with a speed of 0.5 mm/min to test the microtensile bond strength,. The fracture patterns were classified as adhesive, cohesive and mixed failures. The data (MPa) were analyzed statistically by One-way ANOVA and Holm-Sidak test (α=5%). ResultsThe AC + AD + CA and AC + CA groups had the highest averages, while the CA and AD + CA groups had the lowest bond strength values. Adhesive failure was prevalent in all groups. ConclusionsConditioning with 37% phosphoric acid for 15s increases the adhesion of the self-adhesive resin cement to the dentin, regardless of the use of dental adhesive system. Key words:Resin cement, microtensile bond strength, acid conditioning.

Cytotoxicity Comparison of a Calcium Silicate-Based Resin Cement versus Conventional Self-Adhesive Resin Cement and a Resin-Modified Glass Ionomer: Cell Viability Analysis

Objective: To compare the cytotoxicity level of a new calcium silicate-based resin cement (TheraCem) with two commonly used cements, including a conventional self-adhesive resin cement (Panavia SA) and a resinmodified glass ionomer cement (FujiCem2), on the human gingival fibroblast cells after 24 and 48 hours. Material and Methods: Twelve discs of each cement type were fabricated. The extract of cement disks was made by incubating them in the cell medium. Human gingival fibroblast cells were cultured and exposed to cement extracts for 24 h and 48 h. MTT assay was performed on extracts and optical density and cell viability rates were calculated by the spectrophotometer device at 570 nm. Data were analyzed using ANOVA and Tukey HSD tests. Results: The cell viability rates after 24 hours and 48 hours were as follows: TheraCem: 89.24% and 85.46%, Panavia SA: 49.51% and 46.57% and FujiCem2: 50.63% and 47.36%. TheraCem represented the highest cell viability rate. However, no significant difference was noted between Panavia SA and FujiCem2. Time had no significant effect on cell viability. Conclusion: TheraCem exhibited the best results among three tested cements and was considered non-toxic. Panavia SA and FujiCem2 were not significantly different regarding the cell viability rate. Time had no significant effect on the cytotoxicity level of cements.

Effect of ultraviolet light irradiation time on the shear bond strength of self-adhesive resin cement to prosthetic materials

Effect of ultraviolet light irradiation time on the shear bond strength of self-adhesive resin cement to prosthetic materials

Effect of dentin surface pretreatment with four conditioning agents on micro-shear bond strength of a self-adhesive cement

BackgroundTo evaluate the effect of dentin surface pretreatment with four conditioning agents on the micro-shear strength of a self-adhesive cement. Material and Methods32 specimens of 6 mm high x 4 mm wide with dentin exposure were obtained and divided into four groups of NaOCI, CHX, EDTA and AgNPs (n = 8). 2 mL of each treatment agent was applied to the dentin for 60 seconds. Composite resin cylinders measuring 3 mm x 2 mm were cemented with RelyX U200 self-adhesive cement. Micro-shear testing was performed after 24 hours and one week (n = 4) with a 1 mm/min; failure values were recorded in MPa. The failure pattern was evaluated with a stereomicroscope at 20x. The Kruskal-Wallis test was used to evaluate differences between groups. The Mann-Whitney U test was used to evaluate between evaluation times. The significance level used was p<0.05. ResultsAt 24 hours after cementation, the highest value of micro-shear bond strength was observed for chlorhexidine (15.951 MPa), this value were similar for NaOCl 4% and EDTA, however significant differences were observed when compared with AgNPs (p<0.05). When compared the values at 24 hours and after one week, no differences were observed (p>0.05). The most frequent failure pattern was mixed, followed by adhesive failure. ConclusionsPretreatment of dentin with sodium hypochlorite, CHX and EDTA positively affected the 24-hour bonding capacity of RelyX U200 self-adhesive resin cement, although it decreased after one week. Key words:Dental cements, disinfectants, calcium chelators, nanoparticles.

Effect of accelerated aging on color stability of dual-cured self-adhesive resin cements and light-cured resin cement

Effect of accelerated aging on color stability of dual-cured self-adhesive resin cements and light-cured resin cement

Evaluation of the shear bond strength of zirconia to a self-adhesive resin cement after different surface treatment.

The aim of this study was to evaluate the SBS of pre-sintered and sintered zirconia to a selfadhesive resin cement after various treatment (air abrasion and the Nd:YAG laser irradiation at varying power levels -1 W, 2 W and 3 W). Ninety-nine zirconia specimens were prepared and divided into 3 groups: control (with no surface treatment); and pre-sintered and sintered groups with surface treatment. Surface treatment was applied before sintering in the pre-sintered group and after sintering in the sintered group. After following all protocols, a resin cement was layered on the zirconia surface. Shear bond strength was measured using a universal testing machine. The results were subjected to the statistical analysis. The surface topography and phase transformation of zirconia were evaluated using the atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses after surface treatment. The laser irradiation (3 W, 1 W and 2 W) of the pre-sintered zirconia surface resulted in the highest SBS values (p < 0.001), while the lowest SBS values were obtained with airborne particle abrasion of the pre-sintered and sintered zirconia surfaces. Laser irradiation increased the SBS of pre-sintered zirconia to a resin cement. Surface treatment with air abrasion had a lesser effect on the SBS values.

FRACTURE RESISTANCE UNDER CYCLIC LOADING OF LITHIUM DISILICATE VONLAYS VERSUS ROSETTA VONLAYS RESTORING PREMOLARS (IN VITRO STUDY)

The aim of the study was to assess fracture resistance under cyclic loading of Rosetta®SM CAD vs. IPS e.max CAD (control) vonlays restoring maxillary premolars. According to the sample size calculation, a total of 20 samples will be selected and then divided into two equal groups; 10 sample each based on the material type: Group (A): Ten vonlays (n=10) manufactured from IPS e. max CAD blocks (control). Group ( B): Ten vonlays (n=10) manufactured from Rosetta®SM CAD blocks (intervention). A natural tooth presenting an upper first premolar was prepared in accordance with the ceramic onlay restorations preparation guidelines with an occlusal box with half of the bucco-lingual distance and a 2 mm depth from the cusp tip to pulpal floor, gingival seat with 1 mm depth from pulpal floor, occlusal reduction of 2 mm of the functional cusp with extending the preparation at the palatal surface by 2 mm in the cervical direction, occlusal reduction of 1.5 mm of non-functional cusp and 12º divergence angle. The preparation was then extended to the labial surface, with a 0.5 mm chamfer finish line. All line angles were finally rounded, and all margins were finished. For duplication of the natural tooth; the epoxy dies were constructed. Base and catalyst of the epoxy resin material were mixed as instructed by the manufacturer at a rate of 200r/min and then was poured into the silicon mould under vibration to eliminate any air voids, then was allowed to set completely following the manufacturer instructions for 24 hours, this procedure was repeated 20 times for creating 20 epoxy resin dies which replicating the prepared natural tooth. The die was then scanned by optical scanning using Medit i500 oral scanner. Milling of Vonlays was achieved using Sirona MCX5 milling machine using IPS e. max CAD blocks and Rosetta SM CAD blocks: 10 IPS e.max CAD blocks with block size C14 and 10 Rosetta®SM CAD blocks with block size C14 were used. Vonlays were then seated on their corresponding dies and cemented with dual cured self-adhesive resin cement (Variolink, Ivoclar Vivadent). Cementation procedures were performed by keeping each sample under a constant pressure of 5Kg using a custom designed cementation device for standardization the applied load during cementation process. All samples were mechanically aged (cyclic loading) to simulate 6 months of clinical use. Following that, all samples were subjected to fracture resistance testing under a compressive load to the center of their long axis using computer controlled universal testing machine with a load cell of 5 Kilo newton (K N) with a computer software used for data recording (Instron® Bluehill Lite Software). The mean values ± SDs values for e.max group were (502.39 ±102.89 N) with minimum value (338.16 N) and maximum value (721.29 N). The mean values ± SDs values. Rosetta group were (468.76 ± 67.54 N) with minimum value (367.11 N) and maximum value (648.48 N). Failure modes were determined under stereomicroscope and classified into repairable and catastrophic in both groups and showed that 60% of e.max group exhibited repairable failure while 40% of specimens showed catastrophic failure while in Rosetta group, 90% of the specimens exhibited repairable failure. Only 10% displayed catastrophic failure. Then a fractured part within each group was examined under scanning electron microscope (SEM) to reveal and compare their microstructure.

Bond strength of self-adhesive resin cements to a high transparency zirconia crown and dentin

Background/purposeThe bond strength and durability of highly translucent zirconia ceramics to dentin is still unclear. The purpose of this study was to investigate the effect of various surface treatments on the bond strength of self-adhesive resin cements to high-translucent zirconia crowns and dentin. Materials and methodsA high-transparent zirconia and three self-adhesive resin cements (G-CEM LinkAce (GCL), RelyX U200 (RXU) and TotalCem (TTC)) were used. The zirconia surface was sandblasted with 50 μm alumina particles or coated with an SR Link primer, while a dentin primer (Tetric N-Bond Universal, TBU) was applied to the surface of the dentin. By using three self-adhesive resin cements, zirconia samples were bonded to the dentin surfaces of human teeth. The shear strength of the specimens was measured before and after 10,000-cycle thermocycling or 90-day aging. ResultsWhen using GCL to bond with the untreated dentin and various zirconia surfaces, the shear bond strength of the sandblasted (ZSB) and RS Link primer-coated (ZLK) groups was significantly higher than that of the untreated control group (Zc). However, in the case of TBU-treated dentin, the shear strength of the ZSB + LK + DTBU group was significantly higher than that of the other groups. After thermocycling and aging, the shear strength of the ZSB + LK + DTBU group using GCL and RXU cements decreased slightly, while the TTC showed no impact. ConclusionThe zirconia surface pretreated by sandblasting and bonding agent, which was sequentially bonded with a primer-treated dentin by using resin cements, can provide excellent shear bond strength and anti-aging performance.

Shear bond strengths of two newly marketed self-adhesive resin cements to different substrates: A light and scanning electron microscopy evaluation.

The purpose of this in vitro study was to compare the shear bond strengths (SBSs) of two newly marketed self-adhesive resin cements (RCs) to enamel, dentin, and lithium disilicate (LiSi) glass ceramic block. Forty-eight enamel and 48 dentin substrates were obtained from sound human molars. Additionally, 6 × 7 × 5 -mm- sized 24 specimens were produced from LiSi glass ceramic blocks. The tooth specimens were randomly assigned into four groups (n= 12) according to the surface treatments: (1) G-CEM ONE (GCO), (2) G-CEM ONE Adhesive Enhancing Primer (GCO-AEP) + GCO, (3) RelyX Universal (RXU), and (4) Scotchbond Universal Plus (SUP) + RXU. LiSi specimens were randomly divided into two groups (n= 12): (1) G-MultiPrimer (GMP) + GCO and (2) SUP + RXU. Following the RC applications, all specimens were kept in 100% humidity at 37°C for 24 hr and then submitted for SBS testing in a universal testing machine (1 mm/min). Data were analyzed by Welch's, one-way analysis of variance and two independent samples t tests. The nature of failures was examined under a light microscope, and scanning electron microscopy analyses were also performed for interfaces. GCO and RXU showed similar SBS to enamel (p> .05), and the use of adhesives resulted in improved SBS (p< .05). No difference was detected between GCO-AEP + GCO and SUP + RXU. The GCO-AEP + GCO exhibited the highest SBS to dentin (p< .05), followed by GCO ≥ SUP + RXU > RXU (p< .05). There was no significant difference between SBSs of two RCs to LiSi blocks (p> .05). No cohesive failure was determined for the tested groups by light microscope. The use of adhesives prior to the application of self-adhesive RCs improved their bonding to tooth tissues. GCO demonstrated superior SBS to dentin, whereas both self-adhesive RCs generated similar SBS to enamel and LiSi glass ceramic surfaces.