Showing 12 results for Resin Cement
H. Hajimiragha , S. Nokar , Z. Nemati , A. Khajavi ,
Volume 19, Issue 1 (4-2006)
Abstract
Background and Aim: Cementation is one of the most critical steps of the porcelain restoration technique. However, limited information is available concerning the bond strength of current ceramic bonding systems. The aim of this study was to evaluate the shear bond strength of three dual-cure resin cements to IPS-Empress2 ceramics.
Materials and Methods: In this experimental study, 30 pairs of IPS-Empress 2 ceramic discs were fabricated with 10 and 8 mm diameters and 2.5 mm thickness. After sandblasting and ultrasonic cleaning, the surfaces of all specimens were etched with 9% hydrofluoric acid for 60 seconds. Then, the three groups of 10 bonded specimens were prepared ceramic bonding resin systems including Panavia F2, Variolink II and Rely X ARC. After storage in 37±1c water for 24 hours and thermocycling in 5c and 55c water for 500 cycles with 1-minute dwell time, the shear bond strengths were determined using Instron machine at speed of 0.5mm/min. Data were analyzed by One Way ANOVA test. For multiple paired comparisons, the Tukey HSD method was used. The mode of failure was evaluated by scanning electro microscope (SEM). P<0.05 was considered as the limit of significance.
Result: Significant differences were found between different cement types (P<0.05). Variolink II provided the highest bonding values with IPS-Empress2. A combination of different modes of failure was observed.
Conclusion: Based on the results of this study, according to the highest mode of cohesive failure, Variolink II seems to have the strongest bond with IPS-Empress2 ceramics.
M. Ghavam , H. Kermanshah , M. Ataei , N. Shadman ,
Volume 20, Issue 1 (5-2007)
Abstract
Background and Aim: Insufficient polymerization of resin cements is of considerable clinical importance, because of mechanical deficiencies and biological side effects of uncured resin. Dual cure resin cements are getting popular in luting tooth colored posts and although their curing is claimed to proceed chemically, polymerization efficiency in deep areas of canal is uncertain. The aim of this study was to evaluate degree of polymerization of dual-cure resin cements used for luting translucent and opaque fiber posts in different distances from the light tip.
Materials and Methods: In this experimental in vitro study, degree of conversion of two dual cured resin cements, Rely X ARC (3M, ESPE) and Nexus 2 (Kerr, USA) were measured when used with DT-Light and DT-White posts (RTD, France). The light curing unit used was Optilux 501, with output of 650-700 mw/cm2 with emitting time of 60 seconds. Degree of conversion was measured in three different depths (4, 6, 8 mm) by FTIR. The data were analyzed using ANOVA and Post hoc tests. P<0.05 was considered as the level of significance.
Results: DC% of Rely X with either of the posts was not significantly different in the studied depths (P>0.05). Nexus used with DT-Light had lower DC% in 8 mm depth (P<0.05). Nexus used with DT-White showed lower DC% in 8 mm depth compared to 4 mm depth. The control groups of both cements showed significant increased DC% in 4 mm depth compared to 6 and 8 mm depths (P<0.05). DT-White caused decreased DC% in both cements in 4 mm. DT-Light caused increased DC% of Rely X in 6 mm depth compared to DT-White and control. DT-Light increased DC% of Nexus in 6 and 8 mm depths, compared to DT-White and control groups.
Conclusion: Based on the results of this study, application of translucent fiber posts has a significant effect on degree of polymerization in dual-cure resin cements, compared to opaque types. Their better light transmission to deep areas due to the effect of optical fibers, can lead to better results.
M. Khoroushi , A. Abedini ,
Volume 20, Issue 1 (5-2007)
Abstract
Background and Aim: Patients always complain about metallic color of amalgam restorations. Covering amalgam by composite can solve this problem. Since polymerization shrinkage is a serious shortcoming in composites, application of the combined amalgam and composite restoration is one of the methods to reduce leakage in the cervical margins of posterior restorations. The aim of this invitro study was to evaluate the microleakage of amalgam/composite interface when Rely-X ARC adhesive resin cement was used in the joint.
Materials and Methods: Twenty-four sound extracted premolars were chosen. Mesial and distal class II conventional cavities were prepared and the samples were divided into 4 groups of 12. In all groups, the bases of the cavities were restored with amalgam and then the remaining part was filled by composite resin. Specimens in groups 1 and 2 were restored with composite-resin, immediately after condensing amalgam without or with application of Rely-X ARC (3M, ESPE) respectively. In groups 3 and 4, composite resin were applied 24 hours after condensation of amalgam, without or with application of Rely-X ARC respectively. After polishing and thermocycling, all specimens were prepared for dye penetration and the degree of leakage was scored and analyzed using Kruskall Wallis test with p<0.05 as the level of significance.
Results: The frequency of dye penetration in different groups was obtained. The most and the least scores were observed in groups 3 and 4 respectively. No statistically significant difference was observed in different methods.
Conclusion: None of the methods in this study could seal the amalgam/composite-resin interface.
M. Atai, M. Ghavam, E. Yasini, M. Mirzaei, A. Pahlavan, M. Hasani Tabatabaie, S. Arami, H. Kermanshah, S. Kameli,
Volume 21, Issue 2 (11-2008)
Abstract
Background and Aim: Nonmetallic tooth- colored posts adhere to canal walls by dentin bonding agents and resin cements. Better retention and proper distribution of stress result from enough and proper bonding. The purpose of this study was to evaluate bond strength of D.T. Light - post with two different resin cements (self-cure & dual-cure) and to investigate the effect of irrigating solutions applied in root canal on bond strength of the resin cements and D.T.Light- post to root canal wall.
Materials and Methods: In this experimental study 40 single root teeth (maxillary canine & central) were selected and stored in 0.1% thymol solution for one week and transferred to distilled water. The teeth were decoronated 2mm above CEJ. The canal space was mechanically enlarged using k-files (up to # 70). The teeth were randomly divided into two groups. The first group was irrigated with 2.6% NaOCl, and the second was irrigated with normal saline. After drying, the teeth were filled with gutta percha cones using lateral condensing method. After two weeks the post space was prepared and D.T.Light- post was inserted in each subgroup using self or dual-cure cements according to manufacturer's instructions. After thermocycling, the apical part was cut 1cm below CEJ. The remained length was divided into 9 equal sequential sections. Each section was submitted to shear push-out test in universal testing machine. Statistical analysis of the bond strength data was performed using ANOVA and post hoc tests with p<0.05 as the level of significance. All failed specimens were examined under stereomicroscope. Degrees of conversion of the cements were determined by FTIR.
Results: Significant difference in bond strength values were found among sites (P=0.001) and cements (P=0.03). With increasing in depth, bond strength decreased. The mean bond strength value in dual-cure resin cement was higher than self-cure cement. The irrigating solutions caused no significant difference in bond strength (P=0.46). DC% had significant difference in various depths.
Conclusion: According to the results of this investigation, bond strength of dual-cure cement is higher than self-cure one in D.T Light- post because of post's translucency. 2.6% sodium hypochlorite does not affect the bond strength.
M. Mirzayi, M. Ghavam, Z. Emami Meibodi,
Volume 21, Issue 3 (12-2008)
Abstract
Background and Aim: Polymerization shrinkage of resin cements during setting leads to stress on teeth receiving indirect esthetic restorations. Some methods like blocking out undercuts during cavity preparation with glass Ionomer can reduce the mass of resin cement and therefore the amount of stress. The aim of this study was to evaluate the fracture resistance of molar teeth, receiving class I ceramic inlays with two different methods of blocking out undercut.
Materials and Methods: In this experimental study, thirty intact molar teeth were randomly divided into three groups of 10 each. One group was maintained intact as the control group. Similar class I cavities with identical undercuts were prepared on the other groups. In group 2 the undercut was filled with light cured glass Ionomer (vitremer 3M) before making impression, and in group 3 they were blocked out in the lab before preparation of the inlay. All the teeth in test groups were restored with indirect ceramic inlays.(vitadur - Alpha/ single bond / Rely X ARC). After thermocycling load causing fracture was assessed by universal testing machine. All the specimens were examined under a steriomicroscope (X40) to determine type of fracture. The results were analyzed by one way ANOVA and Tukey HSD tests. P< 0.05 was considered as the level of significance.
Results: The restored groups showed significantly less fracture resistance than the control group. The difference between two test groups was not significant. The fracture in group2 had less destruction.
Conclusion: According to the findings of this study, blocking out the undercut with two different methods (using glass ionomer/ or blocking it out on the die) made no diferrence in fracture resistance.
S. Nokar, H. Dorriz, H. Hajimiragha, N. Shamashyan ,
Volume 22, Issue 1 (8-2009)
Abstract
Background and Aim: Debonding is the most common failure type of fiber posts. This in vitro study aimed to evaluate the bond strength of 3 different fiber posts cemented with a resin luting agent in three regions of prepared post spaces after being subjected to termocycling.
Materials and Methods Thirty six mandibular first premolars were sectioned at the cemento-enamel junction and were treated endodontically. After one week the post spaces were prepared and roots were divided into 3 groups of 12 specimens according to the post types (D.T.Composipost, D.T.White, D.T.Light). Sealbond Cement Dual II was used in all groups. One day after cementation, specimens were subjected to 3500 thermal cycles (5oC/55oC). Each root was then embedded in acrylic resin and sectioned perpendicular to long axis. Three 1-mm tick segments from apical, middle and cervical thirds were prepared. Push out test was performed. Data were analyzed with 2-way ANOVA (P<0.05). All root segments and dislodged posts were observed with stereomicroscope to figure out their failure modes.
Results: The post type had no significant effect on bond strength (p=0.08). However bond strength at the coronl segment was higher than the other segments (p=0.005). Mixed mode was the mostly occurred failure mode with D.T.Composipost and D.T.Light but with D.T.White, the mostly occurred failure mode was adhesive between the post and cement.
Conclusion: Different fiber posts have relatively similar bond strength to root dentin, bond strength at the coronl segment was higher than the other segments.
Zahra Jaberi Ansari, Mahdieh Daneshmonfared, Haleh Valizadeh Haghi,
Volume 27, Issue 1 (4-2014)
Abstract
Background and Aims : In this in vitro study, the long-term bond strength of a self-adhesive resin cement and conventional resin cements to human enamel and dentin was compared .
Materials and Methods: 80 sections of intact human third molars were randomly assigned into eight groups according to the cement type [Rely X Unicem (RXU), Rely X ARC (RXA)], bond substrate (enamel, dentin) and the duration of water storage (24 h or 1 year). Rods of cements (0.75×1 mm) were prepared on the top surface of specimens using Tygon tubes. The micro-shear bond strengths of specimens were measured by a micro-tensile tester. Data were analyzed using Wilcoxon signed ranks and Mann Whitney tests ( α =0.05).
Results: The bond strengths of RXA and RXU cements to enamel after 24h were 18.56±4.08 MPa and 14.99±4.17 MPa, and after 1 year were 19.41±6.24 MPa and 15.51±6.17 MPa, respectively. The bond strengths of RXA and RXU cements to dentin were 13.36±4.02 MPa and 14.16±4.69 MPa after 24h , and 14.63±5.96 MPa and 14.08±6.72 MPa after 1 year, respectively. Tooth substrate had significant effect only on the shear bond strength of RXA cement after 24h (P=0.01), while no other significant differences were found in this study (P>0.05).
Conclusion: According to the results of this study, one-step self-adhesive and multi-step conventional resin cements were similarly effective in bonding to enamel and dentin after 1 year water storage.
Saeed Nokar, Amir Azizi, Ahmad Rohanian,
Volume 27, Issue 1 (4-2014)
Abstract
Background and Aims: Nowadays, the application of all ceramic restorations are being raised, because of their physical characteristics, such as translucency and good appearance. Numerous researchers investigated the impact of surface treatments on the bond strength of zirconia ceramic with resin cements. The aim of this study was to compare the microshear bond strength of Cercon and Zirkonzahn (two kind of zirconia) ceramics, to two types of resin cements after thermocycling.
Materials and Methods: In this study, 24 rectangular specimens were made from each group of Cercon and Zirkonzahn ceramics. After sandblasting, these specimens were connected to 3×1 mm2 composite cylinders by two resin cements (Panavia F2 and Rely X Unicem2). After performing a thermocycling regime for 5000 cycles (5-55 ◦ C), the microshear bond strengths were measured by a universal testing machine. The mode of failures were determined by a stereomicroscope. Data were analyzed using two-way ANOVA.
Results: Type of ceramics had no significant impact on the microshear bond strength (P=0.317). The highest bond strengths in both ceramics were obtained with Reply X Unicem (P=0.035). The predominant failure mode was adhesive between the cement and ceramic.
Conclusion: Type of resin cement had a significant effect on their bond strengths to zirconia ceramics.
Ali Eskandarizadeh, Shahram Farzin Ebrahimi, Niloofar Shadman, Saeed Rahmani,
Volume 29, Issue 1 (7-2016)
Abstract
Background and Aims: Slow polymerization rate in early stage of light curing process leads to higher monomers movement and entering in polymer network that cause higher mechanical properties.The aim of this study was to evaluate the effect of light activation methodes (immediate, 5 and 10 minutes delay) on the push-out bond strength of cemented fiber posts in different regions of root canal with two types of resin cements.
Materials and Methods: In sixty extracted human single canal, the teeth were decoronated from cement enamel junction and after root canal therapy, FRC postec plus were cemented with two resin cements, Duolink and Variolink 2, in three curing methods; immediate, 5 and 10 minutes of delay. After storing in a dark place for 24 hours, they were cut into three sections: coronal, middle and apical. The push-out bond strength test was performed using a universal testing machine. The failure modes were observed using a stereomicroscope. Data were analyzed using ANOVA and Tukey post hoc test (P<0.05).
Results: In Duolink, immediate light curing had significantly higher bond strength than that of two delayed methods (P>0.05). In immediate light curing method, regardless of root region, Duolink had higher push-out bond strength than that of Variolink 2 (P=0.02). In all subgroups, there were reductions in the bond strengths from coronal to apical. Mixed failure at the cement-fiber post interface was predominent in all groups.
Conclusion: 5 and 10 minutes delay caused reduction in the push-out bond strength for Variolink 2 but did not have significant effect for Duolink resin cement.
Ali Eskandarizadeh, Shahram Farzin Ebrahimi, Niloofar Shadman, Saeed Rahmani,
Volume 30, Issue 2 (8-2017)
Abstract
Background and Aims: Delay in light irradiance can improve the polymeric structure and mechanical properties of resin cement and uniform stress distribution. The aim of this study was to evaluate the effect of light activation modes (immediate, 5 and 10-minute delay) on the push-out bond strength of cemented fiber posts with two types of resin cements in different of root canal regions.
Materials and Methods: In sixty extractedsingle canal and endodontic therapied roots, FRC Postec Plus were cemented with two resin cements, Nexus3 and Panavia F2.0, in three curing methods, immediate, 5, and 10 minute delay. After 24 hours storing in a dark place, they were cut into three sections: coronal, middle and apical. The push-out bond strength test was performed using the universal testing machine. Failure modes were evaluated using stereomicroscope. Data were analyzed by ANOVA and Tukey post hoc test with P<0.05 as the level of significance.
Results: In Nexus3, the immediate light curing had significantly higher bond strength (11.18±4.32) than delay methods (P=0.001). In Panavia F2.0, the 5-minute delay had significantly the highest bond strength (13.34±4.62) (P<0.05). There was no correlation between the different light curing methods and root canal regions. In Nexus3, the coronal region had higher bond strength (11.83±3.7) than that of middle (9.12±3.1) (P=0.015), and middle than of apical (5.65±2.77) (P=0.00), and coronal than that of apical (P=0.002). In Panavia F2.0, there were not significant differences among regions (P>0.05).
Conclusion: Delay in light curing of dual-cure resin cement's had different effects on the push-out bond strength.
Ramin Mosharraf, Aref Sadeghian,
Volume 31, Issue 3 (11-2018)
Abstract
Background and Aims: In endodontically treated teeth, the fiber posts are used to retain a core restoration. The purpose of this study was to evaluate the effect of different resin cements on the bond strength of fiber reinforced composite posts to root canal dentin, and comparing the bond strength in different sections of root.
Materials and Methods: In this in-vitro experimental study, 48 extracted single-canal central incisors were endodontically treated. For the push out test, the posts were divided into 3 groups according to one of the following three different cement materials (n=16) (Bifix SE, Bifix QM, Rebilda). Three slices with a thickness of 2-mm were prepared of each root. The push-out tests were performed at a cross-head speed of 1 mm/minute using a universal testing machine. Data were analyzed by two-way and one-way ANOVA test followed by Tukey post hoc test (α=0.05).
Results: There was no significant differences between the mean push out bond strength of three experimental groups (P=0.650), but there were significant differences between the mean push out bond strength of root dentin regions (P<0.001).
Conclusion: Under the conditions of this study, there was no significant difference between the mean push out bond strength of 3 different resin cement systems. The coronal region of root dentin showed significantly higher mean bond strength values than that of the middle and apical thirds.
Hoseinali Mahgoli, Rezvaneh Ghazanfari, Mahdi Mirmohammadi, Davoud Zare, Mahnaz Arshad,
Volume 32, Issue 3 (11-2019)
Abstract
Background and aims: Solubility is an important property of luting cements in determining clinical durability. The aim of this study was to compare the solubility of Panavia, Calibra and Maxcem resin cements with that of GC Fuji PLUS resin modified glass ionomer cement in three different pH values.
Materials and Methods: A total of 96 specimens were prepared (8mm diameter, 4mm thickness) according to manufacturer instructions. After setting, they were desiccated and weighed. The specimens were kept immersed in distilled water and lactic acid solution (pH values of 3 and 5) for 30 days and then removed and weighed again. Data were statistically analyzed by SPSS18 using two-way ANOVA with P≤0.05 set as the level of significance.
Results: The results of this study showed no significant difference between three pH values (P=0.08). The Calibra resin cement had the lowest value of solubility in distilled water and both pH of lactic acid. GC Fuji PLUS resin modified glass ionomer cement had the highest value of solubility in lactic acid and the Maxcem resin cement had the highest value of solubility in water.
Conclusion: The solubility characteristics of resin modified glass ionomer and three different resin cements were significantly affected by their composition and the storage condition.
