In Vitro Evaluation of the Effect of Different Luting Cements and Tooth Preparation Angle on theMicroleakage of Zirconia Crowns (original) (raw)
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International Journal of Dentistry, 2016
Objectives. To evaluate microleakage and absolute marginal discrepancy (AMD) and to assess correlation between AMD and microleakage with four resin luting cements.Material and Methods. 20 extracted human third molars were prepared for full-coverage crowns. 20 zirconia copings were made (LAVA, 3M ESPE) and cemented. Specimens were randomly allocated for each used type of cement into 4 groups, RelyX® (Rx), Multilink® (Mk), PANAVIA 2.1® (P), and Maxcem® (Mx) and immersed in 10% safranin for 72 hours. 20x magnification lenses were used to observe microleakage areas (μm2) and images software was used to measure AMD areas (μm). Discrepancy and microleakage between the cements were compared with one-way ANOVA test with confidence interval of 95%.Results. Rx Group showed microleakage has lowest value and AMD has highest value. P Group showed microleakage has the highest value and Mk Group presented AMD has lowest value. There were no significative differences between the cements. There were...
Brazilian Dental Science
Objective: To evaluate the marginal fit and microleakage of monolithic zirconia crowns cemented with bioactive cement (Ceramir) compared to that cemented with glass ionomer cement and to evaluate the effect of thermocycling on marginal fit. Materials and methods: Twenty sound human molar teeth were prepared to receive a monolithic zirconia crowns. Teeth were divided randomly into two equal groups according to the type of luting cement. Group I: glass ionomer cement and group II: Ceramir cement. After cementation, the vertical marginal gap was assessed by using stereomicroscope before and after thermocycling. Twenty equidistant measurement points were taken for each crown. Leakage assessment was carried out using Fuchsin dye penetration followed by digital photography under a stereomicroscope. Data were analyzed by Mann-Whitney U test to compare between the two luting cements. Wilcoxon signed-rank test was used to evaluate the effect of thermocycling on the marginal fit (P ≤ 0.05) Re...
The International Journal of Prosthodontics
L ong-term success of indirect restorations is associated with accurate luting procedures, among other factors. 1 Resin cements have been recommended for luting densely sintered, high-strength oxide ceramics, such as zirconia, in order to improve the retention and sealing of indirect restorations. 2 The use of phosphate monomer-containing composite cements in association with specific surface pretreatments (such as airborne-particle abrasion or silica-coating) of zirconia-based prostheses is currently suggested to develop satisfactory bonding to coronal dentin. 2,3 Other classes of commonly used cements, such as resin-modified glassionomers (RMGI), have demonstrated lower initial and long-term bond strengths to zirconia than phosphate monomer-containing composite cements. 4,5 On the other Purpose: To evaluate the amount of residual cement (ECL) around the margins of zirconia crown copings after careful luting and cleaning procedures and to investigate these factors in relation to two tested luting materials. Materials and Methods: An experimental model of a maxillary arch was selected for this in vitro study. The maxillary first molar was prepared to receive an all-ceramic, single, full-crown restoration with a finish line located 1 mm below the artificial gingiva. After scanning of the prepared tooth, 20 paired zirconia coping-abutment assemblies were CAD/CAM fabricated. A slot in the model allowed for insertion and removal of the assemblies for each new test. Specimens were divided into two groups according to the cementation procedure: half (n = 10) were luted using a resin-modified glass-ionomer (RMGI) (Ketac-Cem Plus) (GI group), and the other half with a dual-curing self-adhesive resin agent (RelyX Unicem 2) (UN group). The substructures were loaded with cement, and a customized preseating device was adopted for preliminary reduction of excess. The zirconia copings were finally seated on their respective abutments located on the simulation model. A blinded investigator attempted to remove all excess cement with clinically available instruments. The amount of excess cement left in situ after cleaning procedures was weighed in grams. Dislodging forces of luted coping-abutment assemblies were obtained by using pull-off tests in a universal testing machine (crosshead speed of 0.5 mm/minute) after 24 hours of water storage. Means and standard deviations were calculated for ECL and for retention force values, and Mann-Whitney and ANOVA tests were carried out to detect significant differences (α = .05) among groups. Results: Cement remnants were found in all specimens despite the cleaning procedures, with a typical distribution in interproximal areas. Mean ECL values for the GI and UN groups were 0.0079 ± 0.0060 and 0.0107 ± 0.0081, respectively. No statistically significant differences were found between tested cements (P = .3284). Removal stress values (MPa) were significantly higher (P = .0313) for the UN group (12.4 ± 6.5) than for the GI group (6.57 ± 4.69). Conclusion: Similar amounts of undetected cement remnants were discovered around the esthetic margins of zirconia crown copings regardless of cement type. The luting procedure using the self-adhesive resin cement provided significantly higher early retention values than the RMGI material.
Journal of Research in Medical and Dental Science, 2020
Objectives: The purpose of this in vitro study was to evaluate and compare the effect of different marginal cement space parameter setting in the CAD software on the marginal and internal fitness of monolithic zirconia crowns with different luting agent. Materials and method: 48 sound human maxillary first permanent premolar teeth of comparable size and shape extracted for orthodontic purposes were collected and selected to be used in this in vitro study. All the dimensions of each crown were tested with using one way ANOVA in order to reduce the confounding variables. The teeth samples were divided into two main groups according to the different marginal cement space parameter setting (n=24) as following: Group I: 0 cement space around the margin and additional cement space of 80 Mm starting 1mm above the finish lines of the teeth. Group II: 25 Mm cement space around the margin and additional cement space of 80 Mm starting 1mm above the finish lines of the teeth. Each group was sub...
2020
Objectives: The purpose of this in vitro study was to evaluate and compare the effect of different marginal cement space parameter setting in the CAD software on the marginal and internal fitness of monolithic zirconia crowns with different luting agent. Materials and method: 48 sound human maxillary first permanent premolar teeth of comparable size and shape extracted for orthodontic purposes were collected and selected to be used in this in vitro study. All the dimensions of each crown were tested with using one way ANOVA in order to reduce the confounding variables. The teeth samples were divided into two main groups according to the different marginal cement space parameter setting (n=24) as following: Group I: 0 cement space around the margin and additional cement space of 80 Mm starting 1mm above the finish lines of the teeth. Group II: 25 Mm cement space around the margin and additional cement space of 80 Mm starting 1mm above the finish lines of the teeth. Each group was sub...
Retention of Zirconia Crowns with Different Surface Treatment and Adhesive Cements
Objectives: The aim of this in-vitro study was to evaluate the effect of different surface treatment and resin cements on the retention of monolithic zirconia crowns. Materials and Methods: A total of 40 maxillary premolars extracted for orthodontic cause from the outpatient dental clinic, Faculty of Dentistry, Mansoura University, Egypt, were used in this study. Teeth were randomly divided into 4 groups according to the surface treatment and cement used (n=10) into: Group AHP :(Airborne particles abrasion and hot acids + Panavia SA cement plus), Group AHL :(Airborne particles abrasion and hot acid + G-CEM Link Force Cement), Group AP: (Airborne particles abrasion + Panavia SA cement) and Group AL: (Airborne particles abrasion+ G-CEM Link Force cement). The preparations were performed using computer aided design/computer aided manufacturing (CAD/CAM) technology to standardize the preparation, the prepared teeth scanned by optical scanner, CubeX 2 zirconia crowns (Dental Direkt GbmH, Spenge,Germany) were fabricated for each preparation. Crowns cemented to preparations after surface treatment of its internal surfaces. And after 10,000 thermalcycles, retention test was performed using a universal testing machine (0.5 mm/min). Results: There was significance difference between two surface treatments and cements. Application of hot acids after airborne particles abrasion and using of MDP self-adhesive resin cement improved retention significantly Conclusion: Retention of zirconia crowns improved by using hot acids after airborne particles abrasion.
Pre-cementation procedures’ effect on dental zirconias with different yttria content
Dental Materials
Objectve. Several pre-cementation procedures have been advocated to enhance adhesion between zirconia and resin-based cement. There is, however, limited documentation on how these pre-treatments affect the strength of zirconia crowns as most tests are performed on discs or bars. The aim was to assess the effect of pre-cementation procedures on fracture mode, fracture strength and cement retention on zirconia. Methods. Two dental zirconia materials with different yttria content were assessed (<4 and>5 mol%). Both discs (n = 45) and crown-shaped specimens (n = 30) of the two materials were pretreated with either air-abrasion or hot-etching with KHF 2 and compared with untreated controls with regards to surface roughness, crystallography, wettability, cement adhesion and fracture strength. Results and Significance. Air-abrasion improves adhesion and strength of zirconia with moderate yttria content (<4 mol%). Acid etching with heated KHF 2 showed the best effect on strength and cement retention on zirconia with higher yttria content (>5 mol%). Application of KHF 2 was, however, complicated on crown-shaped specimens. Pre-treatment and cementation protocols should be optimized for different dental zirconias to improve both strength and retention.
Influence of Luting Cement on the Clinical Outcomes of Zirconia Pediatric Crowns
Case Medical Research, 2019
Background: There is no scientific evidence supporting the choice of luting cement for cementation of zirconia crowns. Aim: The purpose of this split-mouth study was to compare the efficacy of using Bio-active cement versus Packable glass ionomer for cementation of posterior pediatric zirconia crowns. Design: 50 first mandibular primary molars were restored by zirconia crowns and were randomly divided to be luted with either; 1) Bio-active cement, 2)
Effect of Cement Gap on the Retention of Zirconia Crown
2020
Objective: To evaluate the effect of different cement gap on retention of zirconia crowns cemented with resin cement. Materials and methods: Thirty natural human molar teeth were collected and mounted in an acrylic mold. Teeth were prepared through CNC, and then zirconia crowns fabricated by CAD/CAM. Samples were divided into 3 subgroups according to the cement gap (CG) (n=10): 25μm (CG25), 50μm (CG50), 100μm (CG100). Zirconia crowns cemented with Breeze Self-Adhesive Resin Cement. Samples were thermocycled for 5000 cycles between two water baths at 5 ̊C and 55 ̊C with a dwell time of 20 seconds and 10 seconds of transfer time. Samples were subjected to tensile test, dislodgment force recorded in MPa. Results: No significant difference was found between mean pull-out bond strength at different cement gaps. Conclusion: The 25 μm cement gap gave the best retention for zirconia restorations.
Effect of surface treatment on the retention of zirconia crowns to tooth structure after aging
Journal of Esthetic and Restorative Dentistry, 2020
Objective: To evaluate the effect of different surface treatments on the retention between zirconia crowns and tooth structure after in vitro aging. Materials and methods: Human third molars (n = 44) received crown preparations and CAD/CAM zirconia crowns were manufactured. Specimens were divided into two groups: no aging, control (NAC, n = 11) or aging (A, n = 33). NAC were bonded with universal adhesive (UA). Aged specimens were divided into three subgroups (n = 11) according to surface treatment: Control: no abrasion + UA; Alumina: alumina abrasion + UA; Silica: tribochemical silica coating + UA. The crowns were cemented with dual-cure resin cement. Specimens in group A were aged by a combination of mechanical, thermal, and pH cycling. Retention strength values were obtained by tensile tests and results were analyzed by one-way analysis of variance (ANOVA) and Tukey test (P < .05). Results: Aging decreased the retention strength in control specimens (P < .001). Surface treatment improved the retention strength of aged specimens (P < .001), with similar results between alumina and tribochemical silica coating. Conclusion: The chemical interaction between the universal bonding system and zirconia's surface was not sufficient to withstand artificial aging. Tribochemical silica coating did not promote additional retention in comparison to alumina blasting. Clinical significance: The long-term retention of translucent zirconia crowns to tooth structure using phosphate-based materials is improved by means of mechanical surface treatments such as alumina blasting and tribochemical silica coating. K E Y W O R D S airborne particle abrasion, aging, translucent zirconia, universal adhesive, zirconia crown 1 | INTRODUCTION Polycrystalline tetragonal zirconia stabilized with 3 mol% of yttria (3Y-TZP) has been largely used for the restoration of heavily destroyed teeth. 1 In spite of having excellent mechanical properties and biocompatibility, 3Y-TZP exhibits a high level of opacity and needs to be veneered with porcelain to mimic the optical properties of the tooth structure. 2,3 One of the strategies to enhance translucency of zirconia is to increase the yttria content to 4 mol% (4Y-PSZ) or 5 mol % (5Y-PSZ), resulting in partially stabilized materials. 4 The higher yttria content introduces an optically isotropic cubic phase into the crystalline phase composition of zirconia, which minimizes opacity and makes zirconia more suitable for monolithic anterior restorations. 4-6