Evaluation of internal and marginal fit of two metal ceramic system - in vitro study (original) (raw)
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Revista de Chimie
Copings accuracy is an important factor for long-term clinical success of ceramic fused to metal dental restorations. The purpose of the study was to investigate marginal and internal fit of metal-ceramic crowns during processing, using conventional and digitized technologies. Metal copings were produced by Digital light Processing (DLP), invested and casted. Ceramic veneers were overpressed. Internal and marginal fit was measured using silicon replica technique for patterns, casted frameworks and final ceramic fused to metal crowns. Best adaptation was found in resin-pattern group, with small increasing of gap after casting and after ceramic pressing.
2017
PURPOSE: To compare the marginal fit of all metal, porcelain fused to metal and all ceramic crowns fabricated using different materials and techniques commercially available. MATERIALS AND METHODS: 80 freshly extracted human mandibular first premolars were divided into 8 groups of 10 each which received Nickel-Chromium (Ni-Cr) all metal (AM) crowns, Cobalt-Chromium (Co-Cr) AM crowns, Ni-Cr three-quarter crowns, Co-Cr three quarter crowns, porcelain fused to metal (PFM) crowns with Ni-Cr copings, PFM crowns with Co-Cr copings, pressed all ceramic (AC) crowns and CAD/CAM fabricated AC crowns respectively. Crowns were cemented and specimen were sectioned buccolingually. The marginal gap was evaluated under a stereomicroscope. Lesser marginal gap indicated a better marginal fit. RESULTS: The mean marginal gap was maximum for Group 8 (222.3 μm) and least for Group 1 (85.5 μm). The mean marginal gaps for ‘all metal crowns’ and ‘metal ceramic crowns’ showed significantly lesser marginal ga...
Dental Journal of Advance Studies, 2017
Purpose: The purpose of this in vitro study was to evaluate marginal fit of cobalt- chromium (Co-Cr) copings fabricated by direct metal laser sintering system (DMLS) and conventional lost-wax technique (LW). Materials and method: Forty tooth preparations were carried out over extracted mandibular molars. They were divided into two groups A and B of 20 each. For group A Co-Cr copings were fabricated by direct metal laser sintering (DMLS) and for group B by lost wax technique (LW). Glass –ionomer cement (GIC) was used to tack the copings over their preparations. Marginal fit was then evaluated directly under the stereomicroscope. Results: The mean marginal gap of group A was 27.9 ± 2.4 μm and group B was 40.4 ±6 μm. Statistical analysis using t - test showed highly significant difference (P>.05) between the marginal mean of the DMLS (group A) compared to LW (group B). Conclusion: The DMLS copings demonstrated superior marginal fit compared to that of conventional Co-Cr casted copings.
International Journal of Current Research and Review, 2021
Introduction: Porcelain fused to the metal prosthesis is one of the widely used dental prosthesis. The aim of this in vitro study is to check the marginal fit of a single implant-supported metal-ceramic crown fabricated by the direct metal laser sintering method compared with crowns fabricated using the lost wax technique. Materials and Method: The study conducted compares the marginal fit of single implant-supported porcelain fused to metal crown fabricated using the most ancient and conventional lost wax technique and the most recent yet emerging Direct Metal Laser Sintering (DMLS) technique. This study also compares both techniques based on the marginal fit of crowns. A total of 20 porcelain fused to metal crowns were prepared for this study. 20 implant abutments fixed into implant analogues, embedded into acrylic resin blocks were divided equally (n=10) into two groups Group A (lost-wax technique) and Group B (DMLS technique). On the abutments, crowns for the mandibular first molar were prepared by these two techniques. Four points were marked on each aspect (lingual, buccal, mesial and distal) of the crown at the level of the abutment, which was analyzed under a stereomicroscope at 65x. Three readings at each point were noted and the observations were statistically analyzed. Results: The lowest mean marginal discrepancy values (39.9 ± 1.8 µm), (40.3 ± 1.5µm), (39.2 ± 1.2µm) and (37.3 ± 1.7µm) were observed for Group B (DMLS) at all four points marked, respectively which were significantly better as compared to that of Group A (Lost-Wax) that showed (58.4 ± 1.2µm), (55.5 ± 0.98µm), (56.9 ± 0.91µm) and (55.7 ± 0.92 µm) values at the four marked points. Conclusion: The results revealed that the crowns fabricated by the DMLS technique provided better marginal fit as compared to the crowns fabricated by the Lost-Wax technique.
Evaluation of marginal and internal fit of ceramic crown copings
Dental Materials, 2013
Objectives. (1) To measure the marginal and internal adaptation of different prosthetic crowns infrastructures (IS); (2) to analyze two types of methodologies (replica and weight technique) used to evaluate the adaptation of indirect restorations. Methods. Ceramic IS were fabricated using CAD/CAM technology and slip-casting technique, and metal IS were produced by casting (n = 10). For each experimental group, the adaptation was evaluated with the replica (RT) and the weight technique (WT), using an impression material (low viscosity silicon) to simulate the luting agent. Cross-sectional images of the silicon replica were obtained and analyzed with Image J software to measure the low viscosity silicon layer thickness at predetermined points. The silicon layer was also weighted. Results were statistically analyzed with ANOVA and Tukey's test (˛ = 0.05). Pearson correlation was used to analyze the relation between the two types of evaluation methods. Results. All IS evaluated showed clinically acceptable internal and marginal adaptation. Metal IS showed the best adaptation, irrespective of the measuring technique (RT and WT). The IS produced by CAD-CAM showed greater gap values at the occlusal area than at other evaluated regions. The IS produced by the dental laboratory technician showed similar gap values at all evaluated regions. There is no correlation between RT and WT (p > 0.05). Significance. Different levels of adaptation were found for the different experimental groups and for the different evaluation methods. However, all IS evaluated showed clinically acceptable values of marginal and internal adaptation.
Marginal Fit of Metal-Ceramic Copings: Effect of Luting Cements and Tooth Preparation Design
Journal of prosthodontics : official journal of the American College of Prosthodontists, 2017
To evaluate the effect of the triad finish line design, axial wall convergence angle, and luting cement on the marginal fit of metal copings used in metal-ceramic crowns. Schematic dies and their respective copings were cast in NiCr alloy. The dies exhibited the following finish line/convergence angle combinations: sloping shoulder/6°, sloping shoulder/20°, shoulder/6°, shoulder/20°. Marginal fit was evaluated under a stereomicroscope, before and after cementation. Copings were air-abraded with 50 μm Al O particles and cemented with Cimento de Zinco, RelyX U100, or Panavia F cements (n = 10/group). Data were square-root transformed and analyzed by 3-way factorial random effect model and Tukey's post hoc test (α = 0.05). Statistical analysis showed significance for the interactions finish line and convergence angle (p < 0.05), convergence angle and time (p < 0.001), and luting cement and time (p < 0.001). Sloping shoulder/20° provided the highest marginal discrepancy whe...
Journal of Contemporary Dentistry, 2012
Aim To evaluate and compare the marginal fit of crowns fabricated by three All Ceramic CAD-CAM systems using their respective scanners. Objectives 1. To evaluate the marginal fit of All Ceramic crowns fabricated using Contact scanner- Procera system. 2. To evaluate the marginal fit of All Ceramic crowns fabricated using Optical scanner-Lava system. 3. To evaluate the marginal fit of All Ceramic crowns fabricated using Laser scanner-Cercon system. 4. To compare the marginal fit of crowns fabricated by three All Ceramic CAD-CAM systems using their respective scanner-Contact scanner, Optical scanner and Laser scanner. Materials and Methods 5 crowns fabricated with Contact scanner- Procera system (Group I), 5 crowns fabricated with Optical scanner-Lava system (Group II), 5 crowns fabricated with Laser scanner-Cercon system(Group III). The marginal fit would be evaluated at two stages for each group: A- Pre-veneering stage (coping) B-Post-veneering stage (crown). Results The mean value o...
In vitro evaluation of the marginal fit of different all-ceramic crowns
Journal of Dental Sciences, 2013
Background/purpose: The marginal fit of all-ceramic restorations is a very important criterion for their long-term success. The aim of this in vitro study was to compare the marginal adaptation of crowns fabricated with four different all-ceramic systems using an image analysis method. Materials and methods: A standardized all-ceramic preparation was made on a stainless steel die. Eighty gypsum dies were duplicated from this die and randomly divided into four groups of 20 each. Cerec 3, In-Ceram, IPS Empress 2, and Celay crowns were fabricated on dies of each group following the manufacturers' instructions. Marginal gaps of the crowns were evaluated without cementation on their own gypsum dies and then on the master die with a stereomicroscope and image analysis program. Two-way analysis of variance and Tukey's honest significant difference tests were used to evaluate the data (a Z 0.01). Results: Mean gap dimensions and standard deviations at the marginal opening of the crowns evaluated on the gypsum dies were 21.5 AE 4 mm for Celay, 29.3 AE 5 mm for IPS Empress 2, 33 AE 4 mm for Cerec 3, and 74.6 AE 10 mm for In-Ceram crowns. Mean gap dimensions and standard deviations at the marginal opening of crowns evaluated on the master steel die were 27.8 AE 4 mm for Celay, 41.5 AE 7 mm for IPS Empress 2, 47.4 AE 5 mm for Cerec 3, and 94.9 AE 10 mm for In-Ceram crowns. Marginal opening values measured on the master die were higher than those of gypsum dies. Conclusion: In-Ceram all-ceramic crowns showed the largest marginal gap, and Celay crowns showed the smallest marginal gap in both die groups. The marginal discrepancies found in this study were all within the clinically acceptable standard of 120 mm.
Effect of Coping Materials and Designs to the Marginal Adaptation of Metal Porcelain Crowns
International journal of health sciences
The Metal porcelain crowns are still widely used because of the clinically satisfactory mechanical, esthetic, marginal and internal adaptation properties and affordable, but metal collars on the marginal labial are not aesthetically acceptable because of dark shadows in the cervical region which can be overcome by marginal porcelain butt joint coping design on the marginal labial. Recent clinical studies have introduced a type of cobalt chromium coping material that is biologically more biocompatible than nickel chromium which can cause allergic reactions. In this study, Ni-Cr and Co-Cr coping materials were used with full metal collarless and modified metal collarless coping designs. The purpose of this study was to determine the effect of material and coping design on the marginal adaptation of metal porcelain crowns. This type of research is experimental laboratory. The typodontic central incisor teeth were prepared and duplicated using CAD/CAM to become zirconia and implanted in...