Evaluation of Marginal Gap and Internal Adaptation of All-Ceramic Coping Fabricated With CAD/CAM and Press-Laboratory Technique; an In Vitro Study (original) (raw)
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Evaluation Of Marginal Gap Of CAD/CAM Crowns Milled From Two Ceramic Materials
Egyptian Dental Journal, 2018
Aim: The purpose of this invitro study was to evaluate and compare the marginal gap of CAD CAM crowns milled from two ceramic materials. Materials and methods: Sixteen natural sound upper first molars were prepared for full coverage crowns using computer numerical control (CNC) .CAD CAM all ceramic crowns were fabricated and seated to the corresponding molars. Samples were divided into two groups according to the ceramic material ; group (E): Emax CAD ( Lithium disilicate glass ceramics ) (n=8), group (V): Vita suprinity( Zirconia reinforced lithium silicate ceramic ) (n=8). Vertical marginal gap of all samples was measured by digital microscope.Results: Emax CAD group ( Lithium disilicate glass ceramics )showed significantly higher marginal gap values (M=95.4, SD=8.27) in comparison with Vita suprinity group ( Zirconia reinforced lithium silicate ceramic ) (M=75.47, SD=8.9).Conclusions: Marginal gap values were within the clinically acceptable range where full coverage Emax CAD cro...
Journal of Pure and Applied Microbiology, 2018
The objective of this in vitro study was to evaluate and compare the marginal and internal gaps of full contour zirconia crowns using three different digital intra-oral scanners with different software design. Samples were distributed into five groups eight for each according to the type of scanner and software design used during milling procedure as follows: Group A: CEREC Omnicom + InLab SW 16.1. Group B: TRIOS3 + software of 3Shape dental system. Group C: TRIOS3 + InLab SW 16.1. Group D: CS3600 + software of exocad program. Group E: CS3600 + InLab SW 16.1. The crowns of all groups were milled with the same milling machine inLab MCX5. The marginal and internal fitness of crown was evaluated by direct measurement of cement thickness through sectioning procedure. The data were then analyzed using One-way ANOVA test and Tukey's (HSD) test. The results of this study showed that the least marginal gap was recorded in Group C (59.038, ±9.667) followed by Group D (63.405, ±6.038), Group E (64.674, ±6.478), Group B (70.112, ±4.954) and Group A (81.703, ±7.428) respectively. While for the internal gap, the least internal gap was recorded at Group C and Group B (119.691, ±4.107), (119.192, ±4.068) respectively followed by Group A (123.254, ±6.777), Group D (123.485, ±5.353) and Group E (130.816, ±3.926). As a conclusion, the intra-oral scanner that provides more accurate seating of monolithic crown restoration was TRIOS3.
Applied Sciences, 2021
Background: This study compared the marginal gap (MG) and absolute marginal discrepancy (AMD) of computer-aided design and computer-aided manufacturing (CAD–CAM) used in open systems (OSs) and closed systems (CSs) for producing monolithic zirconia-reinforced lithium silicate (ZLS) ceramic crowns. Methods: 60 ZLS ceramic crowns were cemented to abutment acrylic teeth; thirty crowns were designed and milled by an OS, and thirty by a CS. All crowns were sectioned for evaluating the marginal gap by scanning electronic microscopy (SEM). To compare the marginal gap between CS and OS techniques, data were analyzed using the independent-samples Mann–Whitney U Test (α = 0.05). Results: AMD was found to be significantly better for the closed system (p < 0.05). Mean AMD values for the CS were 148 µm, and for the OS it was 196 µm. MG was found to be significantly better for the OS (p < 0.05). Mean MG values for the CS were 55 µm, and for the OS they were 38 µm. Conclusions: The marginal g...
A Comparison of Marginal Gaps of All-Ceramic Crowns Constructed from Scanned Impressions and Models
The International journal of prosthodontics
This study compared the marginal gaps of computer-aided design/computer-aided manufacture (CAD/CAM)-fabricated all-ceramic crowns constructed from scanned impressions and models and with two different occlusal reduction designs. Two typodont mandibular first molars were prepared to receive CAD/CAM-fabricated all-ceramic crowns. Both molars were prepared to ideal crown reduction, the first with anatomical occlusal reduction (AOR) and the second with completely flat occlusal reduction (FOR). Nine polyvinyl siloxane impressions (PVS) were taken, and nine stone replicas fabricated for each preparation. All impressions and stone models were scanned using a laser scanner (Planmeca Planscan, E4D technologies), and 36 lithium disilicate (IPS e.max CAD) crowns were milled. The marginal gap was measured in four locations using a light stereomicroscope. Crowns constructed from preparations with both occlusal reduction designs demonstrated similar marginal gaps (FOR = 97.98; AOR = 89.12; P = .7...
The aim of this study was to evaluate the marginal discrepancy (MD) and internal discrepancy (ID) of ceramic crowns manufactured by a CAD/CAM system, having different finish lines. The hypotheses tested were that the finish line type would not influence the MD or ID of the crowns, and ID would not change in different regions. Materials and Methods: Three aluminum master dies (height: 5.5 mm, Ø: 7.5 mm, conicity: 6 • ) with different finish lines (TC: tilted chamfer; LC: large chamfer; RS: rounded shoulder) were manufactured. Ten impressions were made from each master die using a modified parallelometer. Impressions were poured in type IV dental stone, and 30 ceramic crowns (IPS Empress CAD, Ivoclar) were subsequently milled. The crowns were fixed on their respective metallic die using a metallic fixation device. The distance between the external edges of the crown to the edge of the cervical preparation was performed at 50 points on the respective metallic die (MD analysis). With the replica technique, the ID values of each crown were further evaluated at 12 points equidistant to each other in three regions: radius (R), axial (A), and occlusal (Occl). The measurements were performed using an optical microscope (250×). The data (μm) were analyzed using ANOVA and Tukey s test (5%). Results: The RS group (28.24 ± 11.42 μm) showed significantly lower MD values (p = 0.001) than those of TC (99.92 ± 18.32 μm) and LC (64.71 ± 25.64 μm) groups, both of which also differed statistically from one another. The ID results demonstrated significantly lower values in the LC group (183.01 ± 62.82 μm) (p = 0.0014) than those of TC (216.26 ± 83.23 μm) and RS (219.12 ± 87.24 μm) groups. ID results of TC and RS were not significantly different. Additionally, the ID results showed significant differences among the regions (p = 0.0001). The null hypotheses were rejected. Conclusion: The RS finish line produced MD values significantly lower than tilted and large chamfer, but large chamfer presented the lowest internal discrepancy values. Independent of the finish line type, internal discrepancy was the lowest in the axial region followed by radius and occlusal regions.
Brazilian Journal of Oral Sciences, 2020
The aim of this study was to evaluate the marginal adaptation of ceramic and composite resin crowns fabricated with computer-aided design and computer-aided manufacturing (CAD/CAM) technology using an intraoral digital scanner. Methods: A human mandibular right second molar was prepared for a ceramic crown. The impressions were made using intraoral scanning device and crowns were milled. Ten crowns were fabricated for each group (n=10): GF-Feldspathic Ceramic (Cerec Blocs, Sirona), GL-Lithium Disilicate Ceramic (IPS e.max CAD, Ivoclar), GG-composite resin (Grandio Blocs, VOCO) and GB-composite resin (Brava Block, FGM). The marginal gap was measured for each specimen at 4 points under magnification with a stereomicroscope. All data were statistically analyzed using one-way ANOVA followed by the Tukey's test (α=.05). Results: The lowest marginal discrepancy value was observed in GB (60.95 ± 13.64 μm), which was statistically different from the GL (84.22 ± 20.86 μm). However, there was no statistically significant difference between these groups when compared with the other groups, GF (73.26 ± 8.19 μm) and GG (68.42 ± 11.31 μm). Conclusion: It can be concluded that the composite resin presented the lowest variance compared to the lithium disilicate glass ceramic, although the marginal gap of all materials tested was within the acceptable clinical limit (120 μm).
Quintessence International, 2009
OBJECTIVE: To evaluate the effect of different preparation angles on the marginal and internal fit of zirconia single-crown copings.METHOD AND MATERIALS: Three ivorine maxillary right first molars were prepared with preparation angles of 4, 8, and 12 degrees. Impressions were made of each abutment tooth to obtain 20 specimens per group. The copings were manufactured by a CAD/CAM system and milled from semi-sintered zirconia blanks. After sintering, 10 copings were randomly chosen from each group and adapted by a dental technician. All 60 copings were cemented with glass ionomer on the master casts. After embedding, all specimens were cross-sectioned. Both marginal and internal fit were evaluated under an optical microscope. A 1-way analysis of variance (ANOVA) and a nonparametric test (Mann-Whitney U) were used to compare data (a = .05).RESULTS: The 4-degree copings showed a mean marginal gap of 91 microm (+/- 15) before and 67 microm (+/- 8) after adaptation; the 8-degree group exhibited a mean marginal gap of 82 microm (+/- 13) before and 67 microm (+/- 11) after adaptation; the 12-degree specimens showed 50 microm (+/- 6) before and 46 microm (+/- 6) after adaptation. Adaptation led to a significant improvement of specimens from the 4-degree and 8-degree groups, while no statistical difference could be observed among 12-degree specimens before and after adaptation.CONCLUSION: The highest marginal gaps were found in the 4- and 8-degree groups. In the group with 12-degree preparation angle, additional adaptation did not improve the fit and can be considered unnecessary under the conditions of this study.
Applied Sciences
Background: This study compared the influence of three different radial spacers (60,90,120 microns) on the marginal gap adaptation by using computer-aided manufacturing (CAD-CAM) for producing monolithic zirconia reinforced lithium silicate (ZLS) ceramic crowns. Methods: A total of 45 abutment acrylic teeth were divided into three groups of different radial spacers (60, 90, and 120 microns). In each group 15 teeth were scanned by Omnicam intra oral scanner and ZLS crowns were ground. For each unit the marginal gap was evaluated at four regions of interest by scanning electronic microscope (SEM). To compare the marginal gap between the three groups a one-way ANOVA with post-hoc Bonferroni test was preformed (α = 0.05). Results: The marginal gap for a 60 microns (162.99 ± 16.25 µm) radial spacer was found significantly higher than 90 (41.85 ± 3.57 µm) and 120 (41.85 ± 5.3 µm) microns radial spacers (p < 0.05). Between 90- and 120-micron radial spacers no difference was obtained. (p...
To evaluate the effect of finish line design (chamfer and feather-edge) and ceramic type on the internal and marginal fits of fixed partial dentures on abutment teeth. Materials and methods: Two typodont mandibular casts, missing right first premolar tooth, received tooth preparation on canine and second premolar abutments (one cast with chamfer finish line and the other cast with feather-edge finish line). The preparation segment of each typodont model was scanned, 3D printed in resin, and then invested and casted in metal to obtain two metal models. Polyvinyl siloxane impressions were made for the metal models and poured in type IV stone. The stone models (n = 40) were randomly assigned into four groups (n = 10): chamfer finish line with heat-pressed zirconia reinforced lithium disilicate fixed partial denture (CL), chamfer finish line with monolithic zirconia fixed partial denture (CZ), feather-edge finish line with heat-pressed zirconia-reinforced lithium disilicate fixed partial denture (FL), and feather-edge finish line with monolithic zirconia fixed partial denture (FZ). After the fabrication of ceramic restoration, micro-computed tomography was used to evaluate the internal and marginal fits of each fixed partial denture. Data were statistically analyzed with three-way ANOVA (α = 0.05). Results: There were no significant interactions between preparation type, material type, and tooth type at any of the areas assessed. There was significant difference (p = 0.01) between CZ (59.15 ± 4.6 µm) and FZ (73.6 ± 17.1 µm) groups at the finish line area. Regarding the horizontal marginal discrepancy area, there were significant differences between CZ (62.65 ± 10.5 µm) and FZ (90.05 ± 5.6 µm) groups (p < 0.001), CL (77.45 ± 8.1 µm) and CZ (62.65 ± 10.5 µm) groups (p < 0.001), and FZ (90.05 ± 5.6 µm) and CL (77.45 ± 8.1 µm) groups (p < 0.001). At finish line area, there was a significant difference (p = 0.018) between feather-edge with canine (72.75 ± 13.3 µm) and chamfer with canine (59.05 ± 5.8 µm); however, there was no significant difference (p = 0.774) between feather-edge with premolar (69.45 ± 12 µm) and chamfer with premolar (65.1 ± 7.4 µm). Moreover, there was no significant difference (p = 0.886) between feather-edge with canine and feather-edge with premolar. Conclusions: The internal and marginal fits of the ceramic fixed partial dentures can be affected by the finish line design and ceramic type. The feather-edge finish line had a negative impact on the marginal and internal fits of ceramic fixed partial dentures e90
The margins of fixed restoration should be closely adapted to the cavosurface finish line to survive in the harsh biological environment of the oral cavity. This invitro study was designed to evaluate and compare the influence of two different cervical finish line types (shoulder & radial shoulder) on the marginal adaptation of two different all-ceramic CAD/CAM systems (Cerec 3& Lava) before and after veneering ceramic over the Zirconia copings. Two nickel-chromium metal dies were fabricated which replicates all-ceramic crown preparations with two different finish line configurations i.e. shoulder & radial shoulder one each. A total of 28 Y-TZP (zirconia) coping samples were fabricated using Cerec 3 & Lava CAD/CAM systems (14 each). Out of 14 zirconia coping samples in each system, seven were fabricated with shoulder and remaining seven with radial shoulder margin. All coping were evaluated for absolute marginal opening (AMO) using Reichert Polyvar-Met 2 Optical Microscope using image processing software(Lucia) and all the measurements were subjected to statistical analysis using " unpaired " t " test " with p<0.05 was considered as the level of significance. The mean AMO measurements (µm) of the Lava coping samples (68.03+20.29) were significantly lower than that of Cerec3 coping samples (88+15.72) with shoulder margins (p<0.05) whereas with radial shoulder margins, Lava coping samples (42.89+4.03) were slightly higher than Cerec 3 coping samples (41.39+3.35). " P "-value between Cerec 3 and Lava coping samples with shoulder and radial shoulder margin were not statistically significant (p<0.05).The mean AMO measurements (µm) of the Lava coping as well as crown samples with shoulder margin were less compared to Cerec 3 coping and crown samples. The mean AMO measurements (µm) of Cerec 3 coping samples with radial shoulder margins is less than Lava coping samples but identical with crown samples.Within the limitations of the study, for better marginal adaptation, radial shoulder finish line is suggested for Cerec 3 and shoulder finish line for Lava CAD-CAM systems.