scholarly journals Marginal and Internal Adaptation of Zirconium Dioxide Ceramic Copings and Crowns with Different Finish Line Designs

2007 ◽  
Vol 26 (5) ◽  
pp. 659-664 ◽  
Author(s):  
Futoshi KOMINE ◽  
Takayuki IWAI ◽  
Kazuhisa KOBAYASHI ◽  
Hideo MATSUMURA
Atomic Energy ◽  
1995 ◽  
Vol 79 (6) ◽  
pp. 857-862 ◽  
Author(s):  
F. A. Akopov ◽  
T. I. Borodina ◽  
G. E. Val'yano ◽  
L. P. Krishchenko ◽  
V. N. Mineev ◽  
...  

2020 ◽  
Vol 9 (5) ◽  
pp. 414-422
Author(s):  
Safoura Ghodsi ◽  
◽  
Sara Mogharrabi ◽  
Samane Jalali ◽  
Asadallah Ahmadzadeh ◽  
...  

Purpose: Two important factors in dental prosthesis are making an accurate impression and producing a suitable cast which represents the exact relationship between prepared tooth and oral structures. This study, aimed to investigate the effects of different combinations of impression and pouring materials on marginal and internal adaptation of premolar zirconia crowns. Material and Methods: Forty maxillary premolars were prepared considering round shoulder finish line. The impressions were made either by additional (Panasil) or condensation (Speedex) silicon, and poured by two different types of gypsum materials (Siladent or GC gypsum) (N=10). Zirconia crowns were fabricated using a CAD-CAM system. The crowns were cemented, and the samples were cut in bucco-lingual direction. Marginal and internal gaps were measured by stereomicroscope (×25). Results: The mean marginal gaps for Pansil-Siladent, Panasil-GC, Speedex-Siladent, and Speedex-GC were 141 μm, 143 μm, 131 μm, and 137 μm respectively. The internal gaps were 334 μm, 292 μm, 278 μm, and 257 μm respectively. The independent T-Student test showed no significant differences in average marginal or internal gap among various impression and gypsum materials or their interactions (p>0.05). Two-way ANOVA test showed no significant differences in maximum marginal or internal gap among various impression and gypsum materials and their interactions (p>0.05). Conclusion: The present study revealed no statistically significant difference in marginal/internal gap among crowns prepared using different combinations of impression-pouring materials evaluated.


Atomic Energy ◽  
1999 ◽  
Vol 87 (1) ◽  
pp. 505-509 ◽  
Author(s):  
F. A. Akopov ◽  
A. A. Akopyan ◽  
B. M. Barykin ◽  
T. I. Borodina ◽  
G. E. Val’yano ◽  
...  

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4311
Author(s):  
Mirza Rustum Baig ◽  
Aqdar A. Akbar ◽  
Munira Embaireeg

A polymer-infiltrated ceramic network (PICN) material has recently been introduced for dental use and evidence is developing regarding the fit accuracy of such crowns with different preparation designs. The aim of this in vitro study was to evaluate the precision of fit of machined monolithic PICN single crowns in comparison to lithium disilicate crowns in terms of marginal gap, internal gap, and absolute marginal discrepancies. A secondary aim was to assess the effect of finish line configuration on the fit accuracy of crowns made from the two materials. Two master metal dies were used to create forty stone dies, with twenty each for the two finish lines, shoulder and chamfer. The stone dies were scanned to produce virtual models, on which ceramic crowns were designed and milled, with ten each for the four material–finish line combinations (n = 10). Marginal gaps and absolute marginal discrepancies were evaluated at six pre-determined margin locations, and the internal gap was measured at 60 designated points using a stereomicroscope-based digital image analysis system. The influence of the material and finish line on the marginal and internal adaptation of crowns was assessed by analyzing the data using two-way analysis of variance (ANOVA), non-parametric, and Bonferroni multiple comparison post-hoc tests (α = 0.05). ANOVA revealed that the differences in the marginal gaps and the absolute marginal discrepancies between the two materials were significant (p < 0.05), but that those the finish line effect and the interaction were not significant (p > 0.05). Using the Mann–Whitney U test, the differences in IG for ‘material’ and ‘finish line’ were not found to be significant (p > 0.05). In conclusion, the finish line configuration did not seem to affect the marginal and internal adaptation of PICN and lithium disilicate crowns. The marginal gap of PICN crowns was below the clinically acceptable threshold of 120 µm.


Atomic Energy ◽  
1998 ◽  
Vol 84 (4) ◽  
pp. 256-259 ◽  
Author(s):  
F. A. Akopov ◽  
A. A. Akopyan ◽  
B. M. Barykin ◽  
G. E. Val'yano ◽  
V. N. Mineev ◽  
...  

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