Sushma Reddy1, Chandrasekharan Nair K2*, Jaykar Shetty3 and Viswanath Gurumurthy4
1Former Reader, Department of Prosthodontics, Narayana Dental College, Nellore,
Andhra Pradesh, India
2Professor Emeritus, Department of Prosthodontics, Sri Sankara Dental College,
Akathumuri, Thiruvananthapuram, Kerala, India
3Former Professor, Department of Prosthodontics, AECS Maaruti College of Dental
Sciences, Bangalore, India
4Associate Professor, Department of Dental Technology, College of Applied Medical
Sciences, King Khalid University, KSA
*Corresponding Author: K Chandrasekharan Nair Professor Emeritus, Department of Prosthodontics, Sri Sankara Dental College, Akathumuri, Thiruvananthapuram, Kerala, India.
Received: March 20, 2023; Published: April 27, 2023
Purpose of the study: Technical and biological acceptance of a fixed dental prosthesis, to a great extent is dictated by the marginal integrity. It is essential to find out the appropriate technique that provides better marginal adaptability for fixed partial denture framework fabricated with different materials and techniques.
Objectives:
To find out and compare
• The effect of conventional and over refractory casting techniques on the marginal fit of fixed partial denture framework.Materials and Methods: A metal model consisting of three full crown preparations was created to simulate a five unit fixed partial denture situation. The metal model was duplicated in dental stone and in refractory investment materials. The stone casts were used for the conventional casting technique and the refractory casts were used for the over refractory technique. In conventional technique wax pattern was removed from the stone cast and invested where as in over refractory cast technique wax pattern was invested along with refractory cast. To compare the casting technique and CAD/CAM technique one zirconia framework was made using CAD/CAM. Castings were seated on the metal die and the marginal gap was measured under stereo microscope. Data was statistically analyzed with ANOVA.
Results: In conventional technique the mean marginal gap values obtained were - for Nickel chromium (78.21μm ± 4.45μm), Commercially pure Titanium (60.51 μm ± 3.04 μm) and lithium disilicate-pressable Ceramic (39.70 μm ± 3.51μm). In over refractory technique the mean marginal gap values obtained were - for Nickel chromium (39.48 μm ± 3.90 μm), Commercially pure Titanium (31.15 μm ± 2.08 μm) and lithium di silicate-pressable Ceramic (21.28 μm ± 2.48 μm). The marginal gap value obtained for Zirconia with CAD/CAM technique was 16.92 μm ± 2.65 μm. Statistical analysis showed that the effect of conventional casting technique, over refractory casting technique and CAD/CAM technique were statistically significant.
Conclusions • Over refractory technique showed lesser marginal gap when compared to that of Conventional technique. • Among the materials used for castings the highest gap was seen in Nickel Chromium followed by Commercially pure Titanium and then by pressable Ceramic both in Conventional and Over refractory techniques.
Keywords:Ameloblastoma; Unicystic Ameloblastoma; Genetic Mutation
Citation: Sushma Reddy., et al. “A Comparative Study on the Marginal Fit of Fixed Prosthesis Made by Over Refractory Technique, Conventional Technique and CAD-CAM - An Invitro Study".Acta Scientific Dental Sciences 7.5 (2023): 44-53.
Copyright: © 2023 Chandrasekharan Nair K., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
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