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Effect of finish line steepness and construction technique on vertical marginal gap distance of machinable and pressable IPS e-max ceramic copings : An in-vitro study

Thesis

Last updated: 06 Feb 2023

Subjects

-

Tags

Fixed Prosthodontics

Authors

Ahmad, Esraa Hashem

Accessioned

2018-08-26 05:26:09

Available

2018-08-26 05:26:09

type

M.Sc. Thesis

Abstract

The aim of this in-vitro study was to assess the effect of finish line steepness (1 and 3 mm) and construction technique ( machinable and pressable ) on the vertical marginal gap distance of the IPS e.max ceramic copings In this study a total of 54 IPS e.max ceramic copings were constructed and divided according to construction technique into two main groups:Group I (n=14): Machinable all ceramic copings (IPS e.max CAD)Group II (n=40): Heat pressed all ceramic copings (IPS e.max Press) Each group was further subdivided into two subgroups according to different finish line steepness: Subgroup 1 : 1-mm finish line steepnessSubgroup 2 : 3-mm finish line steepness Two ivory upper central incisors with same dimensions were selected, mounted in a stone base and prepared to receive full coverage all ceramic crowns with the two different finish line steepness using dental milling surveyor. Two nickel chromium dies with two different finish line steepnesses were then fabricated by duplication from the two prepared ivory upper central incisors. Machinable and pressable IPS e.max ceramic copings were constructed on these metal dies according to the manufacturer instruction following standardized protocol. For all samples, vertical marginal gap distance was measured at three selected points on the middle third of each surface of the die. The marginal area were photographed under magnification of x40 with digital camera attached to a stereomicroscope which was coupled to a computerized Quantitative analysis system, by means of software. The vertical marginal gap distance was measured in micrometers (µm). Each measurement was repeated three times, with all measurements being performed by a single investigator.Data were collected, tabulated and statistically analyzed.Statistical analysis showed that both finish line steepnesses and construction technique had significant effect on the vertical marginal gap distance of the IPS emax copings as follows:1-Copings with 3 mm finish line steepness recorded statistically significant higher vertical marginal gap distance compared to copings with 1 mm finish line steepness. (P<0.0001)2-Copings constructed by CAD/CAM technology recorded statistically significant higher vertical marginal gap distance compared to copings constructed by Heat pressed technique. (P<0.0001)3-Regarding to the heat pressed technique, copings with 1 mm finish line steepness showed statistically non-significant lower vertical marginal gap distance compared to copings with 3 mm finish line steepness. (P=0.329).

Issued

1 Jan 2016

DOI

http://dx.doi.org/10.21473/iknito-space/39559

Details

Type

Thesis

Created At

28 Jan 2023