Effect of manufacturing protocol on the internal fit and marginal discrepancy of metal ceramic and full ceramic dental crowns

Katerina V Geshoska,Jagoda Bajevska

doi:10.33320/maced.pharm.bull.2017.63.01.008

Abstract

The accuracy of internal fit and marginal precision plays important role of clinical quality and success of dental crowns. Complications caused by marginal discrepancies such as caries, gingivitis, hypersensitivity are highlighted in dental literature. Despite marginal fit, internal fit and precision have a significant role in the persistence of full ceramic and metal ceramic crowns. As the technology evolves, it’s questionable which impression and manufacturing method is giving most accurate dental crowns. Therefore, the main purpose of this study is to get some information and data about marginal and internal fitting of dental crowns made by conventional, two-phase impression technique with polyvinyl siloxanes, and using different manufacturing process. Keywords: internal fit, marginal discrepancy, metal ceramic, full ceramic crowns

Highlights

Precision of internal and marginal gap (MG) plays an important role in the accuracy and success of dental crowns (White et al, 1994)
In the metal ceramic crowns maximal width (P1) 0.532 mm was in the marginal area, and the E max press crowns had (P4) 0.337 mm in the occlusal space as the maximal width
Measurings of axial space (AS), showed better internal fit in metalceramic crowns compared to others with the means of (P2) and (P6) 0.032 mm and 0.076 mm (Fig. 3)

Summary

Introduction

Precision of internal and marginal gap (MG) plays an important role in the accuracy and success of dental crowns (White et al, 1994). Fixed prosthetic restorations with a poor fitting on prepared tooth are a potential danger, allowing entry and reproduction of oral bacteria that subsequently cause secondary caries and gingivitis (Bader et al, 1991; Knoernschild et al, 2000). Poor internal and MG of fixed prosthetic restorations, is the reason that reduces their resilience and longevity (Tuntiprawon et al, 1995). For many years dental researchеrs examine how the crown fits (Fig. 1). Advances and changes happened in measuring the fit of dental crowns: direct observation, crown sectioning, replica technique, profilometry, image analysis and 3D scanning (Holst et al, 2010; Sorensen et al, 1990). Each method has advantages and disadvantages, but the visual observation is not valid because of subjectivity and tactile sensitivity of the examiner

Objectives

Methods

Results

Discussion

Conclusion