PROSTHETIC DENTISTRY
PARTIAL CERAMIC CROWNS. ESTHETIC AND TISSUE CONSERVATIVE
RESTORATIONS – PART I: POSTERIOR TEETH
Gottfried Schmalz 1,2a* , Marianne Federlin 1b
Department of Operative Dentistry and Periodontology, Medicine Faculty, University Hospital Regensburg, D-93052 Regensburg, Germany
School o f Dental Medicine (ZMK Bern), University of Bern, CH-3010 Bern, Switzerland
1
2
DMD, PhD, Professor, Dr. h.c.
DMD, PhD, Professor
a
b
Received: October 10, 2017
Revised: October 19, 2017
Accepted: November 29, 2017
Published: November 30, 2017
Academic Editor: Jean-François Roulet, DDS, PhD, Prof hc, Professor, University of Florida, Gainesville, FL, USA
Cite this article:
Schmalz G, Federlin M. Partial ceramic crowns. Esthetic and tissue conservative restorations – Part I: posterior teeth. Stoma Edu J. 2017;4(4):270-281
ABSTRACT
DOI: 10.25241/stomaeduj.2017.4(4).art.4
Background: Partial ceramic crowns (PCCs) are more tooth conservative and potentially less stressful
for the periodontium than full coverage crowns and meet the esthetic demands of patients.
Objective: evidence shall be provided, if PCCs are a reliable treatment option, and under which
conditions.
Data sources: this review is based on own published data and experiences and on a review of the
literature.
Results: Longevity of PCCs is in the range of partial crowns from gold alloys. Failures due to chip
fractures, bulk fractures, or debonding can be avoided/reduced by proper technique. Most clinical
experience exists with leucite reinforced silicate or lithium disilicate ceramics, either pressed or
CAD/CAM processed. Tooth preparation must respect the need for sufficient ceramic thickness of
at least 1.5 mm. Residual buccal or oral cusps of less than 2 mm thickness should be included in
the preparation. Cavity preparation should be defect oriented with few parallel walls as guidance
for placement. Dual curing luting composites together with etch and rinse (E&R) adhesives are
standard. Self-adhesive materials can be used but are sensitive to tooth desiccation before luting.
Clinical experience with new universal adhesives is limited, but available results are promising. Light
curing should be performed by applying 32 J/cm 2 from oral, buccal and occlusal aspects (silicate
based ceramics).
Conclusions: PCCs are a reliable treatment option for extended defects in posterior teeth. Special
guidelines must be followed including sufficient ceramic thickness and proper adhesive technique
to avoid failures.
Keywords: partial crowns, ceramic, light curing, luting composite.
1. Introduction
Modern dentistry offers a large variety of different
treatment modalities for large cavities in posterior
teeth which need replacement of one or more cusps.
Direct restorative techniques employing amalgam
as well as resin-based composites in combination
with the adhesive technique are increasingly being
used in such cases on the one hand. However, on the
other hand, the insertion of full crowns is still a well-
recognized and widely-used procedure. Such full
crowns are mainly fabricated either from gold alloys,
non-precious metals, ceramics or combinations
(metal ceramic crowns). Beside this, so-called partial
crowns made from gold alloys have a long tradition
as tooth tissue conservative alternative to full
crowns, which also imply less stress on the adjacent
periodontium.
Obviously, the esthetic properties of metallic
partial crowns are not meeting our patients’ high
expectations in terms of virtually invisible (i.e.
tooth colored) restorations. Therefore, it has been
proposed to adopt the tissue conservative technique
of metallic partial crowns to tooth colored materials,
especially to ceramics, encouraging the fabrication of
partial ceramic crowns (PCCs). PCCs would allow for
a defect-oriented preparation and a tooth-colored
restoration.
Fig. 1 shows a clinical case, where this technique
was applied in a posterior tooth. Undoubtedly, the
esthetics are pleasing. The question however is, if this
is a reliable method, which can be recommended to
the patients and what features have to be addressed
in order to end up with a predictable treatment
outcome. Here we describe our own experiences
covering the recent 20 years and data from the
literature adressing partial ceramic crowns in
posterior teeth. In part II we concentrate on laminate
veneers.
2. Definitions
A partial crown is defined as a restoration with partial
*Corresponding author:
Professor Dr. Dr. h.c.Gottfried Schmalz, DDS, PhD, Department of Operative Dentistry and Periodontology, University Hospital Regensburg, Franz-Josef-Strauss Allee 11, D-93052 Regensburg, Germany, Tel:
+49-941-944-4980, Fax: +49-941-944-4981, e-mail: [email protected]
270
Stoma Edu J. 2017;4(4): 270-281
http://www.stomaeduj.com