10
|
CERECDOCTORS.COM
|
QUARTER 3
|
2015
| | |
FA S B I N D E R
that was cemented with Multilink and was re-cemented with
no further identified problems. Only one crown cemented with
SpeedCEM presented with evidence of crown fracture without
loss of material at 48 months. It has continued to be observed as it
remains asymptomatic.
Laboratory studies provide useful information that aids in
understanding specificphysical properties of restorativematerials,
however no physical property is predictive for clinical efficacy
and longevity. Clinical studies provide significantly more valuable
information to help guide clinical decisions on application of
restorative materials. Several systematic reviews have documented
excellent clinical performance with lithium disilicate crowns for
up to 10 years of clinical service when the manufacturer’s guide-
lines are followed. And several clinical studies specifically on IPS
e.max CAD document similar excellent clinical results for chair-
side CAD/CAM crowns. As clinicians look to apply e.max CAD in
challenging clinical situations, the higher strength of the material
is a desirable feature. Some clinicians may consider the potential
ability of using it in occlusal thickness less than the recommended
1.5 mm that is required to ensure maximum strength of the crown.
However, in spite of limited laboratory studies that indicate this
may be possible, there is very little clinical data to support this
application. The high strength of the e.max CAD material also
leads some clinicians to select using a non-adhesive cementation
technique with a resin modified glass ionomer cement.
Based on a general perception of the discussion boards at
cerecdoctors.com, this is a relatively common cementation appli-
cation technique for e.max CAD crowns with clinicians anecdot-
ally reporting excellent clinical results. However, to date there
is very limited clinical evidence to support this technique being
equally successful to adhesive cementation of IPS e.max CAD
crowns.
Current clinical evidence provides excellent clinical results for
e.max restorations when used in the recommended dimensions of
minimum of 1.5 mm occlusal thickness, and adhesively bonded to
the tooth preparation.
Clinical studies are generally designed to maximize the poten-
tial clinical outcome of a material or technique, with great effort
and time invested to using the material or technique according
to the manufacturer’s instructions. No clinical study desires for
the discovered outcome to be criticized for failure to follow the
manufacturer’s recommended instructions. And rarely would it
be expected for a manufacturer to suggest recommendations for
a material or technique that may somehow limit the optimum
performance.
Therefore, it may be argued that the results of controlled clin-
ical studies, specifically randomized clinical studies or systematic
reviews, would be documenting the optimum clinical outcomes
while reporting failure mechanisms and potential limitations
for clinical application. The challenge for clinicians is to use this
information to maximum benefit when considering treatment
options for the specific needs of their clinical cases. So the ques-
tion is not really “can” a material or technique be used in a certain
fashion, but rather “will” the material or technique result in the
desired clinical outcome?
For questions and more information, Dr. Fasbinder can be reached at
.
BIBLIOGRAPHY
1 Li RW, ChowTW, Matinlinna JP. Ceramic dental biomaterials and CAD/CAM
technology: state of the art. J Prosthodont Res. 2014 Oct;58(4):208-16.
2 Seghi RR, Daher T, &Caputo A. Relative flexural strength of dental restorative ceramics
Dental Materials, 1990, 6(2) 181-184.
3 Bakeman EM, Rego N, Chaiyabutr Y, Kois JC. Influence of Ceramic Thickness and
CeramicMaterials on Fracture Resistance of Posterior Partial Coverage Restorations.
Oper Dent, 2015, 40-2, 211.
4 Seydler B, Rues S, Müller D, Schmitter M. In vitro fracture load of monolithic lithium
disilicate ceramic molar crowns with different wall thicknesses. Clin Oral Invest (2014)
18:1165–1171.
5 Pieger S, Salman A, Bidra AS. Clinical outcomes of lithiumdisilicate single crowns and
partial fixed dental prostheses: A systematic review. J Prosthet Dent 2014;112:22.
6 Fabbri, G Zarone F, Dellificorelli G, Cannistraro G, De Lorenzi M, Mosca A, Sorrentino
R. Clinical Evaluation of 860 Anterior and Posterior LithiumDisilicate Restorations:
Retrospective Study with aMean Follow-up of 3 Years and aMaximumObservational
Period of 6 Years. Int J Periodontics Restorative Dent 2014;34:165
7 Seydler B, Schmitter M. Clinical performance of two different CAD/CAM-fabricated
ceramic crowns: 2-Year results. J Prosthet Dent. 2015 Apr 30. doi: 10.1016/
j.prosdent.2015.02.016. [Epub ahead of print]
8 Reich S, Schierz O. Chair-side generated posterior lithiumdisilicate crowns after 4 years.
Clin Oral Invest, 2013;17:1765
9 Cortellini D, Canale A. Bonding lithiumdisilicate ceramic to feather-edge tooth
preparations: a minimally invasive treatment concept. J Adhes Dent. 2012 Feb;14(1):7-10.
10 Cortellini D, Canale A, Souza RO, Campos F, Lima JC, OzcanM. Durability andWeibull
Characteristics of LithiumDisilicate Crowns Bonded on Abutments with Knife-Edge
and Large Chamfer Finish Lines after Cyclic Loading. J Prosthodont. 2014 Oct 15.
doi: 10.1111/jopr.12237. [Epub ahead of print]
11 Fasbinder DJ, Dennison JB, Heys D, Neiva GF. Five-year Clinical Evaluation of Lithium
Disilicate Chair-side CAD/CAMCrowns. J Dent Res 2015 (REF info)
So the question is not really “can”
a material or technique be used in
a certain fashion, but rather “will”
the material or technique result in
the desired clinical outcome?
