Two Years Retrospective Clinical Study on Metal-Ceramic Prosthodontics
with Chromium-Cobalt-Nickel Alloy
Charvát J.1, Dostálová T.2, Hubálková H.2, Kučerová H.3, Stebel J.2, Hippmann R.2
1Soukromá stomatologická praxe, Statenice 2Stomatologická klinika 1. LF UK a VFN, Praha, přednosta prof. MUDr. J. Mazánek, DrSc.Výzkumný ústav stomatologický, Praha,přednostka doc. MUDr. J. Dušková, DrSc. |
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Summary:
The aim of the study was to evaluate the quality of metal-ceramic reconstruction
fabricated from common metal alloy and ceramic material. In our Republic, this type of
treatment is commonly used in everyday clinical practice.We have evaluated 52 crowns placed in 19 patients (14 women, 5 men). The crowns were fabricated from ceramic material Vita and
chromium-cobalt-nickel alloy. During clinical examination we have concentrated on the following
items: Crown margin placement – parallel with marginal gingiva (34.6%), or placed above
marginal gingiva (65.4%). As for the crown margin placement, no difference between the
vestibular (34.6% and 65.4% respectively) and oral (32.7% and 59.6% respectively) side of
a tooth has been observed. Such crown margin placement is almost totally without risk of
secondary caries development (1.9%). After two years of use the crowns remained mainly intact
(96.2%), only in two cases (3.8%) we have found a crack, but without the metal alloy exposition.
Neither the anatomical shape nor colour of the crowns has changed.We have detected optimum
marginal adaptation in 71.2%, probing revealed impaired marginal integrity in 26.9% of cases,
in one case (1.9%) we have discovered a gap between a crown margin and a tooth neck. In the
scanning electron microscope the crown cusps were formed properly. The ridges were slightly
smoothed out. Vestibular side of the ceramic crown was as smooth as the tooth’s own surface.
It is obvious that after two years of use an abrasion combined with a physiological change of
gingival margin have led to the gap formation and an impaired marginal adaptation of the
crown. The gap width ranges from 45.0 µm to 108.3 µm. On the vestibular side of the crown we
have discovered more serious impairment when compared to the oral side – 89.1 µm (SE 12.1)
and 63 µm (SE 7.0) respectively. The difference is statistically significant.
Key words:
dentistry – prosthetics – crown – metal-ceramics – chromium-cobalt-nickel alloy.
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