In vitro color changes of soft tissues caused by restorative materials.
A crucial factor influencing implant esthetics is the color of the peri-implant mucosa. This in vitro study analyzed the effect of titanium and zirconia with and without veneering ceramic on the color of mucosa of three different thicknesses. Ten pig maxillae were used, and the palatal area was chosen as the test region. To simulate different mucosa thicknesses, connective tissue grafts, 0.5 mm and 1.0 mm thick, were harvested from three additional jaws. Defined mucosa thicknesses were created by placing the grafts under a palatal mucosa flap. Four different test specimens (titanium, titanium veneered with feldspathic ceramic, zirconia, and zirconia veneered with feldspathic ceramic) were placed under the mucosa, and the color of the tissue was evaluated with a spectrophotometer for three different soft tissue thicknesses (1.5, 2.0, and 3.0 mm). The color was compared to mucosa without test specimens, and the color difference (DeltaE) was calculated. All restorative materials induced overall color changes (DeltaE), which diminished with increases in soft tissue thickness. Titanium induced the most prominent color change. Zirconia did not induce visible color changes in 2.0-mm-thick and 3.0-mm-thick mucosa, regardless of whether it was veneered. However, with a mucosa thickness of 3.0 mm, no change in color could be distinguished by the human eye on any specimen. Mucosa thickness is a crucial factor in terms of discoloration caused by different restorative materials. In patients with thinner mucosa, zirconia will show the least color change.
Jung
Ronald E
RE
Clinic for Fixed and Removable Prosthodontics and Dental Material Science, University of Zurich, Switzerland. jung@zzmk.unizh.ch
Sailer
Irena
I
Hämmerle
Christoph H F
CH
Attin
Thomas
T
Schmidlin
Patrick
P
D000818:Animals; D003116:Color; D003776:Dental Porcelain / Q000009:adverse effects; D003793:Dental Restoration, Permanent / Q000009:adverse effects*; D003801:Dental Veneers / Q000009:adverse effects; D009061:Mouth Mucosa / Q000187:drug effects*; D010858:Pigmentation / Q000187:drug effects*; D013053:Spectrophotometry; D034421:Sus scrofa; D013552:Swine; D014025:Titanium / Q000009:adverse effects; D015040:Zirconium / Q000009:adverse effects
D003776:Dental Porcelain; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide