Gingival Tissue Width and Color Changes of Gingival Margin Caused by Restorative Materials, An In Vitro Study

Objectives: To assess and compare color intensity in three gingival widths caused by four restorative materials, trough simulation of the cervical area in porcine models
Methods: Four restorative materials were selected: metal, metal veneered with feldespathic porcelain, zirconia, and zirconia veneered with feldespathic porcelain. In 20 pig jaws, 40 mucoperiosteal flaps were raised, and connective tissue grafts were harvested from the palate of four maxillae to simulate different gingival thicknesses: 1 mm, 1.5 mm and 2 mm. The four specimens were placed under the flaps and 440 photos were taken. The sample was divided in: 40 control photos and 400 photos with the four restorative materials in the three different thicknesses, evaluating both variables independently. The photos were analyzed in Adobe Photoshop CC 2014, the color codes were converted to decimal system and analyzed with Kruskal-Wallis test
Results: There is no significant change in color lightness between the three gingival thicknesses. However, there is significant change in color lightness between the four restorative materials. Metal caused the most prominent color change; and metal veneered with porcelain caused the less prominent change. If gingiva shows 2 mm of thickness or more, we could use any material because there will no be any translucency. this would be useful in restoring dental implants
Conclusions: Restorative materials cause more prominent color change besides gingival thicknesses, and of all materials, metal materials showed the most prominent change. If gingival thickness is wide, any material can be used.