Retention and surface changes of zirconia primary crowns with secondary crowns of different materials

Abstract

Despite a lack of knowledge about the aging of zirconia without a veneer layer in the oral environment, zirconia primary crowns are more advantageous in terms of retention force development and wear.

Comparison of Retention Forces of Different Fabrication Methods of Co-Cr Crowns: Pre-sintered and Milled, Cast and Electroforming Secondary Crowns with Different Taper Angles

“…There in, the electroplated secondary crowns on their cast primary crowns with a taper angle of 2° showed lower retention force values than the cast secondary gold crowns on their cast primary crowns. This fact reversed in the study just mentioned with in the taper angle groups of 4° and 6° [6], which Türp et al, [25] only partially confirmed. In their the investigated double crown systems consisted of gold alloy primary crowns with electroformed gold secondary crowns, zirconia primary crowns with electroformed gold secondary crowns and zirconia primary crowns with cast secondary crowns of nonprecious alloy.…”

“…In their the investigated double crown systems consisted of gold alloy primary crowns with electroformed gold secondary crowns, zirconia primary crowns with electroformed gold secondary crowns and zirconia primary crowns with cast secondary crowns of nonprecious alloy. Their system showed decreasing retention force values with an increased taper angle from 2° to 4°, up to 6° [25]. However, the retention force values achieved with electroplated secondary crowns were still sufficient and reproducible [20,26].…”

“…Beueret al, [19] mentioned a negative impact on the retention force due to the chamfer design, which was necessary on the one hand to enable adequate adhesion and to limit, on the other hand, apical positioning. Compared to the milled secondary crowns, the extended hand-made fitting process of the cast secondary crowns, executed by a dental technician, influenced the retention force [6,25]. The chamfer design and the hand-made fitting process seems to have a greater influence on the retention force of 0° taper angle double crowns than the manufacturing process per se.…”

A Systematic Review Studying the Effect of Different Framework Materials on the Retention of Implant Telescopic Overdentures.

“…After initial titles and abstracts screening , 701 irrelevant articles were excluded and a total of 41 articles were selected for full-text screening, 2 additional articles were found through hand searching [4,5] . After full text screening, 15 articles [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] were included in the present analysis.…”

“…Whereas the hardness of 1ry crown (metal) (455.88 HV) is more than that of the 2ry crown (PEEK) (110 HV), therefore, the use of a hard and wear-resistant primary crown material against a less hard secondary crown material is advantageous. Thus, the adaptation between primary and secondary crowns will be achieved by the changes in the fitting surface of the secondary crown [4,5] .…”