The effect of various veneering techniques on the marginal fit of zirconia copings

Abstract

PURPOSEThis study aimed to evaluate the fit of zirconia ceramics before and after veneering, using 3 different veneering processes (layering, press-over, and CAD-on techniques).MATERIALS AND METHODSThirty standardized zirconia CAD/CAM frameworks were constructed and divided into three groups of 10 each. The first group was veneered using the traditional layering technique. Press-over and CAD-on techniques were used to veneer second and third groups. The marginal gap of specimens was measured before and after veneering process at 18 sites on the master die using a digital microscope. Paired t-test was used to evaluate mean marginal gap changes. One-way ANOVA and post hoc tests were also employed for comparison among 3 groups (α=.05).RESULTSMarginal gap of 3 groups was increased after porcelain veneering. The mean marginal gap values after veneering in the layering group (63.06 µm) was higher than press-over (50.64 µm) and CAD-on (51.50 µm) veneered groups (P<.001).CONCLUSIONThree veneering methods altered the marginal fit of zirconia copings. Conventional layering technique increased the marginal gap of zirconia framework more than pressing and CAD-on techniques. All ceramic crowns made through three different veneering methods revealed clinically acceptable marginal fit.

A comparative study of marginal fit of copings prepared with various techniques on different implant abutments

“…Some previous studies showed the variations in accuracy between the restorations with and without the porcelain build-up techniques and the significant effects of the veneering techniques on marginal accuracy 50,51) . This investigation, however, did not consider a veneer technique which was one of the limitations.…”

Effect of fabrication stages and cementation on the marginal fit of CAD-CAM monolithic zirconia crowns

“…Veneering may have a significant influence on the marginal fit of zirconia restorations. [43][44][45] However, as monolithic zirconia crowns are not veneered but characterized only with staining through glazing, 46 how the marginal fit of the monolithic zirconia crowns is affected by the fabrication stages is important. Cementation may also affect the marginal fit of ceramic crowns.…”

Effect of Three Veneering Techniques on Marginal Accuracy and Fracture Resistance of Zirconia Base Fixed Restoration (In-Vitro Study).

“…Actually high quality, all-ceramic restorations are not easily distinguished from adjacent natural teeth. 13 Among the many ceramic systems that have been developed, Yttria-stabilized polycrystalline tetragonal zirconia has become a common form of dental restoration; mostly because of having good characteristics including esthetics, excellent biocompatibility, low plaque accumulation, and high strength 14 . In addition to esthetics, marginal fit and fracture strength are essential criteria for clinical success.…”