Influence of Different Luting Agents on the Marginal Discrepancy of Procera® AllCeram Alumina Crown Copings – An Experimental Study

Abstract

Summary: Two maxillary first molars and two central incisor typhodont teeth were prepared with 0.8 mm chamfer, 2.0 mm occlusal reduction, and 6 degree taper. The prepared teeth were duplicated 9 times to obtain 36 die stone models and divided into three groups (n = 12). Luting agents tested were zinc phosphate, glass ionomer and resin cement. Procera ® AllCeram 0.6 mm coping was fixed with a calibrated finger force of 50 N. The absolute marginal discrepancy was measured using the scanning electron microscope on four axial walls with 4 measurements on each wall to obtain a total of 16 readings for one tooth. Mann Whitney U test was applied to find significant differences between luting cements and Kruskal Wallis tests among groups. Results The absolute marginal discrepancies of cements were in reducing order zinc phosphate (AZ) 53 μm; resin (AR) 44.5 μm, glass ionomer (AG) 29 μm. There was a significant difference among luting cements AG V/s AZ (p = 0.001) and AR V/s AG (p = 0.003), except AR V/s AZ (p = 0.213). All axial surfaces except mesial showed a significant difference. Conclusion The study concluded that different luting media have a definite effect over the final fit of AllCeram coping. Absolute marginal discrepancy was within the accepted level of 100 μm. Distal axial surface demonstrated a wider gap among all the luting agents.

Effect of Abutment Geometry and Luting Agents on the Vertical Marginal Discrepancy of Cast Copings on Implant Abutments: An In Vitro Study

“…In the present study, cast copings cemented with zinc phosphate showed significantly higher VMD values. These results are according to those of previous studies [ 20 , 21 ] which concluded that zinc phosphate cement showed the highest film thickness compared with glass ionomer and polycarboxylate and may be attributed to its increased viscosity. Abutment geometry and luting agent statistically influenced the VMD of the evaluated cast copings.…”

Effect of Different Types of Luting Cements on Retention and Marginal Adaptation of Implant-Supported Crowns (An in Vitro Study)

“…The marginal accuracy of the cemented crown is of clinical importance and influences long-term survival of the restorations (20) . Marginal fit of complete crown restorations and different cementation techniques influence definitive seating of the cemented prosthesis affecting not only periodontal status but also longevity (21) .The luting agents may influence the marginal discrepancy values by elevating the crown after cementation (22) .In this study, zinc phosphate had a larger mean marginal gap than the other three types of cements.…”

“…Hence, various values have been proposed in the literature as the maximally acceptable marginal gap (20) Heba Mohamed Ahmed, et al…”