Mona Wolfart1, Stefan Wolfart, Matthias Kern. 1. Department of Prosthodontics, Propaedeutics and Dental Materials, Dental School, Christian-Albrechts-University at Kiel, Germany. mwolfart@proth.uni-kiel.de
Abstract
PURPOSE: The purpose of this in vitro study was to evaluate the influence of cement type and application technique on seating discrepancies and retention forces of noble alloy castings cemented on titanium abutments. MATERIALS AND METHODS: Eugenol-free zinc oxide (Freegenol), zinc phosphate (Harvard), glass ionomer (KetacCem), polycarboxylate (Durelon), and self-adhesive resin (RelyX Unicem) cements were used. The inner surfaces of the castings were either completely coated or half-coated with cement. Abutments were used as delivered with a machined surface for the first part of the study. Groups of 8 castings were cemented in both ways. For the second part of the study, the abutments were air-abraded (aluminum oxide, 50 microm particle size), and groups of 8 completely coated castings were cemented with all cements. Marginal discrepancies were measured before and immediately after cementation. Tensile tests were conducted to measure the retention forces. Statistical analysis was performed with pair-wise comparison using the Wilcoxon rank sum test modified by Bonferroni-Holm. RESULTS: Change in seating discrepancies did not differ significantly among the different application techniques. The median retention forces for completely-coated castings were 177 N for eugenol-free zinc oxide, 346 N for zinc phosphate, 469 N for glass ionomer, 813 N for polycarboxylate, and 653 N for self-adhesive resin. With respect to retention force, 3 significantly different groups (P < .05) were identified: (1) zinc oxide, (2) zinc phosphate/glass ionomer, and (3) polycarboxylate/self-adhesive resin. No differences in retention between the 2 coating techniques were found for any cement. However, air abrading the abutments resulted in increased retention of the castings for some of the cements. CONCLUSIONS: Half-coating of the restorations with cements did not result in reduced retention values compared to the complete coating technique, but air abrasion resulted in increased retention with some cements.
PURPOSE: The purpose of this in vitro study was to evaluate the influence of cement type and application technique on seating discrepancies and retention forces of noble alloy castings cemented on titanium abutments. MATERIALS AND METHODS:Eugenol-free zinc oxide (Freegenol), zinc phosphate (Harvard), glass ionomer (KetacCem), polycarboxylate (Durelon), and self-adhesive resin (RelyX Unicem) cements were used. The inner surfaces of the castings were either completely coated or half-coated with cement. Abutments were used as delivered with a machined surface for the first part of the study. Groups of 8 castings were cemented in both ways. For the second part of the study, the abutments were air-abraded (aluminum oxide, 50 microm particle size), and groups of 8 completely coated castings were cemented with all cements. Marginal discrepancies were measured before and immediately after cementation. Tensile tests were conducted to measure the retention forces. Statistical analysis was performed with pair-wise comparison using the Wilcoxon rank sum test modified by Bonferroni-Holm. RESULTS: Change in seating discrepancies did not differ significantly among the different application techniques. The median retention forces for completely-coated castings were 177 N for eugenol-free zinc oxide, 346 N for zinc phosphate, 469 N for glass ionomer, 813 N for polycarboxylate, and 653 N for self-adhesive resin. With respect to retention force, 3 significantly different groups (P < .05) were identified: (1) zinc oxide, (2) zinc phosphate/glass ionomer, and (3) polycarboxylate/self-adhesive resin. No differences in retention between the 2 coating techniques were found for any cement. However, air abrading the abutments resulted in increased retention of the castings for some of the cements. CONCLUSIONS: Half-coating of the restorations with cements did not result in reduced retention values compared to the complete coating technique, but air abrasion resulted in increased retention with some cements.
Authors: R Ajay; K Suma; Seyed Asharaf Ali; Jambai Sampath Kumar Sivakumar; V Rakshagan; V Devaki; K Divya Journal: J Pharm Bioallied Sci Date: 2017-11
Authors: Albano Porto da Cunha; Glauco Pereira Moysés; Ana Christina Claro Neves; Rafael Pino Vitti; Flávia Cardoso da Rosa Goulart; Laís Regiane da Siva-Concílio Journal: Acta Biomater Odontol Scand Date: 2016-01-26
Authors: Ella A Naumova; Felix Roth; Berit Geis; Christine Baulig; Wolfgang H Arnold; Andree Piwowarczyk Journal: Materials (Basel) Date: 2018-09-28 Impact factor: 3.623