RESUMEN
STATEMENT OF PROBLEM: The effect of the surface treatment of zirconium oxide posts on their push-out bond strength is controversial. PURPOSE: The purpose of this study was to compare the effects of 2 surface treatments on the bond strength of zirconium oxide posts cemented with different cements and to assess the failure mode. MATERIAL AND METHODS: Seventy extracted human teeth were divided into 7 groups (n=10). Custom zirconium oxide posts (Cercon; Degudent) were fabricated for 6 groups. Posts in 3 groups were airborne-particle abraded (A). Posts in the other 3 groups were tribochemical silica coated (T). Three cements were used. Zinc phosphate cement was used to cement the zirconium oxide posts in groups AZ and TZ, RelyX ARC cement was used in groups ARA and TRA, and RelyX Unicem cement was used in groups ARU and TRU. Group C contained custom metal posts cemented with zinc phosphate cement. Specimens were horizontally sectioned into 3 sections and subjected to a push-out test. A mixed model analysis of variance, 1-way ANOVA, and the Tukey multiple comparison tests were used for statistical analysis. RESULTS: The highest push-out bond strength was recorded for Group ARU (21.03 MPa), and the lowest was recorded for Group ARA (7.57 MPa). No significant difference in push-out bond strength was found among the different surface treatments and root regions (P>.05). The type of cement had a significant effect on the push-out bond strength of zirconium oxide posts (P=.049). RelyX Unicem cement recorded (19.57 ±8.83 MPa) significantly higher push-out bond strength compared with zinc phosphate (9.95 ±6.31 MPa) and RelyX ARC cements (9.39 ±5.45 MPa). Adhesive failure at the post-cement interface was recorded for 75% of the posts cemented with zinc phosphate and RelyX ARC cements, while mixed failure was recorded for 75% of the posts cemented with RelyX Unicem cement. CONCLUSIONS: The type of cement used resulted in a statistically significant difference in the push-out bond strength of zirconium oxide posts, while both the surface treatment and root region resulted in no statistically significant effect after artificial aging. RelyX Unicem cement had significantly higher push-out bond strength than did zinc phosphate and RelyX ARC cements.
Asunto(s)
Recubrimiento Dental Adhesivo , Cementos Dentales/química , Materiales Dentales/química , Técnica de Perno Muñón/instrumentación , Circonio/química , Bisfenol A Glicidil Metacrilato/química , Aleaciones de Cromo/química , Grabado Dental/métodos , Análisis del Estrés Dental , Humanos , Ensayo de Materiales , Metacrilatos/química , Microscopía Electrónica de Rastreo , Polietilenglicoles/química , Ácidos Polimetacrílicos/química , Cementos de Resina/química , Silanos/química , Estrés Mecánico , Propiedades de Superficie , Itrio/química , Cemento de Fosfato de Zinc/químicaRESUMEN
OBJECTIVE: The aim of this study was to investigate the effect of different luting agents on the bond strength of zirconium oxide posts in root canals after artificial ageing. MATERIAL AND METHODS: Thirty single-rooted extracted teeth were collected. Post spaces were prepared. Custom milled zirconium oxide posts (Cercon, Degudent) were fabricated. Specimens were divided into 3 groups (n=10), according to the luting agents used: group RA, conventional resin luting agent (RelyX ARC); group RU, self-adhesive resin luting agent (RelyX Unicem); and group Z, zinc phosphate luting agent (DeTrey). Specimens were subjected to thermocycling and water storage at 37°C. Specimens were horizontally sectioned into three sections and subjected to a push-out test with 0.5mm/min crosshead speed. The failure mode was assessed by scanning electron microscopy. Data were analysed by using 2-way ANOVA. RESULTS: The following bond strength values were obtained: group RA - 8.89 MPa, group RU - 10.30 MPa and group Z - 9.31 MPa. There was no significant difference in bond strength among the groups (P=0.500). Adhesive failure mode at the cement/post bonded interface was seen in 100%, 66.67% and 83.3% of examined sections in groups RA, RU and Z, respectively. There was no significant difference in bond strength among different root regions (P=0.367). CONCLUSION: The type of luting agent had no significant effect on the push-out bond strength of zirconium oxide posts after artificial ageing. CLINICAL SIGNIFICANCE: Conventional luting agents, such as zinc phosphate cement, seem to provide comparable retention to resin luting agents for cementing custom milled zirconium oxide posts.