TY - JOUR T1 - Influence of polymerization time on properties of dual-curing cements in combination with high translucency monolithic zirconia. JF - J Prosthodont Res Y1 - 2018 A1 - Alovisi, Mario A1 - Scotti, Nicola A1 - Comba, Allegra A1 - Manzon, Elena A1 - Farina, Elena A1 - Pasqualini, Damiano A1 - Michelotto Tempesta, Riccardo A1 - Breschi, Lorenzo A1 - Cadenaro, Milena KW - Composite Resins KW - Dental Bonding KW - Dental Cements KW - Hardness KW - Lansoprazole KW - Materials Testing KW - Polymerization KW - Resins, Synthetic KW - Spectrophotometry KW - Time Factors KW - Zirconium AB -

PURPOSE: The aim of this in vitro study was to assess conversion degree (DC), micro-hardness (MH) and bond strength of two dual-curing resin cements employed under translucent monolithic zirconia irradiated with different time protocols.

METHODS: 84 square shaped samples of 1mm thickness were prepared from high translucency zirconia blocks and divided into two groups (n=24) according to the cement employed: (1) Rely-X Ultimate; (2) Panavia SA. Each group was further divided into 3 subgroups (n=8) according to the irradiation time: (a) no light; (b) 20s; (c) 120s. Light curing was performed 60s after the sample was placed on the diamond support of a FT-IR spectrophotometer with a high power multiLED lamp. Final DC% were calculated after 10min. After 24h, Vickers Test on the cement layer was performed. The same protocol was used to lute composite cylinders in order to evaluate microshear bond-strength test. ANOVA and Bonferroni tests were performed to find differences between MH and bond-strength to zirconia, while for DC% the Scheirer-Ray-Hare two-way test was used.

RESULTS: The two cements reached higher DC% in subgroup (b) and (c). As concern MH, statistics showed an increase in curing time was able to improve MH significantly. Bond-strength was not affected by irradiation time only for Panavia SA.

CONCLUSIONS: The first null hypothesis has to be rejected since DC% and MH of the dual-cements tested were influenced by the curing time. The second null hypothesis is partially rejected since the bond strength was influenced by the curing time only for Rely-X Ultimate.

VL - 62 IS - 4 U1 - http://www.ncbi.nlm.nih.gov/pubmed/29983378?dopt=Abstract ER -