COMPARISON OF BOND STRENGTHS OF DENTURE BASE RESINS TO NICKEL-CHROMIUM-BERYLLIUM REMOVABLE PARTIAL DENTURE ALLOY

Purpose. In vitro bond strengths of a traditional denture base resin ( Lucitone 199) and three adhesive denture base resins (Meta-Dent, Meta- Fast with liner, and Meta-Fast without liner) to treated nickel-chromi um-beryllium (Ni-Cr-Be) partial denture alloy were tested with four al loy surface pretreatments (sandblast, Met-etch, Rocatec with silane, a nd Rocatec without silane), with or without primer (Dentsply). The Luc itone 199 resin bonded to the nonprimed sandblasted group was the cont rol group. The hypothesis was the use of alloy pretreatments and/or pr imer does not improve the bond strength of denture base resins to sand blasted Ni-Cr-Ee partial denture alloy. Material and methods, Primed a nd nonprimed bonded specimens were prepared and finished, stored in 37 degrees C distilled water for 24 hours, then debonded in tension on a testing machine. The bond strength was calculated in megapascals (MPa ). Five specimens were prepared and tested for each experimental condi tion, both with and without primer, for a total of 160 specimens. Resu lts, For three-way analysis of variance, the main effects of resins an d treatment were statistically significant (p < 0.05), but the main ef fect of primer was not statistically significantly (p > 0.05). Without primer, the control group had the lowest bond strength (0 MPa). The t hree adhesive resin groups produced significantly higher bond strength s than the Lucitone resin groups. For the treated groups, nearly all s andblasted groups produced significantly lower bond strength than the other three treated groups. Meta-Dent to Met-etch treated group had th e highest bond strength (23.9 MPa). With primer, the bond strengths of the Lucitone resin groups were significantly higher than the nonprime d groups, and the Lucitone resin-primed Rocatec treated group had the highest bond strength (14.8 MPa). For the three adhesive denture base resins, nearly all primed treated groups had significantly lower bond strengths than nonprimed groups. Conclusions, Without primer, the Luci tone resin-sandblast treated group (control) had the lowest bond stren gth (0 MPa). The Meta-Dent denture base resin with the Met-etch treate d group had the highest bond strength (23.9 MPa). With primer, the Luc itone resin-primed Rocatec-silane treated group had the highest bond s trength (14.8 MPa). For the adhesive denture base resins, nearly all b ond strengths of the primed treated groups were significantly lower th an the values of the nonprimed groups.