Objectives : To evaluate the effects surface treatments of LAVA Ultimate (3M ESPE) and primer on shear bond to resin cement.
Methods : LAVA Ultimate CAD blocks (HT, A3) were embedded to PMMA and grinded with 500 grit SiC papers. The LAVA specimens were divided each groups (n=10/group) according to treatment and used primer (table 1). All specimens were cemented with RelyX™ Ultimate Adhesive Resin Cement (3M ESPE) but was used either as combination of it own primer or alternatively silane Ceramic Primer (3M ESPE). Both primers were used in treated surface ( Rocasoft or Alox 30 µm) and additionally HF-etching. Stub (Ø 3.6mm) of Relyx cement was bonded to the surface and light cured for two 20 second intervals. After 24 hours of storage at 37◦C, a shear bond test was performed using universal testing machine (Lloyd LK30K,UK) at 1.0 mm/min crosshead speed until debonding. Shear bond fracture surface were analysed and categorized. Statistical analysis was carried using ANOVA (α= 0.05).
Results:
Table 1. Shear bond strengths with tested groups (MPa, Mean (SD)
Treatment\Primer | LAVA Primer | Ceramic primer |
SiC #500 | 12,8 (2.7) | 7,6 (2.3) |
Rocatec | 14,0 (2.4) | 13,6 (2.5) |
Alox | 13,1 (1.3) | 12,6 (2.5) |
HF 5% 1 min | 11,8 (0.7) | - |
HF 5% 5 min | 9,2 (2.1) | - |
ANOVA revealed significant differences (p<0.05) in the shear bond strengths between treatment and primer (p>.05). There was a significant difference in bond strength between SiC group between LAVA and Ceremic primer (p<.05). Also fracture surfaces with SiC and Ceramic primer revealed mostly adhesive fracture pattern on contrary than any other group.
Conclusions: Cementation LAVA Ultimate using RelyX Ultimate resin cement was affected various surface treatments, however conventional treatments seem provided most reliable bonding.