Bond strength of maxillofacial silicone to various three-dimensional printing resins compared to conventional substructures.

BACKGROUND

Bonding between silicone elastomers and rigid substructures is critical to clinical success of extraoral maxillofacial prostheses. This study aimed to investigate the bond strength of silicone elastomers to conventional and alternative 3-dimensional printing resin materials and the effect of artificial aging.

METHODS

The bond strength of seven resin substructure materials to a maxillofacial silicone was tested using the 180° peel test without artificial aging and after artificial aging in 14 groups. Test specimens composed of a silicone elastomer bonded to a substructure which were prepared according to ASTM D903-98 standard. A total of 70 specimens were prepared with a maxillofacial silicone bonded with a primer to substructures made of chemically polymerized clear acrylic, heat-polymerized clear acrylic and heat-polymerized pink acrylic, 3-dimensional surgical guide, 3-dimensional denture base, 3-dimensional polyetherketoneketone, and 3-dimensional polyetheretherketone resins (n = 10). Half of the specimens (n = 5 per group) were aged in an environmental chamber (Ci4400 Weather-Ometer, Atlas, Inc., USA) to assess the impact of 360 h of accelerated artificial aging. Peel bond strength values were analyzed using two-way ANOVA and post-hoc comparisons with Bonferroni correction (α = 0.05). Bond failures were classified using confocal microscopy.

RESULTS

Substructure material, artificial aging, and their interaction significantly affected peel bond strength (p < 0.001). Polyetherketoneketone and polyetheretherketone exhibited significantly lower mean bond strength in non-aged groups (p < 0.05). Within the aged groups, surgical guide and denture base resins demonstrated significantly higher bond strength (p < 0.05). The most common failure type was mixed (71.4%), followed by adhesive (20%), cohesive (9%).

CONCLUSIONS

Three-dimensional printed surgical guide resin and denture base resin specimens showed higher mean bond strength after artificial aging compared to commonly used conventional resin substructures and three- dimensional printed polyetherketoneketone and polyetheretherketone.