Factors affecting the bond strength of denture base and reline acrylic resins to base metal materials

J. Appl. Oral Sci. vol.21 no.4 Bauru July/Aug. 2013

ABSTRACT

OBJECTIVE:

The shear bond strengths of two hard chairside reline resin materials and an auto-polymerizing denture base resin material to cast Ti and a Co-Cr alloy treated using four conditioning methods were investigated.

MATERIAL AND METHODS:

Disk specimens (diameter 10 mm and thickness 2.5 mm) were cast from pure Ti and Co-Cr alloy. The specimens were wet-ground to a final surface finish of 600 grit, air-dried, and treated with the following bonding systems: 1) air-abraded with 50-70-µm grain alumina (CON); 2) 1) + conditioned with a primer, including an acidic phosphonoacetate monomer (MHPA); 3) 1) + conditioned with a primer including a diphosphate monomer (MDP); 4) treated with a tribochemical system. Three resin materials were applied to each metal specimen. Shear bond strengths were determined before and after 10,000 thermocycles.

RESULTS:

The strengths decreased after thermocycling for all combinations. Among the resin materials assessed, the denture base material showed significantly (p<0 .05="" 10="" 34.56="" 38.30="" after="" alloy.="" and="" base="" bond="" both="" cast="" co-cr="" con="" condition.="" decreased="" denture="" except="" for="" greater="" less="" material="" materials="" mdp="" metals.="" mpa="" of="" p="" reline="" shear="" strengths="" sufficient:="" than="" the="" thermocycles="" ti="" to="" two="" were="" with="">

CONCLUSION:

Bonding of reline resin materials to metals assessed was clinically insufficient, regardless of metal type, surface treatment, and resin composition. For the relining of metal denture frameworks, a denture base material should be used.