Variables affecting silicone-polymethyl methacrylate interfacial bond strengths.
OBJECTIVE
This study investigated the effects of various polymerization methods and of various types of silane coupling agents on the interfacial bond strengths of Molloplast-B and of two types of heat-processed polymethyl methacrylate (PMMA).


METHODS
Standardized blocks of PMMA were processed and stored in 100% humidity for 14 days. Silicone of equal dimensions was flasked and processed with premixed and fresh-mixed silane coupling agents interposed. Processing utilized both a typical heated-water system and a dry-heat oven. Following recovery, the specimens were peel-tested at an angle of 180 degrees in an Instron machine.


RESULTS
There was no significant difference between the test variables of Lucitone (Dentsply/York Division, York, PA) versus Lucitone 199 (Dentsply/York Division), nor with wet versus dry heat polymerization methods. However, the mean bond strengths for premixed silane improved slightly in a wet polymerization environment. Conversely, fresh-mixed silane's mean bond strength increased slightly with dry-heat polymerization.


CONCLUSIONS
The bond strength between a methyl methacrylate denture base and a silicone soft liner varies only slightly when either Lucitone, Lucitone 199, or polymerization in a wet or dry environment is used. Under the conditions of this study, a fresh-mixed silane coupling agent produced a distinctly superior bond strength.
Department of Graduate Prosthodontics, University of Oklahoma College of Dentistry, Oklahoma City.
W E
WE
Wood
D L
DL
Johnson
M G
MG
Duncanson
D000180:Acrylic Resins / Q000737:chemistry; D000704:Analysis of Variance; D001840:Dental Bonding; D003819:Denture Bases; D003822:Denture Liners; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D008422:Materials Testing; D008768:Methylmethacrylates / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D012826:Silicone Elastomers / Q000737:chemistry; D013718:Tensile Strength
D000180:Acrylic Resins; D004129:Dimethylpolysiloxanes; C020964:MDX 4-4210; D008768:Methylmethacrylates; D012821:Silanes; D012826:Silicone Elastomers; C040291:Lucitone