The effect of different adhesives on vinyl polysiloxane bond strength to two tray materials.
BACKGROUND
Although stock trays often provide mechanical retention for elastomeric impression materials, manufacturers typically recommend the use of an adhesive, whether a stock or custom tray is used. Universal adhesives for vinyl polysiloxane (VPS) are used in practice, but comparative bond strengths have not been reported.


OBJECTIVE
The aim of this study was to evaluate the bond of 3 VPS materials with a methylmethacrylate autopolymerizing and a light-polymerizing tray material, using the adhesive recommended by the manufacturer of the impression material, and 2 universal adhesives (paint-on and spray-on).


METHODS
Ten specimens per group, for a total of 180 flat 15 x 15 x 20-mm specimens, were made from the 2 tray materials and finished to 320 grit with silicon carbide paper. Four paint-on adhesives (Coltene, Caulk, Kerr VPS, or universal VPS) and 1 spray-on adhesive (Sili Spray) were applied and dried following manufacturers' instructions or for 10 minutes. Three impression materials, Affinis, Aquasil, and Take I, were automixed and injected into a perforated cylinder positioned in a universal testing machine. Tray specimens were positioned against the open cylinder end in contact with the VPS material. Tensile tests (cross-head speed 5 mm/min) were conducted until adhesive separation failure. Mean values and standard errors of the adhesive strength were recorded in MPa for each material combination. Data were first analyzed with Welch analysis of variance (ANOVA) to determine overall significance, and then with a 3-way ANOVA and the Tukey HSD test to make pairwise comparisons, with alpha=.05 for all testing.


RESULTS
For all impression materials tested, the universal spray-on adhesive consistently demonstrated significantly lower bond strengths than all other adhesives (P<.05). Equivalent or significantly (P<.05) higher bond strength values were found for the universal paint-on adhesive for the 3 impression materials tested.


CONCLUSIONS
The use of GC paint-on universal adhesive provided significantly higher adhesive values than those obtained with the adhesives supplied by the manufacturers of the impression materials tested, with the exception of the Kerr impression and adhesive material combination where no significant differences were found.
Peregrina
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Section of Restorative and Prosthetic Dentistry, College of Dentistry, The Ohio State University, 305 West 12th Avenue, Columbus, OH 43210, USA. peregrina@dentistry.dent.ohio-state.edu
Land
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MF
Wandling
C
C
Johnston
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WM
D000269:Adhesives; D000704:Analysis of Variance; D003760:Dental Impression Materials; D003761:Dental Impression Technique / Q000295:instrumentation*; D003799:Dental Stress Analysis; D008422:Materials Testing; D011145:Polyvinyls; D012833:Siloxanes; D013718:Tensile Strength
D000269:Adhesives; D003760:Dental Impression Materials; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane