IADR Abstract Archives
Cleaning Protocols Influence on Bond Strength to Saliva-contaminated Glass-ceramics
Objectives: The aim was to evaluate the effect of saliva contamination and cleaning protocols on bond strength between resin cement and glass ceramics.
Methods: Slices of lithium disilicate and feldspathic ceramic were embedded in acrylic resin, polished, etched with HF 5% for 20s and 60s respectively, and distributed into groups according to cleaning protocols and saliva contamination: SA (silane, saliva, water); WA (saliva, water, silane); AL (saliva, ethanol 70%, silane); PA (saliva, H3PO4 35%, silane); IC (saliva, cleaning paste, silane), CT (just silane, no contamination), NEG (saliva, silane). All groups, except CT were immersed in saliva for 60s, water sprayed and air-dried; NEG was not water sprayed, just air-dried. Then for all groups, an adhesive was applied. Starch tubes (Ø 0.78mm) were filled with a resin cement, positioned on the ceramic surface and light-cured. 32 specimens were produced for each group/ceramic combination. Half of specimens were stored in deionized water (37°C for 24h) and the other half underwent 5000 thermocycles (5-55°C). Microshear bond strength testing was performed and data were analyzed using two-way ANOVA (α=0.05). Fracture patterns were observed using confocal microscope. Additional specimen surfaces were evaluated using SEM and EDX.
Results: For lithium disilicate ceramic, there were no significant differences between cleaning protocols (p=0.39) or effect of thermocycling (p=0.86), the most common fracture pattern was adhesive. For feldspathic ceramic, there were no significant differences between cleaning protocols (p=0.56), but there was effect of thermocycling (p=0.03). There was bond strength reduction at groups CT and WA, after thermocycling. Feldspathic ceramic obtained adhesive, mixed and cohesive in ceramic fractures. EDX and SEM showed no relevant differences in topography and chemical distribution between control, cleaning groups and saliva contamination in both ceramics.
Conclusions: Saliva contamination and cleaning protocols did not influence bond strength between glass ceramics and resin cement.
Methods: Slices of lithium disilicate and feldspathic ceramic were embedded in acrylic resin, polished, etched with HF 5% for 20s and 60s respectively, and distributed into groups according to cleaning protocols and saliva contamination: SA (silane, saliva, water); WA (saliva, water, silane); AL (saliva, ethanol 70%, silane); PA (saliva, H3PO4 35%, silane); IC (saliva, cleaning paste, silane), CT (just silane, no contamination), NEG (saliva, silane). All groups, except CT were immersed in saliva for 60s, water sprayed and air-dried; NEG was not water sprayed, just air-dried. Then for all groups, an adhesive was applied. Starch tubes (Ø 0.78mm) were filled with a resin cement, positioned on the ceramic surface and light-cured. 32 specimens were produced for each group/ceramic combination. Half of specimens were stored in deionized water (37°C for 24h) and the other half underwent 5000 thermocycles (5-55°C). Microshear bond strength testing was performed and data were analyzed using two-way ANOVA (α=0.05). Fracture patterns were observed using confocal microscope. Additional specimen surfaces were evaluated using SEM and EDX.
Results: For lithium disilicate ceramic, there were no significant differences between cleaning protocols (p=0.39) or effect of thermocycling (p=0.86), the most common fracture pattern was adhesive. For feldspathic ceramic, there were no significant differences between cleaning protocols (p=0.56), but there was effect of thermocycling (p=0.03). There was bond strength reduction at groups CT and WA, after thermocycling. Feldspathic ceramic obtained adhesive, mixed and cohesive in ceramic fractures. EDX and SEM showed no relevant differences in topography and chemical distribution between control, cleaning groups and saliva contamination in both ceramics.
Conclusions: Saliva contamination and cleaning protocols did not influence bond strength between glass ceramics and resin cement.