Effect of blood contamination on the shear bond strength at resin/dentin interface in primary teeth.
OBJECTIVE
To assess in vitro the shear bond strength at the resin/dentin interface in primary teeth after contamination with fresh human blood.


METHODS
75 crowns of primary molars were embedded in acrylic resin and mechanically ground to expose a flat dentin surface. The specimens were randomly assigned to five groups (n=15), according to the surface treatment. Group 1 (control) had no blood contamination. The other groups were blood-contaminated and subjected to different post-contamination protocols: in Group 2, the surfaces were rinsed with water; in Group 3, the surfaces were air-dried; in Group 4, the surfaces were rinsed and air-dried; and in Group 5, no post-contamination treatment was done. In all groups, a 3-mm dentin bonding site was demarcated, Single Bond adhesive system was applied and resin composite cylinders were bonded. After 24 hours in distilled water, shear bond strength was tested at a crosshead speed of 0.5 mm/minute.


RESULTS
Means (in MPa) were: Group 1: 7.1 (+/- 4.2); Group 2: 4.0 (+/- 1.8); Group 3: 0.9 (+/- 0.7); Group 4: 3.9 (+/- 2.2) and Group 5: 1.3 (+/- 1.5). Data were analyzed statistically by the Kruskal-Wallis test at 5% significance level. Groups 2 and 4 were similar to each other (P > 0.05) and both ware similar to Group 1 (P > 0.05). These groups (2, 3 and 4) had statistically significantly higher bond strengths than Groups 3 and 5 (P < 0.05). Blood contamination negatively affected the shear bond strength to primary tooth dentin. Among the blood-contaminated groups, water-rinsed specimens had higher bond strengths than those that were exclusively air-dried or not submitted to any post-contamination protocol before adhesive application.
Raffaini
Maria Stella
MS
Department of Pediatric Clinics, Preventive and Social Dentistry, University of São Paulo, Ribeirão Preto, SP, Brazil. msggr@forp.usp.br
Gomes-Silva
Jaciara Miranda
JM
Torres-Mantovani
Carolina Paes
CP
Palma-Dibb
Regina Guenka
RG
Borsatto
Maria Cristina
MC
D000268:Adhesiveness; D000388:Air; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D001769:Blood; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D003890:Desiccation; D006801:Humans; D008422:Materials Testing; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014094:Tooth, Deciduous / Q000648:ultrastructure*; D014867:Water / Q000737:chemistry
D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate