Effect of simulated pulpal pressure on self-adhesive cements bonding to dentin.
OBJECTIVE
To evaluate the bonding effectiveness of self-adhesive luting cements to dentin in the presence of simulated hydrostatic intrapulpal pressure (PP).


METHODS
Thirty composite overlays (Aelite All Purpose Body) were luted to deep-coronal dentin surfaces using four self-adhesive resin cements (Rely X Unicem, G-Cem, Multilink Sprint, Bis-Cem) and one total-etch system (Calibra). Half of the specimens resin cements were applied under a PP of 15 cm H2O. After storage in a moist condition for 1 month (37 degrees C, 100% relative humidity), specimens were sectioned into microtensile beams (1mm2) and stressed to failure with the microtensile bond strength test (microTBS). Data were statistically analyzed with Kruskal-Wallis ranking (p<0.05) and Mann-Whitney tests (p<0.001). The fracture pattern was evaluated under SEM.


RESULTS
Bond strength of Calibra fell significantly when PP was applied during bonding (p<0.05). Rely X Unicem and Bis-Cem performed better under PP. No significant differences for Multilink Sprint and G-Cem bonded specimens were recorded with or without PP.


CONCLUSIONS
Simulated PP influences the adhesive performance of resinous cements. The predominance of acid-base reactions or radical polymerization may explain the different behavior of self-adhesive cements when changing substrate wetness. The application of constant intrapulpal perfusion should be considered when simulating luting procedures in vitro.
Mazzitelli
Claudia
C
Department of Dental Materials and Restorative Dentistry, Policlinico Le Scotte, University of Siena, Viale Bracci, 53100 Siena, Italy.
Monticelli
Francesca
F
Osorio
Raquel
R
Casucci
Alessio
A
Toledano
Manuel
M
Ferrari
Marco
M
D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003782:Dental Pulp / Q000502:physiology*; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D006813:Humidity; D006874:Hydrostatic Pressure; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D010313:Partial Pressure; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors
C485363:Aelite LS; C433205:Calibra; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C528107:G-Cem resin cement; D008689:Methacrylates; D011109:Polymethacrylic Acids; C483701:Rely X Unicem; D019279:Resin Cements; C502351:multilink adhesive system; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; C005044:hydroxyethyl methacrylate