Effect of ultrasonic vibration on dentin bond strength and resin infiltration.
OBJECTIVE
To apply a vibration technique to compare the bond strength and resin penetration depth into the dentin tubules with those gained using conventional techniques.


METHODS
Eighty-eight noncarious extracted human permanent molar teeth were sectioned to remove the coronal enamel. They were embedded in a 1-inch PVC pipe with an acrylic resin. The occlusal surfaces were placed so that the tooth and the embedding medium were at the same level to form a single flat surface. The samples were subsequently polished with silicon carbide abrasive papers, and randomly assigned to four groups (n=22). In Groups 1 and 2, Single Bond was used, and in Groups 3 and 4, One-Step was used. Each adhesive system was applied according to its manufacturer's instructions. For Groups 2 and 4, vibration was applied with an ultrasonic scaler for 10 seconds, and the adhesive was light-cured for 10 seconds. The resin composite was condensed onto the prepared surface in two increments using a Teflon mold and each increment was light-cured for 40 seconds. After 24 hours soaking in tap water at room temperature, the specimens were thermocycled, and the shear bond strengths were measured using a universal testing machine. One-way ANOVA test followed by Student-Newman-Keuls test (P < 0.05) were used to analyze the results. To investigate the infiltration patterns of the adhesive materials, the surface of the specimens was examined with electron microscopy.


RESULTS
The shear bond strengths of the vibration groups (Groups 2, 4) were significantly higher than those of the non-vibration groups (Groups 1, 3). The shear bond strengths of Single Bond and One-Step were not significantly different. The vibration groups showed greater numbers of resin tags in the tubules and lateral branches under SEM than the non-vibration groups.
Department of Pediatric Dentistry, College of Dentistry, Seoul National University, Korea.
Jin
J
Lee
Ki-Taeg
KT
Jang
Jung-Wook
JW
Kim
Sang-Hoon
SH
Lee
Se-Hyun
SH
Hahn
Chong-Chul
CC
Kim
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D001840:Dental Bonding / Q000379:methods*; D003799:Dental Stress Analysis; D003806:Dentin Permeability; D017220:Dentin-Bonding Agents; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D008855:Microscopy, Electron, Scanning; D008963:Molar; D011897:Random Allocation; D019279:Resin Cements; D013718:Tensile Strength; D014465:Ultrasonics; D014732:Vibration
C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C115612:single bond; D017438:Bisphenol A-Glycidyl Methacrylate