Orthodontic-restorative treatment of chipped or worn incisors.
OBJECTIVE
To evaluate the shear bond strength of esthetic adhesive restorations for worn or fractured incisal edges.


METHODS
On 30 human extracted incisors the edge was reduced and a bevel was prepared in the thickness of enamel. Then, the incisal edges were restored, using a different adhesive system in each of the three groups to which the sample teeth had been randomly assigned. Group A: Scotchbond Multi-Purpose Plus, in combination with phosphoric acid, and Z100 as a restorative material. Group B: Scotchbond 1 after etching with phosphoric acid, plus Z100. Group C: F2000, a compomer, in combination with its Primer/Adhesive. The differences in the bond strength values among the three groups were tested for statistical significance. Also, the resistance to load of the restored teeth was compared with that of 10 intact incisors (Group D) (controls). A statistical analysis was performed to test the significance of the differences.


RESULTS
No statistically significant difference in shear bond strength was found between Scotchbond Multi-Purpose Plus (17.6 MPa) and Scotchbond 1 (14.8 MPa), whereas F2000 gave significantly lower bond strength values (10.1 MPa). As compared with intact incisors, the teeth restored with either Scotchbond Multi-Purpose Plus or Scotchbond 1 did not perform significantly differently under load. On the other hand, the incisors restored with F2000 gave, as compared with the controls, a resistance to loads significantly lower and of a questionable reliability from a clinical standpoint. SEM observations performed on some of the samples revealed that when phosphoric acid was used to condition the substrate, a deep and uniform demineralization of the enamel was effected, and a mechanically retentive interlocking was created at the interface between resin and enamel. The Adhesive/Primer of F2000 was unable to produce an equally retentive morphology.
Goracci
C
C
School of Oral Hygiene, University of Siena, Italy.
Gheewalla
R
R
Kugel
G
G
Ferrari
M
M
D000134:Acid Etching, Dental; D020770:Compomers / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000293:injuries / Q000473:pathology / Q000648:ultrastructure; D003764:Dental Materials / Q000737:chemistry; D003793:Dental Restoration, Permanent / Q000379:methods*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D007180:Incisor / Q000293:injuries / Q000473:pathology / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D009971:Orthodontics, Corrective; D019279:Resin Cements / Q000737:chemistry; D012822:Silicon Dioxide; D013314:Stress, Mechanical; D013499:Surface Properties; D014072:Tooth Abrasion / Q000628:therapy*; D014082:Tooth Fractures / Q000628:therapy*; D015040:Zirconium
D020770:Compomers; D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; C118368:F2000 cement; D005899:Glass Ionomer Cements; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; D012822:Silicon Dioxide; C041330:Scotchbond; D015040:Zirconium