Influence of different surface treatments on marginal adaptation in enamel and dentin.
OBJECTIVE
To compare marginal adaptation in enamel and dentin after different surface treatments before and after long-term simultaneous thermal and mechanical stresses in a mixed Class V restoration.


METHODS
Thirty-six V-shaped mixed Class V cavities were prepared in extracted human molars and treated as follows: group 1: 30 s ozone exposure (Heal Ozone, Kavo); group 2: 20 s air abrasion with 50 microm Al2O3 particles (Dento-prep, Rønvig); group 3: 20 s exposure to 27 microm SiOx powder (RONDOflex, Kavo with CoJet powder, 3M-ESPE); group 4: control (no treatment). Cavities were restored with a light-cured composite material (Tetric Ceram, shade A2, Ivoclar Vivadent) using a self-etching adhesive system (Syntac Clasic, Ivoclar Vivadent) with H3PO4 conditioning of the enamel. Each group was evaluated in respect to marginal adaptation before and after mechanical and thermal loading under simulated dentinal fluid.


RESULTS
Even if loading significantly influenced marginal quality in all groups (paired t-test, p < 0.05), the percentages of "continuous margin" of all groups in enamel ranged between 93.2% and 92.3% before and 84.1% and 76.9% after loading and were not significantly different (ANOVA and Scheffe's post-hoc test, p > 0.05). Continuous margin in dentin ranged from 98.9% to 94.2% before and from 95.9% to 76.4% after loading, and significant differences were observed between groups treated with ozone vs control before and after loading and CoJet vs control group after loading (ANOVA and Scheffe's post-hoc test, p < 0.05).


CONCLUSIONS
Surface treatment with ozone and silica coating may significantly decrease marginal quality in dentin without negatively influencing marginal quality in enamel.
Onisor
Ioana
I
Division of Cariology and Endodontology, School of Dentistry, University of Geneva, Geneva, Switzerland.
Bouillaguet
Serge
S
Krejci
Ivo
I
D000134:Acid Etching, Dental; D000537:Aluminum Oxide; D003188:Composite Resins; D003737:Dental Cavity Preparation / Q000379:methods*; D003743:Dental Enamel / Q000648:ultrastructure; D018772:Dental Marginal Adaptation; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D003804:Dentin / Q000648:ultrastructure; D006358:Hot Temperature; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D010126:Ozone; D019279:Resin Cements; D012822:Silicon Dioxide; D013314:Stress, Mechanical; D013499:Surface Properties
D003188:Composite Resins; D019279:Resin Cements; C078484:Syntac dentine adhesive; C121818:Tetric ceram; D010126:Ozone; D012822:Silicon Dioxide; D000537:Aluminum Oxide