Porcelain surface alterations and refinishing after use of two orthodontic bonding methods.
OBJECTIVE
To compare porcelain surfaces at debonding after use of two surface preparation methods and to evaluate a method for restoring the surface.


METHODS
Lava Ceram feldspathic porcelain discs (n = 40) underwent one of two surface treatments prior to bonding orthodontic brackets. Half the discs had sandblasting, hydrofluoric acid, and silane (SB + HF + S), and the other half, phosphoric acid and silane (PA + S). Brackets were debonded using bracket removing pliers, and resin was removed with a 12-fluted carbide bur. The surface was refinished using a porcelain polishing kit, followed by diamond polishing paste. Measurements for surface roughness (Ra), gloss, and color were made before bonding (baseline), after debonding, and after each step of refinishing. Surfaces were also examined by scanning electron microscopy (SEM). Data was analyzed with 2-way ANOVA followed by Tukey HSD tests (alpha = 0.05).


RESULTS
The SB + HF + S bonding method increased Ra (0.160 to 1.121 microm), decreased gloss (41.3 to 3.7) and altered color (DeltaE = 4.37; P < .001). The PA + S method increased Ra (0.173 to 0.341 microm; P < .001), but the increase in Ra was significantly less than that caused by the SB + HF + S bonding method (P < . 001). The PA + S method caused insignificant changes in gloss (41.7 to 38.0) and color (DeltaE = 0.50). The measurements and SEM observations showed that changes were fully restored to baseline with refinishing.


CONCLUSIONS
The PA + S method caused significantly less damage to porcelain than the SB + HF + S method. The refinishing protocol fully restored the porcelain surfaces.
Oregon Health & Science University, Portland, OR 97239, USA.
Drew T
DT
Herion
Jack L
JL
Ferracane
David A
DA
Covell
D000134:Acid Etching, Dental; D000538:Aluminum Silicates / Q000737:chemistry; D002244:Carbon / Q000737:chemistry; D003116:Color; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D017005:Dental Debonding / Q000295:instrumentation; D045662:Dental Etching; D003775:Dental Polishing / Q000379:methods*; D003776:Dental Porcelain / Q000737:chemistry*; D018130:Diamond / Q000737:chemistry; D006801:Humans; D006858:Hydrofluoric Acid / Q000737:chemistry; D049449:Luminescence; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D017680:Potassium Compounds / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D012821:Silanes / Q000737:chemistry; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
D000538:Aluminum Silicates; D003188:Composite Resins; D010756:Phosphoric Acids; D017680:Potassium Compounds; D019279:Resin Cements; D012821:Silanes; C516047:Transbond XT Light Cure Adhesive Primer; D014867:Water; D003776:Dental Porcelain; C016447:feldspar; D002244:Carbon; D018130:Diamond; C030242:phosphoric acid; D006858:Hydrofluoric Acid