title: Effect of ultrasonic cleaning and air polishing on porcelain labial margin restorations.
abstract: This study examined porcelain labial margins after ultrasonic scaling and air polishing. Thirty metal coupons were covered with 1.5 mm thick shoulder porcelain and cemented to acrylic resin blocks. A reference mark divided each specimen into a "treated" and an "untreated" side. The specimens were treated as three groups with: (1) an air polisher; (2) an ultrasonic scaler, and (3) the ultrasonic scaler and the air polisher. Surface roughness was determined and selected specimens were observed under scanning electron microscope. Surface roughness ranged from 0.37 microns to 1.06 microns for the untreated sides and from 0.86 microns to 2.80 microns for the treated sides. Increases in roughness were 69% for the ultrasonic scaler/air-polisher; 127% for the air polisher, and 162% for the ultrasonic scaler. ANOVA indicated a significant difference between the treatments. Specimens treated with the air polisher or the ultrasonic scaler and air polisher combination were less distorted than those treated with the ultrasonic scaler alone. The data suggested that careless use of an ultrasonic scaler or air polisher could substantially alter porcelain facial margins.
authors.affiliation: Department of Restorative and Prosthetic Dentistry, Ohio State University, College of Dentistry, Columbus.
authors.forename: S G
authors.initials: SG
authors.lastname: Vermilyea
authors.forename: M K
authors.initials: MK
authors.lastname: Prasanna
authors.forename: J R
authors.initials: JR
authors.lastname: Agar
mesh_terms: D000704:Analysis of Variance; D003775:Dental Polishing / Q000379:methods*; D003776:Dental Porcelain; D012534:Dental Scaling / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D016876:Metal Ceramic Alloys; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties
chemical_list: D016876:Metal Ceramic Alloys; D003776:Dental Porcelain