title: Ceramic (Feldspathic & IPS Empress II) vs. laboratory composite (Gradia) veneers; a comparison between their shear bond strength to enamel; an in vitro study.
abstract: Patient demand for aesthetic dentistry is steadily growing. Laminates and free metal restorations have evolved in an attempt to overcome the invasiveness nature of full veneer restorations. Although many different materials have been used for making these restorations, there is no single material that fits best for all purposes. Two groups of ceramic material (Feldspathic and IPS Empress II) and one group of laboratory composite (Gradia) discs (10 discs in each group; 4 mm in diameter and 2 mm in thickness) were prepared according to the manufacturer's instruction. The surface of ceramic discs were etched and silanized. In Gradia group, liquid primer was applied on composite surfaces. Thirty freshly extracted sound human molars and premolars were randomly divided into three groups. The enamel surface of each tooth was slightly flattened (0.3 mm) on the buccal or lingual side and then primed and cemented to the prepared discs with the aid of a dental surveyor. The finishing specimens were thermocycled between 5 degrees C and 55 degrees C for 2500 cycles and then prepared for shear bond strength testing. The resulting data were analyzed by one-way anova and Tukey HSD test. The fractured surfaces of each specimen were inspected by means of stereomicroscope and SEM. There is significant difference between the bond strength of materials tested. The mean bond strengths obtained with Feldspathic ceramic, IPS Empress II and Gradia were 33.10 +/- 4.31 MPa, 26.04 +/- 7.61 MPa and 14.42 +/- 5.82 MPa, respectively. The fracture pattern was mainly mixed for ceramic groups. More scientific evidence needed for standardization of bonding protocols.
authors.affiliation: Department of Fixed Prosthodontics, Faculty of Dentistry, Medical Sciences/University of Tehran, Tehran, Iran.
authors.forename: S
authors.initials: S
authors.lastname: Nikzad
authors.forename: Abbas
authors.initials: A
authors.lastname: Azari
authors.forename: S
authors.initials: S
authors.lastname: Dehgan
mesh_terms: D000134:Acid Etching, Dental; D000268:Adhesiveness; D000537:Aluminum Oxide / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry*; D001641:Bicuspid / Q000648:ultrastructure; D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D002484:Cementation / Q000379:methods; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003743:Dental Enamel / Q000648:ultrastructure*; D003776:Dental Porcelain / Q000737:chemistry*; D003801:Dental Veneers; D006801:Humans; D018020:Lithium Compounds / Q000737:chemistry*; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000648:ultrastructure; D017680:Potassium Compounds / Q000737:chemistry*; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D012821:Silanes / Q000737:chemistry; D017655:Silicon Compounds / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D013997:Time Factors
chemical_list: D000538:Aluminum Silicates; D017554:Carbon Compounds, Inorganic; D003188:Composite Resins; D003738:Dental Cements; C118557:Empress 2; C420130:Excite cement; C470230:Gradia; D018020:Lithium Compounds; D008689:Methacrylates; C076808:Monobond S; D017680:Potassium Compounds; D019279:Resin Cements; D012821:Silanes; D017655:Silicon Compounds; D003776:Dental Porcelain; C016447:feldspar; C103502:Variolink; C005044:hydroxyethyl methacrylate; D000537:Aluminum Oxide; C022088:silicon carbide