title: Micromorphology analysis and bond strength of two adhesives to Er,Cr:YSGG laser-prepared vs. bur-prepared fluorosed enamel.
abstract: Preservation of enamel during composite veneer restorations of fluorosed teeth could be achieved by conservative preparation with Erbium lasers. This study evaluated the effect of fluorosed enamel preparation with Er,Cr:YSGG vs. conventional diamond bur on the micromorphology and bond strength of a self-etch and an etch-and-rinse adhesives. Er,Cr:YSGG laser or diamond bur preparation was performed on the flattened midbuccal surfaces of 70 extracted human premolars with moderate fluorosis (according to Thylstrup and Fejerskov index, TFI = 4-6). Adper Single Bond (SB) with acid etching for 20 or 40 s and Clearfil SE Bond (SEB) alone or with additional etching was applied in four laser groups. The same adhesive procedures were used in three bur groups except for 40 s of etching along with SB. After restoration, microshear bond strength was measured (MPa). Data were analyzed using ANOVA and Tamhane tests (α = 0.05). Six additional specimens were differently prepared and conditioned for scanning electron microscopy evaluation. The highest and lowest bond strengths were obtained for bur-prepared/SB (39.5) and laser-prepared/SEB (16.9), respectively, with a significant difference (P = 0.001). The different adhesive procedures used associated to two adhesives exhibited insignificantly lower bonding in laser-prepared groups compared to bur-prepared ones (P > 0.05), with the exception of additional etching/SEB, which bonded significantly higher to bur-prepared (36.4) than to laser-prepared enamel (18.7, P = 0.04). Morphological analyses revealed a delicate etch pattern with exposed enamel prisms on laser-prepared fluorosed enamel after acid etching and less microretentive pattern after self-etching primer. The etch-and-rinse adhesive was preferred in the laser-prepared fluorosed enamel in terms of bonding performance.
authors.affiliation: Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Shafiei
authors.forename: Zahra
authors.initials: Z
authors.lastname: Jowkar
authors.forename: Reza
authors.initials: R
authors.lastname: Fekrazad
authors.forename: Abolfazl
authors.initials: A
authors.lastname: Khalafi-Nezhad
mesh_terms: D000328:Adult; D003188:Composite Resins / Q000737:chemistry / Q000627:therapeutic use; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry* / Q000627:therapeutic use; D003743:Dental Enamel / Q000648:ultrastructure*; D003799:Dental Stress Analysis; D009050:Fluorosis, Dental / Q000473:pathology*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D019279:Resin Cements / Q000737:chemistry / Q000627:therapeutic use; D055815:Young Adult
chemical_list: C554641:Adper single bond 2; C438313:Clearfil SE Bond; D003188:Composite Resins; D003738:Dental Cements; C444701:Filtek Z250; D019279:Resin Cements
keywords: Er,Cr:YSGG laser; acid etching; bond strength; fluorosed enamel; scanning electron microscopy