title: Comparison of microtensile bond strength of a resin composite to enamel conditioned by acid etching and Er,Cr:YSGG laser in human primary teeth.
abstract: OBJECTIVE
  This study was designed to compare the bond strength of composite resin restorations on the buccal surface of primary human canine after conditioning by conventional acid etching and Er,Cr:YSGG laser.
  
  
  METHODS
  Twenty sound primary canines were cut buccolingually into two halves and each half was randomly placed in Er,Cr:YSGG laser or acid etch group. The samples in the acid etch group were etched with 37% phosphoric acid for 30 s. The samples in the laser group were prepared by Er,Cr:YSGG laser. The G6-Tips and 600 µm diameter were used with a 1.5 W of power output, pulse duration of 140 µs and repetition rate of 20 Hz. The bonding agent was applied on the buccal surface of each sample and layers of resin composite were placed. The samples' bond strengths were evaluated by a microtensile test instrument.
  
  
  RESULTS
  The mean of microtensile bond strength was 18.55±6.41 in the laser group and 24.62±5.56 in acid etch group. Microtensile bond strength achieved by laser conditioning was significantly lower than microtensile bond strength achieved by the conventional acid etching. Statistics To compare the results between the acid etch and laser group, the paired t test was performed (p value<0.001).
  
  
  CONCLUSIONS
  Conditioning enamel in primary teeth by Er,Cr:YSGG laser, cannot be used as an alternative method for acid etching and cannot substitute this conventional method.
authors.affiliation: Department of Paediatric Dentistry, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: B
authors.initials: B
authors.lastname: Malekafzali
authors.forename: R
authors.initials: R
authors.lastname: Fekrazad
authors.forename: A
authors.initials: A
authors.lastname: Mirfasihi
authors.forename: S
authors.initials: S
authors.lastname: Saedi
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D003188:Composite Resins / Q000737:chemistry*; D003481:Cuspid / Q000648:ultrastructure; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D045662:Dental Etching / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D053844:Lasers, Solid-State; D008422:Materials Testing; D010756:Phosphoric Acids / Q000737:chemistry; D011829:Radiation Dosage; D011897:Random Allocation; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D013997:Time Factors; D014094:Tooth, Deciduous / Q000648:ultrastructure*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D010756:Phosphoric Acids; C030242:phosphoric acid