title: Comparative evaluation of the microtensile bond strength of bulk fill and low shrinkage composite for different depths of Class II cavities with the cervical margin in cementum: Anin vitrostudy.
abstract: OBJECTIVE
  The aim of this study was to evaluate the microtensile bond strength (μTBS) of bulk fill and low shrinkage composite for different depths of Class II cavities with the cervical margin in cementum.
  
  
  METHODS
  Standardized conservative box-shaped Class II cavities were prepared on sixty sound-impacted human third molars. The samples were randomly divided into two groups: Group I (n= 30) - horizontal incremental technique and Group II (n= 30) - bulk fill technique (SonicFill). They were further subdivided into three subgroups of (n= 10) samples each according to the different occluso-gingival height: subgroup (A - 4 mm, B - 5 mm, and C - 6 mm). The gingival margins for all the samples were located 1 mm below the cementoenamel junction. The restored samples were subjected to thermocycling (500 cycles) followed by μTBS testing. The scores were statistically analyzed using ANOVA andpost hoctest using SPSS software version 16.
  
  
  RESULTS
  Subgroups IA and IB showed lower μTBS than subgroups IIA and IIB (P< 0.05) whereas subgroup IC showed higher μTBS than subgroup IIC (P< 0.05). SonicFill showed a significant reduction in μTBS as the depth increased.
  
  
  CONCLUSIONS
  SonicFill should be used in two increments for cavities with a depth of more than 5 mm.
authors.affiliation: Department of Conservative Dentistry and Endodontics, ITS-CDSR, Ghaziabad, Uttar Pradesh, India.
authors.forename: Sonali
authors.initials: S
authors.lastname: Taneja
authors.affiliation: Department of Conservative Dentistry and Endodontics, ITS-CDSR, Ghaziabad, Uttar Pradesh, India.
authors.forename: Pragya
authors.initials: P
authors.lastname: Kumar
authors.affiliation: Department of Conservative Dentistry and Endodontics, ITS-CDSR, Ghaziabad, Uttar Pradesh, India.
authors.forename: Avnish
authors.initials: A
authors.lastname: Kumar
keywords: Bulk fill technique; incremental technique; microtensile bond strength; thermocycling