title: Marginal sealing ability of silorane and methacrylate resin composites in class II cavities: A scanning electron microscopic study.
abstract: OBJECTIVE
  To comparatively evaluate the microleakage and microgap formation along the gingival margin in class II cavities restored with silorane resin composite and methacrylate resin composite with and without flowable resin liner.
  
  
  METHODS
  Sixty human mandibular premolars were distributed into three groups, each group containing 20 teeth (n = 20). Mesial (subgroup A) and distal (subgroup B) box cavities were prepared with gingival margin above and below cemento enamel junction (CEJ), respectively, in each tooth and restored as follows - Group I - Silorane resin composite with self-etch primer and bond (Filtek P90, 3M ESPE MN, USA). Group II - Methacrylate resin composite (Filtek P60, 3M ESPE MN, USA) and self-etch adhesive (Adper Easy one, 3M ESPE MN, USA). Group III - Methacrylate resin composite with self-etch adhesive and a flowable resin liner (Filtek Z350 XT, 3M ESPE MN, USA). The teeth were thermocycled and immersed in 50% silver nitrate solution before sectioning. The specimens were observed under scanning electron microscope for dye penetration and microgap formation. The data was subjected to statistical analysis using Kruskal-Wallis test and Mann-Whitney U test using SPSS version 18.
  
  
  RESULTS
  Subgroup A in all the three groups showed significantly less microleakage and microgap formation compared to subgroup B with P < 0.05. Intergroup comparison of subgroup A did not show statistically significant difference, whereas subgroup B showed statistically significant difference for microleakage between group I and group II (P = 0.003), group III and group II (P = 0.002).
  
  
  CONCLUSIONS
  Silorane resin composite and methacrylate resin with liner showed significantly less microleakage in class II cavities along the gingival margin placed below CEJ compared to methacrylate resin without liner. All the study groups showed less microleakage and microgap formation along the gingival margin placed above CEJ.
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sri Siddhartha Dental College, Tumkur, Karnataka, India.
authors.forename: Jyothi Kashi
authors.initials: JK
authors.lastname: Nanjundasetty
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sri Siddhartha Dental College, Tumkur, Karnataka, India.
authors.forename: Soumyaranjan
authors.initials: S
authors.lastname: Nanda
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sri Siddhartha Dental College, Tumkur, Karnataka, India.
authors.forename: Venugopal
authors.initials: V
authors.lastname: Panuganti
authors.affiliation: Department of Conservative Dentistry and Endodontics, Sri Siddhartha Dental College, Tumkur, Karnataka, India.
authors.forename: Jayashankar Chatra
authors.initials: JC
authors.lastname: Marigowda
keywords: Flowable resin liner; methacrylate resin; microgap; microleakage; scanning electron microscope; silorane resin