title: Effect of different gutta-percha solvents on the microtensile bond strength of various adhesive systems to pulp chamber dentin.
abstract: OBJECTIVE
  The aim of this study was to evaluate the effect of different endodontic solvents on the microtensile bond strength (μTBS) of various adhesives to pulp chamber dentin.
  
  
  METHODS
  A total of 120 human third molars were selected. Canals were prepared with the ProTaper Universal system and obturated. The access cavities were then restored with resin composite. After 1 week, a retreatment procedure was applied as follows: control, no solvent was applied to the pulp chamber and experimental groups, three different solvents (chloroform, eucalyptol, and orange oil) were applied to the pulp chamber for 2 min. The canal filling was removed and calcium hydroxide (Ca[OH]2) was placed into the canals. After 7 days, the Ca(OH)2was removed from the canals and the canals were re-obturated. Teeth were then divided into three subgroups according to the adhesive used. The samples were restored with a nanohybrid resin composite using three different adhesives: Clearfil SE Bond (CSE), Adper Easy One (AEO), and Single Bond 2 (SB2). The samples were aged with thermocycling. Teeth were sectioned, and a total of 20 dentin sticks were obtained for each subgroup. μTBS testing was then performed. The debonded surfaces were evaluated using scanning electron microscopy (SEM) analysis. Data were analyzed using two-way ANOVA and Tukey's post hoc tests.
  
  
  RESULTS
  Chloroform showed statistically lower mean μTBS values (14 ± 7.2 MPa) than control group did (19.2 ± 6.1 MPa) (p < 0.05). Orange oil (18.1 ± 6.3 MPa) and eucalyptol (16.9 ± 6.8 MPa) did not reduce the mean μTBS statistically (p > 0.05). Chloroform showed significantly lower bond strength for all adhesives (p < 0.05). Whereas orange oil did not reduce the mean μTBS values of all adhesive systems significantly (p > 0.05), eucalyptol reduced the μTBS values of all the groups, but the results were only statistically significant for SB2 (p < 0.05). CSE showed statistically higher bond strength (20.4 ± 6.8 MPa) than AEO (14.6 ± 5.3 MPa) and SB2 (16.3 ± 7.2 MPa) did (p < 0.05). There were no statistical differences between AEO and SB2 (p > 0.05). According to the SEM analysis of the debonded surfaces, adhesive failures were the most common type in all the groups, followed by mixed failures.
  
  
  CONCLUSIONS
  While chloroform reduced the mean bond strength of the adhesive resins, orange oil did not affect the bond strength of the adhesives. The effect of eucalyptol on bond strength depended on the type of adhesive system.
  
  
  CONCLUSIONS
  This study shows that endodontic solvents could affect the microtensile bond strength of adhesives to pulp chamber dentin.
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Sezer
authors.initials: S
authors.lastname: Demırbuga
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Kanşad
authors.initials: K
authors.lastname: Pala
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Erciyes University, Melikgazi, 38039, Kayseri, Turkey. topcuogluhs@hotmail.com.
authors.forename: Hüseyin Sinan
authors.initials: HS
authors.lastname: Topçuoğlu
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Muhammed
authors.initials: M
authors.lastname: Çayabatmaz
authors.affiliation: Department of Pedodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Gamze
authors.initials: G
authors.lastname: Topçuoğlu
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Ebru Nur
authors.initials: EN
authors.lastname: Uçar
mesh_terms: D002725:Chloroform / Q000737:chemistry; D003511:Cyclohexanols / Q000737:chemistry; D003786:Dental Pulp Cavity; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D000077591:Eucalyptol; D006171:Gutta-Percha / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D039821:Monoterpenes / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry; D012389:Root Canal Obturation / Q000379:methods*; D012997:Solvents / Q000737:chemistry; D013718:Tensile Strength
chemical_list: D003511:Cyclohexanols; D017220:Dentin-Bonding Agents; D039821:Monoterpenes; D010938:Plant Oils; D012997:Solvents; D002725:Chloroform; D006171:Gutta-Percha; C087245:orange oil; D000077591:Eucalyptol
keywords: Adhesive; Bond strength; Dentin; Gutta-percha solvent