ORIGINAL RESEARCH PAPER EFFECT OF ANTIOXIDANT ON PULL-OUT BOND STRENGTH OF FIBER POST BONDED WITH SELF-ADHESIVE RESIN LUTING CEMENT Dr. Anam Husain* M.D.S Student, Department of Conservative Dentistry and Endodontics, Subharti Dental College & Hospital, Meerut, Swami Vivekanand Subharti University. *Corresponding Author Dr. Sachin Gupta M.D.S., Professor, Department of Conservative Dentistry and Endodontics, Subharti Dental College & Hospital, Meerut, Swami Vivekanand Subharti University. Dr. Vineeta Nikhil M.D.S., Dean Clinical Affairs, Director PG Studies and Head, Department of Conservative Dentistry and Endodontics, Subharti Dental College & Hospital, Meerut Swami Vivekanand Subharti University Dr. Shikha Jaiswal M.D.S., Professor Department of Conservative Dentistry and Endodontics, Subharti Dental College & Hospital, Meerut, Swami Vivekanand Subharti University. INTRODUCTION Intraradicular posts are often required in endodontically treated teeth presenting with extensive loss of tooth structure due to caries, restorative procedures, fractures and endodontic access preparation. Glass fiber posts, having modulus of elasticity similar to dentin prevent catastrophic failures by providing uniform stress distribution. Good adhesive bond established by resin luting cement at interfaces with the post and the dentin is necessary for the success of fiber post and core assembly. There are various factors affecting bond strength of post to dentin which include dentin surface treatment, type of luting cement used and presence/ absence of smear layer on the dentin surface. Presence of the smear layer may hinder penetration and adaptation of adhesive resin cement inside 1 dentinal tubules, thus affecting bond strength. Irrigation of post space with NaOCl/ EDTA might be considered critical for the removal of smear layer in order to generate effective resin-dentin interface bond. NaOCl may exert a negative effect on bond strength of post to dentin due to presence of nascent oxygen. Sodium ascorbate and many other antioxidants have been used for reversal of deleterious effects caused by NaOCl on the root canal dentin. Use of self-adhesive resin luting cement for luting of posts reduces the steps 2, 3 in bonding and make it user friendly. Various authors reported the bond strengths of self-adhesive resin cements to be satisfactory and comparable to other multistep resin cements. Evaluation of bond strength of Rely X U200 after post space irrigation with various irrigants has not been documented much, therefore present study was carried out to evaluate the effect of post space treatment on pull- out bond strength of RelyX U200 to dentin after treatment with NaOCl, EDTA and sodium ascorbate. Self-adhesive resin cement RelyX U200 is based on phosphoric acid methacrylates which are thought to demineralize and infiltrate the tooth sub s trate resulting in micromechanical retention. Hence the aim of this study was to evaluate the effect of sodium ascorbate on pull-out bond strength of self-adhesive resin cement to root dentin after irrigation of post space with NaOCl. MATERIALS AND METHODS Sixty mandibular premolar teeth extracted for orthodontic reasons with single canal were selected and stored in 0.5% Chloramine T solution (Hi-Media Labs, India). Teeth were decoronated near the cementoenamel junction to obtain a standardized root length of 14 mm. The specimens were instrumented by using ProTaper rotary system (Dentsply, Maillefer Ballaigues, Switzerland) at a working length of 0.5 mm from the apex till F3 rotary file. After each instrumentation, the canals were irrigated with 1 ml of 5% NaOCl (Prime Dental Products Pvt. Ltd, India). Final irrigation was done with 5 ml of 17% EDTA (CanaLarge, Ammdent, Noida, India) for 1 min followed by 5 ml normal saline and dried with corresponding paper points (Dentsply, Maillefer Ballaigues, Switzerland). Obturation was carried out with warm vertical compaction technique using AH Plus sealer (Dentsply, De Trey, Germany) leaving a canal space of 9 mm followed by sealing with Cavit (Ammdent, Saronno-Italia). The obturated samples were stored for 24 hours at 37°C and 100% humidity. Post spaces were prepared using peeso drills (Mani Inc, Japan) sequentially till No. 4 to accommodate the corresponding Reforpost Glass Fiber (Angelus, PR, Brazil). The fit of the post was verified radiographically. Thereafter the prepared samples were randomly distributed into four groups based on the treatment of post spaces: GROUP A: 5 ml of saline along with PUI for 1 min. GROUP B: 5 ml of 17% EDTA along with PUI for 1 min followed by rinsing with 5 ml of saline for 1 min. GROUP C: 5 ml of 5% NaOCl for 1 min followed by 5 ml of 17% EDTA for 1 min along with PUI for both irrigants followed by 5 ml of saline for 1 min. GROUP D: Samples of group D were treated similar to group C followed by irrigation with 10% sodium ascorbate solution (Now Foods, 395 S. Glen Ellyn Rd. Bloomingdale, IL 60108, USA) at the rate of 1 min per ml for 10 mins without PUI. The samples were then rinsed with 5ml of saline for 1 min. Freshly mixed 10% sodium ascorbate solution was prepared by dissolving 10 gm of sodium a scorbate powder in 100 ml of distilled water. INTERNATIONAL JOURNAL OF SCIENTIFIC RESEARCH Endodontics International Journal of Scientific Research 23 Volume-9 | Issue-5 | May-2020 | PRINT ISSN No. 2277 - 8179 | DOI : 10.36106/ijsr ABSTRACT Aim- To evaluate the effect of antioxidant on pull-out bond strength of resin cement to dentin. Material and Methods- Post spaces were prepared in endodontically treated roots and were divided into four groups: Group A: Saline+ PUI, Group B: 17% EDTA+ PUI+ Saline, Group C: 5% NaOCl+ PUI+ 17% EDTA+ PUI+ Saline, Group D: 5% NaOCl+ PUI+ 17% EDTA+ PUI+ Saline+ 10% Sodium ascorbate+ Saline. Silanized fiber posts were bonded using RelyX U200 Automix. Thereafter, each specimen was embedded into self-cure acrylic resin using teflon ring moulds (2''X5/6''). The pull out bond strength for each sample was evaluated using Universal testing machine (at a cross head speed of 1.0 mm/min) and the force at which the sample debonded was recorded in mega pascal (MPa).The values thus obtained were tabulated and put to statistical analysis using One-Way ANOVA F and Independent “t”- test. Results- Highest pull-out bond strength was seen in Group A followed by Group D. Conclusion- Use of sodium ascorbate resulted in reversal of compromised bond strength caused by NaOCl. KEYWORDS Antioxidant, Pull-Out Bond Strength, Self-adhesive Resin Luting Cement.