Evaluation of Effect of Different Cavity Disinfectants on Shear Bond Strength of Composite Resin to Dentin using Two-Step Self-Etch and One-Step Self-Etch Bonding Systems: A Comparative in vitro Study

Abstract

Aim and objectives: To evaluate the effect of 2% chlorhexidine, 2% sodium hypochlorite, 3% hydrogen peroxide on shear bond strength of composite resin to dentin using two-step and onestep self-etch bonding systems and to study the mode of failure of specimens under stereomicroscope. Materials and methods: Eighty extracted sound human posterior teeth were used. The occlusal surfaces were ground to expose the dentin and were then randomly divided into 4 main groups. In group I, no cavity disinfectant was used and served as control. In groups II, III, IV, 2% chlorhexidine, 2% sodium hypochlorite and 3% hydrogen peroxide were used as cavity disinfectants respectively. Each group was then divided into two subgroups of 10 teeth each according to the bonding agent used, two-step self-etch (Adper SE Plus) and one-step self-etch (Adper Easy One) respectively. A transparent cylindrical plastic tube was loaded with microhybrid composite and placed over the dentin and light cured for 40 seconds. The specimens were subjected to shear stress in the universal testing machine. Results: Pretreatment with 2% chlorhexidine, 2% sodium hypochlorite and 3% hydrogen peroxide, had a negative effect on the shear bond strength of self-etching bonding systems. Conclusion: The highest bond strength was found in 2% chlorhexidine group followed by 2% sodium hypochlorite group and the lowest bond strength was found in 3% hydrogen peroxide group. Clinical significance: All three cavity disinfectants used in this study reduced the shear bond strength and hence should be used with caution.

Effect of Different Cavity Disinfectants on Marginal Sealing Ability of a Seventh-generation Dentin Bonding Agent: An In Vitro Study

“…Group II (2.5% sodium hypochlorite) showed statistically significant differences in microleakage scores when compared with the negative control group. This finding is in accordance with other studies conducted by Frankenberger et al, 18 Bansal and Tewari, 31 Ercan et al, 11 Mirzaei et al, 32 Pattanaik and Chandak, 33 and Reddy et al 15 Study by Lai et al suggested greater microleakage and poor adaptation of resin to dentin surface with different adhesive system after sodium hypochlorite treatment could be associated with the oxidizing effect of sodium hypochlorite and its reaction by-products, thus causing interruption in the interfacial polymerization of adhesives. The premature chain termination and incomplete polymerization of adhesives could be related to residual reactive free radicals in dentin with sodium hypochlorite treatment reacting with propagating free vinyl radicals generated during light activation of the adhesive resin, leading to increased microleakage.…”

“…4 Growth of microorganisms under a restoration results in tooth hypersensitivity, weakening of bond strength, development of secondary caries, pulpal inflammation, and necrosis of the pulp. 15 It is believed that gross disinfection of the cavity preparation before inserting the restorative material is the best that can be achieved to reduce the potential risk of sensitivity and residual caries. 16 In the last decades, many chemicals have been tested as cavity disinfectants, including chlorhexidine gluconate, benzalkonium chloride, iodine potassium iodide/copper sulfate, fluoride, sodium hypochlorite, etc.…”

Effect of a novel quaternary ammonium silane based cavity cleanser FiteBac 2% K21 QAS in comparison with other cavity disinfectants on the bond strength of resin-modified glass ionomer cement

“…[ 22 ] and Reddy et al . [ 23 ] where resin-bond strength declined when composite resins with different bonding systems were used. This is because the collagen matrix and dentinal tubules may have retained some amount of H 2 O 2 that eventually decomposed into oxygen and water.…”