The Effect of Different Organic Solvents on Retreatment Filling Removal and Bond Strength during Endodontic Retreatment /

Abstract

Endodontic treatment occasionally fails due to persistent microbial invasion and extra-radicular infection. Furthermore, the occurrence of different endodontic mishaps during access cavity, root canal instrumentation and obturation act as supplementary factors that help in development of secondary apical periodontitis. The aim of endodontic treatment is to fully clean and disinfects the root canal system. Successful retreatment depends on the ability to remove the root filling material to ensure thorough cleaning and shaping with minimizing the bacterial load and infected root canal filling material. Retreatment is done either mechanically, chemically, and thermally or by combining of more than one method to ensure optimum removal of root canal filling material. Mechanically by using manual or rotary files to gain access to full working length, chemically by using solvents and thermally using……………... During root canal retreatment, the clinician might try to remove different types of root canal sealers in different retreatment cases. Some types are hard to be removed than others as resin sealers. One of the most commonly used resin sealers is AH Plus epoxy resin sealer which has acceptable physicochemical properties. With such hard setting sealer, it is favorable to use both of solvents and any mechanical mean as rotary instruments which are especially designed for retreatment. Chemical dissolving of root canal filling material is done using different solvents. Chloroform is one of the most widely used solvents because of its efficiency, however its known to be toxic. Oily solvents, which are alternatives to chloroform to avoid its toxicity, have been developed. These oil-based solvents like orange oil and eucalyptol. Scarce data are available about the effectiveness of orange oil in removing root canal filling material. The use of chemical solvents leaves remnants on the dentinal walls which could affect the final bond of endodontic sealers during endodontic retreatment. Also the use of oily solvents might leave residues which can affect the bond strength of resin sealer. In this study organic solvents (Oily solvents; orange oil and eucalyptus oil) were evaluated for their effectiveness in removal of root canal filling material in comparison to chloroform. Furthermore, studying their effect on the final Bond strength of AH Plus resin sealer after endodontic retreatment is considered to be of a great value.