The effect of surfactant on the dissolution of porcine pulpal tissue by sodium hypochlorite solutions.
BACKGROUND
A previous study of the relative dental pulp-dissolving abilities of Milton brand of sodium hypochlorite (NaOCl) and other surfactant-containing NaOCl solutions produced specifically for endodontic treatment showed a markedly better performance of the surfactant-containing product that was not explained by differences in active chlorine content. This study investigated whether the presence of surfactant in the NaOCl solutions was responsible for the difference in dissolution times seen in the previous study.


METHODS
Circular samples 2.5 mm in diameter were punched out of the pulps of mandibular incisor teeth from young pigs. The 4 NaOCl solutions tested were Hypochlor 1% and Hypochlor 4% forte, which contained surfactant, and 2 identical solutions without surfactant. Twenty pulp specimens were immersed in 20 individual 25-mL aliquots of each of the 4 NaOCl solutions and observed while stirring until dissolution was complete. The time to dissolution of each sample was determined by stopwatch. Dissolution times for each solution were averaged and compared statistically in R (version 2.12.0) by using multiple regression with nominal active chlorine content as a covariate.


RESULTS
No statistical difference was detected between the dissolution times for either of the Hypochlor solutions with and without surfactant.


CONCLUSIONS
The addition of surfactant alone does not appear to improve the abilities of NaOCl to dissolve dental pulp tissue.
School of Dentistry, University of Queensland, Brisbane, Queensland, Australia. rogercla@ozemail.com.au
Roger M
RM
Clarkson
Bruce
B
Kidd
Gareth E
GE
Evans
Alex J
AJ
Moule
D000818:Animals; D002713:Chlorine / Q000032:analysis; D003782:Dental Pulp / Q000187:drug effects*; D007101:Immersion; D008422:Materials Testing; D011897:Random Allocation; D012388:Root Canal Irrigants / Q000032:analysis / Q000494:pharmacology*; D012973:Sodium Hypochlorite / Q000032:analysis / Q000494:pharmacology*; D012995:Solubility; D013501:Surface-Active Agents / Q000494:pharmacology*; D013552:Swine; D013997:Time Factors
D012388:Root Canal Irrigants; D013501:Surface-Active Agents; D002713:Chlorine; D012973:Sodium Hypochlorite