The effect of sodium hypochlorite irrigant concentration on tooth surface strain.
The effect of root-canal irrigation with different concentrations of sodium hypochlorite (3%, 5.1%, 7.3% NaOCI) on the mechanical properties of teeth was investigated in vitro. Root canals of 13 extracted, human premolars, denuded of enamel, were prepared with nickel-titanium rotary instruments (Quantec) to a standard size by using saline irrigation. An electrical strain gauge was bonded to the cervical aspect of each tooth. The 10 experimental teeth were subjected to 5 successive, 30-minute periods of irrigation. The irrigants were used in the following order: (a) saline; (b) 3.0% NaOCI; (c) 5.1% NaOCI; (d) 7.3% NaOCI; (e) saline. Three control teeth were irrigated with saline only for all five periods. After each irrigation, the teeth were cyclically loaded to 110N while the surface strain was measured. Changes in strain of the test teeth after each irrigation regimen followed broadly similar patterns that were different from the control teeth. There was no difference, however, in the strain recorded after irrigation by the different irrigants within the experimental group.
Department of Conservative Dentistry, Eastman Dental Institute for Oral Health Care Sciences, University College London, United Kingdom.
Michael
M
Goldsmith
Kishor
K
Gulabivala
Jonathan C
JC
Knowles
D000704:Analysis of Variance; D001641:Bicuspid / Q000187:drug effects* / Q000502:physiology; D003722:Dental Alloys; D003799:Dental Stress Analysis / Q000295:instrumentation; D006801:Humans; D009532:Nickel; D012388:Root Canal Irrigants / Q000008:administration & dosage / Q000494:pharmacology*; D018915:Root Canal Preparation / Q000295:instrumentation; D012965:Sodium Chloride; D012973:Sodium Hypochlorite / Q000008:administration & dosage / Q000494:pharmacology*; D013223:Statistics as Topic; D013314:Stress, Mechanical; D013997:Time Factors; D014025:Titanium; D014159:Transducers
D003722:Dental Alloys; D012388:Root Canal Irrigants; C040654:titanium nickelide; D012965:Sodium Chloride; D009532:Nickel; D014025:Titanium; D012973:Sodium Hypochlorite