title: Effects of autoclaving on dimensional qualities and physical properties (flexural rigidity and brittleness) of newly developed root canal filling point made of polypropylene (FLEX POINT NEO).
abstract: In this study, we investigated the effects of 10 cycles of conventional autoclaving (121 degrees C, 20 min) on the dimensional integrity and physical properties (flexural rigidity and brittleness) of a newly developed root canal filling point made of polypropylene (FLEX POINT NEO). We measured the diameters of autoclave-sterilized and non-treated polypropylene points (020 through 070) and calculated the incidence of deviation from ISO specifications (6877.4.4.1, 1995). In order to ascertain physical properties, we tested autoclave-sterilized and non-treated polypropylene points (030, 050 and 070) for flexural rigidity. This was done by evaluating deflection value when a load was placed at the free tip-end of the point and brittleness in accordance with ISO specifications (6877.6.5.2). Ten cycles of autoclaving showed no significant effect on the diameters of the polypropylene points. All the polypropylene points in both the non-treated and the autoclave-sterilized groups met ISO specifications in terms of dimensional integrity of diameter. In the autoclave-sterilized group, 030 and 050 polypropylene points showed a slight decrease in flexural rigidity (3.4% in 030, 10.0% in 050). In terms of brittleness, none of polypropylene points showed any sign of fracture.
authors.affiliation: Fukushima Prefectural General Hygiene Institute, 61-Watari, Fukushima 960-8141, Japan. ohne@tb3.so-net.ne.jp
authors.forename: Mitsuasa
authors.initials: M
authors.lastname: Ohne
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Yamazaki
mesh_terms: D006358:Hot Temperature / Q000009:adverse effects*; D008422:Materials Testing; D018583:Pliability; D011126:Polypropylenes / Q000737:chemistry; D018915:Root Canal Preparation / Q000295:instrumentation*; D013242:Sterilization / Q000295:instrumentation
chemical_list: D011126:Polypropylenes