Niobium pentoxide as a new filler for methacrylate‐based root canal sealers. (11th August 2012)

• Record Type: Journal Article
• Authors: Leitune, V. C. B.; Takimi, A.; Collares, F. M.; Santos, P. D.; Provenzi, C.; Bergmann, C. P.; Samuel, S. M. W.
• Is Part Of: International endontic journal. Volume 46:Number 3(2013:Mar.)
• Page Start: 205
• Page End: 210
• Publication Date: 2012-08-11
• Subjects: Endodontics -- Periodicals; 617.6342
• DOI: 10.1111/j.1365-2591.2012.02107.x
• Languages: English
• ISSNs: 0143-2885

Abstract

<abstract abstract-type="main" id="iej2107-abs-0001"> <title>Abstract</title> <sec id="iej2107-sec-0001" sec-type="section"> <title>Aim</title> <p>To evaluate the influence of several niobium pentoxide (<italic>Nb<sub>2</sub>O<sub>5</sub></italic>) concentrations on the radio‐opacity, flow, film thickness, microhardness and degree of conversion of an experimental root canal sealer.</p> </sec> <sec id="iej2107-sec-0002" sec-type="section"> <title>Methodology</title> <p>An experimental dual‐cured root canal sealer was produced with a methacrylate‐based comonomer blend. <italic>Nb<sub>2</sub>O<sub>5</sub></italic> was added at four different concentrations: 0, 80, 100 and 120 wt%. Radio‐opacity was evaluated according to ISO 6876 using a digital system (<italic>n</italic> = 5). Flow and film thickness were determined in accordance with ISO 6876 (<italic>n</italic> = 3). Microhardness was evaluated with 50 g for 15 s (<italic>n</italic> = 5). Degree of conversion was evaluated with FTIR immediately after photocuring and after 1, 7 and 14 days. The data were analysed using <sc>anova</sc> and Tukey's test. The degree of conversion over time was evaluated using RM‐<sc>anova</sc> (α = 0.05).</p> </sec> <sec id="iej2107-sec-0003" sec-type="section"> <title>Results</title> <p>The groups with 80 wt% and 100 wt% of filler showed no significant difference in radio‐opacity from that of equivalent 2 mmAl (<italic>P</italic> > 0.05). The addition of 120 wt% resulted in radio‐opacity values higher than 2 mmAl (<italic>P</italic> < 0.05). The flow was not significantly different amongst the different groups (<italic>P</italic> > 0.05). All groups had a film thickness of <50 μm (ISO 6876). All groups with <italic>Nb<sub>2</sub>O<sub>5</sub></italic> were associated with higher values of microhardness than the control group. The group with 0 wt% was associated with a higher degree of conversion at all times. All groups except those with 80 wt% had higher values for degree of conversion after 14 days than immediately after photocuring.</p> </sec> <sec id="iej2107-sec-0004" sec-type="section"> <title>Conclusion</title> <p>The addition of <italic>Nb<sub>2</sub>O<sub>5</sub></italic> increases radio‐opacity and microhardness; this material may be a promising filler for the production of a new endodontic sealer.</p> </sec> </abstract>