Inadequate apical seal is the major cause of surgical endodontic failure. The root-end filling material used should prevent egress of potential contaminants into periapical tissue. The purpose of this study was to compare the sealing ability of four root-end filling materials: white mineral trioxide aggregate (MTA), gray MTA, white Portland cement (PC) and gray PC by dye leakage test. Ninety-six human single-rooted teeth were instrumented, and obturated with gutta-percha. After resecting the apex, an apical cavity was prepared. The teeth were randomly divided into four experimental groups (A: white MTA, B: gray MTA, C: white PC and D: gray PC; n = 20) and two control groups (positive and negative control groups; n = 8). Root-end cavities in the experimental groups were filled with the experimental materials. The teeth were exposed to Indian ink for 72 hours. The extent of dye penetration was measured with a stereomicroscope at 16× magnification. The negative controls showed no dye penetration and dye penetration was seen in the entire root-end cavity of positive controls. However, there was no statistically significant difference among the four experimental groups (P > 0.05). All retrograde filling materials tested in this study showed the same microleakage in vitro. Given the low cost and apparently similar sealing ability of PC, PC could be considered as a substitute for MTA as a root-end filling material. (J Oral Sci 53, 517-522, 2011)

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 本研究は，インドネシア東部のスラウェシ・マルク地方において，サゴヤシのオサゾウムシ（サゴムシ）の食用慣行がどのように繰り広げられているかを食用地の分布と様式に注目して検討した．調査対象地域では，サゴムシの幼虫および成虫が食べられるが，幼虫の方がより広範囲に食べられており，一般的である．サゴムシは，サゴヤシのデンプン利用と結びついて得られるという，生業に付随する採集資源である．複雑な採集技法は確立されておらず，とくに幼虫は容易に確保でき，手近に利用できる資源となっている．しかし，大量に採集が指向されるのでもなく，市場流通もせず，自給的である．一方，味に対する肯定的で高い評価，味を活かそうとする料理および利用形態（加熱・加工プロセス）から，サゴムシは嗜好品的に食物レパートリーを増す役割を担う資源であり，この地の食用昆虫の基層となっている．

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こぼれたわずかな粉餌からジンサンシバンムシが発生する可能性を調べるため，粉餌の厚さとジンサンシバンムシの生育との関係を実験的に調べた．

成虫発生可能な粉餌の厚みの限界は0.6～0.7mmであった．1.4mmまでの厚さの粉餌からは小型幼虫が発生した．粉餌2.5mm以上の厚さから発生したF₁成虫はすべて正常サイズだった．

サンプルビンを用いた試験において，餌の重量1gで厚さ7.0mmの区では多数のF₁，F₂の生育が認められたのに対し，同じ餌重量 (1g) 区のシャーレでは餌の厚さがわずかに0.625mmと薄く，シバンムシの生育はみられなかった．このことはわずかな食品のこぼれからでも本種の生育と発生が可能であり，こぼれた粉餌の厚みが重要であることを示している．

室温25℃，照明12L-12Dの条件でF₂幼虫はすべて休眠状態に入った．休眠幼虫は5℃，2ヶ月冷蔵後，5～6月の室温に戻すと1ヶ月半後羽化した．冷蔵しなくても，休眠幼虫の多くは6～10ヶ月 (25℃) で羽化した．これは本種の休眠幼虫が低温に耐え，低温条件下で休眠発育が進むこと，また，連続した高温条件下でも結局踊化し羽化することを示している．

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The purpose of this study was to evaluate, in vitro, the antimicrobial effect of iRoot BP, iRoot BP Plus, and mineral trioxide aggregate (MTA) against Entercoccus faecalis and Candida albicans by using direct contact test. The materials were tested immediately after application to the microtiter wells and after setting for 1-day and for 7-days. Ten microliters of microbial suspension was added to each well for direct contact with each material for 1 h at 37°C and 100% humidity. Then fresh media was added and, survival of bacteria and fungi was determined by using 10-fold serial dilution and inoculated onto agar plates. In fresh and 1-day samples all of tested materials showed statistically significant antimicrobial effects compared to control groups (p<0.05). In 7-day samples, there were no significantly differences compared to control groups. MTA, iRoot BP and iRoot BP Plus had similar antimicrobial efficacy against E. faecalis and C. albicans.

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The aim of this study was to evaluate the sealing ability of mineral trioxide aggregate (MTA Bio) combined with different mixing agents (distilled water, chlorhexidine, doxycycline), used as an apical root-end filling material. Forty-two extracted human teeth were divided into three groups (n = 12); six teeth were used as controls. Root-ends were resected at 90 degrees, 3 mm from the apex. Root-end cavities were prepared using ultrasonic tips and filled with MTA Bio plus distilled water, 2% chlorhexidine solution, or 10% doxycycline solution. Apical sealing was assessed by microleakage of 50% silver nitrate solution. Roots were longitudinally sectioned in a buccolingual plane and analyzed using an operating microscope (20× magnification). Depth of dye leakage into the dentinal walls was measured in millimeters. Results were analyzed using ANOVA and Tukey's test (P = 0.05). MTA Bio plus distilled water showed significantly higher mean leakage results (1.06 mm) when compared with MTA Bio plus doxycycline (0.61 mm), and higher, although not significant, results when compared with MTA Bio plus chlorhexidine (0.79 mm). In conclusion, replacing distilled water with two biologically active mixing agents (doxycycline and chlorhexidine) did not alter the sealing properties of MTABio. The antimicrobial properties of these combinations should be further investigated. (J Oral Sci 54, 233-239, 2012)

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