アルジネート印象材と保存期間が石材模型の表面細部の再現性と寸法精度に及ぼす影響

Influence of alginate impression materials and storage time on surface detail reproduction and dimensional accuracy of stone models.

• Ricardo D Guiraldo
• Ana F F Moreti
• Julia Martinelli
• Sandrine B Berger
• Luciana L Meneghel
• Rodrigo V Caixeta
• Mário A C Sinhoreti

抄録

本研究では，異なるアルジネート印象材（Cavex ColorChange，Hydrogum 5，Jeltrate Plus）を用い，異なる保存期間（1，3，5日）で作製した鋳型から得られた石材模型の表面細部の再現性と寸法精度を，保存期間を設けずに直ちに充填した鋳型から得られた模型と比較した。鋳型は、50μmのラインを含むマトリックス（ISO 1563規格）の上に、パンチングメタルのトレイを用いて加圧して準備した。粘り気がなくなってから2分後に型を外し，すぐに充填するか，密閉したジャーに入れて相対湿度100％，37℃で1，3，5日間保存した。型には歯科用石膏（Durone IV）を充填した。表面細部の再現性と寸法精度は，ISO 1563規格に基づいて，長さ25mmの50μm幅の線上で光学顕微鏡を用いて評価した。寸法精度の結果（％）は分散分析の対象とした。50μm幅の線（ISO1563規格）は，保存期間によらず，すべてのアルジネート印象材で完全に再現された。また，異なるアルジネート印象材で構成された鋳型を用い，保存期間を変えて作製した石材模型の平均寸法精度値には，統計的に有意な差は認められなかった（p＝0.989）。結論として，充填前に型を5日間保管しても，本研究で検討したアルジネートの表面細部の再現性や寸法精度に変化はなかった．

This study compared the surface detail reproduction and dimensional accuracy of stone models obtained from molds prepared using different alginate impression materials (Cavex ColorChange, Hydrogum 5, or Jeltrate Plus) and with different storage times (1, 3, and 5 days) to models from molds that were filled immediately with no storage time. The molds were prepared over a matrix containing 50-μm line, (ISO 1563 standard) under pressure with a perforated metal tray. The molds were removed 2 minutes after loss of sticky consistency and either filled immediately or stored in closed jars at 100% relative humidity and 37°C for 1, 3, or 5 days. The molds were filled with dental plaster (Durone IV). Surface detail reproduction and dimensional accuracy were evaluated using optical microscopy on the 50-μm wide line, which was 25 mm in length, according to ISO 1563 standard. The dimensional accuracy results (%) were subjected to analysis of variance. The 50-μm wide line (ISO 1563 standard) was completely reproduced by all alginate impression materials regardless of the storage time. There was no statistically significant difference in the mean dimensional accuracy values of stone models made from molds composed of different alginate impression materials and with different storage times (p = 0.989). In conclusion, storing the mold for five days prior to filling did not change the surface detail reproduction or dimensional accuracy of the alginates examined in this study.