フッ化ジアンミン銀塗布と光重合による天然象牙質う蝕病巣の改善効果：in vitro試験

Enhanced effectiveness of silver diamine fluoride application with light curing on natural dentin carious lesions: an in vitro study.

抄録

本研究の目的は，フッ化ジアミン銀（SDF）を10日間および60日間塗布した象牙質う蝕病巣の平均鉱物密度差（mMDD）と表面形態を比較すること，およびSDF処理歯に20日間の光照射（LC）を追加した場合の効果を検討することである．天然象牙質う蝕病変を有する乳臼歯40ブロックをImage-Pro Plusソフトウェアを用いてベースライン病変深さとミネラル密度を測定した。38%SDFを10秒（10SDF）、60秒（60SDF）、10秒+LC（10SDF+LC）、60秒+LC（60SDF+LC）の4群に無作為に分け、さらにpHサイクルのみの結果を評価するためにコントロール群を追加した。その後、全群で7日間のpHサイクルを行った。象牙質う蝕病巣のmMDDはデジタルサブトラクションX線分析により決定した。表面形態と元素組成は走査型電子顕微鏡とエネルギー分散型X線分光法で評価した。象牙質病変のmMDDは、二元配置ANOVA、一般化線形モデル分析を用いて解析した。光照射はmMDDに影響を及ぼす唯一の因子であった（p=0.007）。10SDF+LC群および60SDF+LC群のmMDDは、光照射を行わない群と比較して有意に高かった（それぞれp=0.041および0.041）。60SDF+LC群は10SDF群より有意に高いmMDDを示したが（p=0.010）、10SDF+LC群のそれは60SDF群と同程度であった（p=1.00）。走査型電子顕微鏡で観察したところ、10SDF+LC群と60SDF+LC群では、それぞれ10SDF群と60SDF群に比べ、銀と塩化物と思われる緻密なミネラル含有層が観察された。結論として、光重合による塗布時間の短縮は、従来法と同様にSDFの再石灰化を促進した。

This study aimed to compare the mean mineral density difference (mMDD) and surface morphology of 10- and 60-s silver diamine fluoride (SDF)-applied dentin carious lesions and to study the effect of an additional 20-s light curing (LC) on SDF-treated teeth. Forty primary molar blocks with natural dentin carious lesions were measured for baseline lesion depth and mineral density using Image-Pro Plus software. The samples were randomly distributed into 4 groups; 38% SDF applied for 1) 10-s (10SDF), 2) 60-s (60SDF), 3) 10-s + LC (10SDF + LC), 4) 60-s + LC (60SDF + LC) and an additional control group to assess the outcome of pH-cycling only. Then all the groups underwent a 7-d bacterial pH-cycling. The dentin carious lesions' mMDD was determined by digital subtraction radiographic analysis. The surface morphology and elemental profile were assessed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The mMDD of the dentin lesions was analyzed using two-way ANOVA, generalized linear models analysis. Light curing was the only factor that affected the mMDD (p = 0.007). The mMDD in the 10SDF + LC and 60SDF + LC groups were significantly higher than those without light curing (p = 0.041 and 0.041, respectively). The 60SDF + LC group demonstrated a significantly higher mMDD than the 10SDF group (p = 0.010), while that in the 10SDF + LC group was similar to the 60SDF group (p = 1.00). Scanning electron microscopy revealed denser mineral content layers, which were likely silver and chloride, in the 10SDF + LC and 60SDF + LC groups than in the 10SDF and 60SDF groups, respectively. In conclusion, shortened application time with light curing enhanced SDF remineralization similarly to the conventional method.