3Dプリント義歯床における重合方法の違いによる補修材の剪断接着強さ

Shear Bond Strength of Repair Materials by Different Polymerization Methods on 3D-Printed Denture Bases.

抄録

目的:

3Dプリント義歯床（DLP）に対する重合方法の違いによる義歯補修材料の剪断接着強さ（SBS）を、自己重合ポリメチルメタクリレート義歯床（PMMA）と比較して検討すること。

PURPOSE: To investigate shear bond strengths (SBSs) of denture repair materials using different polymerization methods to a 3D-printed denture base (DLP) compared to an autopolymerized polymethyl methacrylate denture base (PMMA).

材料と方法:

DLPおよびPMMAディスクを作製し、#400炭化ケイ素研磨紙を用いて粗面化し、それぞれの補修材料のプライマー/接着剤で処理した。自己重合型義歯補修材（PER）または軽重合型義歯リライニング材（MRB）をディスク上に重合させた。試験片はすべて37℃の蒸留水中に24時間保存した。試験片の半数をサーモサイクル（TC；5,000サイクル、5～55℃）にかけた。SBS試験を行い（各群n = 20）、破壊パターンを分析した。SBSデータはノンパラメトリックのKruskal- Wallis検定および最尤推定によるWeibull分布を用いて分析した。

MATERIALS AND METHODS: DLP and PMMA disks were fabricated, roughened using #400 silicon carbide abrasive paper, and treated with the primer/bonding of the respective repair material. An autopolymerized denture repair material (PER) or a light-polymerized denture relining material (MRB) was polymerized on the disks. All specimens were stored in distilled water at 37°C for 24 hours. Half of the specimens underwent thermocycling (TC; 5,000 cycles, 5 to 55°C). SBS testing was conducted (n = 20 per group), and the fracture pattern was analyzed. The SBS data were analyzed using nonparametric Kruskal- Wallis tests and Weibull distributions with the maximum likelihood estimation.

結果:

MRBはPERよりもSBSおよびワイブル特性強度が有意に高かった（P < 0.001）．ワイブル弾性率については，最も高い値を示したPMMA-MRB試験片を除き，各試験片間に統計的な差は認められなかった（P < 0.001）．熱老化はこれらの値を低下させる傾向があったが，非TC群とTC群の間に有意差は認められなかった．接着破壊は，義歯床内の凝集破壊に移行したDLP-MRB試験片を除き，すべての試験片で支配的に観察された．

RESULTS: MRB specimens showed significantly higher SBS and Weibull characteristic strength values than PER specimens (P < .001), irrespective of the denture base material. No statistical differences were observed in Weibull modulus among the specimens, except PMMA-MRB specimens, which showed the highest values (P < .001). Thermal aging tended to decrease these values; however, no significant differences were observed between the non-TC and TC groups. Adhesive failure was dominantly observed in the specimens, except DLP-MRB specimens, which shifted to cohesive failures within the denture base.

結論:

DLP試験片の修復性はPMMA試験片と同等であった．したがって，DLP義歯床の義歯修復は，従来のPMMA義歯床と同様に行うことができる．

CONCLUSIONS: The repairability of the DLP specimens was comparable to those of the PMMA specimens. Thus, denture repair of the DLP denture base could be treated in the same manner as a conventional PMMA denture base.