Comprehensive Dentistry Department, College of Dentistry, Texas A&M University, Dallas, TX.
Restorative Dentistry, School of Dentistry, University of Washington, Seattle, WA.
J Prosthodont. 2021 Oct;30(8):698-705. doi: 10.1111/jopr.13302. Epub 2020 Dec 24.
To measure the chemical composition, Knoop hardness, surface roughness, and composite bond strength of additive manufactured (AM) and conventional interim materials.
Disks were prepared using conventionally (CNV group) and additively manufactured (AM group) materials: CNV-1 (Protemp 4; 3M ESPE), CNV-2 (Anaxdent new outline dentin; Anaxdent), AM-1 (FreePrint temp; Detax), AM-2 (E-Dent 400 C&B MFH; Envisiontec), AM-3 (NextDent C&B MFH; 3D Systems), and AM-4 (Med620 VEROGlaze; Stratasys). Each group was subdivided into 3 subgroups (n = 20) for analyzing Knoop hardness (KHN), chemical composition, superficial roughness (Ra), and composite shear bond strength. The first subgroup was exposed to a microhardness test. Subsequently, EDAX analysis was selected to analyze the chemical composition. The second subgroup was selected to measure the superficial roughness (Ra) using a contact profilometer. The third subgroup was used to measured composite shear bond strength using a universal testing apparatus. A digital microscope was used to analyze the fracture mode. The Shapiro-Wilk test showed normally distributed data. One-way ANOVA and post hoc Sidak tests were selected (α = 0.05).
Major variances in chemical composition were observed among the specimens. Significant differences in Knoop hardness (p < 0.001) and surface roughness (p < 0.001) were detected. The AM-4 (13.45 ± 2.93 KHN), the CNV-2 (13.35 ± 5.84 KHN), the AM-2 (13.03 ± 3.29 KHN), and the AM-1 (12.55 ± 2.93 KHN) groups obtained the highest Knoop hardness values, followed by the AM-3 and the CNV-1 groups (p < 0.05). The AM-1 group (1.88 ± 1.11 Ra) obtained the highest surface roughness values among the groups, followed by the AM-3 group (0.90 ± 0.14 Ra) (p < 0.05). However, no significant differences in shear bond strength values were found between the groups ranging from 23.18 ± 8.88 MPa to 33.29 ± 9.17 MPa (p = 0.061). All the groups showed a cohesive mode of failure.
The AM interim materials tested had significant chemical composition variations compared to conventional materials. For the mechanical properties evaluated, the AM materials obtained appropriate mechanical properties for use as an interim dental restoration. However, further studies are required to evaluate more extensively its mechanical properties and verify their applicability in the oral cavity, clinical behavior, and biocompatibility.
测量增材制造（AM）和常规临时材料的化学成分、努普硬度、表面粗糙度和复合粘结强度。
使用常规（CNV 组）和增材制造（AM 组）材料制备圆盘：CNV-1（Protemp 4；3M ESPE）、CNV-2（Anaxdent new outline dentin；Anaxdent）、AM-1（FreePrint temp；Detax）、AM-2（E-Dent 400 C&B MFH；Envisiontec）、AM-3（NextDent C&B MFH；3D Systems）和 AM-4（Med620 VEROGlaze；Stratasys）。每组再分为 3 个亚组（n=20），分别分析努普硬度（KHN）、化学成分、表面粗糙度（Ra）和复合剪切粘结强度。第一亚组进行显微硬度测试。随后选择 EDAX 分析以分析化学成分。选择第二亚组使用接触式轮廓仪测量表面粗糙度（Ra）。使用万能试验机测量第三亚组的复合剪切粘结强度。使用数字显微镜分析断裂模式。Shapiro-Wilk 检验显示数据呈正态分布。选择单因素方差分析和事后 Sidak 检验（α=0.05）。
观察到各标本化学成分存在较大差异。努普硬度（p<0.001）和表面粗糙度（p<0.001）存在显著差异。AM-4（13.45±2.93 KHN）、CNV-2（13.35±5.84 KHN）、AM-2（13.03±3.29 KHN）和 AM-1（12.55±2.93 KHN）组获得的努普硬度值最高，其次是 AM-3 和 CNV-1 组（p<0.05）。AM-1 组（1.88±1.11 Ra）的表面粗糙度值最高，其次是 AM-3 组（0.90±0.14 Ra）（p<0.05）。然而，各组之间的剪切粘结强度值无显著差异，范围为 23.18±8.88 MPa 至 33.29±9.17 MPa（p=0.061）。所有组均表现为内聚性破坏模式。
与常规材料相比，测试的 AM 临时材料的化学成分存在显著差异。对于评估的机械性能，AM 材料获得了作为临时牙科修复体使用的适当机械性能。然而，需要进一步研究以更广泛地评估其机械性能，并验证其在口腔内的适用性、临床行为和生物相容性。
