Table 2.
A summary of cell viability (cytotoxicity) at each time point (7 or 14 days) or solution concentrations (5%, 10%, and 20% vol/vol) of different clear aligner materials.
| Brand | Category | Composition | Cell viability (%) | Days or final solution concentration (% v/v) | Cytotoxicity |
|---|---|---|---|---|---|
| Duran [104] (Scheu-Dental GmbH, Iserlohn, Germany) |
Thermoformed | Polyethylen terephthalate glycol (PETG) |
84.6 ± 4.02 | 14 days | Slight |
| Biolon (Dreve Dentamid GmbH, Unna, Germany) |
Thermoformed | Polyethylene terephthalate glycol (PETG) |
64.6 ± 3.31 | 14 days | Slight |
| Zendura (Bay Materials LLC, Fremont, CA, USA) |
Thermoformed | Polyurethane resin (PU) |
74.4 ± 2.34 | 14 days | Slight |
| SmartTrack™ (Align Tech, San Jose, CA, USA) |
Thermoformed | Multilayer aromatic thermoplastic polyurethane/copolyester | 78.8 ± 6.35 | 14 days | Slight |
| E-Guard [106] (EnvisionTEC, Rockhill, SC, USA) |
3D printed | Photopolymer | 75.06 ± 8.98 | 7 days | Slight |
| Dental LT (Formlabsinc) |
3D printed | Photopolymer | 77.74 ± 3.22 | 7 days | Slight |
| SmartTrack™ (Align Tech, San Jose, CA, USA) |
Thermoformed | Multilayer aromatic thermoplastic polyurethane/copolyester | 94.07 ± 3.00 | 7 days | No |
| TC85A [107] (Graphy, Seoul, South Korea) |
3D printed | Photopolymerizable polyurethane | 97.6 ± 14.6 98.3 ± 15.9 92.0 ± 13.0 |
5% 4 10% 8 20% h |
No No No |
| SmartTrack™ [108] (Align Tech, San Jose, CA, USA) |
Thermoformed | Polyurethane | 82.6 ± 13.6 60.3 ± 8.8 54.5 ± 23.1 |
5% 7 10% 2 20% h |
Slight Slight Moderate |
| Eon (Eon Holding, Amman, JO) |
Thermoformed | Polyurethane resin (PU) |
85.1 ± 18.3 54.8 ± 16.8 60.4 ± 20.7 |
5% 10% 20% |
Slight Moderate Slight |
| Suresmile (Dentsply-Sirona, Charlotte, NC, USA) |
Thermoformed | Polyurethane resin (PU) |
85.4 ± 16.4 70.7 ± 15.8 56.8 ± 11.3 |
5% 10% 20% |
Slight Slight Moderate |
| Clarity (3 M, St Paul, MN, USA) |
Thermoformed | Polyurethane resin (PU) |
89.3 ± 15.0 72.9 ± 21.1 71.8 ± 15.4 |
5% 10% 20% |
Slight Slight Slight |
Cytotoxicity: No, cell viability more than 90%; Slight, cell viability 60%–90%; Moderate, cell viability 30%–59%; Severe, cell viability less than 30%.