Evaluation of Physical Changes in Single-Layer and Multi-Layer Clear Aligners After Thermoforming and Intraoral Wear
试验速览
- 阶段
- 不适用
- 状态
- 进行中（未招募）
- 入组人数
- 20
- 试验地点
- 1
- 主要终点
- surface roughness of clear aligner
研究概览
简要总结
aim of the study: to evaluate and compare the surface roughness (Ra, Rq, Rz), Vickers microhardness (VHN), and thickness of single-layer and multi-layer clear aligner sheets.
material and methods: the study will be conducted on clear aligners fabricated from two commercial thermoplastic materials: single-layer (0.76 mm, ) and multi-layer (0.76 mm, ). Each material will be evaluated at three stages: before thermoforming, after thermoforming on 3D-printed casts, and after 2 weeks of intraoral wear.
Specimen Preparation For each group, specimens will be prepared at three stages: before thermoforming (T0), after thermoforming (T1), and after intraoral wear (T2). At T0, square-shaped specimens (approximately 5 × 5 mm) will be cut directly from the unused raw sheets. At T1 and T2, specimens of the same dimensions will be obtained from the mid-labial surface of the central incisor region of the thermoformed aligners, both immediately after thermoforming and after two weeks of intraoral wear. The full thickness of the material will be preserved in all specimens to ensure consistency across groups.
Outcomes:
Primary Outcome:
Surface Roughness (Ra):
Measured at three stages:
T0: Raw, unused sheet specimens (baseline) T1: After thermoforming on dental casts T2: After 2 weeks of intraoral use
Secondary Outcomes:
Hardness:
Measured at T0, T1, and T2. Tested using Vickers hardness method (ISO 6507 compliant).
详细描述
aim of the study: To evaluate and compare the surface roughness (Ra, Rq, Rz), Vickers microhardness (VHN), and thickness of single-layer and multi-layer clear aligner sheets at three stages: before thermoforming, after thermoforming, and following intraoral wear.
material and methods: This in vivo study will be conducted on clear aligners fabricated from two commercial thermoplastic materials: single-layer (0.76 mm, ) and multi-layer (0.76 mm, ). Each material will be evaluated at three stages: before thermoforming (raw sheet), after thermoforming on 3D-printed casts, and after 2 weeks of intraoral wear. At each stage, specimens will be retrieved and tested for changes in mechanical properties, specifically surface roughness and hardness.
Study Design Type: A prospective, randomized, controlled, two-arm parallel clinical study
Design Details: participants will be randomly assigned to one of two groups:
Group A:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 16 Years 至 24 Years（Child, Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Class I malocclusion with mild-moderate crowding (≤5 mm per arch).
- •Full permanent dentition (excluding third molars).
- •No restorations, caries, or attachments planned on the labial surface of upper/lower central incisors.
排除标准
- •Systemic disease affecting saliva.
- •Parafunctional habits (bruxism, nail-biting).
- •Pregnancy.
- •Previous orthodontic treatment within 1 year.
研究组 & 干预措施
Multi-layer clear aligners
clear aligners fabricated from thermoplastic materials: multi-layer (0.76 mm). the material will be evaluated at three stages: before thermoforming (raw sheet), after thermoforming on 3D-printed casts, and after 2 weeks of intraoral wear. At each stage, specimens will be retrieved and tested for changes in mechanical properties, specifically surface roughness and hardness.
Baseline control: Unused aligner sheets of both types to serve as reference for measurements.
干预措施: clear aligner (Device)
Single-layer clear aligners
clear aligners fabricated from thermoplastic materials: single-layer (0.76 mm) . the material will be evaluated at three stages: before thermoforming (raw sheet), after thermoforming on 3D-printed casts, and after 2 weeks of intraoral wear. At each stage, specimens will be retrieved and tested for changes in mechanical properties, specifically surface roughness and hardness.
Baseline control: Unused aligner sheets of both types to serve as reference for measurements.
干预措施: clear aligner (Device)
结局指标
主要结局
surface roughness of clear aligner
时间窗: 2 weeks
evaluate and compare the surface roughness of single-layer and multi-layer clear aligner sheets at three stages: before thermoforming, after thermoforming, and following intraoral wear. Quantitative evaluation of the arithmetic mean surface roughness (Ra) using profilometer
次要结局
- microhardness of clear aligner(2 weeks)
- thickness change of clear aligner(2 weeks)