Subcrestal Placement of PRAMA Implants With Convergent Neck Incorporating Ultrathin Threaded Microsurface: A Randomized Controlled Clinical Trial
试验速览
- 阶段
- 不适用
- 状态
- 进行中（未招募）
- 发起方
- 入组人数
- 30
- 试验地点
- 2
- 主要终点
- Change in Peri-Implant Bone Height Over Time
研究概览
简要总结
The goal of this clinical trial is to understand how different implant neck designs and placement depths affect the surrounding bone and peri-implant tissue (the tissue around a dental implant) in adults who need implants in the back areas of the mouth (molars and premolars). The main questions it aims to answer are:
Does placing implants deeper under the bone crest (subcrestally) help preserve more bone and peri-implant tissue over time? Do implants with longer, conical necks and micro-threaded surfaces result in more stable peri-implant tissue than implants with shorter necks? Researchers will compare three types of one-piece dental implants with different neck heights (short, standard, and long), placed at different depths in the jawbone, to determine which combination better maintains bone and peri-implant tissue levels.
Participants will:
Receive two dental implants in the posterior upper or lower jaw Be randomly assigned to one of three groups depending on implant neck design and placement depth Undergo implant surgery using a digital workflow, with healing over three months Be rehabilitated with custom zirconia bridges Return for regular clinical and imaging checkups over a period of at least 3 years This study aims to generate evidence that helps clinicians choose implant designs and techniques that promote long-term peri-implant tissue health.
详细描述
This randomized controlled clinical trial investigates the impact of different transmucosal neck configurations and vertical placement levels of one-piece dental implants on peri-implant hard and soft tissue stability over time. The trial specifically focuses on the PRAMA implant system (Sweden & Martina, Italy), which incorporates a ZirTi surface and a convergent neck design with an Ultrathin Threaded Microsurface (UTM). These implants are designed to optimize tissue integration and minimize marginal bone loss.
The study explores how subcrestal versus crestal placement of the rough-to-smooth transition, combined with variable neck lengths, influences peri-implant tissue outcomes under functional loading in posterior edentulous sites. Three types of PRAMA implants will be compared:
Short neck (1.8 mm total length with hyperbolic convergent shape)
Standard neck (0.8 mm cylindrical plus 2.0 mm convergent portion)
Long neck (0.8 mm cylindrical plus 3.0 mm convergent portion)
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
- Single (Outcomes Assessor)
盲法说明
Allocation concealment is ensured via sealed opaque envelopes opened at the time of surgery. The surgeon is blinded to group assignment until after flap elevation, and the prosthetic team is unaware of crown design assignment until delivery. The outcomes assessor responsible for radiographic, CBCT, and 3D volumetric evaluations remains blinded to treatment allocation throughout the study.
入排标准
- 年龄范围
- 21 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Adults aged 21 years or older.
- •Presence of an edentulous area in the posterior maxilla or mandible (premolar or molar region) that allows the placement of two dental implants.
- •Alveolar bone height sufficient to permit implant insertion with a minimum depth of 6 mm, and total implant length of at least 10 mm.
- •Indication for implant-supported prosthetic restoration (2- or 3-unit fixed dental bridge).
- •Good general health with no contraindications for oral surgical procedures.
- •Not pregnant at the time of screening.
- •Willingness and ability to sign written informed consent and comply with study procedures.
排除标准
- •Presence of uncontrolled systemic disease (e.g., diabetes, cardiovascular disorders, immunosuppression).
- •History of chemotherapy or radiotherapy to the head or neck region.
- •Heavy smokers (defined as >10 cigarettes per day)
- •Previous bone regeneration or grafting procedures at the target implant site.
- •Use of medications known to interfere with bone metabolism (e.g., bisphosphonates, corticosteroids).
- •Poor oral hygiene or active periodontal disease that may compromise implant success.
- •Known allergy or hypersensitivity to implant materials used in the study-
结局指标
主要结局
Change in Peri-Implant Bone Height Over Time
时间窗: Baseline (prosthesis delivery), 6 months, and annually up to 3 years post-loading
Vertical changes in marginal bone level from the implant-abutment junction to the first bone-to-implant contact (BIC) at mesial and distal aspects, measured on standardized periapical radiographs, CBCT, and digital scans. Unit of Measure: Millimeters (mm)
次要结局
- Volumetric Change in Peri-Implant Tissues(Baseline (prosthesis delivery), 6 months, and annually up to 3 years post-loading)
- Tissue Volume Difference by Crown Emergence Profile(6 months and annually up to 3 years post-loading)
- Probing Pocket Depth at Implant Sites(6 months and annually up to 3 years post-loading)
- Plaque Index at Implant Sites (0-3 scale)(6 months and annually up to 3 years)
- Bleeding on Probing at Implant Sites (percentage of sites)(6 months and annually up to 3 years)