Crestal Bone Response to Narrow vs. Regular Tie-Base in Subcrestal Implants
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Intervention Name (Arm 1): Narrow tie-base abutment Intervention Name (Arm 2): Regular tie-base abutment.
- Who it may be relevant to
- Registry conditions: Bone Loss. Basic parameters: 20 years — 70 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Center list to be confirmed — check the primary protocol.
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Evaluation of Crestal Bone Changes at Subcrestal Bone-level Implants With Narrow or Regular Tie-base: A Randomized Controlled Trial
Overview
This 24-month randomized clinical trial evaluates peri-implant marginal bone changes at subcrestal implants restored with narrow versus regular tie-base abutments. The study investigates whether narrow or regular tie-base abutments influence peri-implant crestal bone remodeling over 24 months. This trial assesses the effect of abutment diameter (narrow vs. regular tie-base) on marginal bone stability at subcrestal implants after 24 months. We aimed to determine if abutment diameter impacts peri-implant marginal bone levels by comparing narrow and regular tie-base abutments in a 24-month RCT.
Detailed description
INTRODUCTION The preservation of supracrestal peri- implant soft tissues plays a crucial role in maintaining bone tissue stability.(1) In recent decades, it has been suggested that peri- implant marginal bone loss is influenced by several factors, including the surface characteristics of the implant neck, the implant- abutment, abutment height, platform switching, and abutment dis/reconnection.(2) Limiting these disconnections has been shown to improve the maintenance of the peri- implant marginal bone level.
On the other hand, it has been observed that transmucosal abutments with convex designs can influence bone remodeling, even with platform switching, when compared to straight or concave abutments.(3,4) The hypothesis was that distancing the abutment- prosthesis interface from the implant shoulder and using narrower transmucosal abutments with platform switching could favor the maintenance of the peri- implant marginal bone level by reducing bone remodeling and the apical migration of the "biological width".
Although there is evidence regarding the influence of platform switching or abutment height on the maintenance of the peri- implant marginal bone level, the evidence on the effect of abutment diameter is limited.(5,6) Therefore, the aim of this 24- month randomized clinical trial is to evaluate changes in the peri- implant marginal bone level at implants restored narrow or regular tie-base after 24 months.
Interventions
- Device Intervention Name (Arm 1): Narrow tie-base abutment Intervention Name (Arm 2): Regular tie-base abutment
Arm 1 - Narrow tie-base abutment Intervention Name: Narrow tie-base abutment Intervention Type: Device Intervention Description: Participants received a subcrestal bone-level dental implant restored with a narrow-diameter tie-base abutment. Arm 2 - Regular tie-base abutment Intervention Name: Regular tie-base abutment Intervention Type: Device Intervention Description: Participants received a subcrestal bone-level dental implant restored with a regular-diameter tie-base abutment.
Primary outcome measures
- Crestal bone level changes around subcrestal implants [Time frame: 24 months after loading]
Eligibility criteria
\*\*Inclusion Criteria
Adults ≥18 years old.
Single missing tooth in a posterior quadrant, bordered by adjacent natural teeth.
Adequate bone volume to place implants 8.5-10 mm in length and 4 mm in diameter without the need for bone or soft tissue grafting.
Presence of a natural tooth or an implant-supported fixed restoration as an antagonist.
Good oral hygiene with a plaque index <25%.
Willing and able to comply with study procedures and follow-up schedule.
Provided written informed consent.
\*\*Exclusion Criteria
Systemic conditions or medications affecting bone metabolism (e.g., bisphosphonates, corticosteroids).
Untreated periodontitis, persistent oral infections, or poor oral hygiene.
Metabolic bone diseases (e.g., osteoporosis, renal insufficiency, immunodeficiency, leukocyte dysfunction).
History of head and neck radiotherapy.
Physical or mental disability preventing adequate oral hygiene or compliance.
Heavy smoking (>10 cigarettes/day).
Alcoholism or drug abuse.
Pregnancy or breastfeeding.
Bruxism or oral mucosal diseases.
Need for bone regeneration procedures before implant placement.
Inability or unwillingness to attend follow-up visits.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Quadruple blind
- Primary purpose
- Treatment
Study locations
Center list to be confirmed — check the primary protocol.
Identifiers
NCT: NCT07196228 · ADMNF-00425