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Crestal Bone Response to Narrow vs. Regular Tie-Base in Subcrestal Implants

Evaluation of Crestal Bone Changes at Subcrestal Bone-level Implants With Narrow or Regular Tie-base: A Randomized Controlled Trial

Status
Not yet recruiting
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07196228
Enrollment
40
Registered
2025-09-29
Start date
2025-09-30
Completion date
2028-12-01
Last updated
2025-09-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Bone Loss

Brief summary

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

DEVICEIntervention 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.

Sponsors

Mansoura University
CollaboratorOTHER
Menoufia University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
20 Years to 70 Years
Healthy volunteers
Yes

Inclusion 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.

Design outcomes

Primary

MeasureTime frameDescription
Crestal bone level changes around subcrestal implants24 months after loadingRadiographic assessment of peri-implant marginal bone level changes (in millimeters) comparing narrow versus regular tie-base abutments. Measurements are taken from standardized periapical radiographs at the mesial and distal aspects of each implant, using the implant shoulder as reference.

Contacts

Primary ContactMohammed El-Sawy, PhD
Dr_sawy@windowslive.com00201061314522
Backup ContactMohammed T. Khater, PhD
MohamedKhaterdentalsmile1234@gmail.com00201003854552

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026