Immediate Molar Implants With Customized Healing Abutments in Different Post-Extraction Socket Classes (IMPLA-CHA)

Evaluation of the Success of Immediate Implants in the Molar Region Using Individually Fabricated Healing Abutments (Sulcus Formers) in Different Classes of Post-Extraction Sockets: A Prospective Cohort Study

Immediate implant placement into a fresh extraction socket shortens overall treatment time and reduces the number of surgical procedures, but the fit between the implant and the socket walls, and the resulting soft-tissue contour, differ substantially between socket types. This study evaluates immediate implant placement in the molar and posterior region combined with an individually fabricated (customized) healing abutment, or sulcus former, that seals the socket and shapes the emergence profile from the day of surgery.

Consecutive patients with a non-restorable posterior tooth are treated with flapless atraumatic extraction, immediate implant placement, grafting of the residual gap, and a chairside customized healing abutment fabricated on a titanium temporary abutment. Participants are grouped by the class of the post-extraction socket (A, B or C) according to the interradicular septal bone available for primary stability.

Outcomes are preservation of peri-implant soft-tissue volume assessed with an intraoral scanner, preservation of alveolar bone volume assessed on cone-beam computed tomography, implant stability measured by resonance frequency analysis (ISQ) at placement and before loading, and time to definitive loading. Early wound healing on the Landry index, the degree of bone corticalization before loading, implant survival, healing-abutment complications and analgesic requirement are also recorded.

Study Overview

• Status: Recruiting
• Conditions: Tooth Loss; Alveolar Bone Loss; Jaw, Edentulous, Partially
• Intervention / Treatment: Procedure: Immediate implant placement with customized healing abutment

• Study Type: Observational
• Enrollment (Estimated): 60

Contacts and Locations

• Study Contact: Name: Lyubomir Chenchev, DMD, PhD; Phone Number: +359 887 102 516; Email: lyubomir.chenchev@mu-plovdiv.bg

Study Locations

• Bulgaria
  • Plovdiv, Bulgaria, 4000
    • Recruiting
    • Department of Dental Implantology, Faculty of Dental Medicine, Medical University - Plovdiv
    • Contact: Lyubomir Chenchev, DMD, PhD; Phone Number: +359 887 102 516; Email: lyubomir.chenchev@mu-plovdiv.bg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Consecutive adult patients attending the Department of Dental Implantology, Faculty of Dental Medicine, Medical University - Plovdiv, with a non-restorable posterior (premolar or molar) tooth indicated for extraction and suitable for immediate implant placement.

Description

Inclusion Criteria:

• Age 18 years or over
• ASA physical status I or II
• A non-restorable posterior tooth (premolar or molar) indicated for extraction: clinically unrestorable crown, advanced chronic periodontitis, failed or untreatable endodontic therapy, or vertical root fracture
• Residual bone permitting implant placement with adequate primary stability
• Able and willing to give written informed consent and to attend the follow-up schedule

Exclusion Criteria:

• ASA physical status III or higher
• Pregnancy or lactation
• Uncontrolled diabetes mellitus
• Smoking more than 10 cigarettes per day
• Drug or alcohol abuse
• Current or previous bisphosphonate or other antiresorptive therapy
• Head and neck radiotherapy
• Immunosuppression
• Anticoagulant or antiplatelet therapy where the required pre-operative preparation is declined
• Psychiatric conditions preventing compliance with the study procedures
• Known titanium allergy
• Severe bruxism
• Acute infection at the surgical site
• Advanced alveolar resorption precluding immediate implant placement

Study Plan

How is the study designed?

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Socket class A; Posterior extraction socket in which the interradicular septal bone is sufficient to house the implant, giving circumferential bone contact along its coronal part. Because a molar socket is frequently 10 mm or more across, a residual void commonly remains around the implant within the socket. Participants receive immediate implant placement with a chairside customized healing abutment.	Procedure: Immediate implant placement with customized healing abutment; Flapless atraumatic extraction with tooth sectioning and root-by-root removal, socket debridement and saline irrigation, followed by immediate placement of a MegaGen AnyRidge implant (MegaGen Implant Co., Daegu, South Korea; diameter 4.0-5.5 mm, length 8.5-11.5 mm) in a subcrestal position at the level of the septal bone. Where insertion torque of at least 35 Ncm and an implant stability quotient of at least 65 are achieved, the residual gap is grafted with equine-derived xenograft granules of 0.25 mm (Maggi Biotechnology, Andezeno, Italy) and a customized healing abutment is fabricated chairside from flowable composite on a titanium temporary abutment (Spider Web technique), hand-tightened and left free of occlusal contact. No barrier membrane is used. Definitive loading is planned at three months.
Socket class B; Posterior extraction socket in which the septal bone is sufficient to stabilise the implant but not to house it, so that part of the implant surface faces the socket rather than bone. Participants receive immediate implant placement with a chairside customized healing abutment.	Procedure: Immediate implant placement with customized healing abutment; Flapless atraumatic extraction with tooth sectioning and root-by-root removal, socket debridement and saline irrigation, followed by immediate placement of a MegaGen AnyRidge implant (MegaGen Implant Co., Daegu, South Korea; diameter 4.0-5.5 mm, length 8.5-11.5 mm) in a subcrestal position at the level of the septal bone. Where insertion torque of at least 35 Ncm and an implant stability quotient of at least 65 are achieved, the residual gap is grafted with equine-derived xenograft granules of 0.25 mm (Maggi Biotechnology, Andezeno, Italy) and a customized healing abutment is fabricated chairside from flowable composite on a titanium temporary abutment (Spider Web technique), hand-tightened and left free of occlusal contact. No barrier membrane is used. Definitive loading is planned at three months.
Socket class C; Posterior extraction socket with little or no septal bone, so that primary stability must be obtained from the peripheral socket walls and/or the bone apical to the socket. Participants receive immediate implant placement with a chairside customized healing abutment.	Procedure: Immediate implant placement with customized healing abutment; Flapless atraumatic extraction with tooth sectioning and root-by-root removal, socket debridement and saline irrigation, followed by immediate placement of a MegaGen AnyRidge implant (MegaGen Implant Co., Daegu, South Korea; diameter 4.0-5.5 mm, length 8.5-11.5 mm) in a subcrestal position at the level of the septal bone. Where insertion torque of at least 35 Ncm and an implant stability quotient of at least 65 are achieved, the residual gap is grafted with equine-derived xenograft granules of 0.25 mm (Maggi Biotechnology, Andezeno, Italy) and a customized healing abutment is fabricated chairside from flowable composite on a titanium temporary abutment (Spider Web technique), hand-tightened and left free of occlusal contact. No barrier membrane is used. Definitive loading is planned at three months.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in peri-implant soft-tissue volume	Volumetric change of the peri-implant soft tissue relative to the pre-extraction baseline, measured in cubic millimetres by superimposition of intraoral scans.	Baseline, 3 months after placement (before loading), and 2 weeks after loading
Time to definitive loading	Interval in months from implant placement to definitive prosthetic loading, determined by the pre-loading radiographic assessment and the implant stability quotient.	Up to 6 months after implant placement
Implant stability quotient (ISQ)	Implant stability measured by resonance frequency analysis on the ISQ scale from 1 to 100, where higher values indicate greater stability. Stability before loading is the criterion that determines whether the implant is loaded at three months.	At implant placement and at 3 months after placement (before loading)
Change in alveolar bone volume	Volumetric change of the peri-implant alveolar bone relative to the pre-extraction baseline, measured in cubic millimetres on cone-beam computed tomography.	Baseline and 3 months after placement (before loading)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Early wound healing	Early wound healing graded on the Landry Wound Healing Index from 1 to 5, where higher values indicate better healing.	Days 7 and 14 after surgery
Analgesic requirement	Number of participants taking the prescribed analgesic (ibuprofen L-arginine 600 mg twice daily as needed) after surgery.	First 5 days after surgery
Customized healing abutment complications	Number of participants with abutment screw loosening, fracture of the composite healing abutment, or peri-implant infection, each recorded as present or absent.	From surgery to definitive loading, up to 4 months
Implant survival	Proportion of implants in situ and functional at the latest follow-up visit.	Up to 24 months after implant placement
Peri-implant bone corticalization	Degree of corticalization of the peri-implant bone, assessed on cone-beam computed tomography using a radiological corticalization index.	3 months after placement (before loading)

Collaborators and Investigators

• Sponsor: Plovdiv Medical University
• Investigators: Principal Investigator: Tasho Gavrailov, DMD, PhD, Medical University of Plovdiv

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2024
• Primary Completion (Estimated): December 1, 2026
• Study Completion (Estimated): December 1, 2026

Study Registration Dates

• First Submitted: August 31, 2026
• First Submitted That Met QC Criteria: August 31, 2026
• First Posted (Actual): September 3, 2026

Study Record Updates

• Last Update Posted (Actual): September 3, 2026
• Last Update Submitted That Met QC Criteria: August 31, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: molar; customized healing abutment; emergence profile; cone-beam computed tomography; peri-implant soft tissue; immediate implant placement; implant stability quotient; sulcus former; post-extraction socket; socket classification
• Additional Relevant MeSH Terms: Bone Resorption; Bone Diseases; Musculoskeletal Diseases; Periodontal Atrophy; Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Jaw Diseases; Tooth Diseases; Mouth, Edentulous; Jaw, Edentulous; Alveolar Bone Loss; Tooth Loss; Jaw, Edentulous, Partially
• Other Study ID Numbers: NO-18/2025; R-KNE-55/10.11.2025 (Other Identifier: Committee on Scientific Ethics, Medical University of Plovdiv)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be made publicly available. De-identified data supporting the published analyses are available from the corresponding author on reasonable request.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No