Comparison of Three Transmucosal Augmentation Techniques in Immediate Implant Placement

Official title

A Three-arm Randomized Controlled Trial Comparing Transmucosal Augmentation Techniques in Immediate Implant Placement

Overview

Patients undergoing single immediate implant placement (IIP) in the premaxilla will be invited to participate in this randomized controlled trial (RCT). Prior to surgery, a small- field low-dose cone beam computed tomography (CBCT) is taken to verify the integrity of the facial bone wall and an adequate amount of apical and palatal bone availability for implant anchorage. 54 patients will be randomly assigned to either conventional connective tissue graft (C-CTG), scarf tissue graft (S-CTG) or dual zonde conept (DZ). Sealed envelopes are prepared for that purpose, of which 18 are internally labeled as C-CTG, 18 as S-CTG and 18 as DZ. Following IIP, a sealed envelope will be opened to reveal the treatment concept. Successful regeneration (primary outcome) is achieved when the combination of socket grafting and transmucosal augmentation (C-CTG or S-CTG or DZ) would be able to counteract any buccal soft tissue loss at level -1 mm. It is assessed on the basis of superimposed CBCTs taken pre-operatively and at one-year follow-up. Secondary outcomes include: horizontal buccal bone loss, vertical buccal bone loss, increase in buccal soft tissue thickness, patient-reported outcomes, plaque, bleeding on probing, probing depth, marginal bone loss, change in buccal soft tissue profile, midfacial soft tissue level, mesial and distal papilla level, Pink Esthetic Score.

Detailed description

This study is a three-arm randomized controlled trial comparing conventional connective tissue grafting (C-CTG) with two alternative soft-tissue augmentation approaches-scarf CTG (S-CTG) and the dual-zone technique (DZ)-in patients receiving single immediate implant placement in the anterior maxilla. The primary objective is to determine which method results in the highest proportion of sites showing successful regeneration 1 mm below the implant shoulder. Secondary outcomes assess clinical parameters, patient-reported pain and medication use, hard- and soft-tissue dimensional changes, and esthetic scores.

Eligible participants are adults with good oral hygiene and an anterior maxillary tooth requiring extraction with adequate bone support. Exclusion criteria include pregnancy, systemic disease, smoking, active infection, periodontal disease, and extensive gingival asymmetry. Fifty-four patients will be randomized equally to the three intervention groups; allocation is concealed and outcome assessors are blinded.

All patients receive immediate implant placement with socket grafting. The three groups differ only in the soft-tissue augmentation method: C-CTG involves placing a connective tissue graft in a buccal pouch; S-CTG uses a smaller graft fixed at the transmucosal aspect without a pouch; DZ relies on graft condensation beneath the soft tissue without a connective tissue graft. Standard postoperative care is provided in all groups.

Hard- and soft-tissue changes are assessed using cone-beam CT, clinical measurements, intra-oral scans, and standardized photography at baseline and follow-up visits. Successful regeneration is defined by maintenance of buccal soft tissue at the specified reference level. Patient-reported postoperative pain and analgesic use are recorded after one week. Esthetic outcomes are evaluated using a validated scoring system at 1- and 5-year follow-up.

Data will be analyzed using appropriate statistical tests for group comparisons, including mixed models for tissue changes, Fisher's exact test for the primary outcome, and non-parametric tests for variables that are not normally distributed. A two-sided significance level of 5% is applied throughout.

Interventions

• Procedure Conventional connective tissue graft after immediate implant placement
  A pouch is made in the buccal mucosa extending 3 mm below the buccal bone crest. Thereupon, a free gingival graft is harvested from the palatal mucosa and de-epithelialized. The CTG is brought into the pouch and fixed with two single sutures onto the buccal mucosa. A healing abutment is installed, which is replaced by a provisional implant crown 2 days later. Sutures are removed 1 week after the surgery.
• Procedure Scarf connective tissue graft after immediate implant placement
  No pouch is made in the recipient site. A free gingival graft is harvested from the palatal mucosa and de-epithelialized. The small CTG is fixed at the transmucosal aspect onto the buccal mucosa. A healing abutment is installed, which is replaced by a provisional implant crown 2 days later. Sutures are removed 1 week after the surgery.
• Procedure Dual zone concept after immediate implant placement
  DBBM is applied and condensed up to the level of the buccal soft tissue margin. A healing abutment is installed, which is replaced by a provisional implant crown 2 days later. Usually, sutures are not needed in this group, unless minimal papilla opening was required to extract the tooth. In that case, sutures will be removed after 1 week.

Primary outcome measures

• Succesful regeneration (%) [Time frame: 1-, 5 year]

Secondary outcome measures (12)

• Horizontal buccal bone loss -1, -3 and -5 (mm) [Time frame: 1-, 5 year]
• Vertical bone loss (mm) [Time frame: 1-, 5 year]
• Increase in buccal soft tissue thickness (mm) [Time frame: 1-, 5 year]
• Patient-reported outcomes [Time frame: 1-, 5 year]
• Plaque (%) [Time frame: 1-, 5 year]
• Bleeding on probing (%) [Time frame: 1-, 5 year]
• Probing depth (mm) [Time frame: 1-, 5 year]
• Marginal bone loss (mm) [Time frame: 1-, 5 year]
• Change in buccal soft tissue profile (mm) [Time frame: 1-, 5 year]
• Change in midfacial soft tissue level (mm) [Time frame: 1-, 5 year]
• Change in mesial and distal papilla level (mm) [Time frame: 1-, 5 year]
• Pink Esthetic Score [Time frame: 1-, 5 year]

Eligibility criteria

Inclusion criteria

• At least 20 years old
• Good oral hygiene defined as full-mouth plaque score ≤ 25%
• Presence of an incisor, cuspid or premolar in the maxilla that needs to be extracted for any reason with at least one neighboring tooth present
• At least 3 mm bone available at the apical or palatal aspect of the alveolus as assessed on CBCT to ensure primary implant stability
• Intact buccal bone wall (type I) or limited buccal bone dehiscence (type IIa or IIb) at the time of extraction
• Written informed consent.

Exclusion criteria

• Pregnancy
• Systemic diseases
• Smoking; suppuration
• > 1 mm gingival asymmetry between the failing and contralateral tooth
• Untreated periodontal disease
• Untreated caries lesions.

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

Double blind

Primary purpose

Treatment

Study locations

Belgium · 1 center

• Ghent University Hospital — Ghent

Publications

• Zuiderveld EG, van Nimwegen WG, Meijer HJA, Jung RE, Muhlemann S, Vissink A, Raghoebar GM. Effect of connective tissue grafting on buccal bone changes based on cone beam computed tomography scans in the esthetic zone of single immediate implants: A 1-year randomized controlled trial. J Periodontol. 2021 Apr;92(4):553-561. doi: 10.1002/JPER.20-0217. Epub 2020 Sep 11. PMID 32918332
• Wanis RW, Hosny MM, ElNahass H. Clinical evaluation of the buccal aspect around immediate implant using dual zone therapeutic concept versus buccal gap fill to bone level: A randomized controlled clinical trial. Clin Implant Dent Relat Res. 2022 Jun;24(3):307-319. doi: 10.1111/cid.13091. Epub 2022 May 4. PMID 35507735
• Tonetti MS, Jung RE, Avila-Ortiz G, Blanco J, Cosyn J, Fickl S, Figuero E, Goldstein M, Graziani F, Madianos P, Molina A, Nart J, Salvi GE, Sanz-Martin I, Thoma D, Van Assche N, Vignoletti F. Management of the extraction socket and timing of implant placement: Consensus report and clinical recommendations of group 3 of the XV European Workshop in Periodontology. J Clin Periodontol. 2019 Jun;46 Sup PMID 31215112
• Slagter KW, Meijer HJA, Hentenaar DFM, Vissink A, Raghoebar GM. Immediate single-tooth implant placement with simultaneous bone augmentation versus delayed implant placement after alveolar ridge preservation in bony defect sites in the esthetic region: A 5-year randomized controlled trial. J Periodontol. 2021 Dec;92(12):1738-1748. doi: 10.1002/JPER.20-0845. Epub 2021 Apr 3. PMID 33724473
• Sicilia-Felechosa A, Pereira-Fernandez A, Garcia-Lareu J, Bernardo-Gonzalez J, Sicilia-Blanco P, Cuesta-Fernandez I. Flapless immediate implant placement and provisionalization in periodontal patients: A retrospective consecutive case-series study of single-tooth sites with dehiscence-type osseous defects. Clin Oral Implants Res. 2020 Mar;31(3):229-238. doi: 10.1111/clr.13559. Epub 2020 Jan 20. PMID 31755601
• Seyssens L, Eghbali A, Cosyn J. A 10-year prospective study on single immediate implants. J Clin Periodontol. 2020 Oct;47(10):1248-1258. doi: 10.1111/jcpe.13352. Epub 2020 Sep 2. PMID 32748983
• Seyssens L, Eeckhout C, Cosyn J. Immediate implant placement with or without socket grafting: A systematic review and meta-analysis. Clin Implant Dent Relat Res. 2022 Jun;24(3):339-351. doi: 10.1111/cid.13079. Epub 2022 Mar 21. PMID 35313067
• Seyssens L, De Lat L, Cosyn J. Immediate implant placement with or without connective tissue graft: A systematic review and meta-analysis. J Clin Periodontol. 2021 Feb;48(2):284-301. doi: 10.1111/jcpe.13397. Epub 2020 Nov 20. PMID 33125754

Identifiers

NCT: NCT06820489 · ONZ-2024-0529

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗