Comparison of Three Transmucosal Augmentation Techniques in Immediate Implant Placement

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

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.

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.

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.