Brief description of the study objectives The present study aims to evaluate the effectiveness of the porcine-derived collagen matrix Derma OsteoBiol® for peri-implant soft tissue augmentation.

The objectives include:

Measuring changes in soft tissue thickness (in 3D) in the buccal region of the treated implants; Analyzing patient-reported outcomes (PROMs), namely pain and impact on oral health-related quality of life; Monitoring the stability of peri-implant tissues and aesthetic parameters over a 12-month period.

Description of the study methodology (including the expected completion date) This is a prospective, controlled, post-marketing clinical follow-up study (Phase IV), to be conducted at the Faculty of Dental Medicine of the University of Porto. The aim is to evaluate the effectiveness of the resorbable porcine-derived collagen matrix Derma OsteoBiol® for soft tissue augmentation around dental implants.

Fifteen adult participants, aged 18 years or older, will be included, presenting a need for augmentation of the keratinized mucosa at the buccal aspect of an implant previously placed in the posterior region of the maxilla or mandible. Participants must be able to understand the nature of the study, provide free and informed consent, comply with the procedures and visits defined in the protocol, and maintain good oral hygiene. The dental implant must have been placed at least six weeks prior to the start of the study, and the width of the buccal keratinized mucosa must be great than one millimeters.

Individuals with general contraindications to dental surgery, such as uncontrolled use of anticoagulants, or presenting vertical bone defects greater than three millimeters at the implant site, will be excluded. Additional exclusion criteria include: heavy smoking (more than ten cigarettes per day), presence of active periodontal or peri-implant disease, insulin-dependent diabetes mellitus, history of malignant neoplasia with treatment within the last five years, pregnancy or breastfeeding, lack of effective contraception in women of childbearing age, use of medications that affect soft tissue healing, systemic diseases interfering with connective tissue metabolism (such as autoimmune or arterial diseases), alcohol abuse, collagen allergy, participation in other clinical studies within the previous six months, inadequate oral hygiene (plaque index greater than 25%), or occurrence of any adverse event preventing continuation of treatment.

After inclusion, participants will undergo mucogingival surgery using the VISTA (Vestibular Incision Submucosal Tunnel Access) surgical technique. The Derma OsteoBiol® membrane will be pre-hydrated in sterile saline solution, trimmed, and positioned at the surgical site, and stabilized with monofilament sutures. The incision will be completely closed, avoiding membrane exposure.

Tissue thickness will be assessed through intraoral digital impressions and three-dimensional tissue volume analysis, with measurements performed before surgery and at 1, 3, 6, and 12 months after the intervention. These images will be superimposed using stable anatomical reference points to ensure accuracy and will be analyzed by a calibrated and independent examiner. Clinical data will also be collected throughout the study, including measurements of keratinized mucosa width, probing depth, clinical attachment level, presence of bleeding on probing, plaque index, and gingival recession. Standardized clinical photographs will be obtained at each visit for documentation of soft tissue status and aesthetic evaluation.

Patient perspective will be assessed using the Oral Health Impact Profile questionnaire (OHIP-14) and a numerical pain rating scale, applied at specific follow-up time points. The occurrence of adverse events will be continuously monitored and recorded in accordance with applicable legal and regulatory standards.

This study will be conducted in accordance with the Declaration of Helsinki, Good Clinical Practice.

Inclusion Criteria:

• • Patients must have the ability to fully understand the nature of the proposed surgery, voluntarily consent to participate and signed the Informed Consent Form before any study related procedures are performed.

  • Agree with data collection and analyses.
  • Males or females who are a minimum of 18 years of age or older.
  • Ability to comply with study-related procedures, including maintaining good oral hygiene and attending follow-up appointments.
  • Implant placement at least 6 weeks prior to enrolment.
  • There must be a need for soft tissue augmentation in an implant side.
  • Implant located in the posterior areas of the maxilla or mandibula (molar or 2nd premolars).
  • Basic periodontal examination (BPE) score must be less than 2.
  • patients exhibiting KT width of >2 mm at the buccal aspect of the implant.

Exclusion Criteria:

• • Patients who meet any of the following exclusion criteria are not eligible for inclusion in the study.

  • General contraindications for dental and/or surgical treatment, including the use of anticoagulants.
  • Presence of a vertical bone dehiscence greater than 3 mm at the implant site, as assessed at the time of soft tissue augmentation surgery.
  • Heavy smoking habit, defined as consuming more than 10 cigarettes per day.
  • Presence of active periodontal or peri-implant disease.
  • Insulin-dependent diabetes.
  • History of malignancy, radiotherapy, or chemotherapy for malignancy within the past 5 years.
  • Women of childbearing age who are not using a highly effective method of contraception.
  • Pregnancy or breastfeeding.
  • Previous or current use of medication that affects mucosal healing in general, such as steroids or large doses of anti-inflammatory drugs.
  • Any disease or condition affecting connective tissue metabolism, such as arterial diseases in the operating area, bone metabolic disorders, or alcohol abuse.
  • Systemic diseases such as diabetes or autoimmune diseases.
  • Allergy to collagen.
  • Participation in an investigational device or drug clinical trial within the last 6 months.
  • Inadequate oral hygiene (FMPS>25%)
  • An adverse event occurred, whether or not study device related, which precluded continued treatment;

De-identified individual participant data (IPD) collected during the study, including demographic characteristics, baseline clinical data, intervention details, primary and secondary outcome measures, and adverse events data. Data dictionaries describing the variables will also be made available.

Beginning 12 months following publication of the primary results and ending 36 months after publication.

Access to de-identified individual participant data will be granted to qualified researchers upon reasonable request. Requests should include a research proposal and statistical analysis plan. Data will be shared following review and approval by the study investigators and after signing a data sharing agreement.