Thin Gingiva
Conditions
Keywords
Soft tissue management, Dental implant, Collagen matrix, Connective tissue graft, Split thickness flap, Full thickness flap
Brief summary
Randomized, outcome assessor and data analyst blinded, single center trial with four parallel arms and a 1:1:1:1 allocation ratio, with the aim of comparing which combination of bilaminar technique (split vs. full thickness flap) and graft type (autogenous or xenogeneic) provides better clinical, aesthetic, morphological, vascular and patients related outcomes, when augmenting the buccal peri-implant mucosa at the reopening of submerged implant fixtures
Detailed description
This randomized four parallel arms controlled clinical trial with blinded outcome assessment and data analysis aims to establish which combination of bilaminar technique (split vs. full thickness flap) and graft type (autogenous subepithelial connective tissue graft vs. volume stable collagen matrix) provides better clinical, aesthetic, morphological, vascular and patients related outcomes, when augmenting the buccal peri-implant mucosa at the reopening of submerged implant fixtures. The primary outcome is the gain in soft tissue thickness (standardised measurement at baseline, after surgery, at 1m and 6m). Secondary outcomes include changes in tissue volume (intraoral scans at baseline, post-op, 14d, 1m, 6m), RAL and KTW (clinical measurements at baseline, 1m, 6m), tissue color integration (∆E at 1m and 6m), and PROMS (7d, 14d, 30d). Exploratory outcomes include tissue morphology (histology at 1m,2m,4m,6m), microcirculation (Doppler flowmetry at pre-op, 7d, 14d, 1m) and revascularization (IHC at 1m,2m,4m,6m). A figure of 10 subjects per group was obtained for a 0,3mm difference in tissue thickness increase (SD 0,23mm), using 80% power, alpha 0.05, and a 10% drop-out rate. Patients will be randomly allocated to four groups: test (STF+VCM), control 1 (FTF+VCM), control 2 (SFT+CTG), control 3 (FTF+CTG). Patients will be the unit of analysis and ANOVA (normality) or Kruskall-Wallis (no normality) tests will be performed setting the significance level at p \< 0.05.
Interventions
PROCEDURESplit thickness flap
Palatally displaced crestal incision at the edentulous site, combined with the split thickness elevation of a buccal flap, extended to the sulcus of the adjacent mesial and distal tooth. Flap elevation performed with a micro-blade, in a buccal and apical direction, for approximately 15mm apical to the crestal incision.
PROCEDUREFull thickness flap
Palatally displaced crestal incision at the edentulous site, combined with the full thickness elevation of a buccal flap, extended to the sulcus of the adjacent mesial and distal tooth. Flap elevation performed with a fine periosteal elevator, in a buccal and apical direction, for approximately 15mm apical to the crestal incision.
PROCEDUREAutogenous sub epithelial connective tissue graft
Harvest of a sub epithelial connective tissue graft using a double incision technique, approximately 2-3 mm apical to the palatal gingival margins of the first and second premolars. Graft dimension standardised as 10mm (mesio-distally) by 6-8mm (apico-coronally) by 1,5mm (thickness). Graft stabilised at the inner aspect of the buccal flap, 1mm apical to the flap margin, using one mesial and one distal horizontal mattress sutures.
PROCEDUREVolume stable collagen matrix
Geistlich Fibro-Gide® matrix shaped at a standardised dimension of 10mm (mesio-distally) by 6-8mm (apico-coronally) by 6mm (thickness). Matrix stabilised at the inner aspect of the buccal flap, 1mm apical to the flap margin, using one mesial and one distal horizontal mattress sutures.
Sponsors
Osteology Foundation
Universidad Complutense de Madrid
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Any male or female adult (≥ 18 year old) patient from the University Complutense of Madrid, being able to sign an informed consent form, presenting a submerged dental implant scheduled to undergo a second stage surgery, which is bounded mesially or distally by a remaining natural tooth, and exhibits a lack of buccal soft tissue volume, will be potentially eligible for this trial. The case definition for a lack of buccal soft tissue volume will be the presence of a thin buccal mucosa (\< 2mm) or a minor volumetric contraction of the alveolar process (flat or concave buccal mucosal profile at the edentulous area).
Exclusion criteria
Patients fitting to all the above inclusion criteria will be not included in the study if unable to attend to the study-related procedures (including the follow-up visits) or if one or more of the following systemic or local
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Buccal soft tissue thickness | before surgery, after surgery, 1 month after surgery, 6 months after surgery | Changes in the thickness of the buccal peri-implant mucosa, measured with trans-gingival probing. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Attachment level | baseline, after surgery, 1 month after surgery, 6 months after surgery | Relative attachment level (implant) and clinical attachment level (adjacent tooth) measured with a standardised UNC-15 probe. |
| Colorimetric integration | 1 month after surgery, 6 months after surgery | Colorimetric integration of the augmented buccal peri-implant mucosa, relative to the buccal attached gingiva of the mesial and distal adjacent tooth, quantified throughout the ∆E score, calculated on standardised digital photographs. |
| Patients related outcome measures | 7 days after surgery, 14 days after surgery, 1 month after surgery, 6 months after surgery | Patients pain and discomfort with respect to the procedure evaluated with the short form of the McGill pain questionnaire (SF-MPQ). |
| Microcirculation of the grafted area | before surgery, after surgery, 7 days after surgery, 14 days after surgery, 1 month after surgery, 6 months after surgery | Microcirculation of the treated area evaluated with a laser Doppler flowmeter. |
| Morphology of the grafted area | 1 month after surgery or 2 months after surgery or 4 months after surgery or 6 months after surgery | Descriptive histology performed on paraffin embedded sections from buccal gingival specimens, stained with hematoxylin-eosin. |
| Volume changes | before surgery, after surgery, 14 days after surgery, 1 month after surgery, 6 months after surgery | Changes in the size of the buccal peri-implant tissues and in their volume distribution, measured with a digital volumetric analysis. |
| Full mouth Plaque score | baseline, after surgery, 1 month after surgery, 6 months after surgery | Full muouth plaque score measured with a standardised UNC-15 probe. |
| Full mouth Bleeding score | baseline, after surgery, 1 month after surgery, 6 months after surgery | Full mouth bleeding score measured with a standardised UNC-15 probe. |
| Keratinised tissue width | baseline, after surgery, 1 month after surgery, 6 months after surgery | Keratinised tissue width measured with a standardised UNC-15 probe. |
| Bleeding on probing | baseline, after surgery, 1 month after surgery, 6 months after surgery | Presence/absence of bleeding on probing at the treated implant measured with a standardised UNC-15 probe. |
| Modified Plaque index | baseline, after surgery, 1 month after surgery, 6 months after surgery | Presence/absence of plaque at the treated implant |
| Revascularization and reinnervation of the grafted area | 1 month after surgery or 2 months after surgery or 4 months after surgery or 6 months after surgery | Immune histochemistry performed on paraffin embedded, hematoxylin-eosin stained sections using markers of tissue revascularization and reinnervation. |
Countries
Spain
Outcome results
None listed