An interventional study of Bio-Oss Collagen and Mucograft Seal in Tooth Loss / Rehabilitation, Tooth Extraction and Alveolar Bone Loss, sponsored by University of Bern. Not yet recruiting at 1 site in Switzerland. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-08-06.
Sponsored by University of Bern · Not applicable, Interventional, and Treatment
This randomized controlled trial compares two provisional socket-sealing concepts following single non-molar tooth extraction and alveolar ridge preservation: a fixed, tooth-supported, 3D-printed ovate pontic provisional restoration providing active soft tissue support (test) versus a removable Essix-type provisional restoration without intentional soft tissue contact combined with a porcine collagen matrix seal (control). Both groups receive alveolar ridge preservation using a deproteinized bovine bone mineral with 10% collagen. The primary endpoint is interproximal soft tissue height at 5 months, adjusted for baseline, assessed by digital superimposition of intraoral surface scans. Up to 40 participants will be enrolled at the University of Bern School of Dental Medicine.
Following tooth extraction, dimensional changes of the alveolar ridge and loss of interproximal soft tissue height may compromise esthetic and prosthetic outcomes. Alveolar ridge preservation attenuates hard tissue resorption but provides limited active support for the overlying soft tissues during healing. An ovate pontic provisional restoration may provide active soft tissue support and thereby help preserve interproximal soft tissue height. To date, no randomized controlled trial has compared a fixed ovate pontic provisional restoration with a removable non-contact Essix provisional restoration in the context of alveolar ridge preservation.
This is a single-center, open-label, confirmatory, randomized controlled trial with two parallel groups and 1:1 allocation. An adaptive design with an internal pilot phase (n=20) and blinded sample size re-estimation based on the residual variance of the primary endpoint is applied, up to a predefined maximum of 40 participants.
All participants undergo minimally traumatic, flapless single non-molar tooth extraction and alveolar ridge preservation with Bio-Oss Collagen. Test group: socket sealing by a fixed, 3D-printed ovate pontic provisional restoration providing active soft tissue support. Control group: socket sealing with Mucograft Seal plus a removable Essix-type provisional restoration positioned without intentional soft tissue contact.
Follow-up visits are performed at 2 weeks, 4 weeks, and 5 months. At baseline (T0) and at 5 months, intraoral surface scans, clinical photographs, cone-beam computed tomography, and patient-reported outcomes are collected. The between-group treatment effect on the primary endpoint is estimated using ANCOVA with the 5-month value as dependent variable, treatment group as fixed factor, and the baseline value as covariate; jaw is included as an additional between-subject factor.
165 studies on the registry are indexed under Tooth Loss; 44 are open to participants now.
This study's planned enrollment of 40 is above the median of 30 across 120 interventional studies indexed under Tooth Loss.
Browse Tooth Loss studies →University of Bern is the lead sponsor of 209 studies on the registry; 47 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HbA1c
A blood test of average blood sugar over the past two to three months, given as a percentage or in mmol/mol. 6.5% (48 mmol/mol) or more is the usual threshold for diabetes, normally confirmed by a second test.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hypersensitivity
An allergy, or another reaction of the immune system, to a substance. “Hypersensitivity to the study drug” means a known allergic reaction to it — not every side effect a medicine can have.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Following minimally traumatic, flapless tooth extraction, the alveolar socket is grafted with Bio-Oss Collagen. Socket sealing is achieved by a fixed, 3D-printed provisional restoration incorporating an ovate pontic design that extends approximately 2 mm apical to the mucosal margin, providing active soft tissue support to maintain interproximal papilla height and facial soft tissue contour during healing. The provisional is retained by adhesive bonding or temporary cementation on the adjacent teeth. No additional collagen matrix or sutures are placed.
Device: Bio-Oss Collagen · Procedure: Fixed 3D-printed ovate pontic provisional restoration
Following minimally traumatic, flapless tooth extraction, the alveolar socket is grafted with Bio-Oss Collagen. The socket is sealed with a porcine-derived collagen matrix (Mucograft Seal) secured with four to six single interrupted sutures, without primary closure. A removable Essix-type provisional restoration with an integrated artificial tooth is delivered; the pontic is positioned above the mucosal level without intentional soft tissue contact.
Device: Bio-Oss Collagen · Device: Mucograft Seal · Procedure: Removable Essix provisional restoration
Deproteinized bovine bone mineral with 10% collagen (Geistlich Pharma AG, Wolhusen, Switzerland). Used for alveolar ridge preservation by socket grafting after tooth extraction. CE-marked and used within the approved indication.
Also known as: Fixed ovate pontic provisional, Removable Essix provisional with collagen matrix seal
Patient-specific 3D-printed provisional restoration (PMMA or comparable clinically approved dental provisional material) incorporating an ovate pontic design. Retained by adhesive bonding or temporary cementation on the adjacent teeth. The convex, highly polished pontic extends approximately 2 mm apical to the mucosal margin and above the level of the bone graft, providing active soft tissue support.
Patient-specific 3D-printed provisional restoration (PMMA or comparable clinically approved dental provisional material) incorporating an ovate pontic design. Retained by adhesive bonding or temporary cementation on the adjacent teeth. The convex, highly polished pontic extends approximately 2 mm apical to the mucosal margin and above the level of the bone graft, providing active soft tissue support.
Patient-specific removable thermoplastic Essix-type appliance with an integrated artificial tooth. The pontic is positioned above the mucosal level without intentional soft tissue contact. Delivered at the surgical visit after socket sealing with the collagen matrix.
Interproximal soft tissue height at 5 months
Interproximal soft tissue height at 5 months, calculated per participant as the mean of the mesial and distal measurements and expressed in millimeters. Measurements are obtained by digital superimposition of baseline and 5-month intraoral surface scans (Geomagic Control X, 3D Systems) by an independent, calibrated examiner. The between-group treatment effect is estimated using ANCOVA with the 5-month value as the dependent variable, treatment group as a fixed factor, baseline value as a covariate, and jaw as an additional between-subject factor.
Time frame: Baseline (T0) and 5 months after tooth extraction
Midfacial mucosal level at 5 months
Vertical position of the midfacial mucosal margin at 5 months (mm), assessed on superimposed intraoral surface scans. The between-group difference is estimated using ANCOVA with the 5-month value as dependent variable and the baseline value as covariate.
Time frame: Baseline (T0) and 5 months
Horizontal ridge contour at 5 months
Horizontal ridge contour at 5 months (mm) at 1, 3, and 5 mm apical to the baseline mucosal reference, assessed on superimposed intraoral surface scans. Baseline-adjusted analysis at each level.
Time frame: Baseline (T0) and 5 months
Mucosal thickness at 5 months
Mucosal thickness at 5 months (mm) at 1, 3, and 5 mm apical to the baseline mucosal reference. Baseline-adjusted analysis at each level
Time frame: Baseline (T0) and 5 months
Volumetric soft tissue at 5 months
Volumetric soft tissue measurement at 5 months (mm3) within the defined region of interest, assessed on superimposed intraoral surface scans. Baseline-adjusted analysis.
Time frame: Baseline (T0) and 5 months
Alveolar hard tissue volume at 5 months
Volumetric measurement of alveolar hard tissue at 5 months (mm3), assessed on superimposed CBCT data. Baseline-adjusted analysis.
Time frame: Baseline (T0) and 5 months
Alveolar hard tissue contour at 5 months
Linear measurement of alveolar hard tissue contour at 5 months (mm), assessed on superimposed CBCT data. Baseline-adjusted analysis.
Time frame: Baseline (T0) and 5 months
Postoperative discomfort (VAS)
Postoperative discomfort assessed on a 100-mm visual analogue scale, ranging from 0 mm (no discomfort) to 100 mm (worst imaginable discomfort).
Time frame: 2 weeks and 4 weeks after tooth extraction
Patient satisfaction with function (VAS)
Patient-rated satisfaction with the function of the provisional restoration, assessed on a 100-mm visual analogue scale, ranging from 0 mm (completely unsatisfied) to 100 mm (completely satisfied).
Time frame: 5 months
Patient satisfaction with esthetics (VAS)
Patient-rated satisfaction with the esthetics of the provisional restoration, assessed on a 100-mm visual analogue scale, ranging from 0 mm (completely unsatisfied) to 100 mm (completely satisfied).
Time frame: 5 months
Patient satisfaction with comfort (VAS)
Patient-rated satisfaction with the comfort of the provisional restoration, assessed on a 100-mm visual analogue scale, ranging from 0 mm (completely unsatisfied) to 100 mm (completely satisfied).
Time frame: 5 months
Overall treatment satisfaction (VAS)
Patient-rated overall satisfaction with the treatment received, assessed on a 100-mm visual analogue scale, ranging from 0 mm (completely unsatisfied) to 100 mm (completely satisfied).
Time frame: 5 months
Willingness to undergo the same procedure again (VAS)
Patient-rated willingness to undergo the same procedure again, assessed on a 100-mm visual analogue scale, ranging from 0 mm (definitely not) to 100 mm (definitely yes).
Time frame: 5 months
Oral Health Impact Profile (OHIP-G14)
German version of the Oral Health Impact Profile, 14-item version. Summary score range 0 to 56; higher scores indicate worse oral health-related quality of life.
Time frame: Baseline (T0) and 5 months
Geriatric Oral Health Assessment Index (GOHAI)
German version of the Geriatric Oral Health Assessment Index. Summary score range 12 to 60; higher scores indicate better oral health-related quality of life.
Time frame: Baseline (T0) and 5 months
Adverse events and provisional-related complications
Occurrence and rate of adverse events, including postoperative infection, impaired wound healing, soft tissue dehiscence, loss or displacement of the bone substitute or collagen matrix, allergic or hypersensitivity reactions, pressure-induced mucosal lesions, debonding of the fixed provisional restoration, or irritation related to the Essix provisional.
Time frame: Up to 5 months
Plan to share: No — Individual participant data will not be publicly shared. The informed consent and data protection framework of this trial do not provide for unrestricted public sharing of coded participant-level data. Aggregated study results will be published in a peer-reviewed journal and posted in the Swiss National Clinical Trials Portal (SNCTP) and on ClinicalTrials.gov in accordance with ClinO Art. 65a.
Start is estimated for Oct 2026; primary completion for Feb 2029, 28 months later.
Of 71 non-industry interventional studies with no phase under Tooth Loss, half reached primary completion within 28 months of starting (the median), counting those still running; a quarter within 12 and three quarters within 48. This study's planned 28 months is close to that.
Counting every sponsor, half of 77 studies reached it within 28 months; a quarter within 12 and three quarters within 48.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Jul 2026. You cannot join it, but the record below documents what was studied.
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