Ovate Pontic Versus Essix Provisional After Tooth Extraction and Alveolar Ridge Preservation (Pontic-Essix) (Pontic-Essix)

Socket Sealing With a Fixed Ovate Pontic Provisional Versus a Removable Provisional Following Tooth Extraction and Alveolar Ridge Preservation: A Randomized Controlled Trial

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.

Study Overview

• Status: Not yet recruiting
• Conditions: Alveolar Bone Loss; Tooth Extraction; Alveolar Ridge Augmentation; Tooth Loss / Rehabilitation
• Intervention / Treatment: Device: Bio-Oss Collagen; Procedure: Fixed 3D-printed ovate pontic provisional restoration; Device: Mucograft Seal; Procedure: Removable Essix provisional restoration

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Nicole Schenk, Dr. med. dent.; Phone Number: +41 31 684 06 35; Email: nicole.schenk@unibe.ch
• Study Contact Backup: Name: Martin Schimmel, Prof. Dr. med. dent.; Phone Number: +41 31 684 06 35; Email: martin.schimmel@unibe.ch

Study Locations

• Switzerland
  • Canton of Bern
    • Bern, Canton of Bern, Switzerland, 3010
      • University of Bern, Department of Reconstructive Dentistry and Gerodontology
      • Contact: Nicole Schenk, Dr. med. dent.; Phone Number: +41 31 684 06 35; Email: nicole.schenk@unibe.ch

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 years or older
• ASA physical status I or II
• Requiring a single non-molar tooth extraction (incisor, canine, or premolar) in the maxilla or mandible, with planned tooth replacement
• Extraction site bounded by natural, periodontally stable adjacent teeth
• Intact alveolar socket upon extraction, or no more than one bony wall (facial, palatal, or lingual) presenting a dehiscence extending less than 50% of the total bony wall height
• Willingness and ability to comply with the follow-up protocol
• Ability to give informed consent, as documented by signature

Exclusion Criteria:

• Current smokers, or former smokers who quit less than 6 months before extraction
• Uncontrolled diabetes mellitus (HbA1c > 7.0%)
• Clinical attachment loss ≥ 2 mm at the extraction site
• Active or recent chemotherapy, or history of head and neck radiotherapy
• Current or previous bisphosphonate therapy within the past 10 years
• Immunosuppressive medication
• Active oral or systemic acute infection
• Severe hematologic disorder, hepatic or renal failure, or any clinically relevant bleeding disorder or anticoagulant medication that cannot be safely managed for the planned surgical procedure
• Pregnancy or lactation
• Known allergy or hypersensitivity to any of the study materials, including bovine-derived bone substitute, porcine-derived collagen matrix, or collagen-containing biomaterials
• Any other disease or medication that may compromise normal wound healing
• Inability to follow the study procedures (e.g., insufficient language comprehension, cognitive impairment, psychological disorder, or dementia)
• Known or suspected non-compliance
• Participation in another clinical trial that may interfere with the present study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Fixed ovate pontic provisional; 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; 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.; Other Names: Fixed ovate pontic provisional; Removable Essix provisional with collagen matrix seal; Procedure: Fixed 3D-printed ovate pontic provisional restoration; 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.
Active Comparator: Removable Essix provisional with collagen matrix seal; 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; 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.; Other Names: Fixed ovate pontic provisional; Removable Essix provisional with collagen matrix seal; Device: Mucograft 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.; Procedure: Removable Essix provisional restoration; 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	Baseline (T0) and 5 months after tooth extraction

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	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.	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	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.	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.	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.	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).	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).	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).	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).	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).	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).	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.	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.	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.	Up to 5 months

Collaborators and Investigators

• Sponsor: University of Bern
• Investigators: Principal Investigator: Nicole Schenk, Dr. med. dent., University of Bern, Department of Reconstructive Dentistry and Gerodontology; Study Chair: Martin Schimmel, Prof. Dr. med. dent., University of Bern, Department of Reconstructive Dentistry and Gerodontology; Study Director: Emilio Couso-Queiruga, PD Dr. med. dent., University of Bern, Department of Oral Surgery and Stomatology

Publications and helpful links

General Publications

• Avila-Ortiz G, Gubler M, Romero-Bustillos M, Nicholas CL, Zimmerman MB, Barwacz CA. Efficacy of Alveolar Ridge Preservation: A Randomized Controlled Trial. J Dent Res. 2020 Apr;99(4):402-409. doi: 10.1177/0022034520905660. Epub 2020 Feb 12.
• Couso-Queiruga E, Garaicoa-Pazmino C, Fonseca M, Chappuis V, Gonzalez-Martin O, Avila-Ortiz G. Interproximal Soft Tissue Height Changes After Unassisted Socket Healing vs Alveolar Ridge Preservation Therapy. Int J Periodontics Restorative Dent. 2024;44(5):520-533. doi: 10.11607/prd.6809.

Study record dates

Study Major Dates

• Study Start (Estimated): October 1, 2026
• Primary Completion (Estimated): February 1, 2029
• Study Completion (Estimated): February 1, 2029

Study Registration Dates

• First Submitted: July 31, 2026
• First Submitted That Met QC Criteria: July 31, 2026
• First Posted (Actual): August 6, 2026

Study Record Updates

• Last Update Posted (Actual): August 6, 2026
• Last Update Submitted That Met QC Criteria: July 31, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: randomized controlled trial; provisional restoration; alveolar ridge preservation; papilla; ovate pontic; socket sealing; interproximal soft tissue; digital superimposition
• Additional Relevant MeSH Terms: Bone Resorption; Bone Diseases; Musculoskeletal Diseases; Periodontal Atrophy; Periodontal Diseases; Mouth Diseases; Stomatognathic Diseases; Tooth Diseases; Alveolar Bone Loss; Tooth Loss
• Other Study ID Numbers: Pontic-Essix; 2026-01626 (Other Identifier: Swiss Ethics Committee (BASEC))

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: 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.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No