Clinical and Dimensional Outcomes of Sealing Socket Abutment Combined to Alveolar Ridge Preservation

objectives

The aim of this study was to assess the implant outcomes as well as hard and soft tissue dimensional changes of immediate implant placement in posterior sites using a custom-made sealing socket abutment (SSA) combined to alveolar ridge preservation (ARP).

Material and methods

Twenty posterior teeth were immediately replaced with implants in 20 patients. The remaining sockets were filled with Deproteinized Bovine Bone Mineral. Based on intra-oral scanners (IOS), custom-made SSAs were placed the same day. CBCT and IOS were performed to monitor hard and soft tissue dimensional changes. Moreover, implant survival rate, peri-implant bone changes, peri-implant health and pink esthetic score were recorded at 1 year, 3years and 5 years.

Study population

Hopeless maxillary or mandibular molars with tooth anatomy and bone anchorage allowing an immediate implant procedure: apical bone height of at least 5 mm or presence of interradicular septum, socket with intact bone walls, absence a large apical periodontitis, Patients needing tooth replacement in the posterior region (molars) will be recruited from the Department of Periodontology and Oral and Implant Surgery of the University of Liège, Belgium.

Procedures

After a local anesthesia, one of the two experienced surgeons (LF or LG) proceeded to the least traumatic extraction of the concerned tooth. The consecutive drills for implant placement were carried out while considering the future position of the crown for a screw- retained restoration. Twenty BLX implants (Roxolid®, SLAactive®, Institut Straumann AG) were placed flapless with a sufficient apical or septum anchorage and the insertion torque was recorded. The gap around the implant was filled with deproteinized bovine bone mineral (DBBM) (cerabone®, botiss biomaterials GmbH).

Just after the implant placement, an intra-oral scan (IOS) (Trios 3®, 3-Shape) with a scanbody connected onto the implant platform was performed and sent to the dental laboratory to digitally design (Dental Wings®) a customized healing abutment. The SSA was then milled (CARES®, Institut Straumann AG) from a block of PEEK (JUVORATMPEEK, JUVORATM Ltd. National Distributor: Institut Straumann AG), cemented to a titanium abutment (Variobase®, Institut Straumann AG) and provided to the patient on the same day. During manufacturing of the SSA, a conventional healing abutment was screwed on the implant and a collagen sponge (Collaplug®) was provisionally placed buccally to protect the exposed biomaterial until the placement of the SSA. A standardized parallel peri-apical radiograph using a custom-made film holder was taken in order to record the baseline bone level. Each patient was instructed to rinse twice daily with an aqueous solution of 0.2% chlorhexidine (Corsodyl®, GSK) and to avoid brushing of the area until the first recall 10-12 days later. Anti-inflammatories (Ibuprofen® 600 mg) and additional analgesics (Paracetamol® 500 mg) were prescribed and taken according to the patient's needs. If the surgeon deemed it necessary, an anti- biotic was prescribed (Amoxicillin® 500mg 3x/day during 5 days). Three months after implantation, the abutment was removed, the osseointegration of the implant was checked and the final lithium aluminosilicate ceramic reinforced with lithium disilicate monolithic crown (n!ce® glass-ceramic block, Institut Straumann AG) based on the initial IOS was cemented to a titanium abutment (Variobase®, Institut Straumann AG) and placed. The transmucosal design from the SSA was replicated on the final crown. Follow-up evaluations and data recording will be performed 7-10 days, 3 months, 6 months, 12 months, 3years and 5years after the surgery.

Eligibility Criteria:
Inclusion Criteria:

* good general health (ASA I/II),
* more than 18 years old,
* non smoker,
* one hopeless tooth,
* healthy periodontal condition,
* the presence of at least 2 mm of keratinized gingiva,
* adequate plaque control (FMPS ≤ 25%), adequate bone quantity in the septum if present and at least 5 mm of bone in the apical region

Exclusion Criteria:

* auto-immune disease or immunocompromised patients,
* uncontrolled diabetes,
* use of steroids or biphosphonates,
* local or systemic infection (medical treatment needed prior to entrance to the study), pregnancy or breastfeeding, alcoholism or chronically drug abuse.

Local exclusion criteria:

* bone availability requiring an angulated abutment,
* untreated local inflammation,
* cyst,
* mucosal disease or oral lesions,
* local irradiation therapy,
* oral communication with sinus after the extraction.