sealing socket abutment for immediate implant placement and gum preservation

Sealing Socket Abutment: a novel digitalized strategy for immediate implant placement in molar sites

A clinical cases by our Community member Dr Gary Finelle.

 

Immediate implant placement after extraction of a molar is an attractive treatment alternative for the significant clinical benefits it provides to the patient, as well as for the dentist:
• Reduction of number of surgeries
• Reduction of overall length
• Reduction of morbidity
Many studies have reported similar implant survival rates when implantation is performed immediately after extraction (98.8%) or on healed site (99%) (Atieh 2010). Although the literature shows high survival rates, immediate implantation in molar sites must be carried out within favourable clinical conditions (attached gingival, buccal plate…) in combination with well controled technical procedures (ideal three-dimensional position, primary stability, Primary closure). One of the major challenges one clinician can face while performing immediate placement on molar site, is the ability of obtaining a hermetic primary closure of the soft tissue. This technical skill is nearly always combined with invasive surgical procedures and significant post op recovery (displacement of the muco-gingival line, periosteal releasing incision, flaps, sutures, membrane stabilization…).
To reduce invasiveness as well as technique sensitivity of the procedure the protocol illustrated in this article discusses the use of an anatomical Sealing Socket Abutment (SSA) (Finelle 2017, Finelle 2019) designed and manufactured using CAD-CAM technology to preserve peri-implant hard and soft tissue structure. The aims of the SSA are:
– To mechanically seal the surgical site following the outline of the extraction socket with its anatomical design
– To stabilize the blood clot and to favor bone regeneration space for the substitute material (Retzepi 2010)
– To support soft tissues to prevent them from collapsing during healing time.
– To develop an ideal prosthetic emergence profile, modeled on the anatomy of the existing tooth (Chu 2012).

fractured upper first molar

Fig.1

A 45 years old patient presented at our clinic for consultation appointment. She complained about intense pain upon mastication in the area of 26. Clinical and radiographic examinations showed a clear vertical root fracture splitting mesial and distal fragment all the way to the inter-radicular area. The extraction of the tooth was unequivocally indicated as the only treatment alternative.

preserved extraction socket of upper first molar

Fig.2

Immediate implant placement after extraction combined with customized Sealing Socket Abutment (SSA) will be implemented.
Minimally invasive extraction is a crucial step for succeeding in this protocol. In order to preserve surrounding structures (remaining inter-radicular bone septum, external alveolar table, soft tissue), so specific care and attention was paid while extracting the tooth during instrumentation and tissue manipulation. Once the extraction was successfully performed, accurate debridement and cleaning of the alveolar socket associated with a generous saline solution irrigation was done.

implant pin for prosthetically oriented implant placement

Fig.3

A prosthetically-driven intraseptal drilling was executed to obtain an implant anchorage as close to ideal as possible. Subsequently, an implant (Straumann TL WN 4.8 x 8 – SLAactive ) was inserted with a satisfying insertion torque (25 N/cm).

bone graft material for periimplant socket preservation

Fig.4

The freshly implanted alveolar socket is filled with slow-resorption bone substitute (xenograft type, Cerabone, Botiss) for socket preservation. Another implant was placed at #27 with a flapless technique.

scan body for digital implant impression for custom abutment

Fig.5

To obtain closure of the socket at the time of extraction, an innovative protocol has been established to allow digital impression and immediate custom CAD-CAM SSA abutment at the time of the surgery.
A scan body was connected onto the platform of the implant to allow the intra-oral scanner (Omnicam, Sirona) to capture the 3D position of the implant. Immediately after acquisition, the digital impression was exported into the labside design prosthetic platform (Inlab Sirona).

digital impression of implant with open socket for fabrication of sealing socket abutment

Fig.6

Digital impression (Omnicam, Cerec) was then sent to the lab for adequate design of the Sealing Socket Abutment (InLab, Sirona) (Laboratoire Eric Berger).

sealing socket abutment for tissue preservation after immediate implant placement

Fig.7

Fabrication of the SSA was outsourced to a lab milling system (MCX5, Sirona) (Laboratoire Eric Berger).
In order to optimize biological response, a bloc of PEEK material (LuxaCam PEEK, DMG) was selected because of its biocompatibility, as well as its biomechanical properties. While milling, a standard healing abutment and a sterile gauze was placed on the surgical site and post-operative recommendations were given to the patient. After milling, adhesive cement (Multilink abutment, Ivoclar) was used to assemble the SSA onto the Ti-Base (Variobase C, Straumann). The overall fabrication and post processing time took about 30 minutes.

implant-screwed sealing socket abutment

Fig.8

Then the SSA was screwed onto the implant (with a manual insertion torque of 10-15N/cm) to support surrounding soft tissues and to provide a barrier for bone grafting material without the use of a biological membrane (Tarnow, dualzone). Beyond its role of a mechanical barrier, the customized abutment allows the stabilization of the blood clot embedded with filling material within a confined space surrounded by bone.

lateral view of sealing socket abutment gum support

Fig.9

The emerging part of the Ti-base can be sectioned, the screw access is isolated by a layer of teflon and then sealed with a light curing resin (Telio Inlay, Ivoclar). Immediately after the surgery, post-operative peri-apical radiographs were taken to verify the proper position of the implant.

healed tissues with sealing socket abutment for socket and gum preservation

Fig.10

Aspect of the soft tissues after 15 days. The healing is favorable and no inflammation is detected upon clinical examination of the surgical area. The SSA plays as a mechanical barrier guiding soft tissue re-epithelialization during the healing phase.

healthy anatomical mucosal tunnel of molar for implant-supported fdp

Fig.11

Removal of the abutment at the time of impression showed a healthy trans-mucosal portion and anatomical shape in the prosthetic emergence area. A digital impression (Omnicam, Cerec, Sirona) was taken to fabricate the implantsupported restoration.

screw-retained crowns on implants

Fig.12

Final implant screw-retained restorations were designed (Cerec 4.4) and milled out of monolithic zirconia block (Katana, Noritake). The emergence of the implant screw axis allowed for a screw-retained prosthesis. We can notice the dimensional buccal volume discrepancy between #26 and #27 due to soft tissue collapse of #27 (healed site) as opposed to preservation of buccal contour through SSA strategy on #26 (immediate site).

zirconia crowns on upper molars

Fig.13

Final insertion torque (35 N/cm) was applied, and the access hole was covered with restorative composite (Gænial A2, GC). A post-operative periapical radiograph was taken to verify the seating and marginal integrity after insertion.

lateral view of implant-supported molar crowns

Fig.14

The clinical view at 1.5 year follow-up shows a nice biological integration and stability of implant restoration #26. No biological or technical complications were reported. Clinical assessment showed a stable position and volumes of soft tissues (buccal contour and papillae). The use of the SSA abutment helps maintain gingival environment in the edentulous zone and seems to limit the post-extraction resorption phenomenon described in the literature.
Interestingly enough, on implant #27, This picture also emphasizes the well described “implant look” often observed after implantation on a collapse healed site.

Conclusions

Surgically, this CAD-CAM device behaves as a mechanical barrier which ensures stabilization of the blood clot into a confined alveolar socket space which seems favorable for regeneration process. The SSA aims to “sealing” the socket without the use of invasive techniques such as flaps, incisions and sutures. As there is no attempt for primary closure procedure, the muco-gingival junction is not displaced and papillary architecture is maintained at its original and anatomical position. Consequently, post-operative discomfort is expected to be very low.
From a prosthetic point of view, the trans-mucosal tunnel is adequately shaped to emerge with a cervical margin in accordance with the anatomy of the previously existing natural crown. This allows to create (or maintain) soft tissue thickness around the implant platform. Peek material appears to be an ideal material for SSA abutment production as it provides high biocompatibility and biomechanical properties and ease and speed of milling.
As more and more clinics and dental offices are equipped with an in-house milling solution or cooperate with a neighbor lab, the protocols detailed in this article aims to offer a simplified and immediate workflow for single molar implant treatment (from extraction until final crown delivery) by reducing the length of treatment, the number of surgeries, and clinical steps and morbidity.

Bibliography

1. Atieh MA, Payne AG, Duncan WJ, de Silva RK, Cullinan MP. Immediate placement or immediate restoration/loading of single implants for molar tooth replacement: a systematic review and meta-analysis. Int J Oral Maxillofac Implants. 2010;25:401–15
2. Finelle G, Lee SJ. Guided Immediate Implant Placement with Wound Closure by Computer-Aided Design/Computer-Assisted Manufacture Sealing Socket Abutment: Case Report – Int J Oral Maxillofac Implants. 2017 Mar/Apr;32(2):e63-e67. doi: 10.11607/jomi.4770
3. Finelle G, Sanz Martin I, Knafo B, Figué M, Popelut A. Digitalized CAD-CAM protocol for the fabrication of customized Sealing socket healing abutments (SSA) in immediate implants in molar sites. A Case series. Int J Comput Dent. 2019;22(2):187-204.
4. Finelle G; Knafo B, Figué M, Popelut A, Sanz Martin I. Sealing socket abutments (SSA) in molar immediate implants with a digitalized CAD-CAM protocol. Soft tissue contour changes and radiographic outcomes after 2 years. (IJPRD) ACCEPTED FOR PUBLICATION
5. Chu SJ, Salama MA, Salama H, Garber DA, Saito H, Sarnachiaro GO, Tarnow DP. The dual-zone therapeutic concept of managing immediate implant placement and provisional restoration in anterior extraction sockets. Compend Contin Educ Dent. 2012 Jul-Aug;33(7):524-32, 534