1. Immediate Socket Implants Enhanced with L-PRF
Robert A. Horowitz, DDS, Scarsdale and NY, NY
Abstract
Methods and Materials
Results
Bone resorption begins the moment a tooth is extracted through loss of the bundle bone crestally and parts of the buccal and lingual plates from their outer surfaces. With immediate socket implantation, there are fewer surgical visits, less insult to the hard and soft tissues and an ability to maintain the patient’s esthetic profile. A question remaining is how to deal with "the gap". A recent publication demonstrated histologic osseointegration with only a blood clot there. Patients may get food, bacteria or other materials in the gap which could interfere with successful osseointegration. One way to avert this issue is by placing leukocyte rich platelet rich fibrin (L-PRF) in or over the gap. This presentation will document a number of cases where that technique was employed with successful clinical and aesthetic results.
In the series of case reports included in this study there are a total of 14 immediate socket implants with 6 prosthetically loaded that day. All implants have since been restored with excellent functional results, healthy keratinized tissue and minimal postoperative inflammation. The L-PRF is simple to process as it is formed from blood taken from the patient in an easy manner with only one spin in the centrifuge. There are no additives nor heat treatment required. The slow ciccatrization process by which the L-PRF barriers and plugs are produced is part of the reason that there is a 10 day release of VEGF, TGF-B and other growth factors in the site. Clinically this is demonstrated by fast vital bone formation in sockets, preservation of alveolar ridge width and preservation and enhancement of keratinized tissue. As a majority of the bone formed is vital, the results hold up over time.
At the time of atraumatic extraction, an osteotomy is prepared to enable ideal insertion of an endosseous dental implant. After placing the implant in the bone, there is invariably a gap between the implant and the buccal plate of bone, in some instances there may be spaces around other parts of the implant. Placement of a particulate graft material in this space may alter osseointegration by delaying the formation and attachment of a blood clot in these areas. Incorporation of an L-PRF clot will benefit this process through stimulation of angiogenesis and osteogenesis. Depending on the stability of the implant, the implant can be transitionally loaded. The L-PRF membrane or plug can be placed on top of the blood clot in the gap filling the space between the abutment and transitional restoration and the soft tissues. This will seal the area and protect the fibrin clot which is attached to the implant surface
This patient presented for removal of a hopeless mandibular first molar tooth. As he was recently past hip replacement surgery the orthopedist wanted only minimal treatment performed. In preparation for a delayed implant placement the socket was fully degranulated with diamond burs and then filled with PRF plugs. NO flap elevattion was performed. The final photo and radiograph show complete keratinization of the site and fill with radio-opaque, trabeculated bone at only 5 weeks postop. This makes L-PRF the ideal material to fill gaps in immediate socket implants.
Introduction
For over 25 years endosseous dental implants have been inserted into fresh extraction sockets with varying degrees of clinical success. Based on the work of Scipioni (1994, 1997, 1999) it has been documented that in sites where no graft material was placed adjacent to this gap led to both clinical success and histologic osseointegration. When primary closure was obtained over this gap, migration of connective tissue cells into that zone impeded bone to implant contact. For this reason, clinicians have investigated the insertion of bone grafts in and/or placement of barriers over the treated areas. While immediate socket implants successfully retain prostheses for long periods of time, there are multiple studies documenting site collapse using this technique. Additionally, there is minimal human documentation of osseointegration in the gap between the implant surface and bone. When autogenous bone was placed in this area (Schropp 2003), careful analysis at the time of reentry documented residual infrabony pockets around the implant surface. Other materials placed in this gap have been shown to be non-resorbable in humans (Carmagnola 2003, Tal 2000 and 2001). For these reasons a study was undertaken to document the feasibility of using L-PRF plugs in and over the gaps present at the time of immediate socket implant placement as the sole filler and barrier. .
This 87 year old diabetic patient presented for removal of a fractured maxillary premolar tooth. To speed treatment for him it was decided to perform implant placement and sinus augmentation at the same time. Atraumatic extraction and thorough debridement were followed by the use of specific lateral cutting buts to decrease chance of membrane perforation in the osteotome sinus augmentation procedure in both teeth. The first material used to infracture the sinus floor and elevate the membrane was L-PRF.
This 81 year old famale patient presented for removal of a hopeless maxillary first molar tooth between rounds of chemotherapy. Sectioning and atraumatic extraction of the tooth revealed some bone in the trifurcation area. To enable placement of a longer, wider implant in the site osteotomes were used for both site preparation and sinus elevation. The initial material for sinus infracture was L-PRF. Grafting in the sinus and roots was performed with mineralized cancellous allograft hydrated with L-PRF amd mixed with biphasic calcium sulfate. The final images show advanced soft tissue healing and graft maturation leading to prosthetic loading in 5 months.
Conclusions
Membrane elevation was competed with mineralized allograft hydrated in L-PRF and mixed with biphasic calcium sulfate. The implants that were placed has a bioactive calcium phosphate impregnated surface, a blossom cutting thread and excellent stability even in minimal bone.
Advanced healing can be seen in the progression from placement to 5 months.
Histologically, studies will have to be performed to determine the benefit to adding this relatively simple step into the protocol for placement of immediate socket dental implants. The concerns for ideal outcome include hard tissue preservation, soft tissue preservation or enhancement and bone-to-implant contact in the gap. From this short term study, employing an L-PRF clot in or over "the gap" at the time of immediate socket implant placement leads to high clinical and aesthetic success. The alveolar ridge width is preserved over 85%, keratinized tissue is maintained in most cases and it is enhanced in others. From the patient perspective, the most important points are that all of the implants placed and loaded in this study have been successful as far as both osseointegration and aesthetics are concerned. Pairing this potent autologous growth factor with a dental implant designed and treated to maximize osseointegration through biologic processes adds to the successful results.
This 85 year old female smoker presented requiring extraction of a mandibular left first molar tooth. As the roots were angled there was a very good opportunity to place an implant at the same time as the extraction. Piezosurgery was used to assist in both the extraction and osteotomy preparation. The gap around the nano-calcium phosphate surface coated implant was filled only with L-PRF and covered with an L-PRF barrier. The final radiograph and clinical photograph show the advanced healing in only 5 weeks. The implant is buried and bone filled the root sockets.