Today, it is generally accepted amongst clinicians that endosseous dental implants have become the standard of care when listing treatment options for restoring an edentulous space. This was not the case as early as 20 years ago! Over the last 4 decades translational science and clinical research have broadened our knowledge around the processes of osseointegration while deepening our understanding of bone physiology not only from a cellular level but also from the perspectives of biomechanics. Implant dentistry has come to transcends the age-old concept of multidisciplinary treatment planning. As clinicians seek perfection in the delivery of care for providing the best possible treatment for their patients, clinicians would be remiss to not acknowledge that implant dentistry is a prosthetically driven concept, executed in the most fluid artistic realms of surgery, based on scientific foundations.
As more and more clinicians pick up arms to enter this infamous battle against edentulism, the battlefield is becoming more heterogenous than ever before. There are more dentist getting involved in implant dentistry right out of dental school. What was once accepted to be a discipline only for the experienced clinician, is now being practiced by clinicians with vastly different levels of experience.
Consequently, more than ever before, it is crucial for the profession to try to have a common classification system to allow clinicians with varying levels of experience and skillset to determine the level of complexity of a case prior to entering the surgical and prosthetic battlefield of implant dentistry.
The International Team of Implantology (ITI), introduced the SAC classification1 which is fairly simple and easy to apply to everyday practice. It is a comprehensive process that walks the clinician through a multitude of questions online through their website, where at the conclusion of the questionnaire it provides a patient report card describing the patient’s level of complexity; Straightforward, Advanced, & Complex. This article will be discussing a case report of a patient whose SAC classification is ranked complex.
The edentulous posterior maxilla has challenged clinicians for many decades. Not only does it have a unique anatomy compared to the rest of the mouth it also is in proximity to the maxillary sinus floor and the venous plexus nearby. Furthermore, it has a soft tissue envelope unlike anywhere else in the oral cavity where half of the soft tissue is completely attached (palatal tissue) while the other half is mobile (buccal tissue). All of the above mentioned are significant factors before we even discuss the different bone density found in this region. Thus, justifying the challenges not seen elsewhere in the oral cavity. As our understanding of bone physiology has deepened over the years, the importance of primary stability for successful osseointegration of dental implants has become more evident than ever before.2
Immediate implant placement in the site of a single rooted tooth comes with certain complexity factors from the moment the tooth is being extracted atraumatically to the process of creating the ideal osteotomy with the perfect angulation and spatial orientation. However, the challenges exponentially increase when faced with the site of a multirooted tooth surrounded by an environment with low bone density and in most cases with very close proximity to the sinus floor or inferior alveolar nerve canal.
The traditional approach has been to stage the treatment into 3 phases; 1- an extraction phase, 2- a site development phase which typically would include a sinus lift/augmentation procedure and, 3- eventually a dental implant placement phase. Sometimes the latter would be followed by a fourth surgical phase which would be a soft tissue augmentation procedure prior to sending the patient for the restorative phase.3
So overall the patient could be exposed to four separate surgical appointments with four separate healing and recovery periods. In the world that we live in today where time has never been so valuable, it is very understandable when patients demand and expect more from their dentist to help them recuperate as much time as possible albeit maintaining a similar success rate in therapy. Patients don’t want to take time off work, time away from family, they don’t want to have downtime following surgery, they don’t want to have limitations, let alone going through all of the above for four times! As such there is a very strong push and demand from our patients expecting us to be able to combine as many therapies as possible when the possibility presents itself.
In the recent past it is not uncommon for most experienced clinicians to combine an extraction appointment with a site development procedure where a tooth can be removed, and an immediate bone augmentation procedure can be executed to develop the adequate volume of bone horizontally and vertically. Typically, the difficulty with these procedures in the posterior maxilla have been the limitation created by the attached palatal soft tissue when trying to achieve primary closure to improve the success rate and the predictability of the regenerative procedure. Regenerative procedures such as ridge augmentation with contour grafting for implant site development as well as sinus augmentation procedures in the posterior maxilla, typically require primary soft tissue closure, essential for a successful, reliable and predictable outcome.4 As described in the literature by many authors, there are soft tissue manipulation techniques which allow for the release of the internal tensions of the flap through periosteal scoring and coronal positioning of the tissue in order to obtain a passive primary closure.
There are multiple factors to be considered when looking at an immediate implant placement in the molar region. Firstly, the most important is to preserve as much of the fresh extraction socket anatomy including an intact septum bone and socket walls with nice thick gingival phenotype (in an ideal situation). Most importantly sufficient bone apical to the socket coronal to the sinus floor in the maxilla, and coronal to the inferior alveolar nerve canal, in the mandible.
It is important to recognize that immediate implant stability should be sought from the apical third of the implant whenever possible and binding at the coronal 3rd should be avoided as much as practical. Otherwise, significant crestal bone remodeling could ensue.
In the posterior region as one can imagine this leads to a limitation. In the mandible Lin et al.5 demonstrated that a 6 mm distance between the root apex to the mandibular canal is considered safe. However, this distance decreases from about 7 millimeters in the first molar region to about 4 millimeters in the second molar region. Thus, accounting for the majority of mandibular nerve complications occurring in the mandibular second molar extraction site (about 70%) compared to the mandibular first molar site (about 35%). Regarding the lingual concavity for the mandibular molars, the mandibular second molar again is at a higher rate at around 62% compared to the mandibular first molar about 57%.6
Regarding the maxilla, the combination of limited vertical quantity of bone apical to the extraction socket and coronal to the sinus floor along with low bone quality leads to several complex surgical challenges when it comes to implant stability for the maxillary molar extraction socket. Anchoring down the implant into the sinus floor in combination with a sinus floor elevation may optimize implant primary stability. A 5 millimeter distance has been reported in the literature to be necessary to allow for ideal immediate implant stabilization into the sinus floor.7
Atraumatic extraction is the most crucial step in the ability to be able to perform an immediate implant placement in the molar region. Care must be taken to preserve the septal bone and to minimize any disruption to the surrounding tissues. Ragucci et al.6 in a systematic meta-analysis reported a success rate of over 93% for immediate implant placed in the molar site where marginal bone remodeling was about 1 millimeter after one year.
Implant position and size is a significant factor when it comes to immediate implant placement in the molar socket. Ideally the implant should be placed about 1 to 2 millimeters below the buccal crestal bone.8 This leads to an increased bone implant contact and less long term crestal bone remodeling and it provides better running distance to obtain ideal crown contours gingiva- occlusally.
Grafting the gap distance surrounding the implant has been demonstrated to increase both survival and success rate, especially when it is greater than 2mm.9 Classic wide diameter implant (about 5 millimeters in diameter) is the ideal size implant for an immediate implant placement in the molar socket, as smaller and larger diameter implants appear to lead to further complications and or higher failure rates.10
As Osseodensification protocols are dependent upon intact fresh extraction socket integrity, most commonly, they would begin in the furcation area of a multi rooted tooth. Nevertheless, at the end of the day, the ideal position must always be determined based on the restorative guidance. The drilling protocol can be found on the Versah.com website depending on the implant system utilized. Generally speaking, a pilot drill rotating in a clockwise mode will initiate the osteotomy. Subsequently densifying burs rotating in a counter clockwise direction under copious irrigation allow for the expansion of the osteotomy to receive the ideal sized implant being utilized. Maintaining the bone bulk to allow for preservation of bone plasticity is the cornerstone of this process. Bone grafting of the gap distance in this scenario is performed prior to the implant placement by utilizing the bone graft propel feature of the Versah drilling protocol.
In today’s article the authors will be sharing a case report about a patient undergoing all four of the previously described phases of the surgical stage of therapy in a single appointment. Extraction of 3 maxillary molars with simultaneous horizontal and vertical ridge augmentation and simultaneous sinus augmentation with immediate implant placement in the first and second maxillary molar region along with a simultaneous soft tissue grafting while utilizing the Versah Osseodensification and Lift protocols.
A 60-year-old Caucasian female is referred by her dentist for the extraction of 16, 17, 18 and placement of implants 16 and 17 for an implant supported restoration with two screw retained splinted crowns. The patient reports severe dental anxiety otherwise healthy with non-contributing medical history. Upon further evaluation of her medical and dental history along with examining her intra and extraoral tissues, it becomes evident that the patient had a previous history of pocket reduction surgery in the region about 5-6 years prior. She presented a non-harmonious occlusal plain with large exposed embrasures between the molars. (Fig. 1) Severe horizontal bone loss was evident radiographically as well. (Fig. 1B) Extremely close proximity of the maxillary sinus floor to the apices of molars. The teeth were previously restored with composite restorations and porcelain fused to metal crown which was exhibiting radiographic evidence of recurrent caries. Tooth 14 had been removed previously for orthodontic reasons as a child. Tooth 15 was in a palatal position relative to the adjacent teeth. (Fig. 2) Tooth 16 presented with a 10mm probing depth on the disto-buccal with a class II furcation on the distal. Tooth 16 was deemed not restorable. Probing depths around 17 and 18 ranged between 7mm to 8mm, with a poor periodontal prognosis. Although 15 had bone loss it was agreed with the patient to attempt to save the tooth and maintain it, especially since there was no mobility on the single rooted tooth. The game plan was to remove 16, 17, 18 utilizing the Piezosurgery atraumatic extraction protocol with a simultaneous transcrestal sinus augmentation via Versah Lift and immediate implant placement utilizing the Versah Osseodensification drilling protocol with simultaneous osseous ridge augmentation through guided bone regeneration (GBR) and concomitant vascular interpositional pedicle connective tissue graft (VIPCTG) with a planned delayed phase 2 uncovery. Patient consented to the treatment and the details are described below.
Cone Beam Computer Tomography was obtained and evaluated prior to the procedure. The osteomeatal complex was observed to be patent. A vacu-shell style surgical guide was fabricated in preparation for the surgical intervention. Patient had decided she did not want to have a pre- implant orthodontics alignment done to improve her curve of Spee and Wilson and she did not want to align her teeth nor to improve the position of 15. She was informed and aware of the limitations of implant prosthetics adjacent to a palatally positioned 15. In light of the above, the restorative plan was to recreate her existing occlusion as such the surgical guide was a replica of her existing occlusion.
The Surgical Procedure
To address the patient’s dental anxiety, the procedure was performed uneventfully under intravenous (IV) sedation utilizing combination of Versed and Fentanyl. Bupivacaine was utilized for local anesthesia to obtain profound and long-lasting local anesthesia.
Sulcular incisions were made with full thickness flap elevation to access the underlying bone. A vertical release incision was placed between 13/15 to improve surgical access and flap mobility. Clean flap elevation was obtained utilizing the large molt elevator while performing a half circle scooping motion to maintain bone contact at all times in order to avoid any tissue tear.
Once the flaps were elevated and reflected the molars were de-coronated utilizing a 702 surgical long shank bur and then sectioned through their furcation to divide them into their individual roots. At this point the Piezosurgery extraction tips were utilized to execute an atraumatic extraction of each individual root in an attempt to maintain all the surrounding bone, especially the buccal and palatal plates and more importantly the intra-radicular septum bone. This is a critical step as any loss of septum bone in this step could render the immediate implant placement planned for the surgery null and void. The sockets are then well debrided utilizing a reverse scoop method to enucleate any residual periapical cysts or granulation tissues. The goal is to obtain a nice clean bony socket void of any soft tissue. (Fig. 3) Care must be taken to avoid an accidental perforation of the sinus floor in areas of the socket which have close proximity to the maxillary sinus floor. Typically, this is visualized by a dark purple/grey hue at the apex of the socket.
At this point the surgical guide is utilized to commence osteotomy preparations based on the restorative plan. (Figs. 4 & 5) As these sites were planned to be prepared via Versah Osseodensification, the Versah bur kit was utilized as per the Versah Lift protocol in combination with the Versah Osseodensification protocol. Kindly note the combining of the 2 different protocols is considered an advance and complex procedure so it is not advised for the novice clinician to attempt this without adequate formal training and good case selection. The advantage of combining the 2 protocols affords the clinician and the patient two major surgical advantageous; #1 transcrestal sinus augmentation, and #2 increased implant stability through increased bone to implant contact (BIC).
Strauman SLActive Roxolid Tapered Effect Tissue Level implants were selected as the implant of choice for many reasons. (Fig. 6) As for any immediate implant case a tapered implant is always preferred to a straight implant. Considering the posterior location of these implants, the tissue level implant has multiple advantageous such as distancing the abutment-implant interface and hence leading to less crestal bone remodeling since the biologic width is protected. The broader nature of the connection affords a better distribution of forces along the implant platform as the crown sits directly on the implant shoulder vs the abutment only, as is the case with bone level implants. There are also reports in the literature that the tissue level implants appear to perform better against peri-implantitis tissue breakdown, again thought to be due to the one-piece nature of the implant.11,12
Mineralized Freeze-dried cortico-cancellous allograft from Citagenix was hydrated in the PRF concentrate for about 20 minutes. The bone graft was then packed into the surgical site (Fig. 9) and it was then covered by a NeoMem resorbable collagen membrane from Citagenix. (Fig. 10) The membrane was trimmed into position and then placed over the surgical site and bone graft. The collagen membrane was then covered by the PRF membrane. (Fig. 11)
The surgical flaps have already been mobilized through periosteal scoring. (Fig. 8) However, to better protect the surgical site against possible wound opening and to simultaneously improve the soft tissue profile around the implants, a VIPCTG is harvested from the adjacent palatal tissues and flipped over the top of the crest to help with flap closure as well as to improve soft tissue phenotype around the implants. (Fig. 7)
Passive primary closure is obtained with PTFE sutures from Citagenix utilizing a combination of horizontal mattress and simple interrupted suture configuration. (Fig. 12)
Both implants are placed at high insertion torque of 50ncm. This is achieved purely as a result of the Versah osseodensification drilling protocol. The implants are both 4.8x10mm Straumann Roxolid SLActive TE Tissue Level buried with a cover screw. Successful Versah Lift is confirmed via the presence of the radiographic “dome”. (Fig. 12B)
Patient was prescribed Amoxicillin 500mg tid commencing the day prior to surgery. She was given Peridex bid also starting the day prior to surgery. Dexamethasone and ibuprofen to control both pain and swelling were prescribed as well. She had also started Neil Med sinus rinse bid for 2 weeks prior to her sinus lift surgery.
Patient was seen for the following few weeks for post-op care, and each appointment was uneventful and routine.
Phase II (uncovery surgery)
Five months afterwards, the patient is seen for simple re-entry phase II uncovery surgery for both implants. (Fig. 13) The previous VIP connective tissue graft afforded the patient with a better implant emergence profile to protect against plaque stagnation areas around the implant crowns. A palatially biased crestal incision allows for the repositioning of the newly obtained thicker soft tissue to the buccal of the implants. (Figs. 14, 15 & 16)
Patient is greenlighted to go see the referring restorative dentist for screw retained crowns.
5 year Follow Up
The radiograph and intraoral pictures below are depicting great marginal bone stability and nice long lasting osseointegration for immediate molar implants with simultaneous extraction, bone graft, sinus lift and concomitant VIPCTG. (Figs. 17, 17B & 17C)
Immediate implant placement in the molar region is a well-documented and predictable procedure when cases are selected properly, and the technic is executed meticulously. The major advantage for the patient is not just the saving in time but most importantly the reduction of surgical interventions and the associated recovery limitations for each intervention. Less number of procedures, which translated into reduced number of times the tissues are going to be manipulated which leads to less scar tissue and less tissue shrinkage.
As the old saying goes; “time is money” and for many patients this holds true, for time taken away from their work or time taken away from their family.
Ultimately, if the tables were turned and we (the dentist) were placed in the shoes of the patient and were faced with making a similar decision regarding ourselves, and we were offered a medical/dental procedure that combined multiple therapies with less number of interventions and less number of preparatory and recovery periods which only required us to take prescription medications only once rather than multiple times, it would be fair to say “we” the patient would select the single intervention method every time as well.
The authors hope this case report has shed some light on the predictability and reliability and reproducibility of the immediate implant placement in the molar site and in doing so, perhaps this article has stimulated a conversation on the possibilities that exist for both our patients, as well as our fellow colleagues.
Oral Health welcomes this original article.
Submitted for review of Publication: Journal of Oral Health (November 2022 edition)
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About the Author
Omid Kiarash is a board certified Periodontist. He is the immediate Past President of the Canadian Academy of Periodontology. He is the former Director, Department of Periodontics, Faculty of Dentistry at McGill University. Dr. Kiarash maintains his private practice in Montreal. He is the founder of ZeebaEducation.com, with its mission to provide excellence in continuing dental education for dentists.
Sara Behmanesh is a board certified Periodontist. She is the president of the Montreal Dental Club and an executive member of Federation of Dental Societies of Greater Montreal. She is a former clinical instructor, faculty lecturer and course director in the Department of Periodontics, Faculty of Dentistry at McGill University.