This case series report documents 5 successful cases of immediate implant placements into fresh extraction sockets in the esthetic zone, subsequently restored with favourable outcomes. The case selection, treatment planning, surgical protocol, restorative outcomes are presented and discussed.
The original implant surgical protocol proposed by Branemark et al1 involves open flap access, stepwise osteotomy of the bony ridge, and implant placement followed by good primary closure.
If the patient presents with a failing tooth, extraction must be performed and the socket allowed to heal for 3 to 6 months before replacement with a dental implant can be considered. After complete socket healing has taken place, bony ridge and soft tissue deficiencies that render the site unsuitable for implant placement need to be addressed first. A variety of hard and soft tissue ridge augmentations may be used, but overall treatment time is prolonged.
Though a lengthy procedure, this had been a reliable protocol adopted by surgeons worldwide due to its predictable and systematic nature, allowing complications that may arise from each step to be dealt with appropriately.1
However, with technologic advances and new surgical innovations, various radical modifications to this original protocol had been introduced that showed promising and predictable outcomes. One such treatment protocol is the placement of implants into fresh extraction sockets, otherwise commonly known as immediate implant placement.2
Immediate implant placement may be defined as implant placement immediately following tooth extraction and as part of the same surgical procedure,2 or as implant placement immediately following extraction of a tooth which must be combined in most patients with a bone-grafting technique to eliminate peri-implant bone defects.3
This technique has a number of proposed advantages such as preservation of bone and soft tissue, decreased total treatment time, reduced number of surgical procedures, reduced overall cost, and better patient acceptance.3,4
However, discrepancies between the size of the implant and sockets, poorly vascularized infected bone at the implant site, difficulty controlling 3-dimensional implant position, and primary stability are some of the surgical challenges that operators face.4 Therefore, this unique procedure is generally not recommended for the novice surgeon.
This article presents a case series of immediate dental implant placements into fresh extraction sockets in the esthetic zone by a single oral and maxillofacial surgeon. The case selection, treatment planning, surgical protocol, and restorative outcomes are presented and discussed.
Materials and Methods
This series reports 5 consecutive cases out of 8 seen and treated by a single oral and maxillofacial surgeon from the Department of Oral and Maxillofacial Surgery, National Dental Centre, Singapore between December 2008 and April 2011 (Table 1).
The following inclusion criteria were employed in patient selection for this case series:
Noncontributory medical history;
Moderate to low smile line;
Teeth to be extracted: single tooth cases in the esthetic zone defined as upper central incisors, lateral incisors, and canines; free of acute infection, and the presence of adequate apical bone for implant stability;
Socket: intact labial wall; presence of no more than 4-mm distance between the labial alveolar crest and free gingival margin after tooth extraction, a clean healthy socket indicated by absence of granulation tissue, and presence of fresh bleeding post extraction;
Favorable gingival biotype defined as moderate to thick gingival character;
Surgical protocol: single stage flapless implant placements following extractions; and
Cases that had final crowns delivered and subsequently followed up.
In the process of selecting the cases for this report, the exclusion criteria were the total or partial lack of the above inclusion criteria.
Three cases were excluded. One patient underwent a 2-staged open flap procedure for implant placement of a left maxillary central incisor, being part of a restorative plan for a 4-implant retained maxillary overdenture. Another patient was lost to follow-up after surgery. The third patient was excluded because of an implant placed immediately into the osteotomy site of an implant that had to be explanted due to malposition. This case was also a 2-stage procedure.
Clinical evaluation and patient preparation
Standard clinical assessment was carried out for all 5 patients.
Significant past medical history, general health, and smoking habits were documented. No patients presented with significant medical or systemic issues that could compromise dental implant success.
Patient 4 had been a smoker for at least 10 years. The patient was advised to stop smoking for at least 2 weeks before the surgery and at least 6 weeks after the surgery.
Clinical assessment included extraoral examination followed by intraoral examination. This was carried out jointly with a prosthodontist, and the case was evaluated based on the inclusion and exclusion criteria previously stated.
Preoperative radiographic assessment
Except for patient 5, who had only periapical radiographic assessment of the tooth to be extracted, all other patients in this series underwent both periapical radiographic investigations and cone beam computerized tomography (CBCT). The CBCT scans were done to assess the thickness of the labial plate.
The implants used in this case series are described in Table 2.
Patients 1, 2, 3, and 4 received NobelReplace Tapered Groovy implants with oxidized TiUnite surfaces (Nobel Biocare, Göteborg, Sweden).
Patient 5 received a BIOMET 3i implant with dual acid-etched, nanometer scale discrete crystalline deposited surface (NanoTite, BIOMET 3i, Palm Beach Gardens, Fla).
Surgical Technique and Outcome
The surgical procedures were all carried out under local anesthesia in sterile surgical conditions. All patients received 1.0 g of amoxicillin orally 1 hour preoperatively.
The teeth were extracted with minimal trauma by first performing a peri-incision of the free gingival attachment, which was then freed off the cervical margins. The teeth were then luxated and mobilized with a periotome before forceps delivery.
After the teeth were extracted, the sockets were thoroughly curetted and cleansed with copious saline irrigation to remove all remnants of periodontal tissue and debris. The surgeon ensured fresh bleeding from the socket walls was present before proceeding with the implant site preparations.
The site preparations were then carried out according to the implant system protocol. A surgical guide was used throughout to ensure a prosthodontically favorable placement of the implant in 3 dimensions along with copious irrigation. The drilling procedures were initiated on the palatal socket walls and apical to the socket depth to avoid damage to the labial plate as well as for apical bony engagement to achieve primary stability. A final lavage of the osteotomies was carried out to ensure a debris-free site before inserting the implant.
The implants were inserted first with a handpiece at the recommended torque, and final seating was completed manually. All implants demonstrated good primary stability. Titanium healing abutments were then placed as a 1-stage protocol. The labial peri-implant socket gaps were then grafted accordingly, and a resorbable collagen dressing secured over the socket-implant site via figure-of-eight sutures.
Immediate postoperative radiographs were done to confirm complete seating of the healing abutments as well as a baseline record. All patients received a 5-day regimen of postoperative oral amoxicillin, 500 mg every 8 hours, and 0.2% chlorhexidine oral rinse upon discharge.
The patients were followed up about 1 week after surgery, thereafter at 1 month, and referred for prosthodontic restoration after 3 to 6 months of healing.
All 5 extraction sockets had intact labial walls after extraction. This was confirmed by using a periodontal probe to check for labial wall integrity.
Following placements of the implants, primary stability of all cases was good. The labial peri-implant socket gaps of patients 1, 3, and 4 measured about 2 mm and were grafted with Bioactive Glass alloplastic bone substitutes. Patients 2 and 5 had labial peri-implant socket gaps of slightly more than 2 mm and were grafted with alloplastic bone substitutes and autogenous bone, respectively.
All 5 cases had good soft tissue architecture preservation at 1 week after surgery with minimal edema, and there were no complaints of pain or discomfort during the early postoperative healing period.
All implants achieved successful osseointegration after a healing period of 3 to 6 months. The residual peri-implant socket spaces were found to be well-healed, exhibiting no implant thread exposures at the end of the healing phase.
The soft tissue architecture remained stable with preservation of adequate attached gingiva throughout the healing period of the implants as well as after final prostheses delivery, contributing to esthetically pleasing and biologically sound results.
All 5 patients were very pleased with the esthetic outcomes of their treatment (Figure 6).
Immediate placements of dental implants into fresh extraction sockets present to the surgeon unique challenges not encountered in conventional implant placements.5
Some of these challenges identified include size of the extraction socket being larger than the implant dimensions; infected, poorly vascularized, necrotic bone at the implant site; difficulty in controlling implant position and angulation; bony dehiscence/perforation of the bony housing during site preparation; incomplete seating of cover screws and/or healing abutments; and difficulty in achieving primary stability.6,77
These challenges arise fundamentally from the surgical objective itself, which is to insert an implant, essentially a symmetrical object, into an extraction socket that is variable in 3-dimensional morphology. Therefore, the surgeon performing this procedure should possess adequate experience with conventional methods before taking on such cases.
There is a paucity of well-controlled, randomized clinical trials documenting immediate placements of dental implants into fresh extraction sockets. A comprehensive review by Chen et al4 in 2004 revealed that most reports were nonrandomized with respect to the timing of implant placement and bone augmentation used. Only 4 longitudinal studies with mean follow-up 3 to 5 years were reported, and the rest consisted of case reports with observation periods of 12 months or more.
There seems to be a lack of a well-defined protocol in terms of patient selection, investigations, and surgical technique available in the literature.
However, absolute contraindications to immediate implant placements have been agreed by many, such as the presence of periodontal disease, acute/subacute periodontal or periapical infections, and unfavorable anatomy.8–10
Presence of the above contraindications would automatically exclude a case from immediate implant placement. In this report, all cases had none of the above contraindications in the preoperative assessment.
All patients in this case series underwent detailed surgical and prosthodontic evaluation prior to surgery. The most important issue addressed at this stage was the bone volume adequacy for implant placement. Except for patient 5, all bony assessments were done with the aid of the CBCT, and the implant positioning was planned to ensure that there is a minimum of 5 mm apical bone dimension beyond the root apex of the tooth to be extracted. The CBCT was not performed for patient 5 because the patient had cost concerns regarding this investigation. After assessing the periapical radiograph of patient 5 as well as assessing the patient clinically, the author felt comfortable to proceed with the surgery without a CBCT and agreed to the patient's request.
The surgical protocol was standardized for all 5 cases. All 5 teeth were extracted with minimal trauma by first luxating them with a periotome. This was a useful technique, resulting in preservation of intact labial walls of all 5 sockets, which is required for eventual healing and soft tissue framing.11
There is no consensus available in the literature; however, from the author's anecdotal experience, there should be no more than 4-mm distance measured from the free gingival margin to the crest of the labial socket wall if left intact. An increased distance of more than 4 mm would risk soft tissue apical migration and hence metal show in the eventual restorative outcome. This important factor was checked before proceeding with the implant site preparation.
In all cases, there were no bony fenestrations after osteotomy. This was achieved because the osteotomies were carried out engaging the palatal socket walls and beyond the apex. The author felt that this was the most challenging phase of the surgery as the relative increased thickness and density of the palatal bone tends to provide resistance to drilling, therefore risking labial transporting of the drills and perforating the labial socket wall. Furthermore, the osteotomies had to be carried out in strict accordance with the planned implant positions as dictated by the surgical guide in ensuring a restorable outcome. Hence, the dual surgical objective of labial socket wall preservation and proper 3-dimensional site preparation makes this the key phase of the procedure—failure of either one or both would severely compromise final outcomes.
Once this key phase is over, the implant placements would be relatively straightforward. All 5 implants demonstrated good primary stability. The residual peri-implant socket distances for all implants were found to be no more than 2 mm. Although reported by Chen et al4 that the consensus was gaps of 2 mm or less required no grafting, the author proceeded to graft the defects for all cases as a standard procedure.
There are many options of bone substitutes available on the market and well-documented literature in terms of their success and clinical efficacy. Commonly used bone substitutes include particulated allografts, xenografts, and alloplasts. Recently, alloplastic materials of injectable form such as calcium phosphate cements have been shown, in experimental research, to improve the stability of implants following placement.12,13 The choice of graft material was made predominantly by its ready availability. In patient 5, autogenous bone was used because she had to undergo simultaneous removal of impacted mandibular wisdom teeth. The bone was harvested from the ramus after removal of the wisdom teeth and particulated for grafting into the residual peri-implant socket. Patients 1 to 4 had Bioactive Glass due to its relative low cost.
A single stage protocol was adopted in this case series. All healing abutments were verified to be well seated by immediate postsurgical periapical radiographs. The author would wish to mention that the choice of healing abutments is important at this stage because healing abutments with excessive cervical flare or customized anatomical abutments usually present with incomplete seating as they would be interfered with by the crestal socket bone. All healing abutments chosen in this case series were without flare and of adequate height to emerge slightly above the socket (Table 2). This prevents soft tissue overgrowing the site.
There is also lack of data regarding the requirement of complete soft tissue coverage in single stage immediate implant placement. A report of 9 patients by Schwartz-Arad and Chaushu14 indicated that implants can be successful without sealing the socket orifice with a resorbable membrane.
In the protocol used by the author in this study, the author used a resorbable collagen sponge dressing over the socket, including the healing abutment and graft material, primarily as a blood clot stabilizer.
All 5 patients were very pleased with the esthetic outcomes of their treatment (Figure 6). The author would like to point out that, as evident in Figure 6, patients 3, 4, and 5 possess increased gingival show on full animated smile. This feature would be considered a risk factor for immediate implant placements, especially in the esthetic zone. The author had warned these patients about the risk of metal show compromising esthetics in case of labial bone resorption and obtained their informed consent before proceeding. Such patients should be treated with caution, and the author would not recommend taking on such cases for novice practitioners.
Immediate implant placements into fresh extraction sockets should not be attempted by the novice surgeon, especially for cases in the esthetic zone. However, with good case selection following detailed clinical and radiographic examination, adequate clinical experience and judgment, this protocol, which is well received by patients, can lead to successful outcomes both esthetically and functionally.