Achieving Predictable Facial Bone Reconstruction at Immediate Implant Placement Utilizing the Facial Allograft Shield Technique

Abstract: Resorption following tooth loss often presents challenges to both functional and esthetic outcomes of dental implant treatment for lost dentition, especially in the esthetic zone. Inadequate bone volume at the implant site is common, and bone augmentation is often required. While autogenous bone is usually preferred, it is not applicable in every case and can necessitate multiple surgeries and extended healing times for patients. In such situations an alternate protocol, the facial allograft shield technique using an allogeneic laminar bone membrane, may offer a minimally invasive, effective alternative for managing type II socket defects in the esthetic zone. This approach can potentially expand the pool of candidates eligible for immediate implant protocols. This case series introduces this technique for reconstructing severely compromised or absent facial cortical plates at the time of immediate implant placement.

Dental implant restoration remains a highly predictable modality for re-establishing both form and function following partial or complete edentulism.¹ After tooth loss, however, the alveolar process undergoes a predictable resorptive pattern, often resulting in dimensional changes that can compromise both functional and esthetic outcomes if the bone resorption is not properly addressed prior to or during implant placement.2 These dimensional osseous alterations may be further compounded by chronic periodontal or periapical infections, traumatic injury, or other pathologic conditions affecting the alveolar ridge.² Frequently, loss of a tooth in the esthetic zone is the result of periodontal changes that lead to the need for extraction of the tooth. Additionally, related to the “triangle of bone,” dehiscence of the facial aspect of the ridge overlying the tooth’s root can compromise the ridge width, potentially hampering replacement with an implant.³ Despite significant advances in implantology, including the development of narrow and short implant designs and the introduction of novel restorative materials, the challenge of re-establishing lost bone volume remains a central concern.⁴ Long-term success, particularly in the esthetic zone, requires maintaining adequate facial bone thickness over the implant. Clinical consensus suggests that a facial cortex thickness of at least approximately 1 mm at the time of immediate implant placement (IIP) is necessary to provide stable soft-tissue support, reduce the risk of facial bone resorption (dehiscence), and minimize the potential for peri-implantitis or early implant failure.^5,6 Unfortunately, many clinical sites fail to meet these requirements, necessitating augmentation procedures to achieve both optimal biomechanical stability and esthetics.^5,6

It is estimated that roughly 50% of all implant procedures require bone grafting at the time of implant placement.¹ This reinforces the central role of augmentation in contemporary implant surgery, particularly in relation to patient expectations regarding esthetics, longevity, and minimal invasiveness.⁷ Selecting the most appropriate grafting material and technique requires consideration of the defect’s morphology and volume, host bone quality, and periodontal and peri-implant soft-tissue health.⁸

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Autogenous bone remains the gold standard for bone augmentation because of its unique trifecta of osteogenic, osteoinductive, and osteoconductive properties.⁹ Intraoral donor sites such as the maxillary tuberosity^10,11 or mandibular ramus¹² have been utilized successfully for this purpose during IIP. However, with this approach comes the need for a secondary surgical site, which introduces potential clinical drawbacks, including donor site morbidity, extended chairside treatment time, and increased postoperative complications.⁹ These limitations have driven interest in alternative grafting materials that can achieve equivalent regenerative outcomes to autografts without the associated complications identified with the use of donor site autogenous bone.

This case series introduces a novel application of a laminar bone membrane (LBM) in the reconstruction of severely compromised or absent facial cortical plates at the time of IIP. This method expands the pool of candidates eligible for immediate protocols who might otherwise be excluded due to inadequate facial bone support and would require a second surgery following grafting of the defect to allow implant placement. This technique, which is distinct from the use of more conventional particulate, putty, or block graft approaches, employs an allograft bone sheet derived from human tissue as a structural shield.⁷ Because the LBM becomes part of the host’s bone, tenting the soft tissue over the site, a second surgery to retrieve a nonresorbable membrane that may have been used for guided bone regeneration (GBR) procedures, is not required.⁸ Furthermore, this technique offers an expedited timeline of approximately 3 to 4 months to final loading when used correctly as described in this article. For clarity and clinical reference, the authors designate this method the facial allograft shield technique (FAST).

Indications and Contraindications

As with any dental technique, there are indications and contraindications when considering its use in a clinical situation. FAST is indicated in situations where immediate implant placement is desired in conjunction with reconstruction of a deficient facial plate. Clinical situations that are ideally suited for the use of FAST include: type II socket defects where the facial plate is partially or completely absent, but adjacent interproximal osseous walls remain intact to provide 3-dimensional stability for the implant; cases in which adequate apical and palatal bone support exists to achieve primary stability during IPP; esthetic zone cases that need predictable maintenance of the mid-facial gingival marginal levels and support of the soft tissue; and situations where simultaneous hard- and soft-tissue augmentation is required to optimize both function and esthetics in a single-stage surgical approach.

Contraindications to the use of this technique are as follows: an active acute infection presents in the socket or adjacent tissues, where bacterial load and inflammation could compromise both graft integration and implant osseointegration; severe horizontal or vertical bone loss extends beyond the facial plate, resulting in inadequate surrounding bone for initial implant stability, including loss of proximal bone at the extraction socket; inadequate keratinized tissue is present, such that soft-tissue augmentation alone would be insufficient to achieve long-term stability without staged grafting; or there is severe soft-tissue loss requiring advanced soft-tissue grafting procedures.

With clear identification of appropriate case selection parameters, clinicians can optimize the predictability of FAST outcomes and minimize complications.

Surgical Protocol

For the FAST procedure, a standard preoperative evaluation includes a comprehensive medical and drug history, clinical and radiographic assessment, and prosthetic planning for an ideal implant position that will meet both esthetic and functional demands.

In the case series presented in this article, all six patients received premedication with 2 grams of amoxicillin orally, 1 hour before surgery. Following local anesthetic administration and the patient’s choice of sedation, atraumatic extraction of the unrestorable tooth was performed. The extraction socket was debrided with curettage and saline irrigation, then classified according to the Elian system and Chu subclassification.^13,14

Osteotomy preparation was performed with a prefabricated static navigation surgical guide, beginning with a pilot drill and expanded sequentially using an osseodensification protocol (Versah®, versah.com) appropriate for IIP. Implants (Straumann, straumann.com) were inserted in prosthetically ideal positions, achieving a final seating torque of 25 Ncm to 35 Ncm. When primary stability allowed, a healing abutment was placed for a single-stage approach.

A limited buccal envelope flap was reflected, extending horizontally and vertically approximately 2 mm beyond the defect, to accommodate the LBM (Maxxeus®, maxxeus.com). A 1 cm x 1 cm LBM was trimmed to fit the defect, overlapping onto the adjacent native ridge bone by 2 mm on either side horizontally. The coronal edge of the LBM was positioned 3 mm apical to the mid-facial gingival margin to replicate normal crestal anatomy.¹⁵ The space between the LBM and implant was then packed with particulate allograft. An amnion-chorion membrane (BioXclude®, Maxxeus) was placed over the underlying LBM and particulate allograft and under the flap margins before closure was performed with 6-0 PGA-PCL sutures (Resorba® Glycolon™, Osteogenics, osteogenics.com) using a combination of figure-of-eight and simple interrupted sutures. An immediate postoperative cone-beam computed tomography (CBCT) was taken to confirm proper positioning of the implant, gain in facial bone thickness, and adaptation of the LBM.

Patients were reviewed at 2 weeks postoperatively. One patient required delayed implant uncovery at 5 months, while the other five patients in this case series all followed a typical healing timeline. Between 2 and 5 months post-surgery, patients returned for clinical and radiographic assessment prior to definitive restoration.

Case Examples

Maxillary Anterior

A 61-year-old female patient presented with the maxillary left central incisor (tooth No. 9) fractured at the gingival margin; the tooth was deemed nonrestorable (Figure 1). A CBCT was taken, and analysis of the cross-section noted a lack of facial bone, classifying the socket as type IIb (Figure 2). Treatment, as outlined above, was discussed with the patient, who agreed with the proposed recommendations and signed the consent form. The tooth was then extracted and the surgical protocol described above was followed.

In this particular case, a Straumann® 3.3 mm x 12 mm BLT (Bone Level Tapered) NC (Narrow CrossFit) SLActive® implant was placed. A radiograph was taken to confirm the implant position relative to the adjacent anatomy (Figure 3). Insertion torque was 25 Ncm, and a single-stage approach was utilized and a healing abutment placed. A 1 cm x 1 cm LBM was trimmed to fit the site (Figure 4). The LBM was then placed in the buccal envelope created between the flap and overlying the ridge, not in contact with the implant (Figure 5). Particulate allograft was densely packed between the facial aspect of the implant and the LBM. An amnion-chorion membrane was placed as described above. The flap was reapproximated and secured with sutures (Figure 6). A CBCT was taken to document the implant placement and overlying grafting with the LBM, demonstrating coverage of the facial aspect of the implant (Figure 7).

The patient was seen at the 2-month interval. Upon removal of the healing abutment the soft-tissue was healthy with no inflammation noted, and implant stability quotient (ISQ) testing noted a 70/70 reading on the implant indicating the restorative phase could be initiated (Figure 8). A CBCT was taken, and the cross-section view revealed that the facial aspect of the implant was covered with bone (Figure 9). The implant was restored with a definitive restoration (Figure 10).

Mandibular Anterior

A 64-year-old male patient presented with mobility on the mandibular left lateral incisor (tooth No. 23). The patient indicated he had prior endodontic treatment on the tooth. A radiograph was taken and significant bone loss crestally was noted on the tooth with a periapical lesion present (Figure 11). A CBCT was taken and in cross-section view it was noted that there was no bone covering the facial aspect of the tooth and the socket was classified as type IIb (Figure 12). Treatment, as noted above, was discussed with the patient who agreed with the proposed recommendations and signed the consent form. The tooth was then extracted and the surgical protocol outlined above was followed.

The site was prepared, and a Straumann® 2.9 mm x 12 mm BLT SC (Small CrossFit) SLActive implant was placed at 30 Ncm insertion torque (Figure 13). A 1 cm x 1 cm LBM was trimmed and fitted to the defect as previously described (Figure 14). Particulate allograft was placed between the LBM and implant. Because of the large amount of bone grafting required it was decided not to follow a single-stage approach, and a cover screw was placed on the implant and the site closed with sutures. A CBCT was taken to document the implant placement and resulting bone gain of the facial aspect of the defect (Figure 15).

At 5 months post-surgery the patient was seen for uncovering of the implant. Following flap elevation, it was noted that a thick facial ridge was present completely encasing the implant (Figure 16). Bone was removed to expose the cover screw, a healing abutment was placed, and the flap secured with sutures. The patient returned at 2 weeks to ensure adequate soft-tissue healing had occurred (Figure 17). A CBCT was taken, and analysis of the cross-sectional view demonstrated bone covering the facial aspect of the implant and restoring the ridge to normal contours (Figure 18). The implant was restored with a definitive restoration (Figure 19 and Figure 20).

Results

At the time of definitive loading in all six of the cases in this study, the implant sites demonstrated stable peri-implant conditions. Clinical probing revealed normal sulcular depths, with no bleeding on probing and satisfactory plaque control. Peri-implant soft tissues were healthy in color and texture. Additionally, the soft tissue was harmonized and exhibited a natural scalloped contour consistent with the patient’s adjacent gingival architecture. The gingivae had a lack of inflammation, was firm, resilient, and appropriately stippled, without signs of apical migration of the free gingival margin. No clinical evidence of infection, such as suppuration, erythema, or edema, was observed at any of the sites in each of the study cases.

Implant stability was confirmed using resonance frequency analysis, with ISQ values exceeding 70 in both the buccolingual and mesiodistal directions, indicative of high primary stability. The mean buccolingual ISQ was 75.2 ± 4.20 (interquartile range [IQR]: 71.5–79.5), while the mean mesiodistal ISQ was 77.6 ± 4.77 (IQR: 73–81). None of the implants exhibited clinical mobility.

Radiographic evaluation (CBCT cross-section) at the time of final loading revealed a mean facial bone width gain of 2.93 mm ± 1.10 mm (IQR: 2.13–3.49) at the alveolar crestal level. At the mid-implant level, mean facial bone gain was 2.95 mm ± 1.29 mm (IQR: 1.9–4.1). One patient presented a type IIc apical defect; for that case, bone gain measured 3.58 mm at the apical level of the implant. None of the six implants in this case series demonstrated radiographic evidence of peri-implant radiolucency. Following confirmation of satisfactory clinical and radiographic outcomes, patients were referred to their restorative dentists for delivery of the definitive prosthesis. Final restorations were torqued to 35 Ncm.

Discussion

Immediate implant placement has evolved into a reliable and predictable treatment option, particularly for patients seeking shorter treatment time with earlier restoration of function and esthetics.¹⁶ Success, however, is highly contingent on adequate alveolar support, most critically the presence of a stable facial plate.⁶ In the absence of a facial aspect to the ridge, a staged restorative approach is required, extending treatment duration and increasing patient inconvenience.

The Elian socket classification system (with Chu subclassification) has proven valuable in identifying clinical sites that are at greater risk for recession facially, helping to guide treatment selection decisions.^13,14 Type II sockets, characterized by intact soft tissue but partial or complete facial osseous plate loss, present particular challenges. These cases typically have been approached with bone augmentation and delayed implant placement.⁶ A clinical trial conducted by Kolerman et al demonstrated that the use of mineralized freeze-dried bone allograft particles with a non-crosslinked collagen membrane during IIP had a positive effect on preserving the crestal bone level surrounding the implant.¹⁶ Evidence suggests that, with meticulous hard- and soft-tissue management, IIP in these sockets can achieve survival rates exceeding 98%.^17,18 Autogenous bone grafting remains the benchmark due to its combination of osteogenic, osteoinductive, and osteoconductive properties.9 Predictable results have been documented using ramus bone chips,¹⁹ maxillary tuberosity blocks,^11,12,20 or cortical–cancellous composite grafts. Qian et al in their 1-year prospective case series reported favorable esthetic results when using a GBR technique with bovine bone particles and a simultaneous connective tissue graft for IIP in the presence of a buccal bony dehiscence.²¹ Additionally, cancellous block allografts that have been shaped to approximate a recipient defect have been successfully employed in IIP in the anterior maxilla.²² While effective, these methods require a donor site, introducing additional patient morbidity, longer surgical time, and increased patient postoperative discomfort.

The use of allogeneic grafts has been extensively investigated as an alternative to autogenous bone in oral surgical applications. In 2018, Kloss et al reported no statistically significant difference in bone volume gain when comparing autogenous and allograft materials for the treatment of single-tooth defects with delayed implant placement.²³ A separate comparison of autologous and allogeneic bone block grafts, in a delayed placement protocol, found no measurable difference in esthetic outcomes between the two treatment modalities.²⁴ Patients in the allograft group notably reported less postoperative discomfort and expressed a greater willingness to undergo similar treatment again in the future.²⁴ Those findings suggest that when appropriately selected, allografts may provide clinical outcomes comparable to autografts while offering advantages such as shorter procedure times, unlimited supply, elimination of donor site morbidity, and potentially fewer complications. These benefits have propelled interest in allograft-based solutions capable of producing comparable outcomes without the need for autogenous harvesting.^23,24

The approach used in the present case series, designated the facial allograft shield technique (FAST), enables immediate reconstruction of the facial plate during IIP without the need for autogenous grafts or a nonresorbable membrane or titanium mesh to tent the defect. Overlap of the LBM onto adjacent native bone may further enhance implant stability and integration during healing. Most importantly, FAST appears to be less technique-sensitive while still delivering predictable results than traditional autogenous block grafts that require screw fixation to the underlying ridge. The facial bone width gains at both crestal and mid-implant levels achieved in the present case series suggest reliable regeneration and contour stability.

Historically, LBMs have been used for the regeneration of molar furcation defects,²⁵ GBR procedures,^26,27 and socket sealing during implant placement.²⁸ These grafts can be derived from either xenogeneic or allogeneic sources. Schuh et al demonstrated the successful use of a xenogeneic LBM for anterior ridge reconstruction in cases with inadequate alveolar width.²⁹ While xenogeneic LBMs have shown clinical efficacy, their primary drawback is the extended time required for complete bony consolidation compared to allogeneic sources.³⁰ The LBM is semi-rigid yet adaptable, providing structural stability that maintains space over the defect, unlike resorbable membranes, which are prone to collapse. Placement requires only a limited envelope flap without fixation screws or extensive tissue reflection, resulting in minimal morbidity. As an allograft, the material provides osteoconductive properties and it undergoes complete resorption within 12 to 14 months converting to host bone. The LBM can be easily trimmed to allow customization to a particular site, making it suitable for variable defect morphologies that may present.

In the cases presented in this series, the absent facial plate in IIP sites was reconstructed using thin LBMs in conjunction with cortico-cancellous mineralized allograft particles and an acellular collagen membrane (ie, amnion-chorion membrane). Demineralized cortical bone, as utilized in LBMs, offers both dependable mechanical support and structural adaptability, making it well-suited for facial plate reconstruction. LBMs are produced from a strip of cortical bone processed similarly to demineralized freeze-dried bone and represent a subset of demineralized allografts.²⁵ An amnion-chorion membrane was placed over the graft in the final step prior to closure in these cases.31 Multiple studies endorse the utilization of an amnion-chorion membrane as a viable substitute for existing methods in periodontal and oral soft-tissue regeneration procedures.31 Li found that these membranes are easily manageable, possess flexibility, and promote bone regeneration, without the infiltration of fibrous tissue.³² Additional benefits of an amnion-chorion membrane include antibacterial properties33 and the ability to release growth factors.³⁴

In addition to the two patients shown as examples, four other patients were also treated with the FAST technique (a total of three women and three men; median age: 73 years), undergoing extraction with IIP and reconstruction of the absent facial plate utilizing an allograft LBM. Each patient subsequently completed a full dental rehabilitation with an implant-supported crown, thus a total of six implants were placed in the case series (Table 1 and Table 2). As the case series demonstrated, this technique provided predictable results and can be considered when the absence of facial plates might potentially hinder IIP at the time of extraction.

Conclusion

Traditionally, immediate implant placement in sites with partial or complete facial plate loss has been undertaken cautiously, often with a staged approach utilizing ridge reconstruction before implant placement. The facial allograft shield technique (FAST) using an allograft laminar bone membrane offers a predictable, minimally invasive alternative procedure that allows simultaneous facial plate reconstruction and implant placement while eliminating donor site morbidity. In the present case series, FAST consistently produced stable hard- and soft-tissue contours, high implant stability, and positive patient-reported outcomes in a condensed treatment timeline with the ability to immediately temporize. Radiographic evaluation demonstrated measurable facial bone width gain at both crestal and mid-implant levels, underscoring the potential of the laminar bone membrane as both a structural scaffold and biologically compatible regenerative material.

While these early results are promising, the encouraging outcomes reported here should be confirmed through long-term prospective studies. If substantiated, FAST may represent a significant, less invasive advancement for managing type II socket defects with immediate implant placement, particularly in the esthetic zone.

DISCLOSURE

The authors had no disclosures to report. They received no funding or material support for this article.

AUTHOR CONTRIBUTIONS

Dr. Edibam performed the surgical procedures and gathered data. Drs. Eyen, Salomon, and Caponio helped compile and review the data and assisted with writing the article. Dr. Kurtzman wrote the draft and incorporated edits for the final manuscript. He was compensated for assisting with writing the article.

ABOUT THE AUTHORS

Naushad Edibam, DMD
Implant Course Director, Department of Oral and Maxillofacial Surgery, Yale New Haven Hospital, New Haven, Connecticut

Samantha Eyen, DDS
Resident, Department of Oral and Maxillofacial Surgery, Yale New Haven Hospital, New Haven, Connecticut

David Salomon, DDS
Clinical Instructor, Department of Oral and Maxillofacial Surgery, Yale New Haven Hospital, New Haven, Connecticut

Gregori M. Kurtzman, DDS
Private Practice, Silver Spring, Maryland

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