Managing Palatal Bone Loss Using a Combined Therapy Approach: A Case Report

Alveolar bone loss is commonly associated with underlying chronic inflammatory conditions, including periodontitis, which can eventually lead to tooth loss.¹ Periodontal disease remains one of the most prevalent chronic conditions, with epidemiological data suggesting that nearly 42% of adults aged 30 years and older in the United States have periodontitis.² This inflammatory process leads to the irreversible destruction of the supporting bone, often resulting in a “hopeless” tooth prognosis characterized by vertical and horizontal bone loss. Often, localized anatomical aspects of the roots can serve as potential etiological factors for the development and advancement of the periodontal disease.³ However, the defects are mainly present on the buccal or lingual sites and have rarely been reported on the palatal site of monoradicular posterior teeth. Thus, when planning treatment for a patient with a significant palatal defect, preserving and regenerating enough bone for implant placement is essential to support the success and long-term stability of the final restoration.

Approximately 2 mm of buccal bone and 1 mm of palatal/lingual bone are necessary to ensure the implant’s stability and prevent future bone loss.^4,5 Alveolar ridge preservation (ARP) is a procedure used to maintain adequate bone volume and mitigate the alveolar ridge volume loss observed at the extraction site during spontaneous healing.⁶ While strong evidence exists supporting the success of ARP in preserving the dimensions of the alveolar ridge, the performance of specific biomaterials has only moderate evidence due to limited standardization and reporting.⁷ Thus, choosing an appropriate biomaterial for ARP is imperative for clinicians.

ARP utilizes hard-tissue biomaterials, such as bone grafts, to serve as a scaffold for new bone growth, and soft-tissue biomaterials, such as collagen membranes, to protect the socket and allow for undisturbed bone growth.⁸ Following tooth extraction and placement of bone graft in the empty socket, osteoprogenitor cells and osteoblasts from surrounding bone tissue attach to the surface of the osteoconductive graft particles, serving as a foundation to form new bone.⁹ Given the complex biology of oral regeneration, a variety of factors must be considered when choosing a biomaterial for ARP, including biological and mechanical properties, bone formation potential, resorption rate, patient comfort, long-term stability, and cost-effectiveness.¹⁰

Four major bone graft sources for ARP are autogenous, allogenic, xenogeneic, and alloplastic grafts. Autogenous cortico-cancellous bone harvested from the patient’s body is considered the “gold standard” of bone grafting because of its osteogenic potential.⁹ However, its fast reabsorption, the need for an additional surgical site, and potential comorbidity from the surgical donor site have limited its application in ARP procedures.¹¹

Allogenic bone, which is procured from human cadaveric donors and processed by accredited tissue banks, is the most extensively documented alternative and avoids donor-site morbidity entirely. It is supplied as mineralized freeze-dried bone allograft (FDBA), which acts primarily as an osteoconductive scaffold, or as demineralized freeze-dried bone allograft (DFDBA), in which acid demineralization exposes bone morphogenetic proteins within the organic matrix and confers osteoinductive potential.¹²

Reported drawbacks of allogenic bone include batch-to-batch variability in donor selection and processing among tissue banks, the theoretical risk of disease transmission, and patient reluctance to accept human-derived tissue.^13,14 Also, particulate allografts generally require a barrier membrane or comparable coverage to contain the graft in the socket, adding to the procedure.¹⁵

These limitations have led to the development of alternative grafting materials that aim to overcome these challenges while maintaining effectiveness. One novel graft material is a combined bone grafting plug (OsteoGen® Plug, Impladent Ltd., impladentltd.com), which is both xenogeneic and alloplastic. The resorbable calcium apatite (alloplastic component) mimics the inorganic structure of natural bone, while the collagen from bovine Achilles tendon (xenogenic component) delivers blood to the graft and provides a scaffold for keratinized tissue growth over the site.¹⁶ Along with these healing benefits, this xenograft–alloplastic biomaterial plug features a block structure that eliminates the need for an additional membrane to contain particles in the extraction site.

For a site with anatomical limitations, such as the palatal vault and associated immobile palatal soft tissue, this plug offers the stability and ease of use needed when accessing a narrow extraction site situated within complex palatal architecture. The presence of existing dental implants adjacent to a failing tooth can also create a challenging surgical site. In the case presented here, the xenograft–alloplastic plug was particularly advantageous because its contained block structure allowed for graft placement within the limited space between the osseointegrated implants at the Nos. 3 and 5 positions without the need for an additional membrane, helping minimize disruption to the stability of the neighboring implants.

In such challenging environments, combining the regenerative potential of different biomaterials can also facilitate successful subjective and objective outcomes. While the resorbable xenograft–alloplastic biomaterial mimics the components of natural bone,^17,18 hydrating the plug with recombinant human platelet–derived growth factors (rhPDGF-BB), such as GEM 21S® (Geistlich/Lynch Biologics, lynchbiologics.com), enables the graft to function as a potent mitogen and stimulate the proliferation and migration of osteoblasts, periodontal ligament cells, and mesenchymal progenitor cells while promoting angiogenesis.^19,20

Thus, this case report aims to demonstrate the effectiveness of this novel combination of biomaterials in facilitating predictable functional and esthetic outcomes for ARP and subsequent implant-supported restoration at site No. 4 with a significant palatal defect bounded by two implants.

Case Presentation

A 60-year-old female patient presented with a chief complaint of mobility and localized pain in the maxillary right quadrant. Medical history revealed hypercholesterolemia managed via medication. The patient was otherwise healthy and a non-smoker.

Clinical examination of tooth No. 4 revealed grade 3 mobility and localized increased probing depths with bleeding on probing. An inflamed gingival margin was noted on the buccal and palatal aspects of the tooth (Figure 1 and Figure 2). Preoperative 3-dimensional radiographic imaging confirmed a significant circumferential combined vertical and horizontal bone defect around the root due to a horizontal root fracture (Figure 3 and Figure 4). The root curvature contributed to the severity of the palatal bone loss. Due to the extent of attachment loss, the tooth prognosis was deemed hopeless.²¹

Phase 1: Extraction and Alveolar Ridge Preservation

Taking the patient’s medical and dental history into consideration, extraction with ARP was selected as the most appropriate treatment plan. Prior to the procedure, the patient had already reviewed and followed preoperative instructions. Baseline vital signs were obtained, and informed consent was secured after a thorough discussion of the proposed procedure, alternatives, and potential complications.

The patient was premedicated with acetaminophen 500 mg and ibuprofen 600 mg to reduce inflammation and mitigate discomfort. Amoxicillin 500 mg was also administered to protect against bacterial infection at the extraction site. A 20% benzocaine topical anesthetic gel was applied on the buccal vestibule of tooth No. 4, followed by local anesthesia administered via infiltration using 4% articaine hydrochloride with 1:100,000 epinephrine (Septocaine®, Septodont, septodontusa.com) on both the buccal and palatal aspects.

Tooth No. 4 was atraumatically extracted in one piece. Upon clinical inspection, significant inflammation and granulation tissue were visible on the root surface. Upon debridement, it was confirmed that, as initially seen on the cone-beam computed tomography (CBCT) scan, the palatal bone was missing in the coronal third of the socket. The defect was treated with the osteogenic collagen plug (slim version), trimmed, and hydrated with rhPDGF-BB. The plug was packed into the defect to the gingival margin using a special plugger (OsteoGen stainless steel plugger), and no barrier membrane was used. The site was stabilized with a polytetrafluoroethylene (PTFE) figure-of-8 suture (Figure 5 through Figure 9).

The patient felt comfortable and was given postoperative instructions, which included taking ibuprofen and acetaminophen as needed for 2 to 3 days.

At the 11-day follow-up appointment, sutures were removed. Soft-tissue healing was uneventful, and the patient reported no discomfort (Figure 10 and Figure 11). Three months post-procedure, healing appeared successful, and implant placement was scheduled for the 6-month mark post-extraction.

Phase 2: Implant Placement

At 6 months, a 3-dimensional radiographic and clinical examination confirmed adequate ridge width and osseous healing, making the site suitable for implant placement (Figure 12). The patient was premedicated with 400 mg of ibuprofen and 1,000 mg of acetaminophen. A full-thickness flap was carefully elevated, and a 3.3 mm x 10 mm dental implant (Straumann® Bone Level Tapered [BLT™], Straumann, straumann.com) was placed in a prosthetically driven position with an initial torque of 35 Ncm (Figure 13 through Figure 19).

Due to the delicate palatal architecture and to ensure the health of the neighboring implants, a two-stage implant placement was used to ensure successful osseointegration and long-term stability. Following implant insertion, a closure cap was placed, and the overlying soft tissue was primarily closed with PFTE sutures. The patient was instructed to use 0.12% chlorhexidine gluconate oral rinse (Peridex™, Solventum, solventum.com) and continue with the antibiotic protocol outlined in the postoperative instructions.

At 1 week, sutures were removed, and the area was debrided with 0.12% chlorhexidine gluconate oral rinse. The patient reported no pain or discomfort. One-month post-implant placement, soft tissue was completely closed. The second-stage implant uncovery was planned for 5 months after the initial implant placement.

Phase 3: Second-Stage Surgery and Restoration

During the second-stage surgery (Figure 20 through Figure 23), topical anesthesia was applied, followed by infiltration with 4% articaine hydrochloride with 1:100,000 epinephrine to the buccal and palatal regions of tooth No. 4. A full-thickness flap was reflected to uncover the implant, remove the cover screw, and place a healing cap. The authors appreciated the good soft-tissue healing and adequate ridge width achieved without the need for additional soft-tissue grafting. Later, the dental implant was restored with a screw-retained zirconia prosthesis. The final peri-implant tissues demonstrated healthy tissue and adequate keratinized mucosa (Figure 24 through Figure 26).

Overall, the healing was uneventful. Within 6 months after ARP, adequate ridge preservation and osseous healing were observed clinically and radiographically, providing an optimal foundation for implant placement. Additionally, the stability and healthy architecture of the surrounding keratinized soft tissue further demonstrated the effectiveness of the combination of biomaterials in contributing to predictable esthetic and functional outcomes for the final implant-supported restoration.

Discussion

The management of advanced palatal bone loss in the maxillary premolar region presents a unique clinical challenge, particularly when adjacent dental implants are present. Unlike buccal defects, which are more commonly encountered and amenable to flap advancement, palatal deficiencies occur due to the limited elasticity and immobile nature of palatal soft tissue.²² In the present case, the palatal defect associated with tooth No. 4 resulted in a compromised socket morphology that traditionally would be considered unfavorable for predictable implant placement without extensive augmentation.

To achieve adequate ridge dimensions to enable an implant-supported restoration, ARP was performed to facilitate the implant’s stability and prevent bone resorption. Although strong evidence for the success of ARP is documented in current literature, evidence for the clinical performance of specific biomaterials (ie, autogenous, allogenic, xenogenic, and alloplastic grafts) is only moderate, primarily due to heterogeneity in study design and material reporting.⁷ Thus, when choosing a biomaterial for ARP—especially when morphological limitations are involved—clinicians must consider a range of factors, such as biological and mechanical properties, bone formation potential, resorption rate, patient comfort, long-term stability, and cost-effectiveness. In this case, the structure of the xenograft–alloplastic plug offered the stability and ease of use required when accessing the narrow extraction site situated within the complex palatal architecture and limited space between the osseointegrated implants at the Nos. 3 and 5 positions. Eliminating the need for an additional membrane also minimized disturbance to the stability of neighboring implants.

The proposed regenerative approach, which involved hydration of the scaffold with a growth factor, was selected to leverage the combined properties of both of these biomaterials in preserving native anatomy while reducing surgical complexity. The application of rhPDGF-BB has been extensively studied and shown to promote chemotaxis, proliferation, and differentiation of osteoblasts and mesenchymal cells.^23,24 When delivered with a collagen-based scaffold such as the xenograft–alloplastic biomaterial, the combination provided both biologic stimulation and space maintenance, facilitating early clot stabilization and subsequent bone formation.

The favorable outcome observed in this case is consistent with existing evidence supporting the use of rhPDGF-BB in ARP and implant site development, particularly in sites with compromised biology.²⁵ However, factors such as the presence of thick phenotype, adequate keratinized tissue on the palatal aspect, and a relatively shallow socket morphology may independently explain the favorable outcomes observed. Histologic confirmation and long-term comparative data are still needed to assess the peri-implant soft-tissue and bone stability and clarify the role this combination of biomaterials played in the success of this case.

Within these limitations, this case still demonstrates that a combination of an osteogenic collagen scaffold hydrated with rhPDGF-BB can be an effective and minimally invasive solution for managing complex palatal defects in proximity to existing dental implants. This approach may offer clinicians a predictable alternative for site development in challenging maxillary scenarios while minimizing patient morbidity and surgical complexity. Another consideration is the reduced cost of biomaterials when using a scaffold hydrated with growth factor compared to the use of bone graft, membrane, and hydration with growth factor. Further studies are recommended to determine the long-term outcomes, including both clinician-reported and patient-reported outcomes.²⁶

Conclusion

This case report highlights the use of a combined therapy of an osteogenic collagen scaffold hydrated with rhPDGF-BB in achieving predictable clinical outcomes in ARP procedures and implant-supported restorations. The rehabilitation of tooth No. 4 in an environment with significant palatal defects and bounded by implants suggests the potential for this biomaterial combination to support favorable outcomes in anatomically challenging ARP cases. Future randomized controlled trials comparing osteogenic collagen scaffold and growth factor–based approaches, with histologic data, could provide further clinical and radiographic insights to guide clinicians managing similar limitations.

ACKNOWLEDGMENT

This report was partially supported by Tufts University School of Dental Medicine, Department of Research Administration. The authors thank Prof. Eileen Doherty and Ann-Marie Billig, as well as the team at The Perio Studio, Rose McKenna, and Estar R. Vallapu, BDS.

ABOUT THE AUTHORS

Nika Mehrnia, DDS

Research Fellow, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts; Graduate Scholar, ADA-Forsyth Institute, Somerville, Massachusetts; Private Practice limited to Periodontology and Implant Dentistry, Boston, Massachusetts

Amir Kellini, DMD Candidate

Tufts University School of Dental Medicine, Boston, Massachusetts; Private Practice limited to Periodontology and Implant Dentistry, Boston, Massachusetts

Jessica Sun Reilly, BS

Research Associate, Tufts University School of Dental Medicine, Boston, Massachusetts; Private Practice limited to Periodontology and Implant Dentistry, Boston, Massachusetts

Samar Shaikh, BDS, DMD, MS

Assistant Professor, Department of Periodontology, Tufts University School of Dental Medicine, Boston, Massachusetts; Diplomate, American Board of Periodontology

Irina F. Dragan, DMD, DDS, MS, eMBA

Adjunct Associate Professor of Periodontology, Tufts University School of Dental Medicine, Boston, Massachusetts; Lecturer, Department of Oral Medicine, Infection, and Immunity, Harvard School of Dental Medicine, Boston, Massachusetts; Private Practice limited to Periodontology and Implant Dentistry, Boston, Massachusetts

Figures and Images

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Figure 1

Pretreatment buccal view of tooth No. 4.

Figure 2

Pretreatment occlusal view of tooth No. 4.

Figure 3

Pretreatment periapical radiograph of tooth

Figure 4

Pretreatment CBCT from the mesial aspect of tooth No. 4. Note bone defect around the root (red arrow).

Figure 5

Socket of tooth No. 4 post-extraction.

Figure 6

Periapical radiograph of the extraction site.

Figure 7

Bone grafting material was hydrated with biologics and placed in the extraction site.

Figure 8

PTFE sutures were placed over the extraction site.

Figure 9

Periapical radiograph showing the biomaterial placed in the extraction site.

Figure 10

Follow-up at 2 weeks, before suture removal.

Figure 11

Follow-up at 2 weeks, after suture removal.

Figure 12

CBCT scan at 6-month follow-up showing adequate ridge dimensions (left) and implant planning on the scan (right).

Figure 13

Occlusal view of the flap design for implant placement 6 months after extraction and bone grafting.

Figure 14

The flap was retracted buccally, exposing the alveolar ridge.

Figure 15

Occlusal view of the osteotomy for implant placement.

Figure 16

Periapical radiograph showing the guiding pin during the osteotomy.

Figure 17

The 3.3 mm x 10 mm bone-level tapered implant was placed into the osteotomy.

Figure 18

Occlusal view of PTFE sutures, highlighting primary closure.

Figure 19

Periapical radiograph of the implant post-placement.

Figure 20

Intraoral scan showing buccal view of the alveolar ridge before implant uncovering.

Figure 21

Intraoral scan showing occlusal view of the alveolar ridge before implant uncovering.

Figure 22

Occlusal view of the implant with the healing cap placed post-uncovery.

Figure 23

Periapical radiograph showing the uncovered implant with healing cap.

Figure 24

Buccal view of the final implant-supported restoration.

Figure 25

Occlusal view of the final implant-supported restoration.

Figure 26

Periapical radiograph of the final implant-supported restoration.