Utilizing Chronic Intrasocket Granulation Tissue for Ridge Preservation: A Novel Approach

A variety of protocols have been introduced for restoring the ridge contours of periodontally compromised teeth to be extracted.^1–3  In the literature, the most common modality for this is a guided bone regeneration procedure after a sufficient healing period following tooth extraction.⁴  However, nonintervened healing after extracting a periodontally compromised tooth sometimes leads to a huge loss of not only hard tissue but also soft tissue.

The clinical benefits of alveolar ridge preservation were recently highlighted, especially as it demonstrates a reduced odds ratio of hard-tissue augmentation at the time of implant placement compared with nonintervened healing.⁵  Despite a heterogeneity of ridge preservation procedures,⁶  ridge preservation always requires meticulous debridement of the socket to expose sound socket walls. Such is based on the belief that the socket-lining soft tissue is infected granulation tissue, which has been applied to minimally destructive sockets (less than 50% bone destruction in facial wall) in previous clinical studies.⁵ 

However, a different scenario can be posed involving the socket with a periodontally compromised tooth. Pathogenetically, the pocket epithelium migrates progressively in an apical direction because of the combination of microbial attacks and host defense mechanisms.⁷  With the deepening of the periodontal pocket, the pocket epithelium seems to become thick and dense, with some coronal parts resembling oral epithelium. In this situation, such altered pocket epithelium may be used as a part of the flap. When such a method is used for ridge preservation or ridge augmentation at the time of extraction, additional soft-tissue surgery for closing the socket entrance is unnecessary, and the shift of the mucogingival junction becomes minimal.

The aim of the present case report was to describe a novel technique using chronic intrasocket granulation tissue for alveolar ridge preservation in a periodontally compromised extraction site.

All surgeries in the present case report were performed by 1 periodontal specialist (Y.S.H.).

A 60-year old male patient required extraction of #14, #15, and #16 teeth (according to the tooth numbering system of the American Dental Association) and implant placement (Figure 1a). On radiographs using cone-beam computerized tomography (CBCT), severe bone destruction extending to the root apex was observed (Figure 1b through d).

Following local anesthesia using posicaine with 1:100 000 epinephrine (Novovol, Ontario, Canada), the teeth were gently removed using forceps. The socket was lined with thick soft tissue, particularly on #14 (Figure 1e). Two vertical incisions along the distal surface of #13 and 1 horizontal incision on the buccal aspect between #14 and #16 were made (Figure 1f). Vertical incisions included the distal papilla of #13. To maintain the continuation between the side of the flap and socket-lining soft tissue, the incision line was made on the buccal keratinized tissue on intact buccal bone. The flap including the intrasocket granulation tissue was elevated from the buccal aspect toward the palate, and then the soft-tissue remnant on the socket walls was thoroughly debrided using a surgical curette. Deproteinized bovine bone mineral (Bio-Oss, Geistlich Parma, Wolhusen, Switzerland) was applied on the #14 and #15 areas to restore the ridge contour (Figure 1g). No barrier membrane was used. Subsequently, the flap was repositioned, rendering a shift of the intrasocket granulation tissue to the socket entrance. The flap was sutured using 6-0 Nylon (Ailee Co, Ltd, Busan, Korea; Figure 1h). The patient was prescribed antibiotics and analgesics for 7 days and instructed to use a chlorohexidine gargle solution (Hexamedine, Bukwang, Seoul, Korea).

The suture was removed after 7 days. The socket entrance was covered with newly formed granulation tissue (Figure 1i). No infection or protrusion of the bone substitute material was noted. At 3 weeks, epithelialization of the surgical site was almost complete (Figure 1j). The mucogingival junction of the surgical site was maintained compared with the presurgical situation.

At 4 months (Figure 1k), implant placement was performed. Following flap elevation, a well-formed ridge contour was observed (Figure 1l). One-step undersized drilling was performed to ensure good primary stability. Two-bone level implants (Luna Ø5.0 × 8.5 mm, Shinhung, Seoul, Korea) were placed according to the manufacturer's guideline,^8,9  and cover screws were connected to the implants for submerged healing (Figure 1m). After 3 months, healing abutments were connected. A cement-retained prosthesis was delivered (Figure 1n).

A 57-year-old male patient required extraction of #4 and #5 teeth and implant placement (Figure 2a). On CBCT, severe bone destruction exceeding to the middle third of the root was observed. Notably, #4 presented with pathologic migration.

The principle of the surgery was identical to case 1. The continuation between the flap and the intrasocket granulation tissue was maintained by means of the horizontal incision on the palate. The flap was then made following 2 vertical incisions along the distal surface of #6 (Figure 2b). After flap elevation, deproteinized bovine bone mineral with a 10% collagen (Bio-Oss collagen, Geistlich Parma) was applied to the #4 and #5 areas (Figure 2c). Subsequently, the flap was repositioned and sutured using 5-0 and 6-0 Nylons (Figure 2d). The #4 area was completely closed by intrasocket granulation tissue, but the #5 area presented a partial exposure of the grafted bone material. A collagen matrix (Mucograft seal, Geistlich Parma) was additionally applied on the socket entrance of #5 and sutured. The suture was removed after 1 week. Newly formed soft tissue completely covered the socket entrance (Figure 2e). No adverse events were observed. At 10 weeks (Figure 2f), bone-level implants were placed on the #5 (Ø4.0 × 10 mm, Shinhung), #4 (Ø 4.5 × 10 mm, Shinhung), and #3 areas (Ø5.0 × 10 mm, Shinhung), and healing abutments were connected for nonsubmerged healing (Figure 2g). After 5 months, a cement retained prosthesis was delivered (Figure 2h).

A 68-year-old male patient required extraction of #15, which was an abutment tooth of a fixed partial prosthesis (Figure 3a). Gingival recession had almost reached the apex of #15. On CBCT, severe bone destruction was observed on both buccal and palatal aspects.

After extraction, thick intrasocket granulation tissue was observed (Figure 3b). Because of the substantial loss of bone walls both buccally and palatally, the incision for connecting the flap with intrasocket granulation tissue was made on the mesial side of the socket (Figure 3c). Small cut-back incisions on the buccal and palatal areas were performed at the edge of the mesial incision. The flap, including the lining soft tissue, was elevated from the mesial aspect of the socket toward the distal aspect. Deproteinized bovine bone mineral (Bio-Oss, Geistlich Parma) was applied for restoring the ridge contour, and the flap was subsequently sutured using 5-0 Nylon (Figure 3d). After 1 week, the suture was removed. Partial exposure of bone substitute material was observed, but epithelialization had progressed from the marginal tissue (Figure 3e). Complete epithelialization was achieved at 4 weeks (Figure 3f).

At 5 months, bone-level implants were placed on the #14 (Luna Ø5.0 × 8.5 mm, Shinhung) and #15 areas (Luna Ø5.0 × 10 mm, Shinhung), and healing abutments were connected for nonsubmerged healing (Figure 3g). A sinus floor elevation procedure was performed for #14 area, but there was no need for additional augmentation for the #15 area. After 4 months, a cement retained prosthesis was delivered (Figure 3h).

All cases were carefully monitored clinically and radiographically. No patients reported functional problems. Probing depth was measured at <4 mm in all implants. No redness or swelling was observed or reported. Panoramic radiographic views (taken at 16, 12, and 30 months following the final prosthesis insertion in patients 1, 2, and 3, respectively) exhibited stable marginal bone levels in all patients (Figure 4). CBCT scans also revealed stable marginal bone level and adequate incorporation of the graft in all 3 patients (Figure 5).

The present case report demonstrates that the use of chronic intrasocket granulation tissue as part of the periodontal flap can be a promising option for extraction socket management for periodontally compromised teeth.

All included teeth in the present study demonstrated a substantial loss of the periodontal ligament apparatus to the apical area of the teeth. The clinical impression of intrasocket granulation tissue seemed slightly different from the pocket epithelium. This tissue was thick and dense and thus could be used for a part of the periodontal flap. In previous studies, such tissues were referred to as “intrasocket reactive soft tissue” and were composed of long junctional epithelium and granulation tissue.^10,11  The authors demonstrated that this tissue was useful for primary flap closure in managing an extraction socket with severe bone loss. However, unlike the present cases, that study did not involve flap elevation but instead scraped off the intrasocket granulation tissue from bony walls without providing the specifics of how to perform the procedure. The advantages of elevating the flap in the present protocol are as follows: (1) more accurate separation of intrasocket granulation tissue from bone walls can be achieved, (2) more thorough intrasocket debridement is now possible by means of better visibility, (3) the loss of ridge contour can be augmented close to the original contour, and (4) the present protocol is suitable for not only single extraction cases but also multiple extraction cases.

The most important aspect of the present approach is the location of the primary incision. The primary incisions in 3 cases were site specific: buccally in case 1, palatally in case 2, and proximally in case 3. This difference was based on the extension of intrasocket granulation tissue, extent of bone destruction, area-specific amount of keratinized tissue, and feasibility of instrumentation. To ascertain the aforementioned, CBCT and a thorough clinical examination were performed. Based on such information, a primary incision was made on the keratinized tissue-existing aspect with a sound bone plate for (1) facilitating the separation of intrasocket granulation tissue without tearing and (2) preventing flap dehiscence.

Suture materials for intrasocket granulation tissue should be thin, because thick material may interfere with blood flow in this tissue. Based on the experiences of the present authors, 6-0 material seems suitable. On other areas, 5-0 material was used.

The healing of soft tissue after the present approach seems rapid. Within 3–4 weeks, the socket entrance was completely epithelized with a good quality of keratinization, which is in line with previous studies using so-called intrasocket reactive soft tissue.^10,11  One can argue about the necessity of a barrier membrane underneath the intrasocket granulation tissue, but the present authors repeatedly experienced flap dehiscence when a barrier membrane was used. One clinical study investigated the impact of incision location for barrier membrane exposure in guided bone regeneration, demonstrating that thin gingiva (1.1 mm) led to higher exposure when a palatalized or lingualized incision was made.¹²  The authors of that study suspected the impairment of collateral blood supply by the barrier membrane in thin gingiva. The flap design of the present approach is similar to the design using palatalized/lingualized incision, and the intrasocket granulation tissue is not homogenously thick and dense. Thus, such aspects might negatively influence soft-tissue healing, especially when a barrier membrane is placed under the intrasocket granulation tissue.

Bone quality is also of clinical concern in ensuring the proper primary stability of a dental implant. In the present cases, the tactile sense for the regenerated bone was soft, being similar to D3 quality bone on an empirical basis. However, implant stability was not jeopardized by undersized drilling.

The limitation of the present study is a lack of histology of the regenerated ridge and small numbers of the cases in the short term. This should be further investigated in future studies. Moreover, randomized clinical trials for comparison between the present protocol and the conventional ridge preservation procedure are warranted.

For managing a periodontally compromised tooth, the present flap approach using chronic intrasocket granulation tissue is a promising candidate modality. Further studies are needed to compare the effectiveness of the present protocol with that of other procedures.

Abbreviation

CBCT:

cone-beam computerized tomography

The authors declare no conflicts of interest.