Treatment of a two wall defect in a mandibular posterior tooth with autogenous bone graft obtained during ledge removal with a hand instrument.

Autogenous bone grafts have been considered the gold standard for bone grafting procedures. This case report describes the management of a two wall defect by utilizing the autogenous bone graft obtained during removal of ledges as a part of osteoplasty procedure. The bone was removed with a sickle scaler, and sufficient amounts of bone graft material were obtained to fill a two wall defect distal to left mandibular first molar.

INTRODUCTION

Periodontitis causes loss of tooth supporting bone. The bone loss may be vertical, horizontal, or combined. Regenerative periodontal therapy aims to predictably restore the structure and function of these lost tissues. For this purpose, various kinds of bone grafting materials have been used. These grafting materials are available in different forms. Among the graft materials, autogenous bone grafts have been considered the gold standard and can be harvested in either particulate or in the form of bone blocks.[1] With the advancement in techniques and materials used for regeneration, there has been a renewed interest in the use of autogenous bone grafts.

Sources of bone include bone from healing extraction wounds, bone from edentulous ridges, bone trephined from within the jaw, exostoses, and bone removed during osteoplasty and ostectomy.[2] Bone removed from the donor site during osteoplasty has the advantage of eliminating the need for additional donor site while accomplishing the objective of obtaining desirable bone contour in the surgical site. Traditionally rotary instruments have been used for this purpose. The obvious advantage of this technique is the ease of obtaining bone from already exposed surgical sites, but the disadvantages are its relatively low predictability and inability to procure adequate material for large defects.[2] In this case report, bone from ledges present on the mandibular posterior area was removed with the simple technique of scrapping with a sharp sickle scaler and the resulting graft was used to fill a two wall defect distal to first molar.

CASE REPORT

A 37-year-old male patient reported to the Department of Periodontology Government Dental College, Calicut with a chief complaint of bleeding from gums and bad breath of 3 months duration. On clinical examination, generalized moderate to deep periodontal pockets and bleeding on probing was noticed. Radiographic examination revealed generalized bone loss. Based on the history, clinical and radiographic findings, the patient was diagnosed with chronic generalized periodontitis. Six weeks after performing thorough scaling and root planning and following a strict plaque control regime, the case was reevaluated. Since the pocket depth was 7 mm distal to 36, it was decided to proceed with flap surgery [Figure 1].

Figure 1

Preoperative view

After giving block anesthesia in the left mandibular posterior area, internal bevel incision was given, and a full thickness flap was raised. Meticulous defect debridement and root planing was done to remove subgingival plaque, calculus, and inflammatory granulation tissue. A deep two wall defect was observed distal to first molar, heavy ledges were noticed extending bucally from second premolar to the second molar area [Figure 2]. First it was decided to remove the ledges as a part of osteoplasty procedure and then utilize the removed bone to fill the two wall defect. For this purpose, a sharp sickle scaler (PDT Cruise Scaler U15-33 R113, PDT Inc., US) [Figure 3] was used in a scrapping motion with sufficient force such that the bone was essentially shaved off [Figure 4]. The harvested bone was carefully collected in a dappen dish and then transferred to the defect with a periosteal elevator [Figures 5 and 6]. The flap was repositioned, single interrupted sutures were placed and periodontal dressing was given [Figures 7 and 8]. The patient was reviewed after 1-week, the healing was found to be uneventful. The sutures were removed, and the area was irrigated with saline. The patient was put on the maintenance phase with oral prophylaxis performed every 3 months. Radiographs were taken after 1-year. Clinically, there was a reduction in probing pocket depth from 7 mm to 3 mm [Figure 9]. Radiographs revealed radio opacity in the site distal to first molar, suggestive of bone fill in the defect [Figure 10].

Figure 2

Defect exposed, ledges seen

Figure 3

(a and b) PDT Cruise scaler U15-33 R113 used to remove ledge

Figure 4

After ledge removal

Figure 5

Autograft obtained from ledge removal with sickle scaler

Figure 6

Autogenous graft placed in the defect distal to first molar

Figure 7

Sutures placed

Figure 8

Periodontal dressing

Figure 9

Postoperative view after 1-year

Figure 10

(a) Preoperative radiograph, (b) Postoperative radiograph after 1-year

DISCUSSION

There is ample evidence that autogenous bone grafts shore up the formation of new attachment.[3] Autogenous bone, long considered the gold standard of grafting materials, is currently the only osteogenic graft available to clinical practitioners. Grafted autogenous bone heals into growing bone through the processes of osteogenesis, osteoinduction, and osteoconduction.[4] Moreover, auto-grafts are bioabsorbable, nonallergenic, easy to handle, and not costly. Rapid revascularization occurs around autogenous bone graft particles, and the graft can release growth and differentiation factors.

Autogenous bone blocks can be harvested from various extraoral as well as intraoral sites. Although iliac crest is one of the most preferred site, it is not always recommended due to its associated problems, such as postoperative infection; exfoliation and sequestration; varying rates of healing; root resorption and rapid recurrence of the defect, in addition to increased patient expense and patient morbidity.[5] Intramembranous (craniofacial origin) bones have been found to have more survival potential than endo-chondral (long bones) origin. Insulin-like growth factor-II and transforming growth factor-β have been found to be in a greater concentration in calvarial bone than in bone from the iliac crest or vertebral body.[6] This increase in concentration of growth factors leads to a greater capacity for bone repair and graft retention.

The use of intraoral graft material is, however, limited by the restricted donor sites in the oral cavity for extensive grafting. The use of bone removed from ledges as a part of osteoplasty procedure offers the added advantage of eliminating the nonphysiologic bony architecture. Ledges are plateau-like bone margins caused by resorption of thickened bony plates. The goal of osseous respective therapy is to reshape the marginal bone to resemble that of the alveolar process undamaged by periodontal disease. The reshaping process is an attempt to gradualize the bone sufficiently to allow soft tissue structures to follow the contour of the bone.[7] In this case, radicular blending was done using the sharp blade of scaler to gradualize the bone over the entire radicular surface providing a smooth, blended surface for good flap adaptation.

Many techniques and devices are available to harvest intraoral autogenous bone grafts, such as: Bone scraper, rotary instruments, bone chisels, rongeur pliers and piezoelectric devices. Particulate graft material is easy to procure and is best suited for two, three, or more walled defect, as they usually provide adequate space for placing and retaining the bone graft material for a sufficient period. The commonly used technique to procure particulate grafts is the use of carbide bur at speeds between 5000 and 30,000 rpm. The inability to procure adequate material for large defects is a major disadvantage of using rotary instruments.[2] Conventional osteotomy or milling procedures has some limitations like overheating of the bone when water cooling is insufficient, which leads to possible structural bone changes on living cells.[8] A simple technique for removal of bone using a sharp sickle was done, in this case, which turned out to be effective means for harvesting sufficient amounts of bone graft. Although specialized bone scrapers have been used for obtaining grafts from intraoral sites before.[910] To the best of our knowledge, there are no previous reports of bone harvesting done with scaler alone.

Studies regarding cell viability with different harvesting instruments have showed different results. Chiriac et al. reported higher percentages of cultured osteoblast cells for both rotary drill and the piezoelectric device, 88.9% and 87.9%, respectively.[11] They concluded that the harvesting methods are not different concerning the detrimental effect on the viability. Another study by Bacci et al. showed contradictory results, their histological findings revealed that smaller particle size bone chips, obtained with a piezoelectric device, had less vital bone (64.83%) compared with the small particle size bone chips harvested with a bone scraper (75.34%).[12]

In this case, sufficient amounts of autogenous particulate bone were obtained during the ledge removal process to fill the two wall defect distal to first molar. No specialized one scrapping instrument was used. Instead the sharp blade of the sickle scaler was utilized, which was also less time consuming.

Autogenous grafts have long remained and will continue to remain as the first preference for bone grafting procedures because of its superior biologic properties. Ledges are frequently found in posterior regions and if properly managed can act as a source of autogenous graft. Routinely used scaling instruments may be utilized in certain situations instead of using specialized bone scrapping instrument.