Case Report: Introduction of antibiotic releasing calcium sulfate bone void filler beads (Stimulan) for management of an infected cyst of the maxilla

Introduction

Inflammatory odontogenic cysts of the maxilla and mandible are located in the alveolar region of the jaw. They are most commonly a radicular cyst involving an offending tooth with a well-defined radiolucency on a radiograph.¹ It is usually associated with a necrotic pulp and the prevalence ranges from 7% to 54% of all jaw cysts in permanent dentition.² With the advancement in bone tissue engineering, there have been many potential alternatives to the traditional use of bone grafts with major benefits like vast availability and no cross reactions. For an ideal alloplastic material, calcium sulfate has characteristics of bone regeneration and is additionally an excellent osteoinductive and osteoconductive material for bone defect reconstruction.³ The following case represents the successful management of a radicular cyst, which includes endodontic treatment and cyst enucleation, chemical cauterization followed by introduction of antibiotic (Vancomycin) releasing calcium sulfate filler beads into the defect.

Case report

A 35-year-old male patient was referred to the Department of Conservative Dentistry and Endodontics of Sharad Pawar Dental College in the month of March 2023, for the management of a lesion related to the upper right anterior maxilla. The patient had a main complaint of swelling over the right side of the upper jaw for the previous four months. On clinical examination, there was a single localized swelling, measuring 3 × 3 cm on his hard palate with serous discharge, which was endodontically removed through root canal openings of his central and lateral incisor of the right side (Figure 1). The dental records uncovered a history of injury two years before, over the upper anterior tooth region. The maxillary right central incisor was discolored with no mobility (Figure 2). On palpation, the swelling was soft and non-tender. A yellow-colored serous exudate was aspirated upon accessing the pulp chamber, which eventually reduced the swelling over the palate. A unilocular radiolucency with a well-defined radiopaque border was seen on radiographic examination (Figure 3). Taking into account the age of the patient, both involved teeth were endodontically treated. Careful enucleation, curettage, and chemical cauterization of the right anterior maxillary area was carried out followed by introduction of antibiotic (Vancomycin) releasing calcium sulfate bone void filler (Stimulan®) as a graft material.

Figure 1. Localized swelling over right anterior hard palate.

Figure 2. Discolored right central incisor.

Figure 3. Pre-operative occlusal radiograph.

Surgery

Under all aseptic protocols, the patient was prepared for the surgical procedure under local anesthesia. A crevicular incision was made over the right first premolar to the left central incisor to expose the underlying bone. The buccal bone was found to be paper thin making it easier for enucleation. After enucleation a specimen was sent for histopathological examination. Thorough curettage was performed followed by chemical cauterization using carnoy solution (Figure 4). Apical plugging over the upper right central and lateral incisor was done with mineral trioxide aggregate (MTA). To fill the maxillary defect, calcium sulphate beads were utilized. They are available commercially as the Stimulan® Rapid Cure kit (Catlog number- 620-005, supplied by Biocomposites, England) containing 5 cc of calcium sulphate hemihydrate powder. Then 500 mg of vancomycin powder was mixed with it in a mixing bowl. When a ‘doughy’ stage was achieved the mixture was poured into the mould and allowed to set for 15 minutes. In the meantime, the cystic cavity was dried and beads were used to pack the whole defect. Closure was done using absorbable sutures. Postoperatively, the patient was prescribed antibiotics, Augmentin tablets 625 mg, twice daily for five days and Aceclofenac tablets 100 mg + serratiopeptidase 15 mg + paracetamol 325 mg, twice daily for five days. He was advised to maintain good oral hygiene and kept on regular follow–up. The follow-up after one month showed no signs of active inflammation or symptoms (Figure 5). The patient was satisfied with the treatment.

Figure 4. Maxillary cavity after enucleation and chemical cauterization.

Figure 5. Follow-up occlusal radiograph.

Discussion

Radicular cysts are the most common odontogenic cyst arising from epithelial cell rests of Malassez in the periodontal ligament and proliferate peripherally as a result of inflammation caused by infection at the root apices. When infected, they become symptomatic since they slowly grow, displace all associated teeth and may lead to mobility and root resorption.⁴ This results in swelling, pain and the patient becomes conscious of the problem. In our case, there was no tooth mobility, no root resorption but displaced roots were seen.

Conventionally, a radicular cyst is treated with an endodontic approach, combined with surgical enucleation or decompression and in adjuvant with extracting the offending tooth. An endodontic approach with radicular cysts will eradicate all the microbes or reduce the microbial load substantially from the root canal and reinfection is prevented by Retrograde filling.⁵ Those lesions, which fail to respond with this modality, can be managed successfully by curettage of the epithelial lining in the apical region and extraction of the associated teeth. The other recommended options are decompression of the cyst surgically, to decrease the size before marsupilisation or complete enucleation is done in order to reduce the risk of damage to adjacent anatomic structures.⁶

Depending on the location and size of the bone defect, numerous grafts can be used for reconstruction. Use of autogenous bone grafts are considered as a gold standard method of such defects. Allogenic materials on the other hand have a risk of viral transfer with cross infections. The same limitation is present with xenografts which are generated from a genetically different species. Alloplasts are synthetic graft materials that have characteristics of osteoinduction and osteoconduction and hence they are more popular. Some examples of alloplastic grafts are glass ionomers, bioactive glass, calcium phosphates, calcium sulfate, tricalcium phosphate and synthetic hydroxyapatite.⁷ The limitations of these autografts, allografts and xenografts, give rise to an increase in the demand for a bone graft substitute. Alloplasts initiate the process of bone formation through ‘creeping substitution’, a phenomenon in which the process of osteoconduction with subsequent migration of osteoblastic cells and blood vessels from adjacent healthy bone to the scaffold takes place. Calcium sulfate as a bone graft substitute plays the role of a filler material in managing dead space due to its properties of biodegradability and biocompatibility. It does not cause cross reactions and it is resorbed rapidly within 1–3 months by creating porosities for bone ingrowth. The introduction of locally releasing antibiotics from calcium sulfate beads offers significant benefit in the management of an infected surgical site. In a study, vancomycin was found to cause a six times reduction in microbial growth by seven days that illustrated its importance with prolonged release in high concentrations when treating biofilms.⁸

The calcium sulfate beads are radiopaque and hence are easily evaluated on plain radiographs for assessing the extent of the defect and revealing the status of the cortical plates and the relationship with the adjacent tissues. Sequential radiographic analysis is needed for studying spontaneous bone formation.⁹ There is a paucity of literature on using antibiotic releasing bone substitutes in the case of a radicular cyst. Hence, the introduction of calcium sulfate bone void fillers with antibiotics can be a beneficial and newer modality for management of infected maxillary cysts in young adults.

The utility of antibiotics impregnated in calcium sulfate beads are not limited to the treatment of infected cysts of the jaw, they are also being used for the treatment of diabetic foot infections and chronic osteomyelitis of the long bones and joints. Studies have shown 80% wound healing and 100% graft preservation with no recurrent infections observed and no requirement for amputation during follow-up.¹⁰ These results of high healing rates have been successfully recorded in the studies and could explain the eradication of residual microorganisms with the delivery of a high concentration of antibiotics directly to the wound.¹¹

To summarize, the use of antibiotic releasing calcium sulfate beads is an acceptable method of treating an infected cystic cavity. In the presented case, the follow-up has shown satisfactory results with no signs of re-infection. Future studies should be conducted to assess use of other antibiotics as well as their concentration in larger samples or clinical trials. The response of combining bone graft substitutes with antibiotics in vivo, comparing bone regeneration, and wound healing with each material with or without antibiotic is to be determined.

Consent

Written informed consent for publication of their clinical details and clinical images was obtained from the patient.