Transurgical Restoration With Glass-Ionomer Cement As an Option for Root Perforations: Case Report

During endodontic treatment, complications, including accidents by clinicians, may occur. Among these are perforations of the walls of the canal or of the floor of the pulp chamber, leading to a communication with the adjacent periodontium. This situation affects the prognosis of endodontic treatment, with perforation localization being a crucial factor.^1,2 Thus, furcation perforation may present an unfavorable prognosis,³ as may cervical perforations at the level of the bone crest. This is attributed to bacterial contamination of the oral microbiota along the gingival sulcus, delaying the repair process.²

Numerous materials have been used to seal perforations.⁴ The sealing must be attained between the tooth structure and the periodontium, depending on the location and size of the perforation, surgical technique, and physico-chemical characteristics of the material used to seal the communication.³ Materials ideal for this use are those that are biocompatible, exhibit good sealability and antibacterial effects, have short preparation time, are nontoxic, non-absorbable, radiopaque, and able to induce bone formation.^3,4 Materials used for this purpose have included amalgam, zinc-engenol oxide-based materials, calcium hydroxide, glass-ionomer cement (GIC), mineral trioxide aggregate (MTA), super-ethoxy benzoic acid (EBA), and others.^4,5 GIC has been used in the repair of perforations during endodontic treatment due to its capacity to provide adhesion to dentin; unlike other materials, it demonstrates good sealing ability.^1,2

Developed in the late 1960s, GIC is a biointeractive adhesive hybrid restorative material with therapeutic action that binds to dentin and liberates fluoride, thus assisting in remineralization and biocompatibility, although it does not produce hydroxyapatite.^6,7 While the dentin bonding property of GIC is due to its fluidity and higher coefficient of thermal expansion,⁸ which promotes good marginal sealing, less microleakage, and a high retention rate, its adhesive properties are due to the ability of the glass ionomer in its acidic phase to chemically chelate calcium and establish a chemical bond with dentin and enamel.⁷

Despite these attributes, conventional GIC has several clinical limitations, including preparation time, initial dehydration, and rough surface texture. In the early 1990s, the introduction of modified GIC by photopolymerizable resin, containing monomer and a photoinitiator in addition to polyacrylic acid, aimed to overcome the deficiencies of conventional GIC, presenting longer working time and improved appearance and translucency.^7,8

This article, through a clinical case, illustrates the treatment of a root perforation using GIC as the sealing material.

A 37-year-old systemically healthy, nonsmoking female patient presented to the Department of Periodontics and Endodontics of the Piracicaba Dentistry Faculty, reporting suppuration in the anterior region of the upper left central incisor (tooth No. 9). Radiographic examination showed satisfactory obturation of the root canal and no abnormality (Figure 1). Clinical examination included periodontal consultation, which revealed a probing depth of 11 mm on the vestibular aspect, with bleeding and suppuration (Figure 2).

At the next visit periodontal surgery was performed under local anesthesia using 2% xylocaine hydrochloride with adrenaline (1:80,000). Under anesthesia by infiltration, gingival detachment was performed by full-thickness flap for total exposure of the region, allowing visualization of the bone defect and root perforation (Figure 3). The root perforation was observed to have necrotic tissue, which was removed with the aid of periodontal curettes (Figure 4). Then, self-curing GIC (Maxxion R, FGM, fgm.ind.br) was inserted into the perforation to seal the site (Figure 5). Suturing was performed with internal vertical bedstead to maintain the integrity of the endodontic treatment.

Written postoperative instructions were given to the patient, and analgesic (ibuprofen 400 mg three times daily) was prescribed for 3 days. Antibiotic (amoxycillin 500 mg three times daily) was prescribed for 7 days, and the patient was told to use 0.2% chlorhexidine mouthrinse for 10 days.

Sutures were removed 10 days after the surgical procedure, and a periodontal control was performed. The patient was instructed to maintain meticulous oral hygiene and was recalled initially every 8 weeks for 6 months, and then every 3 months.

After 2 months of healing, no clinical changes were observed. However, 6 months after the surgical intervention during a periodontal probing procedure, bleeding and suppuration were evident, and, therefore, reintervention was indicated (Figure 6). The characteristics of the glass-ionomer compositions are particularly important because rough surfaces, due to the deterioration of conventional moisture-sensitive GIC, are more prone to bacterial colonization and plaque maturation, thereby increasing the risk of intervention. Thus resin-modified GIC, which contains polymerizable organic monomers, offered improved mechanical properties and surface smoothness in this case.

During the reintervention, the self-curing GIC was replaced with a light-curing GIC (Vitremer^™, 3M Oral Care, 3m.com) (Figure 7). At the 2-year follow-up, the clinical and radiographic outcomes were satisfactory (Figure 8). The probing depth, which was >5 mm before the reintervention, was reduced to 2.64 mm; thus, it was concluded that the evaluated treatment was effective in providing insertion gain. Because the patient had a low smile line, the anterior esthetics were acceptable to her despite some discoloration gingivally and on the facial surface of the tooth; moreover, the treatment returned the function of the tooth to the stomatognathic system.

Perforations of the root may occur accidentally during root canal treatment. Such perforations result in the formation of granulation tissue as a chronic inflammatory reaction of the periodontium that may lead to irreversible loss of either attachment or tooth. A good prognosis can be expected in cases of fresh, small, coronal, and apical perforations. When left untreated, perforations in the cervical third of the root have the worst prognoses.⁹

Bacterial infection may occur because of the perforation, which could lead to gingival downgrowth of epithelium into the perforation area, inflammation, bone resorption, and/or necrosis and eventual loss of the tooth.¹⁰ Repair of a perforation without periradicular inflammation is possible, provided infection is avoided and asepsis is maintained during treatment.¹¹

Treatment of these perforations may be conducted either surgically or nonsurgically, depending on the case. The nonsurgical coronal approach involves the immediate placement of a repair material in the perforation to avoid potential bacterial infection of the wound site.¹² The primary difficulty with conventional repair procedures is the extrusion of the filling material into the periodontal space and interference with periodontal reattachment.¹³

The ideal material used for perforation sealing should promote regeneration of periradicular tissues, as it should have antimicrobial activity. It should prevent leakage of microorganisms and their by-products. It should also be dimensionally stable, radiopaque, insensitive to moisture, adhesive to dentin, nontoxic, nonirritant, non-carcinogenic, and biocompatible, and promote osteogenesis and cementogenesis.¹⁴ GICs have received particular attention as a perforation repair material. Light-cured GIC is a hybrid bioactive adhesive restorative material that bonds to dentin and releases fluoride, helping remineralization and biocompatibility.²

In the present clinical case, GIC was chosen because of its various advantages such as chemical adhesion to tooth structure, excellent biocompatibility, and anticariogenicity. It also has demonstrated good sealing ability.¹ The advent of light-cured glass ionomer, which is less sensitive to moisture, served as an alternative to conventional GIC for not only restorative purposes, but also for sealing perforations. Apart from the ability of light-cure GIC to command set, bond to dentin, and release fluoride, it also is biocompatible like conventional GIC.²

GIC was found to be superior compared with composite resin, amalgam, and a temporary dental restorative material when used in perforation repair in previous studies. In one study MTA cement and GICs did not show statistically significantly different results. MTA provides an effective seal of root perforations and shows promise in improving the prognosis of perforated teeth that would otherwise be compromised.¹⁴ Also, the results indicated that there is a potential antibacterial effect of the material, which may have killed bacteria that were penetrating close to the material surface and administering surface protection, although MTA did not improve microhardness or sealing.¹⁵

Based on obtained clinical success, perforation repair should result in formation of new bone and cementum, as observed in the present clinical case. Previous studies revealed that cementogenesis surrounding the perforation repair biomaterial is ideal. Formed cementum is a biologic barrier against the spread of microbial irritants within the root canal system. Case studies regarding the perforation repair using GIC in permanent teeth have showed that this biomaterial is capable of complete regeneration of adjacent dentoalveolar tissues and is a suitable option for repairing perforations.

Lucas Alves Moura, DDS, PhD
School of Dentistry, Integrated Faculty Brazil-Amazonia (FIBRA), Belém-PA, Brasil

Kalena de Melo Maranhão, DDS, MSc
Post Graduate Student, School Mauricio of Nassau (UNINASSAU), Belém-PA, Brasil

Ana Cássia de Souza Reis, DDS, MSc
Post Graduate Student, School of Dentistry, School Superior of Amazonia (ESAMAZ), Belém-PA, Brasil