Use of a Resin-Based Root Canal Sealer Followed by Apicoectomy on Two Teeth

The major objectives of endodontic treatment are cleaning, shaping, disinfection, and obturation of the root canal space. Gutta-percha and a sealer used with various techniques are considered the standard in root canal obturation. Among the commercially available endodontic sealers to date, the most widely used are zinc oxide eugenol and resin-based sealers. The former has been shown to exhibit strong adhesion to gutta-percha, while the latter exhibits favorable adhesive properties toward root canal dentin.¹ Ideally, a sealer should have adhesive properties to root canal dentin as well as to gutta-percha. Furthermore, this material should be biocompatible and easy to manipulate.
EndoREZ (ER [Ultradent Products]) is a recently introduced resin-based root canal sealer in which urethane dimethacrylate (UDMA) is the most important component (Figure 1). One of its prime properties is hydrophilicity, allowing penetration of the material into the dentinal tubules.² In addition, it exhibits a radiopacity similar to gutta-percha, and it is compatible when bonding techniques are used. ER is used to seal root canals in conjunction with one or more gutta-percha cones either without using a condensation technique or with traditional condensation filling techniques. It has been demonstrated that ER has good biocompatibility when tested in soft and hard tissues in animals.^3-5 Independent cytotoxicity tests⁶ have confirmed the above-reported findings.
In a clinical study conducted over 24 months, 145 endodontic cases were evaluated in patients that had a single-appointment endodontic treatment in which roots were filled with ER and gutta-percha using lateral condensation. The authors reported a success rate of 91%.⁷ To date there is no further information on the performance of this resin-based sealer that has been placed in vivo.
This article presents a case report involving 4 teeth treated with ER and a single gutta-percha cone, two of which were scheduled for apical endodontic surgery due to the presence of an extensive periapical lesion. This case differs from the usual treatment in that after resecting the roots no retrograde filling was placed.

CASE REPORT

Figure 1. EndoREZ.	Figure 2. Pretreatment panoramic radiograph. An extensive periapical lesion in the area of teeth Nos. 8, 9, 10, 11, and 12 is present.

A 26-year-old male was seen at the Department of Oral and Maxillo-Facial Surgery at a local public hospital for an extensive symptomatic lesion involving two thirds of the left maxilla.
The surgeons decided that the lesion, due to its dimensions, should be surgically removed and biopsied (according to the protocols of the Maxillo-Facial Surgery Clinic). The patient was then referred to the Endodontic Clinic of the Dental School at the University of Cagliari, Italy, to have endodontic treatment done to the teeth involved within the lesion (which would not respond to vitality tests) prior to surgery.
The patient presented with complaints of pain in the left upper arch; radiographic examination demonstrated the presence of an extensive periradicular lesion. The lesion involved the bone of the left maxilla and comprised the area between the distal surface of tooth No. 8 and the mesial surface of tooth No. 13 (Figure 2). Clinical examination revealed the lesion to be mildly symptomatic in spite of the presence of a significant swelling in the left maxillary area. Tooth No. 9 had been treated endodontically approximately 10 years previously and was suspected to be the cause of the lesion (Figure 2). The tooth was sensitive to percussion and palpation.
Teeth Nos. 10 to 12 were nonresponsive to vitality tests and also sensitive to percussion and palpation. It was decided that tooth No. 9  needed retreatment and teeth Nos. 10 to 12 needed endodontic treatment prior to surgery. The retreatment of tooth No. 9 was completed in 2 appointments due to the considerable drainage that occurred after opening the access cavity, removing the previous filling material using Endosolv E (Ogna Pharmaceuticals, Milan, Italy), and retreating the root canal. A calcium hydroxide intermediate medication was placed, and the treatment was completed one week later. All the endodontic treatments were then completed as follows.
After preparation of the access cavities, the teeth were instrumented using the Anatomic Endodontic Technology (AET) system (Ultradent Products).8 Irrigation was accomplished using 5% NaOCl followed by EDTA 18% (Ultradent Products) with a final rinse of sterile saline. The canals were dried using capillary tips and paper points, and the roots were filled with a single gutta-percha cone, which exhibited tugback at the working length. ER was used as a sealer, adhering to the technique specified by the manufacturer. The access cavities were temporized with Cavit G (3M ESPE). Permanent restorations using composite resin and bonding agent were placed within one week following endodontic treatment.
Two weeks after completion of the final restorations the patient was scheduled for surgery. Prior to surgery it was recommended to the maxillo-facial surgeons to perform apicoectomies on teeth Nos. 9 and 10 without placing a retrograde filling in the resected roots. The patient agreed to this treatment and signed an informed consent form.

Figure 3a. The lesion was removed as well as the 2 apices of teeth Nos. 9 and 10.	Figure 3b. Radiograph of the completed root resections.

Under general anesthesia the lesion was removed and apicoectomies were performed on teeth Nos. 9 and 10 (Figure 3a). Approximately 3 mm of each root was removed using a high-speed fissure bur under continuous water cooling. Subsequently, the gutta-percha was burnished at the resected interface using a round burnisher (Figure 3b). The patient tolerated the surgical treatment well.
The first clinical recall of the patient was done one month after suture removal, and clinical examination revealed good tissue response. The patient reported being symptom-free.
Six months later the patient was still without symptoms, and a panoramic radiograph showed a considerable reduction in the size of the lesion (Figure 4).

Figure 4. Panoramic radiograph showing the lesion considerably reduced 6 months after treatment.	Figure 5. Intraoral radiograph of teeth Nos. 9 and 10 taken 12 months after treatment demonstrates good bone healing.

At the 12-month recall the patient was symptom-free; clinical examination revealed absence of swelling and no sensitivity to percussion of the teeth or palpation of the area.
The panoramic radiograph showed extensive bone repair, and in particular the intraoral radiograph of teeth Nos. 9 and 10 demonstrated healing of the lesion (when compared with the radiograph in Figure 3b), with good bone fill in the resected area and a close adaptation of the bone to the resected roots (Figure 5).

DISCUSSION

The principles of hydrophilic methacrylate resin sealers are based on the same theory as dentin bonding systems that are used in restorative dentistry for resin composite restorations and other applications. EndoREZ is a relatively new UDMA-based resin sealer to be used with a single gutta-percha cone for filling of endodontically prepared root canals.
The present report is a first in the observation of 2 roots treated with ER and a single cone, performed in vivo, where no retrograde fillings were placed in the resected roots. The choice of not using a retrograde filling material on the resected roots of teeth Nos. 9 and 10 was made to observe the clinical behavior of the new root filling system in an extreme condition. This choice was made possible in this specific case because the indication for apical surgery was not absolute,9 but was dictated by the routine procedures adopted in the Maxillo-Facial Surgery Clinic.
The clinical demands of the root canal treatments in this case were complex, as tooth No. 9 was a retreatment case with an apex that was both resorbed and over-instrumented, while teeth Nos. 9 and 10 were surrounded by an extensive periapical lesion. In addition, considerable drainage was present at the time of root canal treatment of tooth No. 9.
As specified previously, teeth Nos. 11 and 12 were endodontically treated using the same system, and a good degree of healing of the lesion could be noted in the panoramic radiograph taken 6 months after treatment (Figure 4).
This clinical result is consistent with the good success rate reported by other authors in a 24-month clinical follow-up on 145 endodontic cases. These patients had a single-appointment endodontic treatment in which the roots were filled with ER and gutta-percha using lateral condensation.⁷
In a recently published  study using SEM and transmission electron microscopy it was observed that the junction between the ER and the intraradicular dentin was often intact and exhibited the presence of a thin hybrid layer as well as the presence of sealer tags. There were also areas that displayed a gap in which the sealer/dentin interface could be observed.10 These findings are consistent with what has been reported here, in that the sealer was present along the dentinal walls, with the presence of resin tags at the interface in the areas where separation was seen.

CONCLUSIONS

The clinical and radiographic observations up to 12 months point to a successful treatment and lend support to a technique that offers a viable treatment option, particularly since no retrograde fillings were placed in the resected roots. It is recognized that the sample size is very small and that no conclusions can be drawn. Therefore, this article should be considered a case report and not a research study.

References

Dr. Cotti received her DDS from the University of Cagliari, Italy, in 1985; received a certificate in endodontics from the University of Loma Linda- California in June 1990; and received a master of science in endodontics from the University of Loma Linda-California in 1991. She is the chairman of the Department of Conservative Dentistry and Endodontics at the School of Dentistry, University of Cagliari, Italy. She is teaching in the Advanced Education Programs in Endodontics at the University of Bologna and at the University of Roma (La Sapienza). Dr. Cotti also works in private practice limited to endodontics. She is the author of several papers in the field of endodontics and has a specific interest in clinical research on periapical pathology and imaging techniques. She can be reached at cottiend@tin.it.

Dr. Sergi received his DDS from the University of Cagliari, Italy, in 2001. He practices general dentistry in Cagliari and endodontics in the Department of Conservative Dentistry and Endodontics at the University of Cagliari. He can be reached at cosergi@tiscali.it.

Dr. Bassareo received his DDS from the University of Cagliari, Italy, in 2000. He practices general dentistry in Cagliari and endodontics in the Department of Conservative Dentistry and Endodontics at the University of Cagliari. He can be reached at abassareo@virgilio.it.

Disclosure: The authors do not have any financial interest in products or companies mentioned in the article.