Tooth roots may become perforated during different stages of endodontic treatment, especially cleaning and shaping¹ and this leads to communication between the root canal and the outer surface of the tooth.² Perforation can occur at the apical, middle, or cervical root sites, and depending on the site of the perforation, treatment approach and prognosis can vary.¹ Prognosis may also be affected by the time between the incident and treatment, as well as the size of perforation. When minimal time has passed, and there is minor destruction, the perforation has a better prognosis,³ although this is based on literature predating calcium-silicate-based materials.

Strip perforation is a type of root perforation occurring in the coronal third of the root canal near the furcation area due to misadventure in access preparation and inappropriate use of instruments such as Gates-Glidden burs.¹,⁴ This perforation occurs on curved roots such as mesial roots of mandibular molars.⁵ A major challenge in endodontics is repairing a strip perforation because it is usually inaccessible and may have a poor prognosis due to having an oval shape, thin margins, and proximity to the gingival sulcus.¹,⁵

Perforations must be sealed with an appropriate repair material.² This material must have specific properties including good sealing ability, biocompatibility, radiopacity, nontoxicity, noncarcinogenicity, and moisture tolerance.⁶ It should also be easy to place, as well as have the ability to promote osteogenesis and cementogenesis.⁶ Historically, different materials have been used to repair perforations, for example, amalgam,⁷,⁸ glass ionomer cements,⁸ and cavit.⁷ More recently, calcium silicate-based materials have been used such as mineral trioxide aggregate (MTA),⁹ Biodentine,¹⁰ and Bioaggregate.¹¹

Cold ceramic (Monsefteb, Yazd, Iran) is another MTA-like bio-ceramic material that has been introduced into endodontics as a root-end filling material.¹² Its main components include calcium oxide (48.12%), barium oxide (18.61%), silicon dioxide (16.19%), sulfur trioxide (10.15%), as well as trace amounts magnesium oxide, manganese (II) oxide, iron (III) oxide, sodium oxide, potassium oxide, and titanium dioxide. In the presence of moisture, cold ceramic sets initially within 15 min and reaches complete set within 24 h.¹² The sealing ability of this material has been reported to be better than a glass ionomer cement (Master-dent, Dentonics Inc., USA) and amalgam¹³,¹⁴ cold ceramic is also biocompatible and nontoxic,¹⁵,¹⁶ and has appropriate radiopacity.¹⁷ This case report describes a mandibular molar with iatrogenic strip-perforation that was successfully managed using cold ceramic.

A 39-year-old male was referred from his general dentist in December 2015 with a strip-perforation of the mesiolingual canal of the lower left first molar. The original root canal treatment had been completed some 2 years earlier by another dentist, and his current dentist had attempted retreatment but was unable to because of the strip-perforation. After patient examination, patient consent form was obtained. The patient's medical history was nonsignificant, and extra-oral evaluation revealed normal soft tissues. On oral examination, the tooth exhibited no mobility or probing defects. The tooth was exquisitely tender to percussion, had no caries, and had been temporarily restored with Cavit. Radiographic evaluation of the referrer's preoperative radiograph, which was provided by the patient revealed a periapical lesion and bone loss mostly around the distal root and in the furcation area, and also slight periodontal ligament widening around the mesial root as well as a likely strip-perforation Figure 1. Treatment options such as perforation repair and extraction/prosthetic replacement or extraction/implant were discussed with the patient, and he chose the perforation repair to retain the tooth.Figure 1

Referrer's preoperative radiograph (December 2015).

Strip-perforation is an endodontic incident that may happen unexpectedly, and influence the prognosis of the tooth. Strip-perforations are created mostly in curved roots, especially in mandibular mesial roots due to over-instrumentation and excessively tapering preparations.¹⁸ This procedural complication will usually lead to a lesion and bone resorption at the perforation site as a result of microbial leakage or incompatible repair material extrusion.¹⁸ Over time, the lesion may enlarge, with time and perforation size acting as determinative factors for the dentist in predicting treatment outcomes for the patient.³ In this case, some 2 years had elapsed from the creation of the strip perforation, and so the prognosis was unfavorable as based on the literature. However, the properties of cold ceramic include excellent sealing ability, biocompatibility, nontoxicity, noncarcinogenicity, radiopacity, easy handling, and minimal adverse impact on hard tissue.¹³,¹⁴,¹⁵,¹⁶,¹⁷,¹⁹ Hence, as an MTA-like material, cold ceramic was used as both the root filling material and the perforation repair material in this case. Many materials have been used for this purpose but have failed due to a lack of sealing ability or questionable biocompatibility. Therefore, new materials have been suggested for perforation repairs such as MTA, Biodentine and other bio-ceramic materials, because of their better properties and acceptable clinical results.⁶ Good sealing ability can be achieved by using MTA, but a potential problem is its long setting time that may allow microbial leakage. The initial setting time of 15 min for cold ceramic may therefore improve the prognosis during the first 24 h.²⁰ Furthermore, the handling of MTA can be challenging and takes time and practice, whereas cold ceramic is easily controlled in such sites.²⁰

The goal of a perforation repair is to mechanically and biologically seal the communication between the periradicular tissues and the access cavity space, using a biocompatible material that promotes a favorable tissue healing response.²¹ In the present case, the postoperative radiograph showed that this had been achieved, although there was some extrusion of the material into the tissues. However, cold ceramic has been shown to have minimum adverse effects on hard tissue¹⁹ and this was confirmed in this case. Nevertheless, further studies are recommended in this area.

In conclusion, successful perforation repair requires a good coronal seal, bone regeneration, and resolution of signs and symptoms of infection, all of which were attained in this case.

Financial support and sponsorship

Nil.

Conflicts of interest

Dr modaresi is the owner of cold ceramic material. Other researchers have also done studies on this material.