Successful removal of a 16 mm long pulp stone using ultrasonic tips from maxillary left first molar and its endodontic management

Abstract

To present a case report describing successful removal of a 16 mm long pulp stone in a single mass from a maxillary left first molar and its endodontic management. In the presented case, the conventional approach of dissecting the pulp stone was not considered, as radiographically the calcification was extending up to the apex of the palatal root canal and the separation of the coronal and radicular pulp stone would have risked the obliteration of its orifice. A new set of ultrasonic endodontic tips were used for the removal of significantly large pulp stone in single mass.

INTRODUCTION

The presented case report describing successful removal of a 16 mm long pulp stone in a single mass from a maxillary left first molar and its endodontic management. A new set of ultrasonic endodontic tips were used for the removal of significantly large pulp stone in single mass. Removal of such a large pulp stone in a single mass has never been reported in the literature.

A variety of changes occur both in the hard and soft tissues of the teeth with ageing. Bernick and Nedelman[1] stated that there is an increase in number of vascular and neural sheaths of old pulps which are the foci of calcification. The persistence of the connective tissue sheaths of nerves and blood vessels gives the pulp histologically fibrotic appearance. There is up to half decrease in cell density of fibroblasts, odontoblasts, and mesenchymal cells from 20 to 70 years.[2] When tooth wear, caries, or operative intervention is a feature; the deposition of secondary and tertiary dentin becomes more evident.[1]

These mineralizations in the dental pulp are apparent in more than half the teeth of the young and they increase in the elderly. These mineralizations sometimes can be so extensive that the entire root canal system is obliterated. As a result, the root canal treatment can become difficult if not an impossible task.[3]

Pulp stones are aggregations of calcium phosphate, calcium carbonate, and magnesium phosphate formed in the pulp chamber or the root canals and may be attached to the dentinal wall or lie freely within the pulp. Shafer et al.,[4] classified pulp stones into true denticles, which resemble dentine because of their tubular structure; and false denticles, which are composed of localized masses of calcified material and do not show dentinal tubules. Cook[5] stated that pulp stones can be found in normal teeth with healthy pulps as well as in carious teeth and periodontally involved teeth. Bergman[6] however, stated that stones occur mainly in teeth with pathologic pulps where the pulp is dead or dying. Cook[5] and Bergman[6] reported that pulp stones may cause discomfort and pain, though they may be present sometimes without any clinical symptom.

CASE REPORT

A 40-year-old female reported to the department of conservative dentistry, with a chief complaint of food impaction and pain in the left upper molar region. The pain started a month ago and was dull, gnawing in nature with moderate intensity. She reported to the clinic only when the pain became severe. On clinical examination, it was observed that the maxillary left first molar had a deep occlusal caries with an exposed pulp. The tooth was severely tender on percussion and had moderate pain on palpation. Pulp testing with electric pulp tester (Parkell Inc. Edgewood, NY, USA) and thermal test using hot gutta percha elicited non-responsiveness from the suspect tooth, intraoral periapical (IOPA) radiograph revealed diffused radio-opacities throughout the pulp chamber and in the palatal root canal. The canal outlines for the mesiobuccal and distobuccal roots were quite clear and traceable till the apex [Figure 1a].

Figure 1.

(a) Preoperative radiograph showing diffused radio opacities throughout the pulp chamber and in the palatal root canal. (b) Start X™ # 3 ultrasonic tip for calcified canal scouting. (c) Photograph of partially calcified pulp tissue. (d) Length of the partially calcified pulp tissue was measured to be 16 mm long. (e) Working length radiograph (f) Post-obturation radiograph. (g) Follow-up radiograph after 6 months. (h) Fixed pulp stone was embedded in paraffin wax for histopathological evaluation. (i) Photomicrograph showing dystrophic calcifications

By evaluating the tooth clinically and radiographically, a diagnosis of pulpal necrosis with acute apical periodontitis was made and an endodontic approach was planned for this tooth.

Access was gained to the pulp chamber after administration of local anesthesia (2% lignocaine with 1:100,000 epinephrine) under rubber dam isolation. No drop was felt in the pulp chamber since it was completely obliterated. The calcified mass was clinically visible as an irregular translucent mass attached to the walls and the floor of the pulp chamber. After careful extensions of the access cavity, an ultrasonic nonactive tip with active lateral part Start-X™ #1 (Dentsply Maillefer) was introduced with a Piezo ultrasonic generator (EMS MINIPIEZON) for further refinement of access cavity walls and displacement of the calcified mass. An ultrasonic tapered and active tip Start-X™ #3 (Dentsply Maillefer) [Figure 1b] was introduced to remove the calcific obstruction. The entire mass could be dislodged from the walls of the pulp chamber and its underlying attachment. The calcified mass thus removed, had its extension into the palatal root canal that traversed along its entire length [Figure 1c]. The length of calcified tissue was measured to be 16 mm long [Figure 1d]. The shape of the calcified mass confirmed to the shape of pulp chamber and palatal root canal.

After locating the root canal orifices, the patency of all the three root canals was checked with #10 K file (Kerr USA). The working length was determined by Root ZX II (J. Morita, Kyoto, Japan) apex locator for all the three root canals and confirmed by a radiograph [Figure 1e]. The root canals were cleaned and shaped by rotary nickel-titanium ProTaper instruments (Dentsply Maillefer) using Glyde (Dentsply Maillefer) as a lubricant. The canals were sequentially irrigated using 5.2% sodium hypochlorite and 17% ethylenediaminetetraacetic acid (EDTA) during the cleaning and shaping procedure. The canals were thoroughly dried and all the root canals were coated with AH-plus resin based sealer (Dentsply Maillefer). Obturation was carried out using the ProTaper gutta percha point. The access cavity was restored with posterior composite resin (Clearfilmajesty^Tposterior, Kuraray America, Inc. NY, USA). Post-obturation radiograph was taken which showed well-obturated root canals [Figure 1f]. The patient was asymptomatic during follow-up after 6 months [Figure 1g] and was advised to get this tooth crowned.

The calcified mass thus removed was preserved in 10% neutral buffered formalin and was embedded in paraffin wax for the histopathological evaluation [Figure 1h]. The histopathological result revealed multiple calcified masses lying free within the pulp tissue. These calcified masses varied in their size and were scattered throughout the substance of pulp, they resembled dystrophic calcification [Figure 1i].

DISCUSSION

As per Bernick and Nedelman,[1] it appears that pulp stone prevalence can be close to 100%, particularly if associated with carious or restored first molars. Prevalence of pulp stones in maxillary first molars that were restored and/or carious had significantly higher occurrences (41.7%) as opposed to those were unrestored and intact (28.8%).[7] The case report presented was in an agreement with these findings as the maxillary left first molar had a deep occlusal carious lesion.

Pulp stones have been described as symptoms of changes in the pulp tissues rather than their cause.[8] Radiographs may show pulp chamber or root canal calcification, which may explain reduced responses to pulp sensitivity tests.[9] In accordance, the presented case showed no response on a very high level of current on electric pulp testing as compared to the healthy control tooth. The case presented had a history of dull and gnawing pain with moderate intensity; and hence, was advised for root canal therapy.

Langeland[10] discussed the clinical relevance of pulp stones in terms of their effect upon root canal treatment. The presence of pulp stone may alter the internal anatomy and confuse the operator by obscuring, but not totally blocking the orifice of the canal. Attached denticles may deflect or engage the tip of exploring instruments in the canals, thus preventing their easy passage down the canal. The pulp stone in the presented case was of enormous size and was blocking the entry to the palatal canal.

Clinically, pulp stones even large ones, are very common and many methods can be used to remove them from the pulp chamber and root canals. Sometimes a large pulp stone can be dissected out of an access cavity using burs, but ultrasonic instrumentation with the use of special tips makes their removal easier.[11,12] Accordingly, in the presented case report a specific ultrasonic tip, Start X™ #3 (Dentsply Maillefer) had been used which is meant for scouting of the calcified canal. It is characterized by a sharp and pointed end along with longitudinal rounded microblades separated by grooves. This blade design increases efficiency and precision in the removal of calcifications.

Within narrow canals, ultrasonics should ideally be coupled with the dissolving action of sodium hypochlorite on the collagen-based tissues in the canal to produce a synergistic effect.[13] In accordance with the case presented, it was treated using special ultrasonic tips START-X™ (Dentsply Maillefer) with a combination of 5.2% sodium hypochlorite and 17% EDTA solution as an irrigant.[14] Histopathological evaluation revealed multiple calcified masses lying free within the pulp tissue. These calcified masses varied in their size and were scattered throughout the substance of pulp, and with no dentinal tubules. They resembled dystrophic calcification and hence were diagnosed as partially calcified pulp tissues or free false pulp stones

CONCLUSION

The large sized pulp stones may block access to canal orifices and alter the internal anatomy of the pulp. Use of contemporary aids for illumination, magnification and instrumentation may lead to success in such a difficult and probably an overlooked clinical problem.