Tube-like mineralization in the dental pulp of traumatized primary incisors

Detecting calcified pulp stones in patients with periodontal diseases using digital panoramic and periapical radiographies

Background/purpose

Pulp stones are discrete calcified masses appearing in the dental pulp of healthy, disease and unerupted teeth. They are presented freely within the pulp tissue or attached and embedded in any part of coronal and radicular dentin. Here, the purposes of this study were to identify the presence of pulp stones in periodontal patients using digital panoramic and periapical radiographies, and to determine the association with gender, age, tooth type and dental arch.

Materials and methods

This is a retrospective study on selected records of 465 dental samples obtained between January and December, 2020. Data were collected from patients diagnosed with generalized chronic periodontitis and accepted the full periodontal treatment covered by the Government's Periodontal Health Care Program. Their digital panoramic (DPR) examination and full mouth periapical radiographic (DPA) examination (including 12 periapical and 4 bitewing images) were performed at the Outpatient Clinics of the Department of Stomatology, Taichung Veterans General Hospital. Patients were segregated into various groups according to their age, gender and tooth locations. All radiographic images were examined by a dental radiologist and two dentists to identify the presence of pulp stone calcifications and their associated factors using the Sirona applications software. Records were analyzed using SPSS version 22.0 based on tests of Pearson Chi-square and McNemar correlation.

Results

From 271 males and 194 females, a total of 465 DPR and 7440 DPA radiographs were studied. Pulp stone calcifications were identified in 270 (58.0%) subjects in DPR images and 348 (74.8%) subjects in DPA images (for 1 or more teeth per subject). We detected calcified opacities in 1031 teeth with DPR images and in 1326 teeth with DPA images from a total of 12,407 teeth. The incidence of pulp stones was similar across genders, but different in tooth locations and dental arch sextant. Moreover, pulp stones were detected more often on maxillary molars and subjects of old ages (>40 years). Digital panoramic and periapical radiography showed significant differences in the detection of pulp stone calcifications (P < 0.05), and detected better with digital periapical radiography examination.

Conclusion

We found 58.0% (n = 645) of our patients with pulp stones using digital panoramic radiography, and 74.8% using digital periapical radiography. Regarding individual teeth, only 8.5% of pulp stones were observed in digital panoramic radiography and 10.6% in digital periapical radiography. Pulp stones were more often seen in maxillary molar teeth and old patients of ages >40 years old using periapical radiography examination especially in those patients with periodontally condition. As a two-dimensional imaging system, digital periapical radiography is recommended for a definitive and routine assessment in patients suspected of hard tissue abnormality and pulp calcification formation.

Pulp canal obliteration: an endodontic diagnosis and treatment challenge

AIM

To review the literature on pulp chamber and root canal obliteration in anterior teeth and to establish a clear protocol for managing teeth with fine, tortuous canal systems.

SUMMARY

Pulp canal obliteration (PCO) occurs commonly following traumatic injuries to teeth. Approximately 4-24% of traumatized teeth develop varying degrees of pulpal obliteration that is characterized by the apparent loss of the pulp space radiographically and a yellow discoloration of the clinical crown. These teeth provide an endodontic treatment challenge; the critical management decision being whether to treat these teeth endodontically immediately upon detection of the pulpal obliteration or to wait until symptoms or signs of pulp and or periapical disease occur. The inevitable lack of responses to normal sensibility tests and the crown discoloration add uncertainty to the management; however, only approximately 7-27% of teeth with PCO will develop pulp necrosis with radiographic signs of periapical disease. Root canal treatment of teeth with pulpal obliteration is often challenging. This article discusses the various management approaches and highlights treatment strategies for overcoming potential complications.

KEY LEARNING POINTS

Up to 25% of traumatized anterior teeth can develop pulp canal obliteration; Discolouration is a common clinical finding in teeth with pulp canal obliteration; Up to 75% of teeth with pulp canal obliterations are symptom-free and require no treatment other than radiographic monitoring; Routine pulp sensibility tests are unreliable in the presence of pulp canal obliteration; Teeth with pulp canal obliteration in need of root canal treatment pose particular diagnostic and treatment challenges.

Apexification: the beginning of its end

Apexification is a procedure for treating and preserving immature permanent teeth that have lost pulp vitality. It contrasts apexogenesis in terms of its outcome in that apical maturation and normal root thickness cannot be obtained. Apexification has been a routine practice for such teeth for many decades, and despite a literature replete with discussion, including recent artificial barrier methods with mineral trioxide aggregate, ultimately there has been no major breakthrough to improve this treatment. Recently, two new clinical concepts have emerged. One involves a revitalization approach to achieve tissue generation and regeneration. In this method, new living tissue is expected to form in the cleaned canal space, allowing continued root development in terms of both length and thickness. The other is the active pursuit of pulp/dentine regeneration via tissue engineering technology to implant or re-grow pulps. Although the technology is still at its infancy, it has the potential to benefit immature pulpless teeth by allowing continued growth and maturation. With this understanding, it may be predicted that apexification will become less needed in years to come. This study will overview the recent concept of pulp revitalization in the treatment of immature teeth with nonvital pulps and the emerging research on pulp tissue engineering and regeneration.

A clinical and histological study of dental defects in a 10-year-old girl with pseudoxanthoma elasticum and amelogenesis imperfecta

BACKGROUND

The prominent dental feature of a 10-year-old girl was severely hypoplastic enamel in permanent teeth.

CASE REPORT

Severe dental defects were detected in a 10-year-old female patient affected by pseudoxanthoma elasticum and amelogenesis imperfecta. An orthopantomographic examination revealed a reduction of enamel thickness on the crown of all erupted and unerupted teeth, agenesis of the maxillary right second premolar, delayed eruption of mandibular first premolars, and the presence of large calcifications in all tooth pulp chambers. A detailed histological analysis of permanent mandibular first molars showed that pulp calcifications presented a concentric laminate organization and merged to almost completely obliterate the pulp chamber. Osteodentine was visible all along the pulpal surface of the radicular dentine. Broad resorption areas were present in the outermost dentine at both coronal and radicular levels. Radicular resorption areas presented a typical rectangular form and were filled with acellular cementum. Cementum thickness was highly increased on the root surface. Apposition of cellular cementum-like tissue was also observed on the coronal dentine surface.

CONCLUSION

Before treating patients affected by amelogenesis imperfecta and/or pseudoxanthoma elasticum, paediatric dentists should be aware of the presence of pulp calcifications that add to the complexity of endodontic procedures.

Development of clinical and radiographic signs associated with dark discolored primary incisors following traumatic injuries: a prospective controlled study

The purpose was to evaluate late complications of asymptomatic traumatized primary incisors with dark coronal discoloration. The clinical and radiographic signs of 97 teeth of the study group were recorded along a follow-up period that ranged between 12 and 75 months (mean >36 months). Children's age at time of injury ranged between 18 and 72 months (mean 40). The control group consisted of 102 non-discolored maxillary primary central incisors in 51 children older than 54 months with no history of dental trauma. In 50 teeth (52%) the color faded or became yellowish and in 47 (48%) it remained dark. Clinical signs of infection, that were diagnosed 5-58 months after the injury, were associated significantly more with dark than yellowish hues (83 and 17%, respectively). Teeth that had changed their color to become yellow presented more PCO than teeth with black/gray/brown coronal discoloration (78 and 6%, respectively). Arrest of dentine apposition was found in 15 teeth, one had yellow coronal discoloration and the remaining 14 had a dark shade. Eleven teeth showed inflammatory root resorption all with dark discoloration. Two atypical types of root resorption were observed: a surface resorption restricted to the lateral aspects of the apical half of the root while the root length remained unchanged and in the other expansion of the follicle of the permanent successor was observed. Expansion of the dental follicle was observed in 72% of all teeth with no significant difference between the various types of coronal discoloration but only half of the cases were associated with resorption of the root of the primary incisor. The various pathologic findings observed in the study group were either absent or rarely seen in the control group. It can be concluded that more than 50% of the primary incisors that retain their dark coronal discoloration acquired after dental injuries remain clinically asymptomatic till the eruption of the permanent successor even if they present accelerated root resorption. Asymptomatic traumatized primary incisors that retain their dark coronal discoloration may develop a sinus tract and inflammatory root resorption years after the injury. There is still a dilemma: which treatment is better for dark discolored primary incisors: early endodontic treatment or follow-up with the risk of development of infection and root resorption that may require extraction?

MC3T3-E1-conditioned medium-induced mineralization by clonal rat dental pulp cells

Dental pulp is thought to participate in supplementary mineralization, such as reparative dentin and pulp stones, but no direct proof of this has been reported. To study this process at a molecular level, we investigated the matrix mineralization of dental pulp using a clonal cell line (RPC-C2A) derived from rat incisor dental pulp. Mineralized nodules in extracellular matrix were formed by RPC-C2A cells cultured in the presence of conditioned medium (CM) from confluent osteoblastic MC3T3-E1 cells. These nodules were stained by the von Kossa method and with alizarin red S and quantified by the measurement of acid-soluble calcium deposition. This CM was most effective when collected 3-6 days after confluency and added at 50% to the culture medium. The CM-treated RPC-C2A cells showed high alkaline phosphatase activity, a high mRNA level of osteocalcin and decreases in the mRNA levels of osteopontin and osteonectin, but undetectable levels of mRNA of dentin sialophosphoprotein by Northern blot analyses. A pan-specific anti-transforming growth factor (TGF)-beta antibody and a soluble form of receptor for bone morphogenetic protein (BMP)-2/-4 did not neutralize the CM-induced mineralization. These results suggest that some soluble factor(s) other than TGF-beta or BMP-2/-4 in the CM from MC3T3-E1 cells cause differentiation of RPC-C2A cells to osteoblast-like cells.