What can cause the pulps of immature, permanent teeth with open apices to become necrotic and what treatment options are available for these teeth

Evaluation of Microleakage of Orthograde Root-Filling Materials in Immature Permanent Teeth: An In Vitro Study

Introduction: The absence of a barrier in an open root apex makes endodontic treatment challenging as root-filling material can easily reach the surrounding tissue. The aim of the study was to compare the apical microleakage associated with mineral trioxide aggregate (MTA), biodentine, custom-made gutta-percha with MTA plus and custom-made gutta-percha with Adseal in immature permanent teeth by dye penetration method. Methods: Apical 2 mm of 60 single-rooted mandibular premolar teeth was resected to create divergent open apices and 10 teeth each were filled with Biodentine plug, MTA plug, custom-made gutta-percha with MTA plus sealer and custom-made gutta-percha with Adseal sealer. Ten teeth each acted as positive and negative controls. All the samples were stored at 37°C at 100% humidity for 5 weeks and then immersed in 2% Rhodamine B dye for 24 h. Transverse sectioning was done apically at 1 mm and 3 mm to evaluate dye penetration under a fluorescence microscope using ImageJ software. Results: There was a significantly greater microleakage at 1 mm cross section compared to 3 mm (p < 0.0001). At 1 mm cross section, the apical microleakage was the highest for the MTA plug with a mean leakage percentage of 48.08 ± 16.38, a mean depth of leakage of 0.46 ± 0.10 mm and a mean area of leakage of 1.35 ± 0.74 mm2, compared to other groups, and the difference was statistically significant. However, at a 3 mm cross section, MTA plus sealer with gutta-percha demonstrated the highest mean leakage percentage (25.01 ± 7.77) compared to other groups and the difference was statistically significant (p = 0.03). Conclusion: It can be concluded that the 3-mm-thick apical plug provided better sealing of the open apex compared to the 1 mm apical plug and there was no significant difference in microleakage among the Biodentine plug, MTA plug and Adseal sealer with gutta-percha plug at 3 mm cross section.

Successful retreatment of a maxillary central incisor with a wide-open apex using MTA to fill the entire canal: 24-year follow-up

Managing teeth with open apices can be a challenging scenario for clinicians. This case report describes the 24-year follow-up of a maxillary central incisor that failed to develop after a traumatic injury resulting in a wide-open apex. A 10-year-old girl presented complaining of discomfort in her upper teeth. Tooth #9 had received a traumatic blow several years before and was discoloured with a resin composite restoration on the mesio-incisal edge. The tooth was painful to percussion and palpation. An inadequate root canal filling and incomplete root formation were observed on the initial periapical radiograph. Root canal retreatment was initiated, and the canal filled entirely with mineral trioxide aggregate (MTA) because of the extremely wide canal and open apex. The patient was asymptomatic at the 24-year follow-up with the cone beam computed tomography and periapical radiographs demonstrating the stability of the MTA.

Pulp regeneration treatment using different bioactive materials in permanent teeth of pediatric subjects

Background and Objectives

The present systematic review aims to assess the success rate of the pulp regeneration treatment, according to the American Association of Endodontists (AAE) criteria, using different bioactive materials in permanent teeth of pediatric subjects (6-17 years of age).

Materials and Methods

The study protocol was registered on PROSPERO and adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. The question formulation was accomplished using the PICO model, and an electronic search was carried out on Scopus, MEDLINE/PubMed, Web of Science, and Cochrane databases till April 1, 2023. A total of 30 studies were established to fulfill the inclusion criteria of this systematic review.

Results

A total of 273 teeth have been treated with pulp regeneration treatment. By comparing different biomaterials and the success criteria defined by the AAE, the material associated with a higher success rate was found to be the white mineral trioxide aggregate. However, the overall success rate of pulp regeneration treatment was reported for 248 out of 273 teeth (91.20%).

Conclusions

Data obtained support the potential that regenerative endodontics aids in continuing root development in permanent immature teeth. Further studies are needed for a more extensive evaluation of the use of different biomaterials and the success rate in regenerative endodontics.

Open Apex and its Management: Review Article

During root development, the teeth are subjected to a variety of assaults. Due to this, the root stops forming and the closure of the apex does not take place. Root canal treatment becomes a major challenge in these cases because of the width of the canal and wide-open apices. Management of open apices includes apexogenesis in vital young permanent teeth and apexification, which is a method to induce a calcified barrier in the root. Newer concepts include regeneration and revascularization procedures, which still need to be experimented with further.

Is Etiology a Key Factor for Regenerative Endodontic Treatment Outcomes?

INTRODUCTION

This study aimed to evaluate treatment outcomes of regenerative endodontic treatment (RET) in nonvital immature permanent teeth due to developmental malformation and trauma, and to analyze the influence of etiology on the prognosis.

METHODS

Fifty-five cases were included and divided into a malformation group (n=33) and a trauma group (n=22). Treatment outcomes were classified as healed, healing and failure. Root development was evaluated in terms of root morphology and the percentage changes in root length, root width and apical diameter during a follow-up period of 12 to 85 months (mean 30.8 months).

RESULTS

The mean age and the mean degree of root development in the trauma group were significantly younger than that in the malformation group. The success rate of RET was 93.9% (81.8% healed, 12.1% healing) in the malformation group and 90.9% (68.2% healed, 22.7% healing) in the trauma group, showing no statistically significant difference. The proportion of type I-III root morphology in the malformation group (97%, 32/33) was significantly higher than that in the trauma group (77.3%, 17/22) (P<0.05), whereas there was no significant difference in the percentage changes of root length, root width and apical diameter between the two groups. Six cases (6/55, 10.9%) showed no significant root development (type IV-V) (1 in the malformation group and 5 in the trauma group). Six cases (6/55, 10.9%) revealed intracanal calcification.

CONCLUSIONS

RET achieved reliable outcomes regarding the healing of apical periodontitis and continued root development. The etiology seems to influence the outcome of RET. Malformation cases presented with a better prognosis than trauma cases after RET.

Is Revascularization the Treatment of Choice for Traumatized Necrotic Immature Teeth? A Systematic Review and Meta-Analysis

Regenerative endodontic treatment (RET) has been considered a reliable procedure to treat immature necrotic teeth; however, the effect of dental trauma on the prognosis of RET is questionable. This systematic review aimed to evaluate the current level of evidence for revascularization techniques (the RET) in the management of traumatized necrotic immature permanent teeth with or without periapical radiolucent areas. Four electronic databases-PubMed, Web of Science, Scopus, and Embase-were searched until November 2022. Only randomized clinical trials, cohort studies, and case-control studies with a minimum of 10 cases and 12 months of follow-ups were included. The search identified 363 preliminary results. After discarding the duplicates and screening the titles, abstracts, and full texts, 13 articles were considered eligible. The results showed that RET techniques seemed to have high survival and success rates, 93.8% and 88.3%, respectively, in the treatment of traumatized necrotic immature permanent teeth. Root maturation with RET techniques seemed to be lower in traumatized teeth. Future studies are needed to evaluate root maturation in traumatized teeth using 3-dimensional radiographic evaluations. In addition, the lack of literature on the studies comparing RET and apexification (calcium hydroxide or an MTA) in the treatment of traumatized necrotic immature teeth highlights the necessity for high-level clinical studies comparing these treatment modalities.

Treatment Outcomes of Permanent Immature Teeth with Crown Fracture: A Retrospective Cohort Study

INTRODUCTION

Crown fractures are a common type of traumatic dental injury. Various factors may affect the outcome of crown fractures. This study aimed to evaluate the treatment outcomes of immature teeth with a crown fracture.

METHODS

This retrospective cohort study included patients who presented to a dental trauma center from 2008-2018 with a history of a crown fracture of immature teeth and at least 6 months of follow-up. Outcomes of primary endodontic or restorative interventions as well as reinterventions were evaluated. Kaplan-Meier curves were used to compare the unadjusted differences in survival time. Logistic and Cox regression analyses were performed to identify potential predictors for complication and survival time, respectively.

RESULTS

The success rates of the primary interventions for 99 teeth (72 patients) after a median follow-up of 22 months were as follows: cervical pulpotomy (90.4%), partial pulpotomy (85.2%), mineral trioxide aggregate apical barrier (80.0%), root canal treatment (66.6%), and only restoration (47.2%). Teeth that received vital pulp therapy were less prone to complications (adjusted hazard ratio = 0.21; 95% confidence interval, 0.09-0.53; P < .05), whereas those with concomitant luxation injuries were more susceptible to complications (adjusted odds ratio = 2.90; 95% confidence interval, 1.01-8.29; P < .05).

CONCLUSIONS

Crown fractures had a relatively high favorable prognosis. Vital pulp therapy (partial or cervical pulpotomy) had the highest success rate, whereas cases that received only restoration had the lowest success rate. Teeth with concomitant luxation injuries had more odds and hazards of complications.

Effect of mineral trioxide aggregate and biodentine™ on fracture resistance of immature teeth dentine over time: in vitro study

PURPOSE

The aim of this in vitro study was to evaluate the effect of root filling with White Mineral Trioxide Aggregate (WMTA) and Biodentine™ (BD) on the fracture resistance of simulated immature teeth over different time periods.

METHODS

Sixty sound-extracted human single-rooted premolars were randomly allocated into 3 groups, 2 experimental and 1 control group, with 20 teeth each. Simulation of roots into immature apices were done using Peeso reamers. After preparation, the root canals of teeth in the experimental groups were completely filled with either WMTA or BD. The control group was subdivided into positive controls (n = 10) which received no treatment and negative controls (n = 10) which were prepared the same way and filled with normal saline. The specimens were subjected to fracture testing using a universal testing machine after 2 weeks and 3 months. The peak load to fracture and the fracture location were recorded.

RESULTS

Regarding fracture resistance, the MTA group had the highest fracture resistance at 2 weeks testing, while at 3 months there was no significant difference between the groups (P > 0.05). Regarding fracture location, at 2 weeks there was no significant difference in the fracture location between the groups, while at 3 months, the difference was significant (P < 0.05), the middle root fracture being the most frequent (63.3%).

CONCLUSION

No significant difference in fracture resistant of simulated immature teeth was observed after 3 months when they were filled with Biodentine or WMTA, indicating that Biodentine could be a suitable substitute for MTA. There was no difference in the possible fracture location at 2 weeks, while after 3 months middle root fractures were more frequent.

Incorporation of amoxicillin-loaded microspheres in mineral trioxide aggregate cement: an in vitro study

Objectives

In this study, we investigated the potential of amoxicillin-loaded polymeric microspheres to be delivered to tooth root infection sites via a bioactive reparative cement.

Materials and Methods

Amoxicillin-loaded microspheres were synthesized by a spray-dray method and incorporated at 2.5% and 5% into a mineral trioxide aggregate cement clinically used to induce a mineralized barrier at the root tip of young permanent teeth with incomplete root development and necrotic pulp. The formulations were modified in liquid:powder ratios and in composition by the microspheres. The optimized formulations were evaluated in vitro for physical and mechanical eligibility. The morphology of microspheres was observed under scanning electron microscopy.

Results

The optimized cement formulation containing microspheres at 5% exhibited a delayed-release response and maintained its fundamental functional properties. When mixed with amoxicillin-loaded microspheres, the setting times of both test materials significantly increased. The diametral tensile strength of cement containing microspheres at 5% was similar to control. However, phytic acid had no effect on this outcome (p > 0.05). When mixed with modified liquid:powder ratio, the setting time was significantly longer than that original liquid:powder ratio (p < 0.05).

Conclusions

Lack of optimal concentrations of antibiotics at anatomical sites of the dental tissues is a hallmark of recurrent endodontic infections. Therefore, targeting the controlled release of broad-spectrum antibiotics may improve the therapeutic outcomes of current treatments. Overall, these results indicate that the carry of amoxicillin by microspheres could provide an alternative strategy for the local delivery of antibiotics for the management of tooth infections.

Evaluation of different Apexification treatments of teeth with immature apices and apical periodontitis on the fractal dimensions of trabecular bone

The aim of the present study was to investigate in the fractal dimension (FD) time-dependent changes of periapical bone after two different apexification treatments in teeth with immature apices and apical periodontitis. This study included 55 cases treated with apexification. Cases were divided into two groups: a calcium hydroxide group and a mineral trioxide aggregate group. In each case, the lesion area was evaluated by fractal analysis on periapical radiographs obtained before and 1-year after treatment via Image-J program. The FD of each region of interest on the radiographs was calculated using the fractal analysis method. The data were statistically analysed. In both groups, the FD values increased compare to initial at 1-year follow-up after treatment (P < .05). There was no statistically significant difference between the groups in terms of the time-dependent increase in FD values (P = 0.118). In the present study, time-dependent changes in FD were independent of the apexification method.

Materials used in regenerative endodontic procedures and their impact on tooth discoloration

There is some evidence of tooth discoloration after regenerative endodontic procedures. The aim of this review is to determine which materials used in regenerative procedures induce tooth discoloration. The authors searched six digital databases in February 2018: PubMed, Google Scholar, the Cochrane Library, Scopus, Web of Science, and Lilacs. As a result, 353 studies were found. Eleven studies that met the established criteria were selected. Analysis of the selected studies showed that most materials used in regenerative endodontic procedures have the potential to stain tooth tissues. To decrease tooth discoloration, sealing dentin with a dentin-bonding agent before the placement of a disinfectant paste and barrier materials should be considered. Only a small number of in vitro studies have been performed; therefore, further studies on this topic are warranted.

A zinc-doped endodontic cement facilitates functional mineralization and stress dissipation at the dentin surface

BACKGROUND

The purpose of this study was to evaluate nanohardness and viscoelastic behavior of dentin surfaces treated with two canal sealer cements for dentin remineralization.

MATERIAL AND METHODS

Dentin surfaces were subjected to: i) 37% phosphoric acid (PA) or ii) 0.5 M ethylenediaminetetraacetic acid (EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide (oxipatite), respectively. Samples were stored in simulated body fluid during 24 h or 21 d. The intertubular and peritubular dentin were evaluated using a nanoindenter to assess nanohardness (Hi). The load/displacement responses were used for the nano-dynamic mechanical analysis to estimate complex modulus (E*) and tan delta (δ). The modulus mapping was obtained by imposing a quasistatic force setpoint to which a sinusoidal force was superimposed. AFM imaging and FESEM analysis were performed.

RESULTS

After 21 d of storage, dentin surfaces treated with EDTA+calcypatite, PA+calcypatite and EDTA+oxipatite showed viscoelastic discrepancies between peritubular and intertubular dentin, meaning a risk for cracking and breakdown of the surface. At both 24 h and 21 d, tan δ values at intertubular dentin treated with the four treatments performed similar. At 21 d time point, intertubular dentin treated with PA+oxipatite achieved the highest complex modulus and nanohardness, i.e., highest resistance to deformation and functional mineralization, among groups.

CONCLUSIONS

Intertubular and peritubular dentin treated with PA+oxipatite showed similar values of tan δ after 21 d of storage. This produced a favorable dissipation of energy with minimal energy concentration, preserving the structural integrity at the dentin surface.