Recurrent Apical Periodontitis and Late Endodontic Treatment Failure Related to Coronal Leakage: A Case Report

Comparative Analysis of Coronal Sealing Materials in Endodontics: Exploring Non-Eugenol Zinc Oxide-Based versus Glass-Ionomer Cement Systems

The proper closure of the access cavity between appointments during endodontic treatment is paramount and relies on temporary fillings. This systematic review evaluates the effectiveness of zinc oxide-based materials and glass-ionomer cement (GIC) as temporary coronal sealers after root canal treatment in extracted human teeth. Three databases were searched to identify randomized clinical trials that examined the sealing properties of various temporary sealing materials using dyes or stains as indicators. A total of seven in vitro studies that fulfilled the eligibility criteria were critically analyzed. These indicated significant variations in the relative sealing ability of the coronal breach of endodontically treated teeth, either by zinc oxide or GIC-based materials. While GIC-based material (e.g., Fuji IX and Fuji II) exhibited superior sealing of single-rooted teeth, zinc oxide-based material (e.g., Cavit, Coltosol, Caviton) also showed promising attributes. Resin-modified GIC formulations displayed enhanced physical properties, yet challenges related to adhesive failure and shrinkage during polymerization were observed. Zinc oxide-based materials have demonstrated superior coronal sealing effectiveness over certain GIC in controlled settings. Their premixed nature ensures consistent application and hygroscopic properties improve cavity sealing. However, the focus on dye penetration tests for microleakage in vitro may not fully represent the risk of bacterial infiltration. Thus, in vivo studies are crucial for validating these findings in clinical contexts.

Surgical management of a lateral lesion refractory to root canal retreatment caused by an extraradicular calculus. A case report

This article describes the management of a root canal-treated maxillary central incisor displaying a radiographic lateral radiolucency and a sinus tract that persisted irrespective of root canal retreatment following high standards. Endodontic microsurgery was indicated and curettage of the pathologic tissue revealed a calculus-like material attached to the outer root surface around the exit of a large lateral canal. A non-conventional approach was chosen: No root-end resection was conducted. Instead, the calculus was removed and the apical surface was scaled and smoothed, conserving the apical structure. Retrocavities were prepared in both lateral and apical foramens and filled with a bioceramic material. Follow-up examination showed optimal soft tissue healing. One-year follow-up of radiographs revealed healing of the lateral lesion. The lesion was diagnosed as a cyst, with an infected lumen. An exuberant calculus-like material attached to the external root surface was the most likely cause of the recalcitrant lateral periradicular lesion.

The Influence of Root Canal Preparation with ProTaper Next, WaveOne Gold, and Twisted Files on Dentine Crack Formation

(1) Background: Root canal preparation constitutes an important factor for success in endodontics. However, various complications may occur during this stage. The aim of this study was to compare the incidence of cracks within radicular dentin after instrumentation with ProTaper Next (PTN), WaveOne Gold (WOG), and Twisted Files (TF), which utilize different kinematics. (2) Methods: Eighty single-rooted teeth were classified into four groups (n = 20). Three groups were instrumented using PTN (X1, X2), WOG (Primary), and TF (SM1–3). The non-instrumented group constituted the control group. Post-preparation, the roots were sectioned 3, 6, and 9 mm from the apex using a low-speed saw (Southbay Technology Inc., San Clemente, CA, USA). The specimens were viewed through a microscope at x25 magnification (Leica M320, Wetzlar, Germany), and their surface was assessed tactilely to determine the presence of the crack. (3) Results: Partial cracks within radicular dentine were observed in all study groups (PTN: n = 4/20%, WOG: n = 3/15%, TF: n = 4/20%); no cracks were observed in the control group. No significant differences were observed among experimental groups. OR values for the incidence of cracks were: OR = 11.182 for PTN, OR = 8.2 for WOG, and OR = 8.2 for TF. (4) Conclusions: Instrumentation with PTN, WOG, and TF may result in dentinal cracks formation.

Efficacy of prototype endodontic obturators for novel root canal obturation techniques using a resin-based sealer in various powder-liquid ratios

PURPOSE

This study aimed to examine novel techniques using prototype endodontic obturators to obturate a resin-based sealer.

METHODS

Powder-liquid ratios of MetaSEAL Soft were changed to obtain suitable root canal sealing, and the physical properties for various powder-liquid ratios were analyzed according to ISO-6876. Tensile bond strength was also examined. Prototype endodontic obturators with a combination of thread numbers and pitch angles were analyzed for sealing ability after MetaSEAL Soft was obturated in simulated root canals.

RESULTS

Powder-liquid ratios of 1.0:1, 1.1:1, 1.2:1, and 1.3:1 showed suitable physical properties; however, flow for 1.4:1 was below a standard value. Tensile bond strength increased gradually when the powder-liquid ratio changed from 1.0:1 to 1.3:1, and 1.3:1 and 1.4:1 showed the highest and lowest bond strengths, respectively. Sealing ability increased when pitch angles of the obturators were 5°, 8°, and 11°; 11° showed the best results. Similarly, sealing ability increased when the thread number was 12, 17, and 22 pitches; 22 showed the best results.

CONCLUSION

These findings suggest that the prototype endodontic obturator can be useful for obturating MetaSEAL Soft, and a powder-liquid ratio of 1.3:1 MetaSEAL Soft may be the most suitable for achieving excellent sealing.

Assessment of Ramifications in the Apical Region of Root Canals: A Micro-CT Study in a Brazilian Population

The present study used microcomputed tomography (micro-CT) images to assess the prevalence, number, and location of apical ramifications (ARs) in the root canals of different dental groups in a Brazilian population. Three hundred and sixty-seven extracted human teeth, totaling 475 roots, were scanned by micro-CT at 19.6 µm spatial resolution. The obtained images were evaluated by two observers in consensus, and a descriptive analysis was performed to verify the prevalence, number, and location of ARs in each dental group. Chi-square test was used to compare the prevalence of ARs in different types of roots, and one-way analysis of variance compared the number of ARs in the apical 1 mm, 2 mm, and 3 mm of the root. Significance level was established at 5% (α=0.05). ARs were present in 253 (53.3%) of the 475 roots evaluated. A total of 607 ARs were detected, with the vast majority (530) located at one and two millimeters from the main foramen. The highest prevalence of ARs was observed in maxillary canines (65%); maxillary premolars - single-rooted (83.3%), buccal root (80%), and palatine root (73.3%); mandibular premolars (64.2%); mesiobuccal root of maxillary molars (76.6%); and mesial root of mandibular molars (66.6%). For the Brazilian population, most of the ARs are located in the apical 1 and 2 mm of the root, with greater prevalence in the posterior teeth and maxillary canines. These findings suggest the need for additional attention while planning endodontic treatments, including strategies to effectively clean and fill the apical region.

Root canal treatment of compromised teeth as alternative treatment for patients receiving bisphosphonates: 60-month results of a prospective clinical study

AIM

This 60-month prospective study aimed to evaluate tooth survival and healing rates after root canal treatment in patients taking bisphosphonates (BPs). Secondary outcomes were complications and clinical variables observed during and after treatment.

METHODS

Root canal treatment was performed using manual K-file canal instrumentation and a carrier-based filling technique with an epoxy resin-based sealer. Teeth without adequate root/crown integrity were restored by trained operators at the tissue level (TL group) to prevent occlusal/mechanical stress and to enable periapical lesion healing without the risk of root fracture. Other teeth were restored with normal occlusal contacts (OC group). Healthy patients who had undergone one or more root canal treatments of the same type constituted the control group. The relationships of the following variables to survival and health status were examined (chi-squared test and multivariate analysis, P = 0.05): age, gender, smoking habit, tooth location, treatment type, BPs treatment, BPs exposure, initial periapical index (PAI) and occlusal restoration. Survival curves were constructed using Kaplan-Meier analysis, with extraction serving as the end-point.

RESULTS

In total, 65 patients with 109 root canal-treated teeth who were taking BPs were included. At 60 months, data from 57 patients (52F, 5M; median age 65.7 ± 8.6 years) who had undergone 96 root canal treatments were analysed (drop-out rate = 16.9%). The survival rate was 85%, and the success rate was 76%. The control group consisted of 46 patients (21F, 25M; median age 60.3 ± 7.2 years) who had undergone 102 root canal treatments. The survival rate was 88%, with 12 teeth lost during follow-up. The success rate was 73%. In the BP group, 55 teeth were restored normally (OC group) and 41 teeth were restored at the tissue level (TL group). No difference in the success or survival rate was observed between the BP and control groups (P > 0.05). Univariate Kaplan-Meier analysis revealed that only tooth type significantly affected survival status in the BP group. The analysis revealed the clinical relevance of smoking, tooth location and initial PAI on patients' health status (P < 0.05).

CONCLUSION

Root canal treatments and post-endodontic restoration with tissue-level filling procedures represent a safe approach for severely damaged teeth in patients receiving BPs having comparable results to root filled teeth restored with occlusal contacts and to the control group.

LncRNA AWPPH overexpression predicts the recurrence of periodontitis

Long non-coding RNA (LncRNA) AWPPH is a recently identified oncogenic lncRNA, while its role in other human diseases is still unknown. Blood samples from 80 periodontitis (periodontitis group) patients and 66 healthy controls (control group) who were admitted and treated by Peking University School and Hospital of Stomatology, expression levels of lncRNA AWPPH were detected by RT-PCR. In the present study, we showed that, before treatment, lncRNA AWPPH in plasma was up-regulated in periodontitis patients than in healthy controls. After treatment, expression levels of lncRNA AWPPH reduced significantly. Patients were followed up for 2 years to recorded recurrence. Compared with plasma levels of lncRNA AWPPH on the day of discharge, lncRNA AWPPH expression level increased significantly in patients with recurrence but not in patients without recurrence during follow-up. Based on Youden's index, patients were divided into high and low lncRNA AWPPH groups according to its expression level on the day of discharge. It was observed that the recurrence rate of periodontitis is significantly higher in high lncRNA AWPPH group than in low lncRNA AWPPH group. LncRNA AWPPH overexpression predicts the recurrence of periodontitis.

A CAD/CAM-based strategy for concurrent endodontic and restorative treatment

This case report describes a technique in which endodontic treatment and permanent indirect restoration were completed in the same clinical appointment with the aid of a computer-aided design/computer-aided manufacturing (CAD/CAM) system. Two patients were diagnosed with irreversible pulpitis of the mandibular first molar. After access preparation, root canals were located, irrigation was performed until bleeding ceased, and the coronal tooth structure was prepared for indirect restoration. Then, utilizing an interim 3-mm build-up of the endodontic access cavity, a hemi-arch digital scan was performed with an intraoral scanner. Subsequent to digital scanning, restoration design was performed simultaneously with the endodontic procedure. The root canals were shaped using the Race system under irrigation with 2.5% sodium hypochlorite followed by root canal filling. The pulp chamber was subsequently filled with a 3-mm-thick composite resin restoration mimicking the interim build-up previously utilized to facilitate block milling in the CAD/CAM system. Clinical try-in of the permanent onlay restoration was followed by acid etching, application of a 5th generation adhesive, and cementation of the indirect restoration. Once the restoration was cemented, rubber dam isolation was removed, followed by occlusal adjustment and polishing. After 2 years of follow-up, the restorations were esthetically and functionally satisfactory, without complications.

Biofilm model systems for root canal disinfection: a literature review

The aim of this review was to present an overview of laboratory root canal biofilm model systems described in the endodontic literature and to critically appraise the various factors that constitute these models. The electronic databases MEDLINE, Web of Science and EMBASE were searched up to and including December 2016 to identify laboratory studies using endodontic biofilm models. The following search terms were used in various combinations: biofilm, root canal, in vitro, endodontic, bacteria, root canal infection model, colony-forming unit. Only English papers from journals with an impact factor were selected. The records were screened by two reviewers, and full-text articles were assessed according to pre-defined criteria. The following data were extracted from the included studies: the microbial composition of the biofilm, the substrate, growth conditions, validation and quantification. Seventy-seven articles met the inclusion criteria. In the majority (86%) of the studies, a monospecies biofilm was cultured. In two studies, a dual-species biofilm was grown; others cultivated a multispecies biofilm, containing at least three species. Enterococcus faecalis was the most frequently used test species (in 79% of all studies, 92% of the monospecies studies). Four studies used an inoculum derived directly from the oral cavity. Human dentine was the most frequently used substratum (88% of the studies). Incubation times differed considerably, ranging from one to seventy days. The most common quantification method (in 87% of the studies) was bacterial culturing, followed by microscopy techniques. The variation in laboratory root canal biofilm model systems is notable. Because of substantial variation in experimental parameters, it is difficult to compare results between studies. This demonstrates the need for a more standardized approach and a validated endodontic biofilm model.

Long-term treatment outcomes in immature permanent teeth by revascularisation using MTA and GIC as canal-sealing materials: a retrospective study

BACKGROUND

Pulp revascularisation with MTA sealing has been accepted as an alternative treatment for non-vital immature permanent teeth. Successful revascularisation cases with GIC sealing were also reported, but lack of long-term researches.

AIM

To evaluate long-term outcomes of revascularisation using MTA and GIC as canal-sealing materials in non-vital immature permanent teeth.

DESIGN

Clinical and radiographic data of 60 non-vital immature permanent teeth treated with revascularisation (36.8 ± 12.4 months of follow-up) were reviewed. Of these, 28 teeth were sealed with MTA, and 32 with GIC. Tooth survival, success rate, and increases in root length and dentine wall thickness were evaluated.

RESULTS

Teeth in MTA group showed a similar survival rate (96%) to GIC group (100%). The success rate in MTA group (93%) was greater than that in GIC group (59%). Eight of fourteen failed teeth due to recurrent apical disease (seven teeth in GIC group and one in MTA group) achieved complete root development. There was no statistically significant difference in root length or dentine wall thickness increase between the groups.

CONCLUSIONS

Long-term outcome of revascularisation in non-vital immature permanent teeth sealed with GIC was not as good as that with MTA. Although more recurrent apical disease developed, results on root development were acceptable in GIC sealed cases.

Assessment of Coronal Leakage of Temporary Restorations in Root Canal-treated Teeth: An in vitro Study

INTRODUCTION

Coronal leakage is one of the constant concerns in routine dental practice. It is one of the factors responsible for the failure of root canal therapy. Permanent restorations should be given as soon as possible after the completion of root canal therapy. If unavoidable, provisional restoration should be given in such a way that it maximally reduced the leakage of microorganisms and fluids from the external environment into the canal space. Hence, we evaluated the effect of saliva on the coronal leakage of temporary restorations.

MATERIALS AND METHODS

Biomechanical preparation of the root canals of 204 fresh mandibular first premolar teeth was done using endodontic files with intermittent irrigation of sodium hypochlorite solution and ethylenediaminetetraacetic acid. Alternate irrigation with normal saline was done periodically. After preparation, drying of the canals was done using paper points followed by sealing of the apical foramen. For the assessment of the microleakage, Siqueira et al apparatus and method was used. All the specimens were divided into four groups based on the provisional restorative material used. All the groups were further divided into three subgroups based on the presence and absence of intracanal medicaments. Verissimo et al's criteria were used to check the turbidity at 1-, 2-, 3-, and 4-week interval respectively. All the results were analyzed by Statistical Package for the Social Sciences (SPSS) software. Chi-square test was used to measure the level of significance, and p < 0.05 was considered to be significant.

RESULTS

In group I, all the subgroups' specimens showed significant difference at 1 week's time. Only the subgroup with no intracanal medicaments in Cavit-containing provisional restoration showed nonsignificant alterations. Statistically significant alterations were seen at 1, 2, and 3 weeks' interval in all the subgroups except for one with intracanal medicaments.

CONCLUSION

All the temporary restorative materials were not able to prevent microleakage after 1 week's time, with worst bacterial resistance shown by Ketac Molar and ionomer restorative material. Future studies are advocated for better prognosis of root canal therapy.

CBCT-based Diagnosis of Periapical Lesion of Maxillary First Premolar Mimicking That of Second Premolar

Apical periodontitis is usually diagnosed based on clinical findings and dental X-rays. Recently, however, dental cone beam computed tomography (CBCT), which provides 3-D images of the maxillofacial region, has enabled dentists to examine patients undergoing endodontic therapy more effectively, improving diagnostic accuracy. Here, we describe a positive treatment outcome achieved using CBCT to diagnose apical periodontitis of the maxillary premolars, which had proven difficult to diagnose based on clinical findings and dental radiography alone. The patient was a 42-year-old Japanese man who presented with the chief complaint of gingival swelling in the maxillary right premolar region. Our initial diagnosis, based on clinical findings and dental X-ray, was apical periodontitis of the maxillary right second premolar, and treatment was started. However, after the patient failed to respond to the treatment, CBCT was performed. Based on these new findings, the diagnosis was changed to one of apical periodontitis of the upper right first premolar, and the patient was treated accordingly. Previous studies have described the complex anatomical morphology of the upper premolars, noting multiple roots and variation in the morphology of the root canals. The 3-D images provided by dental CBCT allow better assessment of oral conditions than the traditional 2-D images provided by dental X-rays, which in turn enables the dentist to better select the most appropriate treatment. Here, the patient showed no symptoms and was progressing well at a 6-month follow-up visit. The present results indicate that when clinical findings and dental X-rays alone are insufficient to allow a secure diagnosis, CBCT offers an effective alternative which will enable the appropriate treatment to be selected more reliably.

Effect of different gutta-percha solvents on the microtensile bond strength of various adhesive systems to pulp chamber dentin

OBJECTIVES

The aim of this study was to evaluate the effect of different endodontic solvents on the microtensile bond strength (μTBS) of various adhesives to pulp chamber dentin.

MATERIAL AND METHODS

A total of 120 human third molars were selected. Canals were prepared with the ProTaper Universal system and obturated. The access cavities were then restored with resin composite. After 1 week, a retreatment procedure was applied as follows: control, no solvent was applied to the pulp chamber and experimental groups, three different solvents (chloroform, eucalyptol, and orange oil) were applied to the pulp chamber for 2 min. The canal filling was removed and calcium hydroxide (Ca[OH]₂) was placed into the canals. After 7 days, the Ca(OH)₂ was removed from the canals and the canals were re-obturated. Teeth were then divided into three subgroups according to the adhesive used. The samples were restored with a nanohybrid resin composite using three different adhesives: Clearfil SE Bond (CSE), Adper Easy One (AEO), and Single Bond 2 (SB2). The samples were aged with thermocycling. Teeth were sectioned, and a total of 20 dentin sticks were obtained for each subgroup. μTBS testing was then performed. The debonded surfaces were evaluated using scanning electron microscopy (SEM) analysis. Data were analyzed using two-way ANOVA and Tukey's post hoc tests.

RESULTS

Chloroform showed statistically lower mean μTBS values (14 ± 7.2 MPa) than control group did (19.2 ± 6.1 MPa) (p < 0.05). Orange oil (18.1 ± 6.3 MPa) and eucalyptol (16.9 ± 6.8 MPa) did not reduce the mean μTBS statistically (p > 0.05). Chloroform showed significantly lower bond strength for all adhesives (p < 0.05). Whereas orange oil did not reduce the mean μTBS values of all adhesive systems significantly (p > 0.05), eucalyptol reduced the μTBS values of all the groups, but the results were only statistically significant for SB2 (p < 0.05). CSE showed statistically higher bond strength (20.4 ± 6.8 MPa) than AEO (14.6 ± 5.3 MPa) and SB2 (16.3 ± 7.2 MPa) did (p < 0.05). There were no statistical differences between AEO and SB2 (p > 0.05). According to the SEM analysis of the debonded surfaces, adhesive failures were the most common type in all the groups, followed by mixed failures.

CONCLUSIONS

While chloroform reduced the mean bond strength of the adhesive resins, orange oil did not affect the bond strength of the adhesives. The effect of eucalyptol on bond strength depended on the type of adhesive system.

CLINICAL RELEVANCE

This study shows that endodontic solvents could affect the microtensile bond strength of adhesives to pulp chamber dentin.

The Impact of Apical Patency in the Success of Endodontic Treatment of Necrotic Teeth with Apical Periodontitis: A Brief Review

Accumulation of soft tissue or dentinal remnants in the apical region is a common event that can cause blockage of root canals. This event can be avoided if apical patency is performed during the root canal shaping procedures. However, there is no consensus on the role of apical patency in relation to the success of endodontic treatment of necrotic teeth with apical periodontitis. Therefore, the purpose of this paper was to conduct a brief review on the role of apical patency in guaranteeing the success of endodontic treatments of necrotic teeth with apical periodontitis considering two other key points; the root canal anatomy and microbiology.

Polytetrafluoroetylene tape as temporary restorative material: a fluid filtration study

Purpose:

The purpose of this study was to compare the sealing ability of temporary restorative materials at 24 hrs and 1 week.

Materials and Methods:

Endodontic access cavities were prepared in 56 extracted lower incisor-teeth and divided into 5 groups (n=10). Standard 5 mm deep access preparations were completed and root canals were prepared to size ISO #30 file. The access cavities were restored as follows: Group 1: temporary restorative material (Ceivitron); Group 2: glass ionomer cement (Fuji II); Group 3: zinc oxide-eugenol cement (IRM); Group 4: zinc phosphate cement (Adhesor); Group 5: polytetrafluoroetylene tape (PTFE). The quality of the coronal sealing of each specimen was measured (24 hrs and 1 week) using fluid transport model. The data was analyzed with repeated measurements ANOVA, Tukey' HSD and Paired samples T-Tests.

Results:

A significant difference was found among the groups at all time-periods (p<0.05). At 24 hrs, PTFE showed similar leakage with Ceivitron, IRM, and Fuji II but it showed higher leakage than Adhesor. At 1 week, Ceivitron showed higher leakage than PTFE, meanwhile PTFE showed similar leakage with IRM, Fuji II, and Adhesor (p>0.05). Sealing ability of IRM and PTFE groups significantly increased by time (p<0.05 and p<0.001 respectively).

Conclusion:

Within the limitations of this study, PTFE showed an acceptable short-term sealing capability when compared to the other commonly used temporary restorative materials at 1 week measurements.

Microbial invasion of dentinal tubules: a literature review and a new perspective

Various features of endodontic microbiology have been investigated using various methods. The aim of the present study was to review the existing literature on endodontic microbiology in dentinal tubules, and to present the features of two cases with endodontic pathology. An electronic search was performed with a search string created ad hoc. Ex vivo and in vitro studies were included, recording the method of detection and characteristics of analyzed teeth. Twenty studies fulfilled the inclusion criteria. Seven of them were in vitro laboratory studies on teeth inoculated after extraction, while 13 were ex vivo studies on extracted, infected teeth. Endodontic bacteria were detected in dentinal tubules, both as single units and as biofilm aggregates. Two similar in vitro cases presented here corroborate the latter findings. A number of techniques have been utilized to observe bacteria in the dentinal tubule ecosystem. Dentinal tubules are favorable niches for microbial survival, either in the form of monomicrobial or polymicrobial communities.

Treatment planning the endodontic-implant interface

One of the most challenging treatment planning decisions in restorative dentistry is the retention of a root filled tooth or its extraction and replacement with an implant. Making an informed judgement relies upon not only clinical experience and expertise but also interpretation of the published clinical evidence. In the last few years, more robust data and closer scrutiny of the evidence has helped to understand the advantages and disadvantages of each of these treatment modalities. The purpose of this paper is to provide a narrative review of some of the factors that may influence treatment planning for root canal treated teeth and indications for whether these teeth would be better replaced by an implant. From the evidence presented it is clear that both treatments have a place in contemporary restorative dental treatment and that survival for both root filled teeth and implants are similar. Unsurprisingly, both these treatment choices require high standards of clinical expertise and careful planning to ensure the best outcome.

Exuberant Biofilm infection in a lateral canal as the cause of short-term endodontic treatment failure: report of a case

INTRODUCTION

This article describes a case in which signs and symptoms persisted in spite of the endodontic treatment following high standards to characterize a short-term failure.

METHODS

After several appointments of root canal treatment in an attempt to resolve persistent symptoms, including 106 days of calcium hydroxide intracanal medication, periradicular surgery was performed, and the root apex and the lesion were subjected to histologic and histobacteriologic analyses.

RESULTS

The lesion was diagnosed as a cyst, and the main root canal was free of bacteria and debris.

CONCLUSIONS

The cause of the short-term failure was an exuberant bacterial biofilm colonizing a lateral canal in the apical root segment. This case report highlights one of the major problems of modern endodontic therapy; bacteria located in areas distant from the main root canal can remain unaffected by treatment procedures and maintain disease. The challenge for researchers and clinicians that arises from this problem is to develop strategies, instruments, or substances that can reach those areas and achieve sufficient reduction in the infectious bioburden to permit predictable periradicular healing.