Outcome of Orthograde Retreatment after Failed Apicoectomy: Use of a Mineral Trioxide Aggregate Apical Plug

Efficacy of the GentleWave System in the removal of biofilm from the mesial roots of mandibular molars before and after minimal instrumentation: An ex vivo study

AIM

To compare the efficacy of Enterococcus faecalis biofilm removal using the GentleWave System (GWS) (Sonendo Inc, CA) on non-instrumented versus minimally instrumented root canal systems.

METHODOLOGY

Thirty-four mandibular molars were autoclaved and allocated to four groups: Negative control (n = 5); positive control (n = 5); Group 1: non-instrumentation + GWS (NI + GWS) (n = 12); and Group 2: minimal instrumentation + GWS (MI + GWS) (n = 12). Of 34 samples, 24 samples with Vertucci type 2 configuration within the mesial root of each sample were allocated to Groups 1 and 2 and then matched based on the working length and root canal configuration. After inoculation of samples with E. faecalis for 3 weeks, the GWS was used on Group 1 without any instrumentation and Group 2 after instrumentation of mesial canals until size 20/06v. CFU and SEM analysis were used.

RESULTS

Log10 (CFU/mL) from the positive control, and Group 1 and 2 were 7.41 ± 0.53, 3.41 ± 1.54, and 3.21 ± 1.54, respectively. Both groups showed a statistically significant difference in the reduction of viable E. faecalis cells compared to the positive control (Group 1 [p = .0001] and Group 2 [p < .0001]), whilst showing no significant difference between the two tested groups (p < .05).

CONCLUSION

The use of GWS on the non-instrumented root canal system could be an effective disinfection protocol in removing the biofilm without dentin debris formation.

Low concentration zinc oxide nanoparticles enrichment enhances bacterial and pro-inflammatory resistance of calcium silicate-based cements

Calcium silicate-based cement (CSC) is a commonly used material in endodontic treatment. However, it has limited antibacterial activity, especially for cases involving primary infections. Zinc oxide nanoparticles (ZnO-NPs) are recognized for their potential in biomedical applications due to their antibacterial properties and ability to reduce inflammation. This study aims to optimize CSC by incorporating ZnO-NPs to maintain its physical properties, enhance its antibacterial activity, and reduce the production of pro-inflammatory cytokines. ZnO-NPs were integrated into a commercial CSC (Endocem MTA) at 1 wt% (CSZ1) or 3 wt% (CSZ3). Setting time, compressive strength, and X-ray diffraction were then measured. In addition, pH, calcium ion release, and zinc ion release were measured for 7 days. Antibacterial activity against Enterococcus faecalis and viability of murine macrophages (RAW264.7) were determined using colorimetric assays. Gene expression levels of pro-inflammatory cytokines in lipopolysaccharide induced RAW264.7 were evaluated using quantitative polymerase chain reaction. Results were compared to an unmodified CSC group. In the CSZ3 group, there was a significant increase of approximately 12% in setting time and a reduction of about 36.4% in compressive strength compared to the control and CSZ1 groups. The presence of ZnO-NPs was detected in both CSZ1 and CSZ3. Both CSC and CSZ1 groups maintained an alkaline pH and released calcium ions, while zinc ions were significantly released in the CSZ1 group. Additionally, CSZ1 showed a 1.8-fold reduction of bacterial activity and exhibited around 85% reduction in colony-forming units compared to the CSC group. Furthermore, the CSZ1 group showed a more than 39% reduction in pro-inflammatory cytokine levels compared to the CSC group. Thus, enriching CSC with 1 wt% ZnO-NPs can enhance its antibacterial activity and reduce pro-inflammatory cytokines without showing any tangible adverse effects on its physical properties.

A novel simplified approach for endodontic retrograde surgery in short single-rooted teeth

BACKGROUND

High technical thresholds, long operative times, and the need for expensive and specialized equipment impede the widespread adoption of endodontic microsurgery in many developing countries. This study aimed to compare the effects of a simplified, cost-effective, and time-efficient surgical approach involving orthograde obturation using biological ceramic material greater than 6 mm combined with apicoectomy for single-rooted teeth with short lengths with those of the conventional and current standard methods.

MATERIALS AND METHODS

Forty-five premolars equally categorized into three groups: conventional surgery group, standard surgery group, and modified surgery group. A µCT scan was used to calculate the volume of voids. A micro-leakage test and scanning electron microscope (SEM) were performed to assess the sealing effect. Additionally, four cases of chronic periapical periodontitis in the anterior region were selected, and the patients received either the modified approach or the standard surgery for endodontic microsurgery.

RESULTS

The volumes of voids in the apical 0-3 mm of the modified group and the standard group were comparable. The micro-leakage test and SEM examination demonstrated closely bonded fillings in the dentinal walls in both the modified surgery group and standard surgery group. The outcomes of the preliminary application of this modified procedure on patients were successful at the time of the follow-up cutoff.

CONCLUSIONS

The modified surgery group exhibited similar root canal filling and apical sealing abilities with the standard procedure for single-rooted teeth with short lengths (< 20 mm). The preliminary application of this modified surgical procedure achieved favorable results.

Assessment of bone quality of apical periodontitis treated with MTA plug and regenerative endodontic techniques

Fractal analysis (FA) is a quantitative, objective and non-invasive method that facilitates the characterisation of the tissue architecture. This study aims to compare the periapical healing at 1-year follow-up by evaluating newly generated trabecular bone with FA after Mineral trioxide aggregate (MTA) plug and regenerative endodontic treatment (RET). A total of 55 asymptomatic teeth with a single-canal, open apex and periapical lesion, treated with MTA plug or RET, were evaluated retrospectively. After considering the inclusion/exclusion criteria, FA was conducted on 30 periapical images using the box-counting method. In both groups, a significant decrease was observed in the periapical lesion size at 1-year follow-up (p < 0.01). However, there was no significant difference between the MTA plug and RET (p > 0.01). Significantly higher fractal dimension values were detected at 1-year follow-up in both MTA plug and RET cases (p < 0.01). However, the difference was not significant between the groups (p > 0.01). Both procedures seem to improve periapical healing with a new resistant bone of similar density and complexity.

Kök Uçları Farklı Açılarda Rezeke Edilmiş Dişlerin Cerrahi Olmayan Yeniden Tedavilerinde 3 Elektronik Apeks Bulucunun Doğruluğu: In-Vitro Çalışma

Aim: The accuracy of three electronic apex locators (EALs) during retreatment of root-end resected teeth with different resection bevel angles were evaluated in the present study. Materials and Methods: Forty mandibular premolar teeth were divided into two groups regarding resection bevel angle after root canal filling. In the first group, the apical 3 mm of each specimen was resected at a 0-degree bevel angle using a diamond bur. The resection bevel angle was approximately 45-degree in the second group. Electronic length measurements were obtained with a size 15 K-file advanced apically in dissolved gutta percha using Dentaport ZX, Propex Pixi, and Apit 15. The filling materials were then completely removed from the root canals, and the actual lengths up to the resection region were determined. The actual length was subtracted from the electronic length measurements for each specimen. Measurements were analyzed statistically using independent sample t-test, repeated-measures analysis of variance, and Bonferroni tests. The level of statistical significance was defined as P

Possible Causes for Failure of Endodontic Surgery - A Retrospective Series of 20 Resurgery Cases

OBJECTIVE

This study aimed to evaluate unsuccessful endodontic surgery cases for possible causes for treatment failure and evaluate if a nonsurgical retreatment (NSRTX) approach could have been a better alternative to resurgery.

METHODS

Analyses of clinical and cone-beam computed tomography (CBCT) images, periapical radiographs, and chart documentation determined study parameters. Preoperative factors were age, sex, tooth type, signs and/or symptoms, presence of periapical radiolucency, previous root canal treatment, timeline since previous endodontic surgery, presence of posts, cores, and restorations. The intra-operative factors were microsurgical classification, previous techniques, and current techniques utilized. Postoperative factors were signs and/or symptoms, time to follow-up, and healing status. The accessibility of the root canal system and the quality of the existing root filling were used to evaluate NSRTX as an alternative to resurgery.

RESULTS

A total of 1073 surgical cases from 2011-2019 were reviewed. In 14 patients, 20 cases matched the inclusion criteria and allowed for data extraction. The mean time since the previous surgery was 2.9+-2.1 years, with a mean follow-up of 9.1+-5.8 months after the resurgery. Possible reasons for failure identified were: insufficient root-end filling (leaking, off-axis preparation, lack of depth, overfill) n=12/20, 60.0%; missed anatomy (main and lateral canals, isthmus) n=9/20, 45.0%; incomplete resection n=6/20, 30.0%. In 18/20 cases (90.0%), resurgery appeared to be indicated for 2/20 cases (10.0%). Therefore, NSRTX may have been a potential alternative.

CONCLUSION

Further evidence for possible causes of failure of endodontic surgery was provided, which were primarily iatrogenic. The evaluation of CBCT and high magnification intra-operative images proved beneficial for identifying critical issues for all investigated cases.

A prospective cohort study evaluating the outcome of root canal retreatment in symptomatic mandibular first molars with periapical lesions

AIM

To evaluate the impact of various predictors on the outcome of root canal retreatment in symptomatic mandibular first molars with periapical lesions after a minimum of 2 years.

METHODOLOGY

One hundred and twenty previously root canal treated symptomatic mandibular first molars with periapical lesions which were diagnosed as symptomatic apical periodontitis or acute apical abscess with localized intraoral swelling were included. Root canal retreatment was performed by an experienced endodontist using a standardized treatment protocol. The teeth were followed up clinically and radiographically and the radiographic outcome was assessed using a modified periapical index scale (PAI). The cumulative success proportion and the influence of predictors on the outcome of the root canal retreatment were analysed using Kaplan-Meier analyses and log-rank tests, and the hazard ratios for the predictors were also investigated using Univariate Cox Proportional Hazard regression analysis at a significance level of 5%.

RESULTS

Of the 120 teeth, 103 teeth were re-examined with an 85% recall rate. The cumulative success rate was 88% in which 64% were healed and 24% were healing, and failure rate was recorded as 12%. None of the preoperative predictors, including age, gender, soft tissue tenderness, intraoral swelling, size of the lesion, PAI score, apical level and density of root canal filling before root canal retreatment, nor intraoperative predictors, such as active exudate drainage, density of root canal filling after root canal retreatment and restoration type had an influence on the outcome of root canal retreatment (p > .05). The only factor that significantly reduced the success rate of root canal retreatment was the apical level of the root canal filling; when it was more than 2 mm short of the radiographic apex in teeth where apical patency was not established, the success was significantly lower (p = .023).

CONCLUSIONS

Root canal retreatment in symptomatic mandibular first molars with periapical lesions resulted in a success rate of 88%. None of the predictors had a significant influence on the outcome, except for the apical level of the root canal filling after root canal retreatment with short root fillings being associated with significantly more post-treatment endodontic disease.

Nonsurgical endodontic management of mandibular first premolar with incomplete root-end resection

The complexity of the nonsurgical endodontic retreatment should be weighed against the benefit of surgical approach. This case report describes uncommon diagnosis and successful nonsurgical endodontic management of mandibular first premolar with a previous history of failed apicoectomy and incomplete root-end resection using mineral trioxide aggregate and cone-beam computed tomography.

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.

Volume of Voids in Retrograde Filling: Comparison between Calcium Silicate Cement Alone and Combined with a Calcium Silicate-based Sealer

INTRODUCTION

The aim of this study was to compare the volume of voids between retrograde filling using calcium silicate cement alone and retrograde filling using a combination of calcium silicate cement with a calcium silicate-based sealer.

METHODS

Twenty single-rooted, extracted human teeth were instrumented with nickel-titanium files and obturated with gutta-percha. We resected the roots at a point 3 mm from the apex, prepared the root ends, and filled the root-end cavities with Endocem Zr (Maruchi, Wonju, Korea) or Endoseal MTA (Maruchi) plus Endocem Zr. Then, we scanned the prepared samples using micro-computed tomographic imaging and performed 3-dimensional reconstruction. The percentage volume of the gap between the canal wall and root-end filling was calculated along with the percentage volume of voids in the filling materials. All data were analyzed using the Mann-Whitney U test. Selected specimens were further observed using scanning electron microscopy.

RESULTS

There were no significant differences in the percentage volumes of the gaps and internal voids between the 2 groups. Both calcium silicate and the calcium silicate-based sealer exhibited good adaptation to the cavity wall.

CONCLUSIONS

The findings of our micro-computed tomographic and scanning electron microscopic analyses suggested that the volume of voids in retrograde filling using a combination of calcium silicate cement and calcium silicate-based sealer was comparable with that in retrograde filling using calcium silicate cement only. Calcium silicate-based sealers could be used in retrograde filling for clinical convenience without harmful effects on the quality of filling.

Clinical and Patient-centered Outcomes of Nonsurgical Root Canal Retreatment in First Molars Using Contemporary Techniques

INTRODUCTION

There have been many recent technical advances in modern endodontics that have the potential to affect treatment outcomes. Reports on treatment outcomes using contemporary techniques are relatively scarce, especially in the field of nonsurgical retreatment. The purpose of this study was to determine the success of nonsurgical root canal retreatment in molars using contemporary endodontic techniques.

METHODS

Sixty-three patients referred for retreatment in first molars were enrolled in the study. The retreatment procedures were performed by endodontic residents using a semistandardized treatment protocol. Patients were followed-up at 6, 12, and 24 months. Treatment outcomes were categorized into healed, healing, or nonhealing based on clinical and radiographic criteria. Healed and healing were considered as successes, and nonhealing was considered a failure. Outcomes were also evaluated using patient-centered criteria that included oral health-related quality of life scores and subjective chewing ability.

RESULTS

Fifty-two of the 63 patients were available for final analysis. Five cases (9.6%) were determined to be nonhealing at the last follow-up with new or persistent periapical lesions. Thirty-seven (71.2%) patients had complete resolution of apical periodontitis, and the remaining 10 (19.2%) remained asymptomatic and showed radiographic evidence of healing. Oral health-related quality of life scores and chewing ability improved significantly over time (P < .05), with the biggest increase observed within the first week of treatment completion.

CONCLUSIONS

This study showed that endodontic retreatment using contemporary techniques significantly improved patients' quality of life and chewing ability over time, with a success rate of 90.4% after 2 years.

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part II: other clinical applications and complications

Mineral trioxide aggregate (MTA) is a dental material used extensively for vital pulp therapies (VPT), protecting scaffolds during regenerative endodontic procedures, apical barriers in teeth with necrotic pulps and open apices, perforation repairs as well as root canal filling and root-end filling during surgical endodontics. A number of bioactive endodontic cements (BECs) have recently been introduced to the market. Most of these materials have calcium and silicate in their compositions; however, bioactivity is a common property of these cements. These materials include the following: BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer, and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA but without the drawbacks. In Part I of this review, the available information on the chemical composition of the materials listed above was reviewed and their applications for VPT was discussed. In this article, the clinical applications of MTA and other BECs will be reviewed for apexification, regenerative endodontics, perforation repair, root canal filling, root-end filling, restorative procedures, periodontal defects and treatment of vertical and horizontal root fractures. In addition, the literature regarding the possible drawbacks of these materials following their clinical applications is reviewed. These drawbacks include their discolouration potential, systemic effects and retreatability following use as a root filling material. Based on selected keywords, all publications were searched regarding the use of MTA as well as BECs for the relevant clinical applications. Numerous publications were found regarding the use of BECs for various endodontic applications. The majority of these investigations compared BECs with MTA. Despite promising results for some materials, the number of publications using BECs for various clinical applications was limited. Furthermore, most studies had several methodological shortcomings and low levels of evidence.