Micro-computed tomographic evaluation on the quality of single-cone obturation using a modified passive-deflation sealer injection needle: an in vitro study

OBJECTIVES

This study aimed to design a modified passive-deflation sealer injection needle and investigate its ability to improve obturation quality of single-cone technique through assessing the distribution of voids in root canals using micro-computed tomography (micro-CT).

MATERIALS AND METHODS

Forty-eight mandibular incisors were divided into eight groups (n = 6), according to the taper of root canal preparation (0.06 or 0.04), the needle used for sealer injection (modified or commercial iRoot SP injection needle), and the obturation method (iRoot SP sealer-only or single-cone obturation). After obturation, each specimen was scanned by micro-CT. The volumetric percentage and distribution of all voids were first analyzed and compared among groups, then the open and closed voids were separately analyzed and compared among single-cone obturation groups.

RESULTS

Compared to commercial needle groups, modified needle groups showed much less voids, especially in the apical root canal part (P < 0.05). Besides, the modified needle groups produced much less open voids than commercial needle groups despite the root canal taper (P < 0.05).

CONCLUSIONS

The modified passive deflation sealer injection needle could effectively improve the quality of single-cone obturation through reducing intra-canal voids, especially open voids throughout the root canal, thus might possibly be developed as an effective intra-canal sealer delivering instrument.

A system for automatic classification of endodontic treatment quality in CBCT

OBJECTIVES

An evaluation of the effectiveness of a new computational system proposed for automatic classification, developed based on a Siamese network combined with Convolutional Neural Networks (CNNs), is presented. It aims to identify endodontic technical errors using Cone Beam Computed Tomography (CBCT). The study also aims to compare the performance of the automatic classification system with that of dentists.

METHODS

One thousand endodontically treated maxillary molars sagittal and coronal reconstructions were evaluated for the quality of the endodontic treatment and the presence of periapical hypodensities by three board-certified dentists and by an oral and maxillofacial radiologist. The proposed classification system was based on a Siamese network combined with EfficientNet B1 or EfficientNet B7 networks. Accuracy, sensivity, precision, specificity, and F1-score values were calculated for automated artificial systems and dentists. Chi-square tests were performed.

RESULTS

The performances were obtained for EfficienteNet B1, EfficientNet B7 and dentists. Regarding accuracy, sensivity and specificity, the best results were obtained with EfficientNet B1. Concerning precision and F1-score, the best results were obtained with EfficientNet B7. The presence of periapical hypodensity lesions was associated with endodontic technical errors. In contrast, the absence of endodontic technical errors was associated with the absence of hypodensity.

CONCLUSIONS

Quality evaluation of the endodontic treatment performed by dentists and by Siamese Network combined with EfficientNet B7 or EfficientNet B1 networks was comparable with a slight superiority for the Siamese Network.

CLINICAL RELEVANCE

CNNs have the potential to be used as a support and standardization tool in assessing endodontic treatment quality in clinical practice.

Physicochemical properties of calcium silicate cement based endodontic sealers

AIM

To mensure the physicochemical properties of three ceramic cement endodontic sealers AH Plus Bioceramic, Bio-C Sealer and Bio-C Sealer Ion+ with an epoxy resin sealer, AH Plus.

MATERIAL AND METHODS

These properties were measured: hardening time (HT), dimensional change (DC), solubility (SL), flow (FL) and radiopacity (RD). The distilled water obtained from the SL test was analyzed with atomic absorption spectrometry. A sample calculation was made considering n = 5 repetitions for each experimental sealer evaluated. Statistical analysis was performed using one-way ANOVA and post hoc Tukey tests (p < 0.05).

RESULTS

For the HT, AH Plus (484 ± 2.76 min) and AH Plus Bioceramic (424 ± 1.23 min) set more slowly than of Bio-C Sealer (370 ± 4.50 min) and Bio-C Sealer Ion+ (380 ± 1.42 min) (p < 0.05). AH Plus Bioceramic (12.56 ± 2.71 %) was more soluble than Bio-C Sealer (6.69 ± 1.67 %), Bio-C Sealer Ion+ (5.67 ± 2.16 %) and AH Plus (0.15 ± 0.01 %) (p < 0.05). AH Plus (0.03 ± 0.01 %) had slight expansion while the cement-based sealers had shrinkage: AH Plus Bioceramic (-1.60 ± 0.63 %) and Bio-C Sealer (-1.38 ± 0.69 %), Bio-C Sealer Ion+ (-5.19 ± 1.23 %) (p < 0.05). Bio-C Sealer Ion+ (59.80 ± 0.86 mm) and Bio-C Sealer (58.60 ± 0.98 mm) had the highest flow compared with AH Plus (56.90 ± 0.56 mm) and AH Plus Bioceramic (49.50 ± 0.63 mm) (p < 0.05). AH Plus (9.17 ± 0.06 mmAl) and AH Plus Bioceramic (8.27 ± 0.84 mmAl) showed radiopacity values when compared with those of Bio-C Sealer (4.90 ± 0.08 mmAl) and Bio-C Sealer Ion+ (4.14 ± 0.05 mmAl) (p > 0.05).

CONCLUSION

Ion release is inhered to these cement-based sealers and this result in calcium ion release.

Assessment of the quality of root canal fillings performed on extracted teeth by undergraduate dental students in a sample from Saudi Arabia

BACKGROUND

The educational process in the field of endodontics commences with preclinical exercises to enhance students' proficiency in cleaning, shaping, and performing root canal fillings. Therefore, this study aimed to radiographically evaluate the technical quality of root canal fillings performed by preclinical students on extracted teeth at the College of Dentistry, University of Ha'il, Saudi Arabia.

METHODS

A total of 788 extracted human teeth received root canal treatment by undergraduate students. The samples were then gathered and radiographically assessed using the three quality criteria of length, density, and taper. The category of root canal fillings was classified as either acceptable or unacceptable. The criteria for evaluating the acceptability of filling quality were defined based on the presence of adequate length, density, and taper. The effectiveness of root canal fillings was also evaluated in relation to the tooth type, sex, and treatment year. The agreement between the examiners was evaluated using Cohen's kappa test, and the relationship between the research variables was determined using the chi-squared test. The significance threshold was set at 0. 05.

RESULTS

The overall quality of root filling was determined to be satisfactory in 532 (67.5%) of 788 endodontically treated extracted teeth. The majority of the research sample (88.1%) had enough length, 89.6% had adequate density, and 86.4% had acceptable taper. The quality of anterior teeth was substantially better than that of posterior teeth (p < 0.001). Our findings showed that the quality of root canals was better in 2022 than it had been in earlier years (p = 0.001). The three RCT quality criteria differed significantly when compared between sexes (p = 0.002).

CONCLUSIONS

The quality of the root canal fillings completed by undergraduate students was rated as acceptable. The findings of the research suggest that the implementation of routine assessments to evaluate the technical competence of undergraduate dental students performing root canal treatments could provide significant insights into the efficacy of the curriculum requirements.

The flow behavior and sealing ability of calcium silicate root canal cement containing dimethyl sulfoxide: An in vitro study

INTRODUCTION

To develop a calcium silicate (CaSi)-based cement containing dimethyl sulfoxide (DMSO) and cement deliver device for new root canal filling technique, and to assess the flow behavior, leakage, and root canal filling quality of CaSi containing DMSO.

METHODS

CaSi containing DMSO (CSC-DMSO) and CaSi containing PEG (CSC-PEG) were prepared, and the flow characteristics of both cements were compared in gypsum and resin channels using a high-speed camera. Eight root canals were obturated by CSC-DMSO or CSC-PEG using a cement delivery device, and root canal filling quality was assessed in terms of filling length using periapical radiographs. The filling length was evaluated by 'apico-coronal extension,' measuring length in reference to apical constriction. Microleakage was measured for thirty human molars that were randomly filled with CSC-DMSO, CSC-PEG, or gutta-percha and AH plus. Preliminary obturation of CSC-DMSO with cement delivery device in human teeth was analyzed in terms of filling length and void, using periapical radiographs. Statistical analysis was performed with the Kruskal Wallis test for simulated root canal fillings and one-way ANOVA for leakage test.

RESULTS

The flow speed of CSC-DMSO reduced in gypsum channels compared to resin channels, but CSC-PEG did not exhibit significant differences in the channels. The median absolute value of apico-coronal extension was significantly lower in CSC-DMSO compared to CSC-PEG (p < 0.05). Microleakage did not statistically differ between the groups (p > 0.05). In the preliminary obturation, the mean apico-coronal extension of CSC-DMSO was -0.297 ± 0.724 mm, while CSC-PEG was not feasible due to excess apical extrusions.

CONCLUSIONS

CSC-DMSO could be considered as an alternative filling material for root canal obturation.

Effectiveness of tricalcium silicate-based cements: Systematic review and meta-analysis

Introduction

Tricalcium silicate-based cements exhibit several beneficial properties for dental health and biocompatibility, which can induce biomineralisation.

Objectives

To assess the sealing ability and intratubular penetration of tricalcium silicate-based sealers using warm and cold obturation techniques.

Materials and Methods

An electronic search was conducted in PubMed, Scopus, and Web of Science databases for endodontically treated teeth with bioceramics and their sealing capacity in root canal obturation published up to February 2023.

Results

Of the 90 articles, 16 met the inclusion criteria, and only 10 were used for the meta-analysis, of which four addressed intratubular penetration, four addressed sealing capacity, and two addressed both variables. In the sealing capacity group, the meta-analysis concluded a standardised mean difference (SMD) of -1.31 in favour of the test group (warm) with a certain nonsignificant trend (p = 0.081); regarding intratubular penetration, the meta-analysis concluded an SMD = 2.34 in favour of the test group (warm) with significantly greater penetration (p = 0.032).

Conclusion

The warm obturation technique introduced significantly greater intratubular penetration than the cold technique, along with a remarkably superior sealing capacity compared to the cold technique, approaching statistical significance.

Reducing apical voids for intra-canal sealer injection using a modified passive deflation needle

The aim of the study was to evaluate the ability of a modified passive deflation needle to reduce the apical voids during the intra-canal iRoot SP sealer injection. A modified passive deflation injection needle was designed. Forty 20°-curved and twenty S-shaped single-canal resin block models were allocated into six groups. Each group was mechanically prepared to #25/04 or #25/06 file; then the root canals were injected with iRoot SP sealer using a modified needle or a normal plastic needle. Radiographs were taken to measure the length of apical void in each specimen. Similarly, twenty single-canal extracted premolars were collected and randomly divided into four groups. Each group was prepared to #25/04 or #25/06 file; then the root canals were injected with iRoot SP sealer using a modified needle or a normal plastic needle. Roots were then scanned using micro-computed tomography (micro-CT), and the volume of voids in root canals was analyzed and compared among groups. Statistical analysis demonstrated that the length and the volumetric percentage of voids were much lower in the modified needle group in both resin block root canal models and extract teeth than the normal plastic needle group (P < 0.05). The modified passive deflation needle can efficiently reduce apical voids during the intra-canal iRoot SP sealer injection.

Assessment of isthmus filling using two obturation techniques performed by students with different levels of clinical experience

Background/purpose

Root canal filling is a necessary skill for dental students and an important aspect of endodontic education. This study aimed to evaluate the effect of students' clinical experiences on isthmus filling using different techniques and sealers.

Materials and methods

One hundred eight three-dimensional-printed resin replicas of isthmus were divided into six groups and either continuous wave of condensation (CWC) or single-cone obturation (SC) was performed. One of three sealers (AH Plus Jet®, GuttaFlow2, iRoot SP) was used together with a size-fitted gutta-percha master cone. All the obturations were completed by students with three different levels of clinical experience including senior postgraduate students (SPS), junior postgraduate students (JPS), and undergraduate students (US). The percentages of filled areas (PFA) at 2, 4, 6, and 8 mm from the apex were analyzed using a light microscope. Data were analyzed using the Mann-Whitney U test or Kruskal-Wallis 1-way ANOVA with Dunn's tests (α = 0.05).

Results

The CWC group exhibited a higher PFA than the SC group (P < 0.05). The PFA was higher in the SPS group than in the JPS group or the US group with CWC (P < 0.05). The three clinical experience groups showed similar PFAs with SC (P > 0.05); however, when using SC with iRoot SP, the PFA was higher than with either of the other two sealers (P < 0.05).

Conclusion

CWC was found to be technique-sensitive and required clinical training. With SC, clinical experience did not improve the quality of isthmus filling without additional training. CWC was superior to SC for type IV isthmuses. When using SC, better filling quality was obtained with a bioceramic sealer.

Comparative Evaluation of Single Rotary File System and Sequential Multi-file Rotary Systems on Time for Biomechanical Preparation and Obturation Quality in Single-visit Pulpectomy Protocol: A Double-blind Randomized Clinical Trial

Background

Single-visit pulpectomy (SVP) protocol with rotary files is highly recommended for the treatment of teeth with irreversible pulpitis. Various rotary endodontic files specially designed for use in the pediatric population are available. The aim is to clinically assess the parameters related to the time required for biomechanical preparation (TBMP) and quality of filling using a single file system vs a sequential multi-file system in infected primary mandibular molars.

Materials and methods

A total of 45 infected primary molars were allocated to three groups (two experimental groups (n = 15) and a control group. The first experimental group was instrumented using NiTi K-Flex files, the second group with a single file rotary system with variably variable (VV) taper, and the third with a sequential multi-file system with constant taper. Biomechanical preparation time was recorded and standardized digital radiograph (RVG) were taken pre- and postinstrumentation. The data recorded was sent for statistical analysis.

Conclusion

There is a substantial reduction of TBMP in primary molars using single file VV taper and multi-sequential file constant taper. Obturation time for all three file systems was comparable and there were no differences between the three file systems used (p > 0.05). Multi-sequential file constant taper files showed a higher probability of optimal obturations and minimal voids followed by NiTi "K-Flex" files and single file system but the difference was nonsignificant (p > 0.05). However, using a rotary in primary teeth results in better canal shape, and less TBMP leading to a better quality of treatment in less time.

How to cite this article

Shetty B, Singh R, Patil V, et al. Comparative Evaluation of Single Rotary File System and Sequential Multi-file Rotary Systems on Time for Biomechanical Preparation and Obturation Quality in Single-visit Pulpectomy Protocol: A Double-blind Randomized Clinical Trial. Int J Clin Pediatr Dent 2023;16(S-3):S247-S252.

Postoperative pain after root canal filling with bioceramic sealers: a systematic review and meta-analysis of randomized clinical trials

The aim of this systematic review and meta-analysis (SRM) was to assess postoperative pain (PP) after endodontic treatment with bioceramic root canal sealer compared to AH Plus® sealer. This SRM was carried out in accordance with the items on the PRISMA 2020 checklist and Cochrane guidelines and registered in PROSPERO (CRD42021259283). Only randomized clinical trials (RCTs) were included. Meta-analysis was conducted using R software, the standardized means difference (SMD) measure of effect was calculated for quantitative variables, and the odds ratio (OR) for binary variables. The Cochrane tool (RoB 2.0) was used to assess the risk of bias, and the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to assess the quality of evidence. Qualitative and quantitative analysis included 18 and 17 studies, respectively. For quantitative variables, the bioceramic root canal sealer presented less occurrence of postoperative pain than the AH Plus® sealer in 24 h (SMD - 0.17 [- 0.34; - 0.01], p = 0.0340). For binary variables, there was no difference observed between the sealers evaluated, except for sealer extrusion where the bioceramic group had lower post-filling material extrusion (OR 0.52 [0.32; 0.84], p = 0.007). Regarding the risk of bias analysis, low risk was observed for most domains, except allocation that was considered unclear, while the certainty of evidence ranged from moderate to low. The results showed that bioceramics sealers reduced postoperative endodontic pain only after 24 h and showed less sealer extrusion compared to the AH Plus® sealer. However, more robust and standardized clinical trials are needed to confirm the results with less heterogeneity and higher quality of evidence.

A critical review of the material properties guiding the clinician's choice of root canal sealers

OBJECTIVES

The introduction of hydraulic cement sealers has increased the popularity of single cone obturation where the chemistry and properties of hydraulic cement sealers are crucial. This article has investigated the materials present on the market by reviewing the chemistry aiming at understanding whether these materials are optimized or have been tested appropriately.

METHODOLOGY

A market search on materials called bioceramic and hydraulic sealers was undertaken. The safety data sheet and manufacturer details for every material were searched and the components were checked. The literature was searched for information about the properties of these materials based on their composition.

RESULTS

The safety data sheets and manufacturer details were imprecise with some manufacturers providing little detail on composition. From the publications reviewed, it is apparent that the materials used clinically are not optimized, and there is little evidence that the material chemistry and presentation aid the clinical technique in any way.

CONCLUSIONS

There has been a rapid increase in materials identifying as bioceramics on the market. These materials have diverse chemistries, and some of the constituents are not declared. This may affect the clinical performance of these materials.

CLINICAL SIGNIFICANCE

Smart materials developed on the clinical need which are appropriately tested are necessary for a paradigm shift in root canal obturation. It is important to use reputable materials that have been adequately researched in clinical practice.

Evaluation of the push-out bond strength of an adjustable fiberglass post system to an endodontically treated oval root canal

To evaluate the push-out bond strength of the adjustable fiberglass post system to dentin. Twenty maxillary canine roots were endodontically treated and divided into two groups (n=10): conventional fiberglass posts (CFPs) and with single adjustable post (SAP) system. Two slices of each third were subjected to the push-out and failure pattern test and the most apical slice was subjected to analysis of the adhesive interface by scanning electron microscopy (SEM). Data were analyzed by the three-way analysis of variance, Tukey, and Friedman tests, and linear regression (α=0.05). The results showed higher push-out bond strength in the initial time interval for SAP (10.3±5.3, p<0.01). After 6 months, there was reduction in push-out bond strength for both (p<0.001). A higher percentage of adhesive and cohesive failures to dentin. After 6 months areas of maladaptation were noted (p=0.000). The SAP is completed to the promissory root canal in relation to alternative CFP.

Prevalence and morphological analysis of dens invaginatus in anterior teeth using cone beam computed tomography: A systematic review and meta-analysis

OBJECTIVES

To evaluate the prevalence and morphological characteristics of DI using CBCT.

METHODS

A literature search was performed in PubMed, Embase, Scopus, and Web of Science. Inclusion criteria were randomized clinical trials, cross-sectional studies, and prospective and retrospective cohort studies evaluating the morphological characteristics of DI in anterior teeth using CBCT. Three reviewer authors independently screened the studies, applied the eligibility criteria, assessed the risk of bias, and extracted until September (2022). The risk of bias was evaluated using the Joanna Briggs Institute criteria. Meta-analyses of proportions were used for estimate the prevalence DI according to factors at participant and tooth levels.

RESULTS

Six studies were included in the meta-analysis. Among 7373 individuals, a prevalence of 7.45 % of DI was observed (n = 258; τ2 = 0.0096; CI of 4.51-11.3; p < 0.05), with no significant influence of sex. Regarding laterality, unilateral DI showed higher mean prevalence (4.30 %; CI of 2.03-7.33). Among the 382 anterior teeth with DI (0.72 %), the most affected tooth was the upper lateral incisor (5.12 %; n = 329; CI of 2.35-8.86; p < 0.001), type I was the most prevalent (0.59 %; CI of 0.24-1.08) and the presence of open apex and periradicular pathology ranged from 4.3 % to 22.72 % and 3.5-77.92 %, respectively.

CONCLUSIONS

The prevalence of individuals with dens invaginatus was 7.45 %, the most affect tooth was the upper lateral incisor with a prevalence of 5.12 % unilaterally and type I was the most prevalent morphology.

Effect of endodontic sealer on postoperative pain: a network meta-analysis

This systematic review and network meta-analysis aimed to answer the following focused research question: "Does the type of endodontic sealer affect the postoperative pain in patients who received endodontic treatment?" Different databases and grey literature were surveyed. Only one randomized controlled trial were included. The risk of bias in the studies was evaluated by using the Cochrane Collaboration's tool. A random-effects meta-analysis was conducted to compare the risk and intensity of postoperative pain. The quality of the body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. Out of 11,601 studies, 15 remained for qualitative analyses and 12 for meta-analysis. Seven studies were classified at high risk of bias, and 8 studies raised some concerns. No significant differences between the endodontic materials were observed in the direct comparisons, both in risk and in intensity of postoperative pain (pairwise comparisons with 2 studies: I² = 0%; p > 0.05 and 8 studies: I² = 23%; p > 0.05, respectively). The certainty of the evidence was graded as low or moderate. There was no difference in the risk and intensity of postoperative pain after filling with different endodontic sealers. Further systematic reviews should be conducted.

Trial Registration

PROSPERO Identifier: CRD42020215314.

Marginal gaps and voids using two warm compaction techniques and different sealers: a micro-CT study

OBJECTIVE

To assess the percentage of marginal gaps and voids in oval-shaped canals obturated by using two warm compaction techniques with a Bio-C sealer and AH Plus Jet.

MATERIALS AND METHODS

Forty canines with oval canals were scanned by microcomputed tomography (micro-CT), and root canal preparation was performed with an XP-endo Shaper system and irrigated with 5.25% sodium hypochlorite. Then, the specimens were paired into four groups (n=10) according to the root canal filling technique and endodontic sealer: Bio-C sealer and continuous wave of condensation, Bio-C sealer and Tagger's hybrid, AH Plus Jet and continuous wave of condensation, and AH Plus Jet and Tagger's hybrid. After root canal filling, a new scan was performed. The percentage of marginal gaps and voids was calculated with the ImageJ software, and the data were analyzed statistically using two-way ANOVA and Tukey tests, with a significance level of 5%.

RESULTS

The percentage of marginal gaps was significantly lower in the Bio-C sealer than in AH Plus Jet (p=0.021) regardless of the technique. However, no difference was found in the percentage of voids between root canal filling techniques and the endodontic sealer (p>0.05).

CONCLUSION

Both sealers and techniques demonstrated good quality of root canal filling. However, the use of the Bio-C sealer enhanced the filling ability by reducing marginal gaps, regardless of the root canal filling technique.

CLINICAL RELEVANCE

This study highlights the better performance of the Bio-C sealer in the quality of the root canal filling, reducing marginal gaps when compared to AH Plus Jet independent of the technique.

Influence of relative positions of the heat carrier and lateral canal opening on gutta-percha obturation of lateral canals in a three-dimensional-printed model

Background/purpose

Effective filling of the lateral canals is of great significance in successful root canal treatment, but it is generally being challenging. This study aimed to evaluate the influence of relative positions of the heat carrier and lateral canal opening on gutta-percha obturation of lateral canals in a three-dimensional (3D)-printed model.

Materials and methods

Thermal conductivity and real-time temperature transmission of gutta-percha were investigated using laser flash and thermal infrared analyses. 3D-printed root canal models with lateral canals at 1, 3, and 5 mm from the apex were fabricated, and different relative positions of the heat carrier were tested. The obturation process was recorded on video, and the obturation depth of the lateral canals was observed using X-ray micro-computed tomography.

Results

Gutta-percha showed low thermal conductivity of 1.07 W/(m·K), and heating increased the temperature of gutta-percha above 60 °C only within 1 mm beyond the heat carrier tip. For lateral canals at 1 and 3 mm from the apex, gutta-percha penetrated further with deeper penetration of the heat carrier (P < 0.05). For 5-mm lateral canals, the heat carrier was always at apical level and the gutta-percha obturation depth was more at 2 mm apically than at 3 or 4 mm (P < 0.05).

Conclusion

Gutta-percha is a poor thermal conductor. The position of the heat carrier in relation to the lateral canal opening affects obturation depth. Only when the heat carrier reaches or passes the lateral canal opening can gutta-percha penetrate a lateral canal.

Effect of using calcium-silicate and silicone based root canal sealers in bulk or with main core material on bond strength

Background

The purpose of this study was to assess the push-out bond strength of calcium-silicate and silicone based root canal sealers in bulk and with main cone.

Methods

Roots (n=48) randomly divided into 4 groups (n=12) according to the obturation protocol; (1) iRoot SP in bulk; (2) iRoot SP with gutta-percha; (3) GuttaFlow Bioseal in bulk; (4) GuttaFlow Bioseal with gutta-percha. Six horizontal sections were obtained from each root (n=72). Effect of sealers on bond strength was statistically significant (P<0.05).

Results

Highest mean value was obtained in iRoot-Bulk group and lowest in GuttaFlow Bioseal-GP group. Both iRoot SP groups had significantly higher bond strength values than both GuttaFlow Bioseal groups (P<0.05). There was no significant difference between iRoot-GP and iRoot-Bulk groups (P=0.603) also GuttaFlow Bioseal-GP and GuttaFlow Bioseal-Bulk groups (P=0.684).

Conclusion

Based on findings, using calcium silicate-based sealer in bulk can be also suitable in clinical practice.

The impact of provisional intraradicular retainers cementation with temporary methacrylate-based resin in the bond strength of glass fiber posts to root dentin

Chemical composition of temporary cements interferes in the bond strength and quality of the bond interface of glass fiber posts to root dentin. The aim of the present study was to evaluate the influence of different temporary cements on the bond strength of fiberglass posts and resin cement. Thirty-two maxillary central incisor roots were standardized at 15 mm length. The root canals were prepared with Reciproc R50 and filled with a R50 single cone and AH Plus. Ten mm of filling material was removed with a heated Schilder condenser, leaving 5 mm of apical filling material. The roots were randomly distributed into 4 groups (n = 8). In the control group, the root canal was prepared with a standard drill according to the post diameter (DC #1, FGM, Joinville, Brazil), irrigated with 5 mL of distilled water and immediately received the fiberglass post cemented with self-adhesive resin cement. For the other groups, cores were made with temporary intraradicular retainers cemented with different temporary cements: methacrylate-based resin (Bifix Temp - Voco), calcium hydroxide-based (Provicol - Voco) and zinc oxide-based - eugenol-free (Relyx Temp NE - 3M). After 7 days, mechanical removal of the temporary retainers, preparation, irrigation of the root canal and cementation of the fiberglass post were performed, following the same protocol that had been performed in the control group. The roots were sectioned to obtain 3 slices per root third. The most cervical section of each third was used for the push-out test and failure pattern analysis, while the most apical section was subjected to analysis of the adhesive interface by scanning electron microscopy (SEM). The BS data were compared between groups using the two-way ANOVA and Tukey post-test. The failure pattern results were expressed in percentage and compared between groups using the chi-square test and the material adaptation data at the bond interface were evaluated using the Kruskal-Wallis and Dwass-Steel-Critchlow-Fligner tests. The results showed higher BS in the cervical third, with a higher value in the control group (10.8 ± 0.94) and Bifix Temp group (9.78 ± 0.71), with no statistically significant difference between these groups (P > .05). The middle and apical thirds showed no statistically significant difference (P > .05). As regards the type of failure, a higher percentage of mixed adhesive failures was observed for all groups. Analysis of the adhesive interface by SEM showed that the temporary cement Bifix Temp showed greater adaptation at the bond interface. It was concluded that the methacrylate-based resin temporary cement showed the highest bond strength values and best adaptation to root dentin than the zinc oxide-based and calcium hydroxide-based temporary cements.

Comparison of the effect of post space preparation time on the apical seal of two different sealers

BACKGROUND

The present study compared the effect of post space preparation time on the apical seal of two different sealers.

METHODS

In the in vitro study, 94 central incisors were used. After the samples' root canal preparation, they were randomly assigned to four experimental groups (n = 21). The samples in groups 1 and 2 were obturated with AH Plus sealer, gutta-percha, and in groups 3 and 4 with Endoseal MTA bioceramic sealer and single cone technique. The post spaces in groups 1 and 3 were prepared immediately and in groups 2 and 4 with a delay. The samples were evaluated at 7-, 30-, and 90-day intervals for apical microleakage using the fluid filtration technique. The data were analyzed with SPSS 25, using three-way ANOVA and independent t-test.

RESULTS

The apical microleakage in groups 3 and 4, obturated with Endoseal MTA bioceramic sealer and prepared immediately and after a delay, respectively, was not significantly different between the interval times. In group 2, obturated with AH Plus sealer and prepared for post space with a delay, the apical microleakage was significantly less than all the other groups. Group 1, obturated with AH Plus sealer and prepared for post space immediately, exhibited the least microleakage after seven days, but its microleakage increased over time to reach the level of groups 3 and 4.

CONCLUSION

According to the results, the apical microleakage in the AH + sealer group and the delayed post-space preparation method, was significantly less than all the other groups over time.

Effect of obturation technique on penetration of calcium silicate-based sealer into dentinal tubules after endodontic retreatment of mandibular premolars

OBJECTIVE

Confocal laser scanning microscopy (CLSM) was used to investigate the penetration of endodontic sealers into the dentinal tubules after retreatment using two different obturation techniques.

MATERIALS AND METHODS

Thirty mandibular premolars were prepared up to instrument F3 (ProTaper Universal, Dentsply) and filled with Endofill using the single cone technique. The canals were retreated using Mtwo instruments. Reobturation was performed with the Bio-C sealer mixed with a fluorophore dye (Fluo-3) using either the lateral condensation technique (group LC) or the single cone technique (group SC) (n = 15). Teeth were sectioned 2, 4, and 6 mm from the apex and analyzed with CLSM to assess the penetration of the sealer into the canal perimeter and the maximum depth of penetration of the sealer into the dentinal tubules. Data were analyzed using ANOVA and the Student-t and Holm-Sidak tests.

RESULTS

In the apical segment, the penetrated perimeter was significantly higher in the LC group than in the SC group (p < 0.05); no significant difference was found in the middle and cervical segments (p > 0.05). In terms of penetration depth, no significant differences were found for any of the segments studied (p > 0.05).

CONCLUSION

The LC technique promoted a higher percentage of canal circumference penetrated by the sealer than the SC technique in the apical segment after endodontic retreatment.

CLINICAL RELEVANCE

CLSM demonstrated that the LC technique promoted a higher percentage of canal perimeter penetrated by the Bio-C sealer than the SC technique in the apical segment of mandibular premolars after retreatment.

Postoperative pain intensity and incidence following single visit root canal treatment with different obturation techniques: a randomized clinical trial

Background

There are few studies in the literature about the effect of obturation techniques on postoperative pain. Besides, GuttaFlow2 was used for the first time in this study regarding postoperative pain. This study aimed to compare the postoperative pain levels and incidence following single-visit root canal treatment with different canal filling techniques; cold lateral compaction (CLC), thermoplasticised solid-core carrier (GuttaCore) based filling and cold free-flow compaction (GuttaFlow2) technique.

Methods

The patients (n = 93) having single-rooted teeth with a single canal diagnosed with asymptomatic irreversible pulpitis or single-rooted vital teeth with a single canal requiring endodontic treatment because of prosthetic reasons were enrolled in this study. Patients were randomized into three groups (n = 31) according to the obturation technique. A single operator performed all the treatments in a single visit. Data on obturation levels, postoperative pain and analgesic intake frequency were recorded at postoperative 6, 12 and 24 h and daily afterward until the 7^th day. Postoperative pain was measured by visual analogue scale (VAS). The date were statistically analyzed with chi-squared tests (for the analyses of the categorical data), the nonparametric Kruskal-Wallis test (for the comparisons of VAS score) and with the Friedman test (for the assessments of the changes in VAS scores over time).

Results

The GuttaCore group recorded the higher pain levels, except first 12 h, on the other hand, the GuttaFlow2 group recorded the lower pain levels at all time periods. Significant differences occurred among the groups during the first 4 days (p < 0.05), except at 12 h (p = 0.054). The patients in the CLC and GuttaFlow2 groups did not need to use the prescribed analgesic; however, one patient in the GuttaCore group used it once.

Conclusions

Postoperative pain levels following root canal therapy were affected by the obturation technique especially first 4 days following obturation.

Comparative evaluation of different irrigating and irrigant activation system in removal of gutta-percha/sealer during retreatment: An in vitro Micro-CT study

Background

The aim of the study was to compare the efficacy of different irrigation and irrigant activation system used as an adjuvant to retreatment rotary files in removal of gutta-percha and sealer from endodontic retreatment using Micro-CT.

Method

64 extracted permanent maxillary central incisor teeth with single canal, were collected and decoronated to standard length of 16 mm. Instrumentation was done using rotary files and obturation was performed using GuttaCore and AH plus sealer. After setting of sealer, initial removal of filling material was performed using ProTaper universal retreatment files (D1, D2, D3). All 64 sample were randomised into four groups (n = 16) Group1: Endodontic syringe irrigation, Group 2: Passive Ultasonic Irrigation (PUI), Group 3: EndoActivator, and Group 4: EndoVac. Micro-CT scanning was performed after obturation, initial removal of filling material by retreatment file and after using experimental protocols of each group, and volume of remaining filling material was calculated using Dolphin software. Statistical analysis performed with one-way ANOVA followed by Tukey's post hoc.

Results

A significant reduction in the volume of residual obturation material were found between each group. PUI was superior to the sonic (EndoActivator), negative pressure irrigation technique (EndoVac) and positive pressure irrigation at the coronal, middle third and apical third of the root canal. However, none of the supplementary techniques were able to completely remove the residual obturation material.

Conclusion

PUI and EndoActivator were found better in remaining filling material removal, demonstrating clinically useful as supplementary technique in removing remaining obturation material during endodontic retreatment.

Is the quality of root canal filling obtained by cone-beam computed tomography associated with periapical lesions? A systematic review and meta-analysis

AIM

To evaluate the influence of root canal filling quality on periapical lesion status using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

The bibliographic search was conducted in electronic databases of PubMed, Embase, Scopus, and Web of Science without restrictions related to the year of publication and language. Inclusion criteria were prospective or retrospective cohort studies that followed periapical pathosis for, at least, 1 year. Three reviewers independently evaluated the eligibility for inclusion, extracted data, and assessed the risk of bias. The quality of the studies was based on the Newcastle-Ottawa Scale. This meta-analysis was performed to evaluate the quality of treatment by the homogeneity and apical extension of the filling.

RESULTS

Of the 1179 studies initially recovered, six cohort studies were included, out of which four were considered with a low risk of bias. The results showed that the absence of gaps in the filling reduced the chance of unhealed periapical lesions by 2.39 times (RR = 2.39; 95% CI: 1.62-3.53; p < 0.00001; I² = 55%). An apical filling extension of 0-2 mm below the apex also contributed significantly to the absence of unhealed periapical lesions (RR = 1.49; 95% CI: 1.15-1.94; p = 0.003; I² = 2%).

CONCLUSION

The homogeneity and apical extension of the filling influenced the presence of unhealed periapical lesions in endodontically treated teeth evaluated using CBCT.

CLINICAL RELEVANCE

Apical extension of the filling ranging between 0 and 2 mm short of the apical foramen and the homogeneity of the filling without gaps are directly related to the success rate of root canal treatment.

Unravelling the effects of ibuprofen-acetaminophen infused copper-bioglass towards the creation of root canal sealant

Impact towards the tuneable characteristics of bioactive glasses (BAG) has been explored; as there is no root canal sealant till date with ideal characteristics competent enough to manoeuvre the perplexing root canal architecture. Combeite, calcite and traces of cuprorivaite crystalline phases were validated for material formation, in which Cu 2P [XPS] peak authenticating the presence of copper in bioglass network (Cu-BAG). Spherical and platelet-like morphologies were observed and the grain size of Cu-BAG (~100 nm) was lesser as compared to BAG (~ 1 µm). These particle distributions impacted the porosity, and dominant non-bridging oxygens in Cu-BAG influences ionic dissolution, which subsequently enhanced the mineralization. These bioactive materials were loaded with acetaminophen and ibuprofen, corresponding organic moieties was confirmed through FT-IR. These drugs loaded bioactive materials exhibited tremendous anti-inflammatory and anti-microbial behavior with better sealing ability. Drug loaded bioglass paste filled in biomechanically prepared root canal was estimated for sealing potential, mineralization, micro leakage, and fracture resistance properties. Hydroxyl apatite growth was noted on the sealants, flower like protuberance confirmed the sealing potential of the prepared material. Bioglass exhibited promising characteristics required in a root canal sealant. This investigation is a step further towards tailoring the properties of bioactive materials as promising candidates in root canal obturation and thereof.

[Application of cold flowable gutta-percha in root canal obturation after apexification]

OBJECTIVE

To evaluate the clinical effect of root canal obturation therapy using cold flowable gutta-percha on young permanent teeth after apexification.

METHODS

Ninety cases of young permanent teeth with pulp necrosis or periapical periodontitis treated by apexification were randomly divided into two groups. The cases in each group were divided into single root canal and multiple root canal according to the number of the root canal, and divided into classifications Ⅰ, and Ⅱ/Ⅲ/Ⅳ according to Frank's classification of root development after apexification. Cold flowable gutta-percha and warm gutta-percha obturation techniques were used for root canal obturation of the two groups. The operation time was recorded, and the patients' therapy pain degree was evaluated by visual analog scale (VAS) immediately after operation. Periapical X-ray was performed after operation to evaluate the effect of the root canal filling. The total length of the root was divided into equal three parts on the X-ray film, and three-dimensional tightness of the apical, middle, and coronal region of the root canals were statistically analyzed respectively. Clinical examinations and X-ray examination were performed 6 and 12 months after the operation to evaluate the treatment success rate.

RESULTS

The operation time of cold flowable gutta-percha group was significantly lower than that of the control group, which were 51 s and 74 s (P < 0.05); The percentages of pain and discomfort in the two groups were 26.67% and 40.00%, respectively. There were two cases of underfilling and no overfilling in both groups. The percentages of proper filling and tight three-dimensional obturation in the experimental and control groups were 71.11% and 60.00% respectively; and the percentages of tight three-dimensional obturation in the apical third areas were 86.67% and 66.67%, the difference was significant (P < 0.05). There was no significant difference in the three-dimensional tightness between the two groups in the middle and coronal third areas. The percentages of tight three-dimensional obturation in classification Ⅰ groups were 86.67%, 83.33%, 93.33% and 76.67%, 90.00%, 96.67% in experimental and control group, respectively; The percentages of classification Ⅱ/Ⅲ/Ⅳ groups were 86.67%, 86.67%, 100.00% and 46.67%, 86.67%, 100.00%, respectively, and the difference was significant (P < 0.05). There were no apical lesions that occurred in either group during the one-year review period.

CONCLUSION

The application of cold flowable gutta-percha on young permanent teeth root canal obturation after apexification can achieve good obturation effect. The root obturation effect in the apical third area is significantly better than that of warm gutta-percha obturation techniques. Cold flowable gutta-percha can shorten the clinical treatment time and ameliorate the patients' therapy comfort.

Comparison of bacterial microleakage of three bioactive endodontic sealers in simulated underwater diving and aviation conditions

BACKGROUND

Bacterial microleakage is an important cause of apical periodontitis and endodontic treatment failure. This study aimed to assess the bacterial microleakage of nano-mineral trioxide aggregate (nano-MTA) as a sealer, Endoseal MTA, and GuttaFlow Bioseal sealers in atmospheric pressure, and simulated underwater diving and aviation conditions.

METHODS

In this in vitro, experimental study, 180 extracted single-rooted teeth were cleaned and shaped, and were then randomly divided into three groups for single-cone obturation using Endoseal MTA, GuttaFlow Bioseal, or nano-MTA as a sealer. Each group was then randomly divided into three subgroups, and subjected to ambient atmospheric pressure, 2 atm pressure (to simulate underwater diving), and 0.5 atm pressure (to simulate aviation) using a custom-made pressure chamber. The teeth then underwent microbial leakage test using Streptococcus mutans (S. mutans), and the percentage of samples showing microleakage was recorded for up to 1 month, and analyzed using the Chi-square test.

RESULTS

The three sealer groups were significantly different regarding bacterial microleakage (P < 0.05). The nano-MTA group showed significantly higher microleakage after 15 days than the other two groups (P = 0.006). The effect of pressure on bacterial microleakage was not significant in any sealer group (P > 0.05).

CONCLUSION

Within the limitations of this in vitro study, it may be concluded that single-cone obturation technique using nano-MTA as a sealer results in lower resistance to bacterial microleakage compared with the use of GuttaFlow Bioseal, and Endoseal MTA. Pressure changes in simulated underwater diving and aviation conditions had no significant effect on bacterial microleakage. Trial Registration Number This is not a human subject research.

[Progress in the diagnosis and treatment strategies of caries-derived dental pulp diseases]

Caries-derived dental pulp diseases are characterized with high incidence and serious endangerment. Considering the complexity of the pulpal infection and the limitation of the pulp self-repairing capability, it is still an urgent problem that how to eradicate infection and to promote tissue regeneration subsequently for dental clinicians. This review discusses and prospects on the pathogenesis, diagnosis and treatment strategies of caries-derived dental pulp diseases, so as to provid a reference on diagnosis and treatment of such diseases for the clinicians.

A 12-month follow-up of primary and secondary root canal treatment in teeth obturated with a hydraulic sealer

Objectives

This randomized, controlled, pilot study assessed the outcome of non-surgical primary/secondary root canal treatments either with a novel bioactive sealer and the single-cone technique or with gutta-percha, zinc oxide-eugenol sealer (ZOE), and warm vertical compaction.

Materials and methods

Sixty-nine patients were randomly divided into two groups that were treated using the single-cone technique with BioRoot^TM RCS (Septodont) (BIO group) or warm vertical compaction with gutta-percha and ZOE sealer (PCS group). Two subsamples (BIOAP and PCSAP) comprised the cases with apical periodontitis. Treatment was undertaken by four residents using a standardized instrumentation and disinfection protocol. The periapical index (PAI) was recorded, and clinical and radiographic follow-up performed at 1, 3, 6, and 12 months. Treatment success was assessed according to “periapical healing” and “tooth survival”. The test for the equality of proportions, t tests for the equality of means, and non-parametric K-sample tests for the equality of medians were applied when appropriate.

Results

The survival rate was similar in the BIO and PCS (p = 0.4074) and the BIOAP and PCSAP groups (p = 0.9114). The success rate was higher in the BIO groups, but not statistically significant (p = 0.0735). In both BIOAP and PCSAP groups, a progressive decrease in the PAI was observed.

Conclusion

At 12 months, both techniques showed reliable results. Further studies and longer follow-ups are needed.

Clinical relevance

This study documents the feasibility of using a bioactive sealer in conjunction with the single-cone technique to obturate the root canal and obtaining a predictable outcome.

Trial registration

ClinicalTrials.gov Identifie: NCT04249206

Micro-computed tomographic evaluation of a new system for root canal filling using calcium silicate-based root canal sealers

Objectives

This study evaluated by using micro-computed tomography (micro-CT) the filling ability and sealer apical extrusion promoted by a new Sealer Injection System (SIS; Angelus) with side openings needle, in comparison with the conventional injection system, associated with a new ready-to-use calcium silicate-based sealer (Bio-C Sealer).

Materials and Methods

Acrylic resin models containing a main curved artificial canal and 3 simulated lateral canals in apical, middle and cervical thirds were used. The main root canals were prepared using a rotary system up to size 35.05. The canals were filled with Bio-C sealer by using a single cone technique and the conventional delivery system or SIS. Samples were scanned in micro-CT. The percentage of voids throughout the entire extension of the main root canal and in each third of the lateral canals, besides the apical extrusion of the sealer was calculated. Data were submitted to t-test (p < 0.05).

Results

There was no difference between both systems in the main root canals filling. Although the volume percentage of voids was similar in the apical and middle thirds of lateral canals, SIS had the greatest filling ability of the cervical third lateral canal. Moreover, the conventional system showed the highest apical extrusion of the sealer.

Conclusions

The conventional and SIS obturation systems had an appropriate filling ability of the main root canal. SIS had the best filling of the cervical third of the lateral canals, besides lower sealer apical extrusion, suggesting its clinical indication.

Thermal behavior and viscoelastic properties of gutta-percha used for back-filling the root canal

BACKGROUND/PURPOSE

In clinical operations, qualitative differences in the texture and operational feeling of the regular type and soft type back-filled gutta-percha are readily discernible. This study aimed to investigate and compare the thermal behavior and physical properties of the two gutta-percha materials.

MATERIALS AND METHODS

The chemical compositions of regular and soft type Gutta-Percha Obturator® pellets were examined via energy dispersive X-ray spectroscopy. The thermal behaviors of the pellets during heating and cooling were evaluated using a differential scanning calorimeter. Finally, the viscoelastic properties of the two materials during cooling were assessed using a modular compact rheometer.

RESULTS

The soft type gutta-percha contained a greater atomic percentage of zinc than the regular type material. In addition, the soft type gutta-percha exhibited exothermic peaks during cooling, whereas the regular type gutta-percha did not. The two materials exhibited different viscoelastic behaviors under cooling. In particular, the rate of change of the loss factor for the soft type gutta-percha was more than that of the regular type gutta-percha at temperature lower than 80°C.

CONCLUSION

The soft type gutta-percha underwent significant crystallization during cooling, and therefore exhibited pronounced volume shrinkage. Furthermore, the soft type gutta-percha underwent a greater rate of change in viscoelasticity under cooling than the regular type gutta-percha, and exhibited poorer physical stability. Consequently, in the back-packing procedure, soft type gutta-percha must be compacted more often over time than regular type gutta-percha to ensure the same quality of root canal obturation.

A micro-computed tomographic study of remaining filling materials of two bioceramic sealers and epoxy resin sealer after retreatment

Objective

This study evaluated the presence of residual root canal filling material after retreatment using micro-computed tomography (micro-CT).

Materials and Methods

Extracted human teeth (single- and double-rooted, n = 21/each; C-shaped, n = 15) were prepared with ProFile and randomly assigned to three subgroups for obturation with gutta-percha and three different sealers (EndoSeal MTA, EndoSequence BC sealer, and AH Plus). After 10 days, the filling material was removed and the root canals were instrumented one size up from the previous master apical file size. The teeth were scanned using micro-CT before and after retreatment. The percentage of remaining filling material after retreatment was calculated at the coronal, middle, and apical thirds. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni post hoc correction.

Results

The tested sealers showed no significant differences in the percentage of remaining filling material in single- and double-rooted teeth, although EndoSeal MTA showed the highest value in C-shaped roots (p < 0.05). The percentage of remaining filling material of AH Plus and EndoSeal MTA was significantly higher in C-shaped roots than in single- or double-roots (p < 0.05), while that of BC sealer was similar across all root types. EndoSeal MTA showed the highest values at the apical thirds of single- and double-roots (p < 0.05); otherwise, no significant differences were observed among the coronal, middle, and apical thirds.

Conclusions

Within the limitations of this study, a large amount of EndoSeal MTA remained after retreatment, especially in C-shaped root canals.

Bacterial leakage and micro-computed tomography evaluation in round-shaped canals obturated with bioceramic cone and sealer using matched single cone technique

OBJECTIVES

To evaluate sealing ability of root canals obturated with bioceramic-impregnated gutta percha cone (BCC) or gutta percha (GP), with bioceramic sealer (BCS) or AH Plus (AH; Dentsply-Maillefer), in roundly-prepared canals using matched single-cone technique, based on bacterial leakage test, and to analyze obturation quality using micro-computed tomography (CT) analysis.

MATERIALS AND METHODS

Ninety-two distobuccal roots of maxillary molars were prepared using nickel-titanium files to apical size 40/0.06. The roots were divided into 4 groups (n = 20) that were obturated with a master cone and sealer: GP/AH, BCC/AH, GP/BCS, and BCC/BCS. Bacterial leakage model using Enterococcus faecalis was used to evaluate sealing ability for 60-day period. Obturated samples from each group (n = 4) were analyzed using micro-CT.

RESULTS

All groups showed bacterial leakage at 20%-45% of samples with mean leakage times of 42-52 days. There were no significant differences in bacterial leakage among the groups. Micro-CT showed minimal gaps and voids in all groups at less than 1%.

CONCLUSIONS

In roundly-prepared canals, the single cone obturation with BCC/BCS was comparable to GP/AH for bacterial leakage at 60 days.

Comparative evaluation of the vertical fracture resistance of endodontically treated roots filled with Gutta-percha and Resilon: a meta-analysis of in vitro studies

Background

Teeth treated endodontically are more susceptible to vertical root fracture (VRF). Some studies have suggested that obturating the root canals with Gutta-percha or Resilon can reinforce endodontically treated teeth, but a few others have presented conflicting results. These inconsistent results cannot guide clinicians in determining clinical approaches. The objective of this meta-analysis is to evaluate and compare the vertical fracture resistance of endodontically treated root canals obturated with Gutta-percha/AH plus and the Resilon system.

Methods

Comprehensive literature searches were performed in the PubMed, Cochrane Library, ScienceDirect, Web of Science and Embase databases. The titles and abstracts of all of the retrieved articles were independently assessed by two authors according to predefined selection criteria. Data in the included articles were independently extracted. Statistical analyses were conducted using Review Manager 5.3 and Stata 12.0 software. The pooled standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated for the outcome indicators. The level of statistical significance was set at p < 0.05. The Cochran Q test (I² test) was used to test for heterogeneity among studies.

Results

Fourteen randomized controlled in vitro trials were included in the meta-analysis. The results demonstrated that the vertical root fracture resistance of unprepared and unfilled roots was significantly higher than that of roots obturated with Gutta-percha/AH plus (SMD = − 0.69, 95% CI = − 1.34 to − 0.04, p = 0.04) or the Resilon system (SMD = − 0.54, 95% CI = − 1.07 to − 0.00, p = 0.05). The differences in fracture resistance between the roots filled with Gutta-percha/AH plus and the prepared unfilled root canals was not significant (SMD = 0.59, 95% CI = − 0.02 to 1.21, p = 0.06). Roots obturated with Resilon had higher fracture resistance than instrumented unfilled roots (SMD = 0.83, 95% CI = 0.44 to 1.22, p < 0.0001) or roots filled with Gutta-percha/AH plus (SMD = 0.62, 95% CI = 0.01 to 1.23, p = 0.05).

Conclusions

The present study suggests that filling with Gutta-percha/AH plus dose not reinforce endodontically treated roots, whereas obturating with the Resilon system can increase vertical root fracture resistance of prepared roots. As this meta-analysis was based on in vitro studies, it should be careful to extrapolate its conclusion to the clinical context.

[Study on the incidence of lateral canals and sealing quality in the apical third roots of permanent teeth with failed endodontic treatments]

Objective: To investigate the association between the frequency and filling rate of lateral canals and the sealing quality in the apical third roots of the permanent teeth with failed endodontic treatments, so as to explore the failure factors of root canal therapy. Methods: Clinical records of the permanent teeth with failed endodontic treatments were collected from the Department of Endodontics, Capital Medical University School of Stomatology during a period of 2 years. The teeth were diagnosed as chronic apical periodontitis and then undergone endodontic microsurgery. The sealing quality of the apical root canal was observed by means of periapical radiographs. The surgical treatments were performed and the resected root apices were collected. The samples were scanned by micro-computed tomography and the 3D volume rendered images of the resected root apices were reconstructed. Moreover, the frequency and the filling rate of lateral canals in the apical third roots were calculated. The potential relationship between tooth position and the presence of lateral canals was evaluated. Results: Totally 89 teeth with 89 root apices met the inclusion criteria and were included in the present study. The rate of correct-filling, underfilling and overfilling was 40% (36/89), 32% (28/89), and 28% (25/89), respectively, examined by periapical radiographs. Amongst all of the 89 samples, lateral canals were found in 44 samples. The incidence of apices with lateral canals was 49% (44/89). Furthermore, 3 out of 44 samples were fully filled with material in the lateral canals, and the rest 41 samples showed no filling materials. The filling rate of the lateral canals was 7% (3/44). However, no significant difference was detected between the tooth position and the presence of lateral canals (P>0.05). Conclusions: The sealing quality of the apical third roots in permanent teeth with failed endodontic treatments was not good enough. The incidence of apices with lateral canals was high, but the filling rate of the canals was low. Further studies are needed to explore the relationship between lateral canals and the failure of endodontic treatment.

Prevalence of technical errors and periapical lesions in a sample of endodontically treated teeth: a CBCT analysis

OBJECTIVES

The aims of this study are to identify the most frequent technical errors in endodontically treated teeth and to determine which root canals were most often associated with those errors, as well as to relate endodontic technical errors and the presence of coronal restorations with periapical status by means of cone-beam computed tomography images.

METHODS

Six hundred eighteen endodontically treated teeth (1146 root canals) were evaluated for the quality of their endodontic treatment and for the presence of coronal restorations and periapical lesions. Each root canal was classified according to dental groups, and the endodontic technical errors were recorded. Chi-square's test and descriptive analyses were performed.

RESULTS

Six hundred eighty root canals (59.3%) had periapical lesions. Maxillary molars and anterior teeth showed higher prevalence of periapical lesions (p < 0.05). Endodontic treatment quality and coronal restoration were associated with periapical status (p < 0.05). Underfilling was the most frequent technical error in all root canals, except for the second mesiobuccal root canal of maxillary molars and the distobuccal root canal of mandibular molars, which were non-filled in 78.4 and 30% of the cases, respectively.

CONCLUSIONS

There is a high prevalence of apical radiolucencies, which increased in the presence of poor coronal restorations, endodontic technical errors, and when both conditions were concomitant. Underfilling was the most frequent technical error, followed by non-homogeneous and non-filled canals.

CLINICAL RELEVANCE

Evaluation of endodontic treatment quality that considers every single root canal aims on warning dental practitioners of the prevalence of technical errors that could be avoided with careful treatment planning and execution.

Interaction of backfilling techniques and MTA plugs with additives: Fracture strength and adaptation analyses

The aims were to evaluate the effects of different additives on the adaptation of mineral trioxide aggregate (MTA) plugs before and after different backfilling techniques and analyze the interference of filling procedures on the fracture resistance of simulated immature teeth. The apical parts of 60 teeth were filled with MTA mixed with distilled water (DW), propylene glycol (PG) or calcium chloride (CaCl₂) and backfilled with cold lateral condensation (CLC) or warm vertical compaction (WVC). The specimens were subjected to adaptation analysis and fracture testing. CaCl₂ addition resulted in poor marginal adaptation, while PG addition significantly decreased the fracture values (p<0.05). WVC technique negatively affected the marginal adaptation of MTA-CaCl₂ plugs and decreased the fracture values of teeth with MTA-PG plugs (p<0.05). Mixing MTA with DW can be recommended as apical plug when the remaining root canal space is going to be filled with either CLC or WVC techniques.

Quantification of the tug-back by measuring the pulling force and micro computed tomographic evaluation

Objectives

The aims of this study were to quantify tug-back by measuring the pulling force and investigate the correlation of clinical tug-back pulling force with in vitro gutta-percha (GP) cone adaptation score using micro-computed tomography (µCT).

Materials and Methods

Twenty-eight roots from human single-rooted teeth were divided into 2 groups. In the ProTaper Next (PTN) group, root canals were prepared with PTN, and in the ProFile (PF) group, root canals were prepared using PF (n = 14). The degree of tug-back was scored after selecting taper-matched GP cones. A novel method using a spring balance was designed to quantify the tug-back by measuring the pulling force. The correlation between tug-back scores, pulling force, and percentage of the gutta-percha occupied area (pGPOA) within apical 3 mm was investigated using µCT. The data were analyzed using Pearson's correlation analysis, one-way analysis of variance (ANOVA) and Tukey's test.

Results

Specimens with a strong tug-back had a mean pulling force of 1.24 N (range, 0.15–1.70 N). This study showed a positive correlation between tug-back score, pulling force, and pGPOA. However, there was no significant difference in these factors between the PTN and PF groups. Regardless of the groups, pGPOA and pulling force were significantly higher in the specimens with a higher tug-back score (p < 0.05).

Conclusions

The degree of subjective tug-back was a definitive determinant for master cone adaptation in the root canal. The use of the tug-back scoring system and pulling force allows the interpretation of subjective tug-back in a more objective and quantitative manner.

Stereomicroscopic Dye Leakage Measurement of Six Different Root Canal Sealers

INTRODUCTION

Hermetic sealing of the root canal is the most desirable outcome of any root canal treatment, but almost always the filling of the root canal is defective, which is a multifactorial outcome. One such factor majorly influencing the obturation is the root canal sealer used.

AIM

The present study was done for evaluating microleakage in different root canal sealers.

MATERIALS AND METHODS

Sixty extracted human single rooted teeeth were used in this in-vitro study. Sealers tested for microleakage in this study were zinc oxide eugenol based sealer, Sealapex, AH Plus, MTA Plus, EndoRez, Endosequence BC. All the specimens were examined under stereomicroscope for microleakage and the obtained data were statistically analysed using One-way ANOVA test and Tukey's multiple comparision tests using the software GraphPad Prism 7.02.

RESULTS

The Endosequence BC group showed the least dye leakage and the highest leakage was seen in Zinc oxide Eugenol based sealer.

CONCLUSION

Bio ceramic salers being hydrophilic show better sealing ability compared to resin based and eugenol based sealers.

An Invitro Evaluation of Antimicrobial Efficacy and Flow Characteristics for AH Plus, MTA Fillapex, CRCS and Gutta Flow 2 Root Canal Sealer

INTRODUCTION

Cleaning and shaping of root canal does not guarantee complete disinfection of the canal, regardless of the systems and techniques used for this purpose. Therefore, it becomes mandatory for the endodontic filling materials to have a good antimicrobial potential especially against E. faecalis. This research was aimed therefore to evaluate the antibacterial efficacy and flow properties of different root canal sealers.

AIM

To study invitro antimicrobial activity and flow characteristics for Resin based (AH Plus), Mineral Trioxide Aggregate based (MTA Fillapex), Calcium hydroxide based (CRCS) and Flowable Gutta-Percha (Gutta Flow 2) endodontic sealers on Enterococcus faecalis.

MATERIALS AND METHODS

Enterococcus faecalis ATCC 29212 was used to test antibacterial potential of sealers by Agar diffusion test (ADT) and Direct Contact Test (DCT). ADT was performed by punching the sealers on a well of 4×6mm diameter on Muller Hinton agar plates. These plates were inoculated with standard suspension of E. faecalis and the zone of inhibition was measured at 24 hours and after 7 days. All the sealers were prepared in accordance with the manufacturer's recommendations. Flow of sealers was measured according to ADA specification no. 57.

RESULTS

All sealers showed antibacterial activity against E. faecalis except Gutta Flow 2. At 24 hours, zone of inhibition was highest in Calcibiotic Root Canal Sealer (CRCS) and lowest in AH Plus. After 7 days the zone of inhibition decreased in AH plus, CRCS and MTA Fillapex. DCT showed a significant lower number of organisms in AH Plus, CRCS and MTA than controls at both the time intervals. Gutta Flow 2 did not show any significant antimicrobial action. Maximum and minimum flow was shown by AH Plus and CRCS respectively.

CONCLUSION

Highest microbial inhibition was shown by (CRCS), followed by MTA Fillapex and AH Plus. Gutta Flow 2 did not show any inhibition of E. faecalis by ADT. Maximum reduction in antibacterial property with time against E. faecalis was seen with AH Plus. Maximum flow was shown by AH Plus and minimum by CRCS.

Calcium Hydroxide Dressing Influences the Obturation of Simulated Lateral Canals

AIM

The aim of this study was to investigate the influence of calcium hydroxide dressing on the filling of simulated lateral canals by different obturation techniques.

MATERIALS AND METHODS

Sixty single-root-premolars were instrumented. Simulated lateral canals were drilled on each third of the roots. The teeth were divided into four groups: no dressing and obturation by lateral condensation technique (G1), dressing with calcium hydroxide and obturation by lateral condensation technique (G2), no dressing and obturation by hybrid technique (G3) and, dressing with calcium hydroxide and obturation by hybrid technique (G4). The teeth were maintained at 37°C in 100% humidity for 7 days, and obturation techniques were performed. Radiographs were taken and filled or unfilled lateral canals were counted. Data were analyzed using analysis of variance (ANOVA) followed by Tukey's test (a = 5%).

RESULTS

The hybrid technique filled large number of lateral canals as compared to lateral condensation technique, regardless the use of intracanal medication (p < 0.05). Calcium hydroxide decreased the number of lateral canals filled for both lateral and hybrid techniques (p < 0.05). Significant differences were observed when comparing the number of filled and unfilled lateral canals in the same root third of each group (p < 0.05).

CONCLUSION

Regardless the obturation technique, calcium hydroxide dressing reduced the penetration of filling material in simulated lateral canals.

CLINICAL SIGNIFICANCE

The persistence of calcium hydroxide residues reduces the penetration of filling material in simulated lateral canals, possibly representing a potential cause of failure in the future.

Comparison of Obturation Quality in Modified Continuous Wave Compaction, Continuous Wave Compaction, Lateral Compaction and Warm Vertical Compaction Techniques

OBJECTIVES

The aim of this study was to introduce modified continuous wave compaction (MCWC) technique and compare its obturation quality with that of lateral compaction (LC), warm vertical compaction (WVC) and continuous wave compaction techniques (CWC). The obturation time was also compared among the four techniques.

MATERIALS AND METHODS

Sixty-four single-rooted teeth with 0-5° root canal curve and 64 artificially created root canals with 15° curves in acrylic blocks were evaluated. The teeth and acrylic specimens were each divided into four subgroups of 16 for testing the obturation quality of four techniques namely LC, WVC, CWC and MCWC. Canals were prepared using the Mtwo rotary system and filled with respect to their group allocation. Obturation time was recorded. On digital radiographs, the ratio of area of voids to the total area of filled canals was calculated using the Image J software. Adaptation of the filling materials to the canal walls was assessed at three cross-sections under a stereomicroscope (X30). Data were statistically analyzed using ANOVA, Tukey's post hoc HSD test, the Kruskal Wallis test and t-test.

RESULTS

No significant difference existed in adaptation of filling materials to canal walls among the four subgroups in teeth samples (P ≥ 0.139); but, in artificially created canals in acrylic blocks, the frequency of areas not adapted to the canal walls was significantly higher in LC technique compared to MCWC (P ≤ 0.02). The void areas were significantly more in the LC technique than in other techniques in teeth (P < 0.001). The longest obturation time belonged to WVC technique followed by LC, CW and MCWC techniques (P<0.05). The difference between the artificially created canals in blocks and teeth regarding the obturation time was not significant (P = 0.41).

CONCLUSION

Within the limitations of this in vitro study, MCWC technique resulted in better adaptation of gutta-percha to canal walls than LC at all cross-sections with fewer voids and faster obturation time compared to other techniques.

Factors associated with postoperative pain in endodontic therapy

OBJECTIVE

To assess postoperative pain in endodontic therapy and its association with clinical factors such as gender, age, tooth type, pulpal diagnosis, and preoperative pain, length of obturation and sealer extrusion.

STUDY DESIGN

Cross-Sectional study.

PLACE AND DURATION OF STUDY

Dental section of the Aga khan university hospital, Karachi, Pakistan from January to December 2009.

METHODOLOGY

One hundred and forty patients (140) requiring endodontic therapy for molar and premolar teeth were included in this study. Local Anesthesia (2% Lidocain with 1:80,000 Epinephrine) was administered. The tooth was isolated with rubber dam. Access cavity was prepared with the help of round carbide No. 2 bur. Canal preparation was completed using crown-down technique. Access was sealed with sterile dry cotton pallet and restored temporarily with double layer of Glass ionomer cement and Cavit. After one week patients were recalled and access was re-opened, obturation was done using cold lateral condensation technique. Ca(OH)(2) based sealer was used. Postoperative radiographs were taken. Patients were recalled after 24 hours and postobturation pain was recorded using Visual analogue scale (VAS).Data was obtained on a structured Performa. χ(2) test was used for statistical analysis.

RESULTS

Pain was present in 42.9% of patients. Females more frequently experienced pain (65%) than males (35%). Preoperative pain was found to be significantly associated with postoperative pain (p value < 0.001). Obturation length was not found to be significantly associated with postoperative pain (p value 1.0). Sealer extrusion was not found to be significantly associated with postoperative (P value 0.547).

Filling lateral canals: evaluation of different filling techniques

OBJECTIVES

The purpose of this in vitro quantitative laboratorial study is to compare the ability of three filling techniques to fill simulated lateral canals.

METHODS

Thirty extracted, single-rooted human teeth were used. After cleaning and shaping, three lateral canals were created, one in each third. The teeth were randomly separated into three groups: continuous wave of condensation (Group 1); thermomechanical compaction (Group 2); and lateral condensation (Group 3). The teeth were cross-sectioned, making the cut through points over the lateral canals; thus, 90 specimens were obtained. Each specimen was immersed in a polyester resin, and the blocks were polished. Images were obtained using a stereoscopic lens (40x). Radiographic analysis was performed, followed by a filling linear measure using the Image Tool 3.0 program (University of Texas). Data were statistically analyzed using SPSS 12.0 for Windows (Kruskal-Wallis test).

RESULTS

A greater number of simulated lateral canals were obturated in Groups 1 and 2. Group 2 presented the largest percentage of linear measure of lateral canals filling with gutta-percha and sealer. No statistical differences were found between Group 1 and Group 2 when we analyzed the filling with gutta-percha and sealer or just sealer (P>.05).

CONCLUSIONS

Thermoplasticized gutta-percha filling techniques (Groups 1 and 2) are better for filling lateral canal with gutta-percha and sealer or with just sealer than lateral condensation (Group 3).

In vitro comparison of apical leakage in root canals obturated with 0.04 and 0.02 tapered gutta-percha

INTRODUCTION

Gutta-percha is the most commonly used material for root canal obturation; it has been recently manufactured with different tapers. The aim of this in vitro study was to compare microleakage of canals obturated with standard gutta-percha (0.02 taper) or the new 0.04 taper gutta-percha master cone using the cold lateral condensation technique.

MATERIALS AND METHODS

Forty-four extracted single rooted teeth were selected. The crowns were removed and all the canals were prepared using RaCe rotary files. The teeth were then divided into experimental (n=2) and control (n=2) groups. In the first study group, the teeth were obturated with 0.02 taper gutta-percha master cone and lateral condensation. In the second study group, the canals were obturated by 0.04 tapered master cones and the same obturation method. The degree of leakage was measured using fluid filtration method. Data were analyzed statistically by student t-test.

RESULTS

There was no significant difference between the mean microleakage of two experimental groups (P=0.558).

CONCLUSION

Lateral condensation technique using 0.04 tapered master cones can provide an effective apical seal similar to 0.02 gutta-percha cones.

A comparative study of density of obturated root canals by conventional and mechanical lateral condensation techniques

BACKGROUND

The purpose of this study was to compare the weight of root canal filling material used in a new lateral condensation technique named mechanical lateral condensation (MLC) with that of conventional lateral condensation technique (LC). This new technique uses reciprocal handpiece.

METHODS

In this experimental study, 40 human extracted straight canine teeth were used. After crown amputation, root canals were prepared with 18 mm in length. The teeth were randomly divided into four experimental groups; each group was consisting of 10 teeth. The teeth in groups IA and IB were filled by LC technique. The teeth in groups IIA and IIB were filled by MLC technique and using a finger spreader that placed in a reciprocating-action handpiece to laterally condense cold gutta-percha, creating space for accessory cones. All of the roots were weighted before and after obturation and the difference demonstrated the weight of gutta-percha mass. The data were analyzed by t-test.

RESULTS

The mean weight for MLC obturations was 10.82 ± 0.025 g compared with 7.37 ± 0.035 g for that of LC technique. The difference was statistically significant (P = 0.001).

CONCLUSION

This study showed that MLC technique requires more gutta-percha mass than LC technique.