Recent literature has suggested a potential association between inflammatory bowel diseases (IBD) and apical periodontitis (AP). The present systematic review and meta-analysis sought to analyse and appraise the available evidence regarding the reported association. Following 2020 PRISMA guidelines, a comprehensive search of multiple online databases (PubMed, Scopus, Web of Science, and Google Scholar) was conducted for all relevant studies published from the date of inception until 27 April 2023 using various relevant keywords. All observational studies that assessed the association between IBD and AP in humans were eligible for inclusion. The quality of the selected studies was carried out independently by two reviewers, and meta-analysis was performed using Comprehensive Meta-Analysis Version 2.2.064. Six studies (five case-control studies and one cohort study) were included. A total of 657 patients (277 with IBD) were included in 5 case-control studies, and 48,223 subjects (35,740 with AP) were included in the cohort study, where 188 developed IBD on follow-up. The pooled data from the five case-control studies revealed that IBD was significantly associated with a higher risk of AP (OR=1.71, 95% CI: 1.21–2.42; I2=10.337%, fixed-effect, p=0.002). The qualitative analysis also showed that most of the included studies found a higher mean number of teeth with AP in IBD groups than the healthy controls. Newcastle-Ottawa Scale (NOS)-based quality appraisal results demonstrated that five studies were of high quality, and one was of moderate quality. The results suggest a potential association between IBD and AP. Large-scale and prospective studies are required to further confirm and elucidate the nature of such an association. (EEJ-2023-05-057)

With the ever-increasing understanding of tooth anatomy, there is a renewed focus on the pulp chamber as an important component of the root canal system. For example, the pulp chamber is of critical relevance during diagnostic procedures such as pulp sensibility tests, deep caries removal, vital pulp treatments, access cavity preparation, tooth whitening, tooth restoration as well as methods for examining the floor of the pulp chamber to aid the detection of root canal orifices or the presence of perforations and cracks. The more recent concept of minimal invasive endodontics has also created a need to understand better the anatomy of the pulp chamber. The purpose of this article is to discuss the research methods used to study pulp chamber anatomy and the significance of the pulp chamber in endodontic research and clinical practice. In addition, directions for future research are emphasised. (EEJ-2023-08-105)

Objective: To evaluate the effect of diode laser (GaAlAs-980 nm) for full coronal pulpotomy (FCP) compared to conventional crown pulpotomy (CCP) in mature teeth with symptomatic irreversible pulpitis (SIP) and assess dentine bridge formation after FCP using CBCT.
Methods: A total of 86 patients (43 per group) with SIP in permanent mandibular molars were included. Access opening and FCP were done, after which haemostasis was achieved with 2.5% NaOCl in the CCP group and a diode laser (GaAlAs-980 nm) in the laser crown pulpotomy group (LCP). Biodentine (Septodont, Saint-Maur-des-Fossés, France) was placed, and the cavity was sealed. Clinical and radiographic follow-ups were done at 6, 12, and 18 months, with additional CBCT evaluation at 18 months. Statistical analysis was performed using the Mann-Whitney U test, and survival rates were assessed using Kaplan-Meier analysis. The Cox proportional model was used to determine the effect of possible covariates on pulpotomy outcomes. P<0.05 was considered to be statistically significant.
Results: The overall success rate for CCP and LCP at 18 months was 88.4% and 93% respectively. At the end of 18 months, 8 cases (5 in CCP, 3 in LCP) failed. The postoperative pain score at 48 hours was significantly higher for CCP (mean ± standard deviation: 1.7±1.4; p<0.001). CBCT analysis at 18 months revealed thicker dentine bridge formation for LCP (Median & IQR: 0.89, 1.06) compared to CCP (p=0.0479). The Kaplan-Meier curve showed a more rapid decline in the survival rate of CCP (0.89) compared to that of LCP (0.93). Postoperative pain at 48 hours, PAI scores at 6, 12, 18 months, and age were found to affect the hazard ratio based on the Cox regression model.
Conclusion: Within the limitations of this trial, there was no significant difference in the outcome between diode laser and conventional pulpotomy. However, LCP resulted in lesser postoperative pain at 48 hours and thicker dentine bridge formation at 18 months, with a longer estimated survival rate. (EEJ-2023-01-011)

Objective: To compare the survival rate against fracture of endodontically treated anterior teeth (ETT) affected by cervical (class V) lesions with pulpal involvement restored with resin composite or a post/core and crown, and to identify the prognostic factors for fracture.
Methods: Dental records and radiographs of ETT affected by cervical lesions with pulpal involvement restored with resin composite or a post/core and crown during a recall period from 2009–2022 were selected according to the inclusion and exclusion criteria. The number of tooth fracture, the restorability after fracture and any possible risk factors were identified. The survival rate against ETT fracture were analyzed and com- pared between the two restoration groups by Kaplan-Meier survival analysis and the Tarone-Ware test. Non- proportional hazard models were used to identify the prognostic factors. The sub-analysis in each restoration group was also performed.
Results: The study comprised 175 ETT restored with resin composite (n=125) or a crown (n=50). With a mean recall period of 32.9±15.8 months, the survival rate against ETT fracture with resin composite (85.6%) was not significantly different from those with a crown (88%) (p≥0.05). The most frequent mode of fracture was crown-root fracture, which accounted for 78% and 83.30% of the fractures in the resin composite and crown groups, respectively. A significant prognostic factor for ETT fracture affected by cervical lesions with pulpal involve- ment was additional tooth structure loss from a class III, class IV or another class V lesion on the opposite side (p<0.05). The ETT affected by cervical lesions with pulpal involvement combined with additional tooth structure loss had a 7.25-fold higher risk of fracture than those with single-surface affected by cervical lesions with pulpal involvement (hazard ratio [HR] = 7.25; 95% confidence interval [CI], 1.68–31.30). The sub-analysis in the crown and resin composite groups revealed that the survival rates of ETT with single-surface affected by cervical lesions with pulpal involvement was 100% and 96.15%, respectively, which were significantly higher than those of ETT with additional tooth loss at 80.65% and 78.08%, respectively (p<0.05).
Conclusion: With a mean 33-month recall period, the survival rate against ETT fracture affected by cervical lesions with pulpal involvement restored with resin composite or crown were not significantly different. Additional tooth structure loss was a significant prognostic factor for fracture. (EEJ-2022-12-161)

Objective: The aim was to compare the “reverse sandwich restoration” to resin composite restorations re- garding marginal adaptation, fracture resistance, favourable/unfavourable fractures in the management of external cervical resorption.
Methods: Forty-eight extracted maxillary central incisors were selected and endodontically treated. Cervical regions of the labial root surfaces received simulated resorptive defects and were restored as three randomly allocated groups: Reverse Sandwich Restoration (resin composite + resin-modified glass ionomer) (RSR); resin composite restoration (COMP), and no restoration (NR). Each group was further divided into two subgroups (n=8 each): Thermomechanical Aging (TA) (equivalent to one year) and No Aging (NA). Marginal adaptation was scored by scanning electron microscopy. Fracture resistance was tested using a universal testing machine. Favourable versus unfavourable fractures were classified based on fracture extent.
Results: TA decreased the marginal adaptation for both RSR and COMP. Mean fracture resistance per groups were: RSR-NA 1522.4±94.9N, RSR-TA 939.6±72.9N, COMP-NA 1197.6±95.7N, COMP-TA 870.4±86.3N, NR-NA 1057.1±88.1N, and NR-TA 836.6±81.9N, respectively. Fracture resistance was the highest for RSR- NA compared to all other groups (p<0.05). TA decreased the fracture resistance in all groups (p<0.05), there was no significant difference between RSR and COMP regarding fracture resistance and favourable/ unfavourable fractures (p>0.05).
Conclusion: RSR provided comparable results to resin composite fillings to restore artificial cervical defects pertaining to marginal adaptation, fracture resistance, and favourable versus unfavourable fractures. RSR is preferable due to its inherent biocompatibility to the periodontium. (EEJ-2023-04-050)

Objective: This study aimed to examine the mandible form features of the mandible, such as inter-second molar width, anteroposterior length, arch perimeter length, arch breadth, corpus height/width in the mandibular second molars (MnSM) region, and arch form, and the relation for the occasion of the 1-rooted/C-shaped.
Methods: The study analyzed cone-beam computed tomography images of 215 male and 215 female Turkish patients to determine the prevalence of 1-rooted and C-shaped MnSM. Mandibular dentoalveolar characteristics of individuals with bilateral (1R-1R group) and unilateral (1R-2R group) 1-rooted MnSM were examined and compared with those with bilateral 2-roots (2R-2R group) MnSM. Statistical tests were performed using Chi-square, one-way ANOVA, Tukey, and binary logistic regression analysis at the 5% significance level.
Results: The prevalence of 1-rooted and 1-rooted/C-shaped MnSM was 12.79% and 9.65%, respectively. Root fusion was more commonly present in females (p<0.05). In the 1R-1R group, the anteroposterior length was shorter than in the 2R-2R group (p<0.05). There was no difference between the groups for other features (p>0.05).
Conclusion: Although the study found a shorter anteroposterior length in the 1R-1R group, no feature was a predictive variable for 1-rooted/C-shaped MnSM. (EEJ-2023-05-058)

Objective: Irrigating solutions play an important role in the debridement and disinfection of the root canal space, and thus, it is crucial to comprehend their effects on the composition and surface structure of radicular dentine. This study evaluated and compared the effects of 17% ethylenediaminetetraacetic acid (EDTA), 9% 1-hydroxyethylidene-1,1-bisphosphonate (HEBP) and 0.2% chitosan on the mineral content and erosion of radicular dentine when used as a final rinse.
Methods: Sixty extracted human mandibular premolar teeth were decoronated and instrumented to ProTaper size F2. After final instrumentation, the samples were randomly divided into 4 groups (n=15) according to the type of final irrigant used: Normal saline (control), 17% EDTA, 9% HEBP and 0.2% chitosan. Field emission scanning electron microscopy was used to assess the erosion of radicular dentine, and energy dispersive X- ray spectroscopy was used to quantify the radicular dentine mineral composition at the coronal, middle and apical levels of all the prepared samples after final irrigation. The one-way analysis of variance was used for intra-group and inter-group comparisons of means, the Kruskal Wallis test for intra-group and inter-group comparisons of medians and Tukey’s post hoc test for pairwise comparisons.
Results: There was no significant difference in the levels of calcium (Ca), phosphorus (P) and Ca/P ratio after final rinse with 17% EDTA, 9% HEBP and 0.2% chitosan at all three root levels (p>0.05); except at the coronal level, where 0.2% chitosan caused significantly less alteration in Ca levels and Ca/P ratio than 17% EDTA and 9% HEBP respectively (p<0.05). 17% EDTA, 9% HEBP and 0.2% chitosan caused no erosion at the middle and apical levels. Meanwhile, 17% EDTA and 9% HEBP caused moderate erosion at the coronal level.
Conclusion: Alternatives to 17% EDTA during final irrigation can be 9% HEBP and 0.2% chitosan. (EEJ-2023-06-078)

Objective: The aim of this in vitro study was to compare the smear layer and debris removal and antimicrobial activity of two dual-action irrigating solutions for continuous chelation (Triton; Brasseler, Savannah, USA and Dual Rinse HEDP; Medcem GmbH, Weinfelden, Switzerland) with a dual step irrigation protocol with sodium hypochlorite (NaOCl) followed by ethylenediaminetetraacetic acid (EDTA).
Methods: Thirty single-rooted single-canal teeth were divided into three groups (n=10) and irrigated with Triton, Dual Rinse HEDP mixed with 6% NaOCl and 6% NaOCl/17% EDTA. The teeth were observed under a scanning electron microscope (SEM) to assess the canal wall cleanliness. In addition, 80 dentine discs were contaminated with Candida albicans and 80 discs with Enterococcus faecalis and irrigated with Triton, Dual Rinse HEDP mixed with 6% NaOCl and 6% NaOCl/17% EDTA or not treated (n=20). Fifteen discs were used to evaluate colony-forming units, while 5 discs were analysed by SEM. Data were analysed using the Shapiro- Wilk, Kruskal-Wallis and One-Way ANOVA tests.
Results: Triton was statistically more effective than Dual Rinse HEDP and NaOCl/EDTA in removing debris (p<0.05), except with NaOCl/EDTA in the coronal third. Triton was more effective than Dual Rinse HEDP in removing the smear layer from the apical and middle thirds (p<0.05). All the irrigation protocols significantly re- duced the number of E. faecalis. The Triton group showed the lowest number of remaining C. albicans (p<0.05).
Conclusion: Triton was the most effective irrigation solution in removing debris and as effective as NaOCl/ EDTA in removing the smear layer. Triton showed the highest efficacy against C. albicans. New irrigating solutions that provide continuous chelation may provide an alternative to current irrigation protocols. (EEJ-2022-12-168)

Objective: Computational fluid dynamic analysis (CFD) is claimed to be a reliable tool for analysing the fluid flow and the generated apical pressures in the simulated root canal. The current study aimed to analyse the apical pressures in extracted teeth with single and joining canals.
Methods: Forty-six freshly extracted teeth were collected for the present study. The power was set at 95%, with an effect size of 0.55 (1-β=95%, α=0.05). Once the root canal anatomy was confirmed with cone-beam computed tomography (CBCT), they were divided into two groups: group I: mandibular second premolars with Vertucci type-I (n=23), and group II: maxillary second premolars with Vertucci type-II (n=23). The instrumentation of the specimens was carried out to a 0.04-taper using rotary instruments. A post-instrumentation CBCT was obtained, and computer-aided design models were obtained. The CFD simulations were then con- ducted with simulated 30-gauge side vented needles at 25, 50, and 75% short of the working length (WL).
Results: Group I recorded significantly (p<0.05) higher apical pressures at needle positions 25% short of the WL. However, no significant differences were elicited in the groups at other needle positions.
Conclusion: Single canal specimens recorded higher apical pressures at needle positions 25% short of the WL. However, no differences were elicited between single and joining canals at higher needle positions. (EEJ-2022-09-120)