Prevalence of apical periodontitis and its association with previous root canal treatment, root canal filling length and type of coronal restoration - a cross-sectional study

Does selective root canal retreatment preserve the tooth's fracture resistance? An ex-vivo study

OBJECTIVES

To assess the tooth's fracture resistance when submitted to a selective root canal retreatment compared to the conventional approach.

METHODS

33 intact permanent mandibular first molars were selected according to specific criteria. After teeth mounting, the primary root canal treatment was conducted and followed by thermo-mechanical aging procedures to mimic a few clinical conditions. The specimens were randomly divided into three groups (n = 11); a control group in which intact teeth were used and two experimental groups according to the retreatment approach: conventional non-surgical retreatment (Conventional-NSR), and selective non-surgical retreatment (Selective-NSR). Later, the teeth were submitted to a final thermo-mechanical aging procedure and tested regarding their fracture resistance (static fracture test). The maximum load to fracture was recorded as were the types of failure modes (repairable or non-repairable fracture). A proper statistical analysis was conducted, considering a significance level of 5%.

RESULTS

The Conventional-NSR group showed a mean failure load of 867.7 ± 108.9 N while the Selective-NSR group had 1106.8 ± 159.8 N (P = 0.012). Both retreatment groups showed significantly lower results when compared to the control group. Additionally, the Conventional-NSR group showed higher proportions of non-repairable fractures (54.5%) when compared to both the Selective-NSR (36.4%) and control (18.2%) groups.

CONCLUSIONS

Selective root canal retreatment preserved the tooth's fracture resistance compared to the conventional retreatment approach.

CLINICAL TRIAL NUMBER

Non-applicable. Conducting the current experiment was limited to obtaining approval from the local Research Ethics Committee at the Faculty of Dentistry, Minia University (Committee No. 105, Registration No. 902, Date: 26/3/2024).

The prevalence of root canal treatment, periapical status, and coronal restorations in elderly patients in the Polish population

Objectives

The aim of this retrospective cohort study was to determine the prevalence and correlations between root canal treatment, periapical status, and coronal restoration detected using cone beam computed tomography (CBCT) in the elderly Polish population (60-79 years).

Methods

A total of 480 CBCT images were assessed. Collected data included: age, gender, the tooth location, direct restoration, decay, single crown, abutment of fixed bridge, the quality of the restoration, root canal treatment, post and core, apical periodontitis (AP), and quality of root filling.

Results

The number of teeth in the elderly patients decreased, while the number of endodontically treated teeth increased with age. More teeth were preserved in mandible, the most common group of teeth were incisors. AP was more often detected in the maxilla in general, and in mandibular molars. The over-filling was observed more frequently in maxilla, in maxillary molars and in mandibular premolars, while the short-filling in maxillary and mandibular molars. AP was significantly more often observed in short-filled root canals than in other length criteria (overfilled, adequately, lack of filling).

Conclusions

Inadequate prosthetic restoration, presence of post, pulpotomy, missed canals and root canal treated teeth were associated with increased prevalence of AP.

Clinical significance

The article indicates the need of treatment of elderly population in Poland. There is the demand to enhance the quality of endodontic and restorative treatment in this population. Additionally, CBCT examination, if indicated, should be implemented in the course of endodontic therapy to provide adequate information to clinicians.

Assessment of Periodontitis Risk Factors in Endodontically Treated Teeth: A Cross-Sectional Study

The aim of the study was to collect data about the prevalence and risk factors of apical periodontitis in a population of endodontically treated patients. The study group included 151 patients (52 males, 99 females; mean age 48.36 ± 15.708 yrs.) with 391 endodontically treated teeth (mean follow-up of 5.25 ± 1.759 yrs.). According to the initial tooth diagnosis, root-filled teeth were divided into Group A, root-filled teeth treated for pulpitis or for the purpose of prosthetic pulpectomies (vital pulp group), and Group B, root-filled teeth with non-vital pulp (necrotic pulp). Clinical and radiographic evaluation of the root and its periapical area were performed to establish the success/failure of endodontic therapy, the quality of the root canal fillings (length, density, taper), and coronal restoration. The presence of recurrent caries, periodontal pathology, or endo-periodontal lesions were also recorded. Univariate and multivariate analyses were used to determine the risk factors for apical periodontitis and calculate their odds ratios (ORs). For the root-filled vital pulp tooth group, the highest risks for apical periodontitis are associated with inadequate homogeneity (OR 30.938), periodontitis (OR 9.226), and over-filling (OR 8.800). For the root-filled non-vital pulp tooth group, the highest risks are associated with periodontitis (OR 4.235) and age over 60 yrs. (OR 4.875). For the necrotic pulp tooth group, multivariate analysis identified an age > 60 yrs., filled molars, intracanal posts, poor coronal restoration quality, under-filling, and periodontitis as significant combined risk factors. Inadequate root canal filling and periodontitis in both groups were risk factors associated with most cases of apical periodontitis. Other risk factors include age > 60 yrs., poor coronal restoration quality, and the presence of intracanal posts in root-filled teeth with necrotic pulp.

Assessment of endodontic treatment and prevalence of apical periodontitis using cone-beam computed tomography: a cross-sectional study

Purpose

The purpose of this study was a retrospective cross-sectional study of the Polish subpopulation, performed to evaluate the quality of endodontic treatment (ET) and the condition of the periapical tissues of permanent teeth based on cone-beam computed tomography (CBCT) images.

Material and methods

The retrospective study included a group of patients who underwent CBCT at the University Dental Clinic of the Pomeranian Medical University in Szczecin. An endodontically treated tooth index (ETTI) was used to evaluate ET. Once apical periodontitis was recognised, the size, extent, and ratio of adjacent anatomical structures were assessed using the complex periapical index (COPI).

Results

Analysis of the CBCT images showed that ET was performed in 9.9% of the teeth examined, of which 52.7% of the canals were treated correctly, while 28.1% of the root canals were found to be underfilled, 6.8% were overfilled, 9.3% of the root canals were not obturated at all, and in 3.1% of the teeth examined, the filling material was only visible in the pulp chamber. Apical periodontitis was observed in 6% of all teeth examined, while the percentage of teeth following ET was 38.5%.

Conclusions

The quality of the ET provided to the Polish subpopulation is unsatisfactory. Lack of root canal filling homogeneity is a significant risk factor for ET failure. Improper ET and poor quality of crown restoration after ET have an impact on the increased risk of occurrence, size, degree of root coverage, and extent of inflammatory periapical lesions in relation to adjacent anatomical structures.

Is SWEEPS better than PUI in reducing intracanal bacteria and inflammation in cases of apical periodontitis?

To evaluate the efficacy of SWEEPS mode of the Er: YAG laser(SL) and passive ultrasonic irrigation(PUI) in the eradication of microorganisms and in the inflammation detection by IL-1β. Thirty patients with chronic apical periodontitis(AP) were allocated into two groups: Group SL-SWEEPS laser activated irrigation(n = 15) and Group PUI-passive ultrasonic irrigation(n = 15). Bacteriological samples were taken before(S1) and after chemomechanical preparation(S2), and then after final irrigation activation(S3). The levels of total bacteria and Streptococci were measured by means of PCR. Blood samples were collected before and 3rd day after treatment. Enzyme-linked immunosorbent assay was used to measure the levels of IL-1β. The bacterial reduction showed no differences between groups after chemo-mechanical treatment and after irrigant activation(p = 0.590). Post-treatment IL-1β levels were lower than pretreatment levels in both groups(p < 0.001). SL or PUI application in addition to chemomechanical preparation has similar effects on total bacterial level and inflammation detected by IL-1β in patients with AP.

Relationship of MMP-9 with the clinical course of apical periodontitis and the main bacterial species in the oral microbiota

Bacterial products, host immune cells and cytokines have been reported to play an important role in the pathogenesis of apical periodontitis (AP). This study aimed to determine the main bacterial species in the microbiota as gram positive and negative and to compare the relationship between matrix metalloproteinase (MMP)-9 and tumor necrosis factor (TNF)-α with controlled patient groups. 60 patients with AP and extraction indication were included in the study. 30 systemically healthy volunteers without AP were selected as the control group. After access cavity preparation, an initial microbiologic sample (S1) was taken from the root canal. After atraumatic extraction of the tooth, a second microbial sample (S2) was taken from the extraradicular region. After bacterial DNA extraction, 16S rRNA gene primer was designed for sequence analysis. Bacterial community profiling was made by Sanger sequencing of the PCR products. In addition, serum MMP-9 and TNF-α levels were measured from all patients. TNF-α levels of the AP group were higher than the control group, while MMP-9 levels were found to be lower (p = 0.0264 and p = 0.0146, respectively). There was no difference in the main bacterial species isolated from the samples taken from the intracanal and extraradicular region of the tooth with AP (p = 0.714). The main bacterial species in the intracanal region of the tooth with AP are similar to the main bacterial species in the extraradicular region. The pathophysiology of the tooth with AP is associated with low MMP-9 and high TNF-α, independent of the bacterial species in the intracanal and extraradicular regions.

Effect of apical foraminal enlargement on postoperative pain and inflammatory markers in asymtomatic single-rooted mandibular teeth with apical periodontitis - An in vivo randomized controlled trial

Aim of the Study

This study aims to assess the effect of apical foraminal enlargement on inflammatory markers and pain in patients with asymptomatic single-rooted mandibular teeth with apical periodontitis.

Materials and Methods

The study included 60 patients based on inclusion and exclusion criteria. Before beginning root canal treatment (RCT), a blood sample was obtained from the antecubital fossa to evaluate the inflammatory markers, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR). Access opening was done and initial irrigation was done. Working length (WL) was determined with an electronic apex locator and verified with a radiograph. In the control group, the determined WL was maintained, while in the experimental group, the WL was set till the apical foramen. Biomechanical preparation was done in both groups till F2 or F3 based on the initial apical file, followed by final irrigation and obturation based on the master apical file size. Patients were given a Visual Analog Scale to record pain sensations at 24, 48, and 72 h postoperative. After 72 h, patients were recalled for follow-up appointments, and blood was taken from the antecubital fossa again to evaluate inflammatory markers.

Statistical Analysis

The resultant findings for the reduction in inflammatory markers before and after RCT with or without foraminal enlargement were statistically analyzed using the Student's t-test. The pain was statistically examined with one-way "analysis of variance" and Tukey's post hoc test for inter-group comparison of pain. The level of significance was set at P < 0.05. The statistical analysis was performed using Statistical Package for the Social Sciences (SPSS) Version 23 for Windows (SPSS Inc., Chicago, IL, USA). As pain in the control groups is zero before and after RCT, statistical analysis is not required as the overall pain score is zero.

Results

The P values of the CRP and ESR of the control group were 0.02 and 0.03, respectively, which indicates it is significant whereas the P values of the ESR and CRP of the experimental group were 0.0002 and 0.0008 which indicates it is highly significant. Results indicate that the experimental group is more effective compared to the control group in reducing inflammatory markers. Pain in the control group after RCT was zero at the end of 24, 48, and 72 h. In the experimental group, where RCT was done with apical foraminal enlargement, mild pain was present at the end of 24 h which gradually decreased at the end of 48 h and no pain was reported at the end of 72 h.

Conclusion

Reduction in inflammatory markers was more effective in RCT with apical enlargement than without apical enlargement. RCT with apical enlargement caused mild pain in the patients immediately after treatment which gradually decreased over time.

The importance of mechanosensitive cell mediated prostaglandin and nitric oxide synthesis in the pathogenesis of apical periodontitis: comparative with chronic periodontitis

OBJECTIVES

Mechano-sensitive odontoblast cells, which sense mechanical loading and various stresses in the tooth structure, synthesize early signaling molecules such as prostaglandin E2 (PGE2) and nitric oxide (NO) as an adaptive response. It is thought that these synthesized molecules can be used for the diagnosis and treatment of periodontal and periapical diseases. The aim of this study was to investigate the relationship between the severity of apical periodontitis (AP) and chronic periodontitis (CP) and serum (s) TNF-α, IL-10, PGE2 and NO levels, as well as PGE2 and NO levels in gingival crevicular fluid (GCF) samples.

MATERIALS & METHODS

A total of 185 subjects were divided into three categories: AP group (n = 85), CP group (n = 50) and healthy control group (n = 50). The AP group was divided into 3 subgroups according to abscess scoring (AS-PAI 1, 2 and 3) based on the periapical index. The CP group was divided into 4 subgroups according to the periodontitis staging system (PSS1, 2,3 and 4). After recording the demographic and clinical characteristics of all participants, serum (s) and gingival crevicular fluid (GCF) samples were taken. TNF-α, IL-10, PGE2 and NO levels were measured in these samples.

RESULTS

Unlike serum measurements (sTNF-α, sIL-10, sNO and sPGE2), GCF-NO and GCF-PGE levels of the AP group were significantly higher than the control group in relation to abscess formation (54.4 ± 56.3 vs. 22.5 ± 12.6 µmol/mL, p < 0.001 and 100 ± 98 vs. 41 ± 28 ng/L, p < 0.001, respectively). Confirming this, the GCF-NO and GCF-PGE levels of the AS-PAI 1 group, in which abscesses have not yet formed, were found to be lower than those in AS-PAI 2 and 3, which are characterized by abscess formation [(16.7(3.7-117.8), 32.9(11.8-212.8) and 36.9(4.3-251.6) µmol/mL, p = 0,0131; 46.0(31.4-120.0), 69.6(40.3-424.2) and 74.4(32.1-471.0) ng/L, p = 0,0020, respectively]. Consistent with the increase in PSS, the levels of sTNF [29.8 (8.2-105.5) vs. 16.7(6.3-37.9) pg/mL, p < 0.001], sIL-10 [542(106-1326) vs. 190(69-411) pg/mL, p < 0.001], sNO [182.1(36.3-437) vs. 57.0(15.9-196) µmol/mL, p < 0.001], sPGE2 [344(82-1298) vs. 100(35-1178) ng/L, p < 0.001], GCF-NO [58.9 ± 33.6 vs. 22.5 ± 12.6 ng/L, p < 0.001] and GCF-PGE2 [ 99(37-365) vs. 30(13-119), p < 0.001] in the CP group were higher than the control group. Comparison ROC analysis revealed that the GCF-PGE2 test had the best diagnostic value for both AP and CP (sensitivity: 94.1 and 88.0; specificity: 64.0 and 78.0, respectively; p < 0.001).

CONCLUSIONS

GCF-PE2 and GCF-NO have high diagnostic value in the determination of AP and CP, and can be selected as targets to guide treatment. In addition, the measurements of PGE2 and NO in GCF can be used as an important predictor of pulpal necrosis leading to abscess in patients with AP.

CLINICAL RELEVANCE

In this article, it is reported that syntheses of early signaling molecules such as PGE2 and NO can be used for the diagnosis and treatment target of periapical and periodontal infections.

Efficacy of electronic apex locators in comparison with intraoral radiographs in working length determination- a systematic review and meta-analysis

BACKGROUND

Successful endodontic treatment needs accurate determination of working length (WL). Electronic apex locators (EALs) were presented as an alternative to radiographic methods; and since then, they have evolved and gained popularity in the determination of WL. However, there is insufficient evidence on the post-operative pain, adequacy, and accuracy of EALs in determining WL.

OBJECTIVE

The systematic review and meta-analysis aims to gather evidence regarding the effectiveness of EALs for WL determination when compared to different imaging techniques along with postoperative pain associated with WL determination, the number of radiographs taken during the procedure, the time taken, and the adverse effects.

METHODS

For the review, clinical studies with cross-over and parallel-arm randomized controlled trials (RCTs) were searched in seven electronic databases, followed by cross-referencing of the selected studies and related research synthesis. Risk of bias (RoB) assessment was carried out with Cochrane's RoB tool and a random-effects model was used. The meta-analysis was performed with the RevMan software 5.4.1.

RESULTS

Eleven eligible RCTs were incorporated into the review and eight RCTs into the meta-analysis, of which five had high RoB and the remaining six had unclear RoB. Following meta-analysis, no significant difference in postoperative pain was found among the EAL and radiograph groups (SMD 0.00, CI .29 to .28, 354 participants; P value = 0.98). Radiograph group showed better WL accuracy (SMD 0.55, CI .11 to .99, 254 participants; P value = 0.02), while the EAL group had 10% better WL adequacy (RR 1.10, CI 1.03-1.18, 573 participants; P value = 0.006).

CONCLUSION

We found very low-certainty evidence to support the efficacy of different types of EAL compared to radiography for the outcomes tested. We were unable to reach any conclusions about the superiority of any type of EAL. Well-planned RCTs need to be conducted by standardizing the outcomes and outcome measurement methods.

A 22-year follow-up cross-sectional study on periapical health in relation to the quality of root canal treatment in a Belgian population

AIM

To investigate the prevalence of apical periodontitis (AP) and the technical standard of root canal treatment in a Belgian population, assess the association of different variables with periapical status, and compare the results to a similar study conducted 22 years previously.

METHODOLOGY

In this cross-sectional study, 614 panoramic radiographs of first-time adult attendees at the Dental School of the University Hospital of Ghent were examined. Recorded patient-level parameters included gender, age, number of teeth, number of root filled teeth, presence of any AP lesion, and number of implants. The following tooth-level data were collected: tooth presence, coronal status, quality of coronal restoration, post presence, type of root-filling material, length and density of root filling, root-end filling material, presence of AP, and adjacent implant. Multivariable multilevel binary logistic regression was used to explore the association between patient and tooth characteristics and AP prevalence. Risk differences and confidence intervals were calculated to compare the present with the previous study.

RESULTS

The prevalence of AP at patient and tooth level was 46.9% and 5.6%, respectively. Fifty-one per cent of the 614 patients had at least one root filled tooth, and 5.9% of the 14 655 teeth studied were root filled. AP was found in 45% of root filled teeth. Fifty-four per cent of the root-filled teeth were rated as inadequate. Multivariable multilevel logistic regression revealed that more teeth, more implants, fewer root-filled teeth, adequate density, adequate coronal restoration, and no caries reduced the likelihood of AP. There were no statistically significant differences between the two studies regarding the prevalence of root-filled teeth or AP and the technical quality of root canal treatment.

CONCLUSIONS

The prevalence of AP and the technical quality of root canal treatment in Belgium have not substantially changed over the last 22 years, despite the technological advancements and continuing education in the field.

The association of endodontic prognostic factors with the presence of periapical lesion, its volume, and bone characteristics in endodontically treated molars: a cross-sectional study

BACKGROUND

This study intended to evaluate the association between several endodontic prognostic factors with the presence of periapical lesions (PLs), their volume, and bone characteristics including cortical bone destruction (CBD) and buccal plate bone height (BPBH) in root-filled molar teeth using cone-beam computed tomography.

METHODS

A collection of 143 scans of endodontically treated maxillary/mandibular first or second molars recorded over 8 years, were obtained from a specialized radiology center. Data on prognostic factors including tooth number, gender, jaw type, the status and number of missed canals, obturation length, restoration type, presence of a separated instrument, presence of a post or screw in the canals, and presence of perforation were collected. The assessed outcomes included PL presence, PL volume, CBD, and BPBH. The association between prognostic factors and outcomes was evaluated using multiple logistic regression models with adjusted covariates and multifactorial ANOVA at a significance level of 0.05.

RESULTS

A total of 282 molars from 82 women and 50 men with a mean age of 40.6 ± 12.27 were included. Among those, 139 teeth presented PL with a mean volume of 18.68 mm3. CBD was prevalent in 137 teeth and the mean BPBH appeared to be 9.45 mm. The presence of a missed canal (OR = 10.022, P < .05), underfilled canal (OR = 3.725, P < .05), overfilled canal (OR = 15.859, P = .018), and perforation (OR = 15.261, P = .013) was significantly associated with PLs. None of the prognostic factors could considerably contribute to the CBD (P > .05). The presence of a missed canal was positively associated with the PL volume (P < .05). Similarly, missed canals (P < .05), perforation (P < .05), and separated instruments (P = .004) were associated with a significantly reduced BPBH.

CONCLUSIONS

Overfillings, perforations, missed canals, and underfillings were identified as remarkable predictors of PL, arranged in descending order of their respective impact. The only factor capable of significantly increasing the PL volume was the missed canal. In brief, obturation length errors, perforations, missed canals, and separated instruments were robustly correlated with endodontic failure, which highlights the importance of mitigating the potential for errors by following the fundamentals of endodontics.

The effect of root canal treatment and post-crown restorations on stress distribution in teeth with periapical periodontitis: a finite element analysis

AIM

To evaluate the effects of root canal treatment (RCT) and post-crown restoration on stress distribution in teeth with periapical bone defects using finite element analysis.

METHODOLOGY

Finite element models of mandibular second premolars and those with periapical bone defects (spherical defects with diameters of 5, 10, 15, and 20 mm) were created using digital model design software. The corresponding RCT and post-crown restoration models were constructed based on the different sizes of periapical bone defect models. The von Mises stress and tooth displacement distributions were comprehensively analyzed in each model.

RESULTS

Overall analysis of the models: RCT significantly increased the maximum von Mises stresses in teeth with periapical bone defects, while post-crown restoration greatly reduced the maximum von Mises stresses. RCT and post-crown restoration slightly reduced tooth displacement in the affected tooth. Internal analysis of tooth: RCT dramatically increased the maximum von Mises stress in all regions of the tooth, with the most pronounced increase in the coronal surface region. The post-crown restoration balances the internal stresses of the tooth and is most effective in periapical bone defect - 20-mm model. RCT and post-crown restoration slightly reduced the tooth displacement in all regions of the affected tooth.

CONCLUSIONS

Root canal treatment seemed not to improve the biomechanical state of teeth with periapical bone defects. In contrast, post-crown restoration might effectively balance the stress concentrations caused by periapical bone defects, particularly extensive ones.

Cost-effectiveness analysis of full versus selective root canal retreatment

AIM

Selective root-canal retreatment has been proposed as an alternative to full retreatment in multirooted, root-canal-filled teeth with evidence of apical pathology, where only the affected root(s) is retreated. Whilst this option may save costs initially, failures and retreatments may compensate for these initial savings. We assessed the cost-effectiveness of full versus selective root-canal retreatment using data from a recent clinical pilot study, employing a modelling approach.

METHODOLOGY

A Markov model was constructed to follow up a previously root-canal treated maxillary molar with apical pathology on a single root (mesio-buccal), receiving either selective or full root-canal retreatment. A private-payer perspective in Dutch health care was adopted. Permanent molar teeth with apical lesions on the mesial root were simulated over the lifetime of initially 50-year-old patients. Teeth could have endodontic complications and require interventions such as retreatment or tooth extraction and replacement. Costs were calculated based on the Dutch dental fee catalogues. Monte-Carlo microsimulations were performed to assess lifetime costs and effectiveness (measured as tooth retention time), and the resulting cost-effectiveness. Probabilistic joint uncertainty and sensitivity analyses were performed, and cost-effectiveness at different willingness-to-pay-thresholds was evaluated.

RESULTS

In the base-case scenario, selective retreatment was less costly (2137; 2.5%-97.5% percentiles: 1944-2340 Euro) and more effective (19.6; 18.3-20.8 Years) than full retreatment (2495; 2305-2671 Euro; 16.5; 15.2-17.9 Years) in 100% of the simulations and regardless of the willingness-to-pay threshold. Only in a worst case scenario was selective retreatment more costly, but remained more effective.

CONCLUSIONS

Selective retreatment, when clinically applicable, is likely to be more cost-effective than full retreatment in endodontically treated molars with persistent apical periodontitis. Our results should be interpreted with caution because the quality of the underlying data is limited.

Endodontic Orthograde Retreatments: Challenges and Solutions

Endodontic orthograde retreatments are considered one of the possible treatment options in case of post-treatment diseases considering the promising results present in the literature. Despite this, a plethora of articles have been published on this topic, and drawing conclusions could be challenging. For this reason, this review aims to summarize the crucial points on each aspect of non-surgical endodontic retreatments, discussing and comparing the current protocols, techniques, materials, and indications. Taking into consideration data from the literature, in terms of diagnosis, CBCT should be considered the first choice, since it can thoroughly affect the diagnosis and treatment plan. Regarding the procedural phases, some conclusions can be drawn: when present, coronal restoration materials such as crowns, partial prostheses, post, and core should be removed; the use of magnification devices, ultrasonic instruments, and an in-depth interpretation of radiographic images with both 2D and 3D images are strongly recommended during the orifice location; additional protocols such as irrigants activation, ultrasonic cleaning, and rotary or reciprocating instrumentation of treated canals are strongly recommended for filling materials removal and to achieve a high-quality chemo-mechanical disinfection; perforations should be treated as soon as possible, and the material of choice to treat them is the MTA or other calcium-silicate-based repair materials; the presence of ledges does not intrinsically reduce the success rate of RCRts if properly managed; in case of instrument fragments, their removal should be considered as the first treatment option, however many variables should be considered to select the proper technique or consider the option of bypassing.

Machine Learning to Predict Apical Lesions: A Cross-Sectional and Model Development Study

(1) Background: We aimed to identify factors associated with the presence of apical lesions (AL) in panoramic radiographs and to evaluate the predictive value of the identified factors. (2) Methodology: Panoramic radiographs from 1071 patients (age: 11-93 a, mean: 50.6 a ± 19.7 a) with 27,532 teeth were included. Each radiograph was independently assessed by five experienced dentists for AL. A range of shallow machine learning algorithms (logistic regression, k-nearest neighbor, decision tree, random forest, support vector machine, adaptive and gradient boosting) were employed to identify factors at both the patient and tooth level associated with AL and to predict AL. (3) Results: AL were detected in 522 patients (48.7%) and 1133 teeth (4.1%), whereas males showed a significantly higher prevalence than females (52.5%/44.8%; p < 0.05). Logistic regression found that an existing root canal treatment was the most important risk factor (adjusted Odds Ratio 16.89; 95% CI: 13.98-20.41), followed by the tooth type 'molar' (2.54; 2.1-3.08) and the restoration with a crown (2.1; 1.67-2.63). Associations between factors and AL were stronger and accuracy higher when using fewer complex models like decision tree (F1 score: 0.9 (0.89-0.9)). (4) Conclusions: The presence of AL was higher in root-canal treated teeth, those with crowns and molars. More complex machine learning models did not outperform less-complex ones.

Retrospective Analysis of Artifacts in Cone Beam Computed Tomography Images Used to Diagnose Chronic Rhinosinusitis

BACKGROUND

Cone beam computed tomography (CBCT) is frequently used to corroborate the signs and symptoms of chronic rhinosinusitis (CRS). However, artifacts induced by dental restorations might complicate the diagnosis of CRS. Here, we assessed the frequency and location of artifacts in CBCT images taken to confirm the CRS.

METHODS

All CBCT images of the patients referred to the Emergency Radiology unit, Turku University Hospital, with an indication of CRS in 2017 were re-examined. The prevalence of the artifacts was analyzed in three cross-sectional views and three horizontal levels delimited by anatomical landmarks.

RESULTS

In total, 214 CBCT images of patients with CRS were evaluated. The diagnosis of apical periodontitis (AP) was impaired by artifacts present in 150/214 images (70%). The diagnosis of CRS was impaired in 5 of the 214 images (2.3%). The main origins of the artifacts were large dental fillings or crowns, and endodontic fillings were present in 95% (203/214) and 52% (111/214) of the images, respectively.

CONCLUSIONS

AP as an etiology of CRS is possible to miss because of artifacts originating from dental and endodontic fillings in the CBCT images of the paranasal sinuses.

Recent Advances in Apical Periodontitis Treatment: A Narrative Review

Apical periodontitis is an inflammatory response caused by pulp infection. It induces bone resorption in the apical and periapical regions of the tooth. The most conservative approach to treat this condition is nonsurgical endodontic treatment. However, clinical failure has been reported with this approach; thus, alternative procedures are required. This review highlights recent literature regarding advanced approaches for the treatment of apical periodontitis. Various therapies, including biological medications, antioxidants, specialized pro-resolving lipid mediators, and stem cell therapy, have been tested to increase the success rate of treatment for apical periodontitis. Some of these approaches remain in the in vivo phase of research, while others have just entered the translational research phase to validate clinical application. However, a detailed understanding of the molecular mechanisms that occur during development of the immunoinflammatory reaction in apical periodontitis remains unclear. The aim of this review was to summarize advanced approaches for the treatment of apical periodontitis. Further research can confirm the potential of these alternative nonsurgical endodontic treatment approaches.

Outcome of selective root canal retreatment-A retrospective study

AIM

Selective root canal retreatment is when the treatment is limited to root(s) with radiographic evidence of periapical pathosis. The goals of this retrospective study were as follows: (i) evaluate the clinical and radiographic (periapical radiographs [PR] or cone-beam computerized tomographs [CBCT]) outcome of selective root canal retreatment after ≥12 months follow-up; (ii) evaluate the periapical status of the unretreated roots; and (iii) assess tooth survival.

METHODOLOGY

A retrospective study (January 2018 to April 2021) was conducted to identify permanent multirooted teeth that underwent selective root canal retreatment. Clinical records, PR and CBCT were examined to ascertain variables of interest. Outcomes (per root and per tooth) were classified into 'favourable' or 'unfavourable' using well-established clinical and radiographic healing criteria. Treatment outcomes for the whole tooth and per root were compared as well as bivariate associations between the treatment outcome of the retreated roots and the treatment-related parameters (quality of root filling, sealer extrusion, iatrogenic mishaps and type of restoration) were analysed using Fisher's exact test (α = .05). Survival was recorded in months.

RESULTS

A total of 75 teeth (195 roots) in 75 subjects were available for outcome analysis. The favourable outcome per tooth was 86.7%. At follow-up, 92.6% of the retreated roots had a favourable outcome. From the unretreated roots, 3.5% showed radiographic signs of an emerging periapical lesion. No statistical difference was shown between the outcomes per root and per tooth between both groups. None of the treatment-related parameters had a direct influence on the outcome of the retreated roots. The survival rate at 12-48 months after retreatment was 91.5%.

CONCLUSIONS

Selective root canal retreatment is associated with a favourable outcome in a majority of cases. Unretreated roots rarely developed radiographic signs of a new periapical lesion at follow-up. Future high-quality clinical trials with larger sample sizes and longer follow-up periods are required to confirm these findings.

Low-Diversity Microbiota in Apical Periodontitis and High Blood Pressure Are Signatures of the Severity of Apical Lesions in Humans

(1) Background: In developed countries, the prevalence of apical periodontitis (AP) varies from 20% to 50% for reasons that could be associated with the apical periodontitis microbiota ecology. (2) Methods: We performed a clinical study in the Odontology department of Toulouse hospital in France, to sequence the 16S rRNA gene of AP microbiota and collect clinical parameters from 94 patients. Forty-four patients were characterized with a PAI (periapical index of AP severity) score lower or equal to 3, while the others had superior scores (n = 50). (3) Results: The low diversity of granuloma microbiota is associated with the highest severity (PAI = 5) of periapical lesions (Odds Ratio 4.592, IC 95% [1.6329; 14.0728]; p = 0.001; notably, a lower relative abundance of Burkholderiaceae and a higher relative abundance of Pseudomonas and Prevotella). We also identified that high blood pressure (HBP) is associated with the increase in PAI scores. (4) Conclusions: Our data show that a low diversity of bacterial ecology of the AP is associated with severe PAI scores, suggesting a causal mechanism. Furthermore, a second risk factor was blood pressure associated with the severity of apical periodontitis.

Prevalence of Periapical Radiolucency and Conventional Root Canal Treatment in Adults: A Systematic Review of Cross-Sectional Studies

Cross-sectional studies assess a population's health state and the prevalence of diseases or treatments. Few systematic reviews regarding the prevalence of periapical radiolucency (PARL) and nonsurgical root canal treatment (NSRCT) were conducted in the last decade. The goal of this study was to collect and review all updated and available cross-sectional studies that focus on the prevalence of both PARL and NSRCT in adult populations. It involves a systematic literature review of cross-sectional studies on the prevalence of PARL and NSRCT published from 1987 to 2022 in PubMed, Google Scholar, Web of Science, and Scopus with specific keywords used in the search process. A total of 52 articles were included in this systematic review. The majority of the included articles were from different populations. The overall prevalence of teeth with PARL was 43,522 (6.40%), while the prevalence of NSRCT teeth was 52,149 (7.67%). On the other hand, the overall prevalence of PARL in teeth that have received endodontic treatment and teeth that have not received endodontic treatment were 22,110 (3.25%) and 21,412 (3.15%), respectively. A meta-analysis was not performed due to underreporting of publication bias and the high degree of heterogeneity between studies. The overall risk of bias assessment revealed a low risk of bias in 25 (48%) of the included studies. The prevalence of NSRCT was higher at 7.67%, followed by PARL at approximately 6.40%. However, future studies are recommended to investigate the prevalence of both PARL and NSRCT in different patient populations.

Prevalence of apical periodontitis in endodontically-treated maxillary and mandibular posterior teeth in a Saudi Arabian population: a cone-beam computed tomography study

OBJECTIVE

The aim of this retrospective study was to assess the prevalence of apical periodontitis (AP) in root canal-treated maxillary and mandibular posterior teeth in a Saudi Arabian population based on findings from images taken using cone-beam computed tomography (CBCT).

METHODS

The sample included 300 CBCT images from patients (150 females and 150 males) aged between 18 and 80 years old and they were analyzed to detect AP in endodontically treated maxillary and mandibular premolars and molars. Also, the correlation between the prevalence of AP and gender along with location (right/left side of jaw) were analyzed. Periapical lesions were defined as lamina dura gaps appearing disrupted around the width of periodontal ligament and apex at the apical third of the roots.

RESULTS

There was higher prevalence of AP in maxillary (19.1%) when compared to mandibular posterior teeth (17.3%). Mandibular first and maxillary second molars were the most affected teeth with AP (P = 0.05 and P = 0.04, respectively). Also, there was higher prevalence of AP cases with a predilection toward males (Maxillary P = 0.005; Mandibular P = 0.00) and on the right side of the mandibular jaw (P = 0.03).

CONCLUSION

In this study, the prevalence of AP had a significant association between gender with a predilection in males and location with a tendency to occur on the mandibular right side as observed in endodontically treated maxillary and mandibular posterior teeth using CBCT.

Evaluation of endodontically treated teeth and related apical periodontitis using periapical and endodontic status scale: Retrospective cone-beam computed tomography study

The purpose of this study was to evaluate the technical treatment quality and the status of apical pathology of endodontically treated teeth, as well as apical periodontitis (AP) prevalence, in a Turkish population using cone-beam computed tomography (CBCT). The CBCT images obtained between January 2018 and April 2020 were retrospectively examined. The quality of the endodontic treatments and the related periapical inflammatory lesions were classified according to the periapical and endodontic status scale (PESS). The data were statistically analysed using logistic regression, crosstabs and chi-square tests. AP was detected in 41% of 429 endodontically treated teeth. The prevalence of AP was significantly higher in teeth with inadequate root canal treatment compared with those with adequate treatment, 70.8% and 29.3%, respectively. Inadequate canal length and homogeneity, and complications were significantly associated with the prognostic periapical status scores of higher risk.

Prevalence of root canal treatment worldwide: A systematic review and meta-analysis

BACKGROUND

The prevalence of root filled teeth (RFT) worldwide will inform about the amount of clinical activity of dentists dedicated to treat endodontic disease.

OBJECTIVES

To carry out a systematic review with meta-analysis answering the following question: What is the prevalence of RFT around the world? The percentage of people with at least one RFT was also investigated.

METHODS

A systematic review including population-based studies using the following databases: PubMed, EMBASE and Scielo. Studies related to prevalence of RFT were included. The outcome of interest of the study was the prevalence of RFT. The meta-analyses were calculated with the Open Meta Analyst software to determine the global prevalence of RFT. Subgroups analyses were performed comparing geographical distribution, radiographic method and year of the study (classified in 20th or 21th century). The prevalence of people with at least one RFT was also analysed.

RESULTS

Seventy-four population-based studies fulfilled the inclusion criteria. Twenty-eight, forty-four and two studies reported high, moderate and low risk of bias, respectively. No obvious publication bias was observed. Prevalence of RFT was estimated with 1 201 255 teeth and 32 162 patients. The calculated worldwide prevalence of RFT was 8.2% (95% CI = 7.3%-9.1%; p < .001). The global prevalence of people with at least one RFT was 55.7% (95% CI = 49.6%-61.8%; p < .001). In 20th century, the prevalence of RFT was 10.2% (95% CI = 7.9%-12.5%; p < .001), whereas in the 21st century the overall calculated prevalence of RFT was 7.5% (95% CI = 6.5%-8.6%; p < .001). Brazilian people (12%) and the European population (9.3%) showed the highest prevalence of RFT. In Europe, 59.6% (95% CI = 52.4%-66.8%) of people has at least one RFT.

CONCLUSIONS

This review showed that root canal treatment is a very common therapy throughout the world. More than half of the studied population have at least one RFT. A limitation of the present study is that most of the studies did not consider random sampling for population selection.

REGISTRATION

PROSPERO Systematic review registration number: (CRD42022329053).

Assessment of the coronal root canal morphology of permanent maxillary first molars using digital 3D-reconstruction technology based on micro-computed tomography data

Background

The design of minimally invasive access has become a hotspot. This study aimed to evaluate the coronal root canal morphology of permanent maxillary first molars to facilitate the design of endodontic access cavities for minimally invasive linear access.

Materials and methods

A selection of 91 permanent maxillary first molars was evaluated. Three-dimensional tooth models were reconstructed using micro-computed tomography data. Root canal prevalence and coronal root canal landmarks were recorded. The positional coordinates of landmarks in the horizontal plane and the angles and directions of coronal root canal curvature in the horizontal and axial planes were also assessed.

Results

The detection rates of the mesiobuccal (MB), distobuccal (DB), and palatal (P) canals were 100%, whereas that of the second mesiobuccal (MB2) canals was 68.1%. All landmarks were located near the central fossa. In the axial plane, the average angles of coronal root canal curvature were DB (27.05°) > MB (25.43°) > P (20.71°) in teeth with three canals, and MB2 (33.20°) > MB (29.61°) > DB (28.40°) > P (23.69°) in teeth with four canals. In the horizontal plane, the average angles were P (78.15°) > DB (42.34°) > MB (32.41°) in teeth with three canals, and P (81.26°) > DB (43.44°) > MB (41.22°) > MB2 (9.41°) in teeth with four canals.

Conclusion

In maxillary first molars, coronal root canals tend to converge towards the occlusal surface. The results of this study could be applied to improve the precision of endodontic access cavity designs of minimally invasive access.

Periapical and endodontic status among 65-year-old Oslo-citizens

Aim

This cross-sectional study aimed to investigate the prevalence of apical periodontitis (AP) and root-filled teeth in a 65-year-old population in Oslo, Norway, and to investigate associations of pathosis and endodontic treatment with selected individual risk indicators and technical quality of root fillings.

Material and methods

A random sample of 450 65-year-olds in Oslo answered a questionnaire and underwent a clinical and radiological examination (52% men and 48% women). Periapical radiographs were taken of all root-filled teeth and of teeth with apical radiolucency, and periapical status was evaluated using the Periapical Index. Apex-to-filling distance and homogeneity were assessed for all root fillings. Analyses on individual level and tooth level were performed. The outcome variables were ‘non-root-filled tooth with AP’ (‘untreated AP’), ‘root-filled tooth’, and 'root-filled tooth with AP’. The explanatory variables were gender, education, dental attendance pattern, smoking, remaining teeth (n), tooth group, and root filling quality. Chi-square test and logistic regression analyses were used to assess the associations between outcome variables and explanatory variables. The level of significance was set to p < 0.05.

Results

The mean number of remaining teeth was 26 (SD: 4). AP was present in 45% of the individuals. Sixteen percent of the individuals had untreated AP and 38% had at least one root-filled tooth with AP. Sixty-six percent of the individuals had one or more root-filled teeth. Untreated AP was significantly associated with a decreasing number of remaining teeth and smoking. All the outcome variables were significantly more prevalent in molars compared with premolars and anterior teeth. Thirty-five percent of the root-filled teeth had AP, and AP was more prevalent in teeth with too short apex-to-filling distance (53%) or unsatisfactory homogeneity (46%).

Conclusions

The remaining number of teeth was high, and AP and root-filled teeth were prevalent in the present young-elderly population. A notable amount of untreated AP was observed, especially in smokers. The findings in the present study indicate a substantial need for dental care associated with endodontic conditions in the future elderly.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02406-9.

Stylohyoid Ligament Calcification and Its Association With Dental Diseases

OBJECTIVES

This research aimed at investigating the relationship between calcification of the stylohyoid ligaments (SHLs) and odontogenic inflammatory events.

METHODS

Cone-beam computed tomography scans of 175 patients were retrospectively assessed for presence of SHL calcifications. Frequencies of 4 types of odontogenic inflammatory events were assessed using the same scans, namely dental extractions, root canal treatments, furcation lesions, and periapical lesions. Patients were telephone-interviewed and asked about histories of tonsillectomy and head and neck trauma. Mann-Whitney U and binary logistic regression tests were used to assess associations between SHL calcification and mean ranks of odontogenic inflammatory events.

RESULTS

Calcification of SHLs was detected in 71 (41%) and 58 (33%) patients on the right and left sides, respectively. Tonsillectomy and trauma were reported in 14% and 10% of the sample, respectively. Amongst all inflammatory events, root canal treatments were significantly associated with SHL calcification (U = 2755; Z = -2.1; P = .035). This association was independent from patient age, tonsillectomy, trauma, and other inflammatory events (odds ratio, 1.2; 95% confidence interval, 1.0-1.4; P = .036).

CONCLUSIONS

This study presents new evidence that intra-oral inflammatory events, particularly related to root canal treatments, have a stronger association with SHL dystrophic calcification than that associated with traditional predisposing factors (ie, old age, tonsillectomy, and trauma).

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.

In vitro assessment of periapical lesions created in sheep mandibles by using high resolution ultrasonography and cone beam computed tomography

OBJECTIVES

Providing ultrasound images of periapical lesions may be problematic depending on the thickness of the overlying cortical bone. Clinically, it is crucial to determine the cut-off value of overlaying bone thickness in terms of interference with ultrasound imaging in conjunction with assessment of changes in periapical jaw bone lesions. Our aim was to determine the minimum amount of overlaying buccal bone thickness of artificial periapical lesions in order to be visible by ultrasound imaging and to compare width, height, depth, surface area and volume measurements of detectable periapical lesions obtained from ultrasound and CBCT images.

METHODS

Periapical lesions were created in 16 molar teeth of sheep mandibles. Cavities were enlarged until the borders of lesions were visible on 14 MHz hockey probe ultrasound imaging. CBCT and ultrasound images were obtained simultaneously after drilling and enlarging each size of the cavities and replacing the teeth in their sockets. two observers separately assessed images twice within 2 weeks of interval. By using CBCT and ultrasound images, buccal bone thickness, maximum width, height, depth, surface area and volume of periapical lesions were measured. Intraclass correlation coefficient (ICC) was utilized and significance level was set at p < 0.05.

RESULTS

The mean buccal bone thickness ranged between 1.21 mm and 1.31 mm for both imaging techniques. For the measurement of buccal bone thickness, periapical lesion width, height, depth, surface area, and volume excellent ICC values were found in terms of intrarater (ranging between 0.907 and 1) and inter-rater (ranging between 0.864 and 1) reliability for both observers and their readings. There were no statistically significant differences for both observers and for their two readings between ultrasound and CBCT measurements of buccal bone thickness, and periapical lesion width and height (p > 0.05).

CONCLUSIONS

We suggested that a buccal thickness of approximately 1.28 mm might be accepted as a cut-off value for the detection of periapical lesions with 14 MHz hockey probe ultrasound. High resolution ultrasound provided accurate information for the measurement of buccal bone thickness and lesion width and height.

Periodontal and Periapical Outcomes of Surgical Extrusion: A Prospective Clinical Volumetric Study

INTRODUCTION

Outcome predictors for the restoration of endodontically treated teeth mainly include cavity wall integrity and the presence of a 1.5-2 mm ferrule. However, in some clinical situations, the aforementioned predictors cannot be achieved. Three different techniques have been proposed to obtain an adequate ferrule respecting the supracrestal tissue attachment: surgical crown lengthening, orthodontic forced eruption, and surgical extrusion. There are little published prospective data evaluating periodontal changes after surgical extrusion. Therefore, the aims of this study were to report the outcome of surgical extrusion in single-rooted teeth, to digitally evaluate soft tissue volumetric changes after surgical extrusion, and to observe patient satisfaction regarding the treatment after a minimum of 1 year.

METHODS

This prospective clinical study was performed between 2017 and 2020. Thirteen patients referred for surgical extrusion met the following inclusion criteria: nonsmokers; systemically healthy with at least 1 straight, single-rooted tooth with an insufficient ferrule; a favorable tooth crown-to-root ratio, and no periodontal pathology. Preoperative clinical variables included patient age, sex and phenotype, tooth number, tooth mobility, crown-to-root ratio, gingival index (GI), probing pocket depths at 6 sites, bleeding on probing (BOP), and mesial and distal interproximal papillae volume. Surgical extrusion was performed by a single operator who completed the root canal treatment/retreatment and restored the teeth with a crown. One year later, all patients were controlled, and the following variables were recorded: tooth mobility, crown-to-root ratio, GI, pocket depth, BOP, interproximal papillae aspect, soft tissue rebound, periapical healing, marginal bone loss, and patient-reported outcome measures of the treatment. All variables were analyzed using a descriptive method (mean, %). The Wilcoxon test was used to evaluate pre- and postoperative clinical parameters at a significance level of .05.

RESULTS

At a mean follow-up period of 18.8 months, no teeth were extracted. Compared with preoperative GI and BOP, a significant reduction was observed at 1 year after surgery. Likewise, no significant differences in probing depths were shown, and only 1 tooth presented a type 2 mobility. The mean soft tissue rebound was -0.46 ± 0.69 mm. Overall, no significant interproximal papillae height loss was observed.Apical lesions were completely healed after surgery. The tooth crown-to-root ratio was favorable in all cases before extrusion, whereas in 3 cases it was appropriate (1 = 1), and only 1 case presented >25% of marginal bone loss during the follow-up period. The reported success rate was 92.3%, and patients were generally satisfied with the outcome.

CONCLUSIONS

Surgical extrusion of single-rooted teeth was successful with minimal or no soft tissue loss, and patients were satisfied with the surgical procedure and the esthetic result.

Effects of an individualized training course on technical quality and periapical status of teeth treated endodontically by dentists in the Public Dental Service in Norway: An observational intervention study

AIM

To investigate the effect of a continuing education course on technical quality and treatment outcome for root filled permanent teeth in Møre and Romsdal County, Norway.

METHODOLOGY

Fifty-two dentists employed in the Public Dental Service in Møre and Romsdal county, Norway, completed a two-day continuing education course in root canal treatment. Periapical radiographs of root filled teeth treated before and after the course, with at least one-year follow-up were identified and scored for technical quality and periapical status. Technical root filling quality was assessed by density and length and the treatment outcome by PAI scores. Treatment information was achieved from the county's electronic dental record system. Information regarding the dental practitioners' background and treatment procedure routines was collected by a questionnaire. Descriptive statistics analyses and mixed-effect logistic regression analyses were performed to evaluate the effect of the course.

RESULTS

Radiographs were available for 224 teeth root filled before and for 221 teeth after the course. The proportion of teeth with adequate root filling quality was significantly lower after the course (p = .006), associated mainly with short root fillings (p < .001). No significant differences were observed in treatment outcome. There were, however, large differences in treatment outcome amongst subgroups of dentists. Further, there was evidence of effect modification by the continuing education course on periapical outcome by patient's age (p_interaction  = .0023) suggesting that teeth in patients ≤18 years healed relatively better post-course compared to patients >18 years.

CONCLUSIONS

A two-day continuing education course in root canal treatment attended by Public Dental Service dentists in Norway did not improve the technical quality of root fillings or periapical status associated with root filled teeth.

AGMB-Transformer: Anatomy-Guided Multi-Branch Transformer Network for Automated Evaluation of Root Canal Therapy

Accurate evaluation of the treatment result on X-ray images is a significant and challenging step in root canal therapy since the incorrect interpretation of the therapy results will hamper timely follow-up which is crucial to the patients' treatment outcome. Nowadays, the evaluation is performed in a manual manner, which is time-consuming, subjective, and error-prone. In this paper, we aim to automate this process by leveraging the advances in computer vision and artificial intelligence, to provide an objective and accurate method for root canal therapy result assessment. A novel anatomy-guided multi-branch Transformer (AGMB-Transformer) network is proposed, which first extracts a set of anatomy features and then uses them to guide a multi-branch Transformer network for evaluation. Specifically, we design a polynomial curve fitting segmentation strategy with the help of landmark detection to extract the anatomy features. Moreover, a branch fusion module and a multi-branch structure including our progressive Transformer and Group Multi-Head Self-Attention (GMHSA) are designed to focus on both global and local features for an accurate diagnosis. To facilitate the research, we have collected a large-scale root canal therapy evaluation dataset with 245 root canal therapy X-ray images, and the experiment results show that our AGMB-Transformer can improve the diagnosis accuracy from 57.96% to 90.20% compared with the baseline network. The proposed AGMB-Transformer can achieve a highly accurate evaluation of root canal therapy. To our best knowledge, our work is the first to perform automatic root canal therapy evaluation and has important clinical value to reduce the workload of endodontists.

The quality of root canal treatment and periapical status of permanent teeth in Turkish children and teens: a retrospective CBCT study

OBJECTIVE

This study aimed to assess the quality of root canal fillings and the prevalence of periapical radiolucencies in the permanent teeth of 6-18 year-old Turkish children.

METHODS

CBCT images of 150 patients' 235 teeth with a mean age of 16.0 ± 2.06 years were included. Root development stage, quality of root canal filling, the presence and severity of periapical radiolucencies, and their relationship with anatomical structures were recorded. Correlations between the quality of root canal filling, periapical lesion, and lesion size were assessed using regression analyses.

RESULTS

A total of 235 teeth (528 root canals) were evaluated. 65.5% of root canals had periapical lesions. Immature roots and mandibular teeth had the highest prevalence and the largest size of periapical radiolucencies (p < 0.05). Overfilling (n = 52), underfilling (n = 93), unfilled (n = 46), inhomogeneously filled (n = 113) root canals and poor coronal restoration (n = 85 teeth) were observed in terms of technical failures of endodontic treatment. The quality of endodontic treatment was associated with the presence of periapical lesion and lesion size (p < 0.05). Teeth with under-filled, overfilled or inhomogeneously filled root canals and poor coronal restoration had a periapical lesion larger than 5 mm (p < 0.05). Immature teeth were most associated with the presence of lesion (OR = 4.07) and the lesion size > 5 mm (OR = 3.71).

CONCLUSION

The prevalence of periapical radiolucencies in young permanent teeth showed an increase when the tooth was an incisor, had incomplete root development, or the root filling had technical errors.

Prevalence of periapical lesions, root canal treatments and restorations in teeth adjacent to implant- or tooth-supported crowns: A multi-centre cross-sectional study

AIM

To describe the prevalence of periapical lesions, root canal treatments and coronal restorations on teeth adjacent to either implant- or natural tooth-supported crowns using cone-beam computed tomography (CBCT) assessment compared to nonadjacent teeth.

METHODOLOGY

A total of 1249 CBCT volumes were screened by five pre-calibrated observers in 11 health centres. A step-by-step screening protocol was implemented and reviewed every 3 months, and mandatory setting characteristics were established for all CBCT scans using dedicated visualization software. Intra- and inter-rater reliability tests were conducted. The prevalence of periapical lesions, root canal treatments and coronal restorations was recorded on both teeth adjacent and nonadjacent to implant- (predictor 1) or natural tooth-supported crowns (predictor 2). A binary logistic model (Generalizing Estimating Equations test) was used to verify whether the prevalence of periapical lesion, root canal filling and the tooth restorative status are altered when the assessed tooth is adjacent or not to an implant-supported crown (predictor 1); or to a natural tooth-supported crown (predictor 2). Odds ratio and confidence intervals for the dependent variables at both predictors were obtained. The significance level was set at .05.

RESULTS

A global sample of 22 899 teeth was included. Compared to nonadjacent teeth, the prevalence of periapical lesion, root canals treatments and restorative procedures when adjacent to implant-supported crowns was 10.7%, 19.6% and 22.9% higher, respectively, and when adjacent to tooth-supported crowns was 19.3%, 35.6% and 37.4% higher respectively. These results were significant only for variables root canal filling and coronal restoration (p < .0001). Odds ratio to present root canal treatment is 2.57 times higher (CI 1.95-3.39, p = .0001) when the tooth is adjacent to implant-supported crown and 4.39 times (CI 3.49-5.53, p = .0001) when adjacent to tooth-supported crown, whilst for restorative procedure, the odds are, respectively, 1.63 (CI 1.29-2.06, p = .0001) and 2.30 (CI 1.92-2.76, p = .0001).

CONCLUSIONS

Teeth adjacent to both implant- and natural tooth-supported crowns were associated with a higher frequency of root canal filling and coronal restorations.

A Scoping Review of Four Decades of Outcomes in Nonsurgical Root Canal Treatment, Nonsurgical Retreatment, and Apexification Studies: Part 3-A Proposed Framework for Standardized Data Collection and Reporting of Endodontic Outcome Studies

INTRODUCTION

Despite initiatives to standardize and improve reporting of rapidly growing endodontic outcome research studies, issues related to missing and ambiguous information are still of great concern. In this article, we propose a framework for standardized data collection and a compiled checklist for reporting of various study designs on endodontic outcome.

METHODS

A comprehensive search was carried out to locate randomized controlled trials, cohorts, case-control studies, or case series of >100 patients that reported on endodontic outcomes. We reviewed these articles to develop a Data Collection Template and compiled a checklist for reporting of future endodontic outcome research.

RESULTS

Out of 354 eligible articles previously reported in our scoping review on endodontic outcome studies, 109 articles were selected and screened for study variables or levels of categorization. Our complied Data Collection Template was developed in 19 domains to highlight important demographic, preoperative, intraoperative, and postoperative variables. Because of the specific needs for endodontic outcome literature, we also proposed a compiled checklist (consisting of 4 main domains) to facilitate the reporting of various study designs on endodontic outcome studies. This checklist included simple descriptions of the required items and examples on reporting from published endodontic studies.

CONCLUSIONS

By facilitating the collection and reporting of relevant research data by investigators in private practice and academia, we hope that the proposed Data Collection Template and reporting guideline can highlight the importance of standardization among clinicians and researchers while producing valid scientific information that will support evidence-based treatment decisions.

The effects of endodontic access cavity design on dentine removal and effectiveness of canal instrumentation in maxillary molars

AIM

To evaluate in a laboratory setting, the impact of three designs of endodontic access cavities on dentine removal and effectiveness of canal instrumentation in extracted maxillary first molars using micro-computed tomography (micro-CT).

METHODOLOGY

A total of 30 extracted intact maxillary first molars were selected and scanned by micro-CT with a voxel size of 24 µm and randomly distributed into three groups: the traditional endodontic cavity (TEC) group, the conservative endodontic cavity (CEC) group and the guided endodontic cavity (GEC) group. The pulp chambers of teeth in the groups were accessed accordingly. After root canal preparation, the teeth were rescanned. The volume of dentine removed after canal preparation, the noninstrumented canal areas, canal transportation and centring ratio were analysed. Data were analysed statistically using one-way analysis of variance. Tukey's post hoc test was used for multiple comparisons. The significance level was set at p < .05.

RESULTS

The total volume of dentine removed was significantly greater in the TEC group after root canal preparation (p < .05). No significant differences in the volume of dentine removed occurred between the CEC and GEC groups (p > .05). The volume of dentine removed in the crown, pericervical dentine and coronal third of the canal was significantly lower in CEC and GEC groups when compared to that in the TEC group (p < .05), no difference was observed in the middle third of the canal and apical third of the canal amongst the three groups (p > .05). There was no significant difference in noninstrumented canal area, canal transportation and centring ratio amongst the TEC, CEC and GEC groups (p > .05).

CONCLUSIONS

In extracted maxillary molars tested in a laboratory setting, CEC and GEC preserved more tooth tissue in the crown, pericervical dentine and coronal third of the canal compared with TEC after root canal preparation. The design of the endodontic access cavity did not impact on the effectiveness of canal instrumentation in terms of noninstrumented canal area, canal transportation and centring ratio.

Functional Dental Pulp Regeneration: Basic Research and Clinical Translation

Pulpal and periapical diseases account for a large proportion of dental visits, the current treatments for which are root canal therapy (RCT) and pulp revascularisation. Despite the clinical signs of full recovery and histological reconstruction, true regeneration of pulp tissues is still far from being achieved. The goal of regenerative endodontics is to promote normal pulp function recovery in inflamed or necrotic teeth that would result in true regeneration of the pulpodentinal complex. Recently, rapid progress has been made related to tissue engineering-mediated pulp regeneration, which combines stem cells, biomaterials, and growth factors. Since the successful isolation and characterisation of dental pulp stem cells (DPSCs) and other applicable dental mesenchymal stem cells, basic research and preclinical exploration of stem cell-mediated functional pulp regeneration via cell transplantation and cell homing have received considerably more attention. Some of this effort has translated into clinical therapeutic applications, bringing a ground-breaking revolution and a new perspective to the endodontic field. In this article, we retrospectively examined the current treatment status and clinical goals of pulpal and periapical diseases and scrutinized biological studies of functional pulp regeneration with a focus on DPSCs, biomaterials, and growth factors. Then, we reviewed preclinical experiments based on various animal models and research strategies. Finally, we summarised the current challenges encountered in preclinical or clinical regenerative applications and suggested promising solutions to address these challenges to guide tissue engineering-mediated clinical translation in the future.

Effects of an individualised training course in endodontics on the knowledge and insights of dentists in Public Dental Service in Norway

OBJECTIVE

To evaluate the knowledge and insights of general dental practitioners regarding endodontic diagnosis and treatment principles before and after attending a 2-days continuing education course.

MATERIALS AND METHODS

Sixty-seven dentists employed in the Public Dental Service in Møre and Romsdal county, Norway, were invited to a continuing education course in endodontics. Before and after the course, they answered a questionnaire weighing the importance of factors influencing the prognosis of endodontic treatment. The same questionnaire was answered by specialists in endodontics (n = 56; Spec Group) and a reference group consisting of general dental practitioners from both private and public practice (n = 21; Ref Group). The Test Group answered both before and after the course, while the Spec and Ref Groups completed the questionnaire once. The responses were compared using the Wilcoxon Sign test and Mann-Whitey U test.

RESULTS

Of the 67 dentists in the Test Group, 49 (73%) completed the course and answered both questionnaires. Before attending the course, the Test Group differed significantly from the Spec Group in 18 out of 27 prognostic factors (p ≤ .05). After the course, there was only moderate improvement in the Test Group responses. On only three factors, they agreed significantly more with the specialists than before attending the course (p ≤ .05). After the Test Group participants had attended the course, their responses were comparable to the responses of the Ref Group.

CONCLUSIONS

A two-days continuing education course only marginally improved dentists' level of knowledge and insights regarding the influence of prognostic factors in endodontics.

Prevalence of Lateral Radiolucency, Apical Root Resorption and Periapical Lesions in Portuguese Patients: A CBCT Cross-Sectional Study with a Worldwide Overview

Objective:

Apical periodontitis develops when bacteria, or their by products, migrate from the infected root canal system space to the surrounding apical tissues. The objective of the present multi-center cross-sectional study was to analyze the prevalence of lateral radiolucency, apical root resorption and periapical lesions in 7 districts of Portugal using cone-beam computed tomographic (CBCT) assessment.

Methods:

A total of 1,249 CBCT scans, from 11 dental clinics, were screened. Data regarding 22,899 teeth was included. For each tooth the recorded data was the presence of lateral radiolucency, apical root resorption, periapical lesions, previous root canal treatment, missed root canals, length of root canal filling (short, good or overfilling) and type of coronal restoration (intact tooth, non-restored, filling or crown). Differences between districts were tested using chi-squared. A P<0.05 was considered significant.

Results:

The proportion of lateral radiolucency ranged between 0.0% (Aveiro, Braga and Coimbra) and 0.9% (Lisbon), while the prevalence of apical root resorption ranged from 0.0% (Braga and Coimbra) to 3.0% in Setubal. The nationwide proportion of lateral radiolucency was 0.4%, while for apical root resorption was 1.1%. The prevalence of periapical lesions varied from 4.1% (Braga) and 13.0% (Lisbon) with a nationwide proportion of 10.0%. Significant differences were noted between districts (P<0.05).

Conclusion:

The prevalence of lateral radiolucency and apical root resorption were low in all districts. Root canal filled teeth were associated with higher periapical lesions proportions than non-treated teeth. Independently of the assessed district, the periapical status may be influenced by both quality of the endodontic treatment and coronal restoration.

Prevalence and risk factors of Apical periodontitis in endodontically treated teeth: cross-sectional study in an Adult Moroccan subpopulation

Background

The present study aimed at investigating the prevalence of Apical periodontitis in a Moroccan Adult subpopulation with a non-surgical root canal treatment and to assess associated risk factors including endodontic treatment quality, periodontal health status, coronal restoration cavity design and quality.

Methods

A total of 358 endodontically treated teeth were evaluated after more than 1-year period in a Moroccan subpopulation according to predetermined criteria. Studied parameters were assessed clinically and radiographically. The association between coronal restoration quality, cavity design, periodontal status, root canal filling quality, coronal restoration related features, presence or absence of the opposing dentition and the periapical status was determined. Data were analyzed using chi-square test, odds ratio and logistic regression.

Results

The present study revealed that gingival health, coronal restoration with CL II cavity design, and root canal filling quality influenced periapical status of endodontically treated teeth. Multivariate analysis showed that this association was statistically significant for gingival inflammation (95% CI 1.08–3.91, OR 2.05, p = 0.02), inadequate coronal restoration (95% CI 1.16–4.04, OR 2.16, p = 0.01), inadequate root canal filling length and homogeneity (95% CI 1.24–3.01, OR 1.93, P = 0.004), (95% CI 1.41–4.44, OR 2.50, p = 0.002) respectively.

Conclusions

The present study revealed that inadequate coronal restorations especially with large proximal margins (CL II cavity design) and gingival inflammation increased the risk of apical periodontitis in endodontically treated teeth. Prevalence of Apical periodontitis in the present study was 72.1%.

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

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

Successful management of a tooth with endodontic-periodontal lesion: A case report

BACKGROUND

Endodontic-periodontal lesion is a commonly encountered dental condition. However, the prognosis of the condition varies from good to poor. Some cases are associated with a poor prognosis that requires tooth extraction. This report presents a case of an endodontic-periodontal lesion in a tooth that was successfully treated by root canal treatment.

CASE SUMMARY

A 51-year-old female patient with no medical history complained about persistent pain and discomfort in her left mandibular first molar. Clinical examination showed the left mandibular first molar with poor restoration. It was also associated with underlying necrotic pulp and periodontal involvement. Radiographic examination revealed visible bone defects in the apical and periodontal areas. Based on the findings, the patient was diagnosed with a primary endodontic lesion. A root canal treatment for the endodontic lesion was performed. The patient received a coronal all-ceramic endocrown restoration. A follow-up was arranged to check the prognosis. At the 3 mo follow-up, the clinical and radiography evaluations showed complete disappearance of signs and symptoms and an increase in the radiopacity of the root area.

CONCLUSION

Despite the poor prognosis associated with many endodontic lesions, this case report highlights that a good prognosis is still possible for an endodontic lesion with apical and periodontal bone loss. In this case, it was achieved via successful root canal treatment without the need for periodontal or surgical intervention.

Prevalence of Apical Periodontitis and Conventional Nonsurgical Root Canal Treatment in General Adult Population: An Updated Systematic Review and Meta-analysis of Cross-sectional Studies Published between 2012 and 2020

INTRODUCTION

This study aimed to summarize data on apical periodontitis (AP) and nonsurgical root canal treatment (NSRCT) prevalence and risk factors related to age, gender, and quality of restorative and endodontic treatment in the general population from cross-sectional studies published between 2012 and 2020.

METHODS

An electronic search was performed in the following databases: Web of Science, Scopus, and PubMed. The conducted literature search covered studies published between 2012 and 2020, without restrictions on language. The STROBE and NOS tools were used for quality assessment of the included studies.

RESULTS

Sixteen articles were included in the review. In total, 200,041 teeth were examined. On average, 6.3% of teeth had AP, and 7.4% had NSRCT. Forty-one percent of RCT teeth had AP, and 3.5% of untreated teeth had AP. Female patients were less prone to AP in endodontically treated teeth only, compared with male patients (P < .001). Variable stratification of age subgroups among included studies prevented us from conducting a meta-analysis. An increase in AP frequency was found in teeth with inadequate restorative and endodontic treatment (P < .001 and P < .001, respectively). Because of high heterogeneity, these results should be taken with caution.

CONCLUSIONS

There is an increased AP prevalence in the adult general population compared with data from 2012 (6.3% versus 5.4%) in both endodontically treated (41.3% versus 35.9%) and untreated teeth (3.5% versus 2.1%). In addition, AP developed less frequently in female patients with endodontically treated teeth and in teeth with inadequate compared with adequate restorative and endodontic treatment.

Association between Endodontically Treated Maxillary and Mandibular Molars with Fused Roots and Periapical Lesions: A Cone-beam Computed Tomography Cross-sectional Study

INTRODUCTION

Fused root variations of the root canal system increase the complexity of the inner root canal system anatomy. The aim of the present study was to determine, in in vivo conditions, the proportion of periapical lesions in association with endodontically treated maxillary and mandibular molars with fused roots presenting previous root canal treatment by assessing preexisting data via cone-beam computed tomographic volumes.

METHODS

A total of 1160 CBCT scans with an overall sample of 20,836 teeth were screened. A global count of 3701 maxillary molars and mandibular second molars were included in the study. The Cohen kappa test and interclass correlation coefficient tested the intra- and interrater reliability, respectively. The percentage of periapical lesions associated with molars with or without root fusion was determined. Proportions were expressed with 95% confidence intervals (CIs). The z test for proportions was used to analyze differences between subgroups, and an odds ratio was calculated in order to understand the association between periapical lesions and root configuration.

RESULTS

Fused molars presented a prevalence of periapical lesions in endodontically treated teeth of 74.0% (95% CI, 65.2%-82.8%), whereas nonfused molars had a proportion of periapical lesions in root canal-treated teeth of 69.5% (95% CI, 65.2%-73.8%; P > .05). Endodontically treated molars with fused roots presented with 1.3 higher odds of being associated with periapical lesions than endodontically treated molars with nonfused roots.

CONCLUSIONS

A tendency of a higher proportion of periapical lesions was found in the fused rooted molars with a history of root canal treatment when compared with nonfused teeth; however, no statistically significant difference was noted.