Periapical health related to the quality of coronal restorations and root fillings

Advancing Adhesive Strategies for Endodontically Treated Teeth-Part II: Dentin Sealing Before Irrigation Increases Long-Term Microtensile Bond Strength to Coronal Dentin

OBJECTIVE

To compare the long-term microtensile bond strength (μTBS) to coronal dentin using pre-endodontic dentin sealing (PEDS) and post-endodontic adhesion (PEA) techniques under various endodontic irrigation protocols.

MATERIALS AND METHODS

Ten study groups (n = 10) were established based on the timing of adhesive application (PEDS versus PEA) and irrigation protocol: distilled water (control), 3% sodium hypochlorite (NaOCl), 3% NaOCl followed by 17% ethylenediaminetetraacetic acid (EDTA), 3% NaOCl followed by 17% EDTA and 2% chlorhexidine, and a mixture of 3% NaOCl and 9% etidronic acid (HEDP). Specimens underwent μTBS testing after a six-month microspecimen aging period. Fracture patterns were analyzed, and adhesive interfaces were assessed using scanning electron microscopy (SEM). Statistical analysis employed a mixed linear regression model with a 5% significance level.

RESULTS

PEDS consistently preserved high bond strength across all irrigation protocols (57.4-59.5 MPa), while PEA groups treated with endodontic irrigants resulted in significantly lower values (33.3-40.8 MPa; p < 0.001). No significant differences were observed within the PEDS groups (p > 0.05). SEM analysis revealed consistent hybrid layers in PEDS and PEA/Control groups, while PEA groups treated with endodontic irrigation solutions showed significant resin-dentin interface variations and interfacial gaps.

CONCLUSIONS

The PEDS technique preserved high and consistent μTBS regardless of the irrigation protocol, whereas endodontically irrigated PEA groups exhibited significantly reduced bond strength. PEDS offers a predictable approach to optimizing adhesive performance in endodontic-restorative treatments.

CLINICAL SIGNIFICANCE

Integrating PEDS into routine endodontic-restorative workflow is recommended to enhance long-term bond strength to coronal dentin. The PEDS technique ensures consistent adhesive performance regardless of the endodontic irrigation protocol, enhancing restorative predictability and treatment success while preserving tooth structure.

Advancing Adhesive Strategies for Endodontically Treated Teeth-Part I: Impact of Endodontic Irrigation Protocols on the Chemical Composition and Structural Integrity of Coronal Dentin

OBJECTIVE

To evaluate the effects of four endodontic irrigation protocols on the chemical composition and ultrastructure of coronal dentin.

MATERIALS AND METHODS

Coronal dentin fragments were assigned to five study groups: NaOCl (3% sodium hypochlorite), NaOCl/EDTA (3% NaOCl and 17% ethylenediaminetetraacetic acid), NaOCl/EDTA/CHX (3% NaOCl, 17% EDTA and 2% chlorhexidine), NaOCl/HEDP (mixture of 3% NaOCl and 9% etidronic acid), and control (distilled water). Confocal Raman microscopy was employed to analyze the spatial distribution of organic and inorganic components, while attenuated total reflection Fourier transform infrared spectroscopy and energy-dispersive spectroscopy were used to assess the surface composition of dentin. Ultrastructural evaluation was conducted using scanning electron microscopy (SEM). Statistical analysis was performed using a mixed linear model with a significance level of 0.05.

RESULTS

All NaOCl-treated groups showed reduced amide II (p < 0.001), indicating protein degradation. Exclusive NaOCl irrigation yielded the lowest amide II, highest mineral content, and increased phosphate/amide II and carbonate/phosphate ratios (p < 0.05). Chelators reduced mineral content (p < 0.001), with NaOCl/HEDP and NaOCl/EDTA/CHX producing more mineralized surfaces than NaOCl/EDTA and control groups (p < 0.05). A general decrease in organic (C and N) and an increase in inorganic (O, P, and Ca) components occurred across treatments, particularly in NaOCl and NaOCl/HEDP groups. EDTA disturbed the Ca/P equilibrium (p < 0.05). SEM showed a dense smear layer and mostly obliterated tubules in NaOCl and control samples, while chelators reduced the smear layer, partially opened tubules, and caused erosion.

CONCLUSIONS

Exclusive use of 3% NaOCl produces hypermineralized, collagen-depleted coronal dentinal surfaces, with a dense smear layer. Sequential irrigation with 17% EDTA induces stronger demineralization compared to a continuous chelation protocol with 9% HEDP. Both EDTA- and HEDP-treated coronal dentin display partially opened dentinal tubules, signs of erosion, and substantial smear layer reduction.

CLINICAL SIGNIFICANCE

Clinically recommended endodontic irrigation protocols significantly alter the chemical composition and ultrastructural integrity of coronal dentin, the primary substrate for adhesive restorations. These findings enhance the understanding of post-irrigation coronal dentin conditions and their potential implications on the interaction with adhesive restorative materials.

Assessment of the quality of root canal fillings-an ex vivo comparison of CBCT scans, conventional intraoral sensors, and a novel photon-counting sensor

OBJECTIVES

To compare a novel photon-counting sensor, 2 CBCT protocols and 2 CMOS sensors on the detection of gaps between a gutta-percha cone and root canal walls.

METHODS

Twenty-five mandibular incisors were prepared to 45/0.04 (size/taper) at working length. Teeth were placed in a partially dentate mandible and single gutta-percha cones of 7 sizes were placed at length, one at a time, for image acquisition with a photon-counting sensor, 2 CBCT protocols (90 µm3, 120 µm3) and 2 CMOS sensors. Three calibrated observers assessed images for gap presence. Sensitivity, specificity, accuracy, AUC, and agreement with gold standard were determined using ANOVA and Tukey test (P ≤ .05).

RESULTS

Photon-counting sensor showed superior sensitivity and accuracy (88.47%, 81.57%), significantly higher than the CBCT protocols (50.70%-56.33%, 45.87%-53.17%). Contrarily, the photon-counting sensor showed the lowest specificity (40.27%), significantly lower than the CBCT protocols (90.27%, 97.23%). CMOS sensors showed sensitivity, specificity, and accuracy between 72.23%-74.53%, not differing from other modalities. All intraoral sensors showed AUC around 82.87%-84.03%, significantly higher than CBCT protocol 120 µm3 (74.07%). The file size was inversely related to gap size and percentual agreement with gold standard.

CONCLUSIONS

CMOS sensors showed consistent results, while the photon-counting sensor had the highest sensitivity but lacked specificity. CBCT protocols excelled in specificity but had lower sensitivity.

ADVANCES IN KNOWLEDGE

Novel photon-counting sensors and CBCT imaging provided no significant advantage over conventional sensors in assessing gaps as an indicator of quality of root canal filling. Furthermore, smaller gaps were more difficult to detect, regardless of the imaging technique used.

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.

A Comparative Analysis of the Quality of Root Canal Fillings of In Vivo Studies Conducted in Saudi Arabia and Worldwide: A Systematic Review

Aim

Root canal treatment (RCT) is a common procedure practiced daily by dentists worldwide. The current systematic review aimed to evaluate and compare clinical studies on the quality of root canal fillings (RCFs) carried out by dentists with different levels of experience conducted worldwide with those conducted specifically in Saudi Arabia (SA).

Materials and Methods

A full literature search was conducted in Clarivate Analytics' Web of Science, Elsevier's Scopus, Embase, CINHAL, and PubMed, without a restriction to studies published before January 2015. Also, a manual search was carried out by checking papers that may have been missed during the electronic search. The following keywords were used: [(quality of root canal filling(s)) OR (quality of root canal obturation)) and dental practitioners as (general dental practitioners; final year students; endodontist; specialist) AND (root canal obturation) OR (endodontic treatment)]. Parameters of the quality of RCFs, such as length, density, and taper, were assessed and counted.

Results

A total of 13 worldwide and nine SA studies were included in this review, published between 2015 and 2023. Molars were the most treated teeth, at 42.3% and 40.2% for the worldwide and SA studies, respectively. Cases treated by final year students had the highest percentage, at 60.0% for both study groups. The percentages of acceptable quality, with regard to the length, density, and taper of RCFs, were 70.9%, 77.6%, and 84.3%, and 73.2%, 64.6%, and 67.8% for the worldwide and SA studies, respectively.

Conclusion

The overall acceptable quality of RCFs was marginally higher in worldwide studies than in SA studies. Both prevalences can be considered as good, which indicates that the quality of RCFs is moving in the right direction.

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.

Evaluation of calcium hydroxide root canal filling materials by cone beam computed tomography and three-dimensional modeling

AIM

The aim of this study was to compare the effectiveness of filling pastes in resin prototype primary molars by cone beam computed tomography (CBCT) and 3D modeling.

Effects of endodontic irrigation solutions on structural, chemical, and mechanical properties of coronal dentin: A scoping review

OBJECTIVE

This review aims to assess structural, chemical, and mechanical properties of coronal dentin after endodontic irrigation.

MATERIALS AND METHODS

Reporting followed the PRISMA extension for scoping reviews. An electronic search was carried out in PubMed, Embase, and Cochrane Library. Records filtered by language and published up to November 4, 2022 were independently screened by two researchers. Studies evaluating structural, chemical, or mechanical properties of human permanent coronal dentin after irrigation within the scope of nonsurgical root canal treatment were included. Data were extracted regarding study type, sample description and size, experimental groups, outcome, evaluation method, and main findings.

RESULTS

From the initial 1916 studies, and by adding 2 cross-references, 11 in vitro studies were included. Seven studies provide ultrastructural and/or chemical characterization, and six assessed microhardness and/or flexural strength. One percent to 8% sodium hypochlorite (NaOCl) and 1%-17% ethylenediaminetetraacetic acid (EDTA) were the most commonly tested solutions, with contact times of 2-240 min (NaOCl) and 1-1440 min (EDTA) being evaluated.

CONCLUSIONS

Overall, the literature is consensual regarding the inevitable impact of NaOCl and chelating agents on coronal dentin, with both deproteinizing and decalcifying effects being concentration- and time-dependent. The alteration of mechanical parameters further confirmed the surface and subsurface ultrastructural and chemical changes.

CLINICAL SIGNIFICANCE

Endodontic treatment success highly depends on restorative sealing. Understanding the result of exposing coronal dentin, the main substrate for bonding, to irrigants' action is crucial. The deproteinizing and decalcifying effects of NaOCl and chelating agents are both concentration- and time-dependent, causing surface and subsurface ultrastructural, chemical, and mechanical alterations.

Effect of sodium hypochlorite, ethylenediaminetetraacetic acid, and dual-rinse irrigation on dentin adhesion using an etch-and-rinse or self-etch approach

The aim was to investigate the influence of endodontic irrigation solutions and protocols on the micro-tensile bond strength (μTBS) to dentin using an etch-and-rinse (ER) or self-etch (SE) adhesive approach. Eighty extracted human molars were ground to dentin. After pretreating for 27 min (21 min-3 min-3 min) with five different endodontic irrigation protocols (Group 1: NaOCl-EDTA-NaOCl; Group 2: NaOCl-NaOCl-EDTA; Group 3: NaOCl-NaCl-NaOCl; Group 4: Dual Rinse-Dual Rinse-Dual Rinse; Group 5: NaCl-NaCl-NaCl), an ER (Optibond FL, Kerr) or a SE (Clearfil SE Bond, Kuraray) adhesive system was applied. After light-curing, composite build-ups were made and cut into dentin-composite sticks. μTBS and failure modes were analyzed. Nonparametric statistical analyses (α = 0.05) were performed for comparison of the five groups within each type of adhesive as well as between the two adhesive systems used. The use of an ER instead of a SE adhesive system resulted in significantly higher μTBS for all irrigation protocols except for group 1 (NaOCl-EDTA-NaOCl) and 2 (NaOCl-NaOCl-EDTA). A statistical difference between the five different endodontic irrigation protocols was only found within the SE adhesive group, where group 1 (NaOCl-EDTA-NaOCl) achieved highest values. The use of an ER adhesive system cancels out the effect of the endodontic irrigation solution. The highest μTBS was achieved when using a NaOCl-EDTA-NaOCl-irrigation protocol in combination with Clearfil SE Bond, which shows that the selection of the endodontic irrigation should match the corresponding SE adhesive system.

Predicting early endodontic treatment failure following primary root canal treatment

BACKGROUND

Understanding when and why endodontic treatments fail could help clinicians make prognoses and thus improve treatment outcomes. This study was aimed to assess potential predictors of early endodontic treatment failure. We explored factors contributing to the failure of initial root canal treatment were explored, with a specific emphasis on evaluating the influence of the time elapsed since the initial treatment.

METHODS

This retrospective cohort study enrolled 1262 patients who sought endodontic treatment at our department and 175 patients were included for analysis. Potential causes of endodontic treatment failure were investigated, such as inadequate obturation quality, inadequate coronal status, the presence of additional untreated canals, anatomical complexity, instrument separation, iatrogenic perforation, cracks, and endodontic-periodontal lesions. The patients were divided into "short-term" and "long-term" groups depending on the time that had passed since the initial treatment (i.e., < 5 and > 10 years, respectively). The causes of failure in the short-term and long-term group were analyzed and compared using logistic regression analyses. Subgroup analysis was performed according to the number of years since the initial treatment in the short-term group to further investigate the association between the time and cause of failure (i.e., < 1, 2, 3, and 4 years, respectively).

RESULTS

Untreated additional canals were present in 21.7% of all cases, and in 36.9 and 6.4% of cases in the short-term and long-term groups, respectively. Multivariable analysis showed that the presence of untreated additional canals was significantly associated with short-term compared to long-term failure. Untreated additional canals were also associated with endodontic failure within 1, 2, 3, and 4 years.

CONCLUSIONS

The presence of untreated additional canals was a predictor of endodontic failure within 5 years following initial root canal treatment. To optimize long-term prognosis, it is important to detect and treat all root canals during the initial treatment.

Outcome of root canal retreatment filled with gutta-percha techniques: A systematic review and meta-analysis

OBJECTIVE

The present systematic review and meta-analysis aimed to evaluate the success rate of root canal retreatment filled with gutta-percha and the variables related to retreatment success.

DATA

The PRISMA guidelines were followed for the present review. The study protocol was registered in the International Prospective Database of Systematic Reviews (PROSPERO CRD42021283134). Risk assessment was performed using the Newcastle-Ottawa scale. Funnel plots were used to detect publication bias and asymmetry was assessed using Egger's tests.

SOURCES

PubMed, Scopus, ScienceDirect, Cochrane, and additional sources were searched.

STUDY SELECTION

Studies published until 10 December 2022. Clinical studies evaluating the success of root canal retreatment filled with gutta-percha with at least a 1-year follow-up were selected.

RESULTS

Ten studies and one unpublished study fulfilled the inclusion criteria for quantitative analysis. The success rate of non-surgical root canal retreatment was 71% (95% CI: 66%-76%) with strict criteria and 87% (79% - 93%) with loose criteria for 1-3 years of follow-up, and 77% (66% - 86%) with strict criteria for a 4-5 years of follow-up. Endodontically retreated teeth with periapical lesions had a lower success rate under strict criteria. The tooth type, dental arch, initial periapical index (PAI) score, and the number of visits also affected the treatment success rate under strict criteria. For the loose criteria, teeth with larger periapical lesions and higher initial PAI scores had a lower success rate.

CONCLUSIONS

According to the present systematic review and meta-analysis, non-surgical root canal retreatment results in favourable outcomes. The presence of a periapical radiolucency, periapical lesions >5mm, a higher initial PAI score, multiple-visit retreatments, and mandibular and molar teeth resulted in a lower success rate.

CLINICAL SIGNIFICANCE

Non-surgical root canal retreatment filled with gutta-percha techniques is a relatively predictable procedure with a high success rate. Several variables can affect retreatment success, mainly the presence and size of a periapical lesion and the type of tooth.

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.

Effect of cleaning materials on microtensile bond strength of resin composite to primary dentin contaminated with root canal sealers

BACKGROUND

There have been no studies on the bond strength of adhesives with dentin surfaces contaminated with root canal sealers in primary teeth without underlying permanent teeth germs. This study investigated the cleaning materials used for primary tooth dentin contaminated with root canal sealers. The aim was to increase the success rate of root canal treatment in pedodontics clinics and retain the teeth for longer.

METHODS

The occlusal enamel layer was removed, followed by the application of root canal sealers (AH Plus or MTA Fillapex) to the dentin and cleaning using different irrigation solutions (saline, NaOCl, and ethanol). The specimens were restored using a self-etch adhesive and composite. Sticks with a thickness of approximately 1 mm were obtained from each sample, and the bond strengths were measured using a microtensile testing device. The interfacial morphology of the bonded space was evaluated using scanning electron microscopy.

RESULTS

The control and AH Plus saline groups had the highest bond strengths. The groups cleaned using ethanol had the lowest bond strengths (p < 0.01).

CONCLUSION

Cleaning the dentin with saline-soaked cotton pellets provided the best bond strengths. Therefore, saline is the most effective material for removing both epoxy resin- and calcium silicate-based root canal sealers from the access cavity.

Outcome of non-surgical root canal retreatment procedures obturated with warm gutta-percha techniques: A longitudinal clinical study

OBJECTIVE

To evaluate the success rate of non-surgical root canal retreatment at the 2- to 3-year follow-up and identify the possible prognostic factors.

METHODS

Patients who underwent root canal retreatment at a university dental clinic were contacted for clinical and radiographic follow-up. The retreatment outcomes in these cases were based on clinical signs, symptoms, and radiographic criteria. Inter- and intra-examiner concordance were calculated using Cohen's kappa coefficient. The retreatment outcome was dichotomized into success or failure according to strict and loose criteria. The radiographic success criteria consisted of complete resolution or absence of a periapical lesion (strict criteria) or a reduction in the size of an existing periapical lesion at recall (loose criteria). χ² tests were used to evaluate possible variables associated with retreatment outcomes (age, sex, tooth type, location, contact points, periapical status, quality of previous and final root canal filling, previous and final restoration, number of visits, and complications).

RESULTS

Overall, 129 teeth (113 patients) were included in the final evaluation. The success rate was 80.6% under strict criteria and 93% under loose criteria. Molars, teeth with an initially higher periapical index (PAI) score, and teeth with > 5 mm periapical radiolucency had a lower success rate according to the strict criteria model (p < 0.05). When the loose success criteria were used, teeth with larger (> 5 mm) periapical lesions and those that had been perforated during retreatment showed a lower success rate (p < 0.05).

CONCLUSIONS

The present study demonstrated that non-surgical root canal retreatment is a highly successful procedure after an observation period of 2-3 years. Treatment success is primarily affected by the presence of periapical lesions.

Radiographic Evaluation of the Gap between Cemented Post and Remaining Gutta-Percha in Endodontically Treated Teeth Performed by Undergraduate Students: A Retrospective Cross-Sectional Study

The coronal seal in root canal-treated teeth may be compromised depending on the accuracy of post space preparation and post cementation along with remaining gutta-percha. Root canal treatment can be compromised by endotoxins released by the coronal bacteria as a result of microleakage. The study was conducted by undergraduate students to measure the gap between the cemented post and residual gutta-percha. In total, 217 endodontically treated teeth were evaluated with intraoral peri-apical radiographs. Based on the intraoral periapical radiographic examination in the CS-R4 program, Group I had no gap, Group II had a gap of >0 to 2 mm, and Group III had a gap of more than 2 mm between the end of the cemented post and the remaining gutta-percha. In total, 40% (n = 87) of the teeth had no gap, 59% (127) had a gap of >0 to 2 mm, and 1% (n = 3) had a gap of more than 2 mm between the cemented post end and remaining gutta. Chi square test revealed a significant difference in the gap between the post and remaining gutta-percha between males and females students (p < 0.001). In terms of the gap between the cemented post end and the residual gutta-percha, the root canal treated teeth with post and core by undergraduates were clinically acceptable.

Apical periodontitis and associated factors in a rural population of southern Brazil: a multilevel analysis

OBJECTIVES

This study aims to evaluate the association between apical periodontitis (AP) and sociodemographic/clinical factors in a probability sample of individuals living in a rural area of southern Brazilian.

MATERIALS AND METHODS

A cross-sectional study was conducted involving 584 non-edentulous adult individuals who had undergone a full-mouth radiographic survey. Periapical status was analysed using the periapical index (PAI). Endodontic status was evaluated considering the occurrence of voids in the filling material and the root filling length. Crown status was classified based on the presence of caries, restorations, and prosthetic crowns. Sociodemographic variables, frequency of dental care, and periodontal disease were also registered. The data were analysed using hierarchical multilevel Poisson regression analysis. The multilevel structure was composed of three models: sociodemographic variables, clinical variables, and clinical variables adjusted by sociodemographic variables (α = 5%).

RESULTS

The prevalence of AP in the sample was 60.45%. AP was significantly associated with age, skin colour, schooling, periodontal disease, and frequency of dental care (P < 0.005). Among the 10,396 teeth evaluated, 868 (8.35%) had AP, which was significantly associated with tooth group, dental arch, crown status, and endodontic treatment (P < 0.005).

CONCLUSIONS

The prevalence of AP was high in the population studied. An older age, black/brown skin colour, low level of schooling, infrequent dental care, severe periodontal disease, mandibular teeth, posterior teeth, inadequate crown status, and having undergone endodontic treatment were significantly associated with the outcome. Clinical relevance This study about a rural probability sample reinforces that AP is still a recurrent oral health problem.

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.

Periapical status transitions in teeth with posts versus without posts: a retrospective longitudinal radiographic study

OBJECTIVES

The aim of this study was to compare periapical status transitions in teeth after post placement compared with other post-endodontic treatments in root-filled teeth.

MATERIAL AND METHODS

This retrospective longitudinal radiographic study included radiographs of 284 patients with root filled and restored teeth with composite fillings (Endo-fill group, n = 100), crown or fixed prosthesis (Endo-crown group, n = 82) or post and core restorations (Endo-post group, n = 102). All post and core restorations were made of gold alloy. The radiographs taken at the end of endodontic treatment, at the end of post-endodontic treatment and at least 8 months after post-endodontic treatment were evaluated. Post-operative periapical status was assessed according to the periapical index (PAI) and all teeth included in the study had no apical periodontitis preoperatively. Multi-state Markov analysis was used to assess periapical status transitions among the treatment groups.

RESULTS

Of 284 root-filled teeth without apical periodontitis at baseline, 7.7% developed clear apical pathology within a minimum of 8 months observational period. In the Endo-post group 11 (10.78%) teeth transited from Healthy (PAI 1) to Disease (PAI 2-4) state compared with eight (9.75%) in the Endo-crown group and four (4%) in the Endo-fill group. The transition probabilities from Healthy (PAI 1) to Mild diseased (PAI 2) were 17.5% in the Endo-post group, 13.1% in the Endo-crown group and 5.3% in the Endo-fill group. Multivariate analysis showed that teeth in the Endo-fill group had 60% lower hazard to transit from Healthy (PAI 1) to Mild diseased (PAI 2) state [HR 0.40; 95% CI 0.12, 0.94]. A period exceeding 8 months between the end of the endodontic treatment and prosthetic treatment significantly increased the hazard of disease progression by three times compared with a period of ≤8 months [HR 3.16; 95% CI 1.06, 9.42].

CONCLUSIONS

Teeth without radiographic lesions at baseline and restored with posts had higher hazard to transit from healthy to diseased periapical status compared with teeth restored with composite restorations. Controlled clinical trials with longer follow-up periods are needed to validate these findings.

The efficacy of different sealer removal protocols on the microtensile bond strength of adhesives to a bioceramic sealer-contaminated dentin

Background

The optimal bonding of adhesives to dentin requires the sealer to be completely removed from the dentinal walls.

Aim

This study compared the efficacy of different sealer removal protocols on the microtensile bond strengths (MTBS) of single-step adhesives to a calcium silicate-based bioceramic root canal sealer-contaminated dentin.

Materials and Methods

Standardized box-shaped Class I cavities were prepared in human lower third molars (N = 50). All cavities were contaminated with a bioceramic root canal sealer (Endosequence BC Sealer, Brasseler, Savannah, USA), except the control group (G1) cavities. For the experimental groups, contaminated dentin surfaces were wiped with a dry cotton pellet (G2), wiped with a cotton pellet saturated with water (G3), rinsed with the air/water spray (G4), and passively applied aqueous ultrasonic energy with an ultrasonic scaler (G5) before the restoration procedure. All the cavity surface was restored with a one-bottle universal adhesive and composite resin. All the specimens were subjected to both thermocycling (2,500 thermal cycles from 5 to 55°C, with a 30-s dwelling time and a 10-s transfer time) and mechanical loading (50 N load for 100,000 cycles). The restored specimens were sectioned into resin-dentin beams for MTBS evaluation. Additional specimens were prepared for the scanning electron microscopy (SEM) to examine the dentin-adhesive interface (n = 10).

Results

No significant difference was found between the mean bond strengths of the groups. In SEM examination, no residual sealer was found in any group.

Conclusion

Calcium silicate-based bioceramic sealer was removed from the dentin surface with all removal protocols when evaluated with MTBS after the thermal and mechanical cycle tests.

Including dental professionals in the multidisciplinary treatment team of head and neck cancer patients improves long-term oral health status

Objective

To assess in a cross-sectional study the impact of including dental professionals in the multidisciplinary treatment team of head and neck squamous cell carcinoma (HNSCC) patients on the long-term oral health status.

Materials and methods

Oral health status, dental care behaviours, and oral health–related quality of life were assessed based on a clinical and radiographic examination, interview, and medical records in patients treated for HNSCC ≥ 6 months ago. This patient group (‘cohort 2’) was treated in a multidisciplinary treatment team including dental professionals and compared to a group of HNSCC patients previously treated at the same university, but without dental professionals included in the multidisciplinary treatment team (‘cohort 1’).

Results

Cohort 2 consisted of 34 patients, who had received a dental check-up and if necessary, treatment by dental professionals prior to the initiation of cancer treatment. This cohort showed significantly improved oral hygiene habits and a better periodontal health status compared to cohort 1. However, cohort 2 still presented high demand for treatment due to active carious lesions; only a few, statistically insignificant improvements were detected compared to cohort 1.

Conclusion

Including dental professionals in the multidisciplinary treatment team of HNSCC patients has a positive impact on patient oral health status—primarily in terms of periodontal disease—6 months and longer after finishing cancer therapy.

Clinical relevance

A team-based approach including dental professionals specialised in head and neck cancer improves oral health status.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-04276-x.

A retrospective three-dimensional assessment of the prevalence of apical periodontitis and quality of root canal treatment in Mid-West Indian population

Introduction

This study aims to report a retrospective observation of the prevalence of apical periodontitis (AP) and quality of root canal treatment in cone-beam computed tomography (CBCT) scans among the Mid-West Indian population.

Materials and Methods

A total of 1229 CBCT scans were obtained across different CBCT centers in western India. After the exclusion criteria, those that were included were divided into broadly two groups - those that were filled and those that were unfilled. Various parameters were taken into account such as AP, length of the root canal filled, and coronal filling.

Results

There were a significantly higher percentage of nonfilled canals. Poor filling quality, inadequate coronal restoration, and also missed extra canal were significantly associated with AP. Both males and females showed higher presence of AP in the nonfilled teeth than filled ones (X2 - Chi square value M = 612.156, P < 0.00001, X² F = 1032.9092, P < 0.00001).

Conclusion

(1) The inadequacy of the filling of the root length was a contributory factor to the higher prevalence of AP among the study population. (2) The density of the filling and the quality of the coronal filling also significantly affected the successful outcome of the root canal treatment.

Is Coronal Restoration a Predictor of Posttreatment Apical Periodontitis?

Objectives  To investigate the posttreatment apical periodontitis (AP) in endodontically treated teeth through a multivariate approach and to analyze the relative importance of quality and type of coronal restoration as predictors of periapical disease.

Materials and Methods  The present study sample was drawn within 2-year period from the 1,072 consecutive patients older than 18 years, first time attending the Dental Clinic of the Clinical Hospital Center Rijeka, Croatia. A total of 1,350 endodontically treated teeth were included in the study. For each tooth, the periapical status, root filling quality, intracanal post, separated file presence, marginal bone loss, and quality and type of coronal restoration were recorded.

Statistical Analysis  Chi-square tests were used to analyze the variations in the periapical status, quality of root canal filling, and quality of coronal restoration in different tooth types. The effect of explanatory variables on periapical status was explored using univariate and multivariate logistic regression models. The outcome variable was set as the presence versus absence of AP in the tooth.

Results  Multivariate logistic regression analysis revealed statistically significant associations and increased risk for AP presence in molars (odds ratio [OR] = 2.15; p  < 0.001), teeth positioned in mandible (OR = 1.49; p  = 0.007), teeth with short length of root filling (OR = 4.08; p  < 0.001), overfilled teeth (OR = 2.99; p  = 0.001), and teeth with inadequate density of root filling (OR = 4.14; p  < 0.001). Considering variables related to coronal restoration, neither coronal restoration type nor quality was found to be predictive for posttreatment AP. Merely, the presence of intracanal post significantly increased the odds of AP presence (OR = 1.57; p  = 0.009).

Conclusion  The results of the present study did not indicate that type or quality of coronal restoration may be predictors of posttreatment AP. Periapical disease was significantly associated with molars, mandibular teeth, substandard quality of root fillings, and intracanal post presence.

Influence of remaining axial walls on of root filled teeth restored with a single crown and adhesively bonded fibre post: A systematic review and meta-analysis

OBJECTIVES

To synthesise evidence on structural failures and prevalence of post-treatment endodontic disease (PTD) in anterior and posterior root filled teeth with a single crown and adhesively bonded fibre post with regards to the number of axial walls.

DATA

An electronic search was performed, no language constraints or restriction on the year of publication were applied.

SOURCES

PubMed, Medline, Cochrane and Scopus on 13th of July 2021.

STUDY SELECTION

Clinical studies that reported the remaining number of axial walls for permanent anterior and posterior root filled teeth (RFT) restored with single crowns and adhesively bonded fibre posts with a minimum of 1 year follow-up were included. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines [1] were used. The number of axial walls and the success/failures were analysed as follows: fibre post and/or core decementation, post and/or core fracture and post treatment endodontic disease, and root fracture.

CONCLUSIONS

A total of 811 studies were identified with 5 meeting the inclusion criteria. The two randomized controlled trials included had 'some concerns' as determined by the Cochrane risk-of-bias 2 tool while the Newcastle-Ottawa scale found low risk of bias for the remaining three studies. The random effects model for subgroup meta-analysis revealed failures for posterior RFT increased with decreasing numbers of remaining walls. Failures for 0 remaining walls were 23% (95% CI = 10% - 36%) and for one remaining wall 15% (CI: 3% -26%), irrespective of follow-up times. Fibre post debonding and PTD increased with decreasing numbers of walls. Relative & catastrophic failure of posterior teeth restored with a fibre post and single crown after root canal treatment increased with decreasing numbers of remaining axial walls.

CLINICAL SIGNIFICANCE

This synthesis is unique as it minimizes the presence of confounding factors by reviewing evidence of failures and post-treatment endodontic disease associated with teeth restored with single crowns. Therefore, it provides valuable predictive evidence of potential coronal restoration catastrophes and post-treatment endodontic disease associated with root filled teeth.

Restorative Treatment Patterns After Root Canal Obturation in Public Hospitals in Riyadh

AIM

This study aims to describe the pattern of coronal restoration use among different dental specialties after root canal obturation in two governmental hospitals in Riyadh.

MATERIALS AND METHODS

Electronic dental records at King Abdul-Aziz Medical City and University Dental Hospital were reviewed. Teeth that underwent initial root canal treatment on a permanent tooth for obturation using gutta-percha between April 2019 and June 2019 were included. The collected data included the type of material used for coronal restoration after RCT, immediate post-space preparation, cotton pellet placement, the clinical title and specialty of the treating physician, and the center where treatment was performed. Excel was used for data collection. IBM SPSS was used for descriptive and interferential analyses.

RESULTS

A total of 763 patients were included in the study, in which the double seal technique was used in 56% of the patients, followed by Cavit, which was used in approximately 17% of the patients. Post space was prepared immediately after root canal treatment in 49 patients, and only 17 teeth received the final post, whereas post space was temporized for the rest of the prepared teeth and received the final post at the following visits. Significant relations were found between the type of material used and the clinical title of the treating physician and between the material of choice and the specialty of the dentist. The double seal was the technique of choice among endodontists and restorative dentists, whereas advanced general dentists frequently used Cavit. The least used materials were IRM, amalgam, and Ketac Silver.

CONCLUSION

The double seal technique was found to be the most commonly used method to achieve a coronal seal, followed by Cavit. Other materials used after RCT, in sequential order based on the frequency of use, were GIC, temporary crowns, resin composite, RMGIC, prefabricated post with composite buildup, IRM, amalgam, and Ketac Silver.

Assessment of bacterial and dye penetration through post/crown interim restorations while under simulated masticatory load

The aim was to compare two temporary cements to determine which resisted bacterial and dye penetration under temporary posts/cores/crowns subjected to simulated masticatory function. Forty-six single canal human tooth roots were prepared for posts/crowns. A cotton pellet and Cavit were placed in each post space. Temporary posts/cores/crowns were cemented with Intermediate Restorative Material (IRM) (n = 23) or Tempocem (n = 23). Specimens were sterilised, then immersed in a mixture of Streptococcus gordonii and India ink, and subjected to 4 weeks simulated mastication. Dye penetration was assessed by visually inspecting the cotton pellets. Bacterial penetration was determined by placing the pellets into sterile broth and by plating them onto agar plates to confirm S. gordonii growth. There was no statistically significant difference between the cements and the dependent variables of bacterial and dye penetration. Hence, both cements are good options to cement temporary posts/cores/crowns during endodontic treatment of anterior teeth.

Effect of prosthetic restorations and root canal fillings on periapical health in a selected patient group

Aims To examine the effect of the quality of root canal fillings and prosthetic restorations on the frequency of apical periodontitis (AP).Methodology A total of 200 radiographs of 1,098 teeth with indirect restorations were selected. Each case was documented by age, sex, tooth location, tooth type, restoration type and presence of root canal treatment (RCT). Teeth were categorised as healthy or diseased considering periapical health. The quality of RCT and prosthetic restorations was categorised by radiographic and clinical examinations. Data were analysed using chi-squared test and logistic regression.Results Inadequate prosthetic restorations were found to be less healthy than the adequate ones. Statistical significance was found in teeth with RCT, which had a higher rate of AP (15.8%). Root-filled teeth categorised as inadequately treated (24.1%) were significantly unhealthier than the adequately root-filled teeth. Teeth with inadequate prosthetic restorations and RCT had an increase in AP risk of 6.41 and 20.74 times, respectively (p <0.05).Conclusions Results showed that AP risk was increased by both inadequate RCT and prosthetic restorations. Quality of RCT significantly affected periapical health more than the quality of prosthetic restorations. Not only radiographic but also clinical examination of restorations is required for successful evaluation.

Presence of voids after three obturation techniques in band-shaped isthmuses: a micro-computed tomography study

Background

The objective of the present micro-computed tomography (micro-CT) study was to assess the presence of voids in band-shaped isthmuses obturated using three different filling techniques.

Methods

Twenty-four artificial molar teeth with a band-shaped isthmus were allocated to three groups (n = 8) for obturation, according to the filling technique: single-cone (SC), continuous wave of condensation (CWC) or lateral condensation (LC). Obturation was performed with gutta-percha (GP) cones and iRoot SP (Innovative Bioceramix, Vancouver, Canada). Post-filling micro-CT scanning was performed. The percentage of filling materials and void volumes were calculated in the isthmus areas and data were analyzed using one-way ANOVA and Tukey tests.

Results

The mean percentage of void volumes and corresponding filling percentages in the isthmus areas after obturation in the SC groups was 22.98 % ± 1.19 %, 77.02 % ± 1.19 %; in the CWC groups 10.46 % ± 2.28 %, 89.54 % ± 2.28 %; and in the LC groups was 13.14 % ± 1.85 %, 86.86 % ± 1.85 %, respectively.

Conclusions

In band-shaped isthmus area, the obturation quality of CWC was superior to SC and LC techniques.

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%.

Coronal Restoration as a Predictor of Periapical Disease in Non-Endodontically Treated Teeth

Objectives

To compare the frequency of apical periodontitis (AP) in non-endodontically treated teeth restored with full coverage crowns, amalgam and resin composite fillings, and to disclose the association of type and quality of coronal restoration with periapical disease.

Material and Methods

The cross-sectional study involved 597 subjects who attended the Dental Clinic of the Clinical Hospital Centre, Rijeka, Croatia for the first time. Data were collected by means of a clinical and radiological survey. The following data were recorded for all permanently restored non-endodontically treated teeth: the type, the quality of coronal restoration according to clinical and radiographic criteria for marginal integrity as well as the recurrent caries presence, periapical status and marginal bone loss. Chi-square tests were used to analyze the difference in periapical status regarding the type and the quality of restoration. The multivariate logistic regression analysis was used to assess the effect of explanatory tooth-specific variables on periapical status.

Results

There was no significant difference in the proportion of AP with regards to the type and material of adequate quality coronal restorations (χ²=5.000, P=0.082). The regression analysis revealed significant positive associations with outcome variable (AP) for crowns (OR=3.39; P<0.001), recurrent caries (OR=4.67; P<0.001) and premolar teeth (OR=1.73; P=0.002).

Conclusion

If the quality of restorations is adequate, there is no difference in the periapical status of non-endodontically treated teeth regarding the type and material of coronal restoration.

The restoration of root filled teeth: a review of the clinical literature

Clinicians often face dilemmas regarding the most appropriate way to restore a tooth following root canal treatment. Whilst there is established consensus on the importance of the ferrule effect on the predictable restoration of root filled teeth, other factors, such as residual tooth volume, tooth location, number of proximal contacts, timing of the definitive restoration and the presence of cracks, have been reported to influence restoration and tooth survival. The continued evolution of dental materials and techniques, combined with a trend towards more conservative endodontic-restorative procedures, prompts re-evaluation of the scientific literature. The aim of this literature review was to provide an updated overview of the existing clinical literature relating to the restoration of root filled teeth. An electronic literature search of the PubMed, Ovid (via EMBASE) and MEDLINE (via EMBASE) databases up to July 2020 was performed to identify articles that related the survival of root filled teeth and/or restoration type. The following and other terms were searched: restoration, crown, onlay, root canal, root filled, post, clinical, survival, success. Wherever possible, only clinical studies were selected for the literature review. Full texts of the identified articles were independently screened by two reviewers according to pre-defined criteria. This review identifies the main clinical factors influencing the survival of teeth and restorations following root canal treatment in vivo and discusses the data related to specific restoration type on clinical survival.

An In Vitro Comparative Evaluation of Apical Leakage Using Different Root Canal Sealers

Background

Successful endodontic therapy requires a fluid-tight apical seal. The aim of this in vitro study was to evaluate and compare the apical sealing ability of 3 root canal sealers: Apexit Plus, AH Plus, and Resilon/Epiphany sealers.

Material/Methods

Samples of 152 single-rooted teeth were divided into 2 test groups, and each group was divided into 3 subgroups based on the preparation and obturation technique. After preparation with the step-back technique, the first group of root canals were obturated with lateral gutta-percha compaction in combination with AH Plus sealer or Apexit Plus or with the Resilon/Epiphany system alone. In the second group, preparation was done with the crown-down technique and root canals were then obturated with Thermafil obturator in combination with AH Plus or Apexit Plus or with Resilon/Epiphany sealer alone. Apical leakage was determined using a dye leakage test observed with a stereomicroscope. The degree of dye leakage was assessed using the t test to comparing the arithmetic averages of the groups.

Results

In the groups prepared with the step-back technique, the average dye leakage was lower in samples obturated with Resilon/Epiphany, than in those filled with AH Plus/lateral gutta-percha compaction or Apexit Plus/lateral gutta-percha compaction. In groups prepared with the crown-down technique and obturated with the Resilon/Epiphany system, the average dye leakage was lower than in those filled with AH Plus/Thermafil obturation and those filled with Apexit Plus/Thermafil obturation.

Conclusions

Although all preparation and obturation techniques showed dye penetration, the crown-down technique paired with the Resilon/Epiphany system showed the least leakage.

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.

Influence of the coronal restoration on the outcome of endodontically treated teeth

Objective: The tooth weakens due to removal of hard tissue during an endodontic procedure. Many dentists find it difficult to choose between different coronal restorations after root canal treatment (RCT). Studies show that the coronal restoration may affect the endodontic prognosis. This student-based study had three aims. (1) Examine the choice of coronal restoration of endodontically treated teeth at a Scandinavian dental school, (2) examine the survival of these restorations and (3) evaluate the influence of the coronal restoration on the outcome of the RCT. Material and methods: Radiographic and clinical examination was performed on 127 posterior teeth. The quality of the root canal treatment and the periapical status (PAI-index) were evaluated. Results: 43.8% of the teeth were restored with an indirect coronal restoration and 47.2% with a direct coronal restoration. The period from finished root canal treatment until placement of a permanent coronal restoration was significantly longer for an indirect restoration than a direct restoration. The teeth treated with a PAI score of 1 and 2 following pulpectomy, necrotic pulp treatment and endodontic retreatment was 93.8%, 82.6% and 69.4%, respectively.Conclusion: There was no significant association between choice of coronal restoration and PAI-score.

The Effect of Smoking Habit on Apical Status of Adequate Endodontically Treated Teeth with and Without Periodontal Involvement

Background

The possible connection between apical periodontitis (AP), periodontal disease (PD) and the bad habit of smoking is among the most interesting aspects faced by the dental scientific community. The aim of this study was to pinpoint the effect of smoking on the status of the apical region, in properly root-filled teeth with and without periodontal involvement of Iraqi males.

Materials and methods

Total number of 75 patients were chosen, divided into 3 groups of 25’s, teeth were subdivided into 6 subgroups (G-a: Light smokers without Periodontal involvement, G-b: Heavy smokers without Periodontal involvement, G-c: Non-smokers without Periodontal involvement, G-d: Light smokers with Periodontal involvement, G-e: Heavy smokers with Periodontal involvement, G-f: Non-smokers with Periodontal involvement), examination involved: clinical periodontal parameters, coronal restoration fitness. Panoramic and periapical radiographs were used to judge the quality of periodontal tissue in the apical region (AP) of root canal treated teeth.

Results

Among all the examined teeth (1859), only (89) were found with fitted both coronal and endodontic restorations. Rates of AP were: (G-a: 11.1%, G-b: 25%, G-c: 0%, G-d: 18.8%, G-e: 35.7%, G-f: 4.8%). Statistically, in related to the AP, there was a highly significant difference between heavy smokers’ groups (G-b, G-e). Moreover, heavy smokers with PD (G-e) showed a significant difference with light smokers without PD (G-a) and non-smokers without PD (G-c), also, there was a significant difference between heavy smokers without PD (G-b) and non-smokers with PD (G-f). While, there was a non-significant difference relationship between non–smokers’ groups (G-c, G-f), and light smokers’ groups (G-a, G-d).

Conclusion

There is a noticeable negative effect of smoking on the severity and prognosis of AP and this negative effect worsens when it is accompanied by lateral periodontitis.

The effect of an intraorifice barrier and base under coronal restorations on the healing of apical periodontitis: a randomized controlled trial

AIM

To evaluate the effect of intraorifice barriers and bases on the healing of apical periodontitis following root canal treatment in mandibular molars.

METHODOLOGY

A total of 120 permanent mandibular molars with necrotic pulps and periapical radiolucencies (PAI score ≥ 3) were recruited. Root canal treatment was performed in all teeth using a standard protocol, following which they were randomly allocated to one of the three treatment groups: intraorifice barrier group: coronal 3-mm gutta-percha was removed and replaced with glass-ionomer cement (GIC) barrier. The floor of the pulp chamber was then sealed with 2-mm-thick GIC base followed by final composite resin restoration; base group: received 2-mm-thick GIC base before placement of composite resin restoration; and control group: had pulp chamber entirely filled with composite resin only. Follow-up was done at 3, 6, 9 and 12 months. Combination of clinical and radiographic parameters were used to assess treatment outcome. The data were analysed using Kruskal-Wallis, chi-square and Wilcoxon signed-rank tests and logistic regression analysis.

RESULTS

At the end of 12 months, the base group had the most favourable healing (97.1%), whilst the control group had the least favourable healing (83.8%). The intraorifice barrier group had healing of 92.1%. However, there was no significant difference in healing between groups at the end of the follow-up period (P > 0.05). Additional subgroup analysis revealed a nonsignificant effect of periodontal status and root filling level on periapical healing.

CONCLUSION

The use of an additional barrier under permanent restorations did not significantly improve the outcome of primary root canal treatment in posterior teeth after 12 months. However, its influence in the long term requires further evaluation.

Cone-beam computed tomography in the assessment of periapical lesions in endodontically treated teeth

Objective:

This study aimed to evaluate the relationship between the quality of the coronal restoration and the root canal filling on the periapical status of endodontically treated teeth using CBCT.

Materials and Methods:

CBCT data were obtained from the records of patients who deny any dental treatment in the 2 years prior to the CBCT examination. CBCT images (90 kVp and 7 mA, exposure time of 23 s, and a voxel size of 0.2 mm, with a field of view of 13 cm × 13 cm) of 1011 endodontically treated teeth were observed. A score was given to the quality of the root filling and the quality of the coronal restoration.

Statistical Analysis Used:

Data were statistically analyzed to correlate the periapical status with gender, dental group. and quality of endodontic treatment and restoration (Chi-square test with a significance level of P < 0.001).

Results:

Absence of periapical periodontitis was found in 54.9% of the cases. The periapical outcome was not related to gender or dental group (P > 0.05). A statistically significant factor (Chi-square test, P < 0.0001) resulted when different qualities of sealing were compared.

Conclusions:

CBCT showed that high-quality root canal treatments followed by an adequate coronal sealing restoration avoid the presence of periapical periodontitis in time.

The "Plan" phase of a Deming cycle: Measurement of quality and outcome of root canal treatments in a university hospital

INTRODUCTION

In many countries, dental students are taught in private or university hospitals where they treat patients under the supervision of teachers. Assessing the quality of root canal treatments (RCT) would provide information about the quality of care patients receive when treated by students.

METHODS

This study describes the six-step "Plan" phase of a Plan-Do-Check-Act (PDCA) cycle that identifies and analyses clinical practices in endodontics in a university dental hospital service.

RESULTS

Step 3 reported that the proportion of RCTs of adequate quality reached 57.1% and this proportion was significantly decreased when specific indicators for treatment difficulties were present. The proportion of successful RCTs after 1 year was 65.6%, and its variation was influenced by the preoperative periapical status rather than the quality of RCTs. The consensual meeting in Step 6 proposed to introduce three new procedures for the further Do, Check and Act phases of the PDCA cycle.

CONCLUSION

This study encourages systematic evaluation of RCTs and provides the first step of the methodology that can be reproduced in private and hospital practices where students are asked to treat patients.

Potencial antimicrobiano de diferentes retentores intrarradiculares frente a Enterococcus faecalis: uma avaliação in vitro

Resumo Introdução O tratamento endodôntico tem como objetivo erradicar microrganismos bacterianos e fúngicos do canal radicular, ou pelo menos possibilitar sua redução para níveis compatíveis com a saúde do tecido perirradicular, uma vez que, após o tratamento endodôntico, colônias de microrganismos residuais podem estar presentes nos túbulos dentinários e no cemento. Objetivo Avaliar o potencial antimicrobiano de diferentes tipos de retentores intrarradicularess em dentes bovinos. Material e método 50 dentes unirradiculares após tratamento endodôntico concluído foram desobturados, bem como tiveram seus condutos preparados para a cimentação dos retentores intrarradiculares. Posteriormente, os dentes foram contaminados por Enterococcus faecalis por meio da montagem de um dispositivo, o qual permitiu a infiltração bacteriana. Os dados resultantes da contagem das Unidades Formadoras de Colônia foram analisados utilizando o teste de ANOVA one-way, seguido pela análise de comparações múltiplas de Tukey. Resultado Decorrido o período de 14 dias, o grupo que apresentou a maior infiltração bacteriana foi o grupo-controle, o qual não continha nenhum tipo de retentor intrarradicular, seguido do G1-FV (grupo de continha retentor radicular de fibra de vidro) e G2-FC (grupo de que continha retentores radiculares de fibra de carbono). O menor grau de recuperação bacteriana foi encontrado nos grupos G3-Ni-Cr e G4-Cu-Al, os quais continham retentores intrarradiculares metálicos formados por ligas de níquel-cromo e cobre-alumínio, respectivamente. Conclusão Os retentores aqui avaliados apresentam diferentes efeitos antimicrobianos. Assim, a utilização de um pino com melhores resultados antimicrobianos favorece maiores chances de sucesso nos tratamentos reabilitadores.

Unprepared root canal surface areas: causes, clinical implications, and therapeutic strategies

Chemomechanical preparation is intended to clean, disinfect, and shape the root canal. This step is of utmost importance during treatment of infected teeth with apical periodontitis, because treatment outcome depends on how effectively the clinician eliminates bacteria, their products, and necrotic tissue that would serve as substrate for bacterial regrowth. Nonetheless, curvatures and complex internal anatomical variations of the root canal system can pose a high degree of difficulty in reaching these goals. In infected teeth, bacteria may persist not only in difficult-to-reach areas such as isthmuses, ramifications, dentinal tubules, and recesses from C-shaped or oval/flattened canals, but also in areas of the main canal wall that remain untouched by instruments. If bacteria withstand chemomechanical procedures, there is an augmented risk for post-treatment apical periodontitis. This article discloses the reasons why some areas remain unprepared by instruments and discusses strategies to circumvent this issue and enhance infection control during endodontic treatment/retreatment of teeth with apical periodontitis.

Post-treatment apical periodontitis related to the technical quality of root fillings and restorations in Thai population

The aim of this study was to investigate the post-treatment apical periodontitis in endodontically treated teeth related to the technical quality of root fillings and restorations in Thai population. Full-mouth periapical radiographs from Thai patients attending the Faculty of Dentistry, Mahidol University, Thailand were examined. The periapical status, quality of root fillings and coronal restorations, existence of intraradicular post and its relationship to the root fillings were evaluated. Among 1586 patients, 37.4% presented endodontically treated teeth. The total number of endodontically treated teeth was 1511, and 35% presented apical periodontitis. Combined data for root filling and coronal restoration qualities revealed significantly better outcome in teeth with adequate qualities of both parameters than the other combinations (P < 0.001). The prevalence of post-treatment apical periodontitis among Thai population was relatively high and significantly associated with substandard technical quality of root fillings and restorations.

Zinc oxide eugenol paste jeopardises the adhesive bonding to primary dentine

AIM

This was to evaluate the influence of root canal filling pastes on microshear bond strength (µSBS) of an adhesive system to primary dentine.

METHODS

Human (32) primary molars were randomly assigned into four experimental groups (n = 8): zinc oxide eugenol paste (ZOE); iodoform paste (Guedes-Pinto paste); calcium hydroxide paste thickened with zinc oxide; and no filling paste (control). Flat dentine surfaces were covered with a 1 mm-thick layer of the pastes for 15 min at 37 °C. The pastes were mechanically removed from dentine surfaces, followed by rinsing and drying. After adhesive application (Adper Single Bond 2, 3M ESPE), starch tubes were placed over pre-treated dentine and filled with composite resin (Z250, 3M ESPE). The µSBS test was performed after 24 h of water storage at 37 °C. The failure mode was evaluated using a stereomicroscope. The µSBS values (MPa) were analysed with one-way ANOVA and Tukey post-hoc tests (α = 0.05).

RESULTS

The lowest µSBS values were achieved when ZOE was used. No difference was found among other filling pastes compared with control group. All specimens showed adhesive/mixed failures.

CONCLUSIONS

Zinc oxide eugenol paste negatively influenced the bond strength of adhesive systems to primary dentine. Iodoform-based Guedes-Pinto paste and calcium hydroxide paste thickened with zinc oxide did not influence the microshear bond strength values.

A comparative evaluation of shear bond strength of composite resin to pulp chamber dentin treated with sodium thiosulfate and proanthocyanidin: An in vitro study

Aim:

Based on the importance of coronal sealing right after endodontic treatment, this in vitro study aimed to evaluate the difference of shear bond strength to pulp chamber dentin treated with sodium thiosulfate and proanthocyanidin (PA).

Materials and Methods:

Fifteen extracted mandibular molar teeth were decoronated at the level of cementoenamel junction horizontally. The individual teeth were then sectioned mesiodistally to expose the pulp chamber dentin using a diamond disc. The specimens were randomly divided into three groups (n = 10). Group A: control group, treated with 5.25% sodium hypochlorite (NaOCl) for 30 min followed by a final rinse with 17% ethylenediaminetetraacetic acid (EDTA) solution for 3 min; Group B: after pretreatment with NaOCl and EDTA, it is further treated with 5% sodium thiosulfate (Na₂S₂O₃) for 10 min; and Group C: after pretreatment with NaOCl and EDTA, it is further treated with 6.5% PA for 10 min. After drying the specimens, a bonding agent namely One Coat Bond SL (SwissTEC, Coltene) was applied to the pulp chamber dentin followed by a composite restoration (SwissTEC, Coltene). Each specimen was then tested under a universal testing machine at the dentin/resin interface to determine the shear bond strength.

Results:

Both the groups in which 5% Na₂S₂O₃ and 6.5% PA were used for 10 min showed bond strength that was found to be statistically higher than the positive control (P < 0.05).

Conclusion:

The use of Na₂S₂O₃ and PA can significantly increase the bond strength of composite resin to NaOCl/EDTA-treated dentin, allowing adhesive restorations to be immediately applied after endodontic treatment.

Apical periodontitis in southern Estonian population: prevalence and associations with quality of root canal fillings and coronal restorations

Background

Apical periodontitis (AP) is an inflammatory disease around the apex of a tooth root. Reported prevalence of AP ranges from 27% to 83% while the data about most post-Soviet countries are still missing. Knowing the prevalence of AP within a certain population helps to plan the treatment need and evaluate the success of endodontic interventions. We aimed to collect data about prevalence and determining factors of AP for the first time in Estonia.

Methods

The cross-sectional study included 6552 patients (age 35.5±19.2 years). Radiographic examination was applied to investigate the prevalence of AP and quality of endodontic treatment.

Results

AP was diagnosed in 54.7% of subjects. Endodontically treated teeth were present in 58.2% of subjects. Periapical finding was present in 44.6% of endodontically treated and in 30.8% of untreated teeth.

Out of 181,495 teeth, 52.7% were intact. AP was diagnosed in 6.3% of teeth, 6.9% of teeth were endodontically treated.

Risk factors for AP included caries (OR = 2.30), male gender (OR = 1.44), too short (OR = 1.76) or too long root canal filling (OR = 2.51), root canal filling of low density (OR = 1.61) while not orthodontic appliance. Lower AP risk was associated with restoration of the tooth – filling (OR = 0.45), crown (OR = 0.34) and bridge (OR = 0.33).

Conclusions

AP is highly prevalent in Southern Estonian population. Most cases are associated with root canal-treated teeth. The overall quality of root canal fillings tends to be low, consistent with the mediocre outcome of treatment. Considerable efforts are required to improve the standards of endodontic treatment.

Electronic supplementary material

The online version of this article (10.1186/s12903-017-0429-7) contains supplementary material, which is available to authorized users.

Smear layer removal by different chemical solutions used with or without ultrasonic activation after post preparation

Objectives

This study evaluated smear layer removal by different chemical solutions used with or without ultrasonic activation after post preparation.

Materials and Methods

Forty-five extracted uniradicular human mandibular premolars with single canals were treated endodontically. The cervical and middle thirds of the fillings were then removed, and the specimens were divided into 9 groups: G1, saline solution (NaCl); G2, 2.5% sodium hypochlorite (NaOCl); G3, 2% chlorhexidine (CHX); G4, 11.5% polyacrylic acid (PAA); G5, 17% ethylenediaminetetraacetic acid (EDTA). For the groups 6, 7, 8, and 9, the same solutions used in the groups 2, 3, 4, and 5 were used, respectively, but activated with ultrasonic activation. Afterwards, the roots were analyzed by a score considering the images obtained from a scanning electron microscope.

Results

EDTA achieved the best performance compared with the other solutions evaluated regardless of the irrigation method (p < 0.05).

Conclusions

Ultrasonic activation did not significantly influence smear layer removal.

Comparison of the Percentage of Voids in the Canal Filling of a Calcium Silicate-Based Sealer and Gutta Percha Cones Using Two Obturation Techniques

This study evaluated the root-filling quality of a calcium silicate-based sealer and gutta percha (GP) cones by measuring the percentage of voids. Twenty artificial molar teeth were divided into two groups: one obturated using the single-cone (SC) technique, and the other using the continuous wave (CW) technique. Obturation was performed with GP cones and Endoseal MTA (mineral trioxide aggregate, Maruchi, Wonju, Korea). Obturated teeth were scanned using microcomputed tomography, and the percentage of void volume was calculated in the apical and coronal areas. A linear mixed model was used to determine the differences between the two techniques (p < 0.05). The percentage of voids between the filling materials and root canal walls was not significantly different between the two obturation methods (p > 0.05), except for the CW group, which demonstrated a significantly higher void volume in the coronal area of the distal canal (p < 0.05). The percentage of voids inside the filling material was significantly higher in the CW groups for all of the comparisons (p < 0.05), except in the apical area of the distal canal (p > 0.05). The voids between the filling material and canal wall in the apical area were not significantly different between the two techniques.

A Radiographic Study of the Association between Apical Periodontitis and Technical Quality of Intraradicular Posts and Root Canal Fillings: A Cross-sectional Study in Qassim Region, Saudi Arabia

OBJECTIVES

This study evaluates the association between the apical periodontitis (AP) and quality of intraradicular posts and the quality of root fillings assessed radiographically in Qassim region, Saudi Arabia.

MATERIALS AND METHODS

Digital periapical radiographs of 327 teeth with post-retained restoration were retrieved randomly from the Qassim University screening clinic's digital archives and evaluated. The quality of the intraradicular post and root filling was evaluated according to the optimum criteria. The presence of AP was assessed based on the periapical index scoring system. The relation between the post technical quality, the quality of root filling, and AP was determined. The data were analyzed using Chi-square test and logistic regression.

RESULTS

AP was found in 22% of the investigated teeth. Adequate root fillings were found in 69% of roots, and 14% of these cases were associated with AP. In roots with root filling classified as inadequate, 38% had AP with a statistically significant association between the root filling length and the presence of AP (P < 0.001). The most frequently used posts were prefabricated metallic posts (57%). Teeth restored with cast posts and prefabricated metallic posts exhibited AP with a frequency of 42.3% and 25.4%, respectively, and teeth with nonmetallic posts had significantly fewer cases of AP (12.0%) with a statistically significant association between the post type and the presence of AP (P = 0.016).

CONCLUSION

Both the quality of the root filling and the intraradicular post type were correlated significantly with the presence of AP. The technical quality of root fillings and intraradicular posts was adequate. Nevertheless, the use of threaded posts is still a common practice in this study population.