Factors that cause endodontic failures in general practices in Japan

Graphene as a promising material in orthodontics: A review

Graphene is an extraordinary material with unique mechanical, chemical, and thermal properties. Additionally, it boasts high surface area and antimicrobial properties, making it an attractive option for researchers exploring innovative materials for biomedical applications. Although there have been various studies on graphene applications in different biomedical fields, limited reviews have been conducted on its use in dentistry, and no reviews have focused on its application in the orthodontic field. This review aims to present a comprehensive overview of graphene-based materials, with an emphasis on their antibacterial mechanisms and the factors that influence these properties. Additionally, the review summarizes the dental applications of graphene, spotlighting the studies of its orthodontic application as they can be used to enhance the antibacterial and mechanical properties of orthodontic materials such as adhesives, archwires, and splints. Also, they can be utilized to enhance bone remodeling during orthodontic tooth movement. An electronic search was carried out in Scopus, PubMed, Science Direct, and Wiley Online Library digital database platforms using graphene and orthodontics as keywords. The search was restricted to English language publications without a time limit. This review highlights the need for further laboratory and clinical research using graphene-based materials to improve the properties of orthodontic materials to make them available for clinical use.

Elimination of E. faecalis with NaOCl versus chlorhexidine gluconate from primary molar root canal systems: an ex vivo model study

OBJECTIVES

This ex vivo human study aimed to evaluate the efficacy of NaOCl and chlorhexidine gluconate (CHG) irrigations in eliminating Enterococcus faecalis from the RCS of primary molars.

MATERIALS AND METHODS

Disinfected extracted primary molars were inoculated with E. faecalis for 24 h. Then, the RCS samples were then irrigated with either 2.5% NaOCl, 0.2% and 2% CHG, or sham saline. The samples were collected immediately after irrigation; and 24 h later, the bacterial viability and counts were measured using blood agar and qRT-PCR, respectively. Histological sections were used to measure E. faecalis penetration and viability in dentin tubules using fluorescence microscopy.

RESULTS

The recovery of viable E. faecalis after the irrigation of the primary molars showed more significant bactericidal effects of NaOCl and 0.2% and 2% CHG than of saline. Immediately after the irrigation, the NaOCl group showed the greatest reduction in E. faecalis; and 24 h later, all the groups had lower viable E. faecalis than the saline control. The bacterial penetration was also lowest in the NaOCl group, although there was no difference in bacterial viability in the tubules between the groups.

CONCLUSION

In primary teeth, NaOCl and CHG showed similar degrees of bacterial elimination efficacy in terms of E.faecalis.

CLINICAL RELEVANCE

Within the limitations of this study, NaOCl and CHG have the similar ability to perform endodontic irrigation of primary ex vivo teeth regarding the elimination of E.faecalis, but NaOCl penetrates dentin tubules better.

Iontophoresis use for increasing drug penetration into root canals and dentinal tubules: A proof-of-concept study

INTRODUCTION

The success of endodontic treatment depends on the significant disinfection of the root canal system, its irregularities, and dentinal tubules. However, achieving complete disinfection remains challenging, with frequent failures and occurrence of secondary infections. Here, we propose using iontophoresis to increase the penetration and distribution of disinfecting agents into root canals, using methylene blue for proof-of-concept.

METHODS

The marker was applied in bovine root canals, and the radial distribution of the dye in the dentinal tubules was evaluated by optical microscopy. Iontophoresis was applied at 0.5 and 1.5 mA for 5 and 15 min.

RESULTS

A significant statistical difference (p < 0.05) was observed in the marker penetration between passive and iontophoretic applications. Both current density and application time had an important effect on methylene blue distribution, with a greater efficacy delivery to the apical region achieved after 1.5 mA for 5 min or 0.5 mA for 15 min, showing longer application time can compensate for lower application current.

CONCLUSION

Iontophoresis increases the penetration and distribution of methylene blue into bovine root canals and dentinal tubules, including its innermost portions.

CLINICAL SIGNIFICANCE

Iontophoresis has shown to be a promising technique for root canal and dentinal tubule disinfection.

Periapical bacterial disinfection is critical for dental pulp regenerative cell therapy in apical periodontitis in dogs

BACKGROUND

Application of pulp regenerative cell therapy for mature teeth with periapical lesions is a critical clinical challenge. The bacterial infection in inaccessible location within the root canal system and in the periapical lesions could cause resistance and impediment, leading to limitations in successful therapy. Thus, the aim of this study was to examine the effect of residual bacteria on the outcome of pulp regeneration in mature teeth with apical periodontitis in dogs.

METHODS

Periapical lesions were induced in 32 root canals of 4 dogs in two different models in severities, model A and model B. Model A (moderate infection): the canal exposed to the oral cavity for 2 weeks and then closed for 2 weeks. Model B (severe infection): the canal exposed to the oral cavity for 2 months and then closed for 5 months. All root canals were irrigated with 6% sodium hypochlorite, and 3% EDTA and further with 0.015% levofloxacin-containing nanobubbles, which was also used as an intracanal medicament. The aseptic conditions were examined by bacterial anaerobic culture and/or PCR analyses. The root canal treatment was repeated several times, and allogeneic dental pulp stem cells were transplanted into the root canals. The radiographic evaluation of periapical lesions was performed by cone-beam computed tomography before the first treatment, just after cell transplantation, and after 2 months and 6 months in both model A, model B, respectively. The animals were then sacrificed and the jaw blocks were harvested for histological and histobacteriological evaluations of pulp regeneration and periapical tissue healing. Furthermore, the DiI-labelled DPSCs were transplanted into the root canals after complete disinfection (n = 4) or without root canal treatment (n = 4) in the apical periodontitis model (model A) in one dog, and cell localization was compared 72 h after transplantation.

RESULTS

In 8 out of 12 canals from model A, and 10 out of 15 canals from model B, pulp regeneration with good vascularization, innervation, and a significant reduction in the radiolucent area of the periapical lesions were observed. However, in the other 4 canals and 5 canals from model A and model B, respectively, no pulp tissue was regenerated, and inflammation in the periapical tissue, and external resorption or healed external resorption were detected. The presence of residual bacteria in the periapical tissues and severe inflammation were significantly associated with inhibition of regenerated pulp tissue in these 9 unsuccessful canals (P < 0.05, each) (OR = 0.075, each) analyzed by multiple logistic regression analysis. For cellular kinetics, transplanted cells remained in the disinfected root canals, while they were not detected in the infected root canals, suggesting their migration through the apical foramen under the influence of inflammation.

CONCLUSIONS

A true pulp-dentin complex was regenerated in the root canal by the pulp regenerative therapy in mature teeth with apical lesions. The successful pulp regeneration was negatively associated both with residual bacteria and inflammation in the periapical tissue.

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.

Phage PEf771 for the Treatment of Periapical Periodontitis Induced by Enterococcus faecalis YN771

Enterococcus faecalis was the main causative bacteria of refractory periapical periodontitis (PP), there is a pressing need to explore effective methods for eradicating E. faecalis in patients with refractory PP. This study aimed to assess the anti-infective effectiveness of phage PEf771 in treating periapical inflammation in rats. We developed a rat model of PP through E. faecalis YN771 induction. Micro-computed tomography and hematoxylin-eosin staining were utilized to evaluate bone destruction and inflammation in experimental teeth for seven consecutive weeks. Subsequently, rats with PP caused by E. faecalis YN771 were treated with phage PEf771, calcium hydroxide preparation, and 2% chlorhexidine gel. The healing progress of bone defects and inflammation in the apical region was monitored over three consecutive weeks using imaging and histopathology assessments. The PP rat model was successfully developed, and bone destruction and inflammatory cell infiltration in the apical region of the experimental tooth peaked at 4 weeks. The area of bone destruction in rats treated with phage PEf771, calcium hydroxide preparation, and 2% chlorhexidine gel was significantly smaller than that in the untreated group. Phage PEf771, calcium hydroxide preparation, and 2% chlorhexi-dine gel all have the effect of promoting the healing of apical lesions. Therapeutic effects of phage PEf771 on periapical inflammation infected by E. faecalis YN771 enhanced with time. Phage PEf771 promoted the healing of apical lesions, presenting a promising new approach for the treatment of refractory PP using bacteriophages.

The effectiveness of single antibiotic paste nitrofurantoin V/S double antibiotic paste in alleviation of post-operative pain of patients suffering from symptomatic irreversible pulpitis-A randomized controlled trial

Objective

The present research evaluated and compared effectiveness between nitrofurantoin and double antibiotic paste in alleviating post-operative pain in patients suffering from symptomatic irreversible pulpitis.

Methods

There were 60 subjects enrolled who were allotted among three groups: Group 1 - Nitrofurantoin, Group 2 - double antibiotic paste, and Group 3 - Control. Succeeding access opening and chemo mechanical preparation, intracanal medicament was placed in the root canals. Using a numerical pain scale, pain scores were measured at the following time intervals: preoperative, 12, 24, 48, and 72 h. One-way ANOVA and post hoc statistical analysis were conducted, with a p-value of ⩽ considered as statistically significant.

Results

Preoperatively, most patients experienced moderate to severe pain. The patients in groups 1 and 2 reported considerable reduction in their pain scores (p ⩽ 0.001) on each time interval. However, patients in group 3 experienced a higher level of pain even at 72 h. No considerable distinction was found among participant's pain scores of groups 1 and 2 (p = 0.193).

Conclusion

For effective pain-relieving, both nitrofurantoin and double antibiotic paste can be successfully used in patients suffering from symptomatic irreversible pulpitis. However, when calcium hydroxide was used, patients experience high levels of pain.

Dental pathologies of endodontic origin and subsequent bacterial involvement - a literature review

Dental pathologies of endodontic origin are varied in nature, and include infectious and non-infectious causes. Through this review, we aim to provide a deeper understanding of the role of bacterial involvement and in the pathogenesis of endodontic pathologies, by reviewing the relevant literature on the most common bacterial species involved, and their capacity to organize as biofilms. Furthermore, we focus on the most important recent updates in the management of endodontic infections, from a multidisciplinary perspective.

Assessment of Quality and Readability of Online Patient-Centered Arabic Web-Based Knowledge About Apicoectomy

Background Endodontic microsurgery (apicectomy) can be considered in cases of persistent infection that is resistant to conventional root canal treatment. The aim of this study was to evaluate the quality and readability of the available online information regarding the apicectomy procedure in Arabic. Methods Online search on the three most commonly used websites (Google, Yahoo, and Bing) using one keyword. The first 100 websites from each search were analyzed for quality and readability using DISCERN instrument scores, the Journal of the American Medical Association (JAMA) benchmarks, the Health On the Net (HON) seal, Flesch Reading Ease Scores (FRES), Flesch-Kincaid Grade Level (FKGL), and the Simplified Measure of Gobbledygook (SMOG) Index. Results Searching using the Arabic translation for "root end resection surgery" revealed 349,900 websites. Following the inclusion criteria, 31 websites were selected and evaluated in this study. The selected websites belonged to either non-profit organizations or commercial websites. The quality of most of the selected websites received a moderate score (83.9%) using the DISCERN tool. None of the selected websites obtained the HON seal. Quality evaluation using the JAMA benchmarks revealed that currency was the most achieved item (45.2%), followed by authorship (22.6%). Evaluation of the readability of the selected websites using the FRES, FKGL, and SMOG showed that the included websites were considered readable. Conclusion Although the included websites were readable, the quality of the websites was moderate. There is an urgent need to create more trustworthy and readable websites explaining the different endodontic treatments.

Personalized Medicine Based on the Pathogenesis and Risk Assessment of Endodontic-Periodontal Lesions

Endodontic-periodontal lesions (EPLs) are chronic inflammatory lesions in the mouth caused by multiple factors. Both periapical and marginal periodontitis are characterized by infection and inflammation around the affected teeth, suggesting that the theory of complex systems might describe the progression of EPL. The diagnosis and treatment of EPLs are complicated by variations of this condition and difficulties distinguishing EPLs from other diseases. Technological advances in diagnostic and treatment methods, including cone beam computed tomography, microscopy, mineral trioxide aggregates, and periodontal regenerative treatment, have improved outcomes, even in untreatable teeth. However, treating EPLs with iatrogenic problems and/or severe periodontitis remains challenging. Assessing the risk of each EPL based on the possible pathogenesis of each EPL is essential for determining individualized treatment and optimizing personalized medicine for individual patients.

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

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

Role of Hydrogen Sulfide in Oral Disease

Oral diseases are among the most common human diseases yet less studied. These diseases affect both the physical, mental, and social health of the patients resulting in poor quality of life. They affect all ages, although severe stages are mostly observed in older individuals. Poor oral hygiene, genetics, and environmental factors contribute enormously to the development and progression of these diseases. Although there are available treatment options for these diseases, the recurrence of the diseases hinders their efficiency. Oral volatile sulfur compounds (VSCs) are highly produced in oral cavity as a result of bacteria activities. Together with bacteria components such as lipopolysaccharides, VSCs participate in the progression of oral diseases by regulating cellular activities and interfering with the immune response. Hydrogen sulfide (H2S) is a gaseous neurotransmitter primarily produced endogenously and is involved in the regulation of cellular activities. The gas is also among the VSCs produced by oral bacteria. In numerous diseases, H2S have been reported to have dual effects depending on the cell, concentration, and donor used. In oral diseases, high production and subsequent utilization of this gas have been reported. Also, this high production is associated with the progression of oral diseases. In this review, we will discuss the production of H2S in oral cavity, its interaction with cellular activities, and most importantly its role in oral diseases.

Porosity Distribution in Single Cone Root Canal Fillings Performed by Operators with Different Clinical Experience: A microCT Assessment

The objective of this study was to assess the porosity distribution of BioRoot RCS/single gutta-percha point root-canal fillings performed by a general dental practitioner and endodontist. Fourteen plastic models of maxillary premolars with two roots were selected and shaped with HyFlex EDM instruments to a size 40/0.04 taper and randomly divided into two experimental groups. A total of 14 canals in each group were obturated by two different operators with one HyFlex EDM size 40 gutta-percha point and BioRoot RCS sealer. The specimens were scanned with a high-resolution micro-computed tomography scanner, and the porosity of the fillings at the coronal, middle, and apical thirds of the root canals was qualified and quantified. The differences between groups and root-canal thirds were compared using Mann–Whitney, Friedman, and Wilcoxon tests with the significance level set at p < 0.05. The highest number of pores was observed in the apical third of root-canal fillings in both groups; however, the porosity distribution between the two groups was not significantly different in the apical and middle thirds (p > 0.05). Statistically significant differences were determined only in the coronal third (p < 0.05). The predominance of open pores was detected in all root-canal thirds and groups, with no significant differences in the number of open pores between the coronal and middle thirds (p > 0.05).

The influence of customization of glass fiber posts on fracture strength and failure pattern: A systematic review and meta-analysis of preclinical ex-vivo studies

OBJECTIVE

To perform a systematic review of the literature focused to evaluate in vitro function of prefabricated fiber posts with and without customization by additional auxillary fiber posts and composite resin on the fracture strength of wide or enlarged canals and the failure pattern.

METHODS

Six databases were used as primary search sources (PubMed, Scopus, LILACS, SciELO, Science Direct, and Web of Science) and three databases (Open Grey, Open Thesis, and OATD) were used to partially capture the "grey literature". The research included laboratory studies that used human upper anterior teeth aiming to assess the fracture strength and failure pattern of different glass fiber post customizations by additional auxiliary fiber posts or composite resin. The search had no restriction of year, language, and publication status. The risk of bias of the studies was assessed from the criteria established in systematic reviews of laboratory studies. Standardized mean differences were calculated by comparing the mean fracture strengths of customized and non-customized posts. Pooled estimates were calculated by Glass' delta method using the random-effects model. Subtotal estimates were presented according to each type of relining procedure and an overall estimate was described considering all studies combined.

RESULTS

The search provided 2291 results, from which six met the eligibility criteria and were included in the qualitative assessment of the review. Only three studies presented a moderate risk of bias. The meta-analysis results showed that the use of auxiliary posts produced higher mean fracture strengths than non-customized posts (SMD = 2.21; 95%CI: 0.74; 3.68), and it was more effective than the use of composite resin to reline the posts.

CONCLUSION

Based on laboratories studies, even though has not been observed any difference to a statistically significant level on fracture strength and failure pattern of the customized and non-customized post, future studies should follow a standardized approach to implementation and reporting of data.

Comparison of Cone Beam Computed Tomography and Digital Radiography in Detecting Separated Endodontic Files and Strip Perforation

The separation of endodontic files and strip perforation are among procedural intraoperative complications which may ultimately lead to the failure of root canal treatment. The aim of the present study was to compare the diagnostic potential of cone beam computed tomography (CBCT) and digital periapical radiographs in detecting separated rotary files and strip perforation in filled canals. Fifty human mandibular molars were selected for this study. The teeth were randomly divided into two groups based on endodontic errors (i.e., file separation and strip perforation). In each group, 25 of 50 mesial canals were randomly chosen for simulating the errors, while the other 25 canals were considered as the control group. In group one, a simulation of the separation of rotary files was performed using ProTaper F2 files. Strip perforation of the root canals in group two was achieved by number 2 and 3 Gates Glidden drills in the coronal third of the root canals. Digital periapical radiographs in two different horizontal angles and high-resolution CBCT scans were obtained from the teeth mounted on a dry human mandible with simulated soft tissue covering. Three experienced observers who were unaware of the study groups evaluated the digital periapical and CBCT image sets in two separate readings. Intraobserver and interobserver agreements, as well as accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), were calculated and compared. Intraobserver and interobserver agreements ranged from poor to excellent and poor to good, respectively. The accuracy, sensitivity, specificity, PPV, and NPV for digital radiography in detecting separated files were 0.950, 0.813, 0.957, 0.929, and 0.880, respectively. The same values for CBCT were 0.747, 0.667, 0.900, 0.833, and 0.783, respectively. For the diagnosis of strip perforation, these values were 0.855, 0.800, 0.909, 0.889, and 0.833 for periapical radiography and 0.955, 1.000, 0.920, 0.926, and 1.000 for CBCT. In conclusion, CBCT was superior for diagnosing strip perforation of the filled root canals, while digital periapical radiographs performed better in the detection of separated rotary files.

[Clinical and radiological assessment of the anatomical and topographic structure of the root canals of teeth in patients of different age groups]

THE AIM OF THE STUDY

Was to identify the features of the anatomical structure of the root canals of teeth according to CBCT data in patients in different age groups.

MATERIAL AND METHODS

Patients of europeoid race, both sexes, who have indications for endodontic treatment (60 people), were divided into three groups: group 1 (young) 20 people aged 18 to 44 years, group 2 (middle age) 20 people - from 45 to 60 years, group 3 (elderly) 20 people - from 61 to 75 years old. To assess the root canal anatomy, all patients underwent x-ray examination (CT) on a Vatech computed tomography and analyzed with the Ez3D plus program before beginning endodontic treatment. The object of study was the first molars of the lower jaw (distal root canal).

RESULTS

The analysis of axial, sagittal, coronal sections of the first molar of the lower jaw revealed that patients belonging to the 1^st group, the distal root canal often had an oval shape all over (95%) and over a wide apical opening, in only one case out of 20 (5%) were identified at slit-like form of the distal root canal, probably due to malocclusion or as a consequence of increased abrasion of teeth. In group 2, two independent root canals were identified in the distal root of the first lower molar (in 65%), extending from the tooth cavity to the apex.in 35% of cases, the distal root canal began with a single entrance in the oral part and bifurcated into two separate channels at about the level of 2 /3 canals, then re - joined into a single apical opening, in group 3, in 75% of cases, a slit-like form of the distal root canal was observed. The obtained CLCT data (taking into account the image error) were confirmed in the clinic at the stage of endodontic treatment using optical magnification (microscope).

CONCLUSION

CBCT and operation microscopy with x40 magnification data showed clear age-dependent variations of first lower molar distal root canal anatomy.

Assessment of fractures in endodontically treated teeth restored with and without root canal posts using high-resolution cone beam computed tomography

Background

Root fractures are a diagnostic challenge for dentists in endodontic treatment. This study aimed to determine the relationship between the characteristics of tooth fractures and the presence of root canal posts in endodontically treated teeth using high-resolution cone beam computed tomography (CBCT).

Material and Methods

Fifty high-resolution CBCT scans of endodontically treated teeth with a diagnosis of fracture were obtained, of which 30 were from women and 20 were from men. These scans were acquired with three Veraviewepocs 3D units and one 3D Accuitomo 170 unit, with a 40 × 40-mm field of view and 125 μm voxel size. The variables assessed included the type of fracture, extent of fracture, type of retention, post length, cause of endodontic failure, location of the lesion, and time required to detect the fracture (difficulty score). For data analysis, the chi-squared test, Student’s t-test, and multiple linear regression (α <0.05) were used.

Results

No association was found between the type of fracture and type of retention or between the type of fracture and its extent (P>0.05). On the other hand, the type of fracture significantly influenced the time required for its detection. Additionally, the most difficult plane for detecting the fracture and the difficulty score were associated, with statistically significant results.

Conclusions

The type of fracture in endodontically treated teeth was not associated with the type of post used for restoration. All of the CBCT systems used to detect tooth fracture showed the same efficiency.

Key words:Cone-Beam CT, Tooth Fracture, Root Canal Post.

Differences in the corono-apical location of sinus tracts and buccal cortical bone defects between vertically root-fractured and non-root-fractured teeth based on periradicular microsurgery

This retrospective study aimed to investigate whether the corono-apical location of sinus tracts differs according to the presence/location of vertical root fracture (VRF) in microsurgically treated root-filled teeth. The cases included were (1) anterior and premolar teeth without a preoperative diagnosis of VRF, (2) those with a periodontal probing depth of ≤3 mm, and (3) those for which preoperative cone-beam computed tomography (CBCT) scans and intraoperative video records were available. VRF was diagnosed intraoperatively. The locations of buccal cortical bone defects and fracture lines were categorized on video images, and the corono-apical sinus tract locations were determined by superimposing video images onto volume-rendered CBCT images. Eleven of the 78 teeth investigated had VRF, and there was no significant difference in the incidence of sinus tracts between vertically fractured and non-fractured teeth (Mann-Whitney U-test, P > 0.05). The location of the sinus tract was significantly more coronal in vertically fractured than in non-fractured teeth (Mann-Whitney U-test, P < 0.0001). The location of sinus tracts was high correlated with cortical bone defects (Spearman's correlation, P < 0.0001). In microsurgically treated anterior and premolar teeth with a normal probing depth, sinus tracts were located more coronally in vertically fractured than in non-fractured teeth, and were highly correlated with the location of cortical bone defects.

Management of Discolored Failure Root Canal-Treated Upper Lateral Incisor

Root canal treatment failure can be determined based on a patient’s complaint and on the basis of clinical examination and radiographic findings. Most of the signs and symptoms for the failure are pain and discomfort, swelling and sinus formation at the surrounding soft tissue, and discoloration of the subjected tooth. Factors such as mechanical perforation during the procedures, overfilled or underfilled root canal, and missed or unfilled canals are the main factors for the failure outcome. This case report presents a discolored and infected upper lateral incisor which was previously root canal treated. The tooth was successfully managed under nonsurgical and surgical retreatment followed by an internal bleaching and full porcelain veneer. Apical tissue healing and acceptable tooth appearance was observed during a 12-month review.

Sealing Ability of Endodontic Cements: An In Vitro Study

The root canal system must be obturated using a hermetic seal to prevent the penetration of microorganisms and bacterial toxins into the endodontic system. The principles of adhesive dentistry have been increasingly used in endodontics. In fact, resin-based sealers are increasingly used. The objective of this study was to evaluate, in vitro, the sealing ability of resin cement in comparison with calcium hydroxide-based cement. Materials and Methods. Eighty root canals were prepared with the Tilos system and were randomly divided into four groups according to the filling material. The best combination was evaluated on the basis of its sealing ability. The dye infiltration degree was evaluated using both a stereomicroscope after diaphanization and the dye rise test. Results. A significant difference was observed between the four obturation systems with regard to the number of infiltrated walls (p=0.014) and the infiltration depth (p=0.025). The group of teeth obturated with EndoREZ® and EndoREZ® gutta cones differ significantly from the group obturated with EndoREZ® cement and gutta-percha cones in terms of apical sealing (p=0.011). A significant difference was also observed between the group of teeth obturated using EndoREZ® gutta cones and EndoREZ® cement and the group of teeth obturated with EndoREZ® cement (p=0.026). Conclusion. When used with EndoREZ® gutta cones, EndoREZ® cement showed the best sealing ability, particularly in the apical region. When used with gutta-percha cones, Acroseal and EndoREZ® cements exhibited similar sealing abilities.

Single crowns on tooth root-resected molars: A retrospective multicentric study

STATEMENT OF PROBLEM

Data regarding single restorations on molars treated with root resection and separation are limited.

PURPOSE

The purpose of this retrospective study was to evaluate the clinical success and survival of single crowns on root-resected molars.

MATERIAL AND METHODS

Eighty-six molars were treated with root resection or hemisection, prepared with feather-edge margins and restored with single crowns in 73 patients. The patients were clinically evaluated during regular recall appointments in 2018. Data were analyzed with descriptive statistics.

RESULTS

The mean follow-up time was 88.7 months (standard deviation, 70.6; range, 6 to 284). Six failures were recorded during the observation period, with a cumulative survival rate of 93%.

CONCLUSIONS

In this retrospective evaluation, single crowns on root-resected molars with feather-edge margins had clinical outcomes similar to those reported for single crowns on implants in the molar area. First molars and molars with 2 retained roots showed a better survival rate than second molars.

Complicated Root Canal Morphology of Permanent Mandibular Lateral Incisors is Associated with the Presence of a Second Mesiobuccal Canal in Permanent Maxillary First Molars

Many studies have been conducted in order to define the root canal morphology based on age, gender, ethnic and racial characteristics of the population. However, relations within morphological variations of certain groups of teeth have rarely been investigated. The aim of this study was to evaluate the root canal morphology of mandibular lateral incisors and to determine the association between their morphologic characteristics and the presence of a second mesiobuccal canal of maxillary first molars. Cone-beam computed tomography images from a pre-existing base were analyzed for the bilateral presence of both permanent mandibular lateral incisors and permanent maxillary first molars. Root canal morphology was analyzed according to the Vertucci classification. Associations of root canal morphologies between incisors and molars were calculated as probabilities using binary logistic regression analysis. In total, 126 mandibular lateral incisors and 126 maxillary first molars were included. 46% of all mandibular lateral incisors showed complicated root canal morphology and Vertucci type III canal configuration as the most frequent. Second mesiobuccal root canal was present in 62.7%. Root canal morphologies showed high level of bilateral symmetry in both tooth groups. The probability of a subject having complicated root canal morphology in lateral incisors was significantly higher when the second mesiobuccal canal was present. Clinicians should consider all available information on patients’ root canal morphology when planning new endodontic treatment. Root canal morphology of permanent mandibular lateral incisors showed high association with the root canal morphology of permanent maxillary first molars.

Graphene Family Nanomaterials: Properties and Potential Applications in Dentistry

Graphene family nanomaterials, with superior mechanical, chemical, and biological properties, have grabbed appreciable attention on the path of researches seeking new materials for future biomedical applications. Although potential applications of graphene had been highly reviewed in other fields of medicine, especially for their antibacterial properties and tissue regenerative capacities, in vivo and in vitro studies related to dentistry are very limited. Therefore, based on current knowledge and latest progress, this article aimed to present the recent achievements and provide a comprehensive literature review on potential applications of graphene that could be translated into clinical reality in dentistry.