Effect of restoration technique on resistance to fracture of endodontically treated anterior teeth with flared root canals

This study was designed to compare the impact of post and core systems on resistance to fracture of endodontically treated anterior teeth with flared root canals and to assess their fracture pattern. Sixty central incisors were cut horizontally 2 mm coronal to the cementoenamel junction(CEJ). After root canal therapy, teeth were assigned into 6 groups(n = 10 each) based on a post system and used as follows: Group C, non-flared root received size #1 glass fiber posts(Control); Group AP, flared root restored with anatomical post; Group RC, flared root restored with size #1 fiber post and cemented with thick layer of resin cement; Group CR, flared root restored with size #1 and reinforced with composite resin; Group CM, cast post-core; Group CP, CAD/CAM polymer-infiltrated ceramic post and core.Following post cementation, core build-up and crown insertion, the specimens were thermo-cycled up to 10,000 cycles(5 C/55 C; 30 seconds dwell time, 6 seconds transition time) and then statically loaded at 1 mm/minute crosshead speed using a universal testing machine. One-way ANOVA and Tukey HSD post hoc test(α= 0.05) were used for data analysis. Group C recorded significantly higher resistance to fracture values [(826.9±39.1) N] followed by group CP [(793.8±55.6) N] while group RC yielded the lowest fracture resistance values [(586.7±51.4) N]. The resistance to fracture of wide root canals can be enhanced by using one-piece CAM/CAM post and core as an alternative to the use of either glass fiber post, relined with composite resin increasing the thickness of luting cement or the use of cast post and core system. However, this was an in vitro investigation and further in vivo studies are necessary.

Effect of restorative techniques on fracture resistance of endodontically treated premolars

Purpose: This study was aimed to evaluate the effect of restorative materials and glass fiber post on the fracture resistance of endodontically treated premolars. Material and Methods: Fifty extracted single rooted lower premolars were used in this in vitro study and divided into 5 groups: sound teeth (control group);mesial-occlusal-distal (MOD) preparation + endodontic treatment + composite restoration;MOD preparation + endodontic treatment + glass fiber post + composite restoration;MOD preparation + endodontic treatment + amalgam restoration;MOD preparation + endodontic treatment + glass fiber post + amalgam restoration. The specimens were loaded on a universal testing machine at the crosshead speed of1 mm/min until fracture. The data were analyzed using two-way ANOVA test. Results: The mean loads at fracture were 860.11 N, 801.79 N, 761.39 N, 737.14 N and 707.85 N respectively. There were no statistically significant differences (P > 0.05) in the fracture resistance of teeth restored with composite and amalgam, as well as restored with or without glass fiber post. Conclusions: The type of restorative material and the usage of glass fiber post do not have visible influence on the fracture resistance of the endodontically treated mandibular premolars.

Convenient model of hard tissue simulation for dental radiographic research and instruction

BACKGROUND The authors describe a technique for building an alternative jawbone phantom using dental gypsum and rice for research and dental radiology instruction.AIM To investigate the potential of an alternative phantom to simulate the trabecular bone aspect of the human maxilla in periapical radiographs.METHODS Half-maxillary phantoms built from gypsum-ground rice were exposed to X-rays,and the resulting images(experimental group)were compared to standardized radiographic images produced from dry human maxillary bone(control group)(n=7).The images were blindly assessed according to strict criteria by three examiners for the usual trabecular aspects of the surrounding bone,and significant differences between groups and in assessment reliability were compared using Fisher’s exact and kappa tests(α=0.05).RESULTS The differences in the trabecular aspects between groups were not statistically significant.In addition,interobserver agreement among observers was 0.43 and 0.51 for the control and experimental groups,respectively,whereas intraobserver agreement was 0.71 and 0.73,respectively.CONCLUSION The tested phantom seemed to demonstrate potential for trabecular bone image Munhoz EA et al.Model of hard tissue simulation for dental radiography WJM https://www.wjgnet.com 2 March 20,2024 Volume 14 Issue 1 simulation on maxillary periapical radiographs.

Effect of Application of One-Time Method and Multiple Root Canals on Cryptic Fracture with Endodontic Lesions and VAS Score

Objective:To evaluate the therapeutic efficacy of primary method root canal treatment(ORCT)and multiple root canal treatment(MRCT)for dental cryptocleidosis with endodontic lesions.Methods:88 patients with fissured teeth with endodontic lesions who were admitted to the hospital between November 2021 and November 2023 were selected,and after randomized numerical table grouping,44 cases in the experimental group were included in the ORCT treatment,and 44 cases in the reference group were included in the MRCT treatment,and the total effective rate,root canal filling rate,visual analog scale(VAS)score,periodontal indexes,and the complication rate were compared.Results:The total effective rate and root canal filling rate of the experimental group were higher than that of the reference group;after treatment,the VAS score of the experimental group was lower than that of the reference group,and the periodontal indexes were lower than that of the reference group;and the complication rate of the experimental group was lower than that of the reference group(P<0.05).Conclusion:ORCT can improve the overall efficacy of patients with fissured teeth with endodontic lesions,ensure the filling rate of root canals,significantly reduce pain symptoms,improve a number of periodontal indicators,have high endodontic safety,and have more therapeutic advantages than MRCT.

Evaluation of the Effectiveness and Safety of One-Time Endodontics in the Treatment of Chronic Apical Periodontitis with Sinus Tract in Pediatric Deciduous Teeth

Objective:To observe the effectiveness and safety of one-time endodontics in the treatment of chronic apical periodontitis with sinus tract in pediatric deciduous teeth.Methods:109 cases of children with chronic apical periodontitis with sinus tract in the deciduous teeth treated in our hospital from January 2022 to December 2023 were selected and grouped by the randomized numerical table method,with 54 cases in the experimental group and 55 cases in the control group.The experimental group was treated with one-time endodontics and the control group was treated with conventional endodontics.Results:After the treatment,the total effective rate of treatment was higher in the experimental group than in the control group(P<0.05);the incidence of adverse events was lower in the experimental group than in the control group(P<0.05);the satisfaction of the children's family members was higher in the experimental group than in the control group(P<0.05);the pain duration was lower in the experimental group than in the control group(P<0.05).Conclusion:In the experimental group,children with chronic apical periodontitis with sinus tract of the deciduous teeth were given one-time endodontic treatment,and the results of its implementation were relatively good.

Clinical Value of Endodontic Patients Treated with Calcium Hydroxide Preparations

Objective: To investigate the clinical value of endodontics patients treated with calcium hydroxide preparation. Methods: The study cases were selected from the endodontics patients who visited our hospital during the period from January 2022 to December 2023, and 97 cases were randomly selected according to the numerical table method and divided into two groups. There were 49 cases in the control group and 48 cases in the experimental group. The control group received conventional therapy, while the experimental group received treatment with calcium hydroxide preparation, and the clinical value of the two different treatment modalities was observed and analyzed. Results: In the experimental group, 45 out of 48 patients (93.75%) showed effectiveness, compared to 39 out of 49 patients (79.59%) in the control group. The effectiveness rate was significantly higher in the experimental group (P < 0.05). Initially, the VAS scores between the two groups were similar (P > 0.05), but after 1 and 3 months of treatment, the scores decreased in both groups. However, the experimental group had a greater decrease, indicating lower pain levels (P < 0.05). The experimental group had fewer complications (8.33%) compared to the control group (24.49%), with a significant difference (P < 0.05). Satisfaction with treatment was higher in the experimental group (95.83%) compared to the control group (95.83%), resulting in an overall higher satisfaction rate in the experimental group (83.67%;P < 0.05). Conclusion: The treatment effect of endodontics with calcium hydroxide preparation is remarkable, which not only can effectively help patients to relieve their pain and reduce the incidence of complications but also plays an important role in improving patients’ satisfaction with treatment, which is worthwhile to be vigorously promoted in the clinic and learn from it.

Application of advanced platelet-rich fibrin for through-and-through bony defect during endodontic surgery:Three case reports and review of the literature

BACKGROUND The use of advanced platelet-rich fibrin(A-PRF)membranes for guided bone and tissue regeneration in through-and-through defects after endodontic surgery was explored in three cases.CASE SUMMARY Herein,three patients presented to the endodontic clinic suffering from apical periodontitis,associated with large bone resorption and related to previously endodontically treated teeth.Periapical surgery was indicated in these cases and the osteotomy site was covered by A-PRF membrane.Cone-beam computed tomography(CBCT)was used to assess the cases before and after the surgery.CONCLUSION Four months post-surgery,the recall CBCT scan showed complete obliteration of the osteotomy with newly formed bone.A-PRF membrane showed promising results and was an advantageous addition to surgical endodontic treatment.

Epigenetic regulation of dental pulp stem cells and its potential in regenerative endodontics

Regenerative endodontics(RE)therapy means physiologically replacing damaged pulp tissue and regaining functional dentin–pulp complex.Current clinical RE procedures recruit endogenous stem cells from the apical papilla,periodontal tissue,bone marrow and peripheral blood,with or without application of scaffolds and growth factors in the root canal space,resulting in cementum-like and bone-like tissue formation.Without the involvement of dental pulp stem cells(DPSCs),it is unlikely that functional pulp regeneration can be achieved,even though acceptable repair can be acquired.DPSCs,due to their specific odontogenic potential,high proliferation,neurovascular property,and easy accessibility,are considered as the most eligible cell source for dentin–pulp regeneration.The regenerative potential of DPSCs has been demonstrated by recent clinical progress.DPSC transplantation following pulpectomy has successfully reconstructed neurovascularized pulp that simulates the physiological structure of natural pulp.The self-renewal,proliferation,and odontogenic differentiation of DPSCs are under the control of a cascade of transcription factors.Over recent decades,epigenetic modulations implicating histone modifications,DNA methylation,and noncoding(nc)RNAs have manifested as a new layer of gene regulation.These modulations exhibit a profound effect on the cellular activities of DPSCs.In this review,we offer an overview about epigenetic regulation of the fate of DPSCs;in particular,on the proliferation,odontogenic differentiation,angiogenesis,and neurogenesis.We emphasize recent discoveries of epigenetic molecules that can alter DPSC status and promote pulp regeneration through manipulation over epigenetic profiles.

Endodontic management of the maxillary first molars with two root canals: A case report and review of the literature

BACKGROUND The complex anatomy of the maxillary first molars has always been a major challenge for complete root canal treatment in endodontic therapy. Here, we present two cases of maxillary first molars, each with only two root canals, which have been rarely reported. We also perform a literature review of maxillary first molar anatomy.CASE SUMMARY The two patients were referred to the hospital after 1) finding a cavity in their tooth with a color change and, 2) a toothache during mastication, respectively.Both of these cases were diagnosed as apical periodontitis by X-ray imaging and cone beam computed tomography(CBCT). Non-surgical endodontic therapy was performed with the assistance of a dental operating microscope(DOM). CBCT showed rare but accurate images of both patients, each with two root canals and two roots in their maxillary first molars. Both roots were located in the buccal in the palatal direction, and each root had only one clear root canal. In addition,each maxillary first molar in both patients was symmetrical to that on the opposing side with only two separate root canals. Non-surgical endodontic therapy was performed with the assistance of a DOM. Finally, the teeth were restored using composite resin and the patients were satisfied with the results.CONCLUSION Making full use of CBCT and DOM would contribute to helping dentists make correct diagnoses and successfully treat teeth with rare root canal morphologies.

Effectiveness and Safety of Computer-controlled Periodontal Ligament Injection System in Endodontic Access to the Mandibular Posterior Teeth

Objective To evaluate the effectiveness and safety of a computer-controlled periodontal ligament （PDL） injection system to the local soft tissues as the primary technique in endodontic access to mandibular posterior teeth in patients with irreversible pulpitis. Methods A total of 162 Chinese patients who had been diagnosed with irreversible pulpitis in their mandibular posterior teeth without acute infection or inflammation in the periodontal tissues were enrolled in this clinical study. The patients were divided into 3 groups according to the position of the involved tooth： the premolar group （PM, z2=38）, first molar group （FM, n=66）, and second molar group （SM, n=58）. All the patients received computer-controlled PDL injection with 4% articaine and 1 ＇ 100 000 epinephrine. Immediately after the injection, endodontic access was performed, and the degree of pain during the treatment was evaluated by the patients using Visual Analogue Scale for pain. The success rates were compared among the 3 groups. The responses of local soft tissues were evaluated 3-8 days and 3 weeks after the procedure. Results The overall success rate was 76.5%. There was a significant difference in success rates among the PM, FM, and SM groups （92.1%, 53.0%, 93.1%, respectively; 2 X =34.3, P〈0.01）. Both the PM and SM groups showed higher success rates than that of the FM group （v=l, f=16.73, P〈0.01, v=l, Z = 4.5, X2 2 P〈0.01）. No irreversible adverse effects on the periodontal soft tissues at the injection sites were observed in the follow-up visits in any of the groups. Conclusion The computer-controlled PDL injection system demonstrates both satisfactory anesthetic effects and safety in local soft tissues as primary anesthetic technique in endodontic access to the mandibular posterior teeth in patients with irreversible pulpitis.

Prevalence of Enterococcus faecalis in saliva and filled root canals of teeth associated with apical periodontitis

To investigate the prevalence of Enterococcus faecalis in saliva and filled root canals of patients requiring endodontic retreatment for apical periodontitis.Patients with apical periodontitis who were referred for endodontic retreatment were examined.The type and quality of the restoration,symptoms,quality of obturation were recorded.During retreatment,an oral rinse sample and root canal sample were cultured using brain-heart infusion agar and bile esculinazide agar to select for E.faecalis.The 16S rRNA technique was used to identify E.faecalis.A total of 32 women and 22 men（mean age：38 years;s.d.：11 years） and 58 teeth were studied.The prevalence of E.faecalis was 19% in the saliva and 38% in the root canals.The odds that root canals harbored E.faecalis were increased if the saliva habored this bacterium（odds ratio59.7;95% confidence interval51.8-51.6;P,0.05）.Teeth with unsatisfactory root obturation had more cultivable bacterial species in root canals than teeth with satisfactory root obturation（P,0.05）.E.faecalis is more common in root canals of teeth with apical periodontitis than in saliva.The prevalence of E.faecalis in root canals is associated with the presence of E.faecalis in saliva.

Three-dimensional inlay-guided endodontics applied in variant root canals: A case report and review of literature

BACKGROUND Root canal retreatment is common after root canal therapy in clinical situations.Especially,completing the retreatment of variant root canals can be challenging.This is particularly true for the molars located at the end of the dental arch.However,advancements in digital dental diagnosis and treatment techniques can solve these problems.Here,we describe a case of a maxillary second molar with a variant distobuccal root canal treated via a novel“inlay-guided endodontics”technique based on improved computer-generated programs.CASE SUMMARY A 63-year-old man complained of a defect in the maxillary left second molar.The tooth,diagnosed with post-treatment endodontic disease,was initially treated by conventional methods,which were ineffective.Our“inlay-guided endodontics”technique was subsequently adopted,with the establishment of a precise integrated three-dimensional(3D)plate model of cone-beam computed tomography data and a digital impression of the dentition.An optimal root canal approach was generated for the“virtual file”in the 3D model.The plate data were imported into a 3D printer and printed.With the help of the guide plate,the file was accurately placed into the cervical third of the distal root canal.The root canal and prosthodontic treatments successfully proceeded subsequently.CONCLUSION Our newly developed inlay guide plates may facilitate individualized and minimally invasive root canal treatment.

Conservative endodontic management using a calcium silicate bioceramic sealer for delayed root fracture:A case report and review of the literature

BACKGROUND The success rate of conservative endodontic management for root fracture varies greatly based on different methods used.It has been rarely reported that calcium silicate-based materials are applied in root fracture treatment.CASE SUMMARY A 38-year-old male patient presented with spontaneous pain from the upper left anterior teeth for 1 wk.The spontaneous pain was subsequently relieved,but pain on mastication persisted for 3 d.The patient had a dental trauma from a boxing match 15 years ago.Cone beam computed tomography showed that the maxillary left central incisor had oblique fracture lines and a radiolucent lesion around the fracture line.The tooth was diagnosed with an oblique root fracture with no healing and symptomatic apical periodontitis.In the following conservative endodontic management,the coronal and apical fragments of the canal both were chemo-mechanically prepared and obturated using a single cone gutta-percha with iRoot SP(Innovative BioCreamix Inc,Vancouver,Canada),a new calcium silicate-based bioceramic root canal sealer.At follow-ups at 1,6,12,and 24 mo,the patient was asymptomatic and the radiolucency around the fracture line was healing radiographically.CONCLUSION Conservative root canal treatment is an alternative treatment in some cases of oblique root fracture with no healing.The application of bioceramic sealers and single core obturation techniques may also be essential to obtain an excellent outcome.

Use of a new retrograde filling material(Biodentine) for endodontic surgery: two case reports

Mineral trioxide aggregate（MTA） is considered at the present time as the gold standard for root-end filling in endodontic surgery.However, this biocompatible material presents several drawbacks such as a long setting time and handling difficulties. The aim of this article is to present a new commercialized calcium silicate-based material named Biodentine with physical improved properties compared to MTA in a clinical application. Two endodontic microsurgeries were performed by using specific armamentarium（microsurgical instrumentation, ultrasonic tips） under high-power magnification with an operatory microscope. Biodentine was used as a root-end filling in order to seal the root canal system. The two cases were considered completely healed at 1 year and were followed for one more year. The 2-year follow-up consolidated the previous observation with absence of clinical symptoms and radiographic evidence of regeneration of the periapical tissues.

Six cases report of differential diagnosis of periapical diseases

The distinction of some particular forms of periapical area, involving diseases from regular periapical disease, is a matter of considerable importance when choosing a correct treatment. The aim of this study is to describe the differential diagnosis of F,eriapical diseases from six rare cases in clinical practice. The six rare cases are examples of situations where it is difficult to make a differential diagnosis in clinical practice. By retrospective surveys on the clinical examination, radiographs and pathological results, six patients referred to endodontic treatment in our department were analyzed for the accuracy of diagnosis and therapy. The pathoses of the six cases included two atypical radical cysts, periapical cemental dysplasia, cemento-ossifying fibroma, thymus cancer metastasis in the periapical site and tuberculosis. This report indicates that endodontists should be cognizant of a few particular circumstances when clinically treating periapical diseases.

Bilateral maxillary fused second and third molars:a rare occurrence

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography （CBCT）. A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.

Endodontic treatment of the maxillary first molar with palatal canal variations: A case report and review of literature

BACKGROUND Root canal variations frequently occur in maxillary first molars,which greatly affects the success of its treatment.The second mesiobuccal(MB)root canal is the most common root canal variation.However,only a few studies have been conducted on palatal root canal variations.Herein,we report the presence of two separate root canals in a palatal root of the maxillary first molar.CASE SUMMARY A 39-year-old woman complained of pain in the maxillary right region for 1 year,which recently worsened.Clinical examination revealed a poorly restored right maxillary first molar and caries detected at the filling marginal.Cold and heat test results indicated severe pain in the right maxillary first molar.The patient was diagnosed with irreversible pulpitis,and subsequently,root canal treatment(RCT)was performed.In total,five root canals were found in the maxillary first molar,including two separate root canals in the palatal root.RCT was successfully performed using an endodontic microscope and cone-beam computed tomography(CBCT).The CBCT image revealed a vertucci type I canal morphology in the distobuccal root,while the MB and palatal root canals were typeⅣ.At the 1-mo follow-up,the maxillary first molar was completely asy-mptomatic,and the X-ray results indicated a successful RCT.Finally,the ceramic crown restoration was performed.CONCLUSION An endodontic microscope and CBCT are useful in effectively identifying and treating root canal variations.

Nasal septal foreign body as a complication of dental root canal therapy: A case report

BACKGROUND Currently,there have been no reports on foreign bodies found in the nasal septum after dental root canal therapy.Herein,we present an unusual case of a foreign body found in the nasal septum,which occurred after dental root canal therapy and two unsuccessful surgeries.CASE SUMMARY A 55-year-old man was referred to our department due to slight nasal discomfort that persisted for about 1 wk.Before consulting our department,the patient visited three different hospitals/clinics and underwent two surgeries that were not successful in removing a foreign body completely.A computed tomography scan was performed to detect the shift of the foreign body from dental root to the nasal septum,which resulted in the healing of oral inflammation and nasal septum discomfort.An endoscopic foreign body extraction surgery(3rd removal surgery)was then successfully performed,using a needle as the reference.No nasal reconstruction was required after the operation.Postoperative healing was uneventful.CONCLUSION Medical healthcare professionals should consider past medical history when dealing with foreign body cases.During septal foreign body extraction surgery,a needle could be used as a helpful reference.

Endodontic management of a fused left maxillary second molar and two paramolars using cone beam computed tomography: A case report

BACKGROUND Fused teeth usually involve several complications,such as the development of caries in the groove between fused crowns,tooth impaction,diastemas,aesthetic and periodontal problems,and pulpal pathosis,due to the complex anatomical structure of fused teeth.A thorough diagnosis is paramount to forming an accurate treatment plan and obtaining a favourable prognosis.With the advent of cone-beam computed tomography(CBCT),accurate 3-dimensional images of teeth and their surrounding dentoalveolar structures can now be readily obtained,and the technology can accurately provide a minimally invasive approach to acquire detailed diagnostic information.Therefore,we utilize CBCT data herein to generate a digital model for the infected region in a patient,and this model enables us to better plan the management of his case.CASE SUMMARY This report details the diagnosis and endodontic treatment of a rare case involving a fused maxillary second molar and two paramolars with apical periodontitis.The patient experienced pain upon biting and cold sensitivity in the area of the maxillary left molar.No caries or other defects were identified in these teeth,and a normal response to a pulp electric viability test was observed.With the aid of CBCT and digital model technology,we initially suspected that the infection originated from the isthmus between the maxillary second molar and two paramolars.Therefore,we only treated the isthmus by an endodontic approach and did not destroy the original tooth structure;furthermore,the vital pulp was retained,and good treatment outcomes were observed at the 24-month follow-up.CONCLUSION This finding may provide new insights and perspectives on the diagnosis and treatment of fused teeth.

Clinical Endodontic Applications of Cone Beam-Computed Tomography in Modern Dental Practice

Nearly two decades since Cone Beam-Computed Tomography (CBCT) was introduced in dentistry, this technology has been proven to be a useful asset in modern dental practice. The information gleaned from a CBCT scan influences treatment decisions and prognostication of challenging endodontic cases. The authors present six cases that utilized CBCT to diagnose vertical root fracture, to assess resorption, to guide the clinician in overcoming anatomical complexities, to hurdle diagnostic dilemmas and to perform pre-surgical evaluation. Initially, a thorough clinical assessment was performed;however, conventional periapical radiographs were not able to provide sufficient information to arrive at a definite diagnosis or a thorough treatment plan. CBCT was therefore deemed helpful for these cases. Clearly, there are advantages to using CBCT. With a better understanding of each case, the clinician can plan a definitive treatment plan and offer a clearer case prognosis to their patient.