Root Fracture Research Articles

Cone Beam Computed Tomography Analysis of Post Space in Bifurcated Premolars Using ParaPost and Peeso Reamer Drills

Introduction Core buildups are usually maintained by the usage of posts. Even so, in curved and narrow canals, such as bifurcated premolars, excessive dentin removal during post-space preparation can result in a vertical root fracture or perforation. In order to preserve root canal dentin during post-space preparation of bifurcated premolars, this study examined and analyzed the effects of two widely used drills: Peeso Reamer (Dentsply Maillefer, Ballaigues, Switzerland) and ParaPost (Coltene/Whaledent, Inc., Altstätten, Switzerland). We also examined the risks associated with using Cone-beam Computed Tomography (CBCT). Methods Three operators with varying levels of experience treated a total of 72 removed bifurcated premolars, dividing them into equal groups. The rotary ProFile system (Dentsply Sirona, Charlotte, NC) was utilized for root canal treatments, and gutta-percha size #30/0.4 was used for obturation. Peeso Reamer #2 and ParaPost #1 were then used to prepare the palatal canals. CBCT was used to assess the total mean intracanal spaces of 3 mm, 5 mm, and 7 mm that were measured both preoperatively and postoperatively. To compare the mean dentin thickness within the canal area across all groups, we used analysis of variance testing. We detected complications, like deviations or perforations, using mesiodistal periapical radiographs. Results When utilizing the Peeso Reamer, the mean dentin thickness (0.749 mm) was slightly more than when using the ParaPost (0.736 mm) with p=0.16. There was no significant difference in the mean dentin thickness of the canal area between the Peeso Reamer and the ParaPost drills. The Pesso Reamer drill had fewer complications since it matched the canal configuration, while the Parapost drill removed somewhat more dentin in the canal area. Only seven teeth with minimum deviation from the center of the canal during preparation were produced by the Peeso Reamer drill (20% of teeth having deviation), whereas twenty-one teeth had deviations (72.2% of teeth) and eight had furcal perforations generated by the ParaPost. Conclusion Within the limitations of our study, the Pesso Reamer drill caused little more dentin removal than the ParaPost drill. However, the Peeso Reamer had fewer risks and was safer to use in bifurcated premolars. The ParaPost drill is not recommended in bifurcated premolars due to the high risks of deviation and perforation because they have narrow canals. The selection of an appropriate drill for post-space use in bifurcated premolars is essential for successful patient outcomes.

A narrative review on the current uses of artificial intelligence in endodontics

Abstract Artificial intelligence (AI) has been widely introduced to dentistry in the past decade. Its application in endodontics is limited to different areas such as working length determination, morphological assessment, detection of vertical root fracture, and the detection of periapical lesion. Therefore, this study aims to highlight the available evidence for the uses of AI in endodontics. It also presents the current status as well as the future perspectives on the uses of AI and its potential application in everyday practice. A literature search was conducted from January 2000 to January 2023 using PubMed and Google Scholar for the terms AI and endodontics. Thirty-one studies were evaluated and summarized, highlighting the potential use of different AI models in endodontics. The evaluation of the studies indicated that the use of AI is promising and could aid in tailored endodontics therapy. It would help the clinician in the detection of periapical radiolucency, root fractures, and determination of working length. However, well-designed, high-quality research is required to assess the possible implementation of AI into day-to-day practice in endodontics.

Effect of different intracanal medicaments combined with chitosan nanoparticles on microhardness and fracture resistance of root dentin – An in vitro study

Abstract Introduction: Chitosan nanoparticles (CSN) are widely used for endodontic disinfection; however, their combination with other intracanal medicaments is least studied; therefore, this study aims to evaluate the effect of various intracanal medicaments incorporated with 0.2% CSN on root dentin microhardness and fracture resistance. Materials and Methods: Fifty extracted human single-rooted premolars were cleaned, decoronated, and standardized to 13 mm root length. After access opening and working length determination, specimens were instrumented with ProTaper rotary files till apical size F3 and alternatively irrigated with 5 ml of 2.5% sodium hypochlorite and normal saline (NS). Final irrigation was done with 5 ml of 1% phytic acid. The specimens were allocated randomly into five groups (n = 10), followed by placement of intracanal medicament for 1 week as follows. Group 1 – 0.2% CSN, Group 2 – Calcium hydroxide (Ca[OH] 2) + 0.2% CSN, Group 3 – Triple antibiotic paste (TAP) + 0.2% CSN, Group 4 – Propolis + 0.2% CSN, and Group 5 – Chlorhexidine gluconate (CHX) + 0.2% CSN. The specimens were then rinsed with NS and 3 mm coronal portion of each specimen was horizontally sectioned to create dentin blocks that were further split vertically and tested for Vickers microhardness (n = 10). The remaining root segment of each specimen was then vertically embedded in an acrylic block and evaluated for fracture resistance (n = 10) under a universal testing machine. The data acquired were statistically assessed using one-way ANOVA and posthoc Tukey tests (P < 0.05). Results: Propolis incorporated with 0.2% CSN showed the highest microhardness and fracture resistance values followed by CHX + 0.2% CSN, TAP + 0.2% CSN, Ca(OH)2 + 0.2% CSN, and least in 0.2% CSN alone. Conclusion: Intracanal medicaments incorporated with 0.2% CSN exhibited a synergetic effect on microhardness and fracture resistance of endodontically treated teeth; however, propolis with 0.2% CSN exhibited higher microhardness and fracture resistance of root dentin.

Diagnostic accuracy of artificial intelligence versus dental experts in predicting endodontic outcomes: A systematic review

Abstract Introduction: In the rapidly evolving landscape of health care, artificial intelligence (AI) has emerged as a promising tool to enhance diagnostic accuracy across various medical disciplines. Within the realm of dentistry, one critical area of focus is endodontics, which involves the diagnosis and treatment of dental pulp diseases. This systematic review investigates the diagnostic precision of AI in contrast to dental experts when predicting endodontic outcomes. Materials and Methods: The review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The review was registered on the Open Science Framework database. A systematic search was performed of the literature on the application of AI versus dental experts in endodontics. The search was conducted on PubMed, Scopus, Web of Science, and OVID until December 2022. The QUADAS-2 tool was used to evaluate the risk of bias. Results: The initial search retrieved 972 records, of which eight articles were included in the study. The studies reported application of AI for working length determination, periapical lesions, pulp and tooth segmentation, apical periodontitis, vertical root fracture, and C-shaped canals. QUADAS-2 tool revealed a low risk of bias in five out of the eight included studies. Conclusion: AI models demonstrated a notable increase in accuracy and effectiveness in endodontic diagnosis and treatment planning. These results suggest that the integration of AI technology in endodontic diagnosis and treatment planning has immense potential to serve as a promising aid.

Application of '10 Keys' Checklist and Partial Extraction Techniques to Optimize Esthetic Outcome for Adjacent Implants in the Esthetic Zone.

Placing immediate implants in the esthetic zone area poses significant challenges. Implants should be placed with consideration to hard and soft tissue management to optimize long term implant and cosmetic success. In this case report, two maxillary central incisors were extracted in two different time points, separated by 5 years because of horizontal root fractures. Implants were placed according to immediate single-tooth guidelines, using two different surgical and loading approaches, as risk assessment factors changed in the time between first immediate placement (#8) and second immediate placement (#9). These techniques included Partial Extraction Therapy (PET), the use of allograft and growth factors, connective tissue graft (CTG), platelet rich fibrin (PRF) and immediate and conventional loading. These were grouped as the '10 keys', a checklist used to pursue long term success. After 6-year and 1-year follow-up, radiographic and clinical results were satisfactory.

Clinical, radiographic features and prognosis of cemental tear: A retrospective study of 63 teeth

Cemental tears are often misdiagnosed due to their scarcity. In this study, we reported the second largest cohort of cemental tears thus far. By reviewing the radiographic data and medical records of 63 cemental tear teeth, we found that periapical periodontitis was the most frequent diagnosis, followed by cracked tooth/root fracture and periodontitis. Most of the cemental tear teeth that did not have root canal treatment had vital pulp. The apical third of the root was the most prominent site of cemental tears. Cemental tears occurred more frequently in the palatal root of the maxillary molars and in the mesial root of the two-root mandibular molars. Uncontrollable bone loss and tooth mobility were the two main reasons for the extraction of teeth with cemental tears. We suggest that cemental tears should be included in the differential diagnosis of periapical periodontitis, cracked tooth, vertical root fracture and periodontitis, especially for teeth with periapical radiolucency and vital pulp. We believe our study could provide more insights into cemental tears, which will aid clinicians in the early diagnosis and proper treatment of cemental tears.

Intracanal medicaments and coronal sealing materials influence on root fracture resistance and coronal discoloration: An in vitro study

Abstract Introduction: Immature teeth are more susceptible to fracture, and intracanal medicaments and coronal filling materials used in regenerative endodontics affect their optic and mechanical properties. This study aimed to evaluate the fracture resistance and coronal discoloration of simulated immature teeth following the placement of several intracanal medicaments and coronal sealing materials. Materials and Methods: Eighty-eight premolars simulating immature teeth were divided into 11 groups (n = 8 each) according to the type of intracanal medicament (triple antibiotic paste [TAP]; double antibiotic pastes [DAP]; calcium hydroxide [Ca(OH)2]) and used coronal barrier materials (mineral trioxide aggregate [MTA] and calcium-enriched mixture [CEM]). A bonding agent was applied in half of the samples in the groups where antibiotic pastes were used (n = 8). After incubating for 3 weeks, the sample’s fracture resistance and color change were evaluated. Data analysis was conducted using multivariate and one-way analysis of variance, Tukey’s honestly significant difference post hoc, and the Kruskal–Wallis tests (α =0.05). Results: The color change after placing the medicaments was comparable among the groups. However, after 3 months, the color change in the TAP-CEM-No-Bonding group was higher than the control, Ca(OH)2-MTA, and DAP-MTA-No-Bonding groups (P < 0.05). The fracture resistance of the TAP-MTA-Bonding, DAP-CEM-Bonding, Ca(OH)2-MTA, and Ca(OH)2-CEM was lower than the control group (P < 0.05). Conclusion: Simultaneous use of DAP-MTA without a dentin bonding agent led to comparable color change and fracture resistance to the control group.

Comparative evaluation of the accuracy of two electronic apex locators in detecting simulated incomplete vertical root fractures: An in vitro stereomicroscopic study

Aim: The aim of this study was to compare the accuracy of two different electronic apex locators (EALs) in detecting simulated incomplete vertical root fractures (VRFs). Materials and Methods: Thirty freshly extracted single-rooted teeth were randomly divided into three groups of 10 teeth each labeled as Groups A, B, and C. Incomplete VRFs were simulated in the coronal, middle, and apical one-third of the roots for Groups A, B, and C, respectively. The teeth were embedded in alginate mold and fracture location was determined with Root ZX and Propex EALs for each sample and each group. To calculate the actual length (AL), each sample was sectioned at the upper level of the vertical fracture, and the length was measured by setting the stopper of the #10 K file under a stereomicroscope at ×30 magnification. The electronic lengths and ALs were compared using computer software, and the results were analyzed using SPSS 28.0 at a 95% confidence level. Results: No significant differences were seen in the accuracy of the two EALs when compared with ALs. Root ZX showed significantly longer measurements than ALs in groups B and C. Conclusion: The tested EALs showed low accuracy (20%) in detecting simulated incomplete VRFs with a tendency for longer measurements compared to ALs.

Dentistry's use of artificial intelligence: Past, Present, and Future.

The significance and use of artificial intelligence (AI) in dentistry and other industries has significantly increased. In the healthcare sector, particularly in endodontics, AI can replicate human intelligence to make complex predictions and decisions. Convolutional neural networks or artificial neural networks have shown promise in endodontics for various applications, including analyzing the anatomy of the root canal system, enhancing the viability of dental pulp stem cells, determining working lengths, identifying periapical lesions and root fractures, and predicting retreatment outcomes. Future applications of this technology, such as prognostic assessment, drug interactions, treatment planning, patient care, and automated endodontic surgery, have been considered. AI has demonstrated precision and accuracy. AI holds potential for improving endodontic treatment and diagnosis, ultimately leading to increased procedure effectiveness. However, before incorporating these models into routine clinical practices, it is essential to validate their usability, reliability, and accessibility. Keywords: Artificial intelligence in dentistry, Digital dentistry, use of AI in dentistry.

A novel surgical treatment approach for the vertical root fracture of posterior teeth: a case report with 24-month review

Background Up to 25% of the tooth extraction after root canal treatment could be attributed to the vertical root fracture (VRF). The treatment choice for teeth with VRF would mostly be the extraction despite some repairing methods were also reported. The repairing treatment result of VRF would mostly depend on the fixation strength and the bioactivity of the repairing materials, especially for the posterior teeth with high masticating stresses. This case report designed a novel surgical treatment approach for the VRF of posterior teeth.Methodsa maxillary premolar with buccal-palatal complete VRF was treated with a new dual-layered repairing approach using adhesive resin + iRoot BP Plus bioceramic cement to fill the modified fracture line with retention forms through the intentional replantation.ResultsAt the 24-month review, the tooth showed desirable periodontal healing and normal function.ConclusionsThis case report indicated that the dual-layered repairing approach might be effective for saving the posterior teeth with VRF. Nevertheless, further clinical trials are needed for its long-term result.

Frequency and Patterns of Traumatic Dental Injuries Reported at Islamabad Dental Hospital: A Retrospective Study.

Background: Traumatic dental injuries (TDIs) are increasingly becoming a public health concern, with a significant number of cases presenting to emergency departments worldwide. They affect a diverse age range, particularly children and adolescents, and are influenced by various etiological factors such as falls, sports injuries, and road traffic accidents. Previous studies have indicated a gender predisposition, with males more frequently affected, and a pattern of injury that varies by region. Objective: This study aimed to investigate the frequency and patterns of TDIs treated at the Department of Operative Dentistry, Islamabad Dental Hospital, and to analyze the management strategies employed. Methods: A retrospective cross-sectional analysis was conducted, examining patient records from 2015 to 2022. Approval was obtained from the institutional review board, aligning with the Declaration of Helsinki. Data from complete TDIs forms were extracted, detailing the type of injury, timing, and treatment administered. Statistical analysis was performed using SPSS v.23, with chi-square tests applied to examine the association between the type of trauma and demographic variables. Results: A total of 88 teeth with TDIs were recorded. The most common injuries were complicated crown fractures (28.4%) and root fractures (17.0%), with splinting (31.8%) and root canal treatments (29.5%) being the most frequent management procedures. Male patients were predominantly affected. Notably, adult cases surpassed those of children and adolescents, contrary to global trends. Conclusion: TDIs constitute a significant portion of dental emergency cases, with specific patterns and treatments that vary by demographics. Immediate and appropriate management, guided by current guidelines, is essential. Efforts should focus on increasing awareness and providing adequate training to healthcare providers for timely and effective treatment of TDIs.

Enhancing Aesthetic and Structural Integrity in Necrotic Permanent Incisor with Open Apex: A Case Report

Traumatic injuries in immature teeth often lead to complications in endodontic treatment due to difficulty in managing the open apex. Also, the restoration of these teeth poses significant challenges due to thin dentin walls, high configuration factors, and other biomechanical and adhesive issues. Standard fibre posts are often not suited for flared root canal preparations, leaving excessive cement space between the post and the tooth structure. To reduce postoperative complications (e.g. root fracture), reinforcement of radicular dentin becomes mandatory after endodontic treatment. The reinforcement of the canal can be done using a fibre post relined with composite resin. Direct anatomical posts offer a promising alternative that minimises the risk of debonding. This case report details the use of platelet rich fibrin as a internal matrix and how mineral trioxide aggregate can be used to form an immediate apical seal for apexification and a custom fiber post technique for reinforcing an immature maxillary central incisor in an 18-year-old patient. Keywords - Adhesive cement, Apical seal, Dentin reinforcement, Esthetics, Fiberglass, MTA, Post and core technique

Endoscopically-assisted extraction of broken roots or fragments within the mandibular canal: a retrospective case series study

PurposeTo assess the impact of endoscope-assisted fractured roots or fragments extraction within the mandibular canal, along with quantitative sensory testing (QST) alterations in the inferior alveolar nerve (IAN).MethodsSix patients with lower lip numbness following mandibular third molar extraction were selected. All patients had broken roots or fragments within the mandibular canal that were extracted under real-time endoscopic assistance. Follow-up assessments were conducted on postoperative days 1, 7, and 35, including a standardized QST of the lower lip skin.ResultsThe average surgical duration was 32.5 min, with the IAN exposed in all cases. Two of the patient exhibited complete recovery of lower lip numbness, three experienced symptom improvement, and one patient remained unaffected 35 days after the surgery. Preoperative QST results showed that the mechanical detection and pain thresholds on the affected side were significantly higher than those on the healthy side, but improved significantly by postoperative day 7 in five patients, and returned to baseline in two patients on day 35. There were no significant differences in the remaining QST parameters.ConclusionsAll endoscopic surgical procedures were successfully completed without any additional postoperative complications. There were no cases of deterioration of IAN injury, and lower lip numbness recovered in the majority of cases. Endoscopy allowed direct visualization and examination of the affected nerve, facilitating a comprehensive analysis of the IAN.

Dental injuries in Swiss children - an analysis of Swiss national health insurance data from the year 2019.

This study, the first to analyze accident data from a major compulsory Swiss health insurer (Concordia), reviewed 5,063 dental accident reports of 122,370 children under the age of 16. The predominant cause of injury was a "fall," with "playing" being the foremost activity mentioned and "ground" identified as the primary object of impact. The analysis of the involved objects showed that dental injuries occur most frequently with scooters, bicycles, and stairs. In 2019, 8.14% of children aged one and insured by Concordia suffered a dental injury. By age 16, 58.8% of all children had experienced a dental injury. 0.72% had suffered a primary dentition crown fracture with pulp involvement. Regarding their permanent teeth, 0.21% suffered an avulsion, 0.84% another luxation injury, 0.65% a crown fracture with pulp involvement, and 0.16% a root fracture. A significant increase in injuries per day was observed after the summer holidays. On weekends, there were 28% fewer injuries per day on average than on weekdays. Despite differences among the cantons, the dataset can be considered to be representative for Switzerland. Accident descriptions were often too brief for detailed prevention strategies. Detailed accident information is essential for effective structural measures, which are more effective than promoting behavioural changes. A detailed recording could also be used to draw up a list of the objects frequently involved in accidents. An updated insurance form with an improved nomenclature, the option of digital submission, photo uploads and AI-supported data recording could greatly improve the quality and interpretability of injury data.

A letter to editor addressing a methodological concern: A critical analysis of papers included in a systematic review on vertical root fractures

A letter to editor addressing a methodological concern: A critical analysis of papers included in a systematic review on vertical root fractures

Repairing the Irredeemable Fragment Reattachment of a Complicated Crown-root Fracture with Fiber Post

Coronal fracture of the anterior teeth is a commonly occurring dental trauma often seen in young individuals. Such fractures can be conservatively managed with fragment reattachment procedure when the fragment is available and preserved in correct storage media. Due to advancements in adhesive dentistry, fragment reattachment is a simple, esthetic and fast treatment option. This article reports a case of fragment reattachment of a complicated crown root fracture using fibre post as an intraradicular splint.

Topography of root-end surface after freehand and three-dimensional-guided apicoectomy procedure: A scanning electron microscope study.

Dentinal microcracks formed during apical resection may lead to increased susceptibility to root fracture and improper sealing of apical preparation that may negatively influence the outcome of endodontic microsurgery. This study was performed to analyze the root-end surface for dentinal microcracks using a scanning electron microscope (SEM) after resection with high-speed bur and trephine drill. Thirty extracted single-rooted maxillary premolar teeth were selected and randomly distributed into two groups (n = 15). Working length was established using a #15 K-type file. Canals were prepared with a rotary Ni-Ti system to size 30/0.06 using endomotor, irrigated with 3% sodium hypochlorite, dried with paper points, and obturated with gutta-percha cones using a single-cone technique. All samples were mounted on preformed molds and poured using a mixture of sawdust and gypsum. In Group A; tungsten carbide bur was used to perform a freehand apicoectomy. In Group B; a trephine drill was used with a three-dimensional guide to perform 3 mm of root resection. Apicoectomy was performed in both groups under a dental operating microscope. Resected root ends were inspected for microcracks using SEM. The Shapiro-Wilk and Mann-Whitney U-test were used for statistical analysis. Microcracks were observed in all samples in both study groups. Trephine drill produced more microcracks on the resected root surface compared to the use of high-speed tungsten carbide bur with a statistically significant difference (P < 0.05). The trephine drill used during targeted endodontic microsurgery produced more microcracks on the resected root dentine surface compared to the high-speed tungsten carbide bur used during freehand apicoectomy.

Can the Remaining Coronal Tooth Structure Influence the Mechanical Behavior of Nonpost Full Crowns?

This study investigated the impact of the remaining coronal tooth structure on the mechanical behavior of nonpost (NP) full crowns on endodontically treated maxillary central incisors. Forty bovine incisors with NP and 2-mm of ferrule were divided into four groups based on the remaining structure: complete 2-mm ferrule (NP-2), absence of mesial and distal ferrule effect (NP-BL), absence of buccal and lingual ferrule effect (NP-MD), and no ferrule (NP-0). The specimens underwent a stepwise stress fatigue test until fracture occurred, and stress distribution was analyzed using in silico finite element analysis (FEA). Additionally, groups with endodontic posts (P) were simulated in the FEA. The results showed that the survival rates varied among the different groups under oblique loading. The NP-2 group exhibited the highest survival rate, with all samples enduring loads up to 200 N and some surviving up to 520 N. The NP-MD and NP-BL groups had lower survival rates, while the NP-0 group had the poorest survival rate. The predominant failure mode was a nonrepairable root fracture. FEA results indicated no significant difference between groups with and without posts. NP intraradicular restorations on nonweakened roots with a minimum height of 2mm and partial or total ferrule thickness of 1mm offer a promising treatment option. A complete 2-mm ferrule was found to be the most favorable configuration for NP full crowns. However, maintaining the remaining tissue is crucial, as both combinations with preserved ferrule effect exhibited superior behavior in terms of fatigue and fracture load compared to the group with no ferrule. These findings contribute to understanding the mechanical considerations for NP full crowns and provide insights into treatment planning and design choices in restorative dentistry.

RESTORATION OF CORONAL PART IN CHEWING TEETH WITH SIGNIFICANT LOSS OF HARD TISSUES BY POST AND CORE CROWN

The purpose of this study was to improve the quality of orthopedic treatment of hard dental tissues of chewing teeth destroyed below the level of the gums by a post and core crown using ashless modeling plastics.&#x0D; We examined 30 patients with severe destruction of the hard tissues of the crown portion of the teeth (IROPZ more than 80%) and concurrent periodontal diseases. A retrospective analysis revealed that teeth with deep subgingival defects restored by casts functioned as follows: for up to 1 year in 17 cases (14.2%), from 1 to 3 years in 36 cases (30.0%), from 3 to 5 years in 43 cases (35.8%), and for more than 5 years in 24 cases (20.0%).&#x0D; The results of a comparative evaluation of the effectiveness of tooth restoration with subgingival defects using ashless acrylic plastic "Modeplast" as a modeling material demonstrated the highest quality of such inserts, with most observed cases showing no signs of secondary caries. Complications, such as the dislodgement of metal inserts, were noted in 6.7% of cases, violation of marginal fit in 4.5%, and partial decementation of the structure in 8.3%. Incorrect positioning and suboptimal pin dimensions of the post and core crown occurred with approximately equal frequency: 3.5% and 3.2%, respectively. Destruction of the hard tissues of the tooth and caries relapse during restoration with metal inserts were noted in 13.3% and 29.1% of cases, respectively. Typical complications leading to tooth extraction included tooth root fractures (13.3%).&#x0D; The developed method of manufacturing post and core crowns using ashless acrylic plastic "Modeplast" at the modeling stage enables to gently remove tooth tissues and atraumatic fit of the post to the gums, prevents the accumulation of dental plaque and does not have a destructive effect on periodontal tissues.

Comparative analysis of stress distribution in residual roots with different canal morphologies: evaluating CAD/CAM glass fiber and other post-core materials

BackgroundThe selection of post-core material holds significant importance in endodontically treated teeth, influencing stress distribution in the dental structure after restoration. The use of computer-aided design/computer-aided manufacturing (CAD/CAM) glass fiber post-core possesses a better adaptation for different root canal morphologies, but whether this results in a more favorable stress distribution has not been clearly established.Materials and methodsThis study employed finite element analysis to establish three models of post-core crown restoration with normal, oversized, and dumbbell-shaped root canals. The three models were restored using three different materials: CAD/CAM glass fiber post-core (CGF), prefabricated glass fiber post and resin core (PGF), and cobalt-chromium integrated metal post-core (Co-Cr), followed by zirconia crown restoration. A static load was applied and the maximum equivalent von Mises stress, maximum principal stress, stress distribution plots, and the peak of maximum displacement were calculated for dentin, post-core, crown, and the cement acting as the interface between the post-core and the dentin.ResultsIn dentin of three different root canal morphology, it was observed that PGF exhibited the lowest von Mises stresses, while Co-Cr exhibited the highest ones under a static load. CGF showed similar stress distribution to that of Co-Cr, but the stresses were more homogeneous and concentrated apically. In oversized and dumbbell-shaped root canal remnants, the equivalent von Mises stress in the cement layer using CGF was significantly lower than that of PGF.ConclusionsIn oversized root canals and dumbbell-shaped root canals, CGF has shown good performance for restoration of endodontically treated teeth.Clinical relevanceThis study provides a theoretical basis for clinicians to select post-core materials for residual roots with different root canal morphologies and should help to reduce the occurrence of complications such as root fracture and post-core debonding.