Modern Endodontic Surgery Concepts and Practice: A Review

The Washout Resistance of Bioactive Root-End Filling Materials

Fast-setting bioactive cements were developed for the convenience of retrograde fillings during endodontic microsurgery. This in vitro study aimed to investigate the effect of irrigation on the washout of relatively fast-setting materials (Biodentine, EndoCem Zr, and MTA HP) in comparison with MTA Angelus White and IRM in an apicectomy model. Washout resistance was assessed using artificial root ends. A total of 150 samples (30 for each material) were tested. All samples were photographed using a microscope, and half of them were also scanned. The samples were irrigated and immersed in saline for 15 min. Then the models were evaluated. Rinsing and immersing the samples immediately after root-end filling and after 3 min did not disintegrate the fillings made of all tested materials except Biodentine. Root-end fillings made of Biodentine suffered significant damage both when rinsing was performed immediately and 3 min after the filling. Quantitative assessment of washed material resulted in a slight loss of IRM, EndoCem MTA Zr, and MTA HP. MTA Angelus White showed a slightly greater washout. Rinsing and immersion of Biodentine restorations resulted in their significant destruction. Under the conditions of the current study, the evaluated materials, excluding Biodentine, showed good or relatively good washout resistance.

The implication of oversampling on the effectiveness of force signals in the fault detection of endodontic instruments during RCT

This work provides an innovative endodontic instrument fault detection methodology during root canal treatment (RCT). Sometimes, an endodontic instrument is prone to fracture from the tip, for causes uncertain the dentist's control. A comprehensive assessment and decision support system for an endodontist may avoid several breakages. This research proposes a machine learning and artificial intelligence-based approach that can help to diagnose instrument health. During the RCT, force signals are recorded using a dynamometer. From the acquired signals, statistical features are extracted. Because there are fewer instances of the minority class (i.e. faulty/moderate class), oversampling of datasets is required to avoid bias and overfitting. Therefore, the synthetic minority oversampling technique (SMOTE) is employed to increase the minority class. Further, evaluating the performance using the machine learning techniques, namely Gaussian Naïve Bayes (GNB), quadratic support vector machine (QSVM), fine k-nearest neighbor (FKNN), and ensemble bagged tree (EBT). The EBT model provides excellent performance relative to the GNB, QSVM, and FKNN. Machine learning (ML) algorithms can accurately detect endodontic instruments' faults by monitoring the force signals. The EBT and FKNN classifier is trained exceptionally well with an area under curve values of 1.0 and 0.99 and prediction accuracy of 98.95 and 97.56%, respectively. ML can potentially enhance clinical outcomes, boost learning, decrease process malfunctions, increase treatment efficacy, and enhance instrument performance, contributing to superior RCT processes. This work uses ML methodologies for fault detection of endodontic instruments, providing practitioners with an adequate decision support system.

Endodontic Microsurgery on a Persistent Periapical Lesion

Extrusion of root filling material had been shown to reduce the success of endodontic treatment. This case report describes the management of a patient who reported prolonged, persistent, and increasing pain on an upper root filled central incisor with extruded root filling material. A 28-year-old female patient came with the chief complaint of pain and tenderness on the upper left central incisor. The pain was mostly triggered by mastication. Upon examination and investigation, the tooth of concern was tooth 21 which was a root treated many years ago. It appeared to have tenderness on percussion and palpation. Non-surgical root canal retreatment was completed on tooth 21. However, the patient complained of the same pain while biting even after six months post-obturation. Therefore, endodontic microsurgery was performed to remove the root filling material that was extruded and to enucleate the granulomatous lesion around the periapical region of tooth 21. After enucleation, apical root end resection was performed. Postoperatively, the patient reported comfort and no pain and was able to resume her daily activities. At six months of review, the radiograph showed evidence of complete healing. This case report captured the importance of endodontic microsurgery as a viable treatment option where nonsurgical root canal retreatment failed to relieve the patient's symptoms.

Evaluating the efficacy of endodontic microsurgery for teeth with an undeveloped root apex and periapical periodontitis after nonsurgical treatment failure

AIM

To determine the efficacy of endodontic microsurgery for teeth with an undeveloped root apex and periapical periodontitis caused by an abnormal central cusp fracture after failed nonsurgical treatment.

METHODOLOGY

Eighty teeth in 78 patients were subjected to endodontic microsurgery. All patients were clinically and radiologically examined 1 year postoperatively. The data were statistically analyzed using SPSS 27.0 software.

RESULTS

Of the 80 teeth in 78 patients, periapical lesions had disappeared in 77 teeth at 1-year postoperative follow-up, with a success rate of approximately 96.3% (77/80). The efficacy of endodontic microsurgery was not affected by sex, age, extent of periapical lesions, and presence of the sinus tract. Between-group differences were not statistically significant (P > 0.05).

CONCLUSIONS

Endodontic microsurgery can be an effective alternative treatment option for teeth with an undeveloped root apex and periapical periodontitis caused by an abnormal central cusp fracture after nonsurgical treatment failure.

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.

Effect of field of view and voxel size on CBCT-based accuracy of dynamic navigation in endodontic microsurgery: an in vitro study

INTRODUCTION

This study aimed to evaluate the influence of field of view (FOV) and voxel size on the accuracy of dynamic navigation (DN)-assisted endodontic microsurgery (EMS).

METHODS

Nine sets of maxillary and mandibular three-dimensional-printed jaw models composed of 180 teeth were divided into nine groups with different FOVs (80 × 80 mm, 60 × 60 mm, and 40 × 40 mm) and voxel sizes (0.3, 0.16, and 0.08 mm). The endodontic DN system was used to plan and execute the EMS. The accuracy of the DN-EMS was represented by the platform deviation, end deviation, angular deviation, resection angle, and resection length deviation. Statistical analyses were performed using SPSS 24.0, and the significance level was set at p < 0.05.

RESULTS

The average platform, end, angular, resection angle, and resection length deviation were 0.69 ± 0.31 mm, 0.93 ± 0.44 mm, 3.47 ± 1.80°, 2.35 ± 1.76°, and 0.41 ± 0.29 mm, respectively. No statistically significant differences in accuracy were observed between the nine FOV and voxel size groups.

CONCLUSION

FOV and voxel size did not appear to play an important role in the accuracy of DN-EMS. Considering the image quality and radiation dose, it is reasonable to select a limited FOV (such as 40 × 40 mm and 60 × 60 mm) to cover only the registration device, involved teeth, and periapical lesion. The voxel size should be selected according to the required resolution and CBCT units.

A Cadaver-based comparison of Sleeve-Guided Implant-drill and Dynamic Navigation Osteotomy and Root-end Resections

INTRODUCTION

This study compared the accuracy and efficiency of fully guided static and dynamic computer-assisted surgical navigation techniques for osteotomy and root-end resection (RER).

METHODS

Fifty roots from cadaver heads were divided into two groups: fully guided static computer-assisted endodontic microsurgery (FG sCAEMS) and dynamic computer-assisted endodontic microsurgery (dCAEMS) (all, n = 25). CBCT scans were taken pre- and postoperatively. The osteotomy and RER were planned virtually in the preoperative CBCT scan and guided using 3D-printed surgical guides in the FG sCAEMS and 3D-dynamic navigation system in the dCAEMS. The 2D and 3D deviations and angular deflection (AD) were calculated. The osteotomy volume, resected root length, and resection angle were measured. The osteotomy and RER time and the number of procedural mishaps were recorded.

RESULTS

FG sCAEMS was as accurate as dCAEMS, with no difference in the 2D and 3D deviation values or AD (p >.05). The osteotomy and RER time were shortened using FG sCAEMS (p <.05). The FG sCAEMS showed a greater number of incomplete RERs than dCAEMS. Osteotomy volume, RER angle, and root length resected were similar in both groups (p >.05). FG sCAEMS and dCAEMS were feasible for osteotomy and RER.

CONCLUSIONS

Within the limitations of this cadaver-based study, FG sCAEMS was as accurate as dCAEMS. Both FG sCAEMS and dCAEMS were time-efficient for osteotomy and RER, but FG sCAEMS required less surgical time.

Application of Real-Time Augmented Reality-Guided Osteotomy and Apex Location in Endodontic Microsurgery: A Surgical Simulation Study Based on 3D-Printed Alveolar Bone Model

INTRODUCTION

Augmented reality (AR) is a novel visualization technique in which pre-generated virtual 3D content is superimposed on surgical sites. This study aimed to validate the viability of AR-guided endodontic microsurgery (ARG) and compare the changes in objective and subjective outcomes of surgical simulation using ARG and freehand endodontic microsurgery (FH) on customized 3D-printed models.

METHODS

We created and printed a customized 3D alveolar bone model with artificial periapical lesions (APLs) based on cone-beam computed tomography (CBCT). Eight models with 96 APLs were equally divided into ARG and FH groups. We planned surgical trajectories on re-scanned printed models. Four inexperienced residents (IRs) performed ARG and FH on the models and completed pre-and intraoperative confidence questionnaires for the subjective outcome. Postoperative CBCT scans of the models were reconstructed and analyzed, and all procedures were timed. We used pairwise Wilcoxon rank sum tests to compare objective outcomes. Kruskal-Wallis tests and post-hoc pairwise Wilcoxon rank sum tests were used to compare subjective outcomes.

RESULTS

Compared to the FH group, the ARG group significantly reduced deviation of the volume of bone removal, root-end resection, and deviation of bevel angle, with improved confidence of the IRs (P < 0.05); it also significantly increased surgical time and volume of unremoved APL (P < 0.05).

CONCLUSIONS

We customized an APL model through 3D printing and developed and validated a low-cost AR application framework, based on free AR software, for endodontic microsurgery. ARG allowed IRs to perform more conservative and precise surgical procedures with enhanced confidence.

Clinical Effect Evaluation of Concentrated Growth Factor in Endodontic Microsurgery: A Cross-Sectional Study

INTRODUCTION

Concentrated growth factor (CGF) is the third-generation platelet concentrate product. This study aimed to evaluate whether the use of CGF during endodontic microsurgery had a positive influence on surgical outcomes.

METHODS

Fifty-four patients who underwent endodontic microsurgery from January 2017 to November 2021 were enrolled. They were assigned to the CGF and the control group according to whether CGF was used during the surgery and followed up at 6, 12, and 18 months post-surgery. Preoperative classification of the cases and follow-up radiographic outcomes were based on Kim's classification and Molven's criteria respectively and evaluated by two calibrated endodontists. Student t-test and Chi-square test were used to assess the baseline of two groups. Rank sum test was used to determine whether CGF had an impact on the surgical outcome.

RESULTS

Thirty-one patients (41 periapical lesion sites) were included in the CGF group, and twenty-three patients (26 periapical lesion sites) were included in the control group. The overall success rate of endodontic microsurgery was above 90%. The baseline of the two groups had no difference (P<0.05). In the CGF group, the success rate was always 100% in three follow-ups, while the success rate was 84.2%, 92.8%, and 90% respectively in the control group. The success rate between the CGF group and the control group was statistically significant in all three follow-up points (P<0.05).

CONCLUSIONS

The application of CGF during endodontic microsurgery might have a positive influence on surgical outcomes, thus, its prognosis. However, higher-grade evidence is needed to demonstrate its role.

Analysis of the Accuracy of a Dynamic Navigation System in Endodontic Microsurgery: A Prospective Case Series Study: Accuracy of DNS in EMS

OBJECTIVES

To evaluate the accuracy of a dynamic navigation system (DNS) for guided osteotomy and root-end resection during endodontic microsurgery (EMS) and assess its prognosis.

METHODS

Nine patients who met inclusion criteria underwent DNS-guided EMS. Osteotomy and root-end resection were performed with assistance of DNS (DHC-ENDO1, DCARER Medical Technology, Suzhou, China). The preoperative virtually planned path and postoperative cone-beam computed tomography images were superimposed using DNS software. Accuracy was assessed based on deviations in the platform, apex, and angle of the osteotomy, as well as in the length and angle of the root-end resection. Follow-up evaluations were performed after at least a year postoperatively.

RESULTS

Among the nine patients (11 teeth with 12 roots), the mean platform, apex, and angular deviation of the osteotomy were 1.05 mm, 1.2 mm, and 6.24°, respectively. The mean length and angle deviation of the root-end resection were 0.46 mm and 4.9°, respectively. Significant differences were observed according to tooth position. The platform and apex deviated significantly less in the posterior than in the anterior teeth (p < .05). No significant differences were observed according to arch type, side, and depth of the surgical path (p > .05). Eight patients were evaluated after at least a year postoperatively; clinical and radiographic evaluation revealed a 90% success rate (9/10 teeth).

CONCLUSIONS

This study demonstrated high accuracy of DNS in EMS. Furthermore, DNS-guided EMS had a success rate similar to that of freehand EMS over a short-term follow-up. Further study with a larger sample size is necessary.

CLINICAL SIGNIFICANCE

The present novel DNS technology is a viable method for guided osteotomy and root-end resection in EMS.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR2100042312.

Utility of biphasic calcium phosphate cement as a seal for root-end filling

The recently developed biphasic calcium phosphate cement (BCPC) consists of α-tricalcium phosphate-tetracalcium phosphate as the solid phase and calcium phosphate solution as the liquid phase. BCPC powder is composed of a single solid solution with a monomodal size distribution. Here, we used a bacterial leakage model to examine the utility of BCPC as a seal for root-end filling. We prepared large (median particle size=9.96 µm; BCPC-L) and small (median particle size=4.84 µm; BCPC-S) BCPC powders. In total, 45 single-rooted teeth were instrumented, resected at the root-end, and retrofilled with experimental materials. Mineral trioxide aggregate (MTA) was used as the control. After visual confirmation of BCPC powder size and retrofilling quality by microscopy, bacterial leakage tests were conducted using Enterococcus faecalis. The bacterial leakage tests did not reveal any significant differences between BCPC-S and MTA. Our findings suggest that BCPC-S is useful for root-end filling.

Histological Evaluation of Root Canals by Performing a New Cleaning Protocol “RUA” in Endodontic Surgery

Aim: To enhance cleaning during retro-preparation in endodontic microsurgery. Materials and Methods: Forty mandibular premolars were instrumented, filled with a single cone technique, and then retro-preparation was performed and assigned to experiment A. In group A1, the cavity created by the retro preparation was cleansed with 2 mL of normal sterile saline. In group A2, the retro cavity was cleaned with 2 mL of sterile saline after the retro preparation. All the irrigation solutions mentioned above were delivered using an endodontic needle with a lateral vent and a gauge of 30. Subsequently, in group A2, 17% EDTA gel and 5.25% gel were inserted into the cavity and activated using ultrasonic tips. After the irrigation protocols, the specimens were decalcified for histological evaluation. Results: In the experiment, the amount of hard tissue debris was significantly greater in group A1 compared to group A2 (p < 0.05). Conclusions: The samples in group A2, where the new protocol was performed, showed statistically significant results.

Factors that influence the outcomes of surgical endodontic treatment

Surgical endodontic treatment encompasses a broad spectrum of procedures, amongst which root-end cavity preparation and filling, retrograde root canal treatment and through-and-through endodontic surgery, may be classified under the umbrella term 'Root-end surgery'. This narrative review considers the available data on periapical healing, soft tissue healing, tooth survival and oral health-related quality of life (OHRQoL), following root-end surgery and the factors that affect its outcomes. The pooled periapical healed rate for the studies published up to 2021 was 69% (95% CI: 65%, 73%) but increased to 76% (95% CI: 66%, 86%) when only data from the 2020's studies were analysed. The prognostic factors consistently reported for periapical healing have included: pre-operative periapical lesion with complete loss of buccal plate, quality of root-end preparation, remaining thickness of apical root dentine and restorative status. Soft tissue healing of the reflected flap was found to have a positive association with periapical healing. The survival rates following root-end surgery range from 48% to 93%, with failure of periapical healing associated with root and crown fracture, being the predominant reasons for tooth extraction. The factors influencing impact of root-end surgery on patients' quality of life could not be adequately evaluated due to design flaws in the available studies. In conclusion, if root canal treatment failure due to leakage through cracks, fractures or restoration margin are excluded, the remaining cases may represent localized residual infection and inflammation at the periapex that should be amenable to predictable management with the aid of modern root-end surgery.

Comparison of Static and Dynamic Navigation in Root End Resection Performed by Experienced and Inexperienced Operators: An In Vitro Study

INTRODUCTION

This study aimed to compare the effects of static navigation (SN), a dynamic navigation system (DNS), and the freehand (FH) technique in root end resection and the differences between these effects according to the level of experience of the operator.

METHODS

Maxillary models reconstructed with Mimics software (Materialise, Leuven, Belgium) were 3-dimensionally printed and divided according to the experimental technique (FH, SN, or DNS) and the operator (experienced or inexperienced). SN was designed using 3-matic Medical software (Materialise) and printed, and a surgical approach plan for DNS was established and performed using DCARER (Suzhou, China) software. The accuracy, efficiency, and safety of the resections were assayed.

RESULTS

The length, angle, volume, and depth deviations of the root end resections were significantly lower in the SN and DNS group compared with the FH group. SN significantly improved the efficiency of both operators, whereas DNS only improved the efficiency of the inexperienced operator. No difference between the SN and DNS groups was found, except for the time required for the surgery. No mishaps occurred during surgery in the SN or DNS group. The number of mishaps with the FH technique when used by the inexperienced operator was significantly higher than that registered for the rest of the groups. No interaction effect between technique and operator experience level was detected.

CONCLUSIONS

Regardless of operator experience, both SN and DNS could improve the accuracy and safety of root end resection. SN significantly improved the chairside efficiency of both operators, whereas DNS was more helpful for the inexperienced operator.

Comparison of a Novel Static Computer-aided Surgical and Freehand Techniques for Osteotomy and Root-end Resection

INTRODUCTION

This study compared the accuracy and efficiency of a novel static computer-aided surgical technique using a 3-dimensional (3D)-printed surgical guide (3D-SG) with a fully guided drill protocol (3D-SG FG) to the freehand (FH) osteotomy and root-end resection (RER).

METHODS

Forty-six roots from 2 cadaver heads were divided into 2 groups: 3D-SG FG (n = 23) and FH (n = 23). Cone-beam computed tomographic scans were taken preoperatively and postoperatively. The endodontic microsurgery was planned in Blue Sky Bio software, and the 3D-SG was designed and 3D printed. The osteotomy and RER were conducted using a guided twist drill diameter of 2 mm and an ascending tapered drill with diameters of 2.8/3.2, 3.2/3.6, 3.8/4.2, and 4.2 mm with respective guided drill guides. Two-dimensional and three-dimensional virtual deviations and angular deflection were calculated. Linear osteotomy measures and root resection angle were obtained. The osteotomy and RER time and the number of mishaps were recorded.

RESULTS

Two-dimensional and three-dimensional accuracy deviations and angular deflection were lower in the 3D-SG FG protocol than in the FH technique (P < .05). The height, length, and depth of the osteotomy and root resection angle were less in the 3D-SG FG protocol than in the FH technique (P < .05). The osteotomy and RER time with the 3D-SG FG protocol were less than the FH method (P < .05).

CONCLUSIONS

Within the limitations of this cadaver-based study using denuded maxillary and mandibular jaws, 3D-SG FG protocol showed higher accuracy than FH osteotomy and RER. Moreover, the 3D-SG FG drill protocol significantly reduced the surgical time.

Outcomes of endodontic microsurgery using different calcium silicate-based retrograde filling materials: a cohort retrospective cone-beam computed tomographic analysis

PURPOSE

To evaluate the outcomes of endodontic microsurgery (EMS) using mineral trioxide aggregate (MTA; Dentsply Sirona, Charlotte, NC, USA), EndoSequence root repair material (RRM putty; Brasseler, Savannah, GA), and injectable Bioceramic (BC) sealer (Brasseler USA) followed by the application of RRM putty (lid technique) as root-end filling materials.

METHODS

One hundred and ten patients who underwent EMS between 2016 and 2020 at King Abdulaziz University Dental Hospital were recruited for clinical and radiographic follow-up after a minimum of 1 year. Radiographic assessment was performed using periapical radiographs (PAs) and cone-beam computed tomography (CBCT). Volumetric analysis of periapical radiolucencies (PARLs) was performed using Amira software.

RESULTS

Seventy-nine patients (103 teeth: MTA group, n = 28; RRM putty, n = 41; lid technique, n = 34), attended the follow-up visit, with an average follow-up period of 24 months (recall rate = 74.5%). Of the 103 teeth, 40 were anteriors, 24 were premolars, and 39 were molars. All three groups of retrograde filling materials (MTA, RRM putty, and lid technique) showed high success rates on both PA (85.7, 85.4, 94.1%, respectively) and CBCT imaging (67.9, 75.6, 88.2%, respectively), without any significant difference among the success rates of different materials. Overall, a slight agreement was noted between the PA and CBCT outcomes, with a statistically significant difference (P = 0.029). None of the patient-, tooth-, or treatment-related factors significantly influenced the outcomes of EMS. Adequate density of root canal filling material was significantly associated with a high percentage of completely healed cases on CBCT (P = 0.044). PARL volumes were reduced significantly over 1-4 years follow-up after EMS (P < 0.001) CONCLUSIONS: EMS showed high success rates on both PA and CBCT when MTA, RRM putty or lid technique were used as retrograde filling materials. CBCT imaging is more precise than PA in detecting the healing outcomes of EMS.

Surgical endodontic treatment of maxillary incisors: Case report

This study aims to highlight the possibility of an effective endodontic surgical surgery when nonsurgical treatment of the right maxillary anterior teeth has failed. One year after the apicoectomy, the periapical lesion has completely healed, new bone has formed, and the patient is symptom-free.

Surgical Management of Radicular Cyst With the Application of a Natural Platelet Concentrate: A Case Report

Traumatic dental injuries usually involve the dentoalveolar region, and they readily affect the teeth and their surrounding soft and hard tissues. The common sequelae of traumatic dental injuries lead to pulpal necrosis and apical periodontitis along with cystic changes. The current case report describes the surgical management of a radicular cyst in the periapical region of maxillary incisors and highlights the efficacy of natural platelet concentrate [platelet-rich fibrin (PRF)] used for postoperative healing. A 38-year-old male patient presented to the department with pain and mild swelling in the upper front tooth region. On radiographic examination, a radiolucent periapical lesion was evident in relation to the right maxillary central and lateral incisor. In the maxillary anterior region, root canal therapy was performed, followed by periapical surgery and retrograde filling with mineral trioxide aggregate (MTA), and PRF was placed in the surgical site to initiate the healing at a faster rate. The patient was recalled for follow-ups after 12 weeks, 24 weeks, and 36 weeks; he was found to be asymptomatic, and significant periapical healing was observed in the radiograph with almost adequate bone formation.

Evaluation of a dynamic navigation system for endodontic microsurgery: study protocol for a randomised controlled trial

INTRODUCTION

Endodontic microsurgery is a very important technique for preserving the natural teeth. The outcomes of endodontic microsurgery largely depend on the skill and experience of the operators, especially for cases in which the apices are located far away from the labial/buccal cortical bone. A dynamic navigation system (DNS) could provide a more accurate and efficient way to carry out endodontic microsurgery. This study is devoted to comparing the clinical outcomes of the DNS technique with those of the freehand technique.

METHODS AND ANALYSIS

Sixteen patients will be randomly assigned to one of two groups. For the experimental group, the osteotomy and root-end resection will be performed under the guidance of dynamic navigation. For the control group, these procedures will be performed freehand by an endodontist. The required time to perform these procedures will be used to evaluate the efficiency of the DNS technique. A Visual Analogue Scale will be used to evaluate pain at 1, 3 and 7 days after endodontic microsurgery. Preoperative and postoperative cone beam CT scans will be obtained to evaluate the accuracy of the DNS technique. The global coronal deviations, the apical deviations and the angular deflection will be measured. The root-end resection length deviation, the root-end resection angle deviations, the extent of the osteotomy and the volume change of the buccal cortical bone will also be measured. Periapical radiographs will be obtained to evaluate the outcome at 1 year after microsurgery. The time to execute the study, including follow-ups, will last from 1 June 2022 to 31 December 2025.

ETHICS AND DISSEMINATION

The present study has received approval from the Ethics Committee of Peking University School and Hospital of Stomatology. The results will be disseminated through scientific journals.

TRIAL REGISTRATION NUMBER

ChiCTR2200059389.

The effect of imaging modality on the evaluation of the outcome of endodontic surgery

OBJECTIVES

The aim of this study was to assess the effect of the imaging modality on the evaluation of the outcome of modern surgical endodontic treatments, based on a systematic review of the literature.

METHODS

Strict inclusion criteria were adopted in order to identify studies that assessed the outcome of surgical endodontic treatments. Treatment success rates were pooled. The effect of the imaging modality used for the outcome assessment, and the methodological quality of the studies (based on the risk of bias (ROB)), were evaluated.

RESULTS

Nineteen articles were included. The success rates assessed by periapical (PA) radiography were significantly higher than when cases were evaluated by cone beam computed tomography (CBCT; 90 and 35% respectively). This difference was mainly due to a significant proportion of cases that were assessed by CBCT as uncertain healing (48%) compared to only 4% using PA. The success rates ranged between 86 and 92% in low ROB studies, and between 19-100% in high ROB studies.

CONCLUSIONS

Outcome assessment based on CBCT may lead to significantly lower estimates of rate of success, and higher rates of uncertain healing, thus presenting a dilemma in the decision-making following surgical endodontic treatment. The success rates of studies with lower methodological quality are more variable than for high quality studies.

Comparative evaluation of push-out bond strength of three retrograde filling materials in teeth with root apices resected at 90°: Mineral trioxide aggregate Angelus, Zirconomer, and Bioactive bone cement

Background

Surgical endodontic dissatisfaction is frequently caused by an inadequate seal at the apex. The retrograde filling material utilized should prevent any contaminants from seeping into the periradicular tissue.

Aim

(1) To evaluate push-out bond strength of mineral trioxide aggregate (MTA) Angelus, Zirconomer, and Bioactive bone cement as root-end filling material, (2) To compare push-out bond strength of three different retrograde filling materials with a universal testing machine.

Materials and Methods

At the cementoenamel junction, 36 removed upper anterior teeth were sliced horizontally. The samples were resected 3 mm at the apical end at a 90° angle along the long axis of the tooth, following the standard protocols. With an ultrasonic tip S12 90ND, a 3 mm root-end cavity was made. The teeth were then divided into three groups at random: Group 1: MTA Angelus, Group 2: Zirconomer, and Group 3: Bioactive bone cement. With the help of small pluggers, each material was compacted in the root-end cavity. Acrylic resin was used to embed the specimens. Each specimen's apical section was sliced into 2-mm thick slices perpendicular to the long axis. A universal testing equipment was used to apply a compressive push-out load, and the push-out bond strength was determined in megapascals.

Results

Zirconomer showed higher push-out bond strength when placed in the retrograde cavity preparation, followed by MTA Angelus and then Bioactive bone cement.

Conclusion

Zirconomer showed superior resistance to dislodgment when compared to MTA Angelus, followed by Bioactive bone cement.

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.

Healing of Unilateral Maxillary Sinusitis by Endodontic and Periodontal Treatment of Maxillary Teeth

Inflammatory conditions of dental origin may spread to the bone tissue, causing its destruction, and to anatomical structures located in the vicinity of the tooth affected with inflammation. Maxillary premolars and molars may develop inflammatory lesions of the Schneiderian membrane and lead to tooth-borne lesions in the maxillary sinuses. Unilateral inflammation of the maxillary sinuses should be diagnosed and treated. The aim of this study was to determine whether and after what time from the applied endodontic or nonsurgical periodontal treatment the inflammation in the maxillary sinus was diminished (assessed by the decrease in the Schneiderian membrane hypertrophy). A retrospective study was performed to analyze the records of endodontically, periodontally, or endodontically-periodontally treated patients with unilateral inflammation of the maxillary sinuses along with diagnostic Cone Beam Computed Tomography. The method for determination of the inflammation was measurements registered in millimeters in Carestream software. The analysis included the situation before treatment and 3 months, 6 months, and 12 months after completion of the treatment. Regardless of the origin of the maxillary sinus lesion, healing of inflammation of the sinus has been reported after the implementation of causative treatment of the maxillary tooth. Dental treatment reduces the need to implement conservative or surgical ENT treatment.

Intentional Replantation as a Starting Approach for a Multidisciplinary Treatment of a Mandibular Second Molar: A Case Report

Intentional replantation (IR) may offer a solution for persistent periapical lesions associated with endodontically treated teeth. A 35-year-old male patient presented with pain associated with the left mandibular second molar and hypoesthesia. Upon clinical examination, increased probing pocket depth in the mid-buccal surface was detected. Cone beam computed tomography revealed a previous non-surgical root canal treatment, with root canal filling material extrusion adjacent to the inferior alveolar nerve, a fractured instrument in the mesial root, and a large periapical radiolucency involving both teeth 37 and 36. A diagnosis of symptomatic post-treatment apical periodontitis was established. After discussing treatment options with the patient, an IR of tooth 37 was performed. Extra-oral procedures were completed in 17 min. At 9 months, hypoesthesia resolution was reported, and apical healing was radiographically observed. After 2.5 years, the replanted tooth showed extensive root resorption. An extraction with alveolar ridge preservation, using leukocyte-platelet rich fibrin (L-PRF), was performed. Six months after tooth extraction and regeneration, implant placement surgery was carried out. IR presents a valid treatment modality for the management of post-treatment apical periodontitis. When orthograde retreatment or apical microsurgery prove to be unfeasible, IR is a unique procedure with the potential to promote tooth preservation in properly selected cases. Although unsuccessful after 2.5 years, the IR of tooth 37 allowed for bone regeneration, the maintenance of tooth 36 vitality, and hypoesthesia resolution.

Sealing Ability of Bioactive Root-End Filling Materials in Retro Cavities Prepared with Er,Cr:YSGG Laser and Ultrasonic Techniques

The aim of this in vitro study was to compare the apical sealing ability of total fill bioceramic root repair material (BC-RRM) and mineral trioxide aggregate (MTA), regarding the retrograde preparation technique used: ultrasonic or erbium, chromium: yttrium, scandium, gallium, or garnet (Er,Cr:YSGG) laser. The study sample consisted of 48 human single-rooted teeth. After root-end resection, the samples were divided into two groups, according to the retrograde preparation technique used: Group 1: ultrasonic; Group 2: Er,Cr:YSGG laser. In each group, half of the retrograde cavities were filled with BC-RRM, and the other half were filled with MTA. The specimens were mounted in tubes and sterilized in plasma. The root canals were inoculated with Enterococcus faecalis, and the tubes were filled with fetal bovine serum, leaving the apical part of the root in the serum. After 30 days, the canals were sampled and cultured, and the colony forming units (CFUs) were counted with the additional polymerase chain reaction (PCR analysis). There was no significant difference between ultrasonic groups and the Er,Cr:YSGG-MTA group, regarding the number of CFUs (p > 0.05). The Er,Cr:YSGG-BC-RRM group showed the highest number of remaining viable bacteria (p < 0.001). Both filling materials filled in ultrasonic preparations presented similar sealing abilities. The BC-RRM showed more leakage when used in retro cavities prepared with the Er,Cr:YSGG laser.

Comparison of the accuracy and efficiency of a 3D dynamic navigation system for osteotomy root-end resection performed by novice and experienced endodontists

AIM

To investigate whether the 3D-dynamic navigation system (3D-DNS) can improve experienced endodontists' (EEs') and novice endodontists' (NEs') accuracy and efficiency in osteotomy and root-end resection (RER) and to verify that the 3D-DNS enables NEs to perform osteotomy and RER as accurately and efficiently as EEs.

METHODS

Seventy-six roots in cadaver heads were randomly divided into four groups: 3D-DNS-NE, 3D-DNS-EE, Freehanded (FH)-NE, and FH-EE (all, n=19). CBCT scans were taken pre- and postoperatively. Osteotomy and RER were planned virtually in the X-guided software (X-Nav Technologies, Lansdale). Accuracy was calculated by measuring the 2D and 3D virtual deviations and angular deflection (AD) using superimposing software (X-Nav technologies). Efficiency was determined by time of operation and the number of mishaps.

RESULTS

Accuracy deviations were significantly less in the 3D-DNS-EE group than in the FH-EE group (p<.05). We found lessened 2D and 3D accuracy deviations comparing the 3D-DNS-NE group to the FH-NE group (p<.05). The time required for osteotomy and RER with the 3D-DNS was ∼ ½ of that required for the FH method for both EEs and NEs (p<.05). We found no difference in the number of mishaps between the 3D-DNS and FH groups for EEs and NEs (p>.05).

CONCLUSIONS

The 3D-DNS improved EEs' and NEs' accuracy and efficiency in osteotomy and RER. The NEs were as efficient as the EEs using 3D-DNS. Notably, the 3D-DNS improved the NEs' accuracy compared to FH method but the 3D-DNS did not enable the NEs to perform osteotomy and RER as accurately as the EEs.

Sealing Ability and Adaptability of Nano Mineral Trioxide Aggregate as a Root-End Filling Material

Aim: Comparison between Nano MTA & MTA as a root-end filling materials regarding adaptability and sealing ability. Materials and Methods: Forty extracted human maxillary incisors with straight roots were used. After root canals preparation and obturation, the apical 3 mm of each root was resected perpendicular to the long axis of the tooth. Root end cavities were prepared to a depth of 3mm parallel to the long axis of the tooth. The teeth were randomly divided into two main equal groups of 20 samples each according to the root-end filling material used either MTA or Nano MTA. Ten samples from each group were sectioned longitudinally into two equal halves to measure the sealing ability and another ten samples from each group were sectioned transversally to obtain 1 mm thick section to measure the adaptability of both materials. All samples were photographed under the SEM at three different magnifications (×1000). The gap thickness between the root end filling material and the retro cavity dentine walls were measured at seven selected points at the material-dentine interface in micrometers (µm). Results: Nano MTA and MTA showed no statistically significant difference in the gap thickness between dentin-material interface in both longitudinal and transverse sections. Regarding the sealing ability, the mean value in MTA was (3.27±0.77), while the mean in Nano-MTA was (3.15±0.71). Regarding the adaptability, the mean value in MTA was (2.46±0.60), while the mean in Nano-MTA was (2.05±0.712). Both materials showed good sealing ability and good adaptation to the dentinal wall. Conclusion: Nano MTA revealed good sealing ability and adaptability comparable to MTA when used as a retrograde filling material.

Management of type IIIb dens invaginatus using a combination of root canal treatment, intentional replantation, and surgical therapy: A case report

BACKGROUND

Type Ⅲb dens invaginatus (DI) with a lateral canal located at the mid-third of the root is rarely reported. Here, we report a rare case of type Ⅲb DI in the left upper anterior tooth with a lateral canal that led to persistent periodontitis.

CASE SUMMARY

A 15-year-old female patient presented with a chief complaint of pain associated with recurrent labial swelling in the area of the left anterior tooth. A diagnosis of type Ⅲb DI and chronic periodontitis was made. Intentional replantation was performed after conventional endodontic treatment failed. After 6 mo, the patient was asymptomatic, but a sinus tract was observed. Cone-beam computed tomography images showed bone loss in the mesial of the mid-root. Based on methylene blue staining and microscopy images, the lateral foramen located at the middle third of the root was surgically treated. After 3 years of follow-up, the clinical findings and radiographic assessment presented a favorable prognosis of bone healing without root absorption or ankylosis.

CONCLUSION

Type Ⅲb DI with a lateral canal can be successfully treated by root canal treatment, intentional replantation, and surgical therapy.

Present Status and Future Directions - Surgical Endodontics

Endodontic surgery encompasses several procedures for the treatment of teeth with a history of failed root canal treatment, such as root-end surgery, crown- and root resections, surgical perforation repair, and intentional replantation. Endodontic microsurgery is the evolution of the traditional apicoectomy techniques and incorporates high magnification, ultrasonic root-end preparation and root-end filling with biocompatible filling materials. Modern endodontic surgery uses the dental operating microscope, incorporates cone-beam computed tomography (CBCT) for preoperative diagnosis and treatment planning, and has adopted piezoelectric approaches to osteotomy and root manipulation. Crown- and root resection techniques have benefitted from the same technological advances. This review focuses on the current state of root-end surgery by comparing the techniques and materials applied during endodontic microsurgery to the most widely used earlier methods and materials. The most recent additions to the clinical protocol and technical improvements are discussed, and an outlook on future directions is given. While non-surgical retreatment remains the first choice to address most cases with a history of endodontic failure, modern endodontic microsurgery has become a predictable and minimally invasive alternative for the retention of natural teeth.

REAL-TIME 3D IMAGE-GUIDED NAVIGATION SYSTEM IN ENDODONTIC MICROSURGERY - A CADAVER STUDY

INTRODUCTION

This study evaluated the accuracy and efficiency of 3D Dynamic Navigation System (3D-DNS) to perform minimally invasive osteotomy (MIO) and root-end resection (RER) in endodontic microsurgery (EMS) and investigated the viability of root-end cavity preparation (RECP) and fill (REF) in MIO.

METHODS

We divided 48 tooth roots in cadaver heads into two groups: 3D-DNS (n = 24) and freehand (n = 24). Cone beam computed tomography (CBCT) scans were taken before and after surgery. First, we verified virtual 3D-DNS accuracy using three outcome measures: 2D and 3D virtual deviations and angular deflection (AD). Second, we investigated 3D-DNS's accuracy for performing MIO in two outcome measures: Osteotomy size and volume. Third, we determined the 3D-DNS accuracy for RER in three outcomes: Resected root length, root length after resection, and resection angle. We investigated the viability of RECP and REF and measured REF depth and volume, as well, recording procedural times and number of mishaps.

RESULTS

2D and 3D virtual deviations and AD were lower in the 3D-DNS than FH (p<.05). Osteotomy height, length, and volume were all reduced when using 3D-DNS (p < .05). The resection angle was lower for the 3D-DNS (p<.05). RECP and REF were completed in 100% of the roots. The REF depth achieved was ∼ 3mm. Osteotomy time, RER time, and total procedure time were all significantly shortened using 3D-DNS (p < .05).

CONCLUSIONS

3D-DNS enabled our surgeon to perform accurate and efficient EMS with minimally invasive osteotomy and RER. The surgeon was also able to conduct RECP with adequate REF in minimally invasive osteotomy performed using 3D-DNS guidance.

Platelet-rich fibrin/anorganic bovine bone mineral complex as grafting materials in endodontic microsurgery with a large lesion size: study protocol for a randomised controlled trial

INTRODUCTION

Endodontic microsurgery is a treatment of last resort for preserving natural teeth. According to radiographic evaluation, the percentage of complete healing after endodontic microsurgery is only 74.3%. The use of regenerative techniques in endodontic microsurgery for large lesions (>10 mm diameter) is therefore recommended. The most frequently used bone graft in endodontic microsurgery is anorganic bovine bone mineral (ABBM) but this only has an osteoconductive effect. Thus, when platelet-rich fibrin (PRF), a reservoir of growth factors, is used together with ABBM, it increases the regenerative effect. This study is devoted to comparing the clinical outcomes of PRF with/without ABBM as grafting biomaterials in endodontic microsurgery cases with large lesion size to provide some valuable reference data for dentists.

METHODS AND ANALYSIS

Sixteen patients who are in need of endodontic microsurgery will be recruited. The patients will be randomly assigned to one of two groups: an experimental group, treated with PRF/ABBM complex and collagen membrane, and a control group, treated with ABBM and collagen membrane. Clinical examination including percussion, mobility testing and presence/absence of sinus will be recorded at 7 days, and at 3, 6 and 12 months after endodontic microsurgery. A Visual Analogue Scale will be used by the patients to evaluate pain at 1, 3 and 7 days after endodontic microsurgery. Routine paralleling radiographs will be obtained before and at 3, 6 and 12 months follow-up after endodontic microsurgery. Cone-beam CT (CBCT) scans will be obtained at the 12-month follow-up. Bone formation will be evaluated according to CBCT and paralleling radiographs. The study execute time including follow-ups last from 1 June 2021 to 31 December 2024.

ETHICS AND DISSEMINATION

This study received approval from the Ethics Committee of Peking University School and Hospital of Stomatology. The results will be disseminated through scientific journals.

TRIAL REGISTRATION NUMBER

Research data will be registered with the International Clinical Trials Registry Platform (ICTRP), ID: ChiCTR2100046684.

A retrospective cohort study on outcome and interactions among prognostic factors of endodontic microsurgery

BACKGROUND/PURPOSE

Endodontic microsurgery (EMS) is a reliable treatment for teeth with non-healing apical periodontitis. This study evaluated the outcome of EMS with mineral trioxide aggregate as the retrograde filling material and identified potential prognostic factors associated with the EMS outcome.

METHODS

Consecutive clinical and radiographic records of EMS performed in a teaching hospital from 2013 to 2017 were reviewed. Cases of root fracture, cemental tear, re-surgery, and incomplete records were excluded. After selection, 268 EMS-treated teeth with the follow-up period more than one year were included. Surgical outcome as success or failure was evaluated according to Molven's criteria. For analysis of potential prognostic factors, multivariate logistic regression was performed followed by bivariate chi-square tests. Stratified analysis was performed to understand the interactions between two prognostic factors.

RESULTS

The overall EMS success rate was 89.9% in this study. Tooth type (anteriors vs. molars, odds ratio (OR) = 6.83, P = 0.001, anteriors vs. premolars, OR = 4.27, P = 0.010) and endodontic-periodontal (endo-perio) communicating defects (with vs. without, OR = 4.92, P = 0.005) both had a significant influence on the EMS outcome. The negative impact of endo-perio communicating defects was closely associated with tooth type. Premolars with endo-perio communicating defects had significantly higher rates of failure.

CONCLUSION

The EMS outcome is significantly affected by the tooth type and endo-perio communicating defect. The presence of endo-perio communicating defects has a greater negative influence on the success rate for premolars than for anteriors and molars.

Influence of Guided Tissue Regeneration Techniques on the Success Rate of Healing of Surgical Endodontic Treatment: A Systematic Review and Network Meta-Analysis

Several regeneration techniques and materials have been proposed for the healing of bone defects after surgical endodontic treatment; however, the existing literature does not provide evidence on the most recommended techniques or materials. The aim of the present systematic review and network meta-analysis (NMA) is to summarize the clinical evidence on the efficacy of guided tissue regeneration techniques (GRTs). The PRISMA recommendations were followed. Four databases were searched up to December 2021. Randomized clinical trials (RCTs) with a minimum follow-up of 6 months were included. The risk of bias was assessed using the Cochrane Collaboration tool. A fixed effects model and frequentist approach were used in the NMA. Direct GRT technique comparisons were combined to estimate indirect comparisons, and the estimated effect size of the comparisons was analyzed using the odds ratio (OR). Inconsistency was assessed with the Q test, with a significance level of p < 0.01, and a net heat plot. A total of 274 articles was identified, and 11 RCTs (6 direct comparisons of 15 techniques) were included in the NMA, which examined 6 GRT techniques: control, Os, PL, MB, MB + Os, and MB + PL. The MB + Os group compared to the control (OR = 3.67, 95% CI: 1.36–9.90) and to the MB group (OR = 3.47, 95% CI: 1.07–11.3) showed statistically significant ORs (p ˂ 0.05). The MB + Os group presented the highest degree of certainly (P-score = 0.93).

Robotic and Microrobotic Tools for Dental Therapy

Robotic and microrobotic tools such as dental operating microscopes and dental endoscopes are being used extensively in dental therapy, which have a significant impact on dental therapy and education. Herein, this paper reviews the state of the art of robotic and microrobotic tools for dental therapy. This article starts with a brief introduction of current robotic and microrobotic tools for dental therapy and then displays their applications in various dental problems; strengths and weaknesses are also surveyed. Lastly, the conclusion and outlook are discussed, referring to the emerging dental clinic problems and demands. This review is expected to provide guidelines for the therapeutic application of robotic and microrobotic tools and to promote the development of robots in dentistry.

Tooth Loss after Jaw Curettage Surgery: Associated Factors and Potential Benefit of Splint Application

Background

This retrospective study is aimed at (I) assessment of tooth loss and related parameters after jaw curettage of benign lesions and (II) assessment of the outcome of jaw curettage supported by splint insertion after at least six months of follow-up. Material and Methods. For (I), patients who had jaw curettage surgery in the Department of Oral and Maxillofacial Surgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University (Guangzhou, China) from July 2015 to June 2019 were included. For part (II), consecutive patients who came to the department from July to December 2019 that were additionally treated with dental splinting were involved in this study. Based on the patient records, age, gender, initial tooth mobility, follow-up outcome, and potential tooth loss (intra- or postoperatively) were recorded. Based on available radiographs, alveolar crest bone loss and root surface area supported by bone (RSA) were determined.

Results

(I) 128 patients with 305 teeth were included, of which 40 teeth were lost (success rate 86.9%), without statistical difference in gender, age, or tooth type (P > 0.05). Tooth mobility, RSA, and the presence of alveolar crest bone defects were associated to tooth loss (P < 0.001). (II) 17 patients with a medium follow-up period of 11 months (range 9 to 13 months) were enrolled. All lesion-involving teeth supported by splint treatment at risks of loss were preserved, showing an effective tooth retention rate in 17/17 cases (74/74 teeth, success rate: 100%).

Conclusions

Tooth mobility and bone loss (lesion-related and/or periodontal) are potential risk predictors for tooth loss in the first year after jaw curettage surgery. Dental splints could be recommendable for teeth involved by jaw benign lesions with little bone support.

An in vitro investigation of the sealing ability of biodentine and mineral trioxide aggregate as retrofilling materials after the use of various irrigating solutions

Aim:

Materials and Methods:

Statistical Analysis:

Results:

Conclusion:

Comparative evaluation of the apical leakage of different bioceramic retrofilling materials with and without smear layer: A stereomicroscopic study

Objective

Present in-vitro study aimed to evaluate the apical leakage of different bioceramic retrofilling materials with and without smear layer.

Materials and Methods

: Sixty human single-rooted teeth were decoronated at a standardized root length of 13 mm, chemo-mechanically prepared and obturated. After obturation, root-end resection was done and root-end cavities were prepared using ultrasonic tips. The specimens with prepared retro cavities were randomly assigned into 2 groups (n = 30) based on the smear layer removal protocol used. Each group was further subdivided into 3 subgroups (n = 10) based on the bioceramic retrofilling material MTA (Mineral Trioxide Aggregate; Proroot Dentsply/Tulsa), CEM (Calcium-Enriched Mixture; Bionique Dent, Tehran) and ERRM (EndoSequence® Root Repair Material; Brasseler USA, Savannah, GA). The extension of dye (2% Rhodamine B) penetration was measured in millimetre using a stereomicroscope at 10× zoom. Results were statistically analysed using one-way ANOVA (analysis of variance) test and unpaired Student's t test.

Results

In the presence of smear layer, MTA demonstrated maximum mean apical leakage value (1.70 ± 0.30), followed by CEM (1.40 ± 0.37) and ERRM (1.40 ± 0.23), which was statistically not significant. Without the smear layer, ERRM demonstrated the least mean apical leakage value, which was statistically significant as compared with CEM (P <.05) and MTA (P <.01).

Conclusion(s)

: All bioceramic retrofilling materials demonstrated apical leakage irrespective of the presence or absence of the smear layer. The presence of a smear layer is beneficial for the sealing ability of MTA and CEM, whereas, the absence of the smear layer is advocated while using ERRM.

Biocompatibility and Osteogenic Potential of Calcium Silicate-Based Cement Combined with Enamel Matrix Derivative: Effects on Human Bone Marrow-Derived Stem Cells

The characteristics of retrograde filling material are important factors that can affect the long-term success of apical microsurgery. Various calcium silicate-based cements (CSC) were introduced to overcome drawbacks of mineral trioxide aggregate (MTA), while Emdogain is known to be effective in the regeneration of periodontal tissues. The aim of this study is to evaluate the biocompatibility and osteogenic potential of various CSCs combined with Emdogain on human bone marrow-derived mesenchymal stem cells. Experimental groups were classified into eight groups depending on the material and the presence of Emdogain. In the cell-counting kit test, all experimental groups combined with Emdogain showed higher cell viability compared with those without Emdogain at days 1 and 2. In the wound-healing assay, cell migration increased significantly over time, with or without Emdogain. In the alkaline phosphatase assay, all groups treated with Emdogain showed higher activity compared with those without Emdogain at day 3 (p < 0.05). Using alizarin red S staining, all groups treated with Emdogain showed greater calcium nodule formation compared with those without Emdogain at days 7 and 14 (p < 0.05). In conclusion, using CSCs as retrograde filling materials and the application of additional Emdogain will increase bone regeneration and improve the prognosis of apical microsurgery.

Evaluation of YouTube videos for patients' education on periradicular surgery

The aim of this study was to evaluate the content of periradicular surgery-related YouTube videos available for patients' education. YouTube search was made for videos related to periradicular surgery using specific terms. After exclusions, 42 videos were selected, viewed and assessed by two independent observers. The videos were assessed in terms of duration, days since upload, country of upload, number of views, likes and dislikes, authorship source, viewing rate and interaction index. To grade the content of videos about periradicular surgery, a usefulness score was created with 10 elements based mainly on the American Association of Endodontists guidelines. Each element was given a score of 0 or 1. SPSS software (SPSS Inc, Chicago, IL, USA) was used to analyze data at a 95% confidence level. An inter-evaluator reliability analysis for the scoring system was performed using the Kappa statistic. The videos received an average of 35103.9 views (range: 9-652378) with an average duration of 338.71 seconds (range: 42-2081), respectively. Most videos were provided by individuals (57%). Half of the videos were posted by authors from the United States. The inter-evaluator reliability for usefulness scoring was 94.5%. No video covered the 10 scoring elements completely, presenting very low usefulness scores (mean: 3.2; range: 1-7). The most discussed elements were supporting media (100%) and steps of the procedure (90.5%) followed by indications and contraindications (45.2%) and symptoms (31%). None of the included videos discussed the procedure's cost or prognosis. In terms of usefulness score, no significant difference was detected between different sources of upload (chi-square test, P > 0.05). Information on periradicular surgery in YouTube videos is not comprehensive and patients should not rely on YouTube as the only source of information. Dental professionals should enrich the content of YouTube with good quality videos by providing full and evidence-based information that will positively affect patients' attitudes and satisfaction.

Guided tissue regeneration techniques involving blood-derived products in periradicular surgery: a systematic review and meta-analysis protocol

OBJECTIVE

The objective of this review is to evaluate the clinical outcomes of standard periradicular surgery versus periradicular surgery with the use of guided tissue regeneration techniques involving blood-derived products in patients undergoing periradicular surgery.

INTRODUCTION

Guided tissue regeneration techniques have been available in dentistry for decades. Primarily used during periodontal surgery and implant placement, their usefulness in periapical surgery has been garnering increased attention. According to current available evidence, guided tissue regeneration can improve clinical patient outcomes. No systematic reviews have been carried out to investigate guided tissue regeneration techniques involving blood-derived products in periradicular surgery.

INCLUSION CRITERIA

Randomized controlled trials that investigate the outcomes of guided tissue regeneration techniques involving blood-derived products versus standard periradicular surgery technique, will be included for review. Studies will be excluded if they contain patients who have previously undergone periradicular surgery or the treatment was carried out on unrestorable teeth (ie, due to periodontal disease or root fractures).

METHODS

The databases MEDLINE, Embase, Dentistry and Oral Sciences Source, and Cochrane CENTRAL will be used to locate published reports of studies. Reference lists of relevant past systematic reviews will be used to identify further studies. Unpublished studies will be sought using international trials registries and repositories. Two reviewers will carry out independent screening of records for inclusion and the selected studies will be critically appraised prior to data extraction and synthesis. Meta-analysis will be performed if appropriate.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42020222663.

Limitations and Management of Static-guided Endodontics Failure

Endodontic treatment in severely calcified canals is always a challenging task because it can result in accidents such as deviations or perforations. Recently, guided endodontics has become an alternative approach for pulp canal calcification, facilitating the location of root canals more predictably through the combined use of cone-beam computed tomographic imaging, oral scanning, and endodontic access guides. Although several reports have shown that guided endodontics is safer, faster and can be performed without an operating microscope and by less experienced operators, the technique has limitations, and iatrogenesis may occur. This article describes the limitations of static-guided endodontics and possible causes of failures. In the present case, not fixing the guide to the bone and inaccuracies generated by manually performing mesh merger software led to root perforation. Endodontic microsurgery was effective in resolving this case and should be considered the treatment of choice when guided endodontics cannot be used safely or when it fails.

Healing after surgical retreatment at four time points: A retrospective study

AIM

To evaluate the outcome of surgical retreatment at four time points, that is 6, 12, 24 and 48 months post-operatively, and to search for prognostic factors that may affect the outcome.

METHODOLOGY

Clinical records and intraoral periapical radiographs were collected from patients who had undergone surgical retreatment between 2009 and 2015 and attended 6-, 12-, 24- and 48-month follow-up visits. Surgical retreatment was performed by one endodontist and involved minimal root-end resection and maximal length root-end preparation using prebent ultrasonic files. Outcomes were categorized as complete, incomplete, uncertain or unsatisfactory healing, based on clinical and radiographic findings. The complete and incomplete categories were pooled and considered successes, while uncertain and unsatisfactory outcomes were considered failures. Changes in healing outcome were analysed using the McNemar-Bowker test, and prognostic factors were analysed using univariate analysis.

RESULTS

The study cohort included 297 patients with 384 teeth. The overall success rate after 48 months was 90.6% compared with 88.5%, 93% and 92.4% after 6, 12 and 24 months respectively. Age, gender, presence of isthmus and length of canal preparation had no significant influence on the outcome. Lesion size and tooth type had a significant influence only after 6 and 12 months, respectively, with no significant differences at other time points. Fifty per cent of the teeth classified as unsatisfactory or uncertain healing at the 6 months follow-up improved to incomplete or complete healing after 12 months. None of the cases classified as unsatisfactory healing after 12 months subsequently improved, and only 2 cases that were classified as uncertain healing after 12 months improved after 24 months.

CONCLUSIONS

Surgical retreatment was found to be a predictable procedure with a high success rate of 90.6% after 4 years. Over the follow-up periods, only a minor regression in the success rate was found. The 12 months follow-up results closely indicated the long-term outcome of surgical retreatment.

Comparison of Dentinal Tubule Penetration between a Calcium Silicate-Based Sealer with Ultrasonic Activation and an Epoxy Resin-Based Sealer: A Study Using Confocal Laser Scanning Microscopy

OBJECTIVE

 The aim of this study was to compare the degree of dentinal penetration between an epoxy resin-based sealer applied by using two different filling methods and an ultrasonically activated calcium silicate-based sealer via confocal laser scanning microscopy (CLSM).

MATERIALS AND METHODS

 Forty-five extracted permanent maxillary premolars with type II canals (Vertucci's classification) were subjected to the experiment. The root canals were instrumented and distributed randomly into the following three groups: AH Plus + continuous wave technique (AHC group); AH Plus + single cone technique (AHS group); and Endoseal MTA + single cone technique with ultrasonic activation (EMS) group. Each sealer was labeled with rhodamine B dye to allow visualization under CLSM. The sealer penetration depth in each sample was observed at 2 mm and 5 mm from the apex by using CLSM. The data were statistically analyzed by using analysis of variance or Kruskal-Wallis H test according to normality of variable (α = 0.05).

RESULTS

 In all groups, the maximum sealer penetration depth, mean fluorescence intensity, and sum fluorescence intensity values were higher at the 5-mm level than at the 2-mm level. At the 5-mm level, the EMS group showed the lowest value (p = 0.02). At the 2-mm level, there were no statistically significant differences among any of the groups. The AHC group showed higher values than the other groups, but there was no statistically significant difference in the apical area where access of instruments was difficult.

CONCLUSION

 The AHC group showed the highest dentinal tubule penetration, but had questionable filing efficacy in the apical area, which is of particular importance for the success of root canal treatment. Therefore, in areas such as the apical 2 mm of premolars with type II canals, which are difficult to access by using instruments such as heat carriers, other appropriate approaches may be required accordingly.

Possible Causes for Failure of Endodontic Surgery - A Retrospective Series of 20 Resurgery Cases

OBJECTIVE

This study aimed to evaluate unsuccessful endodontic surgery cases for possible causes for treatment failure and evaluate if a nonsurgical retreatment (NSRTX) approach could have been a better alternative to resurgery.

METHODS

Analyses of clinical and cone-beam computed tomography (CBCT) images, periapical radiographs, and chart documentation determined study parameters. Preoperative factors were age, sex, tooth type, signs and/or symptoms, presence of periapical radiolucency, previous root canal treatment, timeline since previous endodontic surgery, presence of posts, cores, and restorations. The intra-operative factors were microsurgical classification, previous techniques, and current techniques utilized. Postoperative factors were signs and/or symptoms, time to follow-up, and healing status. The accessibility of the root canal system and the quality of the existing root filling were used to evaluate NSRTX as an alternative to resurgery.

RESULTS

A total of 1073 surgical cases from 2011-2019 were reviewed. In 14 patients, 20 cases matched the inclusion criteria and allowed for data extraction. The mean time since the previous surgery was 2.9+-2.1 years, with a mean follow-up of 9.1+-5.8 months after the resurgery. Possible reasons for failure identified were: insufficient root-end filling (leaking, off-axis preparation, lack of depth, overfill) n=12/20, 60.0%; missed anatomy (main and lateral canals, isthmus) n=9/20, 45.0%; incomplete resection n=6/20, 30.0%. In 18/20 cases (90.0%), resurgery appeared to be indicated for 2/20 cases (10.0%). Therefore, NSRTX may have been a potential alternative.

CONCLUSION

Further evidence for possible causes of failure of endodontic surgery was provided, which were primarily iatrogenic. The evaluation of CBCT and high magnification intra-operative images proved beneficial for identifying critical issues for all investigated cases.