Modern Endodontic Surgery Concepts and Practice: A Review

Influence of root shape on canal complexity at the mandibular molar apical surgical resection level: A micro-CT study

OBJECTIVES

This study aimed to investigate the relationship between the aspect ratios of mandibular molar roots at the apical 3-mm level and their root canal complexity.

DESIGN

This study used micro-CT imaging to analyze 163 two-rooted mandibular molars. The aspect ratios of the roots at the apical 3-mm level were categorized as "< 2.75" or "≥ 2.75" (mesial) and "< 1.75" or "≥ 1.75" (distal). A two-dimensional (2D) analysis focused on four apical axial cross-section levels to determine the presence of main and accessory canals and isthmus. Additionally, a three-dimensional (3D) assessment of the apical 4-mm of both roots examined main and accessory canals, apical foramina, apical deltas, and middle mesial canals.

RESULTS

Mesial roots with aspect ratios ≥ 2.75 showed a higher number of main canals at all levels compared to those with aspect ratios < 2.75 at the 3-mm level. Additionally, the ≥ 2.75 group exhibited more accessory canals and a higher average number of accessory canals. The 3D assessment confirmed significantly more accessory canals and apical foramina in the ≥ 2.75 group. The prevalence of roots with apical deltas was nearly double in the ≥ 2.75 group, and middle mesial canals were exclusively found in this group. In the distal root, the ≥ 1.75 group showed a significantly higher number of main canals at all axial levels. No significant differences were observed between groups in terms of accessory canals, apical foramina, or deltas.

CONCLUSIONS

A higher root aspect ratio is related to higher anatomical complexity.

Evaluation of a Novel Drilling Approach for Dynamic Navigation-Aided Endodontic Microsurgery: A Surgical Simulation Comparison Study

INTRODUCTION

This study investigated the feasibility of a novel drilling approach that integrates a pilot trephine into dynamic navigation (DN) for guided osteotomy and root-end resection (RER) with unimanual operation in endodontic microsurgery.

METHODS

Two operators with varying levels of DN experience performed guided osteotomy and RER using 2 unimanual drilling methods with DN-aided operation on 3-dimensional printed jaw models. Method 1 (M1) involved drilling with a conventional trephine. Method 2 (M2) involved drilling with a pilot trephine, followed by drilling with a conventional trephine. Accuracy, time, and safety of M1 and M2 were compared. Accuracy measurements included platform deviation (PD), end deviation (ED), angular deviation (AD), resection length deviation (RLD), and resection bevel angle (RBA). Additional parameters included osteotomy and RER time (OT) and bur slippage number (BSN). Statistical analyses were conducted using a 2-sample t-test or Mann-Whitney U test, with the significance level set at .05.

RESULTS

The PD, AD, RBA, and BSN in the M2 group were significantly less than in the M1 group (P < .05). For M1, the novice operator (NO) exhibited significantly higher values of PD, ED, OT, and BSN than the experienced operator (EO) (P < .05). For M2, the NO exhibited significantly higher value of ED only (P < .05), and drilling depth >7 mm was significantly associated with a longer OT (P < .05).

CONCLUSION

In this surgical simulation comparison study, the incorporation of a pilot drill improved the accuracy and safety of DN-aided endodontic microsurgery.

Endodontic Microsurgery Outcomes over 10 Years and Associated Prognostic Factors: A Retrospective Cohort Study

INTRODUCTION

This retrospective cohort study aimed to evaluate long-term healing outcomes (10-17.5 years) after contemporary endodontic microsurgery (EMS) and identify the associated prognostic factors.

METHODS

Clinical and radiographic data of an EMS cohort (2006-2013) from the electronic database of the dental hospital were reviewed retrospectively by 2 independent examiners to determine their survival and healing outcomes, and potential prognostic factors were analyzed by Cox proportional hazards regression and logistic regression (α = 0.05).

RESULTS

Through strict inclusion and exclusion criteria and 721 EMS-treated teeth in the cohort, 309 (42.9%) were included (male = 35.0%; female = 65.0%; age = 45.83 ± 15.53 years) with a mean final follow-up of 152.26 ± 26.37 months (range, 120-211 months; median = 148 months). Clinical and radiographic assessments found an 80.5% 10-year survival rate with 63.4% of success. Collectively, tooth type, tooth mobility, preoperative lesion size, clinical crown-to-root ratio, and crown restorations at follow-up were significantly associated with long-term success and survival over 10 years.

CONCLUSIONS

The preoperative status and condition of the tooth including its alveolar bone support and adequate full-crown restorations may be relevant prognostic determinants of success and survival after EMS over time.

Efficacy of the GentleWave System in the removal of biofilm from the mesial roots of mandibular molars before and after minimal instrumentation: An ex vivo study

AIM

To compare the efficacy of Enterococcus faecalis biofilm removal using the GentleWave System (GWS) (Sonendo Inc, CA) on non-instrumented versus minimally instrumented root canal systems.

METHODOLOGY

Thirty-four mandibular molars were autoclaved and allocated to four groups: Negative control (n = 5); positive control (n = 5); Group 1: non-instrumentation + GWS (NI + GWS) (n = 12); and Group 2: minimal instrumentation + GWS (MI + GWS) (n = 12). Of 34 samples, 24 samples with Vertucci type 2 configuration within the mesial root of each sample were allocated to Groups 1 and 2 and then matched based on the working length and root canal configuration. After inoculation of samples with E. faecalis for 3 weeks, the GWS was used on Group 1 without any instrumentation and Group 2 after instrumentation of mesial canals until size 20/06v. CFU and SEM analysis were used.

RESULTS

Log10 (CFU/mL) from the positive control, and Group 1 and 2 were 7.41 ± 0.53, 3.41 ± 1.54, and 3.21 ± 1.54, respectively. Both groups showed a statistically significant difference in the reduction of viable E. faecalis cells compared to the positive control (Group 1 [p = .0001] and Group 2 [p < .0001]), whilst showing no significant difference between the two tested groups (p < .05).

CONCLUSION

The use of GWS on the non-instrumented root canal system could be an effective disinfection protocol in removing the biofilm without dentin debris formation.

Advancements in guided surgical endodontics: A scoping review of case report and case series and research implications

This scoping review examined current case series and reports on guided surgical endodontic applications in order to provide a critical platform for future research. Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for scoping reviews guidelines were followed. A search on PubMed and Scopus yielded 611 articles, with 17 case reports and 1 series meeting inclusion criteria. Overall, guided surgery addressed anatomical complexities, with 15 articles employing static protocols and 3 dynamic. Results showed minimal iatrogenic errors and reduced chair time, with no postoperative issues reported. Within the cases described, guided endodontic surgery exhibited satisfactory results in management of anatomical complex cases. Cost-effectiveness, the need for adequate follow-up, procedure's reproducibility and accuracy, and objective measurement of the reduction in operative times and iatrogenic errors are some of the limitations in the current reports that need to be considered for planning of future experimental and cohort studies.

Efficacy of root-end filling techniques using premixed putty type bioceramic cements: an ex vivo study

OBJECTIVES

Currently, premixed putty-type bioceramic cements (PPBCs) have become popular materials for root-end fillings. This study investigated three root-end filling techniques using PPBCs and calcium silicate-based sealers including EDTA pretreatment.

MATERIALS AND METHODS

Ninety root segments were prepared and standardized with an artificial fin and lateral canal, and assigned to three groups (n = 30). Root-end fillings were placed using BC-RRM Putty alone (Group PA), injection of BC sealer followed by BC-RRM Putty (Lid Technique: Group LT) or BC-RRM Putty with BC sealer coating (Deep putty packing technique: Group DP). Half of each group was pretreated with 17% EDTA. The radiographic images of the specimens were assessed by five graders and push-out bond strength tests were conducted. The data were analyzed with a general linear model including two-way ANOVA and chi-square test at a significance level of 5%.

RESULTS

DP approach demonstrated significantly higher bond strength than LT (P < 0.05). However, there was no statistically significant difference in bond strength between PA and either DP or LT. EDTA pretreatment had no significant effect on push-out bond strength. Radiographically, for the main canal, PA and DP scored significantly higher than LT. In the fin, PA scored significantly higher than others (P < 0.05).

CONCLUSION

Our study highlights variations in root-end filling techniques. Injecting a bulk of bioceramic sealer before the placement of PPBCs may reduce bond strength and radiopacity. The application of PPBCs alone or in the deep putty technique demonstrates potential for favorable outcomes. EDTA pretreatment did not enhance bond-strength.

CLINICAL RELEVANCE

Careful selection and application of bioceramic materials and techniques in root-end fillings may influence the outcome of endodontic root-end surgery. When PPBCs and calcium silicate-based sealers are used together for root-end fillings, sealer followed by deep putty application may offer improved bond strength and radiographic fill compared to the lid technique.

Bacterial sealing ability of calcium silicate-based sealer for endodontic surgery: an in-vitro study

BACKGROUND

Apical surgery with standard retrograde maneuvers may be challenging in certain cases. Simplifying apical surgery to reduce operating time and streamline retrograde manipulation is an emerging need in clinical endodontics.

AIM OF THE STUDY

The aim of the study was to compare the bacterial sealing ability of a calcium silicate-based sealer with the single cone technique combined with root end resection only, and calcium silicate-based sealer as a retrograde filling versus MTA retrofilling, and to analyze bacterial viability using confocal laser scanning microscope (CLSM).

MATERIALS AND METHODS

In this in vitro experimental study, 50 extracted human maxillary incisor teeth were instrumented and randomly divided into five groups: three experimental groups, a positive control group, and a negative control group (n = 10/group). In the experimental groups, the roots were obturated using the single cone technique (SCT) and a calcium silicate-based sealer. In group 1, the roots were resected 3 mm from the apex with no further retrograde preparation or filling. In groups 2 and 3, the roots were resected, retroprepared, and retrofilled with either a calcium silicate-based sealer or MTA, respectively. Group 4 (positive control) was filled with a single gutta-percha cone without any sealer. In group 5 (negative control), the canals were left empty, and the roots were sealed with wax and nail varnish. A bacterial leakage model using Enterococcus faecalis was employed to assess the sealing ability over a 30-day period, checking for turbidity and analyzing colony forming units (CFUs) per milliliter. Five specimens from each group were examined using CLSM for bacterial viability. Data for the bacterial sealing ability were statistically analyzed using chi-squared and Kruskal-Wallis tests.

RESULTS

The three experimental groups did not show significant differences in terms of bacterial leakage, or bacterial counts (CFUs) (P > 0.05). However, significant differences were observed when comparing the experimental groups to the positive control group. Notably, the calcium silicate-based sealer, when used as a retrofilling, yielded the best sealing ability. CLSM imaging revealed viable bacterial penetration in all the positive control group specimens while for the experimental groups, dead bacteria was the prominent feature seen.

CONCLUSION

Within the limitations of this study, it could be concluded that the bacterial sealing ability of calcium silicate-based sealer with the single cone technique combined with root end resection only and calcium silicate-based sealer as a retrograde filling were comparable with MTA retrofilling during endodontic surgical procedures.

Accuracy and efficiency of dynamic navigated root-end resection in endodontic surgery: a pilot in vitro study

BACKGROUND

The operation accuracy and efficiency of dynamic navigated endodontic surgery were evaluated through in vitro experiments. This study provides a reference for future clinical application of dynamic navigation systems in endodontic surgery.

MATERIALS AND METHODS

3D-printed maxillary anterior teeth were used in the preparation of models for endodontic surgery. Endodontic surgery was performed with and without dynamic navigation by an operator who was proficient in dynamic navigation technology but had no experience in endodontic surgery. Optical scanning data were applied to evaluate the length and angle deviations of root-end resection. And the operation time was recorded. T tests were used to analyze the effect of dynamic navigation technology on the accuracy and duration of endodontic surgery.

RESULTS

With dynamic navigation, the root-end resection length deviation was 0.46 ± 0.06 mm, the angle deviation was 2.45 ± 0.96°, and the operation time was 187 ± 22.97 s. Without dynamic navigation, the root-end resection length deviation was 1.20 ± 0.92 mm, the angle deviation was 16.20 ± 9.59°, and the operation time was 247 ± 61.47 s. Less deviation was achieved and less operation time was spent with than without dynamic navigation (P < 0.01).

CONCLUSION

The application of a dynamic navigation system in endodontic surgery can improve the accuracy and efficiency significantly for operators without surgical experience and reduce the operation time.

Novel self-setting cements based on tricalcium silicate/(β-tricalcium phosphate/monocalcium phosphate anhydrous)/hydroxypropyl methylcellulose: From hydration mechanism to biological evaluations

Despite the clinical success of tricalcium silicate (TCS)-based materials in endodontics, the inferior handling characteristic, poor anti-washout property and slow setting kinetics hindered their wider applications. To solve these problems, an injectable fast-setting TCS/β-tricalcium phosphate/monocalcium phosphate anhydrous (β-TCP/MCPA) cement was developed for the first time by incorporation of hydroxypropyl methylcellulose (HPMC) and β-TCP/MCPA. The physical-chemical characterization (setting time, anti-washout property, injectability, compressive strength, apatite mineralization and sealing property) of TCS/(β-TCP/MCPA) were conducted. Its hydration mechanism was also investigated. Furthermore, the cytocompatibility and osteogenic/odontogenic differentiation of stem cells isolated from human exfoliated deciduous teeth (SHED) treated with TCS/β-TCP/MCPA were studied. The results showed that HPMC could provide TCS with good anti-washout ability and injectability but slow hydration process. However, β-TCP/MCPA effectively enhanced anti-washout characteristics and reduced setting time due to faster hydration kinetics. TCS/(β-TCP/MCPA) obtained around 90 % of injection rate and high compressive strength whereas excessive additions of β-TCP/MCPA compromised its injectability and compressive strength. TCS/(β-TCP/MCPA) can induce apatite deposition and form a tight marginal sealing at the dentin-cement interface. Additionally, TCS/(β-TCP/MCPA) showed good biocompatibility and promoted osteo/odontogenic differentiation of SHED. In general, our results indicated that TCS/(β-TCP/MCPA) may be particularly promising as an injectable bioactive cements for endodontic treatment.

Surgical Management of Radicular Cyst With the Use of Advanced Platelet-Rich Fibrin and Bone Graft: A Case Report

In addition to helping with wound healing, periapical surgery is performed to remove periapical disease. Concentrates of platelets have been applied extensively in endodontics and other fields of regenerative medicine. A periapical inflammatory lesion was found in a 35-year-old male patient who complained of pain in the maxillary anterior region and displayed slight edema in the same area. The lesion was treated with periapical surgery utilizing advanced platelet-rich fibrin (A-PRF). Mesenchymal stem cell processes of proliferation and differentiation can be induced by several types of platelet concentrates. Growth factors are released at the application site by platelet-rich fibrin (PRF) for a minimum of seven days. The activity of osteoblasts is stimulated by growth factors and secreted cytokines. Furthermore, the release of growth factors promotes fibroblast migration, which quickens tissue regeneration.  In addition to helping with wound healing, periapical surgery is performed to remove periapical disease. The synthesis of fibrin networks laden with platelets and growth factors is made possible by PRF, which is subsequently used to accelerate bone regeneration and, consequently, to improve bone formation. In this instance, the best possible bone regeneration and repair were accomplished. After 12 weeks, 24 weeks, and 36 weeks, the patient was brought back for follow-ups. He was found to be asymptomatic, and the radiograph showed considerable periapical healing with nearly enough bone production.

Robot-Assisted and Haptic-Guided Endodontic Surgery: A Case Report

There has been a significant increase in robot-assisted dental procedures in the past decade, particularly in the area of robot-assisted implant placement. The objective of this case report was to assess the initial use of the Yomi Robot's assistance and haptic guidance during endodontic microsurgery. The robot was used during the osteotomy and root-end resection of the first and second upper left premolars. The report aims to inform clinicians of the initial implementation of this cutting-edge technology in endodontics and its potential to enhance endodontic microsurgery. The Yomi Robot was used in performing osteotomy and root-end resection during apical surgery in a patient presenting with symptomatic upper left first and second premolars. The treatment procedure was decided after clinical examination, chart data, and radiographic examinations, which showed periapical lesions on both premolars, taking into consideration the failed endodontic retreatment on the first premolar, the post and ceramic coronal restorations on both teeth, and the desire of the patient to save them. The Yomi Robot system provides auditory, visual, and physical guidance to clinicians during surgery while using a cone-beam computed tomography scan for precision planning with greater accuracy and minimized potential for human error. Further studies are needed to prepare a protocol for robotic-guided procedures in endodontics.

3D finite element analysis of stress distribution on the shape of resected root-end or with/without bone graft of a maxillary premolar during endodontic microsurgery

Background/purpose

Apical root resection pattern affects the stress distribution behavior in the apical region of the resected tooth. The purpose of the study was to compare the biomechanical responses of resected teeth between endodontic microsurgery (horizontal resection) and targeted endodontic microsurgery (round resection).

Materials and methods

Five different models were developed. The basic model without resection (NR) was regarded as the control model, and the others involved: horizontal resection without bone grafting (HN), horizontal resection with bone grafting (HG), round resection without bone grafting (RN), and round resection with bone grafting (RG) models. A static load of 100 N was applied to the buccal and palatal cusps of all the teeth in a 30° oblique direction. The maximum von-Mises stress and tooth displacement values were analyzed and compared.

Results

Both the HN and RN models exhibited lower stress distribution values on bone compared with the NR (control) model. Regarding maximum stress distribution at the root apex, the stress value of the RN model was slightly higher compared to the HN model, whereas the RG model displayed a slightly lower stress value in comparison with the HG model. For maximum tooth displacement value, there were no significant differences between the HN and RN models, as well as the HG and RG models.

Conclusion

The round resection pattern had comparable stress distribution behaviors at the root apex and tooth displacement values with the horizontal resection pattern. Targeted endodontic microsurgery might provide better biomechanical response of the resected tooth after root-end resection.

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

Background

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.

Aims

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.

Materials and Methods

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.

Results

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).

Conclusions

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.

Comparison of the sealing ability amongst orthograde apical plugs of mineral trioxide aggregate plus, mineral trioxide aggregate repair HP, and Biodentine after root resection: a bacterial leakage study

This study aimed to analyse the effect of root-end resection on the sealing ability of orthograde apical plugs of three root-end filling materials (MTA Repair HP, Biodentine, MTA Plus) using the bacterial leakage method and compare it with the retrograde root-end filling technique. Eighty-four extracted mandibular premolar teeth with single root and single straight canals were selected and randomly divided into two main experimental groups (n = 36) depending on the apical plug placement technique and a control: Group I: orthograde technique, followed by root-end resection; Group II: retrograde root-end filling technique; one control Group III (n = 12): obturation with gutta-percha, followed by root-end resection. Experimental groups were further subdivided into three subgroups A, B, and C (n = 12) depending on the three different root-end filling materials used. An apical plug of 3 mm thickness was obtained in both the experimental groups. The apical sealing ability was evaluated with the dual-chamber bacterial leakage method. Statistical analysis was performed using the Kaplan-Meier survival analysis test. By the end of 30 days, the occurrence of turbidity indicating bacterial leakage was 75% in MTA Repair HP, 83.3% in Biodentine, and 91.7% in MTA Plus samples. This trend of turbidity was similar in both orthograde and retrograde technique. The control group showed turbidity in all the samples (100%). More MTA Repair HP samples (25%) survived the 30 days observation period with no bacterial leakage compared to Biodentine (16.7%) and MTA Plus (8.3%). The sealing ability of already set root-end filling materials placed through the orthograde technique did not deteriorate after root-end resection. Also among three root-end filling materials, MTA Repair HP presented the lowest bacterial microleakage followed by Biodentine and MTA Plus, respectively.

Dynamically guided transantral piezoelectric endodontic microsurgery: A case report with technical considerations

AIM

Endodontic microsurgery (EMS) of maxillary molars may represent a complex challenge to the clinician due to the location of the roots and the proximity of the maxillary sinus floor. This report aimed to describe the simultaneous use of a computer-assisted dynamic navigation (C-ADN) system and piezoelectric bony-window osteotomy for the transantral microsurgical approach of a maxillary left first molar with adequate root canal filling and symptomatic apical periodontitis.

SUMMARY

This case report highlights the importance of C-ADN to carry out a minimally invasive buccal surgical access to palatal roots affected by apical periodontitis and provides a practical example to help clinicians make treatment decisions based on the available evidence. Clinical and tomographic evaluations were performed before the surgical procedure and at 24-month follow-up. This case was treated using a C-ADN system fitted to a piezotome for the buccal approach of the buccal roots, maxillary sinus membrane lifting, and for transantral location, root-end resection, cavity preparation, and filling of the palatal root. The navigation system allowed to achieve an accurate apical canal terminus location and root-end filling of the three roots with a minimally invasive piezoelectric crypt approach. At the 24-month follow-up examination, the patient remains asymptomatic, with normal periapical structures, and regeneration of maxillary sinus walls. It was concluded that the combination of dynamic navigation with piezoelectric bony-window osteotomy offers enhanced accuracy, tissue preservation, diminished risk of iatrogenic complications, and could maximize success and survival rates in transantral EMS.

Assessment of different irrigation techniques on the penetration depth of different sealers into dentinal tubules by confocal laser scanning microscope: An in vitro comparative study

Background

The effective disinfection of the entire root canal system aids in the penetration of irrigants into the dentinal tubules further improving sealer penetration and achieving a three-dimensional seal in endodontically treated teeth. Various final irrigation techniques can be employed to achieve this goal. Therefore, this study intended to assess and compare the efficacy of three final irrigation techniques on the depth of penetration of two root canal sealers into dentinal tubules using confocal laser scanning microscope (CLSM).

Methods

Forty-eight single-rooted mandibular premolars were selected and decoronated to a length of 12 mm. All the samples were prepared using ProTaper Gold rotary files and divided into three groups: Group 1 - Conventional syringe irrigation (CSI), Group 2 - passive ultrasonic irrigation (PUI), and Group 3 - Pro-agitator tip system (PATS). Each group was divided into two subgroups: Subgroup A - AH Plus and Subgroup B - GuttaFlow Bioseal (GFB). Then, sealers were mixed with 0.1% rhodamine B dye and the samples were obturated. All the samples were sectioned at 2 mm and 5 mm from the apex and visualized under confocal laser scanning microscope (CLSM) (10×) for maximum mean penetration depth and percentage of sealer penetration. Statistical analysis was done using the independent t-test and one-way analysis of variance test, followed by Tukey's Post hoc analysis.

Results

PUI performed better in the apical third, whereas PUI and PATS showed comparable results in the middle third for both depth and percentage of sealer penetration. Among the two sealers, GFB performed better than AH Plus in both the apical and middle third. These values were statistically significant. (P < 0.05).

Conclusion

Final irrigation activation with PUI or PATS can significantly improve sealer penetration. The average depth of penetration of GFB both at the middle and apical third of the root was significantly superior to AH Plus.

The outcome of combined use of iRoot BP Plus and iRoot SP for root-end filling in endodontic microsurgery: a randomized controlled trial

OBJECTIVES

Root-end filling is important for the clinical outcome of endodontic microsurgery. Our previous study showed that combined application of iRoot BP Plus Root Repair Material (BP-RRM) and iRoot SP Injectable Root Canal Sealer (SP-RCS) in root-end filling exhibited better apical sealing as compared to the application of BP-RRM alone. The aim of this randomized controlled clinical trial was to evaluate the effect of the combined use of BP-RRM and SP-RCS on the prognosis of teeth with refractory periapical diseases after endodontic microsurgery.

MATERIALS AND METHODS

240 teeth with refractory periapical diseases scheduled for endodontic microsurgery were randomly divided into BP-RRM/SP-RCS group (n = 120) and BP-RRM group (n = 120). The patients were followed up at 3 months, 6 months, and 12 months after endodontic microsurgery. Pre- and post-operative clinical and radiographic examinations were performed to evaluate the treatment outcome. The 1-year success rate of endodontic microsurgery in BP-RRM/SP-RCS and BP-RRM groups was compared by Chi-square test. Factors that might impact the prognosis were further analyzed using Chi-square test or Fisher's exact test.

RESULTS

A total of 221 teeth completed the 12-month follow-up. The 1-year success rates of the BP-RRM/SP-RCS and BP-RRM groups were 94.5% (104/110) and 92.8% (103/111), respectively. The combined use of BP-RRM and SP-RCS achieved a clinical outcome comparable to BP-RRM alone (P = 0.784). Tooth type (P = 0.002), through-and-through/apico-marginal lesion (P = 0.049), periodontal status (P < 0.0001), and Kim's lesion classification (P < 0.0001) were critical factors associated with the 1-year success of endodontic microsurgery.

CONCLUSIONS

The combined use of BP-RRM and SP-RCS is a practicable method for root-end filling in endodontic microsurgery with a satisfactory 1-year clinical outcome.

CLINICAL RELEVANCE

The combined application of BP-RRM and SP-RCS in EMS is an effective root-end filling method with a satisfactory 1-year clinical outcome.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry (ChiCTR2100052174).

The use of guided tissue regeneration in endodontic Microsurgery: Setting a threshold

Aim

We aimed to compare the radiographic outcomes of conventional and regenerative approaches in endodontic microsurgery (EMS) and set a critical defect size for healing in conventional and regenerative therapies.

Methodology

The study evaluated 53 root canal-treated teeth (33 patients) with periapical lesions. Among them, 19 teeth (35.8 %) were treated with regenerative treatment, whereas 34 teeth (64.1 %) were managed with the conventional approach. Conventional and regenerative approaches were performed by endodontic and periodontic residents under consultants' supervision. Healing was evaluated after a minimum period of 6 months by comparing pre- and post-operative cone-beam computed tomography (CBCT) findings. The radiographic interpretation was conducted by a single examiner who was not participating in the surgeries and was blind on the type of treatment prior to CBCT evaluation. New healing criteria were proposed owing to the limitations on the present criteria in evaluating endodontic surgery after regenerative treatment. Critical measurements were calculated for each approach based on periapical lesion dimensions.

Results

The regenerative approach presented significantly better healing than conventional treatment (mean, 1.21 and 1.59, respectively; p = 0.047). Based on the critical-point calculations, the conventional approach was effective in lesions of up to 3 mm depth and height, whereas the regenerative approach resulted in better healing rates in lesions with 3-9 mm depth and 3-6 mm height.

Conclusions

Performing the regenerative approach in EMS resulted in better healing rates than those of the conventional approach. The conventional approach is recommended for small periapical lesions, whereas the first had better results in larger lesions.

Biocompatibility of mineral trioxide aggregate and biodentine as root-end filling materials: an in vivo study

This study evaluated the biocompatibility of mineral trioxide aggregate (MTA) and Biodentine (BD) as root-end filling materials. Six mongrel dogs were divided into two equal groups according to the evaluation period; group A: one month and group B: three months. Three premolars of the same quadrant in each arch were used, summing up 36 teeth (6 teeth/dog). These teeth were randomly subdivided into three subgroups according to the root-end filling material used: MTA, BD and no root-end filling material (control). Endodontic access cavities were performed for induction of periapical pathosis. After the infection period, root canal instrumentation and obturation were accomplished. One day after root canal procedures, root-end surgery was performed. Surgical access was achieved and the root-end was resected approximately 3 mm above the apex. Root-end cavity was prepared ultrasonically and filled with the tested materials. All samples were evaluated by radiography and histopathology (Inflammation and new hard tissue formation). Data were collected and subjected to statistical analysis. In group A, MTA subgroup exhibited significant higher mean inflammatory score than BD subgroup (P < 0.05) while no significant difference was recorded between MTA and BD subgroups in group B (P > 0.05). Regarding mean mineralization score, there was no significant difference between all subgroups in both groups A and B (P > 0.05). Biodentine exhibited favorable biocompatibility in the initial stage of healing than MTA and comparable biomineralization. Clinical relevance: Biodentine could be considered as an acceptable alternative to MTA in peri-radicular surgeries.

Outcome of curcumin-based photodynamic therapy in endodontic microsurgery: A case report

INTRODUCTION

Persistent apical periodontitis after root canal treatment may require surgical retreatment when non-surgical options are ineffective or impractical due to anatomical challenges or iatrogenic errors. Endodontic microsurgery (EMS) is a precise technique that aims to overcome extraradicular biofilm and root morphology issues. Photodynamic therapy (PDT) is an emerging supplementary disinfection approach that utilizes a photosensitizer agent and light to eliminate microorganisms through oxidative reactions.

REPORT

A 60-year-old male with persistent apical periodontitis in a left maxillary first molar underwent non-surgical root canal retreatment followed by surgical reintervention due to anatomical complexities. During surgery, PDT was performed using a novel curcumin-based photosensitizer agent. After the procedure, the tooth was retrofilled with bioceramic cement, and photobiomodulation was applied to enhance tissue healing. One year post-surgery, the patient exhibited complete periradicular repair and remained asymptomatic.

DISCUSSION

EMS is considered a last resort to salvage an endodontically treated tooth and has shown moderate success rates. PDT has demonstrated promise in improving periapical healing and reducing microorganisms. In this case, curcumin, diluted with 2 % chlorhexidine gel, served as an effective photosensitizer agent with antimicrobial properties. Moreover, performing photobiomodulation aided in cell recovery and reduced postoperative discomfort.

CONCLUSION

The proposed EMS treatment protocol with PDT using curcumin yielded positive outcomes in this case report. Further randomized clinical trials are necessary to assess the efficacy of this approach in EMS. Additionally, further research on curcumin-based photosensitizer agents encapsulated in nanoparticles and enhanced antimicrobial agents is recommended to refine this treatment protocol for routine use.

A novel simplified approach for endodontic retrograde surgery in short single-rooted teeth

BACKGROUND

High technical thresholds, long operative times, and the need for expensive and specialized equipment impede the widespread adoption of endodontic microsurgery in many developing countries. This study aimed to compare the effects of a simplified, cost-effective, and time-efficient surgical approach involving orthograde obturation using biological ceramic material greater than 6 mm combined with apicoectomy for single-rooted teeth with short lengths with those of the conventional and current standard methods.

MATERIALS AND METHODS

Forty-five premolars equally categorized into three groups: conventional surgery group, standard surgery group, and modified surgery group. A µCT scan was used to calculate the volume of voids. A micro-leakage test and scanning electron microscope (SEM) were performed to assess the sealing effect. Additionally, four cases of chronic periapical periodontitis in the anterior region were selected, and the patients received either the modified approach or the standard surgery for endodontic microsurgery.

RESULTS

The volumes of voids in the apical 0-3 mm of the modified group and the standard group were comparable. The micro-leakage test and SEM examination demonstrated closely bonded fillings in the dentinal walls in both the modified surgery group and standard surgery group. The outcomes of the preliminary application of this modified procedure on patients were successful at the time of the follow-up cutoff.

CONCLUSIONS

The modified surgery group exhibited similar root canal filling and apical sealing abilities with the standard procedure for single-rooted teeth with short lengths (< 20 mm). The preliminary application of this modified surgical procedure achieved favorable results.

Finite element evaluation of dentin stress changes following different endodontic surgical approaches

The aim was to compare the effect of different endodontic surgical treatments on the stress distributions in dentin of a simulated first mandibular molar tooth using the finite element analysis method. Three surgical endodontic procedures (apical resection, root amputation, and hemisection) were simulated in a first mandibular molar. Biodentine or mineral-trioxide-aggregate was used to repair the surgery site in apical resection and root amputation models; the remaining root canal spaces were filled with gutta-percha. Access cavities were restored using resin composite. In hemisection model, root canal was filled with gutta-percha, and coronal restoration was finished with a monolithic zirconia crown. A sound tooth model was created as a control model. An oblique force of 300 N angled at 45° to the occlusal plane was simulated. Maximum von Mises stresses were evaluated in dentin near the surgery regions and the entire tooth. Apical resection/Biodentine and apical resection/mineral-trioxide-aggregate models generated maximum von Mises stresses of 39.001 MPa and 39.106 MPa, respectively. The recorded maximum von Mises stresses in root amputation models were 66.491 MPa for root amputation/Biodentine and 73.063 MPa for root amputation/mineral-trioxide-aggregate models. The highest maximum von Mises stress value among all models was observed in the hemisection model, measuring 138.87 MPa. Hemisection induced the highest von Mises stresses in dentin, followed by root amputation and apical resection. In apical resection, Biodentine and mineral-trioxide-aggregate did not show a significant difference in stress distribution. Biodentine in root amputation may lead to lower stresses compared to mineral-trioxide-aggregate.

Computer guided root tip extraction and implant placement: A clinical report

Extraction of a residual root tip and implant placement can be challenging because of the complexity and invasiveness of the procedure. Improvised application of a guided implant surgery may avoid such challenges. This clinical report presents an innovative technique combining a 3-dimensionally printed surgical guide with conventional instrumentation for a residual root tip extraction in a minimally invasive and predictable way.

Interfacial adaptation of NeoMTA Plus, BioRoot RCS and MTA in root-end cavities: A micro-CT study

AIM

This study aimed to use the micro-computed tomography to evaluate the interfacial adaptation and the presence of gaps of NeoMTA Plus, BioRoot RCS, and MTA in the root-end cavities.

METHODOLOGY

Thirty standardized bovine roots measuring 15 mm in length were selected. Chemical-mechanical preparation was performed up to instrument #80 and obturation with the cold lateral compaction technique with cement based on zinc oxide and eugenol. The roots were kept at 37°C for 7 days. Afterward, apicectomy of the apical 3 mm and a root-end filling cavity was performed at 3 mm depth. Micro-computed tomography (micro-CT) was performed to measure the volume of the retroactivity. The roots were divided by stratified randomization into three groups according to the retro-end filling material: NeoMTA Plus, BioRoot RCS, and MTA. A new micro-CT was performed to assess the presence of voids in the root-end filling material and between it and the canal wall. One-way ANOVA and Tukey tests were performed using the BioEstat 4.0 program.

RESULTS

There was no difference in the initial volume values of the root-end cavities (p > .05). After the insertion of root-end filling materials, the most significant volumes of voids were observed in the NeoMTA Plus group (p < .05), with no difference for the BioRoot RCS and MTA Angelus groups (p > .05).

CONCLUSION

Micro-computed tomography showed that MTA and BioRoot RCS have better interfacial adaptation and presented fewer number of gaps than NeoMTA Plus when used as root-end filling materials.

RESEARCH HIGHLIGHTS

Micro-computed tomography evaluation of different root-end fillings materials.

Analysis of mandibular molar anatomy in Taiwanese individuals using cone beam computed tomography

Background/purpose

Before periapical surgery in the mandibular posterior teeth is performed, the thicknesses of the buccal alveolar bone wall and buccolingual root might be a critical issue. This study aimed to assess the anatomical structure of the posterior region of the mandible in Taiwanese individuals using cone-beam computed tomography (CBCT).

Materials and methods

The CBCT images of 96 Taiwanese individuals (51 male and 45 female), which included 192 mandibular first molars and 192 mandibular second molars, were imported into medical imaging software to measure the buccal alveolar bone thickness and buccolingual root thickness at 3 mm above the root apex. Statistical analysis was conducted to examine the impact of tooth position, gender, and age on the anatomical position of mandibular molars.

Results

The buccal alveolar bone thickness at 3 mm above the root apex of the mandibular second molar demonstrates a significantly higher value when compared to that of the first molar. Nonetheless, concerning the buccolingual root thickness, no significant differences were observed between these two teeth. In addition, the buccal alveolar bone thickness and buccolingual root thickness at 3 mm above the root apex may not be influenced by gender and age.

Conclusion

The anatomical structures of the posterior region of the mandible in Taiwanese individuals exhibited variations between the mandibular first and second molars. However, these differences were not influenced by gender or age.

Effect of Endo-Z bur or Bladesonic ultrasonic tip on the adaptation of filling material. A micro-CT study

This study aimed to evaluate the effect of apicoectomy performed with a bur or an ultrasonic tip on the adaptation of the filling material to root canal dentin. Twenty human mandibular incisors were selected and prepared with a ProDesign Logic system up to diameter 40/.05. The root canals were filled with Bio-C Sealer (Angelus, PR, Brazil) using the single cone technique and were stored at 37ºC and 95% relative humidity for 7 days. After this period, the apicoectomy of the 3 millimeters of the root apex was performed using Endo-Z bur (Dentsply Sirona) or Bladesonic ultrasonic tip (Helse Ultrasonic, Santa Rosa de Viterbo, Brazil) (n=10). The specimens were scanned by micro-computed tomography (micro-CT; SkyScan 1176) with a voxel size of 8.74 µm after obturation and after apicoectomy. The percentage of voids at the interface between the filling material and the root canal wall was evaluated in the apical 4 mm of the root after apicoectomy, besides the time cutting to both devices. The data obtained were submitted to paired and unpaired t-tests (α = 0.05). Endo-Z and Bladesonic increased the percentage of voids between the filling material and the dentin after apicectomy (p<0.05), and they were similar (p>0.05). Endo-Z has a shorter time to perform apicoectomy compared to Bladesonic (p<0.05). Apicectomies with Endo-Z or Bladesonic could harm the material/dentin interface, while the Endo-Z bur was faster than the Bladesonic ultrasonic tip.

Materials and Applications of 3D Printing Technology in Dentistry: An Overview

PURPOSE

This narrative review aims to provide an overview of the mechanisms of 3D printing, the dental materials relevant to each mechanism, and the possible applications of these materials within different areas of dentistry.

METHODS

Subtopics within 3D printing technology in dentistry were identified and divided among five reviewers. Electronic searches of the Medline (PubMed) database were performed with the following search keywords: 3D printing, digital light processing, stereolithography, digital dentistry, dental materials, and a combination of the keywords. For this review, only studies or review papers investigating 3D printing technology for dental or medical applications were included. Due to the nature of this review, no formal evidence-based quality assessment was performed, and the search was limited to the English language without further restrictions.

RESULTS

A total of 64 articles were included. The significant applications, applied materials, limitations, and future directions of 3D printing technology were reviewed. Subtopics include the chronological evolution of 3D printing technology, the mechanisms of 3D printing technologies along with different printable materials with unique biomechanical properties, and the wide range of applications for 3D printing in dentistry.

CONCLUSIONS

This review article gives an overview of the history and evolution of 3D printing technology, as well as its associated advantages and disadvantages. Current 3D printing technologies include stereolithography, digital light processing, fused deposition modeling, selective laser sintering/melting, photopolymer jetting, powder binder, and 3D laser bioprinting. The main categories of 3D printing materials are polymers, metals, and ceramics. Despite limitations in printing accuracy and quality, 3D printing technology is now able to offer us a wide variety of potential applications in different fields of dentistry, including prosthodontics, implantology, oral and maxillofacial, orthodontics, endodontics, and periodontics. Understanding the existing spectrum of 3D printing applications in dentistry will serve to further expand its use in the dental field. Three-dimensional printing technology has brought about a paradigm shift in the delivery of clinical care in medicine and dentistry. The clinical use of 3D printing has created versatile applications which streamline our digital workflow. Technological advancements have also paved the way for the integration of new dental materials into dentistry.

Enucleation of jaw cyst combined with intentional replantation to retain cyst-involved teeth

BACKGROUND

Jaw cysts often deeply involve adjacent tooth roots, making it difficult to preserve them. The purpose of this retrospective study was to investigate the effectiveness of an intentional replantation (IR) strategy combined with cyst enucleation in preserving cyst-involved teeth during jaw cyst removal.

MATERIALS AND METHODS

Fifteen patients with jaw cysts and deeply involved teeth were treated with IR and cyst enucleation. All patients received root canal therapy prior to surgery, except for one patient who received it during surgery. The involved teeth were extracted, and the root surface was carefully cleaned before IR and cyst enucleation. Patients were followed up for 12-14 months, with indicators including clinical complaints, replanted tooth stability, and root resorption.

RESULTS

No cyst recurrence was observed, and all replanted teeth survived with good local gingival condition and no marked swelling or recession. Radiographic findings showed clear periodontal space surrounding the replanted teeth. One replanted tooth exhibited slight root resorption due to occlusal trauma, but the resorption ceased after occlusal adjustment.

CONCLUSIONS

IR combined with cyst enucleation is an effective strategy for thoroughly cleaning jaw cysts and preserving teeth involved in the cyst.

Periapical healing following endodontic microsurgery with collagen-based bone-filling material: A randomized controlled clinical trial

AIM

To evaluate two- and three-dimensionally the effect of resorbable collagen-based bone-filling material on periapical healing of endodontic lesions with four-wall defects following endodontic microsurgery (EMS).

METHODOLOGY

This parallel, randomized controlled superiority clinical trial involved 86 lesions with the strictly endodontic origin and four-wall defect morphology. EMS procedures were performed by calibrated postgraduate residents. Before flap closure, osteotomies were randomized to the control or treatment group. In the control group, the flap was repositioned with no material added. In the treatment group, a collagen-based bone-filling augmentation material was placed into the osteotomy. Clinical and radiographic examinations were completed after 12 months. Periapical healing was evaluated by blinded evaluators using periapical (PA) radiographs according to Molven's criteria and cone beam computed tomography (CBCT) scans according to PENN's 3D criteria. Cortical plate healing was scored according to the RAC/B index. The data were analysed using Fisher's exact test, Logistic regression models and Chi-squared test. The significance level was predetermined at p < .05.

RESULTS

Sixty-six cases were evaluated at the 12-month follow-up, with 30 and 36 cases in the control and treatment groups, respectively. Only the asymptomatic cases (control = 26, treatment = 32) were included in the radiographic evaluation. Twenty-three cases (88.5%) in the control and 28 (87.5%) cases in the treatment group demonstrated complete healing on PA radiographs (p = 1.000). On CBCT, 10 (38.4%) and 21 (65.6%) cases had completely healed in the control and treatment groups, respectively (p = .095). The re-establishment of the buccal cortical plate was detected in 12 (46.2%) and 22 (68.8%) cases in the control and treatment groups, respectively (p = .243).

CONCLUSION

Within the limitations of the present study, the use of collagen-based bone-filling material had no statistically significant effect on the periapical healing of endodontic lesions with four-wall defect following EMS at the 12-month follow-up when evaluated by PA radiographs or CBCT scans. However, the observed higher percentage of a re-established cortical plate in the treatment group could suggest a clinical benefit that is of interest after surgical endodontic treatment.

Resective and Regenerative Approach for an Unresolved Periapical Lesion: A Surgical Case Report With 24-Month Follow-Up

The pulp and the periodontium are inherently interconnected, both anatomically and functionally. Conditions affecting the periodontium and the pulp can create challenges in diagnosis, treatment strategizing, and predicting outcomes. This case report outlines the combination of resection and regeneration techniques utilizing mineral trioxide aggregate (MTA) and bone grafting to address a persistent periapical lesion in a maxillary premolar. The treatment led to the effective alleviation of the patient's symptoms and successful regeneration.

Clinical Outcome and Predictors of Endodontic Microsurgery Using Cone-beam Computed Tomography: A Retrospective Cohort Study

INTRODUCTION

The aim of this retrospective cohort study was to evaluate the clinical outcomes and identify the prognostic factors of endodontic microsurgery based on cone-beam computed tomographic (CBCT) scans.

METHODS

Patients who underwent endodontic microsurgery in teeth with asymptomatic apical periodontitis were included. The clinical outcomes were determined based on clinical and radiographic examinations after surgery 12-48 months. Radiographic healing was assessed on CBCT images by using the modified PENN 3-dimensional criteria and classified into 4 categories: complete, limited, uncertain, and unsatisfactory healing. Multivariate logistic regression was performed to detect outcome risk factors.

RESULTS

Of the 204 teeth in 173 invited patients, 148 teeth of 126 patients were examined at review. On CBCT images, 88 teeth (59.5%) showed complete healing, and 42 (28.4%) teeth showed limited healing. All these 130 teeth were asymptomatic and achieved a clinical success rate of 87.8%. Uncertain healing was observed in 9 teeth, one of which was symptomatic. The remaining 9 teeth were unsatisfactory healing on CBCT scans, including 6 teeth with clinical symptoms and 3 free. Lesion type and root-end filling quality were significant outcome predictors (P < .05). The risk of treatment failure for teeth with combined endodontic-periodontal lesions was 8.6 times higher than that for teeth with isolated endodontic lesions. Adequate root-end filling quality improved the probability of success by 5.3 times.

CONCLUSIONS

Based on CBCT data, an adequate performed endodontic microsurgery could have predictable success in teeth without periodontal involvement.

Volumetric evaluation of effects of platelet-rich fibrin and concentrated growth factor on early bone healing after endodontic microsurgery: a randomized controlled trial

BACKGROUND

This randomized controlled clinical trial compared the effects of platelet-rich fibrin (PRF) and concentrated growth factor (CGF) on early bone healing after endodontic microsurgery.

METHODS

Eighteen patients with an isolated periapical lesion < 10 mm in the maxillary anterior region were randomly assigned to three groups: control, PRF, or CGF. Endodontic microsurgery was performed and PRF or CGF membranes were placed over the bone defects in the experimental groups. The volume of the bone defect at postoperative one week, three months, and six months was evaluated using cone-beam computed tomography and Mimics software. The results were statistically analyzed using the Kruskal-Wallis test and post-hoc Mann-Whitney U test with Bonferroni correction.

RESULTS

At the three-month follow-up, the PRF and CGF groups showed significantly greater bone healing compared with the control group (p > 0.05). However, no significant difference was observed between the PRF and CGF groups. At the six-month follow-up, no significant differences were observed between the groups.

CONCLUSIONS

These results suggested that PRF and CGF promote early bone healing after endodontic microsurgery.

Treatment-Related Factors Affecting the Success of Endodontic Microsurgery and the Influence of GTR on Radiographic Healing-A Cone-Beam Computed Tomography Study

The primary objective of this retrospective study was to assess the correlation between treatment-related factors (resection angle, depth of retrograde filling, length of resected root and use of guided tissue regeneration-GTR) evaluated using cone-beam computed tomography (CBCT) scans and the treatment outcomes of endodontic microsurgery (EMS). The secondary purpose of this research was to evaluate the influence of the GTR technique on the radiographic healing state, taking into account the initial parameters of periapical lesions. In 161 cases, the local factors (volume of a lesion, bone destruction pattern, presence/absence of cortical bone destruction) were measured using preoperative CBCT images before undergoing EMS. At least one year after surgery, the outcome of EMS was classified as a success or a failure (based on radiographic and clinical criteria). Using postoperative CBCT, treatment-related factors (resection angle, depth of retrograde filling, and length of resected root) were measured. Additionally, the status of radiographic healing was evaluated (in accordance with modified PENN 3D criteria). Eighteen cases (11.18%) were classified as failures, and 143 were classified as successes (88.82%). Univariate analysis showed that there was no statistically significant influence of treatment-related factors on the healing outcome of EMS. An exact Fischer's test showed the significant impact of GTR on radiographic healing (P < 0.001) in apical lesions (P < 0.001), lesions with a volume between 100 mm3 and 450 mm3 (P < 0.009) and over 450 mm3 (P < 0.001), lesions with the destruction of one plate (P < 0.001), and lesions with the destruction of two plates (through and through) (P = 0.022). The use of GTR in apical lesions, lesions with volumes over 100 mm3, and lesions with the destruction of at least one plate is significantly associated with better radiographic healing.

Augmented Reality and 3-Dimensional Dynamic Navigation System Integration for Osteotomy and Root-end Resection

INTRODUCTION

Augmented reality (AR) superimposes high-definition computer-generated virtual content onto the existing environment, providing users with an enhanced perception of reality. This study investigates the feasibility of integrating an AR head-mounted device into a 3-dimensional dynamic navigation system (3D-DNS) for osteotomy and root-end resection (RER). It compares the accuracy and efficiency of AR + 3D-DNS to 3D-DNS for osteotomy and RER.

METHODS

Seventy-two tooth roots of 3D-printed surgical jaw models were divided into two groups: AR + 3D-DNS (n = 36) and 3D-DNS (n = 36). Cone-beam computed tomography scans were taken pre and postoperatively. The osteotomy and RER were virtually planned on X-guide software and delivered under 3D-DNS guidance. For the AR + 3D-DNS group, an AR head-mounted device (Microsoft HoloLens 2) was integrated into the 3D-DNS. The 2D- and 3D-deviations were calculated. The osteotomy and RER time and the number of procedural mishaps were recorded.

RESULTS

Osteotomy and RER were completed in all samples (72/72). AR + 3D-DNS was more accurate than 3D-DNS, showing lower 2D- and 3D-deviation values (P < .05). The AR + 3D-DNS was more efficient in time than 3D-DNS (P < .05). There was no significant difference in the number of mishaps (P > .05).

CONCLUSIONS

Within the limitations of this in vitro study, the integration of an AR head-mounted device to 3D-DNS is feasible for osteotomy and RER. AR improved the accuracy and time efficiency of 3D-DNS in osteotomy and RER. Head-mounted AR has the potential to be safely and reliably integrated into 3D-DNS for endodontic microsurgery.

Utility of Ultrasonography for Diagnosing and Differentiating Periapical Granuloma from Radicular Cyst

RATIONALE AND OBJECTIVES

This study aimed to investigate the reliability and accuracy of high-resolution ultrasonography (US) for diagnosing periapical lesions and differentiating radicular cysts from granulomas.

MATERIALS AND METHODS

This study included 109 teeth with periapical lesions of endodontic origin from 109 patients scheduled for apical microsurgery. Ultrasonic outcomes were analyzed and categorized after thorough clinical and radiographic examinations using US. B-mode US images reflected the echotexture, echogenicity, and lesion margin, while color Doppler US assessed the presence and features of blood flow of interested areas. Pathological tissue samples were obtained during apical microsurgery and subjected to histopathological examination. Fleiss' κ was used to measure interobserver reliability. Statistical analyses were performed to assess the diagnostic validity and the overall agreement between US and histological findings. The reliability of US compared to histopathological examinations was assessed based on Cohen's κ.

RESULTS

The percent accuracy of US for diagnosing cysts, granulomas, and cysts with infection based on histopathological findings was 89.9%, 89.0%, and 97.2%, respectively. The sensitivity of US diagnoses was 95.1% for cysts, 84.1% for granulomas, and 80.0% for cysts with infection. The specificity of US diagnoses was 86.8% for cysts, 95.7% for granulomas, and 98.1% for cysts with infection. The reliability for US compared to histopathological examinations was good (κ = 0.779).

CONCLUSION

The echotexture characteristics of lesions in US images correlated with their histopathological features. US can provide accurate information on the nature of periapical lesions based on the echotexture of their contents and the presence of vascularity. It can help improve clinical diagnosis and avoid overtreatment of patients with apical periodontitis.

Physicochemical, mechanical and biological properties of nano-calcium silicate-based cements: a systematic review

This systematic review evaluated the effects of nano-sized cement particles on the properties of calcium silicate-based cements (CSCs). Using defined keywords, a literature search was conducted to identify studies that investigated properties of nano-calcium silicate-based cements (NCSCs). A total of 17 studies fulfilled the inclusion criteria. Results indicated that NCSC formulations have favourable physical (setting time, pH and solubility), mechanical (push out bond strength, compressive strength and indentation hardness) and biological (bone regeneration and foreign body reaction) properties compared with commonly used CSCs. However, the characterization and verification for the nano-particle size of NCSCs were deficient in some studies. Furthermore, the nanosizing was not limited to the cement particles and a number of additives were present. In conclusion, the evidence available for the properties of CSC particles in the nano-range is deficient-such properties could be a result of additives which may have enhanced the properties of the material.

Effectiveness of root resection techniques compared with root canal retreatment or apical surgery for the treatment of apical periodontitis and tooth survival: A systematic review

BACKGROUND

To manage apical periodontitis in root filled maxillary and mandibular molars, root resection techniques may be employed to avoid the loss of the tooth.

OBJECTIVES

The objectives of the study were to systematically analyse the effectiveness of root resection techniques (root resection/crown resection/root amputation) for the management of apical periodontitis with non-surgical root canal retreatment or apical surgery by the evaluation of clinical and patient-related outcomes (PROMS), in human experimental studies and longitudinal studies.

METHODS

An electronic literature search in PubMed, MEDLINE via OVID interface, EMBASE and Cochrane Central, supplemented by a manual hand search of the grey literature, was performed up to 25th September 2021. Randomized controlled trials, comparative clinical trials and observational studies reporting on the outcome (tooth survival and patient-reported outcome measures with a minimum follow-up of 1 year) of root resection techniques for treating apical periodontitis were identified. The risk of bias was evaluated using the Newcastle-Ottawa scale.

RESULTS

From a total of 2098 reports, 36 were considered for further screening. Three retrospective studies, published between 2018 and 2020, were included in this systematic review. A high heterogeneity in terms of protocols, study design and the reported outcomes were observed. The risk of bias was scored as low to moderate. These three studies consisted of data from 305 resected teeth, from 254 patients, with a follow-up period of 1-16.8 years. Overall, 151 teeth were extracted during the follow-up period. In these studies, root resection treatment was carried out on 42 teeth exclusively for endodontic reasons. One of these studies reported 12 out of 23 teeth lost at follow-up. None of the studies reported on PROMS.

DISCUSSION

Although root resection techniques may be used for treating teeth with apical periodontitis, the data are limited. Furthermore, the studies are very heterogeneous and associated with high risk of bias.

CONCLUSIONS

Given the current level of available evidence, it is not possible to recommend, or dismiss, root resection techniques for managing apical periodontitis.

REGISTRATION

PROSPERO database (CRD42021260306).

New-designed 3D printed surgical guide promotes the accuracy of endodontic microsurgery: a study of 14 upper anterior teeth

We aimed to design a novel three-dimensional (3D) printed surgical guide and evaluate its accuracy in assisting endodontic microsurgeries. A new 3D printed surgical guide was designed by computer-aided design and computer-aided manufacturing (CAD/CAM) technology and applied to 7 patients who underwent endodontic microsurgeries of upper anterior teeth from 2020.01 to 2020.12 as the experimental group. 7 patients who suffered from endodontic microsurgeries operated by the same surgeon without using the surgical guide from 2019.01 to 2019.12 were selected as the control group. Cone beam computed tomography (CBCT) was performed more than 12 months after operation, and the accuracy of apical resection was compared between the two groups. The accuracy of the microsurgery focused on the length and angle of the root apical resection. In the study, CBCT data and oral digital scanning data were used to reconstruct 3D models of periapical lesions with soft and hard tissue information, based on which we designed the new 3D printed surgical guides. The guides were successfully applied to the apectomy in endodontic microsurgeries. The deviation of the apical resection length of the experimental group (0.467 ± 0.146 mm) was better than that of the control group (1.743 ± 0.122 mm) (P < 0.0001), and the deviation of the apical resection angle of the experimental group (9.711 ± 3.593°) was significantly less than that of the control group (22.400 ± 3.362°) (P < 0.0001). The 3D-printed surgical guide could effectively guide endodontic microsurgery and improve its accuracy by fixing both the position and the angle of apectomy. The new type of surgical guide could accurately localize the root apex and guide the apical resection.

Management of Apico-marginal Defects With Endodontic Microsurgery and Guided Tissue Regeneration: A Report of Thirteen Cases

The loss of periodontal tissue support and vertical buccal bone loss in apico-marginal defects can often be mistaken for features indicative of vertical root fractures and this study reports thirteen cases with persistent symptomatic apical periodontitis, apico-marginal defects, and large periapical lesions that were managed with endodontic microsurgery in conjunction with bone grafts and barrier placements with a follow-up period of up to 9 years. At the recall sessions, all cases were asymptomatic with radiographical success with only 2 cases exhibiting residual apical radiolucency, but with evident reduction in the lesion size, indicative of healing. This study highlights the potential of utilizing endodontic microsurgery combined with guided tissue regeneration that proved effective in stimulating the regeneration of periodontal tissue in cases of apico-marginal defects that can lead to favourable long-term outcomes.

Clinical and radiological outcomes of dynamic navigation in endodontic microsurgery: a prospective study

OBJECTIVES

This study was aimed at evaluating the clinical and radiological outcomes of novel dynamic navigation (DN)-aided endodontic microsurgery (EMS), with an analysis of potential prognostic factors.

MATERIALS AND METHODS

Forty-six teeth from 32 patients who received DN-aided EMS were included. Clinical and radiographic assessments were performed at least 1 year postoperatively. Two calibrated endodontists assessed radiological outcomes according to two-dimensional (2D) periapical radiography (PA) and three-dimensional (3D) cone-beam computed tomography (CBCT) imaging using Rud's and Molven's criteria and modified PENN 3D criteria, respectively. Fisher's exact test was used for statistical analysis of the predisposing factors.

RESULTS

Of the 32 patients with 46 treated teeth, 28 with 40 teeth were available for follow-up. Of the 28 patients, four (five teeth) refused to undergo CBCT and only underwent clinical and PA examinations, and the remaining 24 (35 teeth) underwent clinical, PA, and CBCT examinations. Combined clinical and radiographic data revealed a 95% (38/40) success rate in 2D healing evaluations and a 94.3% (33/35) success rate in 3D healing evaluations. No significant effect was found in sex, age, tooth type, arch type, preoperative lesion volume, preoperative maximum lesion size, presence/absence of crown and post, and the root canal filling state on the outcome of DN-aided EMS.

CONCLUSIONS

DN-aided EMS has a favorable prognosis and could be considered an effective and reliable treatment strategy. Further investigations with larger sample sizes are required to confirm these results.

CLINICAL RELEVANCE

DN-aided EMS could be considered an effective and reliable treatment strategy.

Comparison of Marginal Adaptation, Surface Hardness and Bond Strength of Resected and Retrofilled Calcium Silicate-based Cements Used in Endodontic Surgery: An In Vitro Study

AIMS

This study compared the effects of orthograde and retrograde methods on marginal adaptation, surface hardness, and push-out bond strength (POBS) of three calcium silicate-based used in endodontic surgery.

MATERIALS AND METHODS

Ninety single-rooted human mandibular premolars were randomly assigned into six groups (n = 15/group): groups I and II, ProRoot mineral trioxide aggregate (MTA) with orthograde and retrograde methods; groups III and IV, Biodentine (BD) with orthograde and retrograde methods; groups V and VI, iRoot BP Plus (BP-RPM) with orthograde and retrograde methods. After obturation, the apical 3 mm of each root was sectioned into two 1-mm-thick root slices and evaluated for marginal adaptation using a scanning electron microscope, surface hardness using Vickers hardness tester and POBS using a universal testing machine.

RESULTS

Orthograde placement had a higher maximum gap width than retrograde placement (p < 0.05), but there was no significant difference among the tested materials (p > 0.05). Biodentine exhibited lower surface hardness than ProRoot MTA and iRoot BP Plus (p < 0.05), but there was no significant difference between ProRoot MTA and iRoot BP Plus (p > 0.05). Orthograde placement had higher POBS compared with retrograde placement (p < 0.05). Biodentine had higher POBS than iRoot BP Plus (p < 0.05), but no significant difference from ProRoot MTA (p > 0.05). The failure mode was mainly mixed for all the tested materials regardless of material type or placement technique.

CONCLUSION

The retrograde method had better marginal adaptation; however, the orthograde method provided better dislodgement resistance. Biodentine had lower surface hardness than MTA and iRoot BP Plus with both techniques, whereas iRoot BP Plus demonstrated lower dislodging resistance than BD.

CLINICAL SIGNIFICANCE

The current findings suggest that orthograde technique, a simpler periapical surgery, with ProRoot MTA provides potentially better surface hardness and POBS than BD and iRoot BP Plus in single-canal teeth.

Unveiling Hidden Canals: Middle Mesial Canal Prevalence in Mandibular First Molars Using Cone-Beam Computed Tomography Analysis in Central India

Background The most frequent reason involving failure of root canal treatment in molar teeth is the inability to locate additional canals. While much research has been conducted on the morphology of mandibular molars, little is known about isthmuses and middle mesial (MM) canals in the Indian population. The primary aim of the present research was to determine the prevalence of MM canals and isthmuses of mandibular first molars in the Central India population using cone-beam computed tomography (CBCT) images. Methodology CBCT of 140 mandibular first molar teeth was analyzed from the institutional database images in the coronal, sagittal, and axial planes. Data concerning the number of root canals, the presence of middle mesial canals, and the presence of isthmus were noted. Information collected was transferred into an Excel sheet and analyzed using the Statistical Package for Social Sciences (IBM Corp., Armonk, NY, USA). Results Eight images (5.71%) revealed the presence of middle mesial canals with no statistically significant occurrence. The incidence of isthmi in the mandibular first molar was 84.3%, and the presence of isthmi in the coronal third was about 38.6%. This showed a considerable presence. Conclusion There is incidence of the middle mesial canal, which emphasizes the need to locate extra canals in patients undergoing root canal endodontic treatment. The implementation of CBCT will help identify the extra canal before the treatment. This will help ultimately in providing better patient care.

Outcome of intentional replantation of endodontically treated teeth with periapical pathosis: A systematic review and meta-analysis

The purpose of the present review was to examine success, survival and failure following intentional replantation of endodontically treated teeth with existing periapical pathosis and to determine the factors that might affect the outcome of replantation. Clinical trials, longitudinal studies, case series with >10 cases and at least 1-year follow-up were included. The average rate of success following intentional replantation was 77.23%. Meta-analysis revealed the mean weighted survival to be 85.9% (95% CI: 79.6-91.2) Common complications include inflammatory root resorption (0%-27%) and ankylosis (0%-25%). Variables influencing successful outcome include extra alveolar dry time <15 min; root-end resection (2-3 mm) and cavity preparation (3 mm); manipulation of the tooth using the crown only; and use of an appropriate storage media. The review concludes that intentional replantation is a viable treatment option with acceptable survival rates for endodontically treated teeth with periapical pathosis.

Conservative endodontic microsurgery to protect critical anatomical structures-selective curettage: a case series

BACKGROUND

Endodontic microsurgery has yielded highly successful outcomes in preserving teeth with persistent or recurrent cases of periapical periodontitis that could not be successfully treated by nonsurgical endodontic approaches. To avoid complications in conditions in which periapical lesions invade anatomical structures such as the nasopalatine nerve tube and mandibular canal, selective curettage has been proposed as an alternative choice of complete curettage in surgery.

CASE PRESENTATION

The 8 cases reported herein had undergone root canal treatment and/or retreatment but still presented with symptoms, such as recurring sinus tracts and persistent dull pain. The radiographic examination indicated a large area of radiolucency that was associated with the tooth and had invaded adjacent critical anatomical structures. The patients opted for selective curettage via endodontic microsurgery, and the lesions were histologically confirmed as periapical cysts or granulomas. The follow-up results for one year or more indicated that the affected teeth were clinically asymptomatic and exhibited complete or incomplete healing radiographically.

CONCLUSION

This case series provides clinical evidence for the feasibility of selective curettage in endodontic microsurgery, which can avoid complications caused by damage to the adjacent critical anatomical structures.

Management of Odontogenic Sinusitis: Results with Single-Step FESS and Dentoalveolar Surgery

OBJECTIVE

Odontogenic sinusitis (OS) is a well-known and important border of specialties in otorhinolaryngology and dentoalveolar surgery. Odontogenic sinusitis can develop due to iatrogenic harm or odontogenic infection. The gold standard diagnostic method is clinical and radiological-CBCT (cone beam computed tomography)-examination. The treatment of this condition requires collaboration between ENT and dentoalveolar surgery specialists and can be non-surgical or surgical based on staging. This paper aims to share the results of our clinical study whereby complex therapy was administered by a dentoalveolar surgeon and an otorhinolaryngologist in cooperation.

PATIENTS AND METHODS

We conducted a retrospective study comprising 111 OS patients who underwent complex therapy between 2016 and 2023 at Semmelweis University, Budapest, Hungary. All patients were treated with concurrent FESS (functional endoscopic sinus surgery) and dentoalveolar surgery. Follow-up was based on symptoms, clinical examination and CBCT imaging.

RESULTS

Of the 111 patients, 107 were successfully treated with concurrent FESS and dentoalveolar surgery, and only 4 had further symptoms following the complex therapy and needed retreatment.

CONCLUSIONS

The complex, single-session therapy involving FESS and oral surgery is an effective treatment method, which is less invasive and associated with fewer complications compared to previous interventions, such as the Luc-Caldwell procedure.

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.