The Buffalo study: Outcome and associated predictors in endodontic microsurgery- a cohort study

Two- and three-dimensional healing assessment after endodontic microsurgery in through-and-through periapical lesions: 5-year follow-up from a randomized controlled trial

AIM

To evaluate clinical and radiographic outcome of endodontic microsurgery in through-and-through periapical lesions at 1-year and 5-year follow-up with adjunct use of platelet-rich plasma (PRP).

METHODOLOGY

Thirty-two patients with large through-and-through periapical lesions were randomized in platelet-rich plasma (PRP) group and control group. Two-dimensional (2D) healing was evaluated with Molven's criteria and three-dimensional (3D) healing with modified PENN 3D criteria. Healing at resection plane (R), apical area (A), buccal cortex (BC), palatal cortex (PC) and overall bone healing (B) was assessed using CBCT scans. The volume of lesion was measured using ITK-Snap software. The analysis included comparison of 1- to 5-year intragroup (Friedman test/McNemar test) and intergroup scoring (Chi-square/ Mann-Whitney test). Logistic regression analysis was performed to determine the effect of various factors on healing at 5 years.

RESULTS

Out of 32 patients/59 teeth evaluated after 1-year of endodontic microsurgery, 24 patients/44 teeth reported at 5 - year follow-up. Healing assessment with modified PENN 3D criteria revealed improvement in overall success rate of 66.7% at 1 year to 83.3% at 5 years, with no deterioration in any healing category. PRP group exhibited significantly better 3D healing than control group; both at 1 year (84.6% vs. 45.5%) and 5 years (100% vs. 63.6%). A significantly higher number of completely healed teeth were observed in PRP group than the control group at 5 years with respect to R, BC and B parameters. A volume reduction of 88% (91.4% PRP, 84% control) was depicted at 1 year and 94% (97.1% PRP, 91.1% control) at 5 years. None of the recorded factors including age, gender, size of lesion, preoperative swelling and sinus, histology of lesion, use of PRP, tooth location, preoperative buccal bone had significant effect on 3D healing at 5 years.

CONCLUSIONS

This 5-year study suggested improvement in 3D radiographic healing of large through-and-through periapical lesions from 1 to 5 years with no deterioration in any healing parameter in both control and PRP groups. The additional use of PRP led to significantly better healing in such lesions. RACB index using CBCT allows better estimation of healing at resected, apical and cortical plane over modified PENN 3D or Molven's criteria.

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 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.

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).

Clinical outcomes of endodontic microsurgery in complicated cases with large or through-and-through lesions: a retrospective longitudinal study

OBJECTIVES

To investigate the clinical outcomes of endodontic microsurgery in complicated cases presenting with large or through-and-through lesions.

MATERIALS AND METHODS

We retrospectively collected and analyzed preoperative, intraoperative, and follow-up data from 143 complicated cases that underwent endodontic microsurgery. Clinical outcomes were assessed in terms of tooth survival and surgery success. Cox regression analysis was used to evaluate the survival rate and identify associated risk factors. Additionally, the success rate was compared across different postoperative periods, and potential factors contributing to surgical failure were identified through binary logistic regression.

RESULTS

The overall survival and success rates were 93.0% and 91.7%, respectively. The Cox regression model identified four risk factors affecting tooth survival, including apicoectomy of four teeth (HR = 35.488; P = 0.0002), an open apex observed on preoperative radiographs (HR = 6.300; P = 0.025), the performance of guided tissue regeneration technique (HR = 8.846; P = 0.028), and a palatal surgical approach (HR = 8.685; P = 0.030). The success rate demonstrated an initial increase in the early postoperative period (from 0.5 to 2 years; P = 5.8124e-30), followed by stabilization (from 2 to 9 years; P = 0.298). Surgery success rate significantly declined when apicoectomy involved four teeth (OR = 109.412; P = 0.002).

CONCLUSIONS

Endodontic microsurgery demonstrates satisfactory outcomes in complicated cases, maintaining a stable success rate after two years. However, tooth survival and surgery success are significantly compromised when apicoectomy involves four teeth. Factors such as guided tissue regeneration, an open apex, and the palatal surgical approach are associated with an increased risk of tooth extraction.

CLINICAL RELEVANCE

Despite achieving acceptable outcomes in complicated cases, endodontic microsurgery is adversely affected by the apicoectomy of four teeth.

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.

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.

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.

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.

Treatment of an ossifying fibroma of the mandible with endodontic microsurgery and grafting with a biphasic calcium sulfate material: a case report

A significant percentage of lesions of endodontic origin require surgical management due to the possible diagnosis of odontogenic cysts and tumors in the maxilla and mandible. Ossifying fibroma is a benign fibro-osseous lesion that typically presents as a painless, slow-growing, and expansile lesion that appears as a well-demarcated lesion with a variable degree of internal calcification on radiography. Treatment results in a large osseous defect, utilization of a graft to fill the void accelerates healing and prevents complications that may result from failure to fill by the host response.

CASE PRESENTATION

Following endodontic surgery placement of osseous graft material via Guided Tissue Regeneration to fill the defect aids to accelerate fill of the defect on a healthy 26-year-old female patient. A case discussing the one-step treatment of an ossifying fibroma of the anterior part of the mandible following endodontic microsurgery with associated retrograde fill of the apex, then site grating with biphasic calcium sulfate (Bond Apatite®) used in regeneration of the osseous defect related to the lesion and resulting surgery.

CLINICAL DISCUSSION

Histologically, the ossifying fibroma is dominated by connective tissue containing cell rich areas with a few fragments of fibrosis. Moreover, in the connective tissue numerous small fragments of spongy and compact bone with areas of partial necrosis present and a significant number of inflammatory cells are observed. Surgical removal of the cyst with thorough curettage of the osseous walls and grafting of the defect provides predictable healing and the desired clinical results sought. Utilization of the biphasic calcium sulfate graft material allows the elimination of the need to overlay the area with a membrane before the flap due to its hard set and the prevention of soft tissue ingrowth into the graft material during the healing phase. Additionally, the hard set of the material allows tenting of the area to maintain the desired volume and ridge contour. Conversion of the graft material depending on the volume placed to host bone occurs over a 3-6 month period.

CONCLUSION

The case report presented, as well as the authors experience mimics the literature on biphasic calcium sulfate in its use as an osseous graft material and is an effective method for the repair of osseous defects that result from the removal of tumors and cysts of the maxilla and mandible. Treatment of an ossifying fibroma is an ideal application of the use of this biphasic calcium sulfate material allowing tenting of the surgical site over the defect created after cyst removal without the need for resorbable collagen membranes. This simplifies its use and decreases material costs that may hamper patient acceptance of treatment without a decrease in expected clinical results.

Outcome of non-surgical root canal retreatment procedures obturated with warm gutta-percha techniques: A longitudinal clinical study

OBJECTIVE

To evaluate the success rate of non-surgical root canal retreatment at the 2- to 3-year follow-up and identify the possible prognostic factors.

METHODS

Patients who underwent root canal retreatment at a university dental clinic were contacted for clinical and radiographic follow-up. The retreatment outcomes in these cases were based on clinical signs, symptoms, and radiographic criteria. Inter- and intra-examiner concordance were calculated using Cohen's kappa coefficient. The retreatment outcome was dichotomized into success or failure according to strict and loose criteria. The radiographic success criteria consisted of complete resolution or absence of a periapical lesion (strict criteria) or a reduction in the size of an existing periapical lesion at recall (loose criteria). χ² tests were used to evaluate possible variables associated with retreatment outcomes (age, sex, tooth type, location, contact points, periapical status, quality of previous and final root canal filling, previous and final restoration, number of visits, and complications).

RESULTS

Overall, 129 teeth (113 patients) were included in the final evaluation. The success rate was 80.6% under strict criteria and 93% under loose criteria. Molars, teeth with an initially higher periapical index (PAI) score, and teeth with > 5 mm periapical radiolucency had a lower success rate according to the strict criteria model (p < 0.05). When the loose success criteria were used, teeth with larger (> 5 mm) periapical lesions and those that had been perforated during retreatment showed a lower success rate (p < 0.05).

CONCLUSIONS

The present study demonstrated that non-surgical root canal retreatment is a highly successful procedure after an observation period of 2-3 years. Treatment success is primarily affected by the presence of periapical lesions.

Guided tissue regeneration in class IV external cervical resorption: A case report

External cervical resorption (ECR) is a type of dental resorption that originates from the loss of the cementum's protective layer. The direct exposure of dentin to the periodontal ligament may lead to the invasion of clastic cells through an entry point on the external root surface into the dentinal tissue, causing resorption. Depending on the extension of ECR, different treatments are proposed. Although the literature presents distinct materials and methods for restoring ECR areas, an existing gap is related to care in the treatment of the supporting periodontal tissue. Guided tissue regeneration/guided bone regeneration (GTR/GBR) includes the stimulation of bone formation in bone defects using different types of membranes (resorbable and non-resorbable), regardless of its association with bone substitutes or grafts. Despite the benefits of guided bone regeneration, the application of this method in cases of ECR is still under-explored in the literature. Thus, the present case report uses GTR with xenogenic material and polydioxanone (PDO) membrane in a case of class IV ECR. The success of the present case is related to the correct diagnosis and treatment plan. Complete debridement of resorption areas and restoration with biodentine were effective in tooth repair. GTR contributed to the stabilization of supporting periodontal tissues. The association of the xenogeneic bone graft with the PDO membrane proved to be a viable option for restoring the health of the periodontium.

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.

Predicting case difficulty in endodontic microsurgery using machine learning algorithms

OBJECTIVES

The study aimed to develop and validate machine learning models for case difficulty prediction in endodontic microsurgery, assisting clinicians in preoperative analysis.

METHODS

The cone-beam computed tomographic images were collected from 261 patients with 341 teeth and used for radiographic examination and measurement. Through linear regression (LR), support vector regression (SVR), and extreme gradient boosting (XGBoost) algorithms, four models were established according to different loss functions, including the L1-loss LR model, L2-loss LR model, SVR model and XGBoost model. Five-fold cross-validation was applied in model training and validation. Explained variance score (EVS), coefficient of determination (R²), mean absolute error (MAE), mean squared error (MSE) and median absolute error (MedAE) were calculated to evaluate the prediction performance.

RESULTS

The MAE, MSE and MedAE values ​​of the XGBoost model were the lowest, which were 0.1010, 0.0391 and 0.0235, respectively. The EVS and R² values ​​of the XGBoost model were the highest, which were 0.7885 and 0.7967, respectively. The factors used to predict the case difficulty in endodontic microsurgery were ordered according to their relative importance, including lesion size, the distance between apex and adjacent important anatomical structures, root filling density, root apex diameter, root resorption, tooth type, tooth length, root filling length, root canal curvature and the number of root canals.

CONCLUSIONS

The XGBoost model outperformed the LR and SVR models on all evaluation metrics, which can assist clinicians in preoperative analysis. The relative feature importance provides a reference to develop the scoring system for case difficulty assessment in endodontic microsurgery.

CLINICAL SIGNIFICANCE

Preoperative case assessment is a crucial step to identify potential risks and make referral decisions. Machine learning models for case difficulty prediction in endodontic microsurgery can assist clinicians in preoperative analysis efficiently and accurately.

Do the Mechanical Properties of Calcium-Silicate-Based Cements Influence the Stress Distribution of Different Retrograde Cavity Preparations?

The aim of the present study was to investigate the influence of the mechanical properties of three different calcium-silicate-based cements on the stress distribution of three different retrograde cavity preparations. Biodentine™ "BD", MTA Biorep "BR", and Well-Root™ PT "WR" were used. The compression strengths of ten cylindrical samples of each material were tested. The porosity of each cement was investigated by using micro-computed X-ray tomography. Finite element analysis (FEA) was used to simulate three retrograde conical cavity preparations with an apical diameter of 1 mm (Tip I), 1.4 mm (Tip II), and 1.8 mm (Tip III) after an apical 3 mm resection. BR demonstrated the lowest compression strength values (17.6 ± 5.5 MPa) and porosity percentages (0.57 ± 0.14%) compared to BD (80 ± 17 MPa-1.22 ± 0.31%) and WR (90 ± 22 MPa-1.93 ± 0.12%) (p < 0.05). FEA demonstrated that the larger cavity preparation demonstrated higher stress distribution in the root whereas stiffer cement demonstrated lower stress in the root but higher stress in the material. We can conclude that a respected root end preparation associated with cement with good stiffness could offer optimal endodontic microsurgery. Further studies are needed to define the adapted cavity diameter and cement stiffness in order to have optimal mechanical resistance with less stress distribution in the root.

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.

Buccal plate thickness as a predictor for endodontic microsurgery outcomes: A retrospective cohort study

OBJECTIVE

The aim of the study was to determine the relationship between preoperative buccal plate thickness (BPT) and radiographic healing at the osteotomy site after endodontic microsurgery (EMS) with and without guided tissue regeneration (GTR) using cone beam computed tomography (CBCT) imaging.

STUDY DESIGN

The retrospective sample of 143 individuals who had EMS with pre- and postoperative CBCT scans available were divided into 2 groups: group 1 (GTR) and group 2 (no GTR), which were further divided into teeth where BPT was >1.0 mm or ≤1.0 mm. Bone healing was assessed by subjective evaluation of bone formation at the resected root surface (I₁), periapical bone formation (I₂), cortical plate formation (I₃), and a derived index (Author2-Author1 Indices) (I₄), calculated by a composite score of I₁ and I₂.

RESULTS

There was no significant impact on surgical healing with the use of GTR when BPT is >1.0 mm. The GTR had a significant impact on surgical healing when the BPT was ≤1.0 mm.

CONCLUSIONS

This study supported the use of CBCT to evaluate three-dimensional healing after EMS. The Author2-Author1 index was found to be a clinically relevant method for assessing healing. To improve healing rate, the EMS cases with a preoperative BPT of ≤1.0 mm may benefit from GTR.

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.

Patient-centric outcome assessment of endodontic microsurgery using periapical radiography versus cone beam computed tomography: A randomized clinical trial

AIM

This study aimed to evaluate whether utilizing additional cone beam computed tomography (CBCT) imaging has any effect on quality of life and healing outcome following periapical surgery compared with periapical radiographs (PR).

METHODOLOGY

The study was registered in ClinicalTrials.gov (NCT04333940). In this parallel group randomized controlled trial, 52 patients (88 teeth) with persistent apical periodontitis and periapical radiographic evidence of periapical lesion were randomly assigned to either PR or CBCT group. The primary predictor was the type of the imaging method (PR only or with additional CBCT). The primary outcome was patient's quality of life during the first week after periapical surgery and the secondary outcomes were duration of surgery and healing outcome at 12-month follow-up. Participants of both groups received periapical surgery based on the pre-surgical plan provided by the radiographic imaging methods. Quality of life (QoL) was assessed using Modified Shugars questionnaire. Radiographic analysis for healing was conducted using Molven's criteria and modified PENN 3D criteria. The categorical data between groups were analysed using the Chi-square test, whilst intragroup comparisons were analysed using the McNemar test. The average scores for each component of QoL (oral functions, general functions, pain, swelling and other symptoms), combined QoL scores (overall average of values of 13 variables) and analgesic usage on each day were calculated and analysed.

RESULTS

At 12 months of follow-up, fifty patients were evaluated. Participants in PR group reported significantly more swelling on first three days compared with CBCT group. The analgesic use was higher in the PR group on 2nd and 3rd day (Mann-Whitney U test with Bonferroni correction; p < .007). A significant difference in the limitation of general functions was observed at the second day (p < .07) with the higher values in the PR group. The combined QoL score between the two groups was found to be non-significant. However, none of the patients experienced intraoperative complications or neurovascular exposure. The mean surgical time was lesser in the CBCT group (p < .05). Radiographic healing revealed a success rate of 96.2% for the PR group and 95.8% for the CBCT group with no significant difference between the groups.

CONCLUSION

Participants in the CBCT group experienced substantially less early postoperative swelling and limitation in general functions, in comparison with the PR group. However, preoperative CBCT had no effect on other QoL parameters and intraoperative complications in medium-risk patients. Furthermore, CBCT did not exhibit any added advantage over periapical radiography in terms of assessing healing outcome following endodontic microsurgery. CBCT offered surgically relevant anatomic information for pre-surgical planning and ensured the treatment rendition with a significantly reduced operative time.

Treatment of a large through and through periapical lesion using guided tissue regeneration: A case report of 2 years follow-up

Proper removal of the diseased tissue, debriding the canal system, and sealing the defect or cavity, the surgeon prevents or reduces the spread of microorganisms within the periradicular tissues. Treatment modalities following the failure of root canal treatment (RCT) are root canal retreatment (ReRCT). Regeneration of periapical defects may have a significant problem in periradicular surgery. In such circumstances, the gingival connective tissue can proliferate, or the oral epithelium can migrate into the defect, preventing the development of normal trabecular bone. Hard tissue can be restored using guided tissue regeneration (GTR) in conjunction with endodontic treatment for endodontic-periodontal lesions. Treatment of large periapical defects using GTR increases overall treatment success.

Multifactorial Analysis of Endodontic Microsurgery Using Finite Element Models

Background: The present study aimed to classify the relative contributions of four biomechanical factors—the root-end filling material, the apical preparation, the root resection length, and the bone height—on the root stresses of the resected premolar. Methods: A design of experiments approach based on a defined subset of factor combinations was conducted to calculate the influence of each factor and their interactions. Sixteen finite element models were created and analyzed using the von Mises stress criterion. The robustness of the design of experiments was evaluated with nine supplementary models. Results: The current study showed that the factors preparation and bone height had a high influence on root stresses. However, it also revealed that nearly half of the biomechanical impact was missed without considering interactions between factors, particularly between resection and preparation. Conclusions: Design of experiments appears to be a valuable strategy to classify the contributions of biomechanical factors related to endodontics. Imagining all possible interactions and their clinical impact is difficult and can require relying on one’s own experience. This study proposed a statistical method to quantify the mechanical risk when planning apicoectomy. A perspective could be to integrate the equation defined herein in future software to support decision-making.

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.

Machine learning models for prognosis prediction in endodontic microsurgery

OBJECTIVES

This study aimed to establish and validate machine learning models for prognosis prediction in endodontic microsurgery, avoiding treatment failure and supporting clinical decision-making.

METHODS

A total of 234 teeth from 178 patients were included in this study. We developed gradient boosting machine (GBM) and random forest (RF) models. For each model, 80% of the data were randomly selected for the training set and the remaining 20% were used as the test set. A stratified 5-fold cross-validation approach was used in model training and testing. Correlation analysis and importance ranking were conducted for feature selection. The predictive accuracy, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), F1 score, and the area under the curve (AUC) of receiver operating characteristic (ROC) curves were calculated to evaluate the predictive performance.

RESULTS

There were eight important predictors, including tooth type, lesion size, type of bone defect, root filling density, root filling length, apical extension of post, age, and sex. For the GBM model, the predictive accuracy was 0.80, with a sensitivity of 0.92, specificity of 0.71, PPV of 0.71, NPV of 0.92, F1 of 0.80/0.80, and AUC of 0.88. For the RF model, the accuracy was 0.80, with a sensitivity of 0.85, specificity of 0.76, PPV of 0.73, NPV of 0.87, F1 of 0.79/0.81, and AUC of 0.83.

CONCLUSIONS

The trained models were developed by eight common variables, showing the potential ability to predict the prognosis of endodontic microsurgery. The GBM model outperformed the RF model slightly on our dataset.

CLINICAL SIGNIFICANCE

Clinicians can use machine learning models for preoperative analysis in endodontic microsurgery. The models are expected to improve the efficiency of clinical decision-making and assist in clinician-patient communication.

Impact of Periodontal Attachment Loss on the Outcome of Endodontic Microsurgery: A Systematic Review and Meta-Analysis

Background and Objectives: Endodontic microsurgery (EMS) aims to eradicate the sources of infection once the apical root resection removes most of the infected anatomical structures and repairs potential procedural errors in the apical region. An endodontic-periodontal lesion yields a pathological communication between the pulp and the periodontium. The purpose of this systematic review and meta-analysis is to evaluate the impact of periodontal attachment loss on the outcome of teeth submitted to EMS. Materials and Methods: PRISMA guidelines were followed. An electronic search was performed in EBSCOhost, Embase and PubMed databases with the following search key: (“endodontic microsurgery” AND “outcome”). No filters were used concerning the year of publication or language. Only randomized clinical trials, prospective and retrospective clinical studies in humans, with a minimum one-year follow-up, defined clinical and radiographic outcome criteria and estimable success rate for endodontic-periodontal lesion were included. Statistical analysis was performed using OpenMeta[Analyst] software. Results: Of a total of 113 articles, 34 were selected for full-text reading after duplicates deletion and title and abstract analysis. Thirteen and six studies were included in the systematic review and meta-analysis, respectively. A total of 2775 pooled teeth were submitted to EMS, of which 492 teeth and 4 roots had periodontal involvement. According to the qualitative analysis, success rates of the endodontic-periodontal group ranged from 67.6% to 88.2%. Meta-analysis revealed that the absence of periodontal attachment loss was predictive of a higher likelihood of success with an odds ratio of 3.14. Conclusions: Periodontal attachment loss presents a risk factor for EMS outcome. Although endodontic-periodontal lesions were associated with lower success rates considering a 1 to 10 years follow-up period, long-term successful prognosis following EMS has been reported, therefore presenting a fully valid and viable therapeutic option for the management of this type of lesions.