Clinician-centered Outcomes Assessment of Retreatment and Endodontic Microsurgery Using Cone-beam Computed Tomographic Volumetric Analysis

Introduction

Outcomes assessment of retreatment and endodontic microsurgery (EMS) are traditionally based on clinical findings and radiographs. The purpose of this study was to assess the volumetric change of periapical radiolucencies (PARLs) by cone-beam computed tomographic (CBCT)-based analysis in retreatment and EMS cases.

The Influence of Cone Beam Computed Tomography-Derived 3D-Printed Models on Endodontic Microsurgical Treatment Planning and Confidence of the Operator

IntroductionCurrently, there are no studies evaluating the impact of 3-dimensional (3D) printed models on endodontic surgical treatment planning. The aims of this study were: 1) to determine if 3D models could influence treatment planning; and 2) to assess the effect of 3D supported planning on operator confidence.MaterialsEndodontic practitioners (n = 25) were asked to analyze a preselected cone beam computed tomography (CBCT) scan of an endodontic surgical case and answer a questionnaire that elucidated their surgical approach. After 30 days, the same participants were asked to analyze the same CBCT scan. Additionally, participants were asked to study and to perform a mock osteotomy on a 3D printed model. The participants responded to the same questionnaire along with a new set of questions. Responses were statistically analyzed using chi square test followed by either logistic or ordered regression analysis. Adjustment for multiple comparison analysis was done using a Bonferroni correction. Statistical significance was set at ≤0.005.ResultsThe availability of both the 3D printed model and the CBCT scan resulted in statistically significant differences in the participants' responses to their ability to detect bone landmarks, predict the location of osteotomy, and to determine the following: size of osteotomy, angle of instrumentation, involvement of critical structures in flap reflection and involvement of vital structures during curettage. In addition, the participants’ confidence in performing surgery was found to be significantly higher.ConclusionsThe availability of 3D printed models did not alter the participants’ surgical approach but it significantly improved their confidence for endodontic microsurgery.     

Applications of Piezoelectric Surgery in Endodontic Surgery: A Literature Review

Introduction

Piezosurgery (piezoelectric bone surgery) devices were developed to cut bone atraumatically using ultrasonic vibrations and to provide an alternative to the mechanical and electrical instruments used in conventional oral surgery. Indications for piezosurgery are increasing in oral and maxillofacial surgery, as in other disciplines, such as endodontic surgery. Key features of piezosurgery instruments include their ability to selectively cut bone without damaging adjacent soft tissue, to provide a clear operative field, and to cut without generating heat. Although piezosurgery instruments can be used at most stages of endodontic surgery (osteotomy, root-end resection, and root-end preparation), no published data are available on the effect of piezosurgery on the outcomes of endodontic surgery. To our knowledge, no study has evaluated the effect of piezosurgery on root-end resection, and only 1 has investigated root-end morphology after retrograde cavity preparation using piezosurgery.

Methods

We conducted a search of the PubMed and Cochrane databases using appropriate terms and keywords related to the use and applications of piezoelectric surgery in endodontic surgery. A hand search also was conducted of issues published in the preceding 2 years of several journals. Two independent reviewers obtained and analyzed the full texts of the selected articles.

Results

A total of 121 articles published between January 2000 and December 2013 were identified. This review summarizes the operating principles of piezoelectric devices and outlines the applications of piezosurgery in endodontic surgery using clinical examples.

Conclusions

Piezosurgery is a promising technical modality with applications in several aspects of endodontic surgery, but further studies are necessary to determine the influence of piezosurgery on root-end resection and root-end preparation.     

A Clinical Evaluation of Cone-beam Computed Tomography: Implications for Endodontic Microsurgery

IntroductionCone-beam computed tomographic (CBCT) imaging is a valuable diagnostic tool for endodontics. Some studies report that CBCT images have limitations in representing the true clinical presentation. This prospective, in vivo study compared limited field of view (LFOV) CBCT measurements with clinical measurements made during endodontic surgery.MethodsEighty-seven subjects requiring endodontic surgery and LFOV CBCT acquisition of the surgical site were enrolled. Data collection involved clinicians answering standardized questions during the radiographic and surgical assessment. Intraoperatively, data were collected and photographically documented. Postoperatively, CBCT scans were evaluated by 3 calibrated, board-certified specialists: 2 endodontists and 1 oral and maxillofacial radiologist. The 2 subsets of data were compared through statistical analysis to quantify their relationship.ResultsThe subjects included 65 maxillary and 29 mandibular teeth from 87 subjects: 25 women and 62 men with an average age of 42 years old. The CBCT evaluators correctly identified the presence or absence of buccal plate fenestrations with 91.0% accuracy (95% confidence interval, 83.1–96.0) with 89.4% sensitivity and 92.9% specificity. The area of fenestrations measured clinically (mean = 19.6 ± 33.4 mm²) was generally larger than the area measured by CBCT imaging (mean across CBCT evaluators = 12.2 ± 19.1 mm²). Fenestration size in the maxillary arch was more likely to be underestimated than in the mandibular arch (P < .0001). Vertical bone height was also underestimated when measured on CBCT imaging.ConclusionsBased on the findings of this study, LFOV CBCT imaging accurately identifies the presence or absence of buccal plate fenestrations, yet, when a fenestration is present, underestimates its area.     

The Influence of Bone Tissue Deficiency on the Outcome of Endodontic Microsurgery: A Prospective Study

IntroductionThis study assessed the influence of deficiencies of the periapical and marginal bone tissue on clinical outcomes after endodontic microsurgery.MethodsData were collected from the Microscope Center of the Department of Conservative Dentistry at the Dental College of Yonsei University, Seoul, South Korea, between August 2004 and March 2011. In total, 199 teeth that required endodontic surgery were included in the study. During the surgical procedure, deficiencies of the periapical and marginal bone tissue were measured immediately before the flap was repositioned. The patients were recalled 6 months and 1 year after the surgical procedure to assess the clinical and radiographic signs of healing. The Student's t test or the Mann-Whitney U test and logistic regression were performed to evaluate the parameters. Significant associations between the outcome and all the evaluation parameters were analyzed using the Pearson chi-square test or the Fisher's exact test with a significance level of 0.05.ResultsA recall rate of 67.8% (135/199 teeth) was obtained. The height of the buccal bone plate was the only significant predictor (P = .040) of the healing outcome, suggesting that teeth with a buccal bone plate >3 mm presented a higher success rate than teeth with a buccal bone plate that was ≤3 mm high (94.3% vs 68.8%, P < .001).ConclusionsThese data suggest that a favorable prognosis can be expected when teeth are covered with a buccal bone plate that is >3 mm in height regardless of the amount of marginal bone loss.     

Non-Hodgkin Lymphoma Mimicking Endodontic Lesion: A Case Report with 3-dimensional Analysis,Segmentation, and Printing

Non-Hodgkin lymphoma (NHL) of the oral cavity can present with pain, swelling and radiolucent lesion mimicking endodontic diseases. This article reports on a case of diffuse large B-cell lymphoma initially diagnosed and treated as periodontal disease and then endodontic disease in the maxillary anterior and premolar area of a 40-year old female. A cone beam computed tomography (CBCT) image of the lesion was taken. The lesion was segmented using Mimics software (Materialise NV, Lueven, Belgium). Three-dimensional models of the tumor were printed. During the surgical phase teeth #4, 6, and 7 were extracted and biopsy samples were obtained. Histopathologic examination showed invasive sheets of large, atypical, basophilic cells strongly and diffusely positive for CD20. Three-dimensional analysis, segmentation, and printing of radiolucent lesions of the jaws assists with differential diagnosis and efficient treatment. Oral health professionals can play a crucial role in the early detection and diagnosis of oral NHL, thereby preventing extensive loss of function and esthetics, and even saving lives.     

CBCT头颅侧位片在头影测量中可重复性的研究

目的：比较锥形束CT（CBCT）三维头影测量与CBCT转化头颅侧位片（Cephalogram from CBCT,CCB）及数字化X线头颅侧位片（Digital Cephalogram,DC）头影测量的可重复性和可靠性。方法：对一名成年人进行CBCT扫描并拍摄数字化X线头颅侧位片。使用Invivo Dental 5．0软件对CBCT图像进行三维测量;CCB和DC采用Winceph 8．0软件进行二维头影测量。选择常用测量项目15项,同一操作者对3种图像测量15次。对CBCT,CCB及DC测量可重复性进行统计学分析,三者间可重复性差异采用方差分析。结果：CCB测量可重复性优于CBCT和DC（P＜0．05）。15个测量项目中CCB有8个测量项目精确度明显高于CBCT和DC。结论：CBCT三维影像能真实反映颅颌面空间结构,弥补二维图像失真,解剖结构重叠的不足。 CCB测量可重复性优于CBCT三维测量和传统X线头颅侧位片二维测量,在三维测量系统完善前,CCB是头影测量由二维向三维过度的重要测量方法。     

Distance and Bone Density between the Root Apex and the Mandibular Canal: A Cone-beam Study of 9202 Roots from a Brazilian Population

Introduction

Accidental damage to the inferior alveolar nerve is of concern during endodontic treatment of the posterior mandible teeth, and a careful evaluation of the relationship between the apices and the mandibular canal (MC) is mandatory to prevent iatrogenic complications. This study aimed to assess the distance between the root apices of posterior teeth and the MC and the bone density in such areas.

Management of Root Fenestration Using Buccal Decortication and Guided Tissue Regeneration: A Case Report and 3-dimensional Analysis

The management of patients with apical fenestration and clinical symptoms has always been limited to apical root resection and placement of the root tip within the bony crypt. This result would often present resolution of clinical symptoms based on a few case studies. In this case report, we present a case in which apical resection alone did not resolve the patient’s discomfort; on the contrary, it resulted in further bone loss and persistence of clinical symptoms. A corrective surgery was performed with the use of guided bone regeneration in conjunction with decortication of the cortical plate to induce bleeding. The patient symptoms resolved within a few weeks after the surgery, and the follow-up scan showed apical root coverage. Three-dimensional analysis was performed to compare the bony changes between the 2 surgeries and showed a significant amount of bone gain of around 200 mm³ and a 2-mm linear bone gain opposite the distobuccal root. The case presents a conservative approach to manage root fenestration of the buccal plate without further compromising the root apex.     

Effect of Field of View and Voxel Size on CBCT-Based Accuracy of Dynamic Navigation in Endodontic Microsurgery: An In Vitro Study

IntroductionThis study aimed to evaluate the influence of field of view (FOV) and voxel size on the accuracy of dynamic navigation (DN)–assisted endodontic microsurgery (EMS).MethodsNine sets of maxillary and mandibular 3-dimensional–printed jaw models composed of 180 teeth were divided into 9 groups with different FOVs (80 × 80 mm, 60 × 60 mm, and 40 × 40 mm) and voxel sizes (0.3 mm, 0.16 mm, and 0.08 mm). The endodontic DN system was used to plan and execute the EMS. The accuracy of the DN-EMS was represented by the platform deviation, end deviation, angular deviation, resection angle, and resection length deviation. Statistical analyses were performed using SPSS 24.0, and the significance level was set at P < .05.ResultsThe average platform deviation, end deviation, angular deviation, resection angle, and resection length deviation were 0.69 ± 0.31 mm, 0.93 ± 0.44 mm, 3.47 ± 1.80°, 2.35 ± 1.76°, and 0.41 ± 0.29 mm, respectively. No statistically significant differences in accuracy were observed between the nine FOV and voxel size groups.ConclusionsFOV and voxel size did not appear to play an important role in the accuracy of DN-EMS. Considering the image quality and radiation dose, it is reasonable to select a limited FOV (such as 40 × 40 mm and 60 × 60 mm) to cover only the registration device, involved teeth, and periapical lesion. The voxel size should be selected according to the required resolution and cone-beam computed tomography units.     

CBCT三维测量与CBCT转化头颅侧位片测量常用线距值比较

目的：比较头影测量常用线距值的锥形束CT（CBCT）三维测量与CBCT数据转化成头颅侧位片（CephalogramfromCBCT,CCB）的二维测量。方法：收集口腔正畸患者40名（男16名,女24名）进行CBCT扫描。操作者分别应用Invivo Dental 5．0三维测量软件和Winceph8．0软件对CBCT头颅数据和CCB进行测量,每个数据重复测量2次,取平均值。选择18项头影测量常用线距值,将两种方法测得数据进行统计学分析,采用配对t检验。结果：两种测量方法得出头影测量值中Me—G0,N—Me,N—Gn,ANS—Gn,Go—Pog,Pog—NB,LLL值差异有统计学意义（P〈0．05）;其余项目测量值无统计学意义（P〉0．05）。结论：CBCT的三维测量与Winceph8．0二维测量得出的常用线距值大部分无统计学差异,虽不能说明三维测量比转化后的二维测量更精确,但随着CBCT的应用及三维软件技术的进步,直接在CBCT数据上的三维测量能够代替传统的二维头影测量方法应用于临床。     

Comparison of Mineral Trioxide Aggregate and iRoot BP Plus Root Repair Material as Root-end Filling Materials in Endodontic Microsurgery: A Prospective Randomized Controlled Study

Introduction

This prospective randomized controlled study evaluated the clinical and radiographic outcome of endodontic microsurgery when using iRoot BP Plus Root Repair Material (BP-RRM; Innovative BioCeramix Inc, Vancouver, BC, Canada) or mineral trioxide aggregate (MTA) as the retrograde filling material and analyzed the relationship between some potential prognostic factors and the outcome of the surgery.

PRESS and Piezo Microsurgery (Bony Lid): A 7-Year Evolution in a Residency Program Part 1: Surgeon-defined Site Location

IntroductionTreatment of a failing endodontic procedure via microsurgical revision presents better outcomes due, in part, to the integration of the surgical operating microscope (SOM) and cone-beam computed tomography (CBCT) into clinical practice. But challenges still remain with respect to the operational locations and the techniques required to address them. Posterior sites, with substantial cortical plate thicknesses and sensitive anatomy, present the dichotomy of visualization versus postsurgical regeneration of bone. The bony lid technique bridges the gap between these 2 concepts, and the application of piezosurgery renders a precise and biocompatible osseous incision. The purpose of this paper was to outline, through case reports, the progression of piezo-guided surgery in a postgraduate resident setting.MethodsThe primary evolution of the bony lid technique relied on the transfer of measurements from defined landmarks in the CBCT volume to the cortical plate of the surgical site. The secondary evolution used the same measurement protocols transferred to a laboratory model of the patients' arch. A vacuformed stent was fabricated with pertinent fiducial markers in gutta percha defining the surgical site parameters, and a scan exposed with the stent in place. These 2 evolutions are designated as the surgeon-defined site location method and are explained in greater detail in this the first of 2 parts of the topic. All surgeries were executed using the piezosurgical method with increasing levels of guidance and precision throughout the evolution process.ResultsEach step in the technique implementation enabled the resident to assimilate a new technique and skill set while maintaining bone architecture and minimizing volume loss postoperatively. The patient benefits were an increase in intraoperative safety and postoperative comfort. The resident benefits were accelerated regeneration timetables, and increase in the confidence level of the resident and number of scheduled posterior surgical procedures.ConclusionsThe progression from crude on-site measurements to elegant and precise surgical guides enabled the access and manipulations of difficult surgical sites without compromising visibility, postoperative osseous regeneration, or patient comfort.     

The Impact of Different Diagnostic Imaging Modalities on the Evaluation of Root Canal Anatomy and Endodontic Residents' Stress Levels: A Clinical Study

Introduction

The purpose of this study was firstly to compare the impact of radiographs, cone-beam computed tomographic (CBCT) imaging, and 3D Endo software (Dentsply Sirona, Ballaigues, Switzerland) on the assessment of root canal anatomy and radiographic quality of endodontic treatment and secondly to assess stress levels in the same cohort of residents performing endodontic treatment.

Effect of Single and Contiguous Teeth Extractions on Alveolar Bone Remodeling: A Study in Dogs

Background: Tooth extraction is associated with dimensional changes in the alveolar ridge. The aim was to examine the effect of single versus contiguous teeth extractions on the alveolar ridge remodeling. Material and Methods: Five female beagle dogs were randomly divided into three groups on the basis of location (anterior or posterior) and number of teeth extracted – exctraction socket classification: group 1 (one dog): single‐tooth extraction; group 2 (two dogs): extraction of two teeth; and group 3 (two dogs): extraction of three teeth in four anterior sites and four posterior sites in both jaws. The dogs were sacrificed after 4 months. Sagittal sectioning of each extraction site was performed and evaluated using microcomputed tomography. Results: Buccolingual or palatal bone loss was observed 4 months after extraction in all three groups. The mean of the alveolar ridge width loss in group 1 (single‐tooth extraction) was significantly less than those in groups 2 and 3 (p < .001) (multiple teeth extraction). Three‐teeth extraction (group 3) had significantly more alveolar bone loss than two‐teeth extraction (group 2) (p < .001). The three‐teeth extraction group in the upper and lower showed more obvious resorption on the palatal/lingual side especially in the lower group posterior locations. Conclusion: Contiguous teeth extraction caused significantly more alveolar ridge bone loss as compared with when a single tooth is extracted.