Outcome of Root Canal Treatment in Dogs Determined by Periapical Radiography and Cone-Beam Computed Tomography Scans

The trend of radiographic healing after root canal treatment in teeth with apical periodontitis based on cone-beam computed tomography: A 4-year longitudinal study

OBJECTIVES

The aim of this study was to observe the radiographic healing of periapical lesions after root canal treatment via volumetric measurements based on cone-beam computed tomography (CBCT) over 4 years.

METHODS

In total, 162 single-root teeth from patients with chronic periapical periodontitis who underwent primary root canal treatment were included in this retrospective study. Follow-up visits were scheduled at 1, 2, and 4 years after treatment. The volume of radiolucency at pretreatment and follow-up were measured, and the radiographic outcomes were classified into 4 categories: absence, reduction, uncertain or enlargement. Reduction or enlargement was considered when the volumetric change in radiolucency was 20 % or more.

RESULTS

During the 4-year follow-up period, 128 teeth were reviewed at least once, including 3 extracted teeth. Of the remaining 125 teeth, the volume of radiolucency was reduced in 116 teeth (90.6 %), uncertain in 5, and enlarged in 4 teeth during 1 to 4 years after treatment. Among the 43 teeth with reduced radiolucency at 1 year after treatment, 42 (97.7 %) had continuing reduced lesions at 4 years. In the 2 teeth with enlarged radiolucency at 1 year, the volume of radiolucency doubled at 4 years. Cox regression analysis revealed that the preoperative radiolucency size was a risk factor for persistent periapical radiolucency.

CONCLUSIONS

The efficacy of root canal treatment for apical periodontitis was predictable. When the radiolucency changed by 20 % or more in volume on CBCT scans at 1 year after treatment, reversal of the radiographic healing tendency was rare.

CLINICAL SIGNIFICANCE

The volumetric changes in radiolucency on CBCT could reflect trends in the healing process and may foster early clinical decision-making.

Outcomes of root canal treatments with three different sealers for 120 fractured maxillary fourth premolar teeth in small-to medium-sized dogs

Introduction

Tooth fracture is one of the most common traumatic maxillofacial injuries in dogs and cats. For fractures with pulp exposure occurring in functionally important teeth, the literature indicates that root canal treatment (RCT) is an effective therapy option that may be the remedy of choice before extraction. The most commonly reported fractures in the United States involve canine teeth; however, fractures of the maxillary fourth premolars are more common in Korea, where there are many small-and medium-sized dogs. RCT mechanically and chemically removes pulp tissue and bacteria (cleaning and shaping) from the infected root canal, and obturates the root canal with filling material to restore tooth functionality without inflammation. Various techniques, instruments, and materials used in humans have been modified for application in veterinary dentistry.

Methods

This study analyzed the results of RCT of the maxillary fourth premolar in 120 small-and medium-sized dogs (weighing less than 25 kg) using three different sealers (silicone-based sealer, bioceramic sealer, and calcium hydroxide-based sealer) through a simple application of the single-cone technique.

Results

The overall success rate of RCT in maxillary fourth premolars was 90.83%, with 8.33% no evidence of failure (NEF) and 0.83% failure.

Discussion

There were no significant differences between the three different sealers. Furthermore, preexisting periapical lesion (PAL) was reconfirmed as a factor in reducing the success rate of RCT. In addition, the working length and master apical file of each root were analyzed in our study as a novel reference for endodontic veterinarians.

Radiographic Outcome of Vital Teeth Treated with Prosthodontic Crowns in Dogs: 26 Cases (2015-2017)

This retrospective study evaluated the effects of prosthodontic crown placement on tooth vitality. Prosthodontic crown placement may be indicated for vital teeth affected by attrition, abrasion, uncomplicated crown fractures, enamel defects, and enamel hypoplasia. This study evaluated 26 vital teeth in 17 patients at the time of crown placement and after 1-year following crown placement. Dental radiographs were used to determine vitality of the 26 teeth. Twenty-five teeth were found to be vital and 1 tooth was non-vital 1-year after crown placement. These results demonstrated that tooth vitality was maintained after titanium alloy crown placement to treat crown attrition, abrasion, uncomplicated crown fractures, and enamel defects.

CBCT in contemporary endodontics

Cone-beam computed tomography (CBCT) is a three-dimensional imaging modality which can aid endodontic diagnosis and treatment planning. While there are guidelines available describing the indications, there are divergent philosophies on when this technology should be applied in clinical practice. This paper reviews the applications of CBCT including the clinical relevance of parameters which can be assessed, highlights the limitations of this technology, and provides guidance on how to maximise its clinical utility.

Volumetric Assessment of Apical Periodontitis Using Cone-Beam Computed Tomography-A Systematic Review

This systematic review aimed to investigate the scientific literature on volumetric studies concerning the diagnosis and treatment of apical periodontitis using CBCT. A systematic review protocol was written following the preferred reporting items for the systematic reviews and meta-analyses (PRISMA) checklist. Four electronic databases were searched for relevant publications in English, which were published up to 21 January 2023. The inclusion criteria and corresponding search keys were applied. The risk of bias was assessed using the Joanna Briggs Institute Meta-Analysis of Statistic Assessment and Review Instrument. The search strategy identified 202 studies, with 123 studies excluded during the title and abstract screening and 47 studies left for full text screening. A total of 17 studies met the inclusion criteria. The lesion volume was measured and classified according to different indices which compared the effectiveness of their diagnostics. Moreover, the volume of AP lesions increased with the thickness of the maxillary sinus mucosa in primary and secondary infections and decreased due to endodontic treatment. Volumetric measurements using CBCT are useful in the correct definition of periapical tissue pathosis using a CBCT periapical volume index and assessment of the dynamics of the treatment of apical lesions.

The Changes in Size of Periapical Lesions after Root Canal Treatments Assessed by Digital Periapical Radiography and Cone-Beam Computed Tomography: A 2-Years Prospective Clinical Study

Background and Objectives: There is limited information regarding comparison of long-term dynamics of periapical bone destruction estimated by digital periapical radiography (DPR) and by cone-beam computed tomography (CBCT). This study aimed to compare the radiographically assessed periapical changes of endodontically treated teeth over 2 years of follow-up and to analyse disagreements in periapical lesion size estimates around the same roots using DPR and CBCT. Materials and Methods: A total of 176 endodontically treated teeth, of 128 patients with apical periodontitis, were assessed by DPR and CBCT, at baseline and after 2 years. All periapical radiolucencies were categorised by severity (S0, S1, S2, S3) concerning their size. Descriptive statistics were used to report distribution of the radiolucencies at baseline and at follow-up, and their size transitions over 2 years. Site-specific comparison of the radiolucencies identified by two methods was performed using Z test and Pearson’s chi-square test. Results: majority of the detected radiolucencies were scored as S0: 65% and 68% at baseline; 89% and 83% at follow-up, by DPR and CBCT, respectively. Site-specific score comparison showed that disagreements comprised 18% and 20% of the total number of radiolucencies detected by DPR and CBCT, respectively. There were more disagreements between DPR and CBCT within categories S1 and S2 + S3 compared to S0: at baseline, they comprised 17–33% and after two years 62–95% of all detected radiolucencies within the category. 65% of non-matching score transitions over two years occurred between S0 and S1. The CBCT-based evaluation resulted in negative treatment outcomes for 10 more root canals than the DPR-based result. Conclusions: Most remarkable disagreement between DPR and CBCT recordings was observed within the radiolucency categories S2 and S3. However, the diagnostic accuracy of both radiographic methods was questionable as it resulted in a high proportion of non-matching S0-S1 lesion transitions over 2 years.

Radiographic Outcome of the Endodontic Treatment of 55 Fractured Canine Teeth in 43 Dogs (2013-2018)

Medical records from 4 private practice veterinary dentistry specialty clinics were reviewed for a 5-year period (2013-2018) to identify dogs that had a fractured canine tooth treated by root canal therapy and returned for subsequent follow-up evaluation. Evaluation criteria included the presence of complete medical records with diagnostic quality intraoral radiographs for each procedure visit with a minimum of 6 months between visits. Forty-three dogs with a total of 55 endodontically treated canine teeth were identified and evaluated. Root canal treatment outcome was defined as successful, no evidence of failure (NEF), or failure based on radiographic findings. Patient age, time from initial treatment to follow-up, obturation material used, radiographic quality of obturation (including voids, overfill, and retention of fractured endodontic files), radiographic evidence of periapical disease and/or presence of external inflammatory root resorption (EIRR), and the presence or absence of a full coverage metal crown were evaluated. Treatment was classified as successful in 51 (92.73%) teeth, NEF in 3 (5.45%) teeth, and failure in 1 (1.82%) tooth. The results suggest that endodontic treatment of fractured canine teeth in dogs is a successful treatment option that allows for retention of this functionally important tooth.

A critical analysis of research methods and experimental models to study irrigants and irrigation systems

Irrigation plays an essential role in root canal treatment. The purpose of this narrative review was to critically appraise the experimental methods and models used to study irrigants and irrigation systems and to provide directions for future research. Studies on the antimicrobial effect of irrigants should use mature multispecies biofilms grown on dentine or inside root canals and should combine at least two complementary evaluation methods. Dissolution of pulp tissue remnants should be examined in the presence of dentine and, preferably, inside human root canals. Micro-omputed tomography is currently the method of choice for the assessment of accumulated dentine debris and their removal. A combination of experiments in transparent root canals and numerical modeling is needed to address irrigant penetration. Finally, models to evaluate irrigant extrusion through the apical foramen should simulate the periapical tissues and provide quantitative data on the amount of extruded irrigant. Mimicking the in vivo conditions as close as possible and standardization of the specimens and experimental protocols are universal requirements irrespective of the surrogate endpoint studied. Obsolete and unrealistic models must be abandoned in favour of more appropriate and valid ones that have more direct application and translation to clinical Endodontics.

A Critical Review of the Differential Diagnosis of Root Fracture Line in CBCT scans

The objective of this critical review of literature is to discuss relevant clinical factors associated with root fractures (RF) visualized by using a new CBCT software. RF constitutes a common occurrence and a challenge in clinical practice, in which the diagnosis becomes essential for the definition of rapid and precise decision-making. The characterization of RF may involve different aspects, such as orientation of the fracture line (horizontal, vertical, oblique), root position of the fracture (cervical, middle, apical third), fracture's coronal-radicular position (coronary, coronal-radicular, radicular), continuity of the fracture (crack, incomplete fracture, complete), bone extension of the fracture (supraosseous, bone level, infraosseous fracture). Imaging examinations have been routinely used to aid in the RF diagnosis. Even with high-resolution cone-beam computed tomography (CBCT) scans, many doubts often remain about the diagnostic outcome. Many interferences in the analysis of image quality to determine the diagnosis are identified, such as the sharpness, the noise, light and dark artifacts, among others. The professional's knowledge is essential for identifying the different patterns of fracture lines and their repercussions on adjacent bone tissues, as well as for the analysis of artifacts that may hide or show similarities to fracture lines. Fractures lines and root fractures that may be associated with phantom conditions that mimic fractures should be carefully analyzed. CBCT is the exam indicated to identify a root fracture. It is also added to the success of the diagnosis that the professional has scientific knowledge, training and mastery of advanced CBCT software.

Cell therapy: A potential solution for the healing of bone cavities

Aim

To Explore whether the use of autologous BMMNCs as a cell therapy technique will improve the healing of bone cavities in vivo.

Methodology

After achieving proper anesthesia, mononuclear cells were isolated from iliac crest's bone marrow aspirates (BMMNCs). Then access cavity, root canal preparation, and filling were done in third and fourth premolars, followed by amalgam coronal restoration. After that, a flap was reflected and a standardized bone cavity was drilled, the related root-ends were resected and retrocavity was drilled and filled with MTA. Before repositioning the flap, the bone cavity was filled with the desired filling material according to its corresponding group (n = 8): CollaCote group; where collagen scaffold was used, MNC group; in which CollaCote® loaded with isolated BMMNCs were applied, Biogen group; in which BIO-GEN® graft material was applied and finally Control group; where the bone cavities were left empty to heal spontaneously. Evaluations of healing of the bone cavities were done radiographically and histologically.

Results

The MNC group induced the best healing potential with statistical significant difference from other groups.

Conclusion

cell therapy utilizing autologous BMMNCs looks to beat the conventional therapies and convey a significant improvement in the healing of the bone cavity in vivo.

Comparison of Cone-beam Computed Tomography and Periapical Radiography to Determine the Proximity of Periapical Lesions to Anatomical Structures in Premaxillary Area prior to Surgical Endodontics: A Clinical Study

Aim

In the anterior maxillary region when periapical (PA) surgery is contemplated, knowledge of relation between root apices and lesion, spatial relationship of tooth root to adjacent anatomical structures is essential. The aim of this study was to compare cone-beam computed tomography (CBCT) and PA radiography to determine the proximity of PA lesions to anatomical structures in the premaxillary area for decision-making before apical surgery.

Materials and methods

Twenty subjects were selected. Three endodontists viewed PA radiographs and CBCT images. These observers (1) determined proximity of lesion to anatomical structures and (2) made decisions on treatment based on each imaging modality. Chi-square test was used to check the relationship between the treatment plans given by PA radiographs and CBCT images. Reliability of the observations was evaluated using intraclass correlation (ICC).

Results

Significant difference was noted in the treatment plan selected by the observers using the two modalities (p < 0.05).

Conclusion

After the lesions were observed with CBCT, there was an increase in the number of teeth involved with the lesion. A change in the observer's treatment plan was recorded after viewing the CBCT scans.

How to cite this article

Sheth K, Kapoor S, Daveshwar S, et al. Comparison of Cone-beam Computed Tomography and Periapical Radiography to Determine the Proximity of Periapical Lesions to Anatomical Structures in Premaxillary Area prior to Surgical Endodontics: A Clinical Study. Int J Clin Pediatr Dent 2020;13(4):322-326.

Applications of cone beam computed tomography in endodontics

Background

Endodontic disease can adversely affect the quality of life and therefore early diagnosis and consequent timely treatment is of paramount importance for the Endodontist. Radiology is an essential component in treatment planning, disease monitoring and assessment of treatment outcome. Periapical radiographs and panoramic radiography are frequently utilised but they provide only two-dimensional representation of three-dimensional structures. The advent of cone beam computed tomography (CBCT) offers three-dimensional accuracy of the hard tissue images with a reasonable cost and this has revolutionised imaging of the dentomaxillofacial structures. This imaging system has been seen to overcome some limitations of conventional radiography, as brought out in this review. The improvement in the accuracy is, however, accompanied at the cost of increased radiation exposure to the patient. Nevertheless, smaller areas of exposure are normally appropriate for endodontic imaging, and adjustment in the exposure parameters can further moderate the effective dose (Loubele et al. 37(6):309-18, 2008).

Aims and objectives

The aim of this review is to present the pertinent literature on the various applications of cone beam computed tomography in the field of endodontics.

Methods

Literature was electronically searched on the following sources; Medline and Keats Library. Further, a manual search was performed on the following journals: International Endodontic Journal, Journal of Endodontics, Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, Endodontology, Journal of Dental Research, European Journal of Oral Sciences & Odontology and Dentomaxillofacial Radiology. A preliminary search was performed to gain an idea of the available literature using keywords ‘Cone Beam Computed Tomography’ to view the volume of the literature evident and identify questions to be addressed in this review. The initial search showed 243 potential articles. After scrutinising the titles and abstracts of the retrieved articles, 70 relevant studies were reviewed in full text. Furthermore, ‘published guidelines on the use of CBCT’ were also searched so as to include the results as an additional source material. All the articles eligible to be included in the review were in the English language and ranged from the year 1960 to the present. Also all the studies reviewed were based on the various uses of cone beam computed tomography in the field of endodontics. The keywords used to search were ‘Cone Beam Computed Tomography (CBCT)’, ‘Conventional radiography’, ‘Applications of CBCT in endodontics’, ‘CBCT and tooth morphology’, ‘CBCT and apical periodontitis’, ‘CBCT and vertical root fractures’, ‘CBCT and resorption’, ‘CBCT and pre-surgical assessment’, ‘CBCT and dento-alveolar trauma’ and ‘CBCT and endodontic outcome’.

Results

Every case is unique and CBCT should be considered only after studying each case individually. CBCT imaging needs to be adopted or used where information from conventional imaging systems is either inadequate for the management of endodontic problems or inconclusive. Having said that, it is safe to state that CBCT imaging has the potential to become the first choice for endodontic treatment planning and outcome assessment, especially when new scanners with lower radiation doses and enhanced resolution would be available.

Successful Use of MTA Fillapex as a Sealant for Feline Root Canal Therapy of 50 Canines in 37 Cats

Intentional or unintentional pulp exposure of cat canines can lead to periapical disease, osteomyelitis, and oral pain. Root canal therapy (RCT) allows the retention of cat canines with pulp exposure by removing the infected pulp and replacing it with an inert material. This study used MTA Fillapex™ as a root canal sealant with gutta percha single cone obturation in 37 cats (50 canine teeth). Roots were classified as "successful," "no evidence of failure (NEF)," or "failed" at 6-month radiographic reviews. Therapy was considered "successful" if a preoperative periapical lucency had healed or not formed after treatment and any preoperative external inflammatory root resorption (EIRR) had stabilized without progression. Therapy was categorized as "NEF" if a periapical lucency had remained the same or decreased in size but not completely resolved and any preoperative EIRR had stabilized without progression. "Failed" if a periapical lucency had occurred or increased in size posttreatment or if EIRR had developed or progressed posttreatment. Thirty-two canine teeth (64%) were classified as "successful," 14 canine teeth (28%) were classified as "NEF," and 4 canine teeth (8%) were classified as "failed". The study concluded that RCT using MTA Fillapex as a root canal sealant is a suitable endodontic treatment for fractured cat canines, especially those that are periodontally or endodontically challenged.

A Comparison of 2- and 3-dimensional Healing Assessment after Endodontic Surgery Using Cone-beam Computed Tomographic Volumes or Periapical Radiographs

INTRODUCTION

The aim of this study was to compare the assessment of healing after endodontic microsurgery using 2-dimensional (2D) periapical films versus 3-dimensional (3D) cone-beam computed tomographic (CBCT) imaging.

METHODS

The healing of 51 teeth from 44 patients was evaluated using Molven's criteria (2D) and modified PENN 3D criteria. The absolute area (2D) and volume (3D) changes of apical lesions preoperatively and at follow-up were calculated by segmentation using OsiriX software (Pixmeo, Bernex, Switzerland) and ITK-Snap (free software).

RESULTS

There was a significant difference between the mean preoperative lesion volumes of 95.34 mm³ (n = 51, standard deviation [SD] ±196.28 mm³) versus 6.48 mm³ (n = 51, SD ±17.70 mm³) at follow-up (P < .05). The mean volume reduction was 83.7%. Preoperatively, mean lesion areas on periapical films were 13.55 mm² (n = 51, SD ±18.80 mm²) and 1.83 mm² (n = 51, SD ±.68 mm²) at follow-up (P < .05). According to Molven's criteria, 40 teeth were classified as complete healing, 7 as incomplete healing, and 4 as uncertain healing. Based on the modified PENN 3D criteria, 33 teeth were classified as complete healing, 14 as limited healing, 1 as uncertain healing, and 3 as unsatisfactory healing. The variation in the distribution of the 2D and 3D healing classifications was significantly different (P < .05). Periapical healing statuses incomplete healing or uncertain healing according to Molven's criteria could be clearly classified using 3D criteria.

CONCLUSIONS

CBCT analysis allowed a more precise evaluation of periapical lesions and healing of endodontic microsurgery than periapical films. Significant differences existed between the 2 methods. Over the observation period, the mean periapical lesion sizes significantly decreased in volume. Given the correct indications, the use of CBCT imaging may be a valuable tool for the evaluation of healing of endodontic surgery.

Collaborative Management of Combined Periodontal-endodontic Lesions with a Palatogingival Groove: A Case Series

INTRODUCTION

This article reports 3 representative cases of interdisciplinary management of a palatogingival groove in maxillary lateral incisors. The development, pathology, and effectiveness of management approaches in cases involving a combined periodontal-endodontic lesion with a palatogingival groove are discussed.

METHODS

We describe 3 patients with a noncontributory medical history presenting with a chief complaint related to a maxillary incisor and diagnosed with a combined periodontal-endodontic lesion with a palatogingival groove at Seoul National University Dental Hospital, Seoul, Korea.

RESULTS

Palatogingival grooves were mostly associated with deep periodontal pockets connected to a periapical lesion. Optional collaborative treatments were performed according to the condition as follows: case 1, root canal treatment (RCT), open flap debridement, odontoplasty, and guided tissue regeneration; case 2, RCT, apicoectomy, open flap debridement, and odontoplasty; and case 3, RCT, crown restoration, root planning, and odontoplasty. After clinical examination and radiographic assessments, the periapical lesion and periodontal deep pocket were successfully resolved with periodontal-endodontic collaborative treatment involving both periodontal surgical procedures (cases 1 and 2) and a nonsurgical procedure (case 3).

CONCLUSIONS

Within the limitations of this study, these case reports show that accurate diagnosis of developmental anomalies and elimination of inflammatory irritants are key factors for favorable long-term outcomes.

The Effect of File Size and Type and Irrigation Solutions on the Accuracy of Electronic Apex Locators: An In Vitro Study on Canine Teeth

Measurements of the root canal during endodontic treatment have a significant influence on the course of the therapeutic process as well as on its final result in both human and veterinary medicine. The apical constriction should be the termination point for the preparation and filling of the root canal. This research was conducted with the use of a Septodont kit consisting of a small chamber filled with the examined solution in which a healthy second incisor was placed. The step back method was applied for the root canal preparation and master apical file of 30 was used. The working length was 22 mm. The examination was conducted with the use of steel as well as nickel titanium hand instruments. Different irrigation solutions and two types of apex locators were used. Measurements of the working length of the root canal showed dependence on the size of the instrument. Examinations carried out in various environments showed that analogical measurements were obtained only for sodium hypochlorite solutions. In other environments the measured sections were shortened. Comparative examinations with the use of steel instruments demonstrated insignificant measurement differences. Compared to these results, the measurements in nickel titanium group were characterized by more considerable deviations.

Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography

The objective of this blinded study was to validate the use of cone beam computed tomography (C) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methylmethacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxillary segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT.

Combined Endodontic-Periodontal Treatment of a Palatogingival Groove

A palatogingival groove is a developmental anomaly that predisposes the involved tooth to develop a severe periodontal lesion. These grooves often present a clinical challenge because diagnosis and treatment planning require an interdisciplinary approach. This case report describes the successful management of a right maxillary lateral incisor with a deep palatogingival groove in combination with an extensive periodontal pocket and pulp necrosis of the involved tooth. Collaborative management used a combination of endodontic treatment, periodontal therapy, odontoplasty, and a periodontal regenerative procedure using protein complex derived from enamel matrix (Emdogain; Straumann, Basel, Switzerland). Despite a predicted poor prognosis, the tooth lesion healed. This report also discusses the rationale behind the treatment modalities.

Correlation between Volume of Apical Periodontitis Determined by Cone-beam Computed Tomography Analysis and Endotoxin Levels Found in Primary Root Canal Infection

INTRODUCTION

This clinical study was conducted to correlate the levels of endotoxins and bacterial counts found in primary endodontic infection with the volume of periapical bone destruction determined by cone-beam computed tomography (CBCT) analysis. Moreover, the levels of bacteria and endotoxins were correlated with the development of clinical features.

METHODS

Twenty-four root canals with primary endodontic disease and apical periodontitis were selected. Clinical features such as pain on palpation, pain on percussion, and previous episode of pain were recorded. The volume (cubic millimeters) of periapical bone destruction was determined by CBCT analysis. Endotoxins and bacterial samplings were collected by using sterile/apyrogenic paper points. Endotoxins were quantified by using limulus amebocyte lysate assay (KQCL test), and bacterial count (colony-forming units [CFU]/mL) was determined by using anaerobic culture techniques. Data were analyzed by Pearson correlation and multiple logistic regression (P < .05).

RESULTS

Endotoxins and bacteria were detected in 100% of the root canal samples (24 of 24), with median values of 10.92 endotoxin units (EU)/mL (1.75-128 EU/mL) and 7.5 × 10(5) CFU/mL (3.20 × 10(5)-8.16 × 10(6) CFU/mL), respectively. The median volume of bone destruction determined by CBCT analysis was 100 mm(3) (10-450 mm(3)). The multiple regression analysis revealed a positive correlation between higher levels of endotoxins present in root canal infection and larger volume of bone destruction (P < .05). Moreover, higher levels of endotoxins were also correlated with the presence of previous pain (P < .05).

CONCLUSIONS

Our findings revealed that the levels of endotoxins found in root canal infection are related to the volume of periapical bone destruction determined by CBCT analysis. Moreover, the levels of endotoxin are related to the presence of previous pain.

Accuracy of cone-beam computed tomography and periapical radiography in apical periodontitis diagnosis

INTRODUCTION

This study aimed to investigate the correlation and the agreement between periapical radiography (PR) and cone-beam computed tomography (CBCT) correlating to histologic findings in the diagnosis of apical periodontitis (AP).

METHODS

One hundred thirty-four premolar root canals from 10 dogs were treated after AP induction. Four months later, the animals were killed, and standard digital PRs were obtained. The area of AP was measured by using ImageJ software. CBCT (i-CAT) images from each arch were obtained, and AP area and volume were measured by using Osiri-X software. The apical inflammatory infiltrate was evaluated under light microscopy. The correlation between imaging methods was evaluated by using the Pearson coefficient. The Bland-Altman method was used to assess the agreement between PR and CBCT data. The Spearman coefficient was used to correlate the imaging data and histologic findings.

RESULTS

Despite a strong correlation between PR and CBCT areas, the agreement limits were very broad (95% limits of agreement, 0.19-1.08). PR only measured, on average, 63% of CBCT values. Although there was a strong correlation between PR area and CBCT volume, the Bland-Altman method suggests that the larger the CBCT volume, the more underestimated the PR value. When APs had a volume smaller than 6 mm(3), the PR estimation of CBCT data was unpredictable. A positive correlation was found for PR area, CBCT area, CBCT volume, and histology data.

CONCLUSIONS

The diagnosis of AP based on PR data is clinically limited, and it should not be used for scientific investigations.

A three-dimensional study of variations in root canal morphology using cone-beam computed tomography of mandibular premolars in a South Indian population

BACKGROUND

Conventional radiographic techniques being two dimensional, has its restrictions and is confined to limited diagnostic value. However, the incorporation of Cone Beam Computed Tomography (CBCT) gives a three dimensional insight to the tooth morphology and leads to better evaluation and treatment management.

AIM

The aim of this study was to evaluate and assess the root canal morphology of mandibular pre-molars in South Indian Population using CBCT radiographic technique.

MATERIALS AND METHODS

One thousand and eighty six and 814 fully erupted mandibular first and second premolars respectively were scanned using CBCT to evaluate the canal morphology according to Vertucci and Gulabiwala's classification.

RESULTS

The most common configuration in mandibular first and second premolars was Vertucci's Type I(83.81% and 93.48% respectively) followed by Type V (11.97% and 3.5% respectively).

CONCLUSION

South Indian population presented Type IV ertucci's canal morphology as the most common in mandibular first and second pre-molars followed by Type V. CBCT scanning poses a greater advantage in assessing the complexity of root canal morphology and planning an appropriate endodontic treatment for the same.

Assessment of apical periodontitis in dogs and humans: a review

Veterinary dentists commonly encounter apical periodontitis in dogs. An overview of the disease is presented, concentrating on pathogenesis and mechanisms of healing. Assessment modalities are reviewed and interpretations of treatment success and failure are discussed. The limitations of readily available diagnostic equipment are illustrated. The benefits of identifying the causative agent and resultant pathosis should not be overlooked. Well-designed clinical studies evaluating various methods of long-term follow-up for apical periodontitis in dogs are needed.

A comparative investigation of cone-beam computed tomography and periapical radiography in the diagnosis of a healthy periapex

INTRODUCTION

This research aimed to compare the appearance of healthy periapical tissues on cone-beam computed tomography (CBCT) with periapical radiography and to measure the periodontal ligament (PDL) space on CBCT for teeth with healthy and necrotic pulps.

METHODS

Patient records from specialist endodontic practices were examined for teeth that had a high-resolution (0.08-mm voxel) and small field-of-view CBCT scan, a periapical radiograph, and clinical pulp tests (CO2 and electric pulp testing). The periapical regions of the CBCT scans and radiographs were scored individually by 2 calibrated, blinded examiners by using a modified CBCT-periapical index (CBCT-PAI) for both and represented as CBCT-PAI and PAI, respectively. The Fisher exact and χ(2) statistics tested the relationships between CBCT-PAI, PAI, and pulp status.

RESULTS

Of 200 teeth included in the study, 166 showed clinical signs of pulpal health, and the CBCT-PAI score was greater than the PAI in 72% (119 of 166), with a vital pulp likely to have a radiographic PDL space widening of 0-1 mm (P < .001). Although 2 healthy teeth showed radiolucencies 2-4 mm on CBCT scan when the periapical radiograph showed none, a PDL space of greater than 1-2 mm was indicative of a necrotic pulp (P < .001).

CONCLUSIONS

Teeth with necrotic pulps were more likely to have PDL widening, but the PDL space of a healthy tooth demonstrated significant variation when examined by CBCT. The radiographic interpretation of health and disease on CBCT must be further investigated before usage in outcome or epidemiologic investigations. This research questions the traditional radiographic interpretation of the PDL space.

Comprehensive management of a complex traumatic dental injury

A 24-year-old female patient presented with complaint of palatal swelling and a sinus tract facial to tooth #22. She reported an injury to the tooth 15 years earlier and no recollection of treatment, although there was evidence of an endodontic access into the crown. Radiographically the root appeared to have stopped developing, and it was associated with a large periapical lesion. After 3 unsuccessful attempts at apexification using calcium hydroxide (CH), further examination including use of cone-beam computed tomography (CBCT) was carried out. The latter allowed for better evaluating the situation and for better planning a more comprehensive treatment plan to include surgical removal of the apical lesion. The large radiolucent area extended from tooth #21 to #23. Using a dedicated software tool developed to be used in conjunction with CBCT, volumetric assessment of the lesion was carried out for healing follow up. The root end was filled from the apical direction with newly developed accelerated silicate cement 4-5 mm into the apical part of the canal. Subsequently, the rest of the canal was filled with the same type of cement. At the 1-year postsurgical follow up, the tooth remained asymptomatic, and using the CBCT volumetric program, bony healing could be demonstrated.

A novel method to estimate the volume of bone defects using cone-beam computed tomography: an in vitro study

INTRODUCTION

The routine use of high-resolution images derived from 3-dimensional cone-beam computed tomography (CBCT) datasets enables the linear measurement of lesions in the maxillary and mandibular bones on 3 planes of space. Measurements on different planes would make it possible to obtain real volumetric assessments. In this study, we tested, in vitro, the accuracy and reliability of new dedicated software developed for volumetric lesion assessment in clinical endodontics.

METHODS

Twenty-seven bone defects were created around the apices of 8 teeth in 1 young bovine mandible to simulate periapical lesions of different sizes and shapes. The volume of each defect was determined by taking an impression of the defect using a silicone material. The samples were scanned using an Accuitomo 170 CBCT (J. Morita Mfg Co, Kyoto, Japan), and the data were uploaded into a newly developed dedicated software tool. Two endodontists acted as independent and calibrated observers. They analyzed each bone defect for volume. The difference between the direct volumetric measurements and the measurements obtained with the CBCT images was statistically assessed using a lack-of-fit test. A correlation study was undertaken using the Pearson product-moment correlation coefficient. Intra- and interobserver agreement was also evaluated.

RESULTS

The results showed a good fit and strong correlation between both volume measurements (ρ > 0.9) with excellent inter- and intraobserver agreement.

CONCLUSIONS

Using this software, CBCT proved to be a reliable method in vitro for the estimation of endodontic lesion volumes in bovine jaws. Therefore, it may constitute a new, validated technique for the accurate evaluation and follow-up of apical periodontitis.

The detection of periapical pathosis using digital periapical radiography and cone beam computed tomography - part 2: a 1-year post-treatment follow-up

AIM

Part 2 of this clinical study aims to compare the radiographic change in periapical status of individual roots determined using digital periapical radiographs versus cone beam computed tomography (CBCT) 1year after primary root canal treatment and to determine the radiological outcome of treatment for each tooth.

METHODOLOGY

Periapical radiographs and CBCT scans of 123 teeth in 99 patients assessed 1year after completion of primary root canal treatment by a single operator were compared with their respective pre-treatment (diagnostic) periapical radiographs and CBCT scans. The presence or absence as well as the increase or decrease in size of existing periapical radiolucency was assessed by a consensus panel consisting of two calibrated examiners. The panel viewed the images under standardized conditions. Paired comparison of the outcome diagnosis of individual roots and teeth was performed using generalized McNemar's or Stuart-Maxwell test of symmetry analysis.

RESULTS

The 'healed' rate (absence of periapical radiolucency) for all roots combined was 92.7% using periapical radiographs and 73.9% for CBCT (P<0.001). This rate increased to 97.2% and 89.4%, respectively, when the 'healing' group (reduced size of periapical radiolucency) was included (P<0.001). A statistically significant difference in outcome diagnosis of single roots was observed between DPA and CBCT in single-rooted teeth and the buccal or mesio-buccal roots of multi-rooted teeth (P<0.05). Analysis by tooth revealed that the 'healed' rate (absence of periapical radiolucency) was 87% using periapical radiographs and 62.5% using CBCT (P<0.001). This increased to 95.1% and 84.7%, respectively, when the 'healing' group (reduced size of periapical radiolucency) was included (P<0.002). Outcome diagnosis of teeth showed a statistically significant difference between systems (P<0.001). Reconstructed CBCT images revealed more failures (17.6%) in teeth with no pre-operative periapical radiolucencies compared with periapical radiographs (1.3%) (P=0.031). In teeth with existing pre-operative periapical radiolucencies, reconstructed CBCT images also showed more failures (13.9%) compared with periapical radiographs (10.4%).

CONCLUSION

Diagnosis using CBCT revealed a lower healed and healing rate for primary root canal treatment than periapical radiographs, particularly in roots of molars. There was a 14 times increase in failure rate when teeth with no pre-operative periapical radiolucencies were assessed with CBCT compared with periapical radiographs at 1year.

Cone beam computed tomography in endodontics

Cone beam computed tomography (CBCT) is a contemporary, radiological imaging system designed specifically for use on the maxillo-facial skeleton. The system overcomes many of the limitations of conventional radiography by producing undistorted, three-dimensional images of the area under examination. These properties make this form of imaging particularly suitable for use in endodontics. The clinician can obtain an enhanced appreciation of the anatomy being assessed, leading to an improvement in the detection of endodontic disease and resulting in more effective treatment planning. In addition, CBCT operates with a significantly lower effective radiation dose when compared with conventional computed tomography (CT). The purpose of this paper is to review the current literature relating to the limitations and potential applications of CBCT in endodontic practice.

Managing severe curvature of radix entomolaris: three-dimensional analysis with cone beam computed tomography

AIM

To present a case of a mandibular first molar with an additional distolingual root [radix entomolaris (RE)] and to discuss the use of cone beam computed tomography (CBCT) for its identification and management during root canal treatment.

SUMMARY

A 52-year-old Caucasian woman was referred for root canal treatment of the right mandibular first molar (tooth 46). After clinical and radiographic examination, a symptomatic irreversible pulpitis was diagnosed. Three periapical radiographs with different horizontal angulations revealed the presence of an additional distolingual root. This extra root, termed RE, has an incidence of <5% in the Caucasian population. A CBCT examination was also taken, which revealed a severe root canal curvature, especially in the middle third, of this supernumerary root. CBCT provided more accurate information in terms of RE inclination and root canal curvature before commencing root canal treatment. The conventional access opening was modified into a more trapezoidal cavity, and five root canals were found. All canals were instrumented with new nickel-titanium (NiTi) files to reduce the risk of fractured instruments. After preparation, the root canals were filled using thermoplastified techniques. The 1-year follow-up periapical radiographs and CBCT images revealed a continuous periodontal space with no signs of apical periodontitis.

KEY LEARNING POINTS

• Cone beam computed tomography imaging is useful in identifying the root canal system and the surrounding structures. • An accurate detection of supernumerary roots, such as RE, can avoid complications during and after root canal treatment. • The analysis of root canal curvature is important because instrument fracture has been linked to angle and radius of curvature. • The use of new instruments can reduce the incidence of instrument fracture.

Calcium hydroxide promotes cementogenesis and induces cementoblastic differentiation of mesenchymal periodontal ligament cells in a CEMP1- and ERK-dependent manner

Periodontal tissue engineering is a complex process requiring the regeneration of bone, cementum, and periodontal ligament (PDL). Since cementum regeneration is poorly understood, we used a dog model of dental pulpal necrosis and in vitro cellular wounding and mineralization assays to determine the mechanism of action of calcium hydroxide, Ca(OH)(2), in cementogenesis. Laser capture microdissection (LCM) followed by qRT-PCR were used to assay responses of periapical tissues to Ca(OH)(2) treatment. Additionally, viability, proliferation, migration, and mineralization responses of human mesenchymal PDL cells to Ca(OH)(2) were assayed. Finally, biochemical inhibitors and siRNA were used to investigate Ca(OH)(2)-mediated signaling in PDL cell differentiation. In vivo, Ca(OH)(2)-treated teeth formed a neocementum in a STRO-1- and cementum protein-1 (CEMP1)-positive cellular environment. LCM-harvested tissues adjacent to the neocementum exhibited higher mRNA levels for CEMP1, integrin-binding sialoprotein, and Runx2 than central PDL cells. In vitro, Ca(OH)(2) and CEMP1 promoted STRO-1-positive cell proliferation, migration, and wound closure. Ca(OH)(2) stimulated expression of the cementum-specific proteins CEMP1 and PTPLA/CAP in an ERK-dependent manner. Lastly, Ca(OH)(2) stimulated mineralization by CEMP1-positive cells. Blocking CEMP1 and ERK function abolished Ca(OH)(2)-induced mineralization, confirming a role for CEMP1 and ERK in the process. Ca(OH)(2) promotes cementogenesis and recruits STRO-1-positive mesenchymal PDL cells to undergo cementoblastic differentiation and mineralization via a CEMP1- and ERK-dependent pathway.

Matrix metalloproteinase expression in teeth with apical periodontitis is differentially modulated by the modality of root canal treatment

INTRODUCTION

The objective of this study was to investigate the expression of matrix metalloproteinases (MMPs) in apical periodontitis and during the periapical healing phase after root canal treatment.

METHODS

Apical periodontitis was induced in dog teeth, and root canal treatment was performed in a single visit or by using an additional calcium hydroxide root canal dressing. One hundred eighty days after treatment the presence of inflammation was examined, and tissues were stained to detect bacteria. Bacterial status was correlated to the degree of tissue organization, and to further investigate molecules involved in this process, tissues were stained for MMP-1, MMP-2, MMP-8, and MMP-9. Data were analyzed by using one-way analysis of variance followed by Tukey test or Kruskal-Wallis followed by Dunn test.

RESULTS

Teeth with apical periodontitis that had root canal therapy performed in a single visit presented an intense inflammatory cell infiltrate. Periapical tissue was extremely disorganized, and this was correlated with the presence of bacteria. Higher MMP expression was evident, similar to teeth with untreated apical periodontitis. In contrast, teeth with apical periodontitis submitted to root canal treatment with calcium hydroxide presented a lower inflammatory cell infiltrate. This group had moderately organized connective tissue, lower prevalence of bacteria, and lower number of MMP-positive cells, similar to healthy teeth submitted to treatment.

CONCLUSIONS

Teeth treated with calcium hydroxide root canal dressing exhibited a lower percentage of bacterial contamination, a lower MMP expression, and a more organized extracellular matrix, unlike those treated in a single visit. This suggests that calcium hydroxide might be beneficial in tissue repair processes.