Nonsurgical root canal therapy of large cyst-like inflammatory periapical lesions and inflammatory apical cysts

Outcome of nonsurgical management of large cyst-like periapical lesions using a modified apical negative pressure irrigation system: a case series study

OBJECTIVE

To assess the effectiveness of a self-constructed modified apical negative pressure irrigation (ANPI) system employing commonly used clinical instruments in nonsurgical root canal therapy (NSRCT) for large cyst-like periapical lesions (LCPLs).

METHODS

From 2017 to 2022, 35 patients diagnosed with LCPLs (5-15 mm) via preoperative clinical and radiographic evaluations of endodontic origin underwent NSRCT combined with ANPI. These patients were subjected to postoperative clinical and radiographic follow-up at 3 months, 6 months, 1 year, 2 years, 3 years, and 4 years, with a CBCT scan specifically conducted at 6-month follow-up. Through the reconstruction of three-dimensional cone beam computed tomography (CBCT) data, an early prognosis was facilitated by monitoring changes in lesion volume. Various treatment predictors-including sex, type of treatment, lesion size, preoperative pain, jaw, type of teeth involved, sealer extrusion, and the number of root canals-were meticulously analyzed. The evaluation of post-treatment outcomes leveraged both clinical observations and radiographic data collected during the follow-up periods. The Kruskal‒Wallis test and one-way ANOVA were also conducted to determine the independent factors influencing treatment outcomes. A significance level of 5% was established.

RESULTS

Thirty-five teeth from 35 patients with a median age of 28 years (range 24-34) were treated; the median follow-up duration was 19 months (range 12-26). The overall success rate was 91.4%, with a median lesion reduction of 77.0% (range 54.2-96.4%) at 6 months. Patients under 30 years of age exhibited a significantly greater success rate than older patients did (100.0% vs. 80.0%, p = 0.037). Other factors, such as sex, jaw, treatment type, preoperative pain, cyst size, tooth location, sealer extrusion, and the number of roots, did not significantly impact treatment outcomes.

CONCLUSIONS

Despite limitations related to the observational case-series study design and relatively small sample size, our findings suggest that utilizing the ANPI in the NSRCT for LCPLs may hold promise. The notably higher success rate in patients younger than 30 years is worth noting.

Assessment of bone regeneration after maxillary radicular cyst enucleation with or without bone grafting materials: a retrospective cohort study

OBJECTIVE

The limitations of spontaneous bone healing underscore the necessity for exploring alternative strategies to enhance bone regeneration in maxillary radicular cyst cases. This retrospective study aimed to assess the impact of a bone substitute material (i.e., Bio-Oss) on bone volume regeneration following maxillary radicular cyst enucleation using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

Seventy-three patients with maxillary radicular cysts were divided into two groups: one undergoing guided bone regeneration (GBR) with Bio-Oss and absorbable collagen membrane (n = 35), and the other receiving cyst excision alone (n = 38). Volumetric measurements using Amira software on CBCT scans evaluated bone regeneration, with cystic lesion shrinkage rates calculated. Intergroup comparisons utilized independent sample t-tests (P < 0.05), and linear regression analysis assessed the influence of preoperative cyst volume and group on bone healing.

RESULTS

Both groups showed similar success rates in bone formation at the 12-month follow-up, with no significant differences between them (mean (SD), control: 75.16 (19.17) vs. GBR: 82 (20.22), P > 0.05). Linear regression analysis revealed a negative correlation between preoperative cyst volume and bone regeneration in both groups (P < 0.05).

CONCLUSION

Bio-Oss may not significantly enhance bone augmentation in maxillary radicular cysts. In addition, preoperative cyst volume negatively affected the shrinkage rate of cystic lesions.

CLINICAL RELEVANCE

Clinicians should consider patient-specific factors such as anatomy and lesion size when determining the need for bone substitute materials. Future research could focus on optimizing treatment protocols and alternative regenerative strategies to improve patient outcomes in maxillary cyst cases.

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.

A 3-year follow-up clinical study on the preservation for vitality of involved tooth in jaw cysts through an innovative method

Jaw cysts commonly affect the oral and maxillofacial region, involving adjacent tooth roots. The management of these teeth, particularly regarding root canal therapy and apicoectomy, lacks consensus. This study introduces a novel treatment concept and refined surgical approach to preserve pulp viability in teeth involved in jaw cysts. The objective was to investigate the effectiveness and potential benefits of this approach over a 36-month follow-up period. A conservative management approach prioritized vitality preservation, reserving root canal treatment and apicectomy for cases with post-operative discomfort. A comprehensive follow-up of 108 involved teeth from 36 jaw cyst cases treated with the modified method was conducted. Clinical observation, X-ray imaging, cone-beam computed tomography (CBCT), and pulp vitality testing assessed changes in cyst size, tooth color, pulp vitality, root structure, and surrounding alveolar bone. After 36 months, our modified surgical approach successfully preserved tooth vitality in 84 involved teeth. Adverse symptoms in 19 teeth, such as redness, swelling, fistula, and pain, resolved with postoperative root canal therapy. Follow-up was lost for five teeth in two cases. No cyst recurrences were observed, and in 34 cases, the bone cavity gradually disappeared, restoring normal bone density during long-term follow-up. Our modified surgical method effectively preserves tooth vitality in jaw cysts. This innovative approach has the potential to improve the management of teeth involved in jaw cysts.

Predictors of periapical bone healing associated with teeth having large periapical lesions following nonsurgical root canal treatment or retreatment: A cone beam computed tomography-based retrospective study

AIM

Several factors influence the condition of the periapical tissues associated with root filled teeth. The primary objective of this study was to retrospectively evaluate the extent and speed of bone healing of large periapical lesions associated with nonsurgical root canal treatment or retreatment. The secondary objective was to analyse the relationship between the time to complete healing when analysed using cone beam computed tomography (CBCT) and other possible predictors that affect healing.

METHODOLOGY

Seventy-nine patients were treated during the years 2013-2020 with large periapical lesions of endodontic origin (10-15 mm) as observed on intraoral periapical radiographs (IOPAR) were included. IOPAR and CBCT were available before treatment and during the follow-up (IOPAR every 6 months and CBCT every 12 months). The volume of periapical lesions was calculated by OsiriX Lite software. Variables such as initial volume of the lesion, age, gender, type of treatment or type of root canal filling were compared to identify the differences between healed and unhealed lesions. Pearson's Chi-square test was used for categorical variables, the t-test for age and the Wilcoxon test for initial volume of the lesion. The association between time to healing and the variables was assessed using univariate analysis and multivariate analysis. The Wilcoxon test was used to observe the association of healing time with categorical variables and the correlation index was measured with the quantitative variables.

RESULTS

Of the 79 cases analysed, 60 lesions (76%) were completely healed as verified by CBCT in a mean healing time of 19 months, of which 60% healed fully between 12 and 18 months. Increase in age of patient and larger initial volume of the lesion were associated with a significantly longer healing time (p < .001). Gender, filling material and type of treatment did not have a significant effect on the healing process (p > .05).

CONCLUSIONS

Clinicians should be aware that periapical lesions in older patients and larger areas of bone loss take longer to heal. CBCT monitoring of large periapical lesions is critical and it can help clinicians in the decision-making process.

The effect of root canal treatment and post-crown restorations on stress distribution in teeth with periapical periodontitis: a finite element analysis

AIM

To evaluate the effects of root canal treatment (RCT) and post-crown restoration on stress distribution in teeth with periapical bone defects using finite element analysis.

METHODOLOGY

Finite element models of mandibular second premolars and those with periapical bone defects (spherical defects with diameters of 5, 10, 15, and 20 mm) were created using digital model design software. The corresponding RCT and post-crown restoration models were constructed based on the different sizes of periapical bone defect models. The von Mises stress and tooth displacement distributions were comprehensively analyzed in each model.

RESULTS

Overall analysis of the models: RCT significantly increased the maximum von Mises stresses in teeth with periapical bone defects, while post-crown restoration greatly reduced the maximum von Mises stresses. RCT and post-crown restoration slightly reduced tooth displacement in the affected tooth. Internal analysis of tooth: RCT dramatically increased the maximum von Mises stress in all regions of the tooth, with the most pronounced increase in the coronal surface region. The post-crown restoration balances the internal stresses of the tooth and is most effective in periapical bone defect - 20-mm model. RCT and post-crown restoration slightly reduced the tooth displacement in all regions of the affected tooth.

CONCLUSIONS

Root canal treatment seemed not to improve the biomechanical state of teeth with periapical bone defects. In contrast, post-crown restoration might effectively balance the stress concentrations caused by periapical bone defects, particularly extensive ones.

Radiolucent lesions that may resemble inflammatory periapical lesions: A review article

Non-endodontic lesions (NEL) closely resemble lesions of endodontic origin. Its etiology can be odontogenic, non-odontogenic, neoplastic, or anatomic variations that can resemble inflammatory periapical lesions in the periapical area. Inflammatory periapical lesions are caused by pulpal pathoses and require endodontic treatment. Since numerous NEL may resemble inflammatory periapical lesions, they can lead to misdiagnosis and inappropriate management. Thus, a detailed review of the patients' medical and dental histories with clinical examination, including radiographic findings, is essential for the proper assessment of periapical lesions. Numerous cases of misdiagnoses of NEL have been reported in literature. Thus, this review aimed to strengthen the awareness of clinicians on periapical radiolucency, which may resemble inflammatory periapical lesions.

Pioneering Periapical Healing: The Novel Synergy of Mineral Trioxide Aggregate and Injectable Platelet-Rich Fibrin

This case report presents a novel non-surgical approach for managing a substantial periapical lesion associated with tooth 12 using a combination of injectable platelet-rich fibrin (i-PRF) and mineral trioxide aggregate (MTA). A 28-year-old male patient presented with pus discharge and intermittent swelling following a history of dental trauma. Clinical and radiographic assessments confirmed a large periapical cyst associated with tooth 12. The treatment involved root canal therapy with calcium hydroxide medication, leading to symptom relief. Subsequently, i-PRF combined with MTA was used as a regenerative material for periapical healing. Follow-up examinations at three, six, and nine months showed complete resolution of symptoms and radiographic evidence of lesion healing. This innovative technique demonstrates the potential of i-PRF and MTA synergy in the non-surgical management of periapical lesions, avoiding the risks associated with surgical interventions and promoting effective tissue healing.

A comparison of online and face-to-face modalities in endodontic preclinical education: A retrospective study

PURPOSE

The aim of this study was to evaluate the competency of undergraduate students in following the principles of access cavity preparation and the radiographic quality of root canal filling in maxillary molar teeth in either online or face-to-face education courses during the novel coronavirus disease 2019 (COVID-19) pandemic.

METHODS

A total of 178 extracted maxillary molar teeth that underwent endodontic dental treatment by undergraduate students who completed the endodontic preclinical practice course online or face-to-face during the COVID-19 pandemic were retrospectively analyzed. A visual access cavity examination determined the form, width of the cavity, deroofing of the pulp chamber, and the presence of a perforation. Root canal fillings were examined radiographically on periapical radiographs for length, homogeneity, taper, and the presence of iatrogenic defects. Statistical analysis was performed using the chi-square test.

RESULTS

The incidence of incorrect form, wide cavities, and perforation was statistically higher in the online group than in the face-to-face group (p < 0.05). It was determined that root filling length and homogeneity were more successful in the face-to-face group (p < 0.05). When evaluated for iatrogenic errors, the presence of broken instruments was found to be significantly higher in the online group (p < 0.05). There was no significant difference between the groups in other iatrogenic errors and the taper of the root canal filling (p > 0.05).

CONCLUSION

The students who underwent face-to-face education were more successful in accessing cavity preparation and root canal fillings than the students who undertook online education.

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

RATIONALE AND OBJECTIVES

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Association between Clinical/Radiographic Characteristics and Histopathological Diagnoses of Periapical Granuloma and Cyst

OBJECTIVE

 The aim of this study was to determine the association between clinical/radiographic characteristics and histopathological diagnoses of periapical granuloma and cyst obtained from the teeth treated with endodontic microsurgery.

MATERIALS AND METHODS

 The clinical, radiographic (periapical and cone-beam computed tomography), and histopathological data were collected from patients' dental records of endodontic microsurgery on the teeth with periapical lesions. These lesions were histopathologically diagnosed as either granuloma or cyst, at the Endodontic Clinic, Faculty of Dentistry, Mahidol University, Bangkok, Thailand, from 2016 to 2021 according to inclusion and exclusion criteria. The data were analyzed using bivariate analysis and a multinomial logistic regression at a significance level of p-value less than 0.05.

RESULTS

 A total of 83 patients (58 females and 25 males) with an average age of 45 to 49.5 years old met the criteria including 68 periapical granulomas (81.9%) and 15 periapical cysts (18.1%). A periapical lesion involving multiple teeth in a periapical radiograph was significantly associated with the histopathological diagnosis of periapical cyst (p < 0.05). Such periapical lesion was six times more likely to be periapical cyst than periapical granuloma.

CONCLUSIONS

 A significant factor for predicting periapical cyst from periapical granuloma was the presence of a periapical lesion with multiple-teeth involvement in a dental radiograph.

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.

Application of apical negative pressure irrigation in the nonsurgical treatment of radicular cysts: A case report

BACKGROUND

Radicular cysts are one of the most common odontogenic cystic lesions found in the jaw. Nonsurgical treatment of large radicular cysts is a topic of ongoing debate, and there is still no clear consensus on the most effective therapies. The apical negative pressure irrigation system aspirates the cystic fluid and releases the static pressure in the radicular cyst, representing a minimally invasive approach for decompression. In this case, the radicular cyst was in close proximity to the mandibular nerve canal. We used nonsurgical endodontic treatment with a homemade apical negative pressure irrigation system and the prognosis was good.

CASE SUMMARY

A 27-year-old male presented to our Department of General Dentistry with complaints of pain in the mandibular right molar when chewing. The patient had no history of drug allergies or systemic disease. A multidisciplinary management approach was designed and included root canal retreatment with a homemade apical negative pressure irrigation system, deep margin elevation and prosthodontic treatment. According to a 1-year follow-up period, the patient showed a favorable outcome.

CONCLUSION

This report reveals that nonsurgical treatment with an apical negative pressure irrigation system may provide new insights into the treatment of radicular cysts.

Cystic Lesions of the Jaws: The Top 10 Differential Diagnoses to Ponder

BACKGROUND

Cystic lesions of the gnathic bones present challenges in differential diagnosis. This category includes a smorgasbord of odontogenic and non-odontogenic entities that may be reactive or neoplastic in nature. While most cystic jaw lesions are benign, variability in biologic behavior makes distinction between these entities absolutely crucial.

METHODS

Review.

RESULTS

Two clinical cases are presented in parallel and are followed by an illustrated discussion of the ten most likely differential diagnoses that should be considered when confronted with a cystic jaw lesion. Strong emphasis is placed on the histologic differences between these entities, empowering readers to diagnose them with confidence. Perhaps even more importantly, the more common diagnostic pitfalls in gnathic pathology are discussed, recognizing that a definitive diagnosis cannot be rendered in every situation. The histologic diagnoses for the two clinical cases are finally revealed.

CONCLUSION

Cystic lesions of the maxilla and mandible may be odontogenic or non-odontogenic. The most common cystic lesions are the reactive periapical cyst, and the dentigerous cyst (which is developmental in nature). It is important to note that cystic neoplasms also occur in the jaws, and that the presence of inflammation may obscure the diagnostic histologic features of lesions like odontogenic keratocyst and unicystic ameloblastoma. Ancillary testing is of limited diagnostic value in most scenarios. However, both clinical and radiographic information (such as the location, size, duration, associated symptoms, and morphology of the lesion in its natural habitat) are significantly useful.

The expression of cyclic GMP-AMP synthase in human apical periodontitis: A laboratory investigation

AIM

As a key DNA sensor, cyclic GMP-AMP synthase (cGAS) has emerged as a major mediator of innate immunity and inflammation. Human apical periodontitis has yet to be studied for the presence of cGAS. This investigation was conducted to determine if cGAS is involved in the pathological process of human apical periodontitis.

METHODOLOGY

Sixty four human periapical lesions, comprising 20 periapical granulomas and 44 radicular cysts, were employed in this investigation. Healthy gingiva (n = 6), dental pulp (n = 3), and apical papilla (n = 3) were used as control samples. The expression of cGAS in the periapical tissues was discovered using immunohistochemical staining. mRNA-Sequencing and qRT-PCR were utilized to determine the differentially expressed genes (DEGs) associated with DNA-sensing signalling in periapical lesions compared to the healthy control. Immunofluorescence labelling was used to identify the co-expression of cGAS, interleukin-1β, and interleukin-18.

RESULTS

A significantly greater expression level of cGAS was discovered in the periapical lesions, with no significant difference between radicular cysts and periapical granulomas. mRNA-Sequencing analysis and qRT-PCR identified differentially expressed mRNA, such as cGAS and its downstream DEGs, between periapical lesions and healthy control tissues. Immunofluorescence labelling further revealed that cGAS, interleukin-1, and interleukin-18 were co-localized.

CONCLUSIONS

These observations imply that along with the synthesis of interleukin-1 and interleukin-18, cGAS may be involved in the aetiology of apical periodontitis.

Creating an atlas of the bone microenvironment during oral inflammatory-related bone disease using single-cell profiling

Oral inflammatory diseases such as apical periodontitis are common bacterial infectious diseases that may affect the periapical alveolar bone tissues. A protective process occurs simultaneously with the inflammatory tissue destruction, in which mesenchymal stem cells (MSCs) play a primary role. However, a systematic and precise description of the cellular and molecular composition of the microenvironment of bone affected by inflammation is lacking. In this study, we created a single-cell atlas of cell populations that compose alveolar bone in healthy and inflammatory disease states. We investigated changes in expression frequency and patterns related to apical periodontitis, as well as the interactions between MSCs and immunocytes. Our results highlight an enhanced self-supporting network and osteogenic potential within MSCs during apical periodontitis-associated inflammation. MSCs not only differentiated toward osteoblast lineage cells but also expressed higher levels of osteogenic-related markers, including Sparc and Col1a1. This was confirmed by lineage tracing in transgenic mouse models and human samples from oral inflammatory-related alveolar bone lesions. In summary, the current study provides an in-depth description of the microenvironment of MSCs and immunocytes in both healthy and disease states. We also identified key apical periodontitis-associated MSC subclusters and their biomarkers, which could further our understanding of the protective process and the underlying mechanisms of oral inflammatory-related bone disease. Taken together, these results enhance our understanding of heterogeneity and cellular interactions of alveolar bone cells under pathogenic and inflammatory conditions. We provide these data as a tool for investigators not only to better appreciate the repertoire of progenitors that are stress responsive but importantly to help design new therapeutic targets to restore bone lesions caused by apical periodontitis and other inflammatory-related bone diseases.

Outcome and associated predictors for nonsurgical management of large cyst-like periapical lesions: A CBCT-based prospective cohort study

AIM

The aim of this cone-beam computed tomography (CBCT)-based study was to evaluate the outcome of nonsurgical root canal treatment (RCT) performed for the management of large cyst-like periapical lesions (LCPL) and to identify the predictive factors affecting healing.

METHODOLOGY

Fifty-four subjects (77 permanent maxillary anterior teeth) with LCPL (>10 mm) of endodontic origin were included. A single operator performed standardized multi-visit RCT. Patients were clinically and radiographically examined at 6, 12 months, and a CBCT scan was taken at 24 months. Two independent blinded evaluators measured the pre- and postoperative volume of periapical lesions on CBCT scans using ITK snap software (version 3.8.0-beta-20181028-win64). The outcome was assessed as a percentage change in lesion volume and dichotomized as success (resolved/reduced) or failure (unchanged/enlarged). Ten preoperative (gender; age; intraoral draining sinus, soft tissue swelling, tooth discoloration, pulp canal obliteration, open apex, root resorption, cortical bone defect and lesion volume) and four intraoperative (apical extent and density of root filling; number of treatment visits and type of root filling) predictive factors were observed. Bivariate and stepwise multivariable linear regression analysis was performed to identify independent predictors affecting treatment outcomes. The significance level was set at 5%.

RESULTS

A recall rate of 88% was achieved. The success rate of RCT was 82.2% (8.9% resolved, 73.3% reduced). Median lesion volume reduction was 75% (IQR 61%-93%). No pre- or intra-operative factors were related to treatment failure. However, presence of preoperative cortical bone defect (palatal versus no cortical defect, β = -51.5; 95% CI: -86.9 to -16, p = .006) and apical extent of obturation (long versus flush, β = -27.2; 95% CI: -53.8 to -0.6, p = .04) were negatively associated with reduction in lesion volume (%).

CONCLUSION

Large cyst-like periapical lesions may be successfully managed with RCT. Preoperative cortical bone defect and apical extent of obturation may negatively influence osseous healing.

Endodontic Microbial Communities in Apical Periodontitis

INTRODUCTION

Apical periodontitis (AP) represents an inflammatory condition of peri-radicular tissues due to invasion and colonization of bacteria in the root canals. Primary apical periodontitis (PAP) is associated with untreated necrotic root canal and can be efficiently treated with endodontic treatment to remove bacteria. Persistent/secondary apical periodontitis (SAP) is a perpetual periapical lesion due to unsuccessfully treated root canals after an initial apparent healing of the tooth. The aim of the study was evaluating the microbial communities associated with root canals using Nanopore sequencing.

METHODS

Seventeen samples from the root canals of 15 patients with AP were Polymerase Chain Reaction-amplified for 16s ribosomal DNA gene and sequenced. Information regarding the presence or absence of AP symptoms, PAP and SAP, and periapical index of patients were recorded.

RESULTS

Firmicutes, Bacteroidetes, and Actinobacteria were the most abundant phyla detected and Phocaeicola, Pseudomonas, Rothia, and Prevotella were the most prominent genera. In samples of patients with AP symptoms, the most frequent detected genera were Cutibacterium, Lactobacillus, Pseudomonas, Dialister, Prevotella, and Staphylococcus. In PAP samples, the most represented genera were Cutibacterium, Lactobacillus, Pseudomonas, and Prevotella, whilst in SAP cases were Cutibacterium, Prevotella, Atopobium, Capnocytophaga, Fusobacterium, Pseudomonas, Solobacterium, and Streptococcus.

CONCLUSIONS

The results provide additional information on the microbiota of root-canals. These data evidence the complexity of the microbiota and the relationship with many clinical and endodontic conditions. Future studies must evaluate these conditions and identify their role in inducing bone damage and local and systemic disease, aiming to better elucidate the relationship between microbes and endodontic pathologies.

Frequency and Demographic Profile of Odontogenic Cysts in Riyadh, Saudi Arabia: Retrospective Multicenter Study

Odontogenic cysts (OCs) are etiologically diverse conditions with a shared origin in the jaws. Unfortunately, there is a scarcity of published data regarding OC frequency, treatment, and follow-up information in Saudi Arabia, especially from tertiary centers.

OBJECTIVES

The study aims to assess the relative frequency, clinicopathological features, treatment, and follow-up of OCs in three tertiary medical centers.

METHODS AND MATERIAL

OCs were identified from King Abdulaziz Medical City, King Fahad Medical City, and Prince Sultan Military Medical City from January 2010 to December 2021.

RESULTS

Three hundred and seventy-two cases of OCs were identified from the archive of three medical centers in Riyadh; one hundred and forty-nine (40%) cases were retrieved from Prince Sultan Military Medical City. The mean age of all OCs was 32 years (range 2-90), with 225 (60.4%) cases occurring in males. There was an almost equal distribution of OCs between the maxilla (47.0%) and the mandible (53.0%). The apical radicular cyst (ARC) accounted for half of the cases, followed by dentigerous cyst (DC) (29.3%) and odontogenic keratocyst (OKC) (14.2%). Enucleation was the most common treatment modality (52.8%), followed by excision (35.0%). Thirteen cases showed recurrence: one ARC, four DCs, and eight OKCs.

CONCLUSION

This is the first large multicenter study of OCs in Riyadh, Saudi Arabia. All three centers showed that ARC was the most common, followed by DC and OKC.

Management of periapical lesion with persistent exsudate

Resumo Este relato de caso descreve o tratamento e acompanhamento de um molar inferior em uma jovem de 18 anos com cisto periapical. Assim, torna-se importante saber quais opções devemos tomar diante de uma situação clínica que não podemos resolver pelos métodos convencionais, e quais técnicas e abordagens temos para alcançar o sucesso do tratamento. Este caso mostrou o plano de tratamento e acompanhamento, por meio de imagens de tomografia computadorizada de feixe cônico (TCFC), de um molar inferior previamente tratado com grande abscesso periapical e lesão cística, no qual, a primeira abordagem do plano de tratamento foi fazer o retratamento endodôntico. Durante o preparo químico-mecânico a presença de exsudato purulento intracanal permanente impossibilitou a secagem dos canais, impedindo a obturação do sistema de canais radiculares. Devido a essa situação clínica, foi realizada abordagem cirúrgica com a intenção de reduzir esse exsudato permanente e executar uma técnica de descompressão. Após um ano de acompanhamento, os achados clínicos e radiográficos indicaram processo de reparo.

Evaluation of ultrasonography as a diagnostic tool in the management of periapical cysts and granulomas: A clinical study

Purpose

The aim of this study was, firstly, to determine the concordance of ultrasonographic and histopathological diagnoses in patients in whom apical resection was already indicated. Secondly, this study aimed to determine whether lesions were periapical granulomas or cysts, and to compare them after root canal treatment using ultrasonography and periapical radiographs.

Materials and Methods

In the first stage of the study, ultrasonographic and histopathologic diagnoses of 10 lesions were compared. Secondly, the periapical radiographs and ultrasonographic images of 44 lesions were measured. The presence of internal vascularity was determined by ultrasonographic color and power Doppler modes. Follow-up examinations of healing after root canal treatment were performed using ultrasonography and periapical radiographs, and these modalities were compared.

Results

In the periapical granuloma and cyst groups, the measurement values decreased for all variables. There was no significant difference in the dimensional changes of lesions between the 2 groups, and ultrasonography and periapical radiographs were compatible. The pre-diagnoses were compared with histopathological diagnoses and were found to be compatible.

Conclusion

The ultrasonographic color and power Doppler techniques could be an effective method for diagnosing periapical lesions as cysts or granulomas. After root canal treatment of granulomas and cysts, the dimensional shrinkage and healing patterns appear to be similar. Ultrasonography and periapical radiographs were consistent in terms of dimensional comparisons, and ultrasonography may be an alternative method for follow-up of the healing of periapical lesions.

Epidemiological evaluation of jaw cysts according to the new WHO classification: a 30-year retrospective analysis

The aim of the present study was to analyze the epidemiology of maxillofacial odontogenic and non-odontogenic cysts diagnosed for 30 years in a Brazilian population. A retrospective descriptive cross-sectional study was performed. Biopsy records were obtained from the archives of a Brazilian referral center between 1989 and 2019. Data regarding age, gender, anatomical location, and histopathological diagnosis were collected and categorized. Further, a literature search for similar studies was performed. A total of 6.994 biopsy records were evaluated, but only 367 (5.24%) cases were classified as odontogenic cysts (OC) or non-odontogenic cysts (NOC). Among all cystic lesions, 341 cases (92.9%) were OC and 26 cases (7.1%) were NOC. These lesions were more common in females (n = 208 / 56.67%) and located mostly in the mandible (n = 195 / 53.1%). In patients with OC, the radicular cyst was the most frequent (n = 134 / 36.5%), followed by the dentigerous cyst (n = 101 / 27.5%) and the odontogenic keratocyst (n = 52 / 14.2%). Patients with NOC had a higher frequency of epidermoid cyst (n = 12 / 3.3%), oral lymphoepithelial cyst (n = 7 / 1.9%), and nasopalatine duct cyst (n = 4 / 1.1%). The OCs were more prevalent than NOCs, and inflammatory cysts were the most common among all the OCs.

Pediatric Odontogenic and Maxillofacial Bone Pathology: A Global Analysis

BACKGROUND

Although pathology in the maxillary and mandibular bones is rare in young patients, the differential diagnosis is broad. The World Health Organization (WHO) updated its classification of maxillofacial bone pathology in 2017. Using these updated guidelines, a systematic review of common maxillofacial bone lesions in the pediatric population was performed.

METHODS

A PubMed search was conducted capturing English language articles from inception to July 2020. Thirty-one articles were identified that described the frequency of maxillofacial bone pathology. Data were extracted and organized using the WHO 2017 classification of odontogenic and maxillofacial bone tumors. Prevalence data were analyzed among diagnostic categories and geographical regions. The SAS version 9.4 was used to complete statistical analyses.

RESULTS

The articles included patients from birth to a maximum age of 14 to 19 years. The most common odontogenic cysts included radicular cyst (42.7%) and dentigerous cyst (39.0%) followed by odontogenic keratocyst (15.0%). Among odontogenic bone tumors, odontoma (49.3%) was most common followed by ameloblastoma (29.1%). The most common nonodontogenic bone tumor was fibrous dysplasia (42.4%), and the most common malignant bone tumor was osteosarcoma (75.0%). Significant variations were found by geographic region, with dentigerous cyst more common than radicular cyst, and ameloblastoma more common than odontoma in African and Asian countries (P < 0.0001).

CONCLUSIONS

This systematic review uses the WHO 2017 guidelines to classify common odontogenic and nonodontogenic maxillofacial bone lesions around the world. Pathogenesis, presentation, and available treatment options for the most common maxillofacial bone lesions are reviewed.

Langerhans Cells Correlate With Macrophages for Defense Mechanisms in the Atrophic Epithelium of Radicular Cysts

Langerhans cells (LCs) play important roles in cell-mediated immune reactions, as well as in the pathogenesis of periapical lesions. The aim of this study is to evaluate the role of LCs in the proliferative epithelium of radicular cysts (RCs) and the release of the proinflammatory cytokine tumor necrosis factor α (TNF-α) associated with epithelial thickness. Thirty cases of RCs and 30 cases of residual RCs were randomly selected. Morphologic analysis was performed to evaluate the association between the inflammatory infiltrate, cystic epithelial thickness and lesion size, in addition to immunohistochemical assessment of CD1a, CD68, and TNF-α. The highest macrophage percentages and TNF-α scores were found in RCs (P=0.038 and 0.017, respectively). The largest number of LCs was observed in RCs (P=0.021), especially those exhibiting atrophic epithelium (P=0.05). In addition, LCs were positively correlated with the number of macrophages in both RCs and residual RCs (P=0.033 and 0.002, respectively). In contrast to LCs, the largest number of macrophages was detected in cases with an intense inflammatory infiltrate (P=0.022). In addition, the highest TNF-α scores were associated with an intense inflammatory infiltrate (P=0.024) when analyzed in the capsule of RCs (P=0.017). In conclusion, LCs participate in defense mechanisms and were present in all cases evaluated. Along with macrophages, these cells release proinflammatory cytokines such as TNF-α, which is responsible for inducing the continued proliferation of cystic epithelium.

Disinfection of Infected Artificial Dental Periapical Lesions with Diode Laser: An In Vitro Study

Background

Periapical lesions are primarily caused by infections in the root canals. The objective of this study was to assess the antibacterial effectiveness of diode laser during root canal treatment in artificial models of infected periapical lesions.

Material/Methods

One hundred twenty-two extracted premolar single-rooted teeth were inserted into methyl methacrylate artificial models of periapical lesions, and bacterial solutions of Enterococcus faecalis (ATCC 29212) and Streptococcus mitis (ATCC 49456) were then applied to the models. The respective diameters of lesions in the artificial models represented 3 different subgroups based on lesion size. The laser protocol used for endodontic disinfection had a power output of 1.5 W and a wavelength of 810 nm. The impact on cell viability was evaluated by flow cytometry.

Results

Disinfection with laser did not differ between microorganisms (P=0.137), and laser irradiation with a longer duration had better disinfecting action for both microorganisms (P<0.001). Compared with larger lesions, smaller lesions had a higher percentage of dead cells for both microorganisms (P<0.001). The percentage of dead cells in the treatment groups was significantly higher than in the control group (P<0.001).

Conclusions

Laser treatment had a poor, almost negligible effect on elimination of bacterial cells in large periapical lesions. Application of a laser might serve as an adjuvant method to standard irrigation with sodium hypochlorite.

Ultrasound Imaging versus Radiographs in Differentiating Periapical Lesions: A Systematic Review

BACKGROUND

Ultrasonography is a non-invasive method of diagnosing periapical lesions while radiologic methods are more common. Periapical lesions due to endodontic infection are one of the most common causes of periapical radiolucency that need to be distinguished to help determine the course of treatment. This review aimed to examine the accuracy of ultrasound and compare it to radiographs in distinguishing these lesions in vivo.

METHODS

This review process followed the PRISMA guidelines. A literature search of databases (PubMed, Scopus, Embase, and Web of Science) was conducted without any restrictions on time. Articles available in English were included. The selection was done according to the inclusion and exclusion criteria. The QUADAS-2 tool was used to assess the quality of the studies.

RESULTS

The search provided a total of 87 articles, out of which, five were selected for the final review. In all the studies, ultrasound had higher accuracy in distinguishing periapical lesions. All the studies indicated a risk of bias, especially in patient selection.

CONCLUSION

Within limitations, the study indicates that ultrasound is a better diagnostic tool to distinguish periapical lesions compared to radiographs but further studies with well-designed, rigorous protocols and low risk of bias are needed to provide stronger evidence.

Conservative Approach in the Management of Large Periapical Cyst-Like Lesions. A Report of Two Cases

Background and Objectives: Periapical cystic lesions are a pathology frequently addressed to endodontic specialists. Although their therapy is still not standardized, the treatment should be as conservative as possible and by endodontic means, as they are lesions of endodontic origin. The present case report describes two cases of upper central incisors with large cyst-like periapical lesions, and their one-year follow up. Materials and Methods: Endodontic orthograde treatment was performed under copious irrigation with sodium hypochlorite, in association with calcium hydroxide as an intra-canal medication for both teeth. Root canal filling was achieved in a separate appointment using the continuous wave of condensation technique. A decompression procedure was used in association with endodontic therapy in the second case to reduce the pressure inside the cystic lesion and to allow its drainage, and only because the root canal could not be dried three weeks after medication. Initial cone beam computed tomography (CBCT) investigations, as well as at the one-year follow up, were used to compare the evolution of the lesion. Results: Both cases had a favorable outcome. New bone formation in the periapical region and complete resolution of the lesion was observed at the one-year control in the first case. In the second case, although the lesion was still not completely healed at 12 months, a significant reduction in its size could be observed, showing active signs of healing. Conclusions: Endodontic treatment is the first choice option in the management of teeth with pulpal necrosis and large periapical cystic-like lesions. Decompression is the only surgical procedure recommended when the canals cannot be dried and obturated. Large surgical interventions are unnecessary in cases where endodontic treatment can be performed.

An Update of the Possible Applications of Magnetic Resonance Imaging (MRI) in Dentistry: A Literature Review

This narrative review aims to evaluate the current evidence for the application of magnetic resonance imaging (MRI), a radiation-free diagnostic exam, in some fields of dentistry.

BACKGROUND

Radiographic imaging plays a significant role in current first and second level dental diagnostics and treatment planning. However, the main disadvantage is the high exposure to ionizing radiation for patients.

METHODS

A search for articles on dental MRI was performed using the PubMed electronic database, and 37 studies were included. Only some articles about endodontics, conservative dentistry, implantology, and oral and craniofacial surgery that best represented the aim of this study were selected.

RESULTS

All the included articles showed that MRI can obtain well-defined images, which can be applied in operative dentistry.

CONCLUSIONS

This review highlights the potential of MRI for diagnosis in dental clinical practice, without the risk of biological damage from continuous ionizing radiation exposure.

Endodontic Periapical Lesion: An Overview on the Etiology, Diagnosis and Current Treatment Modalities

Nonsurgical and surgical endodontic treatments have a high success rate in the treatment and prevention of apical periodontitis when carried out according to standard and accepted clinical principles. Nevertheless, endodontic periapical lesions remain in some cases, and further treatment should be considered when apical periodontitis persists. Although several treatment modalities have been proposed for endodontically treated teeth with persistent apical periodontitis, there is a need for less invasive methods with more predictable outcomes. The advantages and shortcomings of existing approaches for the diagnosis and treatment of endodontic periradicular lesions are discussed in this review.

Investigation of the effectiveness of CBCT and gray scale values in the differential diagnosis of apical cysts and granulomas

PURPOSE

The aim of this study was to investigate the effectiveness of cone-beam CT (CBCT) findings and gray scale values (GSV) in the differential diagnosis of apical cysts and granulomas.

METHODS

Two independent researchers retrospectively analyzed the CBCT images of 21 teeth and histopathologically diagnosed them as having radicular cysts or apical granulomas. In the CBCT images, apical lesions were evaluated and categorized according to 7 criteria. These criteria were determined as relationship of lesions with dental roots, periphery of the lesion, shape, darker focus in the center, root resorption, displacement in related teeth, and cortical bone perforation. In addition, the minimum and maximum gray scale values of the lesions were measured and compared.

RESULTS

There was a statistically significant relationship between histopathological (HP) diagnosis and well-defined cortical border and lesion shape (p = 0.003, p = 0.014, respectively). According to the HP diagnosis, no statistically significant difference was found among other variables (p > 0.05) CONCLUSION: The presence of a well-defined cortical border or partial cortical border is a distinctive criterion for cysts. Additionally, the shape of the lesion was found to be a significant criterion for the separation of the two lesions. The shape of cystic lesions was circular and apical granulomas had a more curved shape. There was no relationship between the histopathological diagnosis of lesions and CBCT gray scale values.

Healing of Periapical Lesions After Surgical Endodontic Retreatment: A Systematic Review

Background: Surgical root canal retreatment is required when peri-radicular pathosis associated with endodontically treated teeth cannot be treated by non-surgical root canal therapy (retreatment), or when retreatment was ineffective, not feasible or contraindicated. Endodontic failures maybe happen when irritants remain within the confines of the root canal, or when an extra-radicular infection cannot be eradicated by orthograde root canal treatment. Following enhanced microsurgical techniques in the last years, the success rates of surgical root canal retreatment have improved considerably.

Objective: The aim of this systematic review is to gather updated data in regard to the surgical root canal (retrograde) retreatment to heal the periapical lesions.

Materials and methods: The electronic databases PubMed and Google Scholar were searched in this review using specific inclusion and exclusion criteria. The search was performed in June 2019 and updated in November 2019. Among 3900 studies, 10 studies satisfied the eligibility criteria and were included in the review to be analyzed.

Results: The 10 studies showed the importance of surgical root canal retreatment as a treatment option in removing infections within the root canal system and its efficiency in periapical tissue healing. These studies investigated different aspects of healing of periapical lesion after surgical (retrograde) retreatment including success rates, follow-up duration, and updated studies in surgical (retrograde) retreatment.

Conclusions: Surgical root canal (retrograde) retreatment demonstrates its efficiency in reducing the period needed for healing of the periapical lesions in short-term follow-up compared to conventional orthograde retreatment.

Endodontic Surgery Associated with Guided Tissue Regeneration Technique: Case Report

AbstractNon-surgical endodontic retreatment should always be the first option for reintervention when the initial endodontic treatment fails. The surgical treatment, called periradicular surgery, will be the procedure of choice when there is no success after the conventional endodontic retreatment. The purpose of this article is to describe clinical case of endodontic surgery, associated with guided tissue regeneration (GTR). A male patient, 24 years old, was referred for endodontic surgery on tooth 12 after two unsuccessful endodontic interventions. During the surgery, osteotomy, lesion curettage, apicectomy, retrograde obturation with Mineral Trioxide Aggregate (MTA), and filling of the bone failure with lyophilized bone and reabsorbable collagen membrane were performed. After six months of follow-up, the patient did not present any type of painful symptomatology. The endodontic surgery, associated with a technique of guided tissue regeneration, was efficient to solve this clinical case. Keywords: Endodontics. Apicoectomy. Guided Tissue Regeneration. Resumo O retratamento endodôntico não cirúrgico deve sempre ser a primeira opção de reintervenção quando o tratamento endodôntico inicial falha. Já o tratamento cirúrgico, ou cirurgia parendodôntica, será o procedimento de escolha quando não há sucesso após o retratamento endodôntico convencional. O objetivo deste artigo é descrever um caso clínico de cirurgia parendodôntica, associada à regeneração tecidual guiada (RTG). O paciente, gênero masculino, 24 anos, foi encaminhado para cirurgia parendodôntica no dente 12 após duas intervenções endodônticas sem sucesso. Durante a cirurgia foram realizadas manobras de osteotomia, curetagem da lesão, apicectomia, obturação retrógrada com Mineral Trióxido Agregado (MTA), além de preenchimento da falha óssea com osso liofilizado e membrana de colágeno reabsorvível. Após seis meses de acompanhamento do caso, o paciente não apresentou nenhum tipo de sintomatologia dolorosa. A cirurgia parendodôntica, associada à técnica de regeneração tecidual guiada, foi eficiente para solucionar este caso clínico. Palavras-chave: Endodontia. Apicectomia. Regeneração Tecidual Guiada.

Elevated Expression of Macrophage Migration Inhibitory Factor Promotes Inflammatory Bone Resorption Induced in a Mouse Model of Periradicular Periodontitis

Locally produced osteoclastogenic factor RANKL plays a critical role in the development of bone resorption in periradicular periodontitis. However, because RANKL is also required for healthy bone remodeling, it is plausible that a costimulatory molecule that upregulates RANKL production in inflammatory periradicular periodontitis may be involved in the pathogenic bone loss processes. We hypothesized that macrophage migration inhibitory factor (MIF) would play a role in upregulating the RANKL-mediated osteoclastogenesis in the periradicular lesion. In response to pulp exposure, the bone loss and level of MIF mRNA increased in the periradicular periodontitis, which peaked at 14 d, in conjunction with the upregulated expressions of mRNAs for RANKL, proinflammatory cytokines (TNF-α, IL-6, and IL-1β), chemokines (MCP-1 and SDF-1), and MIF's cognate receptors CXCR4 and CD74. Furthermore, expressions of those mRNAs were found significantly higher in wild-type mice compared with that of MIF^-/- mice. In contrast, bacterial LPS elicited the production of MIF from ligament fibroblasts in vitro, which, in turn, enhanced their productions of RANKL and TNF-α. rMIF significantly upregulated the number of TRAP⁺ osteoclasts in vitro. Finally, periapical bone loss induced in wild-type mice were significantly diminished in MIF^-/- mice. Altogether, the current study demonstrated that MIF appeared to function as a key costimulatory molecule to upregulate RANKL-mediated osteoclastogenesis, leading to the pathogenically augmented bone resorption in periradicular lesions. These data also suggest that the approach to neutralize MIF activity may lead to the development of a therapeutic regimen for the prevention of pathogenic bone loss in periradicular periodontitis.

Effect of calcium hydroxide as intracanal medicament on the expression of caspase-9 located within the radicular cyst epithelium

Apoptosis (a programmed cell death mechanism) within the radicular cyst epithelium has still not been correlated with any clinical factor. This study aimed to investigate the effect of calcium hydroxide on apoptosis, via the detection of caspase-9. Thirty radicular cysts collected during apicoectomies and stored in paraffin were retrospectively retrieved. Conservative endodontic treatments had been carried out either without (group (a) n = 14), or with calcium hydroxide application (group (b), n = 16) before obturation. All cysts were immunohistochemically stained for caspase-9 to record apoptosis of the epithelium. Statistical analysis followed. The frequency of caspase-9 immunoreactivity in the cystic epithelium in the two groups was 42.86% and 93.75% of cysts respectively. This difference was statistically significant (P = 0.04 < 0.05). In cysts larger than (or equal to) 10 mm, caspase-9 was more frequently expressed. It was found calcium hydroxide appears to enhance the expression of caspase-9, especially in large lesions.

Oral surgery II: Part 3. Cysts of the mouth and jaws and their management

A cyst may be defined as a pathological (or abnormal) body cavity, usually lined by epithelium, which contains fluid (gas or liquid) or semi-solid substances other than (primarily) pus. Even this definition is contentious, as some pathologists prefer the term pseudocyst or cavity when there is no epithelial lining. However, the above definition, based on that of Kramer, is as inclusive as possible. Cysts of the mouth and jaws are fairly common and their management is an essential component of oral surgery. This third article in the series deals with the classification, diagnosis and management of the common cysts of the head and neck.

Differential diagnosis between a granuloma and radicular cyst: effectiveness of magnetic resonance imaging

AIM

To investigate the diagnostic reliability and accuracy of magnetic resonance imaging (MRI) to differentiate periapical lesions of endodontic origin and to compare the results with histopathological information.

METHODOLOGY

The radiolucent periapical jaw lesions of 34 patients, which were surgically enucleated, were investigated by two radiologists using MRI, based on the same six criteria, to categorize the lesions as granulomas, radicular cysts or others. After apicoectomies, two oral pathologists (blinded to the radiologist's diagnoses) analysed all specimens by referring to seven specific parameters and diagnosed the specimens as granulomas, radicular cysts or other conditions. The inter-rater agreements between the radiologists and pathologists in terms of MRI and histological diagnoses, respectively, along with the discriminant power of the adopted criteria and the accuracy of the MRI assessments compared with the histopathological results, were calculated. Cohen's kappa test was adopted to examine inter-rater agreement between the two radiologists and two pathologists. Guttman's lambda coefficient (λ₆ ) was used to evaluate the internal consistency of the items used for the differential diagnosis by radiologists. The accuracy resulted from a receiver operator characteristic (ROC) analysis.

RESULTS

A strong inter-rater reliability was observed between the two radiologists (k-statistic = 0.86, P = 0.0001) and the two pathologists (k-statistic = 0.88, P = 0.0001). The internal consistency of the diagnostic items was 0.605 for cysts and 0.771 for granulomas. The accuracy (true positives plus true negatives) of the radiologists was greater than that of the pathologists based on analysis (area under the curve = 0.87 and 0.91, respectively).

CONCLUSIONS

The reliability and accuracy of MRI were high and comparable to histopathological reliability, highlighting the usefulness of this noninvasive technique as a pre-treatment diagnostic method for periapical endodontic lesions.

Immunohistochemical Analysis of Galectins-1, -3, and -7 in Periapical Granulomas, Radicular Cysts, and Residual Radicular Cysts

INTRODUCTION

Galectins play important roles in immunoinflammatory responses, but their participation in the development of periapical lesions remains unclear. This study aimed to evaluate the expressions of galectins-1, -3, and -7 in periapical lesions, correlating them with the intensity of the inflammatory infiltrate and the pattern of the cystic epithelium.

METHODS

Twenty periapical granulomas (PGs), 20 radicular cysts (RCs), and 20 residual radicular cysts (RRCs) were submitted to immunohistochemistry using anti-galectin-1, -3, and -7 antibodies. The percentage of immunopositive cells in epithelial and connective tissues was determined.

RESULTS

In connective tissue, PGs exhibited higher cytoplasmic/membrane expression of galectins-1 and -7 than RCs and RRCs (P < .05). There was higher nuclear expression of galectin-1 in PGs compared with RCs and RRCs (P < .05). The expression of galectins-1 and -7 in connective tissue was higher in lesions with grade III inflammation (P < .05). No significant differences in galectin-3 immunoexpression were observed for any of the parameters evaluated (P > .05). In the epithelial component, a higher nuclear expression of galectin-7 was detected in RRCs (P < .05), and a higher cytoplasmic/membrane expression of this protein was found in cysts with hyperplastic epithelium (P < .05). Positive correlations were observed between the nuclear and cytoplasmic/membrane expression of galectin-1 in connective tissue (P < .05) as well as between the nuclear and cytoplasmic/membrane expression of galectin-7 in epithelial tissue of cysts (P < .05).

CONCLUSIONS

Galectins-1 and -7 may play important roles in the pathogenesis of PGs, RCs, and RRCs. On the other hand, the present results suggest only a minor involvement of galectin-3 in the development of these lesions.

Binary Decision Trees for Preoperative Periapical Cyst Screening Using Cone-beam Computed Tomography

INTRODUCTION

Cone-beam computed tomographic (CBCT) analysis allows for 3-dimensional assessment of periradicular lesions and may facilitate preoperative periapical cyst screening. The purpose of this study was to develop and assess the predictive validity of a cyst screening method based on CBCT volumetric analysis alone or combined with designated radiologic criteria.

METHODS

Three independent examiners evaluated 118 presurgical CBCT scans from cases that underwent apicoectomies and had an accompanying gold standard histopathological diagnosis of either a cyst or granuloma. Lesion volume, density, and specific radiologic characteristics were assessed using specialized software. Logistic regression models with histopathological diagnosis as the dependent variable were constructed for cyst prediction, and receiver operating characteristic curves were used to assess the predictive validity of the models. A conditional inference binary decision tree based on a recursive partitioning algorithm was constructed to facilitate preoperative screening.

RESULTS

Interobserver agreement was excellent for volume and density, but it varied from poor to good for the radiologic criteria. Volume and root displacement were strong predictors for cyst screening in all analyses. The binary decision tree classifier determined that if the volume of the lesion was >247 mm³, there was 80% probability of a cyst. If volume was <247 mm³ and root displacement was present, cyst probability was 60% (78% accuracy).

CONCLUSIONS

The good accuracy and high specificity of the decision tree classifier renders it a useful preoperative cyst screening tool that can aid in clinical decision making but not a substitute for definitive histopathological diagnosis after biopsy. Confirmatory studies are required to validate the present findings.

Successful Nonsurgical Management of Periapical Lesions of Endodontic Origin: A Conservative Orthograde Approach

Periapical lesions of endodontic origin are common pathological conditions affecting periradicular tissues. Microbial infection of pulpal tissues is primarily responsible for initiation and progression of apical periodontitis. The primary objective of endodontic therapy should be to restore involved teeth to a state of normalcy nonsurgically. Different nonsurgical management techniques, namely, conservative root canal therapy, decompression technique, method using calcium hydroxide, aspiration-irrigation technique, lesion sterilization and tissue repair therapy, active nonsurgical decompression technique, and the apexum procedure have been advocated. New techniques which use drug-loaded injectable scaffolds, simvastatin, and epigallocatechin-3-gallate have been tried. Surgical option should be considered when intra- or extra-radicular infections are persistent. Incidence of nonendodontic periapical lesions has also been reported. An accurate diagnosis of the periapical lesion whether it is of endodontic or nonendodontic origin has to be made. Surgical methods have many disadvantages, and hence should be considered as an option only in the case of failure of nonsurgical techniques. Assessment of healing of periapical lesions has to be done periodically which necessitates a long-term follow-up. Even large periapical lesions and retreatment cases where the lesion is of endodontic origin have been successfully managed nonsurgically with orthograde endodontic therapy.

Management of Cyst-like Periapical Lesions by Orthograde Decompression and Long-term Calcium Hydroxide/Chlorhexidine Intracanal Dressing: A Case Series

Cyst-like periapical lesions should be treated initially with conservative nonsurgical procedures. In this case series, we describe the clinical and radiographic outcomes of large cyst-like lesions that were treated by orthograde decompression and long-term intracanal use of calcium hydroxide [Ca(OH)2] mixed with 2% chlorhexidine digluconate. Ten cases of cyst-like periapical lesions involving 15 teeth from 10 patients were selected. Maximal radiographic diameters of the lesions ranged from 11 to 28 mm. Nonsurgical procedures were performed, including apical patency, orthograde puncture of cyst-like exudates, chemomechanical preparation, and placement of intracanal Ca(OH)2/CHX dressings, which were periodically replaced during 6-10 months. The root canals were then filled with gutta-percha and sealer. The follow-up periods ranged from 6 to 24 months, and the outcome was classified as healed, healing, or failure. Nine lesions drained copious exudates after canal patency. One lesion only drained bloody serous exudate after periapical overinstrumentation. In 9 patients, intracanal exudation ceased in the first follow-up visit. At the 24-month follow-up, 6 lesions (60.0%) had healed, and 3 lesions (30.0%) were healing, with the corresponding patients being without clinical signs or symptoms. The case of treatment failure was submitted to surgical treatment. Microscopically, the lesion appeared to be an apical cyst with exuberant extraradicular bacterial biofilms attached to the sectioned root apex. This case series supports the use of nonsurgical methods to resolve larger cyst-like periapical lesions.

Large Periapical or Cystic Lesions in Association with Roots Having Open Apices Managed Nonsurgically Using 1-step Apexification Based on Platelet-rich Fibrin Matrix and Biodentine Apical Barrier: A Case Series

Teeth having open apices in the absence of a natural apical constriction pose several challenges during conventional endodontic treatment, especially when establishing an apical seal. Treatment is further challenging when these teeth are associated with large periapical or cystic lesions having resulted in expansion and/or thinning of adjacent cortical plates. Although surgical intervention is commonly adopted in the management of such cases, a conservative treatment option offering equally good prognosis is always desirable. This case series describes 3 cases: a 39-year-old woman, a 45-year-old woman, and a 15-year-old boy having teeth with concomitant open apices and large periapical/cystic lesions managed conservatively by (1) following a strict intracanal disinfection protocol, (2) intracanal aspiration with digital decompression of associated swelling, and (3) 1-step apexification for closure of the root apex by placing a preliminary barrier of platelet-rich fibrin (PRF) and a secondary barrier of Biodentine (Septodont, Saint-Maur-des-Fossés, France). In all 3 cases, the treatment outcomes, both clinical and radiographic, were highly satisfactory. PRF and Biodentine collectively rendered an apical plug that proved to be a suitable alternative to commonly used mineral trioxide aggregate in 1-step apexification. Biodentine provides good interfacial adhesion and sealing with dentin attributed to its property of hydroxyapatite crystal deposition at the material-dentin interface. Also, because of its bioactivity, it likely promotes the conversion of adjacent PRF into a calcific barrier, thus reinforcing the apical seal. Additionally, host-modulating responses of PRF contribute in expediting the healing process. Reasonable osseous healing in the periapex could be appreciated as early as 3 months in all patients. The rapidity with which healing occurred may have been an incidental finding but definitely draws attention.

M2 macrophages coexist with a Th1-driven profile in periapical cysts

AIM

To evaluate the participation of both Th1 and Th2 responses in periapical cysts by assessing the presence of M2 macrophages, as well as acute IL-1 β, TNF-α and IL-6 cytokines.

METHODOLOGY

Twenty-four cases of periapical cysts were selected. Immuno-expressions of IL-1 β, IL-6, TNF-α and CD163 were analysed in the cystic capsules in both superficial and deeper regions. Data were analysed with paired Wilcoxon test and Spearman correlation coefficient (P ≤ 0.05).

RESULTS

There was a higher expression of IL-1β, IL-6, TNF-α and M2 macrophages in the superficial region (P < 0.001) of cystic capsules. All acute cytokines had significant positive correlations amongst them regardless of the cystic capsule region. Regarding CD163, positive correlations occurred only with TNF-α (P = 0.007; r = 0.537) and IL-6 (P = 0.018; r = 0.478) in the superficial regions of the cystic capsule.

CONCLUSIONS

M2 macrophages participated actively in the inflammatory response of periapical cysts and correlated with the expression of certain acute Th1-related cytokines. This illustrates the coexistence of an acute and chronic Th2-driven immune response in these lesions. Although M2 macrophages favour the healing process, their presence is not sufficient for periapical cyst regression, once an acute active response has occurred due to an infectious stimuli.

Differential diagnosis of periapical cyst using collagen birefringence pattern of the cyst wall

Objectives

Periapical lesions, including periapical cyst (PC), periapical granuloma (PG), and periapical abscess (PA), are frequently affected by chemical/physical damage during root canal treatment or severe bacterial infection, and thus, the differential diagnosis of periapical lesions may be difficult due to the presence of severe inflammatory reaction. The aim of this study was to make differential diagnosis among PC, PG, and PA under polarizing microscope.

Materials and Methods

The collagen birefringence patterns of 319 cases of PC (n = 122), PG (n = 158), and PA (n = 39) obtained using a polarizing microscope were compared. In addition, 6 cases of periodontal fibroma (PF) were used as positive controls.

Results

Collagen birefringence was condensed with a thick, linear band-like pattern in PC, but was short and irregularly scattered in PG, and scarce or absent in PA. PF showed intense collagen birefringence with a short, palisading pattern but no continuous band-like pattern. The linear band-like birefringence in PC was ascribed to pre-existing expansile tensile stress of the cyst wall.

Conclusions

In this study all PCs (n = 122) were distinguishable from PGs and PAs by their characteristic birefringence, despite the absence of lining epithelium (n = 20). Therefore, the authors suggest that the presence of linear band-like collagen birefringence of the cyst wall aids the diagnostic differentiation of PC from PG and PA.

Cone Beam CT in Diagnosis and Surgical Planning of Dentigerous Cyst

Diagnosis and preoperative planning are critical in the execution of any surgical procedure. Panoramic radiography is a routine method used in dentistry to assist clinical diagnosis; however, with this technique 3D anatomical structures are compressed into 2D images, resulting in overlapping of structures which are of interest in the diagnosis. In this study we report the case of a patient who presented with a dentigerous cyst of expressive dimensions in the body of the mandible region. The surgery was planned and executed after observing the margins of the lesion by Cone Beam Computed Tomography (CBCT). We conclude that CBCT is a precise method to help diagnosis; it provides greater accuracy in surgical treatment planning through 3D image display, allowing more effective results.

Nonsurgical endodontic treatment of teeth associated with large periapical lesion using triple antibiotic paste and mineral trioxide aggregate apical plug: A case series

Periapical diseases are induced as a result of the direct or indirect involvement of oral bacteria. The etiologic factor being the degenerating pulp tissue. A periapical lesion is formed within an area of apical periodontitis which cannot form by itself and is inflammatory in origin. If the microbial etiology of periapical lesions and in the root canal is removed by nonsurgical root canal therapy the lesions regress. Mere surgical removal of the periapical lesions without proper root canal disinfection and obturation will not result in the healing of periapical tissues. Nonsurgical treatment with triple antibiotic paste offers a high success rate in the healing of large periapical lesions. The present clinical cases show the nonsurgical endodontic management of large periapical pathosis using triple antibiotic paste and mineral trioxide aggregate.