Persistent Periapical Lesions Research Articles

Impact of diabetes mellitus on endodontic treatment outcomes

Diabetes mellitus (DM) is a chronic metabolic disorder that affects various systemic functions, including oral health. Its impact on endodontic treatment outcomes has become a significant concern for dental practitioners. The relationship between DM and endodontic outcomes is complex, involving several pathophysiological mechanisms. Hyperglycemia leads to the formation of advanced glycation end-products, causing vascular dysfunction and impaired blood supply to the pulp, which exacerbates pulpal inflammation and increases the risk of necrosis. Additionally, chronic low-grade inflammation and an impaired immune response in diabetic patients contribute to a higher susceptibility to infections, delayed healing, and compromised tissue repair after endodontic procedures. Diabetic patients often experience lower success rates and prolonged recovery following endodontic treatment due to these systemic challenges. Reduced bone healing, persistent periapical lesions, and altered microbial flora are common complications that can hinder treatment success. Effective management of endodontic treatment in diabetic patients requires a multifaceted approach that includes strict glycemic control, the use of enhanced antimicrobial strategies, and the adoption of minimally invasive techniques to reduce tissue trauma. Additionally, patient education and close monitoring of the healing process are essential for minimizing complications. Understanding the pathophysiological interactions between diabetes and pulpal inflammation, as well as the factors that influence healing and success rates, is crucial for optimizing endodontic care in diabetic patients. By addressing both systemic and local factors, dental practitioners can improve the prognosis of endodontic treatment and ensure better outcomes for patients with diabetes. Ongoing research into the mechanisms underlying these complications will further enhance the ability of clinicians to manage endodontic cases effectively in this growing patient population.

Nonsurgical endodontic retreatment: A series of four case reports

The primary objective of endodontic treatments or any pulp therapy is to maintain the integrity and health of oral tissues. Endodontic treatments aim to disinfect and shape the root canal system completely and obturate it in 3D to prevent reinfection. Although initial root canal therapy has high success rates, failures can occur. The term ‘retreatment’ denotes a new intervention to retain the tooth in the oral cavity. Nonsurgical endodontic retreatment can preserve previously treated teeth with persistent periapical lesion(s), if the tooth is restorable and periodontally sound, and patient wants to keep it. The clinician and patient should select the treatment with the best long-term outcome. This case series describes endodontically treated teeth that required nonsurgical endodontic retreatment due to inadequate obturation, persistent periradicular lesion and loss of coronal seal.

The relationship between severity of periapical periodontitis and next-generation systemic inflammatory biomarkers in children with early childhood caries

IntroductionEarly childhood caries (ECC) is closely associated with poor oral hygiene and cariogenic diet. Untreated ECC results in recurrent odontogenic infections and local and systemic consequences. In this study, our goal is to assess the relationship between the intensity of odontogenic infection-associated periapical periodontitis and new generation of systemic inflammatory markers (SII, NLR, PLR) in ECC-affected children.Material and method95 healthy patients in early childhood and demonstrating periapical periodontitis who underwent dental treatment under general anesthesia (GA) in the last two years were included in the present study. Their periapical statuses were dichotomized as mild and severe. Periapical Index (PAI) scores of 2 and 3 were regarded as “mild” whereas 4 and 5 as “severe”. Of the complete blood test (CBC) parameters, systemic inflammatory index (SII), neutrophil-to-lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), neutrophilic granulocyte (NEUT), lymphocyte (LYMPH) and platelet (PLT) were recorded. The relationship between the degree of periapical pathology and the evaluated markers was assessed using Receiver Operating Characteristic (ROC) analysis.ResultsResults of the present study revealed that mean NLR, SII and NEUT index scores of the patients having severe periapical periodontitis were statistically higher than those of the ones with mild pathology (p < 0.05). A positive, statistically significant interrelationship was found between the number of teeth demonstrating a PAI score of severe periapical periodontitis with the signs of exacerbation (PAI 5) and NLR and SII values (p < 0.05). Area under the ROC curve (AUC) values for NLR and SII were determined as 66.8% and 66.6% respectively, indicating that classification performance was sufficient and statistically significant (p < 0.05).ConclusionPostponing the management of odontogenic infections will induce some complications such as, infective endocarditis and cause the systemic inflammatory process to continue by aggravating the systemic effects of local lesions. Thus, underlying mechanism should be eliminated and oral hygiene should be maintained, also novel biomarkers may be recommended to be used for the decision-making process for the teeth with persistent periapical lesions unresponsive to treatment.

Combined endodontic and regenerative periodontal therapy for managing questionable mandibular anterior teeth with radicular cysts

Abstract Endodontic microsurgery (EMS) presents a great treatment option for unresolved periradicular pathologies, typically involving the removal of the apical root portion and adjacent inflamed tissues. This case report describes the management of persistent periapical lesions in the lower anterior teeth of a 32-year-old male. Root canal treatment was completed 4 years before presentation. The patient presented to the clinic with tooth mobility and mild discomfort and large radiographical periapical radiolucency. The case was diagnosed with previously treated with asymptomatic apical periodontitis. EMS was performed in conjunction with periodontal-guided tissue regeneration that includes bone graft and resorbable membrane and the teeth showed favorable resolution of the symptoms. Histopathological analysis showed the presence of a radicular cyst. After 3 years of follow-up, cone-beam computed tomography and periapical radiographs demonstrated substantial lesion regression and favorable outcome. This case report offering promising insights into the synergistic potential of combined endodontic and regenerative periodontal therapy in cases with unresolved periapical lesion with extensive bone destruction.

Can antimicrobial photodynamic therapy serve as an effective adjunct protocol for disinfecting the necrotic root canal system? A randomized controlled study

BackgroundBacterial infection plays an important role in persistent periapical lesions and inadequate disinfection of root canals is considered the biggest factor responsible for endodontic treatment failure. Antimicrobial Photodynamic Therapy (aPDT) has become the latest choice to eradicate microorganisms in root canals.ObjectiveThis study aims to evaluate the effectiveness of Antimicrobial Photodynamic Therapy (aPDT) in bacterial count reduction compared to Passive Ultrasonic Activation (PUI) and Ca(OH)2 dressings.Materials and methodsForty-five anterior single canal teeth with medium-sized periapical lesions (2–5 mm) were divided into three groups according to the disinfecting technique (each group consists of 15 canals with 1:1:1 allocation ratio): Group A: Ca(OH)2 dressing. Group B: Passive Ultrasonic Activation (PUI). Group C: Antimicrobial Photodynamic Therapy (aPDT). Direct bacterial viable count method was used to count the colonies forming units (CFU) before and after the disinfecting and the bacterial count reduction was estimated, the statistical analysis was performed at a 95% confidence level using the Chi-square and Mann–Whitney U test.ResultsaPDT showed no statistically significant difference when compared to passive ultrasonic irrigation (P > 0.05) but showed higher and more promising results when compared to Ca(OH)2 dressings (P < 0.05).ConclusionsaPDT has the ability and effectiveness as a disinfecting technique in necrotic and infected root canals.Clinical significance of the studyThe results of this clinical trial provide that aPDT can be considered an adjunct method for root canal disinfection with the same effectiveness as passive ultrasonic irrigation.

Mutational analysis of cytoplasmic domain of integrin subunit alpha-1 and its association with periapical wound healing after surgical endodontic treatment.

Numerous studies reported that the healing after surgical endodontic retreatment is influenced by multiple factors which include the genetic profile of the patient, epigenetics, and immune responses. The genes which are primarily responsible for the healing potential in different individuals are those which are involved in the regulation of the cytoskeleton and cellular adhesion which subsequently affects bone deposition and healing. Integrins are cell-surface molecules, possess a key role in the cytoskeleton and cellular adhesion. Integrin Subunit Alpha 1 (ITGA1) is one among the integrin family and helps in regulating the Epidermal Growth Factor receptor (EGFR) pathway, consequently affects proliferation and healing. The objectives of the study were to identify mutations in the cytoplasmic domain of Integrin Subunit Alpha 1 (ITGA1), to assess the expression of activated EGFR, EGFRPhospho and TC-PTP in the periapical wound and to correlate these mutations and expression patterns with periapical wound healing. Thirty-seven patients between ages 18-60 years reported chronic apical periodontitis of single-rooted anterior teeth with periapical radiolucency, equal or greater than 4 mm or periapical lesion in an open apex of single-rooted teeth due to trauma were included in the study from 01st June 2018 till 31st October 2019. Patients with persistent radiolucency after primary root canal treatment and endodontic retreatment were kept on follow-up for 3-4 months surgical endodontic treatment was performed in cases with persistent periapical lesions of 4mm or more in diameter. Periapical lesion sample was collected and used for (1) histo-pathological analysis after Hematoxylin & Eosin staining, (2) total DNA extraction for ITGA1 cytoplasmic domain mutational analysis and immunohistochemistry for EGFR and TCPTP. A positive correlation was observed between the expression levels of EGFRPhospho and the healing of periapical lesions. Moreover, a negative weak correlation was observed between the expression levels of EGFR and TCPTP and the healing of periapical lesions. Out of nine sequences of cytoplasmic domain of ITGA1 which were analyzed, none of them was detected with SNP. Higher expression levels of EGFRPhospho and lower expression levels of EGFR and TCPTP were associated with patients with good healing potential in periapical area. However, immunohistochemistry scores were statistically insignificant to draw any conclusion.

The Effectiveness of Autologous Platelet Concentrates in the Clinical and Radiographic Healing after Endodontic Surgery: A Systematic Review.

Regenerative techniques are increasingly applied in endodontic surgery, but different materials may have varying impacts on soft and hard tissue healing. This systematic review aims to evaluate the effectiveness of autologous platelet concentrates (APCs) in clinical and radiographic healing after endodontic surgery. The data for this systematic review were processed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for improving the reporting of systematic reviews and meta-analyses. A literature search was conducted until October 2023 on PubMed, Scopus, and Cochrane Databases. Randomized controlled trials and controlled clinical trials addressing the use of APCs in patients who presented persistent periapical lesions and needed periapical surgery were included. Dual publications, narrative reviews, systematic reviews, case series, questionnaires, animal studies, case reports, letters to the editor, in vitro studies, and abstracts were excluded. In total, the search resulted in 14 papers. Clinical and radiographical findings were reported, showing that when APCs were used, patients exhibited less pain and swelling and a greater reduction of apical radiolucency after 12 months follow-up on average. However, the moderate/high risk of bias of included studies and their high heterogeneity, do not allow one to draw definitive conclusions on the effectiveness of APC after endodontic surgery.

Piezoelectric Endodontic Microsurgery with Modified Cortical Window Technique: A Case Report

Osteotomy in endodontic microsurgery for teeth with periapical lesions which have not perforated the cortical plate can be a complex procedure especially if anatomical structures such as the mental nerve are close to the area of ​​surgical intervention. For such cases, the cortical bone window technique is an excellent option to access the operating field, preserving the cortical bone and avoiding the use of other bone regeneration materials. The present case documented the use of the cortical bone window technique with a modification, due to the proximity of the mental nerve to approach a persistent periapical lesion of a mandibular second premolar with previous endodontic treatment. Cone beam tomography (CBCT) and intraoral scanning were used for planning and elaboration of a navigation guide for surgical procedure. The clinical and radiographic 5-month follow-up with periapical radiography and CBCT revealed a favorable outcome, with an asymptomatic patient and an advanced healing process at the previous periapical lesion site.

Reduction of NrF2 as coadjuvant during the development of persistent periapical lesions.

Persistent periapical lesions (PPL) are the result of pulpar necrosis induced by bacterial infection resulting in bone degradation and culminating with the loss of dental piece. Pathological changes in the peripapice are associated with the presence of free radicals. The transcription factor Nrf2 is the main regulator of the endogenous antioxidant response against oxidative stress and has been implicated in the regulation of osteoclastogenesis.The aim is to determine the oxidative condition in samples from patients with Persistent Periapical Injuries as a detonating factor of tissue damage. An observational, descriptive, cross-sectional study was carried out in samples with PPL (cases) and samples by removal of third molars (controls) obtained in the clinic of the specialty in endodontics, University of Guadalajara. Samples were submitted to histological staining with Hematoxylin-Eosin, lipoperoxide analysis, Superoxide Dismutase (SOD), Glutathione-Peroxidase (GPx) and Catalase (CAT) activities were determined by immunoenzymatic assays and NrF2 by Western Blot analysis. Samples from PPL patients histologically showed an increased presence of lymphocytes, plasma cells, and eosinophils, as well as a decrease in extracellular matrix proteins and fibroblast cells. There was a rise in lipid peroxidation, GPx and SOD activities, but an important decline (36%) in Catalase activity was observed (p<0.005); finally, NrF2-protein was diminished at 10.41%. All comparisons were between cases vs controls. The alterations in antioxidants endogenous NrF2-controlled are related to osseous destruction in patients with PPL.

Antibacterial Efficacy of Polymer-Coated Ceramic Microparticles Loaded with a Modified Combination of Antibiotics on the Enterococcus faecalis Biofilm.

Nano-technology applied for the local delivery of different agents and/or drugs has made its path to endodontics. In the current study, the antibacterial efficacy of biopolymer-coated ceramic microparticles loaded with a modified combination of triple antibiotics, i.e. Penicillin G, Metronidazole and Ciprofloxacin (PMC), was evaluated against two strains of Enterococcus faecalis (E.faecalis); a standard clinical strain obtained from previously root-filled teeth with persistent periapical lesions, and compared to the most common antimicrobials used in endodontics. After synthesis of the polymer-coated microparticles loaded with antibiotics, the 21-day release of antibiotics were evaluated and a stock solution was produced using the maximum released amount of drugs and distilled water. The antibacterial activity of PMC, triple antibiotic paste (TAP), calcium hydroxide (CH), chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against two bacterial strains was determined using "Minimum Inhibitory Concentration" and "Agar Diffusion Test". Additionally, "Microtiter Plate Assay" was performed to assess anti-biofilm properties. Minimum inhibitory concentration values reported for TAP and PMC were 1/256. PMC showed the maximum diameter of growth inhibition in both strains (33 mm and 35 mm), while CH had the minimum diameters (13 mm and13 mm). Based on microtiter plate assay, TAP showed higher biofilm formation than PMC. Biofilm formation was higher in the standard strain for PMC; however, NaOCl, CHX and CH completely inhibited biofilm formation. Based on the findings of the present study, it could be concluded that PMC and TAP were the most effective medicaments against E.faecalis in its planktonic form; however, none could inhibit its biofilm formation. Further studies using larger sample size and "Confocal Scanning Laser Microscopy" are recommended.

Outcome and success rate of dental autotransplantation: A long‐term evaluation of 144 teeth

Aim To evaluate a sample consisting of 144 autotransplanted teeth performed in 128 patients, which were subjected to periodic follow-up from 6 months to 23 years. Materials and methods The sample consists of 33 molars, 91 premolars, 4 canines and 16 incisors. Clinical and radiographic examinations were performed every 6 months since the day of transplantation. In the last follow-up visit, successful autotransplantation should present the following: absence of active inflammatory root resorption and ankylosis; crown/root ratio <1 (root size higher than crown size); radiographic evidence of additional root growth (in case of partly formed root grafts); absence of tooth mobility, periodontal disease and persistent periapical lesions after endodontic treatment. The success rate was acquired by percentage of transplanted teeth that met the criteria in relation to the total number of transplanted teeth in the sample. Statistical tests were performed as indicators of success. Results The evaluation showed a 93% success rate for the completion of autotransplanted teeth. Eight teeth showed inflammatory root resorption and five teeth, ankylosis. The success rate of molars was 91% and canines was 100%. All variables presented statistical p value of <0.05, except for tooth colouration, root development, donor site and recipient site. Conclusion These findings support that tooth autotransplantation is a reliable treatment and preferred solution for early tooth loss in children and young patients. Furthermore, it demands the professionals the correct evaluation as well as to create the necessary conditions regarding the site receptor, tooth to be transplanted, quality of the surgical procedure, aesthetic complement and periodic control of each case.

NON-SURGICAL MANAGEMENT OF A LARGE CYSTIC LESION WITH SURGICAL DECOMPRESSION: A CASE REPORT WITH 14 MONTHS FOLLOW UP

The main aim of this case report was to report the clinical efficacy of decompression for treating large periapical lesions. Tooth with large periapical cystic lesions were treated with decompression after root canal treatment. A conventional decompression technique such as aspiration/irrigation technique was used in this case. An 18-G needle with a syringe was used to aspirate the cystic lesion. Two needles were then inserted into the lesion copious saline irrigation was delivered from 1 needle and until clear saline was expressed from the other. Complete enucleation and root-end surgery was not done in the case. Healed lesions or lesions in healing were observed after 14 months. On the basis of the presented case and published case reports regarding large periapical cystic lesions, conservative decompression may be used for certain cases before or in lieu of apical surgery. Decompression enables healing of large, persistent periapical lesions after root canal treatment.

Surgical management of a persistent periapical lesion using cone-beam computed tomography

Endodontic therapy has a high success rate. However, failed endodontic therapy with persistent periapical lesions may indicate the presence of an apical cyst that requires surgical apical intervention. The present case involved a 70-year-old woman who was referred after initiation of nonsurgical root canal treatment (NSRCT) in the upper left lateral incisor (tooth #22); due to recurrent swelling and sinus tract. Periapical radiographs showed an apical radiolucency on tooth #22. In a clinical examination, tooth #22 showed a normal response to cold and the electric pulp tester (EPT), while the upper left canine (tooth #23) showed a negative response to cold and the EPT. NSRCT was performed for tooth #23. Eighteen months later, the patient presented with the same chief complaint of recurrent swelling, and cone-beam computed tomography was performed to examine the extent of the apical lesion and plan for surgical intervention. Apical surgery was performed using a dental operating microscope. At the 18-month follow-up assessment, the patient's radiographs showed good bone healing and symptom resolution. This case report indicates that some cases with large persistent periapical lesions may require surgical intervention.

Various Assisted Bone Regeneration in Apicectomy Defects Systematic Review and Meta Analysis.

Introduction:In the endodontic surgery, the common applications are the procedures that apply regenerative methods. There are various methods that help in the regeneration after the endodontic root end cutting or apicectomy. The outcome of the apicectomy depends on the procedure and the material. Hence in the present study, we intend to conduct the systemic review and meta-analysis of the various assisted bone regeneration in apicectomy defects.Materials and Methods:The study was conducted by the online search of the data that included the studies for the regenerative procedure in the endodontic surgery in patients with various periapical pathologies. The data search engines were Scopus, Web of Science, Google Scholar, and PubMed. The risk of the bias was calculated. The study participants were divided into case and control groups. Case group had undergone the regenerative surgery for the persistent periapical lesions, while the control group had not undergone the regenerative surgery for the persistent periapical l. The clinical and the radiograph outcomes were compared between the control and the case groups. Meta-analysis was done and the subgroups were evaluated.Results:From a total of 1561 articles, only 11 were finalized for the study to conduct the meta-analysis. The bias was noted for majority of the studies most of which were clinical trials. It was observed that the regenerative methods used in the endodontic surgery have significantly improved the outcome. The application of the expanded polytetrafluoroethylene only has no significant effect; however, application of the autologous platelet concentrates or collagen membranes only had good outcomes. The combination of the materials showed a significant outcome than when applied alone.Conclusions:From this meta-analysis, it is evident that regenerative procedures are beneficial in the endodontic apicectomy procedures. The materials used in these procedures will augment the outcome. A better prognosis is expected if the combination of the materials is used.

Retrograde filling material in periapical surgery: a systematic review.

Background Periapical surgery focuses on the treatment of teeth with persistent periapical lesions when orthograde root canal treatment fails. Although MTA® is the gold standard material for retrograde filling, Biodentine® - a tricalcium silicate-based cement - has been proposed in order to resolve several of its limitations. A systematic review has been carried out to compare the physicochemical properties of Biodentine® versus MTA® as root-end filling material in periapical surgery. Material and Methods An electronic search was conducted by two independent examiners during March 2020 in the Cochrane, PubMed-MEDLINE and Scopus databases. In addition, a manual search was made in specialized journals. Comparative human or in vitro studies that evaluated bond strength, the presence of marginal gap and sealing ability were included. No restriction on publication date was applied. Animal studies, clinical cases, cases series and expert opinions were excluded. Results After analyzing 147 initially selected studies, 13 publications were included. Regarding bond strength, the studies seemed to evidence better performance of Biodentine® in both acidic and blood contaminated environments. In relation to the presence of marginal gap and sealing ability, the studies yielded contradictory results. According to some authors, the sealing ability of Biodentine® is greater than that of MTA® during the first 24 hours, though both materials prove equal after one week. Other authors recorded no significant differences. Conclusions Considering the limitations and heterogeneity of the studies included, there is not sufficient evidence to confirm the clinical superiority of Biodentine® as a root-end filling material in periapical surgery. Key words:Biodentine, MTA, retrograde filling, periapical surgery.

Impact of different regenerative techniques and materials on the healing outcome of endodontic surgery: a systematic review and meta-analysis.

Regenerative techniques are increasingly applied in endodontic surgery, but different materials used in regenerative techniques may have varying impacts on wound healing. This study evaluated the effects of different regenerative techniques and materials on the outcome of endodontic surgery. patients with persistent periapical lesions, treated with root-end surgery. endodontic surgery without the use of regenerative techniques/materials. endodontic surgery with the use of regenerative techniques/materials. combined clinical and radiographic results. PubMed, Web of Science, Embase, SinoMed and the CENTRAL Cochrane were searched up to 10th July 2020, followed by a manual search. Detailed eligibility criteria were applied. Cochrane's risk-of-bias tool 2.0 was used to assess the risk of bias of the eligible studies. Meta-analysis was conducted using RevMan software. Subgroup analyses were performed based on the regenerative materials used in endodontic surgery. Eleven eligible randomized controlled trials (RCTs) were included in the meta-analysis: two had a low risk of overall bias, and nine had some concerns of overall bias. Generally, the use of regenerative techniques significantly improved the outcome of endodontic surgery (risk ratio [RR]: 0.42; 95% confidence interval [CI], 0.26-0.68; P<0.001). On subgroup analysis, the use of expanded polytetrafluoroethylene (e-PTFE) membranes alone had no added benefits (RR: 2.00; 95% CI, 0.22-18.33; P=0.54). The application of collagen membranes or autologous platelet concentrates (APCs) alone was associated with a trend for better outcomes (RR: 0.51; 95% CI, 0.20-1.25; P=0.14) (RR: 0.55; 95% CI, 0.18-1.71; P=0.30). The combined use of collagen membranes and bovine-derived hydroxyapatite significantly improved the outcome (RR: 0.35; 95% CI, 0.17-0.75; P=0.007). This systematic review evaluated the effects of collagen membranes, e-PTFE membranes, APCs and bone grafting materials, providing detailed information about the risks and benefits of using each regenerative technique/material or its combination in endodontic surgery. Regenerative techniques improve periapical lesion healing after endodontic surgery. The combined use of collagen membranes and bovine-derived hydroxyapatite may be beneficial as an adjunct to endodontic surgery. In contrast, the positive efficacy of e-PTFE membranes or APCs alone remains doubtful.

Assessment of Antibacterial and Antifungal Properties of Root-End Filling Materials

Aim: This study aimed to assess the antimicrobial activity of MTA repair (Angelus®), Biodentine (Septodont®), and IRM(Densply®) in microorganisms isolated from the persistent periapical lesion. Materials and Methods: The microorganisms isolated were tested by Minimum Inhibitory Concentration (MIC): 50 µl of saline solution and 100 µl of MTA repair, Biodentine and IRM were used to perform the following dilutions of 1: 2, 1: 4, 1: 8, 1:16, 1:32, 1:64, 1: 128, 1: 256, 1: 512, 1: 1024. After the inoculation of the microorganisms. The culture of S. mitis was carried out on Müeller Hinton agar plates with sheep blood and for C. albicans, sabouraud agar plates, and Chromogenic candida agar Then, incubated at 37 °C for 24 h. To assess their growth Results: For C. albicans MTA repair demonstrated growth at 1:64 dilution, Biodentine: 1: 512 dilution, and IRM: 1: 1024 dilution. For S. mitis Biodentine, MTA repair and IRM demonstrated growth at: 1: 1024 dilution. Conclusion: MTA repair (Angelus) Biodentine (Septodont) and IRM were effective inhibiting C. albicans and S. mitis at their original concentrations, however, IRM and Biodentine had a greater antifungal effect than MTA when subjected to higher dilutions.

Intentional replantation - a clinical review of cases undertaken at a major UK dental school.

Introduction Intentional replantation (IR) may offer a solution for persistent periapical lesions associated with endodontically treated teeth in select cases. This case series demonstrates the use of IR as an alternative treatment approach to both orthograde and surgical endodontic retreatment. The indications, contraindications, benefits and risks of IR are discussed, and the clinical procedure is outlined.Setting Restorative Department, University Dental Hospital of Manchester, UK.Case reports Of the 13 cases presented, the follow-up period before discharge ranged from 3-28 months. Only one tooth which presented intra-operative challenges required extraction three months after IR due to post-operative mobility.Conclusion In select cases, IR may provide a simple, less invasive and cost-effective alternative to both endodontic retreatment and extraction alone following appropriate training.

EVALUATION OF BONE HEALING AFTER APICAL RESECTION BY ULTRASONOGRAPHY

<h3>Background</h3> Apical resection is a reliable method for the treatment of teeth with persistent periapical lesions or in cases where nonsurgical treatment is not successful. Generally, outcome assessment of apical resection is based on 2-D periapical radiographs. Ultrasound imaging is based on reflection of sound waves at the interface between 2 different tissues and is also recognized as the most risk-free imaging modality. <h3>Objective(s)</h3> Our aim was to evaluate healing of bone after apical resection by using ultrasonography. <h3>Study Design</h3> Ethical approval and patient consent were obtained. Three patients with periapical lesions of endodontic origin were examined with cone beam computed tomography (CBCT) and ultrasonography before surgery. ACUSON S 2000 color Doppler ultrasonography unit with 15 MHz intraoperative probe was used to obtain ultrasound images. In all patients, root canal treatment and apical resection surgery were performed. In 1 patient, during apical surgery, bone graft (Creos Greft, Nobel Biocare Services AG, Zurich, Switzerland) and resorbable collagen membrane (Creos xenoprotect, Nobel Biocare Services AG, Zurich, Switzerland) were used. The other cases were left to secondary healing. Three months after apical resection, periapical radiographs and ultrasonographic examination were performed for follow-up assessment. <h3>Results</h3> The resection area was filled with bone, and hyperechogenic bone healing was monitored by ultrasonography in the patient in whom bone graft and membrane were placed. In 1 patient, the resection area was filled with soft tissue, and ultrasound showed an echogenic area surrounded a hyperechogenic bone border. No internal vascularization was detected. In the other patient, ultrasonography showed a well-contoured anechogenic area with no vascularization, and 3 months after apical surgery, the tooth was extracted. <h3>Discussion/Conclusions</h3> Ultrasound imaging can be a useful tool for the monitoring of apical surgery outcomes without ionizing radiation. Further research is essential with inclusion of more patients.

Management of Large Radicular Lesions Using Decompression: A Case Series and Review of the Literature

The purpose of this study was to report the clinical efficacy of decompression for 3 cases with large periapical lesions and to review technique details. Three cases with large periapical cystic lesions were treated with decompression after root canal treatment. A traditional decompression technique was used for the first case. After aspiration, mucogingival incision, irrigation, and incisional biopsy, a pediatric endotracheal tube was sutured in place and kept for 3 weeks for lesion debridement. An aspiration/irrigation technique was adopted for the second case. An 18-G needle with a syringe was used to aspirate the cystic lesion. Two needles were then inserted into the lesion; copious saline irrigation was delivered from 1 needle and until clear saline was expressed from the other. For the third case, decompression was accomplished with a surgical catheter that was subsequently replaced with a gutta-percha plug after 1 month. None of the 3 cases underwent complete enucleation and root-end surgery. Healed lesions or lesions in healing were observed after 1 to 2 years. Based on the presented cases and published case reports on decompression, a literature review was provided covering indications, technique details, modification, and prognosis of decompression in endodontics. For large periapical cystic lesions, conservative decompression may be used for certain cases before or in lieu of apical surgery. Decompression enables healing of large, persistent periapical lesions after root canal treatment.