Effect of guided tissue regeneration on the success of surgical endodontic treatment of teeth with endodontic-periodontal lesions: A systematic review.

BACKGROUND: Endodontic-periodontal lesions may need surgical approach and the application of guided tissue regeneration (GTR) to be treated by a combined approach. OBJECTIVES: The aim of the present study was to evaluate the effects of GTR on the success (clinical and radiological healing) of teeth with endodontic-periodontal lesions treated by modern surgical endodontic treatment, by means of a systematic review of the literature. METHODS: An exhaustive electronic (Medline, Embase and Scopus searched from inception to August 2020) and manual literature search combined with strict inclusion and exclusion criteria was undertaken to identify any clinical (prospective case series or comparative trials) studies that assessed the added benefit of GTR in modern surgical endodontic treatment of teeth with endodontic-periodontal lesions. The success of the treatment was assessed based on radiographic healing and clinical evaluations. The risk of bias of the identified studies was evaluated using the Cochrane's collaboration RoB 2.0 tool and the Joanna Briggs Institute (JBI) critical appraisal tools. RESULTS: A systematic literature search for eligible reports retrieved three randomized controlled trials (RCTs) and one prospective single arm study with a total of 125 teeth in 125 subjects. One of the RCTs has a low risk of bias, while the other two raised some concerns, using the RoB 2.0 tool. Due to the heterogeneity of the results, it was not possible to perform a comparative meta-analysis and the results are presented in a narrative manner and by calculating pooled outcomes. Pooling together the data from all the included studies, the reported outcome was of complete healing in 58.4% of all cases, of scar tissue formation/incomplete healing in 24% of cases, of uncertain healing in 12.8% of cases, and of failure in 4.8% of all analysed teeth, with a follow-up ranging from 12 to 60 months. DISCUSSION: The scientific evidence about the use of GTR in modern surgical endodontic treatment of endodontic-periodontal lesion is sparse, and the available results are derived from very heterogeneous studies, thus not permitting to clarify which is the most effective treatment option in these cases. CONCLUSIONS: There is an absence of studies comparing GTR versus no GTR. REGISTRATION: The protocol for this review was registered in the PROSPERO database with the registration ID number CRD42022300470.

The Effect of General Anesthesia on the Outcome of Root Canal Treatment in Pediatric Patients-A Retrospective Cohort Study.

This study aimed to evaluate the effect of general anesthesia (GA) on the 1-year outcome of Root Canal Treatment (RCT) performed in pediatric patients and to compare it to the outcome of RCT in pediatric patients without GA. Patients admitted for RCT in permanent dentition in a public hospital, dated 2015 to 2020, age 8-15 with a minimum of one year follow-up period, were included in the study. The sample consisted of 326 teeth from 269 patients treated by a single operator, with a recall rate of 81%. Overall, 124 teeth were treated under GA and 142 teeth were without GA. The mean follow-up time was 31.5 months. Data underwent statistical analysis and the significance threshold was set for p < 0.05. Of the total cases, 90% showed favorable outcomes. A significantly higher favorable outcome was seen in the GA group than in the non-GA group (98% and 85%, respectively, p < 0.001). The outcome was significantly affected by the type and quality of the coronal restoration, degree of root development, and lesion size (p < 0.05). According to the current study, in uncooperative pediatric patients, a more favorable outcome of root canal treatment can be obtained under GA than LA if the procedure is carried out with immediate restoration.

Effectiveness of root resection techniques compared with root canal retreatment or apical surgery for the treatment of apical periodontitis and tooth survival: A systematic review.

BACKGROUND: To manage apical periodontitis in root filled maxillary and mandibular molars, root resection techniques may be employed to avoid the loss of the tooth. OBJECTIVES: The objectives of the study were to systematically analyse the effectiveness of root resection techniques (root resection/crown resection/root amputation) for the management of apical periodontitis with non-surgical root canal retreatment or apical surgery by the evaluation of clinical and patient-related outcomes (PROMS), in human experimental studies and longitudinal studies. METHODS: An electronic literature search in PubMed, MEDLINE via OVID interface, EMBASE and Cochrane Central, supplemented by a manual hand search of the grey literature, was performed up to 25th September 2021. Randomized controlled trials, comparative clinical trials and observational studies reporting on the outcome (tooth survival and patient-reported outcome measures with a minimum follow-up of 1 year) of root resection techniques for treating apical periodontitis were identified. The risk of bias was evaluated using the Newcastle-Ottawa scale. RESULTS: From a total of 2098 reports, 36 were considered for further screening. Three retrospective studies, published between 2018 and 2020, were included in this systematic review. A high heterogeneity in terms of protocols, study design and the reported outcomes were observed. The risk of bias was scored as low to moderate. These three studies consisted of data from 305 resected teeth, from 254 patients, with a follow-up period of 1-16.8 years. Overall, 151 teeth were extracted during the follow-up period. In these studies, root resection treatment was carried out on 42 teeth exclusively for endodontic reasons. One of these studies reported 12 out of 23 teeth lost at follow-up. None of the studies reported on PROMS. DISCUSSION: Although root resection techniques may be used for treating teeth with apical periodontitis, the data are limited. Furthermore, the studies are very heterogeneous and associated with high risk of bias. CONCLUSIONS: Given the current level of available evidence, it is not possible to recommend, or dismiss, root resection techniques for managing apical periodontitis. REGISTRATION: PROSPERO database (CRD42021260306).

The effect of imaging modality on the evaluation of the outcome of endodontic surgery.

OBJECTIVES: The aim of this study was to assess the effect of the imaging modality on the evaluation of the outcome of modern surgical endodontic treatments, based on a systematic review of the literature. METHODS: Strict inclusion criteria were adopted in order to identify studies that assessed the outcome of surgical endodontic treatments. Treatment success rates were pooled. The effect of the imaging modality used for the outcome assessment, and the methodological quality of the studies (based on the risk of bias (ROB)), were evaluated. RESULTS: Nineteen articles were included. The success rates assessed by periapical (PA) radiography were significantly higher than when cases were evaluated by cone beam computed tomography (CBCT; 90 and 35% respectively). This difference was mainly due to a significant proportion of cases that were assessed by CBCT as uncertain healing (48%) compared to only 4% using PA. The success rates ranged between 86 and 92% in low ROB studies, and between 19-100% in high ROB studies. CONCLUSIONS: Outcome assessment based on CBCT may lead to significantly lower estimates of rate of success, and higher rates of uncertain healing, thus presenting a dilemma in the decision-making following surgical endodontic treatment. The success rates of studies with lower methodological quality are more variable than for high quality studies.

Targeting Persistent Biofilm Infections: Reconsidering the Topography of the Infection Site during Model Selection.

The physiology of an organism in the environment reflects its interactions with the diverse physical, chemical, and biological properties of the surface. These principles come into consideration during model selection to study biofilm-host interactions. Biofilms are communities formed by beneficial and pathogenic bacteria, where cells are held together by a structured extracellular matrix. When biofilms are associated with a host, chemical gradients and their origins become highly relevant. Conventional biofilm laboratory models such as multiwall biofilm models and agar plate models poorly mimic these gradients. In contrast, ex vivo models possess the partial capacity to mimic the conditions of tissue-associated biofilm and a biofilm associated with a mineralized surface enriched in inorganic components, such as the human dentin. This review will highlight the progress achieved using these settings for two models of persistent infections: the infection of the lung tissue by Pseudomonas aeruginosa and the infection of the root canal by Enterococcus faecalis. For both models, we conclude that the limitations of the conventional in vitro systems necessitate a complimentary experimentation with clinically relevant ex vivo models during therapeutics development.

The Products of Probiotic Bacteria Effectively Treat Persistent Enterococcus faecalis Biofilms.

Objectives: Enterococcus faecalis is a Gram-positive commensal bacterium that possesses various survival and virulence factors, including the ability to compete with other microorganisms, invade dentinal tubules, and resist nutritional deprivation. E. faecalis is associated with persistent endodontic infections where biofilms formed by this bacterium in the root canal frequently resist dental therapies. Aseptic techniques, such as the inclusion of sodium hypochlorite, are the most commonly used methods to treat E. faecalis infections within the root canal system. In this work, we assess the effectiveness of probiotic strains to prevent the regrowth of E. faecalis biofilm cells treated by sodium hypochlorite irrigation. Methods: First, methods are presented that evaluate the effects of short-term exposure to sodium-hypochlorite on established E. faecalis. Next, we evaluate the effects of the secreted products of probiotic strains on biofilm cells and planktonic cells. Results: Sodium hypochlorite, the treatment conventionally used to decontaminate infected root canal systems, was extremely toxic to planktonic bacteria but did not fully eradicate biofilm cells. Furthermore, low concentrations of sodium hypochlorite induced eDNA dependent biofilms. Strikingly, conditioned medium from the probiotic bacteria Lactobacillus plantarum and Lactobacillus casei was sufficient to fully prevent the regrowth of treated biofilms while showing reduced potency towards planktonic cells. Conclusion: Sodium hypochlorite irrigations may contribute to the persistence of biofilm cells if used at concentrations lower than 3%. Probiotic strains and their products represent a new reservoir of biofilm therapies for E. faecalis infections formed in the root canal system.

Influence of Irrigation Protocol on Peroxide Penetration into Dentinal Tubules Following Internal Bleaching: A Confocal Laser Scanning Microscopy Study.

INTRODUCTION: Discoloration of anterior teeth can result in cosmetic impairment in young children. The walking bleach technique stands out because of its esthetic results with minor side effects. Little information is available regarding the influence of various irrigation solutions on peroxide penetration. The aim of this study is to evaluate the influence of different irrigation protocols on peroxide penetration into dentinal tubules using confocal laser scanning microscopy (CLSM). STUDY DESIGN: Cavity preparations were made in 50 extracted permanent premolars. The teeth went through different irrigation sequences: A. control B. saline C. EDTA, NaOCl D. phosphoric acid E. EDTA, NaOCl, phosphoric acid. Then, mixture of fluorescent dyed sodium perborate paste was placed along the pulp chamber and the coronal access cavity, and was refilled at days 7, 14 and 21. RESULTS: The minimal and maximal penetration depths were 324 and 3045 µm, respectively, with a mean of 1607µm. The stained areas were significantly larger in the buccal and lingual directions (P<0.05). Groups B and C showed significantly larger penetration in weeks 2 and 3 compared to week 1 (P<0.05). Group D and E showed significantly larger penetration compared to groups B and C at all times (P<0.05). CONCLUSION: Bleaching agents penetrate to the extra-radicular region of teeth; however, the level of peroxide penetration is significantly higher when the irrigation sequence consists of phosphoric acid prior the bleaching agent placement.

The Development of Large Radicular Cysts in Endodontically Versus Non-Endodontically Treated Maxillary Teeth.

Background and Objectives: Large radicular cysts of the maxilla present a clinical challenge, as they may cause recurrent infection, severe alveolar bone loss and disruption of the nasal and maxillary sinus floors. The aim of this study was to evaluate the effect of previous root canal treatment on the clinical presentation of large maxillary radicular cysts. Materials and Methods: All cases of radicular cysts treated at the Oral and Maxillofacial Surgery Department of a tertiary public hospital over a period of six years (2012-2018) were evaluated. Histologically confirmed radicular cysts of the maxilla with a maximal dimension of over 15 mm were included. Demographic data of the patients, clinical presentation and radiographic features of the lesions were analyzed. Results: A total of 211 inflammatory cysts were treated in the study period, of these 54 histologically diagnosed radicular cysts in the maxilla were found to have a maximal dimension of over 15 mm. The mean age of patients with large maxillary radicular cysts was 43.3 years, 57.6% of which were male and 42.4% female. The lateral incisor was the most common tooth affected (46.3%). The mean size of the large radicular cysts was 25 mm. Then, 83.8% of the cysts were observed in teeth with previous endodontic treatment. Teeth without endodontic treatment presented clinically with significantly fewer acute symptoms in comparison to teeth with previous endodontic treatment. Conclusions: the vast majority (83.8%) of large maxillary radicular cysts were associated with endodontically treated teeth. Previous endodontic treatment was correlated to increased frequency of clinical symptoms.

Effect of cone beam computed tomography voxel size and dental specialty status on the agreement of observers in the detection and measurement of periapical lesions.

OBJECTIVE: To compare observer agreement between endodontists and oral and maxillofacial radiologists (OMRs) in the detection and measurement of periapical lesions as depicted in cone beam computed tomography (CBCT) with 2 voxel sizes. STUDY DESIGN: In total, 256 CBCT images of maxillary molars were evaluated by 2 endodontists and 2 OMRs. Images were obtained at voxel sizes of 0.2 and 0.4 mm. Observers evaluated 64 endodontically and 64 nonendodontically treated teeth for the presence of periapical lesions using a 5-point confidence scale. Weighted κ values were calculated to determine intra- and interobserver agreement. Intraclass correlation coefficients (ICCs) were calculated to assess intra- and interobserver agreement in width and height measurements of the lesions. RESULTS: Intraobserver agreement ranged from fair to almost perfect, with κ values higher for the OMRs than for the endodontists. Interobserver agreement between endodontists ranged from fair to moderate at the 0.2mm voxel size and was slight at 0.4 mm. Agreement between OMRs was almost perfect at 0.2 mm and ranged from substantial to almost perfect at 0.4 mm. ICC was excellent for all observers in all conditions. CONCLUSIONS: Intra- and interobserver reliability was affected by voxel size and specialty. Correlation for measurements exhibited no variation.

Effects of different irrigation protocols on dentin surfaces as revealed through quantitative 3D surface texture analysis.

The combination of ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) has been advocated as an effective irrigation methodology to remove organic and inorganic matter in root canal therapy. Yet, it was suggested that both solutions might lead to structural changes of the dentinal wall surface, depending on the order of application which might affect sealer mechanical retention. This study aims to evaluate the effect of different irrigating protocols on dentin surface roughness using quantitative 3D surface texture analysis. Data stems from 150 human root dentin sections, divided into five groups, each prepared according to one of the following protocols: Negative control; 17% EDTA; 17% EDTA followed by 5.25% NaOCl; 5.25% NaOCl; and 5.25% NaOCl followed by 17% EDTA. Each dentin sample was examined for its three-dimensional surface texture using a high-resolution confocal disc-scanning measuring system. EDTA 17% and the combined EDTA 17% with NaOCl 5.25% showed considerably higher roughness properties compared to the control and to NaOCl 5.25% alone. However, the irrigation sequence did not affect the dentin roughness properties. Therefore, mechanical retention is probably not dependent upon the selection of irrigation protocol sequence.

Accuracy for diagnosis of periapical cystic lesions.

Clinical differentiation between cystic lesions of endodontic and non-endodontic origin is of importance because correct diagnosis may affect treatment decision making. Most radicular cysts are treated with conservative approaches and, therefore, are not surgically removed. The objective of this study was to determine the accuracy of clinical diagnosis of periapical lesions as compared to the histological findings, and to evaluate various associated factors. All biopsy specimens submitted for histological evaluation from 2002 to 2009 were assessed. Only cases of periapical lesions with complete patient data and clinical diagnosis were included. Sensitivity, specificity and accuracy of the clinical diagnosis were calculated and various patient-related factors were evaluated. Of the 4,908 cases, 183 met inclusion criteria. Histologically, there were 171 lesions of radicular cysts and 12 cases of non-endodontic cysts, including OKC and Incisive Canal Cyst. The diagnostic accuracy for clinical diagnosis for radicular cysts was 91.84% and 91.84% for non-endodontic cysts. There was a high accuracy of clinical differentiation between cystic lesions of endodontic and non-endodontic origin. However, some non-endodontic lesions may be incorrectly diagnosed clinically as lesions of endodontic origin. Histological evaluation may be necessary for the correct diagnosis. Further clinical studies are needed to evaluate clinical examination and histological diagnosis of periapical lesions.

Dental implant placement is a possible risk factor for the development of multiple cracks in non-endodontically treated teeth.

The objective of this study was to evaluate potential risk factors, including the placement of dental implants, for the development of tooth cracks. A series of 212-patients, who were referred for endodontic treatment, were retrospectively screened, of which 72 (34%) patients had been diagnosed with 80-cracked teeth confirmed with an operating microscope. These patients had an average age of 53-years and were equally distributed between genders. Forty-one percent of the cracked teeth were diagnosed after the placement of dental implants, with an average of 3-implants per patient. Seventy percent of the cracks were diagnosed more than 1-year after implant loading. Implant placement was associated with higher odds of having multiple cracks (OR = 9.78, CI:2.320, 41.216)(p < 0.05). The proportion of cracked premolars was relatively high (30%), and most cracked teeth (79%) were vital and with a normal periapical diagnosis (86%). Most cracked teeth (71%) had an amalgam restoration, and teeth restored with amalgam were at a higher risk of having multiple cracks (p < 0.05). Clinicians should be aware of a common profile of endodontic patients with multiple cracks in a non-endodontically treated premolar, restored with an amalgam restoration, which was diagnosed with the cracks more than 1-year after reconstruction utilizing multiple implants.

The Effect of Pulpotomy Base Material on Bacterial Penetration and Proliferation for Pulpotomized Primary Molar Teeth: A Confocal Laser Scanning Microscopy Study.

Introduction: the study aimed to evaluate Enterococcus Faecalis colonization in the pulp chamber in pulpotomized extracted human teeth filled by different pulpotomy base materials (PBMs), using confocal laser scanning microscopy (CLSM). Study design: Cavity preparations were made in 70 extracted primary molars. The pulp chambers were filled using either Intermediate restorative material (IRM), Mineral Trioxide Aggregate (MTA) or Glass ionomer (GI). Twenty-five teeth served controls. The specimens were sterilized, and coronally filled with bacterial suspension for 21 days. The specimens were cut through the furcation area, stained using LIVE/DEAD BacLight Bacterial Viability Kit and evaluated using CLSM. Results: The extent of fluorescent staining was larger in the GI group, compared to the IRM and MTA groups, and larger in the IRM group compared to the MTA group (P<0.05). The minimal and maximal bacterial penetration depths into the dentinal tubules were 55 and 695μm, respectively (mean 310μm), without differences between the materials (GI, IRM, MTA, p>0.05). The ratio of live bacteria to dead bacteria within the evaluated areas was higher in the GI group compared to the IRM and the MTA groups, and higher in the IRM group compared to the MTA group (P<0.05). There were no differences between the mesial, distal and apical parts in any of the evaluations (p>0.05). Conclusions: bacteria colonize the interface between the PBM and dentin and penetrate deeply into the dentinal tubules. The extent and the vitality of the colonized bacteria may be affected by the type of PBM.

Oral cancer-associated fibroblasts predict poor survival: Systematic review and meta-analysis.

OBJECTIVES: To perform systematic review and meta-analysis on correlations between cancer-associated fibroblasts (CAFs) and the risk of death for patients with oral squamous cell carcinoma. SUBJECTS AND METHODS: English literature (1966-2018) was systematically analyzed for studies that immunohistochemically assessed CAF density by alpha-smooth muscle actin and presented 5 year survival rates by Kaplan-Meier plots. Mean age of patients, proportion of male/female patients, and male/female majority (>50% male/female patients) per study were also collected. Significance level for statistical models was p < 0.05. RESULTS: Meta-analysis comprised 11 studies/1,040 patients. Univariate Cox regressions showed that high CAF density was a negative prognostic factor in studies with female and male majority [OR 5.329 (95% CI 3.223-8.811), p < 0.001, and OR 2.208 (95% CI 1.717-2.839), p < 0.001, respectively]. High CAF density with male majority was associated with a more favorable prognosis [OR 0.996 (95% CI 0.979-1.013), p < 0.001]. Multivariate Cox regressions showed that death risk was significantly higher among patients with high CAF density compared to low CAF [OR 2.741 (95% CI 2.220-3.384) p < 0.001]. High mean age and male proportion were significantly protective [OR 0.940 (95% CI 0.925-9.955), p < 0.001, OR 0.125 (95% CI 0.018-0.867), p = 0.035), respectively]. CONCLUSIONS: CAFs increased death risk, male majority, and higher mean age were protective. A clinically validated cutoff for CAF density could serve as a reliable prognostic tool.

Extended Maxillary Sinus Augmentation to the Apical Area of the Neighboring Teeth: Advantages and Limitations.

The extension of sinus floor augmentation beyond the edentulous area, apical to the adjacent teeth, has many therapeutic advantages, but the reliability and safety of the procedure has not been assessed in depth. The present study compares the gain of bone anterior and posterior to the edentulous area and evaluates potential advantages and limitations in the clinical setting. The maximum vertical bone height in the edentulous and extended maxillary sinus augmentation (EMSA) areas and the thickness of the sinus membrane of 65 patients were measured. Those measurements were analyzed using the t test and Pearson correlations. The average vertical bone gain was 11.98 ± 3.53 mm in the edentulous sinus area and 8.60 ± 3.89 mm in the EMSA area (P < .05). Minor perforations of the sinus membrane occurred in 4 patients. There were no postsurgical graft contaminations or periradicular changes during follow-up. EMSA is a reliable and safe procedure with a very low complication rate. This approach is effective and safe for patients who have lost part of their posterior dentition. It enables future implant placement while avoiding the need for sinus reentry and proximal teeth extraction.

Bacterial colonization in the apical part of extracted human teeth following root-end resection and filling: a confocal laser scanning microscopy study.

OBJECTIVES: The purpose of this study was to evaluate Enterococcus faecalis colonization at the apical part of root canals following root-end resection and filling using confocal laser scanning microscopy (CLSM). MATERIALS AND METHODS: The apical 3-mm root-ends of 55 extracted single rooted human teeth were resected, and 3-mm retrograde cavities were prepared and filled using either mineral trioxide aggregate (MTA), intermediate restorative material (IRM), or Biodentine (n = 10 each); 25 teeth served as controls. The roots were placed in an experimental model, sterilized, and coronally filled with E. faecalis bacterial suspension for 21 days. Then, the apical 3-mm segments were cut to get two slabs (coronal and apical). The slabs were stained using LIVE/DEAD BacLight Bacterial Viability Kit and evaluated using CLSM. RESULTS: The fluorescence-stained areas were larger in the bucco-lingual directions compared with the mesio-distal directions (p < 0.05). The mean and maximal depths of bacterial colonization into the dentinal tubules were 755 and 1643 µm, respectively, with no differences between the root-end filling materials (p > 0.05). However, more live bacteria were found in the MTA group in comparison to IRM and Biodentine groups (p < 0.05). CONCLUSIONS: CLSM can be used to histologically demonstrate bacterial root-end colonization following root-end filling. This colonization at the filling-dentine interfaces and deeper into the dentinal tubules may be inhomogeneous, favoring the bucco-lingual aspects of the root. CLINICAL RELEVANCE: Following root-end resection and filling bacterial colonization may lead to inflammatory reactions at the periapical tissues; the viability of the colonized bacteria may be affected by the type of root-end filling material.

Inferior alveolar nerve block for the treatment of teeth presenting with irreversible pulpitis: A systematic review of the literature and meta-analysis.

OBJECTIVE: The objective of the present systematic review was to evaluate, in patients with irreversible pulpitis affecting mandibular posterior teeth, if premedication with nonsteroidal anti-inflammatory drugs can increase the efficacy of inferior alveolar nerve block (IANB) if compared to placebo administration; if one anesthetic agent is more effective than another; if 1.8 mL injection is more effective than 3.6 mL injection to increase the efficacy of IANB; and if supplementary buccal injection is able to increase the efficacy of IANB as compared to a negative control/placebo group. DATA SOURCES: Randomized controlled clinical trials investigating different aspects (technique, premedication with anti-inflammatory drugs, different anesthetic agents) were searched. Success of IANB, as defined in the studies, was considered as the primary outcome. A meta-analysis was performed evaluating relative risks (RRs). Electronic databases (Medline, Embase, Cochrane Central) were searched after preparation of an appropriate search string. After application of selection criteria, a total of 37 studies were included; 19 of them were considered in the meta-analysis. There was evidence of a difference in favor of the use of premedication with anti-inflammatory drugs (RR, 1.80; CI 95%, 1.50-2.14; P < .0001). There was no evidence of a difference between articaine and lidocaine (RR, 1.05; CI 95%, 0.91-1.21; P = .94). With regard to the volume of anesthetic infiltrated, the computed RR was 1.17 (CI, 0.73-1.88) without any significant difference between the use of one or two cartridges (P = .52). The estimated RR for a supplementary buccal infiltration was 1.56 (CI, 1.00-2.42; P = .05). CONCLUSION: The use of premedication with anti-inflammatory drugs before IANB can increase the efficacy of the IANB. The type of anesthetic agent, the volume of anesthetic, and the use of a supplemental buccal infiltration do not seem to affect the efficacy of anesthesia.

Metaplastic changes in the epithelium of radicular cysts: A series of 711 cases.

BACKGROUND: This study was aimed to evaluate the prevalence of metaplastic changes in the epithelium of radicular cysts and to investigate how they relate to the clinical and radiographic characteristics of the cysts, based on a large series of radicular cysts. MATERIAL AND METHODS: Biopsies of cysts of endodontic origin that were examined at the Department of Oral Pathology between 2004 and 2011 have been re-evaluated for this study. Only cases that were re-confirmed with clinical and histological diagnoses of a radicular or residual radicular cyst were included. The included cases were evaluated for the prevalence of metaplastic changes in the form of mucous secreting cells (MSC) or ciliated cells (CC). The relations between the metaplastic changes and the cyst type (radicular or residual radicular), as well as demographic, clinical and radiographic parameters, were statistically evaluated using Fischer and chi-square tests. Significance was set at p<0.05. RESULTS: A total of 711 cysts were included: 677 were radicular cysts (95%) and 34 (5%) were residual radicular cysts. 23 cases had histopathological diagnoses other than radicular or residual radicular cysts and were excluded from the study. MSC were present in 47 (6.6%) cysts. MSC were significantly more common in residual radicular cysts than in radicular cysts [8 (23.5%) and 39 (5.8%), respectively; p<0.001]. MSC-containing cysts were commonly found in asymptomatic patients (10.5%, p<0.001), and usually presented with well-defined radiographic borders (7.2%, p<0.05). CC were present in 34 (4.8%) cysts, with a markedly high prevalence in the maxillary molar sextant (15%, p<0.001). CONCLUSIONS: In the epithelium of radicular and residual radicular cysts the presence of specific metaplastic changes may be related to cyst type, symptomatology, radiographic findings and tooth location. Key words:Radicular cyst, metaplasia, mucous secreting cells, ciliated cells.

Microsurgical re-treatment of an endodontically treated tooth with an apically located incomplete vertical root fracture: a clinical case report.

Although it is challenging, the early diagnosis of a vertical root fracture (VRF) is crucial in order to ensure tooth preservation. The purpose of this clinical case report was to describe reparative surgery performed to treat a tooth affected by an incomplete VRF. A 26 year old male patient was suspected to have a VRF in a maxillary left central incisor, and an exploratory flap was performed in order to confirm the diagnosis. After detecting the fracture, the lesion was surgically treated, the fracture and the infected root-end were removed, and a platelet-rich plasma membrane was used to cover the defect in order to prevent bacterial migration. A 24 month clinical and radiological follow-up examination showed that the tooth was asymptomatic and that the healing process was in progress. The surgical approach described here may be considered an effective treatment for a combined endodontic-periodontal lesion originating from an incomplete VRF and a recurrent periapical lesion.

Endodontic procedures for retreatment of periapical lesions.

BACKGROUND: When primary root canal therapy fails, periapical lesions can be retreated with or without surgery. Root canal retreatment is a non-surgical procedure that involves removal of root canal filling materials from the tooth, followed by cleaning, shaping and obturating of the canals. Root-end resection is a surgical procedure that involves exposure of the periapical lesion through an osteotomy, surgical removal of the lesion, removal of part of the root-end tip, disinfection and, commonly, retrograde sealing or filling of the apical portion of the remaining root canal. This review updates one published in 2008. OBJECTIVES: To assess effects of surgical and non-surgical therapy for retreatment of teeth with apical periodontitis.To assess effects of surgical root-end resection under various conditions, for example, when different materials, devices or techniques are used. SEARCH METHODS: We searched the following electronic databases: the Cochrane Oral Health Trials Register (to 10 February 2016), the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 1), MEDLINE Ovid (1946 to 10 February 2016) and Embase Ovid (1980 to 10 February 2016). We searched the US National Registry of Clinical Trials (ClinicalTrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform for ongoing trials (to 10 February 2016). We placed no restrictions regarding language and publication date. We handsearched the reference lists of the studies retrieved and key journals in the field of endodontics. SELECTION CRITERIA: We included randomised controlled trials (RCTs) involving people with periapical pathosis. Studies could compare surgery versus non-surgical treatment or could compare different types of surgery. Outcome measures were healing of the periapical lesion assessed after one-year follow-up or longer; postoperative pain and discomfort; and adverse effects such as tooth loss, mobility, soft tissue recession, abscess, infection, neurological damage or loss of root sealing material evaluated through radiographs. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data from included studies and assessed their risk of bias. We contacted study authors to obtain missing information. We combined results of trials assessing comparable outcomes using the fixed-effect model, with risk ratios (RRs) for dichotomous outcomes and mean differences (MDs) for continuous outcomes, and 95% confidence intervals (CIs). We used generic inverse variance for split-mouth studies. MAIN RESULTS: We included 20 RCTs. Two trials at high risk of bias assessed surgery versus a non-surgical approach: root-end resection with root-end filling versus root canal retreatment. The other 18 trials evaluated different surgical protocols: cone beam computed tomography (CBCT) versus periapical radiography for preoperative assessment (one study at high risk of bias); antibiotic prophylaxis versus placebo (one study at unclear risk); different magnification devices (loupes, surgical microscope, endoscope) (two studies at high risk); types of incision (papilla base incision, sulcular incision) (one study at high risk and one at unclear risk); ultrasonic devices versus handpiece burs (one study at high risk); types of root-end filling material (glass ionomer cement, amalgam, intermediate restorative material (IRM), mineral trioxide aggregate (MTA), gutta-percha (GP), super-ethoxy benzoic acid (EBA)) (five studies at high risk of bias, one at unclear risk and one at low risk); grafting versus no grafting (three studies at high risk and one at unclear risk); and low energy level laser therapy versus placebo (irradiation without laser activation) versus control (no use of the laser device) (one study at high risk).There was no clear evidence of superiority of the surgical or non-surgical approach for healing at one-year follow-up (RR 1.15, 95% CI 0.97 to 1.35; two RCTs, 126 participants) or at four- or 10-year follow-up (one RCT, 82 to 95 participants), although the evidence is very low quality. More participants in the surgically treated group reported pain in the first week after treatment (RR 3.34, 95% CI 2.05 to 5.43; one RCT, 87 participants; low quality evidence).In terms of surgical protocols, there was some inconclusive evidence that ultrasonic devices for root-end preparation may improve healing one year after retreatment, when compared with the traditional bur (RR 1.14, 95% CI 1.00 to 1.30; one RCT, 290 participants; low quality evidence).There was evidence of better healing when root-ends were filled with MTA than when they were treated by smoothing of orthograde GP root filling, after one-year follow-up (RR 1.60, 95% CI 1.14 to 2.24; one RCT, 46 participants; low quality evidence).There was no evidence that using CBCT rather than radiography for preoperative evaluation was advantageous for healing (RR 1.02, 95% CI 0.70 to 1.47; one RCT, 39 participants; very low quality evidence), nor that any magnification device affected healing more than any other (loupes versus endoscope at one year: RR 1.05, 95% CI 0.92 to 1.20; microscope versus endoscope at two years: RR 1.01, 95% CI 0.89 to 1.15; one RCT, 70 participants, low quality evidence).There was no evidence that antibiotic prophylaxis reduced incidence of postoperative infection (RR 0.49, 95% CI 0.09 to 2.64; one RCT, 250 participants; low quality evidence).There was some evidence that using a papilla base incision (PBI) may be beneficial for preservation of the interdental papilla compared with complete papilla mobilisation (one RCT (split-mouth), 12 participants/24 sites; very low quality evidence). There was no evidence of less pain in the PBI group at day 1 post surgery (one RCT, 38 participants; very low quality evidence).There was evidence that adjunctive use of a gel of plasma rich in growth factors reduced postoperative pain compared with no grafting (measured on visual analogue scale: one day postoperative MD -51.60 mm, 95% CI -63.43 to -39.77; one RCT, 36 participants; low quality evidence).There was no evidence that use of low energy level laser therapy (LLLT) prevented postoperative pain (very low quality evidence). AUTHORS' CONCLUSIONS: Available evidence does not provide clinicians with reliable guidelines for treating periapical lesions. Further research is necessary to understand the effects of surgical versus non-surgical approaches, and to determine which surgical procedures provide the best results for periapical lesion healing and postoperative quality of life. Future studies should use standardised techniques and success criteria, precisely defined outcomes and the participant as the unit of analysis.