Expert consensus on difficulty assessment of endodontic therapy.

Endodontic diseases are a kind of chronic infectious oral disease. Common endodontic treatment concepts are based on the removal of inflamed or necrotic pulp tissue and the replacement by gutta-percha. However, it is very essential for endodontic treatment to debride the root canal system and prevent the root canal system from bacterial reinfection after root canal therapy (RCT). Recent research, encompassing bacterial etiology and advanced imaging techniques, contributes to our understanding of the root canal system's anatomy intricacies and the technique sensitivity of RCT. Success in RCT hinges on factors like patients, infection severity, root canal anatomy, and treatment techniques. Therefore, improving disease management is a key issue to combat endodontic diseases and cure periapical lesions. The clinical difficulty assessment system of RCT is established based on patient conditions, tooth conditions, root canal configuration, and root canal needing retreatment, and emphasizes pre-treatment risk assessment for optimal outcomes. The findings suggest that the presence of risk factors may correlate with the challenge of achieving the high standard required for RCT. These insights contribute not only to improve education but also aid practitioners in treatment planning and referral decision-making within the field of endodontics.

Platelet rich fibrin and MTA in the treatment of teeth with open apices.

BACKGROUND: The present study aimed to evaluate the effectiveness of using platelet-rich fibrin (PRF) as the apical matrix for the placement of MTA in nonsurgical endodontic therapy for teeth with periapical lesions and open apices. METHODS: Twelve teeth from eleven patients with periapical periodontitis and open apices were enrolled in the study. Nonsurgical endodontic therapy was performed with the PRF used as an apical barrier and the MTA manipulated as an apical plug for further thermoplasticized gutta percha in the remaining part of the root canal. Clinical signs and periapical digital radiographs were recorded and analyzed to evaluate the curing progress after periodical follow-ups of 1, 3, and 6 months. The horizontal dimension of the periapical lesion was determined, and the changes in the dimensions were recorded each time. The Friedman test was used for statistical analysis, with P < .05 serving as the threshold for determining statistical significance. RESULTS: All patients had no clinical symptoms after the first month of treatment, with a significant reduction in the periapical lesion after periodical appointments. CONCLUSIONS: PRF is an effective barrier when combined with MTA for the treatment of teeth with periapical periodontitis and open apices.

Outcome of root canal retreatment filled with gutta-percha techniques: A systematic review and meta-analysis.

OBJECTIVE: The present systematic review and meta-analysis aimed to evaluate the success rate of root canal retreatment filled with gutta-percha and the variables related to retreatment success. DATA: The PRISMA guidelines were followed for the present review. The study protocol was registered in the International Prospective Database of Systematic Reviews (PROSPERO CRD42021283134). Risk assessment was performed using the Newcastle-Ottawa scale. Funnel plots were used to detect publication bias and asymmetry was assessed using Egger's tests. SOURCES: PubMed, Scopus, ScienceDirect, Cochrane, and additional sources were searched. STUDY SELECTION: Studies published until 10 December 2022. Clinical studies evaluating the success of root canal retreatment filled with gutta-percha with at least a 1-year follow-up were selected. RESULTS: Ten studies and one unpublished study fulfilled the inclusion criteria for quantitative analysis. The success rate of non-surgical root canal retreatment was 71% (95% CI: 66%-76%) with strict criteria and 87% (79% - 93%) with loose criteria for 1-3 years of follow-up, and 77% (66% - 86%) with strict criteria for a 4-5 years of follow-up. Endodontically retreated teeth with periapical lesions had a lower success rate under strict criteria. The tooth type, dental arch, initial periapical index (PAI) score, and the number of visits also affected the treatment success rate under strict criteria. For the loose criteria, teeth with larger periapical lesions and higher initial PAI scores had a lower success rate. CONCLUSIONS: According to the present systematic review and meta-analysis, non-surgical root canal retreatment results in favourable outcomes. The presence of a periapical radiolucency, periapical lesions >5mm, a higher initial PAI score, multiple-visit retreatments, and mandibular and molar teeth resulted in a lower success rate. CLINICAL SIGNIFICANCE: Non-surgical root canal retreatment filled with gutta-percha techniques is a relatively predictable procedure with a high success rate. Several variables can affect retreatment success, mainly the presence and size of a periapical lesion and the type of tooth.

Postoperative pain of single-visit endodontic treatment with gutta-percha versus MTA filling: a randomized superiority trial.

BACKGROUND: Postoperative pain has remained a challenge for clinicians. This randomized superiority trial compared the levels of postoperative pain following the use of gutta-percha (GP) and sealer or mineral trioxide aggregate (MTA) as root canal filling materials in teeth with asymptomatic apical periodontitis. METHODS: A total of 119 patients were initially evaluated in this two-arm, parallel-group, single-blind, superiority randomized trial. The inclusion criteria were participants aged 18-65 years with single-canal premolars diagnosed with asymptomatic apical periodontitis. The participants were finally divided into two groups using the permuted block randomization method. In the GP group (N = 46), the cleaned and shaped root canals were filled with gutta-percha and AH Plus sealer, while in the MTA group (N = 48), the cleaned and shaped root canals were filled with an MTA apical filling and a coronal gutta-percha and sealer. Patient pain level was measured 6, 12, 24, 48, and 72 h postoperatively using a 10-point visual analog scale (VAS). The data were analyzed by the chi-square, independent t, Friedman, and Mann-Whitney U tests. RESULTS: The mean of VAS scores decreased significantly over time in both groups (P < 0.001). The mean VAS scores were significantly lower in the MTA filling group than in the other group (P < 0.05). Female patients reported higher VAS scores at 6- and 12-hour periods in both groups (P < 0.05). CONCLUSION: MTA as a root canal filling material might be a valuable option for clinicians due to its low postoperative pain. TRIAL REGISTRATION: The trial protocol was registered at the Registry of Clinical Trials (IRCT20191104045331N1).

Intentional replantation for the retreatment of mandibular second molar: a case report.

When the use of root canal retreatment and apical surgery experiences difficulty in treating endodontic diseases, intentional replantation is an optional clinical technique used to retain the tooth. A 28-year-old female complained of chewing discomfort at the mandibular second molar after undergoing root canal treatment 3 month ago. History record and radiographic examination revealed that a C-shaped root canal system was filled with gutta-percha in the mandibular second molar. A radiolucency area existed at the root furcal area with a thin canal wall in the distal and mesial roots. Intentional replantation was used to treat this tooth. The clinical and radiographic results showed that intentional replantation and nano-biomaterial application facilitated infection control, tooth retention, and periodontal tissue regeneration.

Outcome of Nonsurgical Root Canal Retreatment Procedures Obturated with Warm Gutta-percha Techniques: A Longitudinal Clinical Study.

INTRODUCTION: To evaluate the success rate of nonsurgical root canal retreatment at the 2-3-year follow-up and identify the possible prognostic factors. METHODS: Patients who underwent root canal retreatment at a university dental clinic were contacted for clinical and radiographic follow-up. The retreatment outcomes in these cases were based on clinical signs, symptoms, and radiographic criteria. Inter- and intraexaminer concordances were calculated using Cohen's kappa coefficient. The retreatment outcome was dichotomized into success or failure according to strict and loose criteria. The radiographic success criteria consisted of complete resolution or absence of a periapical lesion (strict criteria) or a reduction in the size of an existing periapical lesion at recall (loose criteria). χ2 tests were used to evaluate possible variables associated with retreatment outcomes (age, sex, tooth type, location, contact points, periapical status, quality of previous and final root canal filling, previous and final restoration, number of visits, and complications). RESULTS: Overall, 129 teeth (113 patients) were included in the final evaluation. The success rate was 80.6% under strict criteria and 93% under loose criteria. Molars, teeth with an initially higher periapical index score, and teeth with >5 mm periapical radiolucency had a lower success rate according to the strict criteria model (P < .05). When the loose success criteria were used, teeth with larger (>5 mm) periapical lesions and those that had been perforated during retreatment showed a lower success rate (P < .05). CONCLUSIONS: The present study demonstrated that nonsurgical root canal retreatment is a highly successful procedure after an observation period of 2-3 years. Treatment success is primarily affected by the presence of large periapical lesions.

Clinical outcomes of non-surgical root canal obturations using NeoMTA: A retrospective series of case reports.

NeoMTA is a commercially available tricalcium silicate-based cement intended for contact with pulp and periradicular tissues. The purpose of this study was to retrospectively evaluate the outcomes of non-surgical root canal treatments with NeoMTA obturations. Patients were treated in a private endodontic practice between 2015 and 2018. All cases, including initial treatments and retreatments, were either fully obturated with NeoMTA, or using gutta-percha with NeoMTA as an endodontic sealer. Outcomes were assessed using follow-up examination data with digital periapical radiographs with a minimum of a 1-year recall. Teeth were classified based on the clinical examination as: healed/healing (success), or non-healed (failure). 265 teeth were included with an average follow-up time of 1.3 years. The overall success rate was 91.7%. Only the presence of a pre-operative periapical radiolucency was found to significantly affect success. Comparison of obturation techniques demonstrated no effect on outcomes. NeoMTA is suitable for endodontic obturation.

Effect of QMix as final irrigation protocol on periapical healing after single-visit root canal treatment: A randomised controlled clinical trial.

The aim of this study was to evaluate radiographic periapical repair after endodontic treatment using QMix or NaOCl irrigation in single-rooted teeth with apical periodontitis. In this randomised clinical trial, 60 patients were selected and randomised into two groups (n = 30). After instrumentation of root canals, QMix or NaOCl was used as a final irrigation and the canals obturated with gutta-percha and AH Plus sealer. All the participants were recalled after 12 months and 15 patients were lost to the study so 45 patients were evaluated radiographically according to periapical index (PAI) scores. A significant decrease was seen in PAI scores after 1 year in all patients (p < 0.001). In the QMix and NaOCl group, absence or reduction of radiolucency was observed in 23 of 25 teeth (92%) and 20 of 20 teeth (100%), respectively. There was no significant difference between two groups according to the decrease in PAI score (p = 0.508). Root canal treatments with or without QMix irrigation contributed equally to periapical healing.

Impact of photodynamic therapy on the marginal adaptation of Biodentine used as root-end filling material.

BACKGROUND: The marginal adaptation of root-end filling materials and the effective antibacterial control in a surgical site are crucial for the successful outcome of endodontic surgery. OBJECTIVE: This study aimed to evaluate the effect of retrograde application of photodynamic therapy on the marginal adaptation of Biodentine used as a root-end filling material. METHODS: Twenty single-rooted anterior teeth were selected, instrumented and obturated with gutta-percha and AH Plus. The apical 3 mm of the roots were resected and root-end cavities were prepared with an ultrasonic retro-tip. The teeth were randomly divided into two groups (n = 10). In the first group, photodynamic therapy (PDT) was applied in the retrograde cavity prior to the root-end filling. In the second group retro cavity was filled without PDT. All specimens were obturated with Biodentine and afterwards sectioned longitudinally. The gap width at the material-dentin interface was measured using a scanning electron microscope. The results were statistically analyzed. RESULTS: The produced gap width by Biodentine/PDT was 3.85 µm versus 2.68 µm in the Biodentine control group with significant differences in-between. CONCLUSION: Under the conditions of this study, PDT has a negative effect on the marginal adaptation of Biodentine used as root-end filling material.

Effectiveness of root canal filling materials and techniques for treatment of apical periodontitis: A systematic review.

BACKGROUND: Apical periodontitis (AP) is an inflammatory disease of the apical periodontium as sequelae of pulp death. It is managed by disinfection and filling of the root canal space. OBJECTIVES: The aim of this systematic review was to investigate whether obturation techniques and materials used for root canal filling led to the management of AP. METHODS: A systematic review protocol was written following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) checklist and registered on the international prospective register of systematic reviews (PROSPERO; CRD42021260275) including two populations, interventions, comparisons, outcomes and time (PICOT) for the research questions querying the effectiveness of obturation techniques (PICOT 1) and materials (PICOT 2) for the management of AP. Electronic searches were conducted on PubMed, ScienceDirect, Scopus and Embase search engines. Searches on International Endodontic Journal, Journal of Endodontics, Clinical Oral Investigations, Journal of Dental Research and Journal of Dentistry websites were also conducted, until May 2021. Both primary (tooth survival) and secondary outcomes were evaluated. The risk of bias was assessed by Cochrane RoB2 for the randomized and ROBINS-I for the nonrandomized trials. RESULTS: The search strategy identified 1652 studies, with 1600 excluded on the title and abstract screening, leaving 52 studies for full-text screening. In total, 10 studies met the inclusion criteria. The obturation technique and materials used did not affect the outcome of AP. Vertical compaction resulted in faster resolution of periapical lesions. The oral health-related quality of life of patients treated with lateral condensation exhibited poorer outcomes compared with single matched cone after 6 months of recall. DISCUSSION: The inclusion and exclusion criteria used for this systematic review enabled the capture of all the literature available on the effect of obturation techniques and materials on the outcome of AP. The data were heterogenous, and a number of articles investigating obturation techniques had no information on the materials and techniques used as they looked at the quality of fill. CONCLUSIONS: Included studies did not find any difference between different procedures (PICOT 1) and materials (PICOT 2). The risk of bias was high, thus the findings should be interpreted with caution. REGISTRATION: PROSPERO registration number: CRD42021260275.

Intentional replantation for the retreatment of mandibular second molar: a case report / 华西口腔医学杂志

When the use of root canal retreatment and apical surgery experiences difficulty in treating endodontic diseases, intentional replantation is an optional clinical technique used to retain the tooth. A 28-year-old female complained of chewing discomfort at the mandibular second molar after undergoing root canal treatment 3 month ago. History record and radiographic examination revealed that a C-shaped root canal system was filled with gutta-percha in the mandibular second molar. A radiolucency area existed at the root furcal area with a thin canal wall in the distal and mesial roots. Intentional replantation was used to treat this tooth. The clinical and radiographic results showed that intentional replantation and nano-biomaterial application facilitated infection control, tooth retention, and periodontal tissue regeneration.

USAGE OF CHLORHEXIDINE AS A FINAL IRRIGANT IN ONE-VISIT ROOT CANAL TREATMENT IN COMPARISON WITH CONVENTIONAL TWO-VISIT ROOT CANAL TREATMENT IN MANDIBULAR MOLARS: A RANDOMIZED CLINICAL TRIAL.

OBJECTIVES: The effectiveness of 1-visit root canal treatment (RCT), especially for teeth with large periapical lesions, are still being debated. Although, the use of chlorhexidine (CHX) as a final irrigant have been recommended to provide an optimized approach in 1-visit RCT, there is limited knowledge about the outcome of 1-visit RCT using CHX as the final irrigant. AIM: The aim of this randomized clinical trial was to evaluate the healing of mandibular molar teeth with large periapical lesions after RCT that was completed in 1 visit using 2% CHX as a final irrigant, comparing the results with a conventional 2-visit RCT as a control group. METHODOLOGY: This study is a prospective, parallel-designed, and single-blinded randomized clinical trial. One-hundred asymptomatic mandibular molar teeth with large periapical lesions were randomly assigned to 2 groups. All teeth were instrumented with Reciproc files with 2.5% sodium hypochloride (NaOCl) and 5% ethylenediaminetetraacetic acid (EDTA) as irrigants. In the intervention group, half of the teeth were treated in 1 visit, receiving an additional final rinse with 2% CHX before obturation; the other half of the teeth, however, were treated in 2 visits with calcium hydroxide (CH) dressings, in the control group. All root canals were obturated with Reciproc gutta-percha cones and AH Plus root canal sealer. All patients were recalled and investigated clinically and radiographically for 48 months. Periapical healing was evaluated statistically using the Mann-Whitney U test, followed by the Friedman and the Wilcoxon tests (α = 0.05). RESULTS: During the 48-month follow-up process, 86 teeth (44 in 1-visit and 42 in 2-visit group) were examined. There were no significant differences between the 2 groups regarding the radiographic healing rates (1-visit group 91% and 2-visit group 88%) (P > .05). CONCLUSION: In this study, 1-visit RCT using 2% CHX as final irrigant in asymptomatic mandibular molars with large periapical lesions produced favorable healing results, similar to 2-visit root canal treatment with calcium hydroxide.

Comparison of Fracture Resistance between Single-cone and Warm Vertical Compaction Technique Using Bio-C Sealer® in Mandibular Incisors: An In Vitro Study.

AIM: The aim of the study was to compare the fracture resistance of the single-cone technique with the warm vertical compaction technique (WVCT) in mandibular incisors using Bio-C sealer®, by applying a compressive force using a universal testing machine (UTM) (Instron 5943; Instron, Norwood, Massachusetts, USA). MATERIALS AND METHODS: Twenty-two mandibular incisors were selected and divided into two groups after applying the same shaping protocol. To assess the influence of the wave vertical compaction technique on the fracture resistance, the first group was obturated by a single-cone obturation technique (SCOT) (n = 12), and the second group was obturated with a WVCT (n = 10). Bio-C sealer® (Angelus, Hague Netherlands) was used in the two obturation techniques. Wax-coated roots were put in an acrylic mold and loaded to compressive strength fracture in a mechanical material testing machine (UTM) (Instron 5943; Instron, Norwood, Massachusetts, USA), with Bluehill 3 software (version 3.15.1343) recording the maximum load at fracture. Fracture loads were compared statistically, and data were examined with the Mann-Whitney U test with a level of significance set at p ≤0.05. RESULTS: No statistically significant difference was registered between the SCOT (264.97 ± 83.975 N) and WVCT (313.35 ± 89.149 N) concerning the endodontically treated mandibular incisors' fracture resistance (p = 0.159). CONCLUSION: Warm vertical compaction technique (WVCT) did not affect the fracture resistance of endodontically treated mandibular incisors when compared to SCOT canal preparation. CLINICAL SIGNIFICANCE: General practitioners and endodontists face challenges during root canal treatment such as cracks and root fractures. This article aims to guide experts in choosing between the single-cone and the continuous WVCT aiming for higher long-term quality of root canal filling.

The outcome of endodontic treatment using an enhanced infection protocol in specialist practice.

Objectives This study aims to determine the outcome of primary root canal treatment with specific enhanced infection control protocol. The secondary aim was to compare percentages of successful outcomes in this study with a previous study undertaken by the same operator using both periapical radiograph (PR) and cone beam computed tomography (CBCT).Materials and methods Root canal treatment of 110 teeth in 95 patients carried out by a single operator using an enhanced infection control procedure (disinfection of gutta percha before obturation, changing of gloves after each intraoperative radiograph and also before the start of the root canal obturation). PR and CBCT scans of 94 teeth in 87 patients were assessed 12 months after completion of primary root canal treatment and compared with their respective pre-treatment (diagnostic) PR and CBCT scans. Healing was assessed by a consensus panel consisting of two calibrated examiners. Comparison of the PR and CBCT images for 'healed' and/or 'healing' outcomes was performed using McNemar's test.Results The 'healed' rate (absence of periapical radiolucency) was 89.4% using PR and 78.7% for CBCT (p <0.046). This rate increased to 95.7% for PR and 92.6% for CBCT when the 'healing' group (reduced size of periapical radiolucency) was included (p <0.046).Conclusion The frequent changing of gloves during the course of endodontic treatment and disinfection of gutta percha points before obturation, together with the use of contemporary rotary files, resulted in a high success rate of primary root canal treatment compared to similar clinical studies conducted previously.

Management of teeth with dens invaginatus and apical periodontitis: A case series.

BACKGROUND: Dens invaginatus is a dental anomaly that can predispose the tooth to pulp and periapical pathology. CASE DESCRIPTION: Different endodontists treated 6 maxillary incisors with dens invaginatus associated with apical periodontitis. Cone-beam computed tomography was used to help with diagnosis and treatment planning in most patients. Four patients received diagnoses of Oehlers type II dens invaginatus and the other 2 as type III. In some patients with type II, the invagination had to be perforated to permit access to the apical part of the true root canal. Both the true canal and the invagination (pseudocanal) were treated in all cases using an antimicrobial regimen based on chemomechanical preparation with sodium hypochlorite irrigation and supplementary disinfection approaches. Calcium hydroxide medication was used in all but 1 case. The root canal and invagination were often filled using thermoplasticized gutta-percha techniques, sometimes using an apical plug with a bioceramic material in teeth with large apical openings. All treated patients had favorable clinical and radiographic outcomes. PRACTICAL IMPLICATIONS: Regardless of the complex anatomic variations, common strategic therapeutic approaches were identified that might serve as recommendations for proper management of teeth with dens invaginatus and apical periodontitis. These approaches include cone-beam computed tomographic planning, aggressive disinfection using sodium hypochlorite ultrasonic or sonic activation and calcium hydroxide intracanal medication, and thermoplasticized gutta-percha obturation of both the root canal and invagination.

The effect of two rotary and two reciprocating NiTi systems on postoperative pain after root canal retreatment on single-rooted incisor teeth: A randomized controlled trial.

AIM: This randomized clinical trial aimed to assess the effect of two rotary (ProTaper Retreatment + ProTaper Gold and Hyflex EDM) and two reciprocating (Reciproc Blue and WaveOne Gold) NiTi systems on postoperative pain after root canal retreatment on single-rooted incisor teeth. METHODOLOGY: One hundred and eighty patients scheduled for root canal retreatment were randomly assigned to one of the four groups according to the NiTi system (ProTaper Retreatment + ProTaper Gold, Hyflex EDM, Reciproc Blue or WaveOne Gold) used for the removal of root canal fillings and further canal preparation. The working length was determined to be 1 mm shorter than the '0.0' mark of the apex locator. Root canals were filled with gutta-percha and an epoxy resin-based root canal sealer using a lateral compaction technique. The teeth were restored using a resin composite material. A single operator performed the retreatments in a single visit. The incidence and intensity of postoperative pain were rated on a numeric rating scale by patients 24, 48 and 72 h after retreatment. The number of analgesic tablets (400 mg Ibuprofen) taken by patients was also recorded. Data were analysed using the Mann-Whitney U, Wilcoxon and chi-square tests. RESULTS: For the intensity of postoperative pain, the difference between the four groups was not significantly different (p > .05). No significant difference was found between the groups in terms of analgesic medication intake (p > .05). CONCLUSIONS: The rotary and reciprocating NiTi systems tested in this study were associated with similar intensity of postoperative pain and intake of analgesics following root canal retreatment on single-rooted incisor teeth completed in one visit.

Comparative Evaluation of Root Reinforcement Using MTA-based, Epoxy Resin-based, and Silicone-based Endodontic Sealers in Canals Instrumented with Single-file Rotary System: An In Vitro Study.

AIM: To evaluate root reinforcement by four different sealers, namely, AH Plus, MTA Fillapex, Dia-ProSeal, and GuttaFlow 2, on endodontically treated teeth. MATERIALS AND METHODS: Sixty human mandibular premolars were randomly divided into four groups of 15 teeth each, according to the type of sealer used: Group I AH Plus, Group II MTA Fillapex, Group III Dia-ProSeal, and Group IV GuttaFlow 2. All samples were decoronated to a length of 13 mm from the apex. Root canals were prepared by OneShape, 25/0.06 taper file and obturated with a matching single cone gutta percha (25/0.06) using the above-mentioned sealers. All samples were subjected to load by universal testing machine until a point at which root fractured, which was recorded. RESULTS: Teeth obturated with GuttaFlow 2 showed the maximum fracture resistance followed by AH Plus, Dia-ProSeal, and MTA Fillapex. There was no significant difference in fracture resistance between AH Plus and Dia-ProSeal. CONCLUSION: Teeth obturated with GuttaFlow 2 sealer, which has powdered gutta percha particles, showed the highest fracture resistance. CLINICAL SIGNIFICANCE: According to the results obtained from this study, obturation of roots with GuttaFlow 2 increased the resistance of root canal-filled teeth to vertical root fracture.

Comparación del porcentaje de áreas no obturadas entre la técnica de compactación lateral en frío y la técnica de compactación lateral con ultrasonido / Comparison of the percentage of non-filledventa areas between cold lateral compaction technique and lateral compaction with ultrasonic technique

OBJETIVO: Comparar, en un estudio experimental in vitro, el porcentaje de áreas no obturadas entre la técnica de compactación lateral en frío (TCL) y la técnica de compactación lateral con ultrasonido (TCLU). MATERIALES Y MÉTODOS: El estudio fue realizado en una muestra de 68 dientes humanos extraídos. Se asignaron de manera aleatoria en dos grupos de 34 dientes cada uno. Todos los dientes se cortaron a 16±1 mm de longitud desde el ápice hacia la corona, se instrumentaron con el sistema rotatorio Protaper Next (Dentsply) y se realizó protocolo de irrigación final con NaOCl al 2.5% y EDTA al 17% neutralizados con suero fisiológico entre ellos. El Grupo I se obturó con TCL y el Grupo II con TCLU. En ambos grupos se utilizó Sealapex como cemento. Los dientes fueron seccionados horizontalmente a 2, 4, 6 y 8 mm desde el ápice; cada corte se observó con un microscopio estereoscópico (56X) y se tomaron fotografías. Se calculó el porcentaje de área obturada con gutapercha, cemento y de áreas no obturadas, utilizando el programa ImageJ. El análisis de los resultados se llevó acabo mediante la suma de rangos de Wilcoxon. RESULTADOS: El grupo TCLU presentó un mayor porcentaje de gutapercha en el conducto radicular en comparación con el grupo TCL (94.4% y 87.4% respectivamente), menor porcentaje de áreas no obturadas (1.3% y 4.2%), y menor porcentaje de áreas ocupadas con cemento (3.8% y 7.2%). Las diferencias fueron estadísticamente significativas (P<0.05).CONCLUSIÓN: Los resultados de este estudio muestran que la modificación de la técnica de compactación lateral con ultrasonido descrita en esta investigación presenta resultados in vitro superiores a TCL

AIM: To compare, in an Experimental in vitro study, the percentage of non-filled areas between cold lateral compaction technique (CLT) and lateral compaction with ultrasonic technique (LUT). METHODS: The study was made on in a sample of 68 extracted human teeth. They were randomized into two groups of 34 teeth each. All teeth were cut 16±1 mm from the apex and instrumented with the Protaper Next rotary system (Dentsply) and a final irrigation protocol was performed with NaOCl 2.5% and EDTA 17% neutralized with normal saline solution between them. Group I was filled with CLT and Group II with LUT. In both groups Sealapex was used as a cement. The teeth were sectioned horizontally at 2, 4, 6 and 8 mm from the apex; slices were the viewed through a stereomicroscope (56X) and pictures were taken. The percentage of gutta-percha filled area, percentage of non-filled area and percentage of sealer filled area were calculated for each section using the ImageJ program. Statistical analysis was performed using the Wilcoxon Rank-Sum test. RESULTS: LUT had a higher percentage of gutta-percha in the root canal compared to CLT (94.4% and 87.4% respectively), lower percentage of non-filled area (1.3% and 4.2% respectively), and lower percentage of area occupied by sealer (3.8 % and 7.2% respectively). The differences were statistically significant(P <0.05).CONCLUSION: The results of this study showed that the modification of lateral compaction technique with ultrasonic described in this investigation presents in vitro results superior to CLT

Relación entre la conformación del conducto radicular y las técnicas de obturación tras la instrumentación con TruNatomy, Wave One Gold y ProTaper Gold en conductos curvos simulados de EndoTraining Blocks / Relation between canal shape and filling techniques after instrumentation with TruNatomy, WaveOne Gold, and ProTaper Gold in simulated curved canals from Endo Training Blocks

OBJETIVO: Evaluar en conductos simulados instrumentados con técnicas mecanizadas, la profundidad de penetración de los instrumentos para la obturación con diferentes técnicas y sistemas. MATERIALES Y MÉTODOS: Se emplearon 30 conductos simulados divididos en 3 grupos de 10. Grupo 1. Instrumentado con TruNatomy Prime, Grupo 2. Instrumentado con Wave One Gold Primary y Grupo 3. Instrumentado con ProTaper Gold F2. En cada grupo se realizaron 4 pruebas. 1. Nivel de penetración del atacador manual 9P de 0.6 mm Schilder; 2. Nivel de penetración del atacador Calamus #40 .03; 3. Nivel de penetración de la cánula Calamus 23G; 4. Nivel de penetración del verificador SV20 de GuttaCore para el Grupo 1 y el SV25 para los grupos 2 y 3. Para la evaluación estadística se utilizó análisis de variancia y prueba de Tukey para comparaciones múltiples. Nivel de significación P < 0,05. RESULTADOS: En las pruebas 1,2 y 3, las preparaciones con TruNatomy mostraron una penetración menor de los instrumentos de obturación comparada a las de WaveOne Gold y ProTaper Gold. En la prueba 4, el verificador SV20 fue adecuado con el TruNatomy, en tanto el SV25 lo fue para WaveOne Gold y ProTaper Gold. El análisis estadístico de las pruebas 1,2 y 3 mostró diferencia significativa entre TruNatomy y los otros grupos. En la prueba 4 todos los verificadores penetraron adecuadamente. CONCLUSIONES: 1.- La preparación con TruNatomy Prime dificultó la penetración de los dispositivos necesarios para la obturación con las diferentes técnicas. Para el GuttaCore, el verificador empleado debería ser de un calibre menor al instrumento de prepa-ración. 2.- Los instrumentos WaveOne Gold Primary y ProTaper Gold F2 produjeron una conformación que permitió una penetración mayor de los dispositivos de obturación. Los verificadores GuttaCore de dichos sistemas coincidieron con los instrumentos de preparación

OBJECTIVE: The aim of the study was to evaluate depth of penetration of the instruments used in different obturation techniques and systems in simulated curved canals prepared with three different techniques. MATERIALS AND METHODS: Thirty with simulated curved canals were used and divided into three groups. Group 1 Was instrumented with TruNatomy Prime. Group 2. Was instrumented with WaveOne Gold Primary. Group 3. Was instrumented with ProTaper Gold F2. In each group four tests were carried out. 1. for depth of penetration of manual plugger 9P 0.6 mm Schilder; 2. for depth of penetration of the Calamus Dual plugger #40 .03; Test 3. for depth of penetration of the Calamus Dual cartridge 23G. Test 4. for depth of penetration of the GuttaCore SV20 verifier for group 1 and SV25 verifier for groups 2 and 3. The results were statistically evaluated by the analysis of variance and Tukey multiple comparison test. The level of significance was set at P < 0.05. RESULTS: In tests 1, 2 and 3 canals prepared with TruNatomy showed lower penetration depth than groups prepared with WaveOne Gold Primary and ProTaper Gold. In test 4 verifier SV20 was adequate for TruNatomy, while SV25 was for WaveOne Gold and ProTaper Gold. Statistical analysis of tests 1,2 and 3 showed a significant difference between TruNatomy and the other groups. In test 4, all the verifiers penetrated adequately. CONCLUSIONS:1.- The use of TruNatomy Prime in simulated curved canals limited the penetration of the devices from the different obturation techniques. GuttaCore verifier should be selected one caliber less than the instrument used. 2. WaveOne Gold Primary and ProTaper Gold F2 shaped a canal that allowed deeper penetration of the obturation devices. GuttaCore verifiers employed corresponded with the instruments used

Influence of cervical preflaring and root canal preparation on the fracture resistance of endodontically treated teeth.

BACKGROUND: Evaluate the fracture resistance of endodontically treated teeth after cervical preflaring and root canal preparation and to assess the volume of the root canal and the amount of remaining root dentin before and after cervical preflaring. METHODS: Forty-four mandibular incisors were selected using micro-CT scanning and distributed into 4 groups (n = 11) according to the instrument used for cervical preflaring: control group - no cervical preflaring; Gates Glidden - burs size #2 and #3; WXN - 25.07 Navigator instrument; and Easy - 25.08 ProDesign S instrument. Coronal opening was performed, and the canals were prepared with Wave One Gold Primary and filled with an epoxy-resin based sealer and gutta-percha cones. Micro-CT scans were performed before and after root canal instrumentation. All images were reconstructed and assessed for the thickness of mesial and distal root dentin at 3 mm and 5 mm from the cement -enamel junction and for the volume of cervical portion of the canal after preparation. Fracture resistance test was performed applying compressive loads at a crosshead speed of 0.5 mm/min, applied on the palatal aspect of specimens at 135° along the long axis of the tooth. The data were analyzed using ANOVA and Tukey's test (P = .05). RESULTS: Cervical preflaring and canal preparation reduced the dentin thickness (P < .05) and increased the canal volume (P < .05) in all groups at 3 mm an 5 mm. Cervical preflaring with Gates Gliden burs reduced the fracture resistance of endodontically treated teeth (P < .05). CONCLUSIONS: All instruments reduced the dentin thickness and increased the canal volume in the cervical at 3 mm and 5 mm. Gates Glidden reduced fracture resistance of mandibular incisors submitted to cervical preflaring, whereas NiTi instruments did not. CLINICAL RELEVANCE: Cervical preflaring assumes particular importance previously to the root canal preparation because it minimizes the occurrence of operative accidents, and permits more accurate determination of working length and the apical diameter.