Search

Background : Endodontic treatment aims to thoroughly clean and shape the root canal system to rid it of any infected pulpal tissue or bacteria and to provide a three-dimensional hermetic seal to the root canal system to prevent re-infection. Despite the high rates of success of endodontic treatment, failures do occur, and these may be attributed to the persistence of bacteria in the root canal system, lack of a hermetic seal during obturation, inadequate condensation of gutta-percha, inadequate cleaning and shaping of the canal, coronal leakage or the presence of unidentified accessory canals.For successful endodontic retreatment to occur, all traces of the root filling material (gutta-percha and the sealant) must be removed from the canal walls to enable access to the apical third of the root canal system to be regained. Removal of gutta-percha can be carried out by thermal, laser, chemical, and mechanical techniques or a combination of the above.General Aim : To determine which instruments and solvents Ghanaian dentists use to remove gutta-percha during endodontic retreatment.Methodology : A cross-sectional study was done by giving out a structured questionnaire at a Continuous Professional Development (CPD) event held for dentists. Simple descriptive statistics were used together with Chi-square (χ2) and one-way Analysis of Variance (ANOVA) tests. The chosen level of significance was set at p < 0.05. Unanswered questions were treated as missing values.Results : A total of 64 dental practitioners were surveyed in this study. 32 out of 63(50.8%) respondents performed 2-4 root canal treatments (RCTs) per week, and 49 out of 62(79.0%) performed 0-1% of re-RCTs per week. 59 out of 62(95.2%) practitioners used hand files during root canal treatment. 44 out of 57(77.2 %) practitioners used hand files in combination with solvents, Gates Glidden burs, and barbed broaches during endodontic retreatment. Eucalyptol was the most used solvent during endodontic retreatment, accounting for 31 out of 39(79.5%) positive responses by practitioners.Conclusion : Most Ghanaian dentists use hand files (K-files-54.3%) with solvents (Eucalyptol-79.5%) in the removal of gutta-percha during endodontic retreatment.

Made available in DSpace on 2022-04-29T08:35:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2022-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Introduction: This randomized clinical trial aimed to compare the effectiveness of endodontic retreatment of teeth with posttreatment apical periodontitis (PTAP) performed in 1 visit versus 2 visits on the reduction of cultivable bacteria (colony-forming units [CFUs]), lipopolysaccharides (LPSs), lipoteichoic acid (LTA), and the periapical lesion volume (mm3) after 18 months of follow-up. Methods: Forty patients diagnosed with PTAP were selected and randomly divided into the following 2 groups: 1-visit retreatment and 2-visit retreatment with the placement of calcium hydroxide medication for 14 days. Cone-beam computed tomographic scans were performed at 2 stages: preoperatively and after 18 months of follow-up. Samples were collected before and after root canal procedures. A chromogenic limulus amebocyte lysate assay test was used to quantify endotoxins (EU/mL). LTA levels were measured using the enzyme-linked immunosorbent assay (pg/mL). Culture techniques were used to determine cultivable bacteria by counting the CFU (CFU/mL). The volume of the periapical lesions at the onset of the trial and at the 18-month posttreatment follow-up was obtained by the ITK-SNAP program (Cognitica, Philadelphia, PA). Results: All samples showed baseline values greater than those collected after the retreatment protocol for all investigated parameters. A higher bacterial load and lower LTA level were found in the 2-visit group after the retreatment protocol (P < .05), with no statistical differences between the groups regarding endotoxin levels and periapical lesion volume (mm³) at the 18-month follow-up analyzed by cone-beam computed tomographic imaging (P > .05). Conclusions: Endodontic retreatment in 1 or 2 visits exhibited equally favorable periapical healing at 18 months, with no statistically significant differences between groups. Department of Operative Dentistry Endodontics Division Institute of Science and Technology São Paulo State University São José dos Campos Department of Operative Dentistry Endodontics Division Institute of Science and Technology São Paulo State University São José dos Campos FAPESP: 2014/25789-9 FAPESP: 2017/22676-7 FAPESP: 2018/01703-9

AIM: To evaluate the effect of passive ultrasonic irrigation or XP-Endo Finisher on postoperative pain in patients with underextended filling in previously endodontically treated mandibular first molar teeth requiring endodontic retreatment using visual analog scale (VAS) scale at 6, 12, 24, 48, 72 h, and 7 daytime intervals. METHODS: Seventy-eight patients with mandibular first molars which need endodontic retreatment were randomly allocated into one of three separate groups (n = 26); NaviTip group (control), XP-Endo Finisher group, or Ultra X group. Data were statistically analyzed with a significance level of p ≤ 0.05. RESULTS: XP-Endo Finisher agitation and ultrasonic agitation as a final irrigation protocol showed significantly lower pain values than the control group, but there was no significant difference in pain values between the experimental groups. CONCLUSION: Within the limitation of this study, it can be concluded that agitation techniques used during endodontic retreatment decreased the incidence and intensity of post-operative pain.

The aim of this study was to evaluate the effect of previous root canal treatment on dentinal tubule penetration of calcium silicate-based sealers during endodontic retreatment and to compare 2 different (commonly used and modified) tubule penetration depth measurement techniques.The crowns of mandibular premolar teeth were removed, and root canals were prepared (ProTaper Universal; Dentsply Sirona, York, PA) and obturated using AH Plus (AH; Dentsply DeTrey, Konstanz, Germany), MTA Fillapex (MTAF; Angelus, Londrina, Brazil), and WellRoot ST (WRST; Vericom, Gyeonggi-do, South Korea); 0.1% red Rhod-2 dye (Chemodex, St Gallen, Switzerland) was added to the sealers. After storage for 3 weeks (37°C, 100% humid), the following sealer combination subgroups were created (the sealer used during the primary root canal treatment/the sealer used during the retreatment, n = 8): AH/AH, AH/MTAF, and AH/WRST; MTAF/AH, MTAF/MTAF, and MTAF/WRST; and WRST/AH, WRST/MTAF, and WRST/WRST. Green Fluo-3 dye (0.1%) was added to the sealers during retreatment. Sealer penetration depths were measured at 8 points and averaged, and the ratio of the retreatment sealer to the initial sealer was recorded as the mean tubule penetration depth ratio in the first technique, whereas the percentage of the circumferential penetration area ratios of the retreatment and initial sealers was calculated in the second technique. Statistical analyses were performed using Kolmogorov-Smirnov, Kruskal-Wallis, and Mann-Whitney U tests.The mean penetration depth of AH and MTFA was found to be higher at the coronal third region in the control groups (P .05). Both methods showed a significant difference among the groups at the coronal and median regions (P .05). The AH/WRST, MTAH/AH, MTAF/MTAF, MTAF/WRSTS, and WRST/WRST groups showed deeper tubule penetration (first technique, P = .01). Both techniques showed that the penetration depth of the sealers was the same at the apical region (P .05), whereas a difference was found among the techniques at the coronal and median regions. The sealers used in the previous root canal treatment limited the penetration depth of the sealers used during the retreatment process (P .05). When MTAF was used as the initial sealer, the penetration depth of the second sealer did not change, whereas if WRST was the initial sealer, the penetration depth of the sealers at the median and apical regions is negatively affected during the retreatment process (P .05).Previous root canal treatment affects the penetration depth of calcium silicate-based sealers. The use of AH Plus and MTA Fillapex during the retreatment process showed an advantage. Both measurement techniques showed similar performances at the apical region, whereas the results varied at the coronal and midcoronal regions; therefore, a more stable sealer penetration measurement technique is still necessary.

Aim and Objective: Endodontic retreatment is indicated in the event of a failure of initial treatment of the root canal and of an initial treatment that looks to be correctable with retreatment. This in-vitro study was designed to assess the efficacy of passive ultrasonic irrigation in endodontic retreatment, by employing scanning electron microscopes, on the cleanliness of dentine tubules with and without solvent in curved root channels. Material and method: Sixty human maxillary molar teeth were treated endontically. The protaper rotary instrument was used in root canals in the crown down procedure under copious 3% NaOCl (2 ml) and Glyde irrigation. The saline solution (1 ml) was used for final rinsing. The 10 sample root surfaces of each group were evaluated for SEM pictures. Results: Amongst group I and II here were more open dentinal tubules that were statistically significant (p

Background: Removal of the root canal filling material in the course of the endodontic retreatment is achieved by the use of various instruments and techniques. Purpose: The aim of this article is to systematically analyze published in vitro investigations over a five-year period of time (2018-2022), assessing the efficacy of the XP-Endo Finisher R file as a supplementary approach in orthograde endodontic retreatment. Materials and methods: The literature data was acquired through PubMed - MEDLINE, The Cochrane Library and Science Direct database and hand web search, then the articles were assessed by three independent reviewers. Results: An overall number of eighteen papers out of 108 titles met the eligibility criteria and were finally chosen for quantitative synthesis. Most of the studies affirmed the effectiveness of XP-Endo Finisher R by means of microcomputed tomography. Shaping with the file is not able to guarantee root canal walls free of remnants. Conclusions: XP-Endo Finisher-R is an effective supplementary approach in endodontic retreatment procedures. Nonetheless, it is rarely reported to achieve the complete removal of the root canal filling material. Micro-CT is a reliable, non-invasive analytical tool that can accurately measure the volume and the percentage of the remaining root canal fillings.

Confocal laser scanning microscopy (CLSM) was used to investigate the penetration of endodontic sealers into the dentinal tubules after retreatment using two different obturation techniques.Thirty mandibular premolars were prepared up to instrument F3 (ProTaper Universal, Dentsply) and filled with Endofill using the single cone technique. The canals were retreated using Mtwo instruments. Reobturation was performed with the Bio-C sealer mixed with a fluorophore dye (Fluo-3) using either the lateral condensation technique (group LC) or the single cone technique (group SC) (n = 15). Teeth were sectioned 2, 4, and 6 mm from the apex and analyzed with CLSM to assess the penetration of the sealer into the canal perimeter and the maximum depth of penetration of the sealer into the dentinal tubules. Data were analyzed using ANOVA and the Student-t and Holm-Sidak tests.In the apical segment, the penetrated perimeter was significantly higher in the LC group than in the SC group (p 0.05); no significant difference was found in the middle and cervical segments (p 0.05). In terms of penetration depth, no significant differences were found for any of the segments studied (p 0.05).The LC technique promoted a higher percentage of canal circumference penetrated by the sealer than the SC technique in the apical segment after endodontic retreatment.CLSM demonstrated that the LC technique promoted a higher percentage of canal perimeter penetrated by the Bio-C sealer than the SC technique in the apical segment of mandibular premolars after retreatment.

Aim. To evaluate the antimicrobial efficacy of endodontic retreatment of patients with destructive forms of persistent periodontitis using a combined approach to disinfection of the root canal system and a hyaluronic acid medication.Materials and methods. Group № 1 – endodontic retreatment with root canal disinfection by Hypochloran-3; group № 2 – the same, but for root canal disinfection, first "Hypochloran-3" was applied, and then photodynamic therapy using a 662 nm diode laser and a photosensitizer "ELOFIT®"; group № 3 – in addition to the manipulations carried out in group № 2, of the "Revident" medication was injected twice in the projection of the apical part of the causative tooth. Antibacterial efficacy was assessed according to the results of microbiological studies of biological samples taken before and 2 weeks after endodontic retreatment. The identification of microorganism colonies was carried out by mass spectrometry.Results. In patients with destructive forms of persistent periodontitis, both before and after root canals disinfection, Enterococcus faecalis ranked the first in terms of the frequency of detection in biological samples, Candida albicans the second, and Veillonella parvula the third. At the same time, before the treatment of root canals, the predominance (more than 80%) of polymicrobial associations with their participation was shown. After root canal treatment, the number of obtained microorganism isolates in groups 1-3 significantly decreased: by 60.0%, 74.3%, and 76.0%. Against this background, the share of strict anaerobes and microaerophiles in groups 1-3 decreased: by 60.6%, 81.3%, and 78.1%. The share of facultative anaerobes also significantly decreased by 59.7%, 79.7%, and 83.8%.Conclusions. Endodontic retreatment of patients with destructive forms of chronic periodontitis using combined disinfection of root canals both without and in combination with a hyaluronic acid medication is accompanied by a statistically significant reduction in species diversity, associations, and content of periodontal pathogenic microbiota.

The main goal of orthograde root canal retreatment is to completely remove the root canal content and chemically treat the residual infection. Purpose: The aim of this study was to evaluate the effectiveness of D-Race retreatment files supplemented with XP-Endo Finisher R in the removal of root canal filling material from oval-shaped canals. Methodology: Twelve mandibular incisors initially shaped with XP-Endo Shaper and filled by warm vertical compaction were consistently retreated with D-Race files and XP-Endo Finisher R. Micro-CT images were used to evaluate the quality of the root canal filling and the amount of remaining filling material after the two retreatment procedures. Results: The largest amount of root canal filling was removed at full canal length after using each of the retreatment systems. Significant difference was registered between the accumulated effect of the retreatment with D-Race and XP-Endo Finisher R and the volume of the initial filling material at full canal length (p0.05). The XP-Endo Finisher R file was almost equally efficient in the different portions of the canals but was still most productive apically. Conclusions: The additional application of XP-Endo Finisher R after the D-race retreatment files removed a significant amount of root canal filling. The combined use of the two retreatment systems did not result in completely clean root dentin walls.

Objectives: To evaluate the reliability of sealer penetration measurement methods used with confocal laser scanning microscopy (CLSM) in correlation with the percentage of residual root filling, and to examine the effect of residual root filling on dentine penetrability after endodontic retreatment. Materials & Methods: Root canals of extracted teeth were prepared and obturated using different calcium silicate-based sealers (CSBSs): BioRoot-RCS, MTA-Fillapex, Bio-C, or epoxy resin-based sealer (ERBS) (AH-Plus) and single cone gutta-percha. After 8-week storage, the root filling material was removed, and canals were chemo-mechanically prepared again before obturation using warm vertical compaction and fluorescein labelled ERBS. Control teeth obturated using warm vertical compaction and labelled ERBS were not retreated. Sealer penetration was measured from images obtained by CLSM using 4 methods: maximum and average depth, penetration area, and penetration percentage. Using Spearman’s test, penetration measurements were correlated with the residual filling material obtained from micro-computed tomography. Results: The highest correlation was with the penetration percentage method. Significant differences were found among sealers in the percentage of residual filling material and sealer penetration (pp=0.013) and middle (p=0.016) thirds, respectively. When compared with non-retreated teeth, the penetrability of dentine was not affected by the residual root filling material regardless to the sealer type (p=0.094). Conclusions: Measuring sealer penetration into radicular dentine using the penetration percentage method was found to be the most reliable. Dentine penetrability during retreatment did not seem to be affected by the type of residual root filling material. Clinical Significance: During non-surgical endodontic retreatment, dentine penetrability may not be affected by the residual root filling material after canal preparation regardless to the type of sealer used in the initial treatment.

The access ionization attempt may occur during the coronary period, which may lead to a posterior dental access. The maintenance of the primary tooth is important, especially in cases of permanent tooth agenesis. The aim of this study is to report a clinical case about perforation sealing, endodontic retreatment, and installation of a fixed prosthesis in a lower molar. A patient was selected from the dental clinic of Fapac/Itpac Porto Nacional - TO, asymptomatic, negative sensitivity test and vertical percussion, need for retreatment and perforation in the furcation region. In the first session, anesthesia, access surgery, absolute isolation, irrigation with 2% chlorhexidine gel, identification of the perforation and its conditioning, odontometry, removal of gutta percha with rotary instruments (Logic RT system), drying and insertion of intracanal medication (calcium hydroxide) in root canals and perforation. In the second session (after 15 days), the intracanal medication was removed and the root canals were filled with gutta percha and plasticized technique, and the perforation was sealed with mineral trioxide aggregate (MTA). The clinical case was continued for 2 years, and during the follow-up, asymptomatic, periodontal tissues were clinically and radiographically normal and the dental element performed its masticatory functions satisfactorily. It is possible to conclude with this clinical case that even with a perforation in the furcation region and the need to insert a prosthetic rehabilitation in the dental element, the sealing of the perforation with the aggregate mineral trioxide allowed the maintenance of the dental element.

This systematic review investigated the effectiveness, efficiency and apical extrusion of the debris of two rotary and two reciprocating single-file systems used for the removal of filling material from straight root canals. A literature search was perf

The primary reason for an endodontic treatment failure is the persistence or regrowth of different species of bacteria within the root canal system. The root development and closure of its apex in a permanent tooth occurs till 3 years after the eruption. Treatment of traumatic injury of teeth during the development period of root resulting in open apex poses an endodontic challenge. Various materials are used for induction of apical closure to produce favourable conditions and to conne the root canal lling within the canal space. This paper describes clinical case of retreatment on premolar with improperly treated root canal with open apex. Multiple visit endodontic retreatment of premolar was performed. Disinfection was performed using Intracanal diode laser irrigation activation followed by placing triple antibiotic paste (TAP) as intra-canal dressing. In the second appointment apical plug of Biodentine against a platelet-rich brin (matrix) was condensed. The present case showed successful periapical healing and resolution of symptoms with the use of calcium silicate based cement with platelet-rich brin as an apical barrier matrix. Procedure is followed carefully using recommended protocols.

Failure of the initial root canal treatment is usually manifested by clinical symptoms and/or a residual or newly developed periapical lesion. Retreatment is a common procedure done to treat teeth with failed primary root canal treatment. It can be performed in single visit or multiple visits. Single-visit root canal treatment has become an acceptable treatment protocol especially in primary root canal treatment due to the advantages such as time saving, reduced risk of inter-appointment infection and flare-ups, and lower cost with better patient acceptance.

The present study was conducted to evaluate the presence of aerobic bacteria, anaerobic bacteria, E. faecalis, F. nucleatum, Propionibacteria sp., Actinomyces sp., and their reduction at various stages of endodontic retreatment with the use of conventional protocol (5.25 % Sodium Hypochlorite (NaOCl) as the irrigant along with Calcium Hydroxide (Ca (OH)2) as intracanal medicament and advocated protocol (SmearOFF as the irrigant along with 2% Chlorhexidine (CHX) gel as intracanal medicament).Twenty eight patients fulfilling the eligibility criteria were selected for root canal retreatment and randomly allocated into two groups. Group 1: Final irrigant as SmearOFF+Chlorhexidine 2% gelas intracanal medicament (n=14). Group 2: Final irrigant as 5.25% NaOCl+Ca(OH)2 as intracanal medicament (n=14). With aseptic environment, access opening was performed followed by Gutta Percha (GP) removal and sample S1 was collected for bacterial analysis. The biomechanical preparation was done by using Reciproc system with additional finishing with XP-Endo Finisher R. Sample S2 was then collected for bacterial analysis after the final irrigation protocol in the respective groups. Intracanal medicaments were placed for one week and sample S3 was collected. All the samples were subjected to qualitative analysis using PCR and quantification was done by Colony Forming Unit (CFU) analysis.Aerobic [28/28], Anaerobic [28/28], Propionibacterium sp. [20/28] and F. nucleatum [24/28] were the most frequently isolated in S1 sample followed by Actinomyces sp. [16/28] and E. faecalis sp. [19/28]. Chemico-mechanical preparation followed by irrigation (S2 sample) resulted in significant reduction of all types of bacteria in both groups. Group-1 (SmearOFF as the final irrigant) had significantly superior efficacy against aerobic bacteria, E. faecalis and F. nucleatum (P0.05) as compared to Group-2 (NaOCl). After medicament placement, significant differences between the groups were noted only for the E. Faecalis group. For the S3 samples, the mean bacterial reduction was significant in Aerobic and F. nucleatum in S3 samples for Group 1 and Group 2.Chemico-mechanical preparation followed by irrigation resulted in significant reduction in bacterial load irrespective of the final irrigant. SmearOFF was significantly better than NaOCl in minimizing bacterial load of E. faecalis and F. nucleatum. 2% Chlorhexidine gel has superior antimicrobial efficacy against E. faecalis and may be recommended in secondary endodontic treatment.

Introduction: In the endodontic treatment and retreatment scenario, the primary objective is to eliminate necrotic tissue and infectious bacteria, especially cleaning and shaping. Endodontic retraction is a procedure performed on a tooth that has received a previous attempt at a definitive treatment that has resulted in a condition that requires further endodontic treatment to achieve a successful outcome. The main cause of treatment failure is insufficient cleaning and inadequate filling. Objective: The present study carried out a concise systematic review to evaluate the main findings of clinical studies on endodontic retreatments, showing the main techniques, efficacy, and safety. Methods: The rules of the Systematic Review-PRISMA Platform. The research was carried out from December 2021 to March 2022 and developed based on Scopus, PubMed, Science Direct, Scielo, and Google Scholar. The quality of the studies was based on the GRADE instrument and the risk of bias was analyzed according to the Cochrane instrument. Results: A total of 124 articles were found. A total of 74 articles were evaluated in full and 17 were included and evaluated in the present study. Studies have demonstrated the effectiveness of rotational systems in endodontic retreatment but never producing completely obturator-free root canals. Reciproc instruments were associated with significantly higher cyclic fatigue strength than WaveOne instruments. The persistent infection microbiota is polymicrobial with a predominance of E. faecalis and P. gingivalis in all stages of endodontic retreatment, regardless of the method used for microbial identification. A higher bacterial load and lower lipoteichoic acid level were found in the 2-visit group after the retreatment protocol. Postoperative pain was significantly reduced at 48 and 72 hours after the application of nano-silver and nano-calcium hydroxide alone. Conclusion: The results of clinical trials showed that the root canal instrumentation system with rotary files maintains the quality of the root preparation and reduces the number of files needed to obtain a canal, which would consequently reduce the operative time and also considerably reduce the risk of torsion fracture within the root canal, allowing successful endodontic retreatment. Also, a condition for successful endodontic retreatment is the adequate cleaning of the root canals, therefore, special attention must be given to the technique used to remove the filling material.

Mandibular canines usually have one root with one root canal. However, variations may occur. The present study reports two cases of successful retreatment of two mandibular canines with two roots and two root canals, a rarer configuration. In both cases reported, the unsuccessful treatment in the primary endodontic intervention was due to overlooking the lingual root canals, which were identified when periapical radiographs were taken at a mesial angle. Because canals missed during endodontic therapy may lead to periapical periodontitis, it is important to take radiographs from different angles, analyze the pulp chamber floor, and consider the variations in root canal morphologies. After performing the access cavity and observing an isthmus in both cases, the lingual root canals were located and instrumented. Calcium hydroxide dressing was used between appointments, and the root canals were filled with different sealers in each case (epoxy resin-based and bioceramic sealers). The follow-up X-rays taken 18 months later in the first case and 5 months later in the second case suggested normality of the periapical tissues. It is essential to use strategies that enable reaching the whole complexity of the root canal system during the canal cleaning, shaping, disinfection, and filling procedures in order to control the infection and achieve a successful endodontic treatment outcome.

Submitted by Larissa Pereira Nunes (larissa.p.nunes@unesp.br) on 2022-03-03T12:50:55Z No. of bitstreams: 1 DISSERTAÇÃO LARISSA 01-03.pdf: 777669 bytes, checksum: 0a15b12a8ef68e2174e51da2969b8c04 (MD5) Approved for entry into archive by Claudio Hideo Matsumoto null (claudio@foa.unesp.br) on 2022-03-03T17:07:43Z (GMT) No. of bitstreams: 1 nunes_lp_ me_araca_int.pdf: 777669 bytes, checksum: 0a15b12a8ef68e2174e51da2969b8c04 (MD5) Made available in DSpace on 2022-03-03T17:07:43Z (GMT). No. of bitstreams: 1 nunes_lp_ me_araca_int.pdf: 777669 bytes, checksum: 0a15b12a8ef68e2174e51da2969b8c04 (MD5) Previous issue date: 2022-02-11 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Este trabalho objetivou realizar duas revisões sistemáticas com as seguintes propostas: 1) Avaliar se a fototerapia com laser resultaria em menor dor pós-operatória (PP) em pacientes submetidos a reintervenção endodôntica; e 2) Avaliar se o uso da terapia fotodinâmica antimicrobiana (aPDT) seria eficaz na desinfecção de canais radiculares em casos de reintervenção endodôntica. As Revisões Sistemáticas foram registradas no PROSPERO (CRD42021243500 e CRD42021260013, respectivamente) e seguiram as diretrizes dos Itens de Relatório Preferenciais para Revisões Sistemáticas e Meta-análise (PRISMA). As buscas foram realizadas nas bases de dados eletrônicas PubMeb, Scopus, Web of Science, Embase, Web of Science, Clinical Trials e Cochrane Library e nos bancos de dados da literatura cinza. A qualidade metodológica e o risco de viés foram avaliados pela ferramenta Cochrane Risk of Bias para ensaios clínicos randomizados (RCT) e pelo qualificador NewcastleOttawa (NOS) para estudos não RCT (prospectivos). A análise da qualidade de evidência foi realizada com base na abordagem GRADE. A meta-análise foi realizada com o R software Meta package, utilizando um intervalo de confiança (IC) de 95%. Quanto aos resultados do Artigo 1: Cinco artigos foram incluídos para análise. Os estudos foram classificados como "baixo" risco de viés. Dos cinco estudos clínicos, quatro estudos mostraram uma diminuição significativa da PP após a reintervenção endodôntica nos grupos de fototerapia a laser quando comparados ao grupo controle, principalmente nos primeiros dias após a intervenção. A certeza de evidência foi classificada como baixa. Devido à alta heterogeneidade clínica entre os estudos, não foi possível realizar qualquer meta-análise. Apesar das limitações desta revisão sistemática, a fototerapia se mostrou uma alternativa promissora na redução e controle da PP na reintervenção endodôntica não cirúrgica. Nos resultados do Artigo 2, dez estudos atenderam aos critérios de elegibilidade e foram incluídos, sendo 8 utilizados na síntese quantitativa. A meta-análise mostrou que todos os dados dos estudos apresentaram diferença significativa antes e depois da terapia fotodinâmica antimicrobiana na redução da carga microbiana em infecções endondônticas secundárias (OR 0,15 [0,07; 0,32], p

Journal of The Dental Association of Thailand, 72, 3, 459-466

Non-surgical endodontic retreatment is a reliable conservative option for managing post-treatment apical periodontitis. However, effective microbial control, based on the maximization of filling removal and disinfection protocols, is not yet predictable. Traditional gutta-percha solvents, which are indistinctively used for both the core and sealer filling materials, became obsolete due to unprecedented advances in endodontic technology. Nonetheless, microtomography, scanning electronic microscopy findings, and histobacteriological analysis tend to confirm the persistence of filling materials and the lack of association between root canal enlargement and superior disinfection. There is a controversy regarding the most suitable clinical protocols surrounding the shaping procedures and the supplementary disinfection steps. Based on the literature and the previous work of the team, the authors aimed to summarize the current knowledge regarding specific solvent formulations that target filling materials. Additionally, the advantage of an additional irrigation step to optimize disinfection was highlighted. This adjunctive procedure serves a dual role in the dissolution of filling materials, and in conferring an antibiofilm effect. Further research is needed to understand the novel contribution of these strategies upon clinical practice outcomes.

The objectives of this study were to compare the effects of various acid solutions combined with ultrasonics as an aid to remove mineral trioxide aggregate (MTA)-based root canal filling and to assess their effect on the surface topography and microhardness of root canal dentin. Materials and Method: Fifty human permanent single rooted and single canaled freshly extracted teeth were decoronated and sectioned apically to prepare the middle third of root sections of 5 mm length. The canals were prepared in a step-back manner. OrthoMTA was packed throughout the prepared canals. These root sections were incubated for one week and subsequently randomly allocated to five groups (n = 10) according to the OrthoMTA removal method: No treatment (NT); 5% glycolic acid + ultrasonics (5% GA+U); 10% glycolic acid + ultrasonics (10% GA+U); 10% citric acid + ultrasonics (10% CA+U); Distilled water + ultrasonics (DW+U). A 1 mm deep well was created within the coronal end of the set OrthoMTA. Wells were filled with each respective test solution and left for 5 min. Thereafter, further removal of OrthoMTA used a specific ultrasonic tip. Finally, the canals were flushed using 1 mL of the respective test solutions and activated with a Controlled Memory ultrasonic tip for two cycles of 20 s each followed by flushing with 1 mL of distilled water and paper point drying of the canals. Then, specimens were longitudinally split into two halves and examined under a scanning electron microscope (1000×) to assess the residual OrthoMTA and surface topography of root canal dentin. The Vickers surface microhardness of treated radicular dentin was measured using the HMV-2 microhardness tester. Result: Data were analysed using one-way ANOVA followed by Tukey’s post hoc test. Significant differences for residual OrthoMTA were observed between (10% GA+U) with (5% GA+U), (10% CA+U), (DW+U) and (NT) (p value < 0.01). In the context of microhardness, (5% GA+U) and (10% GA+U) showed statistically significant difference compared to (NT), (10% CA+U) and (DW+U) (p value < 0.01). Conclusion: 10% GA+U was superior to other tested groups in removing OrthoMTA, but it substantially reduced dentin microhardness.

O presente estudo retrospectivo analisou os fatores que contribuem para a incid?ncia de retratamentos endod?nticos de dentes tratados no Curso de Gradua??o em Odontologia e de Especializa??o em Endodontia da Pontif?cia Universidade Cat?lica do Rio Grande do Sul (PUCRS) no per?odo de mar?o de 2015 a dezembro de 2019. A coleta dos dados foi realizada com base nos registros dos prontu?rios dos pacientes atendidos na Unidade de Atendimento Odontol?gico da PUCRS. Foram coletados dados sociodemogr?ficos e de sa?de geral dos pacientes. Al?m de dados espec?ficos do tratamento e retratamento endod?ntico: n?mero do dente, data de in?cio e de t?rmino do tratamento, disciplina na qual o tratamento foi realizado, intercorr?ncias durante e ap?s o t?rmino do tratamento, material utilizado para selamento provis?rio entre consultas e ao final do tratamento, n?mero de sess?es at? o t?rmino do tratamento, cimento endod?ntico, indica??o de encaminhamento para tratamento restaurador, identifica??o de atendimentos de urg?ncia durante o per?odo de encaminhamento, identifica??o da realiza??o do tratamento restaurador final (tipo, data da finaliza??o e disciplina), raz?o da indica??o do retratamento endod?ntico, indica??o de exodontia. Os resultados preliminares foram apresentados atrav?s de estat?stica descritiva. Foram identificados 401 dentes retratados endodonticamente no per?odo, sendo 35 retratamentos endod?nticos de dentes tratados endodonticamente na PUCRS, atingindo a incid?ncia de 8,7%. Dos 33 pacientes (35 dentes) inclu?dos na amostra, 21 (64%) eram mulheres e 12 (36%) eram homens com uma m?dia de idade de 57,1 anos (DP = 13,0). 87,9% (n = 31) dos pacientes relataram ter algum comprometimento sist?mico. Dentes anteriores e pr?-molares foram os mais frequentes (n = 30; 85,8%). Os principais fatores para indica??o de retratamento endod?ntico foram: perda do selamento provis?rio em 11 dentes (31,4%), 5 dentes (14,3%) foram diagnosticados com periodontite apical e 3 dentes (8,6%) tiveram o retratamento indicado por quest?es t?cnicas. Dos 35 dentes indicados para retratamento, 5 dentes (14,3%) haviam recebido restaura??o final. Ap?s o retratamento, 23 (74,2%) dentes receberam a restaura??o final. Dos 31 retratamentos endod?nticos realizados, 6 dentes (19,3%) foram extra?dos, desses, 4 (12,9%) permaneciam com selamento provis?rio desde a conclus?o do retratamento. Os resultados preliminares sugerem que a incid?ncia de retratamentos endod?nticos parece estar associada, muito mais, a falhas de fluxo do atendimento que levaram ao insucesso do que, necessariamente, ao insucesso t?cnico do tratamento prim?rio em si. The present retrospective study analyzed the factors that contribute to the incidence of endodontic retreatments of teeth treated in the Dental School and Specialization Course in Endodontics at the Pontifical Catholic University of Rio Grande do Sul (PUCRS) from March 2015 to December 2019. Data collection was performed based on the medical records of patients treated at the PUCRS Dental Care Unit. Sociodemographic and general health data from the patients were collected. In addition to specific data on endodontic treatment and retreatment: tooth number, beginning and ending of the treatment, discipline in which the treatment was performed, complications during and after the end of treatment, type of temporary sealing between appointments and at the end of the treatment, number of sessions until the end of treatment, endodontic sealer, referral for restorative treatment, identification of urgent care during the referral period, completion of the final restorative treatment (type, date and discipline), reasons for the indication of endodontic retreatment, indication of extraction. Preliminary results were presented using descriptive statistics. A total of 401 endodontically retreated teeth were identified in the period, with 35 endodontic retreatments of endodontically treated teeth at PUCRS, reaching an incidence of 8.7%. Of the 33 patients (35 teeth) included in the sample, 21 (64%) were female and 12 (36%) were male with a mean age of 57.1 years (SD = 13.0). 87.9% (n = 31) of patients reported having some systemic condition. Anterior teeth and premolars were more frequently treated (n = 30, 85.8%). The main factors for endodontic retreatment indication were loss of temporary sealing in 11 teeth (31.4%), 5 teeth (14.3%) were diagnosed with apical periodontitis and 3 teeth (8.6%) had the retreatment recommended because of technical reasons. Of the 35 teeth indicated for retreatment, 5 teeth (14.3%) had received the final restoration after the primary treatment. After retreatment, 23 (74.2%) received the final restoration. Of the 31 endodontic retreatments performed, 6 teeth (19.3%) were extracted, of which 4 (12.9%) remained with the temporary restoration since the conclusion of the retreatment. Preliminary results suggest that the incidence of endodontic retreatments seem to be associated, much more, with issues of patient flow that led to failure than, necessarily, to the failure of the primary endodontic treatment itself. Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES

Aim: Creating apical plug formation with mineral trioxide aggregate (MTA) is beneficial for teeth that have lost their apical barrier due to infection. This case report aims to present the retreatment of a left mandibular first premolar tooth with external root resorption of a patient with hamamy syndrome.Summary: A 21-year-old male patient suffering from hamamy syndrome was referred complaining of spontaneous pain and swelling in his mandibular left first premolar. The tooth was diagnosed with an acute apical abscess. It was previously retreated by an endodontic specialist in our department. Apical surgery was not applicable because of the tooth structure and second endodontic retreatment was performed., Amaç: Enfeksiyon nedeniyle apikal bariyerini kaybetmiş dişler için mineral trioksit agregat ile apikal tıkaç oluşturmak faydalıdır. Bu vaka raporu, Hamamy Sendromlu bir hastada eksternal kök rezorpsiyonu bulunan sol mandibular birinci premolar dişin endodontik yeniden tedavisini sunmayı amaçlamaktadır.Özet: 21 yaşında hamamy sendromu olan erkek hasta, mandibula sol birinci premolarında spontan ağrı ve şişlik şikayeti ile sevk edildi. Dişe akut apikal apse teşhisi kondu. İlgili diş daha önce bölümümüzdeki bir endodonti uzmanı tarafından yenilenmişti. Diş yapısı nedeniyle apikal cerrahi uygulanamadı. Hastaya endodontik yeniden tedavi planlandı.

O tratamento endodôntico tem como objetivo a limpeza adequada e modelagem do espaço do canal radicular. Múltiplos fatores têm sido associados ao insucesso do tratamento endodôntico não cirúrgico. Perante o insucesso, o retratamento endodôntico não cirúrgico deve ser considerado como primeira abordagem de tratamento. A introdução das limas de níquel-titânio (NiTi) no final da década de 1980 levou a uma revolução na endodontia. Os instrumentos de NiTi têm muitas vantagens, como a alta flexibilidade, a superelasticidade, tempo de preparação mais curtos e melhor capacidade de centralização do canal. Os sistemas NiTi começaram a ser usados para reduzir as falhas decorrentes do procedimento endodôntico, podendo ser usados em movimentos rotatórios ou movimentos reciprocantes. O objetivo desta revisão sistemática é comparar, através da literatura científica, a lima Reciproc Blue (RCB) vs lima XP-Endo Shaper (XPS), permitindo avaliar a resistência à fadiga cíclica, capacidade de centralização e remoção do material obturador. Foi realizada uma pesquisa bibliográfica na base de dados PubMed, utilizando as palavras-chave “Reciproc blue”, “XP-Endo shaper”, “Centering ability”, “Cyclic fatigue”, “Endodontic retreatment”. A pesquisa teve como espaço temporal o período de 5 anos. Foram obtidos 94 artigos, os quais passaram por uma fase de seleção e que após a aplicação dos critérios de exclusão e inclusão foram restritos a 26. Os artigos analisados demonstraram a importância do tratamento térmico e de outras características das ligas na rigidez e elasticidade dos instrumentos endodônticos RCB e XPS em relação a outros sistemas. A lima XPS apresentou melhores resultados quando comparada com os outros sistemas rivais. O sistema XPS, apresentou melhor centralização do preparo e remoção do material obturador quando comparado ao sistema RCB. Endodontic treatment aims at a proper cleaning and shaping of the root canal space. Multiple factors have been associated with non-surgical endodontic treatment failure. Facing failure, non-surgical endodontic retreatment should be considered as the first treatment approach. The introduction of nickel-titanium (NiTi) files files in the late 1980s led to a revolution in endodontics. NiTi instruments have many advantages such as high flexibility, superelasticity, shorter setup time and better channel centering capability. NiTi systems began to be used to reduce failures resulting from the endodontic procedure, being able to use rotary movements or reciprocating movements. The objective of this systematic review is to compare, through scientific literature, the Reciproc Blue (RCB) file vs the XP-endo Shaper (XPS) file, allowing to evaluate the resistance to cyclic fatigue, capacity of centering and removal of the filling material. A bibliographic search was carried out in the PubMed database, using the keywords “Reciproc blue”, “XP-endo shaper”, Centering ability”, “cyclic fatigue”, “endodontic retreatment”. The research had a time period of 5 years. A total of 94 articles were obtained, which went through a selection phase and which, after applying the exclusion and inclusion criteria, were restricted to 26. The articles analyzed demonstrated the importance of heat treatment and other characteristics of alloys in the stiffness and elasticity of endodontic instruments. RCB and XPS compared to other systems. The XPS file performed better when compared to other rival systems. The XPS system showed better centralization of the preparation and removal of filling material when compared to the RCB system.

Background: Retreatment procedures are carried out where root canal treatment of teeth fails. There are a variety of methods used to remove gutta-percha from the root canal such as hand files, rotary files, and ultrasonic instruments. Aim: An in-vitro comparison of efficiency of gutta percha removal in retreatment using protaper retreatment files, race instruments and reciproc R. Settings and Design: The present study is an in-vitro comparative study. Methods and Material: Seventy-five extracted non carious human premolar single rooted teeth were used in this study. Root Canal Treatment of these teeth was performed and obturation carried out with Gutta Percha and AH plus sealer. The specimens were randomly divided into 3 experimental groups. In these groups protaper retreatment files, D-Race file system and the Reciproc file system were used, respectively. Residual obturating material on canal walls was evaluated through i-CAT tomography (CBCT). Statistical analysis used: One-way ANOVA test was used to find out the difference in efficacy of gutta percha removal between the groups. Results: There were significant differences between the efficacy of the file systems across the coronal, middle and apical third. The highest percentage of filling material remaining was in Protaper followed by D-Race file and minimum in the Reciproc file. Conclusions: The Reciproc reciprocating system was most effective followed by D – Race file and ProTaper Universal Rotary Retreatment system was least effective for the removal of gutta-percha in retreatment procedures.

This study evaluated the Reciproc R25 and Pro-R 25 instruments in unused condition, after one and a second use in endodontic retreatment employing a noncontact 3D light interferometer profiler, scanning electron microscopy (SEM) and cyclic fatigue tests. Twenty single-root teeth were instrumented with Reciproc R25 and filled with gutta-percha and sealer. A 3D profiler with a 20x objective using the Mx™ software was used to evaluate the cutting blade surfaces of Reciproc R25 and Pro-R 25 (n=5 per group) in unused condition, after the first and second uses in retreatment procedures. After retreatment, SEM was used to evaluate the topographic features of the used instruments. Cyclic fatigue tests were performed to compare new to used instruments. One-way ANOVA followed by Tukey test was used to compare the tested instruments before and after the first and second uses. Student t-test was used to compare the different instruments and for cyclic fatigue evaluation. No significant differences were observed in the cutting blade surfaces of Reciproc and Pro-R before and after one and two uses (p>0.05). Reciproc without use showed higher Sa and Sq when compared to Pro-R without use (p0.05). New and unused Reciproc showed longer time to fracture than Pro-R instruments (p

The purpose of this in vitro study was to evaluate the shaping ability of reciprocating and continuous rotary systems after root canal retreatment. After preparation and root canal filling, mesial canals of 54 mandibular molars were distributed into 3 groups (n=18), according to the filling material removal and re-instrumentation protocols: WOG group - WaveOne Gold system; PTN group - ProTaper Next system; and PTU group - ProTaper Universal system. Cone-beam computed tomographic (CBCT) images acquisition of the mesial root canals was performed at different moments: (1) before instrumentation (unprepared root canals), (2) after preparation and filling, (3) after filling material removal and (4) re-instrumentation. The apical transportation (AT), centering ability (CA) and change in root canal diameter were assessed by CBCT analysis. The remaining filling material quantification was performed by radiographic examination. The statistical analyses were performed using the 3-way ANOVA, Tukey-Kramer, Kruskal-Wallis and Dunn multiple Comparison tests (p0.05). The tested systems provided minimal alteration in root canal morphology at the apical portion after root canal retreatment. However, WOG promoted greater change in root canal diameter. Resumo O objetivo deste estudo in vitro foi avaliar a capacidade de modelagem de sistemas rotatórios e reciprocantes após o retratamento do canal radicular. Após o preparo e obturação do canal radicular, os canais mesiais de 54 molares inferiores foram distribuídos em 3 grupos, de acordo com os protocolos de remoção do material obturador e re-instrumentação: (n=18): grupo WOG - sistema WaveOne Gold; Grupo PTN - sistema ProTaper Next; e grupo PTU - sistema ProTaper Universal. A análise das imagens de tomografia computadorizada de feixe cônico foi realizada em diferentes momentos: (1) antes da instrumentação (canais radiculares não preparados), (2) após o preparo e obturação, (3) após a remoção do material obturador e (4) re-instrumentação. O transporte apical (TA), a capacidade de centralização (CC) e a mudança no diâmetro do canal radicular foram avaliados por análise tomográfica. A quantificação do restante do material obturador foi realizada por exame radiográfico. As análises estatísticas foram realizadas utilizando os testes de ANOVA de 3 fatores, Tukey-Kramer, Kruskal-Wallis e Comparações Múltiplas de Dunn (p0,05). Os sistemas testados proporcionaram alteração mínima na morfologia do canal radicular na porção apical após o retratamento do canal radicular. No entanto, WOG promoveu maior alteração no diâmetro do canal radicular.

Objectives: The aim of this study was to evaluate the retreatment duration and efficacy of eucalyptol and tea tree oil in engine driven and manual retreatment of epoxy resin based endodontic filling in extracted human teeth. Material and methods: Sixty human single rooted teeth were randomly divided into two groups. The first group was prepared using hand files, and the second one using Reciproc system. Root canals were filled with guttapercha points and AH Plus sealer. Retreatment was performed using K-reamers and Hedström files for the first group, and Reciproc instruments for the second group. Each group was divided into two subgroups (n=15) according to the retreatment solvent used (eucalyptol or tea tree oil). Root canals were longitudinaly split and analized with stereomicroscope (15x magnification). The surface of the remaining filling material was measured using an image processing software. Results: There were no statistically significant differences in the area of residual filling material among used solvents, nor in applied technique. Retreatment with Reciproc instruments was significantly faster compared to retreatment using hand files. The manual retreatment technique was faster when tea tree essential oil was used as a solvent compared to eucalyptol. Conclusions: Australian tea tree oil and eucalyptus oil were equally effective in removing endodontic filling material, but none of canals were completely free of the residual filling material. Retreatment with Reciproc instruments was faster compared to retreatment using hand files. The manual retreatment technique is faster when tea tree essential oil is used as a solvent compared to eucalyptol., Uvod: Svrha ovog istraživanja bila je procijeniti trajanje revizije i učinkovitost eukaliptola i ulja čajevca pri strojnoj i ručnoj reviziji endodontskoga punjenja baziranoga na epoksidnoj smoli na izvađenim ljudskim zubima. Materijali i metode: U dvije skupine nasumično je podijeljeno 60 ljudskih jednokorijenskih zuba. Prva je pripremljena ručnim instrumentima, a druga s pomoću sustava Reciproc. Korijenski kanali punjeni su štapićima od gutaperke i pastom AH Plus. U prvoj skupini revizija je rađena proširivačima i instrumentima Hedström, a u drugoj skupini instrumentima Reciproc. Svaka skupina podijeljena je u dvije podskupine (n = 15) s obzirom na korišteno otapalo za reviziju (eukaliptol ili ulje čajevca). Korijenski kanali uzdužno su razrezani i analizirani stereomikroskopom (povećanje 15 x). Površina zaostatnoga materijala za punjenje izmjerena je u računalnom programu za obradu slike. Rezultati: Nije bilo statistički značajnih razlika u površini zaostatnoga punjenja ni među korištenim otapalima, ni u primijenjenoj tehnici. Revizija učinjena instrumentima Reciproc bila je znatno brža u usporedbi s revizijom ručnim instrumentima. Revizija ručnim instrumentima, u usporedbi s eukaliptolom, bila je brža kada se kao otapalo koristilo eterično ulje čajevca. Zaključak: Australsko ulje čajevca i ulje eukaliptusa bili su podjednako učinkoviti u uklanjanju endodontskoga punjenja, ali ni jedan kanal nije bio potpuno očišćen od zaostaloga materijala za punjenje. Revizija instrumentima Reciproc bila je brža u usporedbi s revizijom ručnim instrumentima. Revizija ručnim instrumentima bila je brža kada se eterično ulje čajevca koristilo kao otapalo u usporedbi s eukaliptolom.

Aim of the study: to evaluate root filling remnants after secondary root canal treatments (SRCTs) of oval-shaped canals with X-rays and cone beam computed tomography (CBCT). The SRCTs were performed using reciprocating NiTi instruments. Methods: Single-rooted teeth (N = 64) were randomly treated with Reciproc Blue (RB) and filled with AH Plus/single cone (SC group) or AH Plus/Guttafusion (GF group). After seven days of storage in HBSS (Hanks balanced salt solution), Gates Glidden burs #2/3 and RB #25 and #40 were used for the SRCTs. The time to complete the procedure was measured. X-rays and CBCT were used to calculate, respectively, the area and the volume occupied by the remnants in the coronal, middle, and apical thirds of each canal. Environmental scanning electron microscopy (ESEM) and energy dispersive X-ray spectroscopy (EDX) were used for qualitative evaluation and morphology composition of the remnants in sectioned roots. A statistical analysis was performed using Sigma Plot (version 13, IBM, Armonk, NY, USA). The study was designed according to PRILE guidelines. Results: After the SRCTs, the middle thirds of the root canals showed the presence of remnants in both groups, as demonstrated by X-rays and CBCT. The GF group showed a statistically significant higher volume of remnants than the SC Group only in the middle third. The ESEM supported by the EDX revealed the remnant composition by the detection of trace elements of sealer and gutta-percha in all root canals. Conclusion: The study demonstrated that the middle third of root canals is a critical region where remnants were packed and spread in the buccal-lingual sides of canals. ESEM-EDX detected a fine layer of filling remnants in all root thirds, suggesting a larger canal contamination than the X-rays and CBCT examinations revealed.

Antecedente: el uso de disolventes, tales como el Xilol, es frecuente durante el retratamiento endodóntico con el objetivo de facilitar la remoción de la gutapercha. Sin embargo, estos pueden afectar la microdureza y estructura de la dentina. Objetivo: evaluar el efecto del Xilol sobre la microdureza y la estructura química de la dentina luego del retiro de la gutapercha durante el retratamiento endodóntico, en premolares inferiores extraídos por indicación ortodóntica. Materiales y métodos: estudio experimental in vitro, que incluyó 12 dientes premolares unirradiculares extraídos para exodoncia por tratamiento ortodóntico. La muestra fue dividida aleatoriamente en dos grupos, seis para el grupo “control” que correspondió a dientes sin preparación biomecánica y seis para el grupo “expuesto” que correspondió a dientes desobturados con Xilol. Cada diente fue dividido longitudinamente en dirección vestibulolingual. En cada grupo, seis mitades fueron estudiadas con durometro de Vickers (HV) y tres con la espectroscopía de Raman. Resultados: la microdureza de la dentina fue similar entre los dientes sin y con exposición a Xilol, con un promedio reportado en la prueba de Vickers de 55.33.0 HV en el grupo control en comparación de 55.63.0 HV en el grupo expuesto a Xilol. En la prueba de Raman, no se observaron diferencias en la intensidad reportada a lo largo del espectro entre los grupos. En ambos casos, se reportó un pico máximo en 960 cm-1 correspondiente a niveles de hidroxiapatita. Conclusiones: los resultados de este estudio no sugieren cambios en la microdureza y en la estructura química de la dentina debido al uso de Xilol. Introduction: the use of solvents, such as Xylol, is common during endodontic retreatment in order to facilitate gutta-percha removal. However, they can affect dentin microhardness and dentin structure. Objectives: to evaluate the effect of Xylol on dentin microhardness and chemical structure after gutta-percha removal during endodontic retreatment in lower premolars extracted for orthodontic indication. Materials and methods: experimental in vitro study, which included 12 uniradicular premolars extracted for exodontia due to orthodontic treatment. The sample was randomly divided into two groups, six for the "control" group which corresponded to teeth without biomechanical preparation and six for the "exposed" group which corresponded to teeth treated with Xylol. Each tooth was split lengthwise in the vestibulolingual direction. In each group, six halves were studied with Vickers durometer (HV) and three with Raman spectroscopy. Results: dentin microhardness was similar between the teeth without and with Xylol exposure, with an average reported in Vickers test of 55.33.0 HV in the control group compared to 55.63.0 HV in the Xylol group. In the Raman spectroscopy, no differences were observed in the intensity along the spectrum between groups. In both cases, a maximum peak was recorded at 960 cm-1 corresponding to hydroxyapatite levels. Conclusions: the results of this study do not suggest changes in dentin microhardness and chemical structure due to the use of Xylol. Especialista en Endodoncia http://www.ustabuca.edu.co/ustabmanga/presentacion Especialización

Perforations during endodontic procedures are cited as the second greatest cause of treatment failures. Hence, when a perforation occurs, the goal should be to sterilize the site and then seal the perforation as soon as possible. Amongst the various available material, calcium silicate-based materials especially MTA is the most widely used for perforation repair due to its favourable cementogenic and osteogenic potential. The purpose of this case report is to describe endodontic retreatment and nonsurgical management of iatrogenic perforation in retreatment cases managed successfully with MTA-Angelus. Keywords: Iatrogenic perforation, Mineral trioxide aggregate, Endodontic retreatment, non-surgical repair.

Patients' experiences related to dental treatment could influence care-seeking behaviour and engender personal bias. Although endodontic retreatment and apical surgery are procedures often performed to manage previously treated teeth with persistent disease, there is lack of information regarding psycho-social perspectives of patients who undergo these treatments. Our aim was to compare experiences of patients who received these two treatment modalities using a qualitative approach.A purposive sample of patients was taken from our previous study utilizing the Oral Health Impact Profile to compare oral health-related quality of life of 150 patients who received retreatment and apical surgery. Patients who reported impact and no impact were invited to participate in focus group discussions (FGDs). Eighteen patients from the retreatment group and 15 patients from the surgical group participated in six FGDs. Thematic analysis was conducted to identify key themes.Four themes emerged: (1) psycho-social disability associated with dental procedures, (2) physical disability associated with dental problems, (3) reliance on dentist's advice for treatment and (4) self-management to preserve treated teeth. Patients undergoing endodontic retreatment reported significant time loss from work and were less informed of alternative treatment options. However, they were pleased with the aesthetics of their teeth, especially if new crowns were made. Patients undergoing surgery experienced anxiety related to loss of control during surgery and apprehension on visualizing the wound post-surgery. They reported more impact on their diet, social interaction and sleep quality and some felt self-conscious due to post-treatment gingival recession. Patients in both groups placed great trust in professional advice and expressed a clear desire to maintain their natural dentition. There was low awareness regarding long-term care and future sequelae of their treated tooth.Patients reported different psycho-social and physical impacts following endodontic retreatment and apical surgery. Patients undergoing endodontic retreatment were more satisfied with aesthetic outcomes but experienced greater impact related to complexities and length of time taken for treatment. Patients undergoing surgery were better informed of treatment options but experienced greater physical and psycho-social disability during the recovery phase. Clinicians could consider incorporating findings from this study into the patient-dentist discussion.

BACKGROUND: The complete removal of root filling material is one of the main goals of non-surgical endodontic retreatment. Thus, the development of new techniques and instruments aiming to promote this task presents clinical significance. AIM: The purpose of the study was to assess the amount of residual root canal filling materials (gutta-percha/sealer) after using two different endodontic retreatment systems and ultrasonic tip. METHODS: Forty-five mandibular premolar teeth were mechanically instrumented and obturated. Retreatment was performed using two different Endostar RE (Group 2), Rogin retreatment system (Group 3), and ultrasonic tip (Group 1). Roots were separated buccolingually into two halves. A digital camera connected to the stereomicroscope captured images to each half. Image-J software was used to evaluate and measure the areas with remaining filling material in each third (cervical, middle, and apical). RESULTS: Data analysis revealed significant differences between the groups in the coronal, middle, and apical thirds (p < 0.05). The ultrasonic retreatment tips (G1) were significantly more efficient in removing the gutta-percha and sealers compared to the Rogin (G3) and Endostar (G2) retreatment endodontic kits. CONCLUSIONS: All the file systems left some filling material in the canals. Ultrasonic retreatment tip had maximum efficacy for the removal of filling materials in comparison with the retreatment file systems under investigation.

This paper aims to describe a clinical case of surgical endodontic retreatment of a maxillary lateral incisor (tooth 12) with overfilling and extensive periapical lesion. A male patient was referred for endodontic retreatment of tooth 12. The intraoral examination revealed the presence of a fistula near teeth 11 and 12; and a positive response was obtained for the vertical percussion and mobility tests on tooth 12. The radiographic examination showed overfilling and an extensive radiolucent area associated with the root apex of teeth 11 and 12. In view of the history and radiographic findings, a computed tomography scan was requested. of conical beam, which showed great bone resorption in the apical region of tooth 12 with loss of buccal cortical bone and overfilling with gutta percha transposition through the apex of teeth 11 and 12. After consultations for failed endodontic retreatment, it was decided to perform a surgical endodontic retreatment with apical curettage, apicectomy, retrograde obturation and intracanal intraoperative obturation in tooth 12 and apicectomy with apical curettage in tooth 11. A Bio-C Repair bioceramic repair cement was used in the apical seal. During radiographic follow-up of 10 months, we can observe the absence of painful symptoms, of fistula and regression of the periapical lesion. Faced with persistent symptoms after conventional endodontic therapies, the endodontist should consider surgical treatment as a solution. Given the limitations, the correct management of this case can be attributed to the chosen surgical technique associated with the repair material used, which has excellent physicochemical and biological properties, which together helped to obtain the best possible result. Este trabajo tiene como objetivo describir un caso clínico de retratamiento endodóntico quirúrgico de un incisivo lateral maxilar (diente 12) con sobreobturación y lesión periapical extensa. Un paciente masculino fue remitido para retratamiento endodóntico del diente 12. El examen intraoral reveló la presencia de una fístula cerca de los dientes 11 y 12; y se obtuvo una respuesta positiva para las pruebas de percusión vertical y movilidad en el diente 12. El examen radiográfico mostró sobreobturación y una extensa área radiolúcida asociada con el ápice radicular de los dientes 11 y 12. En vista de la historia y los hallazgos radiográficos, se realizó una tomografía computarizada Se solicitó tomografía de haz cónico, que mostró gran reabsorción ósea en la región apical del diente 12 con pérdida de cortical vestibular y sobreobturación con transposición de gutapercha por el ápice de los dientes 11 y 12. Tras consultas por retratamiento endodóntico fallido, se decidió decidió realizar un retratamiento endodóntico quirúrgico con curetaje apical, apicectomía, obturación retrógrada y obturación intraoperatoria intracanal en el diente 12 y apicectomía con curetaje apical en el diente 11. En el sellado apical se utilizó un cemento de reparación biocerámico Bio-C Repair. Durante un seguimiento radiográfico de 10 meses, podemos observar la ausencia de síntomas dolorosos, de fístula y regresión de la lesión periapical. Ante la persistencia de los síntomas después de las terapias de endodoncia convencionales, el endodoncista debe considerar como solución el tratamiento quirúrgico. Dadas las limitaciones, el correcto manejo de este caso se puede atribuir a la técnica quirúrgica elegida asociada al material de reparación utilizado, el cual posee excelentes propiedades fisicoquímicas y biológicas, que en conjunto ayudaron a obtener el mejor resultado posible. Este trabalho tem como objetivo descrever um caso clínico de retratamento endodôntico cirúrgico de um incisivo lateral superior (dente 12) apresentando sobreobturação e extensa lesão periapical. Paciente do sexo masculino, foi encaminhado para realizar retratamento endodôntico do dente 12. Ao exame intra-oral observou-se a presença de fistula próximo aos dentes 11 e 12; e obteve-se resposta positiva para os testes de percussão vertical e mobilidade no dente 12. O exame radiográfico mostrou sobreobturação e área radiolúcida extensa associada ao ápice radicular dos dentes 11 e 12. Diante do histórico e dos achados radiográficos, foi solicitado uma tomografia computadorizada de feixe cônico, o qual mostrou grande reabsorção óssea na região apical do dente 12 com perda da cortical óssea vestibular e sobreobturação com transpasse de guta percha pelo ápice dos dentes 11 e 12. Após consultas para retratamento endodôntico falhos, optou-se por realizar um retratamento endodôntico cirúrgico com curetagem apical, apicetomia, obturação retrógrada e obturação intracanal transoperatória no dente 12 e apicetomia com curetagem apical no dente 11. Utilizou-se um cimento reparador biocerâmico Bio-C Repair no selamento apical. Durante acompanhamento radiográfico de 10 meses, podemos observar ausência de sintomatologia dolorosa, de fistula e regressão da lesão periapical. Diante de sintomatologias persistentes após terapias endodônticas convencionais, o endodontista deve considerar o tratamento cirúrgico como solução. Dada as limitações, o correto manejo desse caso pode ser atribuído a técnica cirúrgica escolhida associada ao material reparador utilizado, o qual apresenta excelentes propriedades físico-químicas e biológicas, que, juntos ajudaram a obter o melhor resultado possível.

Removal of intraradicular retainers often becomes an obstacle when endodontic retreatment is required. The aim of this study was to describe an endodontic reintervention preceded by the removal of intraradicular posts using the Integrated Simultaneous Ultrasound System (SISU) technique. Female patient, feoderma, 34 years old, was referred for dental care at the Specialization Clinic in Endodontics, Faculdade São Leopoldo Mandic, Belo Horizonte Unit, with indication for endodontic reintervention of dental elements 14 and 15, both with the presence of intraradicular post. In the initial radiographic examination, it was possible to observe a slight thickening of the periodontal ligament in tooth 14 and the presence of a radiolucent image in the region adjacent to the root apex, suggestive of a periapical lesion in tooth 15. After confirming the need and feasibility of endodontic retreatment, removal was performed. of the prosthetic crown, followed by partial wear of the cast metal cores and removal of the cement line with a fine tip ultrasonic insert. After this procedure, two ultrasonic thick tip inserts were used, positioned simultaneously in opposite directions, so that the ultrasonic vibrations were transferred to the intraradicular retainers, thus allowing their removal. Endodontic retreatment was performed in two sessions, with intracanal medication for a period of 21 days. Patient under clinical and radiographic follow-up. La remoción de los retenedores intrarradiculares a menudo se convierte en un obstáculo cuando se requiere un nuevo tratamiento endodóntico. El objetivo de este estudio fue describir una reintervención endodóntica precedida por la remoción de postes intrarradiculares utilizando la técnica Integrated Simultaneous Ultrasound System (SISU). Paciente femenina, feoderma, 34 años, fue remitida para atención odontológica en la Clínica de Especialización en Endodoncia, Facultad São Leopoldo Mandic, Unidad de Belo Horizonte, con indicación para reintervención endodóntica de los elementos dentarios 14 y 15, ambos con presencia de poste intrarradicular. En el examen radiográfico inicial se pudo observar un ligero engrosamiento del ligamento periodontal en el diente 14 y la presencia de una imagen radiolúcida en la región adyacente al ápice radicular, sugestiva de lesión periapical en el diente 15. Luego de confirmar la necesidad y la factibilidad del retratamiento endodóntico, se realizó la extracción de la corona protésica, seguido por el desgaste parcial de los núcleos metálicos fundidos y la extracción de la línea de cemento con un inserto ultrasónico de punta fina. Después de este procedimiento, se utilizaron dos insertos ultrasónicos de punta gruesa, colocados simultáneamente en direcciones opuestas, de modo que las vibraciones ultrasónicas fueran transferidas a los retenedores intrarradiculares, permitiendo así su remoción. El retratamiento endodóntico se realizó en dos sesiones, con medicación intracanal por un período de 21 días. Paciente en seguimiento clínico y radiográfico. A remoção de retentores intrarradiculares muitas vezes torna-se um obstáculo, quando há necessidade do retratamento endodôntico. O objetivo desse estudo foi descrever uma reintervenção endodôntica precedida de remoção de pinos intrarradiculares utilizando a técnica Sistema Integrado e Simultâneo de Ultrassom (SISU). Paciente do sexo feminino, feoderma, 34 anos, foi encaminhada para atendimento odontológico na clínica de Especialização em Endodontia, da Faculdade São Leopoldo Mandic, Unidade Belo Horizonte, com indicação de reintervenção endodôntica dos elementos dentários 14 e 15, ambos com presença de pino intrarradiculares. No exame radiográfico inicial, foi possível observar ligeiro espessamento do ligamento periodontal no dente 14 e presença de imagem radiolúcida na região adjacente ao ápice radicular, sugestiva de lesão periapical no dente 15. Após confirmada a necessidade e viabilidade do retratamento endodôntico, foi realizado a remoção da coroa protética, seguido do desgaste parcial dos núcleos metálicos fundidos e remoção da linha de cimentação com um inserto ultrassônico de ponta fina. Realizado esse procedimento, foram utilizados dois insertos ultrassônicos de ponta grossa, posicionados simultaneamente em direções opostas, de forma que as vibrações ultrassônicas fossem transferidas aos retentores intrarradiculares, permitindo, dessa forma, a remoção dos mesmos. Foi realizado o retratamento endodôntico em duas sessões, com medicação intracanal por um período de 21 dias. Paciente em acompanhamento clínico e radiográfico.

Orientador: Prof. Dr. Bruno Cavalini Cavenago Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências da Saúde, Programa de Pós-Graduação em Odontologia. Defesa : Curitiba, 28/03/2022 Inclui referências: p. 37-41 Resumo: A remoção do material obturador associada à desinfecção adequada do sistema de canais radiculares são fatores essenciais para aumentar o sucesso de um retratamento endodôntico. Incisivos inferiores classificados como tipo III de Vertucci (1-2-1) representam a segunda configuração mais prevalente neste grupo dentário. No entanto, ainda não há na literatura estudos sobre retratamento nesta condição anatômica específica. O objetivo do presente estudo foi avaliar a remoção de material obturador e desgaste das paredes dentinárias proporcionados por três diferentes sistemas de instrumentos mecânicos rotatórios em canais radiculares de incisivos inferiores com configuração anatômica tipo III de Vertucci. Foram utilizados 36 incisivos inferiores com a referida configuração, selecionados e pareados com o uso microtomografia computadorizada, sendo posteriormente preparados até um instrumento 40.04. Os canais radiculares foram obturados com a técnica do cone único empregando cones de guta percha 40.04 associados ao cimento AH Plus. Todos os espécimes foram escaneados por microtomografia computadorizada utilizando tamanho de voxel de 16,8 µm, após reconstrução foram avaliados o volume de material obturador (mm3) em 3 níveis a partir do vértice apical (1 - 4mm, 4 - 7 mm, 7 - 10 mm) e a espessura (mm) dentinária das paredes vestibular, lingual, mesial e distal em nos segmentos de 1mm, 3mm, 6mm e 9mm. Para a remoção do material obturador foi empregado o sistema Reciproc com os instrumentos R25 seguido do R40. Em seguida os canais foram divididos em 3 grupos (n = 12) e repreparados com os instrumentos 50.04 (Hyflex CM), 50.03 (Hyflex EDM) e 50.01 (Prodesign Locic). Os espécimes foram escaneados e reconstruídos após desobturação e novamente após o repreparo utilizando os mesmos parâmetros anteriores. Os dados de volume obtidos foram convertidos em porcentagem tomando como referência o volume pós-obturação. Os dados foram analisados estatisticamente considerando o nível de significância de 5%. Todos os espécimes apresentaram volume de material obturador remanescente similar (P>0.05) após a desobturação com o instrumento reciproc R40. O repreparo com instrumentos de diâmetro 0.50mm reduziu (P0.05) na remoção do material obturador e na espessura dentinária em todos os segmentos avaliados. Em todos os grupos as paredes V e L foram significativamente maiores do que as M e D. Foi possível concluir que os sistemas avaliados proporcionaram desempenho similar no retratamento proporcionando uma baixa porcentagem de remanescente de material obturador. Nesta situação, em que se realizou o preparo e obturação até diâmetro 0,40mm, o repreparo com instrumentos de diâmetro de ponta 0,50mm se mostrou eficiente na remoção de material obturador, evidenciando a importância clínica de uma maior dilatação do terço apical durante retratamento endodôntico. Os sistemas avaliados também foram similares no desgaste da estrutura dentinária, porém mesmo com uma maior dilatação não foi possível a completa remoção do material obturador nos canais de incisivos classificados como tipo III. Abstract: The filling material removal associated with adequate disinfection of the root canal system are essential factors to increase the predictability of an endodontic retreatment. Mandibular incisors classified as Vertucci type III (1-2-1) represent the second prevalence, however there are no studies showing endodontic retreatment in this anatomical configuration. The aim of the study was to evaluate filling material removal and dentin removal provided by different types of rotary instruments in root canals of mandibular incisors with Vertucci's III anatomical configuration. Thirty six mandibular incisor with referred configuration were used, selected and pairing with the use of microcomputed tomography, and thus prepared until a 40.04 instrument. The root canals were obturated with the single cone technique using gutta-percha cones 40.04 associated with AH Plus sealer. All samples were scanned by computed microtomography using a voxel size of 16.8 µm, after reconstruction were evaluated the filling material volume (mm3) at 3 levels from the apex (1 - 4 mm, 4 - 7 mm, 7 - 10 mm) and the dentinal thickness (mm) of the buccal, lingual, mesial and distal walls in the 1mm, 3mm, 6mm and 9mm segments. For the removal of filling material, the Reciproc system with instruments R25 followed by R40 was used, then the samples used were divided into 3 groups (n =12) and prepared with 50.04 (Hyflex CM), 50.3 (Hyflex EDM) and 50.01 (Prodesign Locic) instruments. The samples were scanned and reconstructed after desobturation and re-preparation using the same parameters as before. The volume data obtained was converted into using the post-filling volume as a reference. Data were statistically analyzed considering a 5% significance level. All of them presented similar volume of remaining filling material (P>0.05) after desobturation with the reciprocal instrument R40. The shaping with 0.50mm instruments (P0.05) in filling material removal and dentin thickness in all sections. In all groups the buccal and lingual walls were larger than mesial and distal walls. In this situation, in which preparation and obturation were performed up to 0.40 mm, re-preparation with instruments with a tip diameter of 0.50 mm proved to be an efficient removal of filling material, evidencing the clinical importance of dilatation of the apical third during endodontic retreatment. The evaluated systems were also similar for dentin thickness. Even with greater dilation, it was not possible to completely remove the filling material in the canals classified as type III.

To present a clinical case report of successful endodontic retreatment, in a maxillary first molar, with symptomatic apical periodontitis in the mesiobuccal root that had already undergone endodontic treatment and paraendodontic surgery. A patient was referred for evaluation of upper right first molar with swelling, severe pain and sensitivity to percussion and palpation. She reported having undergone endodontic treatment 1 year ago and, 6 months later, when the symptoms returned, a paraendodontic surgery was performed by the same professional. A cone-beam computed tomography (CBCT) was requested and the images showed extensive bone rarefaction associated with the mesiobuccal root, which had the MB1 canal treated and the MB2 canal untreated. The periapical region of the apices of the distobuccal and palatine roots showed signs of normality, and the treatment plan was established with selective endodontic retreatment only in the mesiobuccal root, with the location and treatment of the MB2 canal and retreatment of the MB1 canal. Retreatment was performed in 2 sessions with an intracanal dressing with calcium hydroxide paste. The canals were filled with Biodentine (BD, Septodont, Saint Maur de Fossés, France). Clinically, the patient had no further signs or symptoms and tomographic images showed evidence of bone repair after 24 months. Correct planning and execution of all phases of endodontic retreatment were fundamental for the success of this case report. Presentar un reporte de caso clínico de retratamiento endodóntico exitoso, en un primer molar superior, con periodontitis apical sintomática en la raíz mesio-vestibular que ya había sido sometido a tratamiento endodóntico y cirugía paraendodóntica. Un paciente fue remitido para evaluación del diente 16 con tumefacción, dolor intenso y sensibilidad a la percusión y palpación. Refiere haber tenido tratamiento de endodoncia durante 1 año y, 6 meses después, cuando reaparecieron los síntomas, se realizó una cirugía de paraendodoncia por el mismo profesional. Se solicitó una tomografía computarizada de haz cónico y las imágenes mostraron una extensa rarefacción ósea asociada a la raíz mesio-vestibular, que tenía el canal MV1 tratado y el canal MV2 sin tratar. El contorno de los ápices de las raíces disto-vestibulares y palatinas presentaba signos de normalidad, y se estableció el plan de tratamiento con retratamiento endodóntico selectivo solo en la raíz mesio-vestibular, con localización y tratamiento del canal MV2 y retratamiento del canal MV1. El retratamiento se realizó en 2 sesiones con un apósito permanente con hidróxido de calcio. Los canales se rellenaron con Biodentine (BD, Septodont, Saint Maur de Fossés, Francia). Clínicamente, el paciente no presentó más signos ni síntomas y las imágenes tomográficas mostraron evidencia de reparación ósea después de 24 meses. La correcta planificación y ejecución de todas las etapas del retratamiento endodóntico fueron fundamentales para el éxito de este reporte de caso. Apresentar um relato de caso clínico de sucesso no retratamento endodôntico, em um primeiro molar superior, com periodontite apical sintomática na raiz mesiovestibular que já havia passado por um tratamento endodôntico e cirurgia paraendodôntica. Uma paciente foi encaminhada para avaliação do dente 16 apresentando edema, dor forte e sensibilidade à percussão e palpação. Relatou a realização do tratamento endodôntico há 1 ano e, 6 meses após, quando o quadro sintomático retornou, foi realizada uma cirurgia paraendodôntica pelo mesmo profissional. Foi solicitada uma tomografia computadorizada de feixe cônico e as imagens mostraram extensa rarefação óssea associada à raiz mesiovestibular, que possuía o canal MV1 tratado e o canal MV2 sem tratamento. O contorno dos ápices das raízes distovestibular e palatina apresentavam sinais de normalidade, sendo estabelecido como plano de tratamento, o retratamento endodôntico seletivo apenas na raiz mesiovestibular, com a localização e tratamento do canal MV2 e retratamento do canal MV1. O retratamento foi realizado em 2 sessões com um curativo de demora com hidróxido de cálcio. Os canais foram obturados com o Biodentine (BD, Septodont, Saint Maur de Fossés, France). Clinicamente, a paciente não apresentou mais sinais ou sintomas e as imagens tomográficas mostraram evidências de reparo ósseo após 24 meses. Um correto planejamento e a execução de todas as etapas do retratamento endodôntico foram fundamentais para o êxito do presente relato de caso.

Background and Objectives: In the presence of a persistent endodontic lesion or endodontic failure, the alternative for the recovery of the dental element is endodontic retreatment or endodontic surgery, which consists in the surgical removal of the root apices with retrograde closure of the endodontium. The objective of this systematic review and meta-analysis was to provide an updated value of the Risk Ratio between the two types of treatment in order to offer to clinicians who propose a non-surgical endodontic retreatment or an endodontic surgery a direct comparison. Materials and Methods: The revision was performed according to PRISMA indications: three databases (PubMed, Scopus and Cochrane register) were consulted through the use of keywords relevant to the revision topic: surgical endodontic retreatment, endodontic retreatment, apicoectomy. This search produced 7568 records which, after eliminating duplicates and applying the inclusion and exclusion criteria, resulted in a total of seven included articles. The meta-analyses were conducted by applying fixed-effects models, given the low percentage of heterogeneity. In addition, trial sequency analysis (TSA) was performed for the analysis of the statistical power of the results and GRADE for the quality of the evidence. Results: The results of the meta-analyses’ data report an aggregate risk ratio (RR) between non-surgical endodontic retreatment and surgical endodontic retreatment of: 1.05 [0.74, 1.47] at one year of follow-up; RR 2.22 [1.45, 3.41] at two years of follow-up; an RR 1.08 [0.73 1.62] for a follow-up period of 3–4 years; and an RR 0.92 [0.53, 1.61] for a follow-up period of 8–10 years. Conclusions: The results of the present meta-analysis show that in the long term, the risk of failure is identical for the two groups, and there is only a slightly higher risk of failure for non-surgical endodontic retreatments, when only two years of follow-up are considered.