Microbial composition and diversity in intraradicular biofilm formed in situ: New concepts based on next-generation sequencing.

This study aimed to characterize the taxonomic composition of intraradicular multispecies biofilms (IMBs) formed in situ in a model to reproduce clinical conditions. Twelve palatal roots of maxillary molars had its canals prepared. Two roots were randomly selected to sterility control. Ten intraoral prosthetic appliances with lateral slots were fabricated. The roots were positioned in the slots with the canal access open to the oral cavity. Eight volunteers wore the appliance for 21 days, and two wore it at two different time points. One root from each appliance was removed and stored at -20°C until DNA extraction and sequencing (n = 10). Biofilm was analyzed using next-generation sequencing and bioinformatics. The V4 hyper-variable region of the 16SrRNA gene was amplified and sequenced. For data analyses, the mothur pipeline was used for 16SrRNA processing, and subsequent analyses of the sequence dataset were performed in R using the MicrobiomeAnalyst R package. The taxonomy-based analysis of bacterial communities identified 562 operational taxonomic units (OTUs), which belonged to 93 genera, 44 families, and 8 phyla. Bacterial colonization was different for each biofilm, and samples did not have the same group of bacteria. Alpha and beta diversity analysis revealed some general patterns of sample clustering. A core microbiome of prevalent OTUs and genera was identified. IMBs were heterogeneous when analyzed individually, but some diversity patterns were found after sample clustering. The experimental model seemed to reproduce the actual biofilm composition in endodontic infections, which suggests that it may be used to evaluate disinfection protocols.

Microbial composition and diversity in intraradicular biofilm formed in situ: New concepts based on next-generation sequencing.

This study aimed to characterize the taxonomic composition of intraradicular multispecies biofilms (IMB) formed in situ in a model to reproduce clinical conditions. Twelve palatal roots of maxillary molars had its canals prepared. Two roots were randomly selected to sterility control. Ten intraoral prosthetic appliances with lateral slots were fabricated. The roots were positioned in the slots with the canal access open to the oral cavity. Eight volunteers wore the appliance for 21 days, and two wore it at two different time points. One root from each appliance was removed and stored at -20°C until DNA extraction and sequencing (n = 10). Biofilm was analyzed using next-generation sequencing and bioinformatics. The V4 hyper-variable region of the 16SrRNA gene was amplified and sequenced. For data analyses, the mothur pipeline was used for 16SrRNA processing, and subsequent analyses of the sequence dataset were performed in R using the Microbiome Analyst R package. The taxonomy-based analysis of bacterial communities identified 562 operational taxonomic units (OTUs), which belonged to 93 genera, 44 families, and 8 phyla. Bacterial colonization was different for each biofilm, and samples did not have the same group of bacteria. Alpha and beta diversity analysis revealed some general patterns of sample clustering. A core microbiome of prevalent OTUs and genera was identified. IMBs were heterogeneous when analyzed individually, but some diversity patterns were found after sample clustering. The experimental model seemed to reproduce the actual biofilm composition in endodontic infections, which suggests that it may be used to evaluate disinfection protocols.

Histological effects of photobiomodulation on delayed tooth replantation: a systematic review.

This systematic review evaluated preclinical studies to assess whether PBM has a more favorable histological response than other treatments used before delayed replantation of avulsed teeth. This review followed the PRISMA checklist and was registered in PROSPERO. MEDLINE (PubMed), Embase, Scopus and Web of Science were searched from their inception to July 14, 2022. Data were independently extracted by two reviewers. Data were collected about species, number of animals, number and type of teeth, groups evaluated, extra-alveolar time, parameters for PBM and other study groups, presence and characteristics of containment, observation time points, evaluation methods, characteristics evaluated, and significant results. The ARRIVE and SYRCLE tools were used to assess the methodological quality and risk of bias (RoB) of the studies. After screening, six studies were included in the review synthesis. Three of the four studies that evaluated root resorption as an outcome found that PBM decreases its occurrence after delayed tooth replantation. A meta-analysis was not conducted because some data were missing in the included studies. Half of the studies evaluating ankylosis found an increase in its occurrence after PBM. Two studies evaluated inflammatory responses and found a reduction of inflammation after PBM. In general, studies had high methodological heterogeneity, intermediate reporting quality and high RoB. Despite the methodological quality and RoB limitations of the studies, the histological responses after delayed tooth replantation were more favourable in the PBM groups. Preclinical studies supported by guidelines should define laser parameters for future clinical studies.

Does aPDT reduce bacterial load in endodontic infected teeth? A systematic review and meta-analysis.

This systematic review investigated whether antimicrobial photodynamic therapy (aPDT) after chemomechanical root canal disinfection (CD) yields a greater microbial load reduction than only CD. An electronic literature search was conducted on four databases up to November 2022, with no language or publication date restrictions. Randomized and non-randomized clinical trials were included if participants had a primary endodontic infection in permanent teeth, and if microbial loads before and after using aPDT were compared. Two researchers independently screened titles and abstracts to determine study eligibility. Assessments included risk of bias and methodological quality. This review was registered in PROSPERO (CRD42020181783). Eight studies were included in the qualitative analysis, and six were eligible for meta-analysis. In the random effects model, aPDT significantly improved the results of root canal disinfection when compared with standard protocols for cleaning and shaping (p = 0.04, 95% CI -1.72, -0.05). Subgroup analysis suggested that aPDT has a better effect on reducing the load of anaerobic microorganisms (p = 0.003, 95% CI -3.36, -0.69). The use of aPDT as an adjunct to chemomechanical disinfection promotes additional reduction of the microbial load and, therefore, seems to improve the results of root canal treatments in permanent teeth with a primary endodontic infection. However, certainty of evidence should be improved.

Impact of COVID-19 pandemic on completed treatments and referrals during urgent dental visits.

This ecological study assessed the impact of the COVID-19 pandemic on completed treatments (CTs) and referrals during urgent dental visits to primary health care units in Brazil, and their associations with socioeconomic, geodemographic, and pandemic index factors in Brazilian municipalities. The difference in rates of procedures 12 months before and during the pandemic was calculated. Data were extracted at baseline from health information systems of all municipalities that provided urgent dental care (n = 5,229 out of 5,570). Multiple logistic regression predicted the factors associated with referrals and CTs. The number of dental urgencies increased from 3,987.9 to 4,272.4 per 100,000 inhabitants. The rates of referrals decreased in 44.1% of the municipalities, while 53.9% had lower rates of CTs. Municipalities with a greater number of oral health teams in the primary health care system (OR = 1.52, 95%CI:1.21-1.91) and with specialized services (OR = 1.80, 95%CI:1.50-2.16) were more likely to decrease referrals during the pandemic. Higher HDI and GDP per capita were associated with a larger decrease in referrals and smaller decrease in CTs. The calamity generated by the long pandemic period resulted in a greater demand for urgent visits. Less developed and larger cities seem to have been more likely to not complete treatments during urgent visits in primary dental care units in times of calamity. Primary dental care offices in smaller and less developed municipalities should be better equipped to provide appropriate assistance and to improve the problem-solving capacity of dental services during emergencies.

Tip and taper compatibility of accessory gutta-percha points with rotary and reciprocating instruments.

Objectives: This study was conducted to evaluate and compare the tip and taper compatibility of accessory gutta-percha points (AGPs) with various rotary and reciprocating instruments. Materials and Methods: Using a profile analyzer, tip and taper measurements were taken of 10 AGPs of each of the 14 models available from Odous de Deus and the 4 models available from Dentsply-Maillefer. Diameter measurements were taken at 1-mm intervals, from 3 mm from the tip (D3) to 16 mm. Results: Based on the mean values obtained, 3-dimensional (3D) models of the AGPs were drawn in Autodesk Fusion 360 and superimposed on 3D models of each instrument selected (Mtwo, Reciproc, RaCe, K3, and ProDesign Logic) to determine the compatibility between the instrument and the AGP. Data corresponding to the tips and tapers of the various AGPs, as well as the tip and taper differences between the AGPs and the instruments, were analyzed using descriptive statistics. The tapers of the AGPs were subject to the American National Standards Institute/American Dental Association No. 57 standard. The Odous de Deus extra-long medium and extra-long extra-medium AGPs were shown to be compatible with Mtwo, K3, and ProDesign Logic instruments with taper 0.06 and tip sizes 25 and 30, while the Dentsply fine and fine medium cones were compatible with Mtwo, RaCe, and K3 instruments with conicity of 0.04 and tip sizes 35 and 40. Conclusions: Both the Odous de Deus and Dentsply commercial brands included 2 AGP models with tip (D3) and taper compatibility with Mtwo, RaCe, K3, and/or Prodesign Logic instruments.

Effect of different disinfection protocols in bacterial viability of an intraradicular biofilm formed in situ.

The present study aimed to evaluate bacterial viability after the use of different disinfection protocols in root canals infected with a multispecies biofilm (MB) formed in situ. Palatal roots with a single canal were obtained from extracted maxillary molars and sterilized before being inserted into the mouth. The roots were contaminated with a MB in an intraoral appliance worn by ten volunteers. All volunteers wore six roots simultaneously in two intraoral devices for 21 days. One root from each volunteer was assigned to each group (n=10): PUI - passive ultrasonic irrigation; EC - Easy Clean; XPF - XP-endo Finisher; aPDT - antimicrobial photodynamic therapy; CI - conventional irrigation; and NC - negative control. The samples were evaluated under confocal laser scanning microscopy. The percentage of viable cells (VC) was calculated over the total percentage of MB biovolume. Data were statistically analyzed (α=5%). The cell viability in the entire root canal or for each third was compared between groups (Kruskal-Wallis test, Dunn post-hoc test) and for the same group (Friedman test, Dunn post-hoc test). Disinfection protocols were not significantly different from each other (P>.05). Samples in EC, PUI, and aPDT had lower cell viability than in NC (P<.05). In the coronal third of samples in the EC, XPF, PUI and aPDT, the percentage of VC biovolume was lower than in the NC (P<.05). The percentage of VC in EC samples was lower in the coronal and middle thirds than in the apical third (P<.05). EC, PUI and aPDT had significant effects on cell viability in intraradicular multispecies biofilm formed in situ when compared with untreated samples.

Effect of different disinfection protocols in bacterial viability of an intraradicular biofilm formed in situ

Abstract The present study aimed to evaluate bacterial viability after the use of different disinfection protocols in root canals infected with a multispecies biofilm (MB) formed in situ. Palatal roots with a single canal were obtained from extracted maxillary molars and sterilized before being inserted into the mouth. The roots were contaminated with a MB in an intraoral appliance worn by ten volunteers. All volunteers wore six roots simultaneously in two intraoral devices for 21 days. One root from each volunteer was assigned to each group (n=10): PUI - passive ultrasonic irrigation; EC - Easy Clean; XPF - XP-endo Finisher; aPDT - antimicrobial photodynamic therapy; CI - conventional irrigation; and NC - negative control. The samples were evaluated under confocal laser scanning microscopy. The percentage of viable cells (VC) was calculated over the total percentage of MB biovolume. Data were statistically analyzed (α=5%). The cell viability in the entire root canal or for each third was compared between groups (Kruskal-Wallis test, Dunn post-hoc test) and for the same group (Friedman test, Dunn post-hoc test). Disinfection protocols were not significantly different from each other (P>.05). Samples in EC, PUI, and aPDT had lower cell viability than in NC (P<.05). In the coronal third of samples in the EC, XPF, PUI and aPDT, the percentage of VC biovolume was lower than in the NC (P<.05). The percentage of VC in EC samples was lower in the coronal and middle thirds than in the apical third (P<.05). EC, PUI and aPDT had significant effects on cell viability in intraradicular multispecies biofilm formed in situ when compared with untreated samples.

Resumo O presente estudo teve como objetivo avaliar a viabilidade bacteriana após o uso de diferentes protocolos de desinfecção em canais radiculares infectados com um biofilme multiespécies (MB) formado in situ. Raízes palatinas com canal único foram obtidas de molares superiores extraídos e esterilizadas antes de serem inseridas na boca. As raízes foram contaminadas com MB em um aparelho intraoral usado por dez voluntários. Todos os voluntários usaram seis raízes simultaneamente em dois dispositivos intrabucais por 21 dias. Uma raiz de cada voluntário foi atribuída a cada grupo (n=10): PUI - irrigação ultrassônica passiva; EC - Easy clean; XPF - XP-endo Finisher; aPDT - terapia fotodinâmica antimicrobiana; IC - irrigação convencional; e, NC - controle negativo. As amostras foram avaliadas em microscopia confocal de varredura a laser. A porcentagem de células viáveis (VC) foi calculada sobre a porcentagem total do biovolume de MB. Os dados foram analisados estatisticamente (α=5%). A viabilidade celular em todo o canal radicular ou em cada terço foi comparada entre os grupos (teste de Kruskal-Wallis, teste post-hoc de Dunn) e no mesmo grupo (teste de Friedman, teste post-hoc de Dunn). Os protocolos de desinfecção não foram significativamente diferentes entre si (P>0,05). Amostras dos grupos EC, PUI e aPDT apresentaram menor viabilidade celular do as do NC (P<0,05). No terço cervical das amostras do EC, XPF, PUI e aPDT, a porcentagem de biovolume de VC foi menor do que no NC (P<0,05). A porcentagem de VC nas amostras do EC foi menor nos terços cervical e médio do que no terço apical (P<0,05). EC, PUI e aPDT tiveram efeitos significativos na viabilidade celular do biofilme multiespécies intrarradicular formado in situ quando comparado com amostras não tratadas. Estudos clínicos devem investigar o papel da redução de cargas bacterianas viáveis no sistema de canais radiculares para o sucesso do tratamento endodôntico.

Cytotoxicity, biocompatibility and osteoinductive profile of an MTA-hydrogel-based cement: An in vitro and animal study.

AIM: This study aimed to evaluate the cytotoxicity, biocompatibility and osteoinductive profile of a mineral trioxide aggregate (MTA)-hydrogel-based material (MTA Flow) in comparison with MTA Angelus. METHODOLOGY: Cell viability was evaluated in human periodontal ligament stem cells (hPDLSCs) using the methyl-thiazol-tetrazolium (MTT) colourimetric assay. Polyethylene tubes containing the tested materials and empty polyethylene tubes (control) were implanted in the subcutaneous tissue of Wistar rats. Cellular (lymphocyte infiltration) and extracellular events (ECM; collagen fibres) were analysed in histological sections. Immunohistochemical (collagen I, osteopontin, bone sialoprotein, bone morphogenetic protein4) analyses were also performed. RESULTS: At 24, 48 and 72 h, all tested groups showed cell viability similar to control (p > .05). Regarding biocompatibility, all groups showed similar cellular events represented by a slight inflammatory reaction characterized by hyperaemia and a mild lymphocytic inflammatory infiltrate. The analysis of lymphocytes during the time showed a decrease in these cells in the control group and a significant interaction between MTA Angelus and control (p < .001), with MTA Angelus showing a more extensive inflammatory infiltrate. Regarding fibres, an increase in content was observed in all groups during the experimental time (7, 30 and 60 days), however, no difference was detected among the experimental groups (p = .063). After 60 days, the immunoexpression of bone matrix proteins in the MTA Flow group was similar to or higher than that observed in the MTA Angelus and in the control group. CONCLUSIONS: MTA Flow showed a non-cytotoxic behaviour, biocompatibility and ability to stimulate tissue mineralization.

Impact of COVID-19 pandemic on completed treatments and referrals during urgent dental visits

Abstract This ecological study assessed the impact of the COVID-19 pandemic on completed treatments (CTs) and referrals during urgent dental visits to primary health care units in Brazil, and their associations with socioeconomic, geodemographic, and pandemic index factors in Brazilian municipalities. The difference in rates of procedures 12 months before and during the pandemic was calculated. Data were extracted at baseline from health information systems of all municipalities that provided urgent dental care (n = 5,229 out of 5,570). Multiple logistic regression predicted the factors associated with referrals and CTs. The number of dental urgencies increased from 3,987.9 to 4,272.4 per 100,000 inhabitants. The rates of referrals decreased in 44.1% of the municipalities, while 53.9% had lower rates of CTs. Municipalities with a greater number of oral health teams in the primary health care system (OR = 1.52, 95%CI:1.21-1.91) and with specialized services (OR = 1.80, 95%CI:1.50-2.16) were more likely to decrease referrals during the pandemic. Higher HDI and GDP per capita were associated with a larger decrease in referrals and smaller decrease in CTs. The calamity generated by the long pandemic period resulted in a greater demand for urgent visits. Less developed and larger cities seem to have been more likely to not complete treatments during urgent visits in primary dental care units in times of calamity. Primary dental care offices in smaller and less developed municipalities should be better equipped to provide appropriate assistance and to improve the problem-solving capacity of dental services during emergencies.

Impact of Particle Size on the Setting Behavior of Tricalcium Silicate: A Comparative Study Using ISO 6876 Indentation Testing and Isothermal Induction Calorimetry.

This study examines the impact of particle size on the setting behavior of tricalcium silicate powders. The setting behavior was evaluated using ISO 6876 indentation testing and isothermal induction calorimetry techniques. The objective was to compare the outcomes obtained from these methods and establish a correlation between particle size and setting characteristics. The cement pastes were manually mixed with a water-to-solid ratio of 0.66 for conducting indentation tests according to ISO 6876, while calorimetry measurements were performed using isothermal (conduction) calorimetry at room temperature. The findings demonstrate a significant influence of smaller particle sizes on accelerating the hydration process of cement pastes, resulting in a reduction of setting time by up to 24%. Moreover, the final setting times obtained through the indentation method closely approximate the inflection points of the acceleration curves acquired by calorimetry, with time deviations of less than 12% regardless of particle size.

Physicochemical properties of three bioceramic cements.

This study aimed to compare the physicochemical properties of MTA Angelus (MTA-A), MTA Repair HP (MTA-HP), and Biodentine (BD). Setting times (n = 7) were determined in accordance with ASTM C266-15. Solubility (n = 11), pH (n = 10), and calcium ion release (n = 10) were evaluated up to 28 days in accordance with ANSI/ADA specification no. 57. Radiopacity was assessed by ANSI/ADA (n = 10) and the tissue simulator method (n = 10). In both methods, the specimens were radiographed using an aluminum stepwedge and the digital radiographs were analyzed in Adobe Photoshop, determining the mean grayscale pixel values of the materials, of the 3-mm aluminum stepwedge, and of the dentin, the latter of which was analyzed on the tissue simulator. The data obtained from each test were statistically analyzed and compared (p < 0.05). MTA-A presented longer final setting time compared with the other materials. There were no significant differences in the mass values of materials during the experiment. All materials presented an alkaline pH. BD promoted greater calcium ion release in most of the experimental periods. All materials presented appropriate radiopacity. BD showed lower radiopacity than MTA-A in the tissue simulator method. All groups presented higher radiopacity in the tissue simulator when compared with the ANSI/ADA method. MTA-A, MTA-HP, and BD showed appropriate physicochemical properties and radiopacity, and were considered suitable to be used in clinical practice.

XP Endo Finisher-R and PUI as supplementary methods to remove root filling materials from curved canals.

This study assessed the ability of XP-endo Finisher R (FKG, La Chaux-de-Fonds, Switzerland) to remove filling remnants from curved mesiobuccal canals of maxillary molars, using the passive ultrasonic irrigation (PUI) technique as a comparison. Twenty-four curved main mesiobuccal canals (MB1) of maxillary molars were instrumented with Wave One (#25/07) and filled with gutta-percha points and AH Plus Sealer. Samples were then re-treated with a standardized protocol with Wave One (#35/06) as the master apical file. Micro-CT scans measured baseline volume of remaining filling material (in mm3). Samples were divided into two groups (n = 12) according to the supplementary cleaning approach: (PUI) or XP-endo Finisher R. Statistics compared baseline and final volume of filling material (within-group); and the percentage of filling material reduction (between-group). Mean baseline volumes, final volumes, and percentages of reduction (%) of filling material for XP-endo Finisher R and PUI were respectively: 0.060 mm3, 0.042 mm3, and 31.28%; and 0.064 mm3, 0.054 mm3, and 16.57%. Both tested protocols reduced the amount of filling material (p < 0.05). XP-endo Finisher R had higher percentage of reduction as compared to PUI (p < 0.05). XP-endo Finisher R and PUI used as supplementary cleaning protocols during re-treatment improved the removal of root filling material in curved canals; but XP-endo Finisher R was approximately twice more efficient. The complete filling material removal during re-treatment procedures is still a challenge. Supplementary cleaning protocols may help to remove the remaining material after the complete mechanical preparation of curved canals. XP-endo Finisher R was approximately twice more efficient than PUI.

Evaluation of the biological and physicochemical properties of calcium silicate-based and epoxy resin-based root canal sealers.

Biocompatibility, dimensional stability, radiopacity, flow, and low solubility are the characteristics of an ideal endodontic sealer. This study evaluated and compared in vivo and in vitro biological and physicochemical properties of calcium silicate-based sealers: Sealer Plus BC (BC), MTA Fillapex (MF); and resin-based sealers: AH Plus (AHP) and Sealer Plus (SP). Apical papilla cells were exposed to sealer extracts and subjected to MTT, SRB, scratch, alkaline phosphatase enzyme activity (ALP) and Alizarin red staining (ALZ) assays. Sealers were histologically evaluated in connective tissue of Wistar rats in different periods. Radiopacity, film thickness, flow, setting time, pH and element analyses were investigated. BC had better results compared to AHP and MF at hour 72 for MTT assay (p < .05), and the highest cell viability under SRB (p < .05). All sealers presented ALP activity. BC presented the highest mineralized deposition under ALZ (p < .05). BC and MF promoted wound healing. All sealers induced an initial inflammation reaction that decreased over time. Eosinophils were observed at day 7 in MF (p < .05). Despite MF did not present final setting time, the sealers properties were in accordance to ISO 6876/2012 and ASTM C266-08. All sealers presented cell viability and biocompatibility. BC presented higher pH values and bioactivity. The materials tested showed physico-chemical properties in accordance with standards, except for MF setting time.

Apical extrusion of sodium hypochlorite in immature teeth: comparison of three different cleaning protocols.

This study compared standard needle irrigation, passive ultrasonic irrigation, XP-Endo Finisher and Easy Clean in the apical extrusion of sodium hypochlorite (NaOCl) in a model simulating immature teeth. Ten bovine teeth were maintained in suspension in a container with the apical portion in contact with 0.2% agarose gel containing 0.1% metacresol purple. The canals were irrigated with 2.5% NaOCl, according to each irrigation protocol. After 3 min, apical extrusion of NaOCl was observed by the colour gel change when in contact with NaOCl. The containers were photographed, and the NaOCl extrusion area was measured. All protocols showed NaOCl extrusion, providing similar area (P > 0.05). Considering the similarity among the studied protocols, all of them can be considered during the endodontic treatment of immature teeth. Further studies on the particularities of immature teeth should be performed to evaluate cell viability, cleaning efficiency, disinfection capacity and dentin removal promoted by the irrigation protocols.

Physicochemical properties of three bioceramic cements

Abstract: This study aimed to compare the physicochemical properties of MTA Angelus (MTA-A), MTA Repair HP (MTA-HP), and Biodentine (BD). Setting times (n = 7) were determined in accordance with ASTM C266-15. Solubility (n = 11), pH (n = 10), and calcium ion release (n = 10) were evaluated up to 28 days in accordance with ANSI/ADA specification no. 57. Radiopacity was assessed by ANSI/ADA (n = 10) and the tissue simulator method (n = 10). In both methods, the specimens were radiographed using an aluminum stepwedge and the digital radiographs were analyzed in Adobe Photoshop, determining the mean grayscale pixel values of the materials, of the 3-mm aluminum stepwedge, and of the dentin, the latter of which was analyzed on the tissue simulator. The data obtained from each test were statistically analyzed and compared (p < 0.05). MTA-A presented longer final setting time compared with the other materials. There were no significant differences in the mass values of materials during the experiment. All materials presented an alkaline pH. BD promoted greater calcium ion release in most of the experimental periods. All materials presented appropriate radiopacity. BD showed lower radiopacity than MTA-A in the tissue simulator method. All groups presented higher radiopacity in the tissue simulator when compared with the ANSI/ADA method. MTA-A, MTA-HP, and BD showed appropriate physicochemical properties and radiopacity, and were considered suitable to be used in clinical practice.

XP Endo Finisher-R and PUI as supplementary methods to remove root filling materials from curved canals

Abstract: This study assessed the ability of XP-endo Finisher R (FKG, La Chaux-de-Fonds, Switzerland) to remove filling remnants from curved mesiobuccal canals of maxillary molars, using the passive ultrasonic irrigation (PUI) technique as a comparison. Twenty-four curved main mesiobuccal canals (MB1) of maxillary molars were instrumented with Wave One (#25/07) and filled with gutta-percha points and AH Plus Sealer. Samples were then re-treated with a standardized protocol with Wave One (#35/06) as the master apical file. Micro-CT scans measured baseline volume of remaining filling material (in mm3). Samples were divided into two groups (n = 12) according to the supplementary cleaning approach: (PUI) or XP-endo Finisher R. Statistics compared baseline and final volume of filling material (within-group); and the percentage of filling material reduction (between-group). Mean baseline volumes, final volumes, and percentages of reduction (%) of filling material for XP-endo Finisher R and PUI were respectively: 0.060 mm3, 0.042 mm3, and 31.28%; and 0.064 mm3, 0.054 mm3, and 16.57%. Both tested protocols reduced the amount of filling material (p < 0.05). XP-endo Finisher R had higher percentage of reduction as compared to PUI (p < 0.05). XP-endo Finisher R and PUI used as supplementary cleaning protocols during re-treatment improved the removal of root filling material in curved canals; but XP-endo Finisher R was approximately twice more efficient. The complete filling material removal during re-treatment procedures is still a challenge. Supplementary cleaning protocols may help to remove the remaining material after the complete mechanical preparation of curved canals. XP-endo Finisher R was approximately twice more efficient than PUI.

Periodontite apical assintomática com rompimento de cortical óssea em paciente sob tratamento contínuo com isotretinoína: relato de caso / Asymptomatic apical periodontitis with cortical bone disruption in patient under continuous treatment with Isotretinoin: case report

Introdução: A periodontite apical assintomática (PAA) é caracterizada pela inflamação e destruição dos tecidos periapicais, e sua progressão promove reabsorção óssea, podendo ser agravada pelo uso contínuo de isotretinoína. Objetivo: O objetivo do presente estudo foi relatar a resolução de uma PAA com rompimento de cortical óssea mandibular em um paciente sob tratamento contínuo com isotretinoína (Roacutan®), por meio de procedimentos químicos-mecânicos convencionais e controle com tomografia computadorizada de feixe cônico (TCFC). Descrição: Um paciente com 21 anos de idade, ASA I, em tratamento contínuo com isotretinoína, procurou atendimento odontológico com moderada dor na região do elemento dental #38. Após exames clínicos, radiográficos e tomográficos, verificou-se a necessidade de tratamento endodôntico do dente #36. A TCFC mostrou uma imagem apical extensa e hipodensa entre os dentes #36 e #37, compatível com lesão cística óssea, com dimensões de 25,59 mm (largura) x 14,37 mm (altura) x 8,40 mm (profundidade). Também foram observados reabsorção apical da raiz distal, halo hipodenso sob a restauração coronal do #36 e ruptura da cortical externa vestibular e lingual. O tratamento endodôntico foi realizado em três sessões, com auxílio de um microscópio operatório e protocolos químicos-mecânicos, como Easy Clean e terapia fotodinâmica. Resultado: A resolução da PAA foi observada após acompanhamento por três anos. Conclusão: O tratamento endodôntico permitiu o reparo de uma lesão periapical extensa, evitando a cirurgia parendodôntica imediata, e o uso contínuo de isotretinoína não afetou a resolução da PAA(AU).

Introduction: Asymptomatic apical periodontitis (AAP) is characterized by inflammation and destruction of the periapical tissues and its progression leads to bone resorption, which may be aggravated by continuous use of Isotretinoin. The objective of this study was to report the resolution of AAP with mandibular cortical disruption in a patient under continuous treatment with isotretinoin (Roacutan®) and kickboxing practitioner, by conventional chemical-mechanical procedures and cone-bean computed tomography (CBCT) follow-up. Description: A 21-year-old Caucasoid individual, ASA I, under continuous use of isotretinoin and kickboxing practitioner sought dental care with moderate pain at the region of tooth #38. After clinical, radiographic and tomographic examination, the need for endodontic treatment of tooth #36 was verified. The CBCT showed an extensive and hypodense apical image between teeth #36 and #37, compatible with cystic bone lesion, with dimensions of 25.59 mm wide x 14.37 mm high x 8.40 mm deep. Apical resorption of the distal root, hypodense halo under a coronal restoration at #36, and rupture of the external buccal and lingual cortical bone were also observed. The endodontic treatment was performed in three sessions with the aid of a microscope and chemical-mechanical protocols, such as Easy Clean and photodynamic therapy. Result: Resolution of AAP was observed after follow-up for three years. Conclusion: Endodontic treatment allowed healing of an extensive periapical lesion, avoiding immediate parendodontic surgery and the continuous use of isotretinoin did not affect the AAP resolution. (AU).

Marginal gaps and internal voids after root-end filling using three calcium silicate-based materials: A Micro-CT analysis.

This study evaluated the 3D quality of root-end filling, assessing the presence (volume and percentage) of marginal gaps and internal voids formed after retro-filling with three calcium silicate-based materials: MTA Angelus (Angelus Soluçoes Odontologicas, Londrina, PR, Brazil), Biodentine (Septodont Ltd., Saint Maur-des-Faussés, France) and Neo MTA Plus (Avalon Biomed Inc., Bradenton, Florida, US). Thirty human, extracted, single rooted teeth were used. Orthograde root canal treatment, root resection (3mm shorter than the apex) and retrograde cavity preparation with ultrasonic tips were performed. Teeth were divided into 3 groups (n =10 each) following a stratified randomization according to the initial volume of the root-end cavity. After retrofilling, samples were stored for 7 days. Then, two rounds of micro-CT scans were performed: soon after root-end preparation (with the cavity still empty) and 7 days after root-end filling. Marginal gaps, internal voids volume (mm3 and %), as well as, the overall defects (sum of gaps and voids) were evaluated. Statistics compared the three groups in relation to those defects. There was not statistical difference between groups regarding the marginal gaps (P≥ 0.05), the internal voids (P≥ 0.05), and the overall defects (P≥ 0.05). Median (mm3) and % of overall air-entrapment defects (gaps and/or voids) was: 0.004mm3 and 1.749% for MTA Angelus, 0.018mm3 and 6.660% for Biodentine, and 0.012mm3 and 4.079% for Neo MTA Plus. All materials had gaps and/or voids. No differences were found between MTA Angelus, Biodentine and Neo MTA Plus.