Effect of obturation technique on dentinal tubule penetration of two tricalcium silicate-based sealers: Ex vivo study.

The aim of this study was to assess by confocal laser microscope the depth of dentinal tubule penetration of two tricalcium silicate-based sealers promoted by two obturation techniques in curved canals compared with AHPlus. One hundred and twenty canals were divided into six groups (n = 20): BCSC-Bio-C Sealer (BC) and single-cone technique (SC); BCCW-BC and continuous condensation wave (CW); TFSC-Total Fill (TF) and SC; TFCW-TF and CW; AHSC-AH Plus (AH) and SC; AHCW-AH and CW. Data were analysed using the three-way ANOVA and Tukey's test (α = 5%). Penetration depth was significantly greater for TFCW than TFSC and greater for AHCW than AHSC (p < 0.05). There was no significant difference between BCCW and BCSC (p > 0.05). The penetration of TF was significantly greater (p < 0.05). The CW technique promoted greater intratubular penetration, except for the BC sealer.

Evaluation of the Ability of 3 Reciprocating Instruments to Remove Obturation Material: A Micro-Computed Tomography Study.

INTRODUCTION: The purpose of this study was to evaluate the ability of the Reciproc, Reciproc Blue, and WaveOne Gold systems to remove filling material during endodontic retreatment of extracted human mandibular premolars. METHODS: Thirty-nine teeth were instrumented with the Protaper Universal System to the F3 file and filled with the Tagger hybrid technique using an F3 gutta-percha cone and AH Plus cement. At the end of this period, the teeth were scanned with micro-computed tomography before and after removal of the filling material from the root canals. The teeth were divided into 3 groups (n = 13) based on the apical volume, depending on the systems used to remove the filling material. Group GR: Reciproc 40/.06; Group GRB: Reciproc Blue 40/.06; and Group GWG: WaveOne Gold 35/.06. The results were statistically analyzed using the tests of Kruskal-Wallis, Duncan, and analysis of variance at a significance level of 5%. RESULTS: The results showed that there were no significant differences between the amounts of filling material removed, either for the apical and middle regions alone or in the overall evaluation for the 3 groups (P = .97). The time evaluation statistically showed that the GR and GWG groups required less time to clean the root canals than the GRB group. CONCLUSIONS: Reciproc R40 files and WaveOne Gold Medium files required less time for endodontic treatment than Reciproc Blue R40 files. There was no difference in the ability to remove obturation material between the 3 instruments. No instrument was able to completely remove the filling material from the root canals.

Comparative in vitro analysis of the antifungal activity of different calcium silicate-based endodontic sealers

Aim: This study aimed to perform an in vitro comparative analysis of the antifungal activity of different calcium silicate-based endodontic sealers against three fungal species. Methods: The antifungal properties of three calcium silicate-based sealers were tested: Bio-C Sealer, Cambiar a Sealer Plus BC, and MTA-Fillapex. Two commonly used sealers were used as controls: AH Plus and Endomethasone. An agar diffusion test was performed to analyze the antifungal activity of the sealers against Candida albicans, Candida glabrata, Candida tropicalis, and a mixed microbial culture medium. The results were analyzed using ANOVA (p <0.05). Results: Endomethasone exhibited the highest inhibition against all strains examined, maintaining a consistent level of inhibition throughout 7 days. MTA-Fillapex demonstrated the best performance among the calcium silicate-based sealers for the three fungal species (p < 0.05), maintaining stable values over the 7 days, surpassing that of Endomethasone. Nevertheless, MTA-Fillapex only exhibited antimicrobial effect against the mixed culture for the first 24 hours, and no antimicrobial activity was observed at 48 hours, being surpassed by all tested sealers (p < 0.05). Conclusion: Of all silicate-based sealers tested, only MTA-Fillapex exhibited promising antifungal activity. Nevertheless, care must be taken when extrapolating these results, as MTA-Fillapex exhibited poor antimicrobial activity when tested in mixed microbial cultures

Evaluation of the apical sealing of an eggshell hydroxyapatite-based sealer.

Background: The success of endodontic treatment can be influenced by the type of endodontic sealer used, as certain sealers may be prone to apical microleakage, leading to treatment failure. The limitations of currently available sealers necessitate the development of new materials to improve the success rate of endodontic treatment. Therefore, the objective of this study was to assess the apical microleakage of newly developed hydroxyapatite-based endodontic sealers, including one derived from eggshells, and compare them with other commercially available sealers. Material and Methods: Eighty-five extracted human upper anterior teeth were selected for this study. The teeth were divided into 5 experimental groups and 2 control groups. The experimental groups were designated as follows: (1) HPSINT - obturated with gutta-percha cone and synthetic hydroxyapatite-based sealer, (2) BIOC - obturated with gutta-percha cone and Bio C-Sealer sealer, (3) AHPLUS-BC - obturated with gutta-percha cone and AHPLUS Bioceramic sealer, (4) AHP - obturated with gutta-percha cone and AHPLUS sealer, and (5) HPO - obturated with gutta-percha cone and sealer based on hydroxyapatite extracted from eggshells. Additionally, there were positive and negative control groups consisting of instrumented teeth filled with gutta-percha cones without any sealer and instrumented teeth without any filling, respectively. Methylene blue dye penetration was used to assess apical microleakage. Descriptive statistical analysis and Shapiro-Wilk normality test were applied to the observed results. As the samples followed a normal distribution, the ANOVA test was applied. Results: The control groups confirmed the validity of the experimental method, while the experimental groups showed varying degrees of dye penetration. The group obturated with Bio C-Sealer exhibited the highest mean apical microleakage, while AHPLUS Bioceramic sealer demonstrated lower mean than AHPLUS sealer and sealer based on hydroxyapatite extracted from eggshells (p<0.05). Finally, there was no difference between the synthetic hydroxyapatite-based sealer and AHPLUS Bioceramic sealer, AHPLUS sealer and sealer based on hydroxyapatite extracted from eggshells (p>0.05). No significant difference was observed between the hydroxyapatite-based sealers and the AHPLUS-BC sealer. Conclusions: The results of this study suggest that the newly developed hydroxyapatite-based endodontic sealers, including the one derived from eggshells, may have a lower risk of apical microleakage compared to other commercially available sealers. These findings highlight the potential of hydroxyapatite-based sealers to improve the success rate of endodontic treatment. Further research and clinical studies are warranted to validate these results and explore the long-term effects of these novel sealers. Key words:Endodontic treatment, apical microleakage, endodontic sealer, hydroxyapatite, eggshell-derived sealer.

Analysis of antimicrobial efficacy of sodium hypochlorite and ozonated water against biofilm in oval canals.

This in vitro study compared the antimicrobial efficacy of 2.5% sodium hypochlorite (NaOCl) and 8 µg/mL ozonated water agitated by passive ultrasonic irrigation (PUI) or PUI combined with EndoActivator (EA) against mature multispecies biofilm. One hundred and five oval-shaped mandibular premolars were instrumented, sterilized, and inoculated with Enterococcus faecalis, Candida albicans, and Staphylococcus aureus, divided into: control group - saline; O3 group - ozonated water; O3 PUI group - ozonated water with PUI agitation; O3 PUI+EA group - ozonated water with PUI+EA agitation; NaOCl group - NaOCl; NaOCl PUI group - NaOCl with PUI agitation; and NaOCl PUI+EA group - NaOCl with PUI+EA agitation. Microbiological samples were collected before (S1) and after (S2) the disinfection procedures and the data were statistically analyzed using the Kruskal-Wallis test. In the culture method, there was significant disinfection in the O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). The combination of NaOCl with PUI+EA reduced microbial counts to zero (p˂0.05). In the qPCR method, there was a significant reduction in the total count of viable microorganisms in the O3 PUI, O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). It can be concluded that 2.5% NaOCl with and without agitation, as well as 8 µg/mL ozonated water with its action enhanced by the agitation techniques, were effective in root canal disinfection, and their antimicrobial efficacy is related to the microorganisms present in the biofilm.

Analysis of antimicrobial efficacy of sodium hypochlorite and ozonated water against biofilm in oval canals

Abstract This in vitro study compared the antimicrobial efficacy of 2.5% sodium hypochlorite (NaOCl) and 8 µg/mL ozonated water agitated by passive ultrasonic irrigation (PUI) or PUI combined with EndoActivator (EA) against mature multispecies biofilm. One hundred and five oval-shaped mandibular premolars were instrumented, sterilized, and inoculated with Enterococcus faecalis, Candida albicans, and Staphylococcus aureus, divided into: control group - saline; O3 group - ozonated water; O3 PUI group - ozonated water with PUI agitation; O3 PUI+EA group - ozonated water with PUI+EA agitation; NaOCl group - NaOCl; NaOCl PUI group - NaOCl with PUI agitation; and NaOCl PUI+EA group - NaOCl with PUI+EA agitation. Microbiological samples were collected before (S1) and after (S2) the disinfection procedures and the data were statistically analyzed using the Kruskal-Wallis test. In the culture method, there was significant disinfection in the O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). The combination of NaOCl with PUI+EA reduced microbial counts to zero (p˂0.05). In the qPCR method, there was a significant reduction in the total count of viable microorganisms in the O3 PUI, O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). It can be concluded that 2.5% NaOCl with and without agitation, as well as 8 µg/mL ozonated water with its action enhanced by the agitation techniques, were effective in root canal disinfection, and their antimicrobial efficacy is related to the microorganisms present in the biofilm.

Resumo Este estudo in vitro comparou a desinfecção do hipoclorito de sódio 2,5% (NaOCl) e da água ozonizada 8 µg/mL agitados pela irrigação ultrassônica passiva (PUI) e por associação da PUI com EndoActivator (EA) na redução de biofilme misto maduro. Cento e cinco pré-molares inferiores ovalados foram instrumentados, esterilizados e inoculados com Enterococcus faecalis, Candida albicans e Staphylococcus aureus, divididos em: Grupo controle: soro; Grupo O3: água ozonizada; Grupo O3 PUI: água ozonizada agitada por PUI; Grupo O3 PUI + EA: água ozonizada agitada por PUI e EA: Grupo NaOCl: hipoclorito de sódio; Grupo NaOCl PUI: hipoclorito de sódio agitado por PUI; Grupo NaOCl PUI + EA: hipoclorito de sódio agitado por PUI e EA. Amostras microbiológicas foram coletadas antes (S1) e após (S2) os procedimentos de desinfecção e os dados foram analisados estatisticamente pelo teste de Kruskal-Wallis. No método de cultura, houve desinfecção significativa nos grupos O3 PUI + EA, NaOCl, NaOCl PUI e NaOCl PUI + EA (p˂0.05), sendo que no grupo NaOCl PUI + EA não houve crescimento de microrganismo (p˂0.05). No método de qPCR, nas contagens dos microrganismos antes e após os protocolos de desinfecção, houve redução microbiana nos grupos O3 PUI, O3 PUI + EA, NaOCl, NaOCl PUI, NaOCl PUI + EA (p˂0.05). Concluiu-se que o NaOCl 2,5% com e sem agitação foi eficiente, assim como a água ozonizada 8 µg/mL potencializada pelos métodos de agitação na desinfecção e que a mesma está relacionada com os microrganismos presentes no biofilme.

Ex Vivo Evaluation of the Efficacy of Photodynamic Therapy in Eliminating Enterococcus faecalis from Dentinal Tubules by Confocal Laser Scanning Microscopy.

INTRODUCTION: The aim of the present study was to investigate ex vivo by confocal laser scanning microscopy the antibacterial effect of photodynamic therapy (PDT) on dentinal tubules in the apical 5 mm of human mandibular premolars contaminated with Enterococcus faecalis. METHODS: Thirty-four teeth were standardized to 20 mm and foraminal anatomic diameters using a #20 K-file (Dentsply Maillefer). Samples were contaminated for 21 days and divided into the following 3 experimental groups (n = 10): the PDT group (instrumented canals and PDT), the passive ultrasonic irrigation (PUI) group (instrumented canals and PUI), and the PUI-PDT group (instrumented canals, PUI, and PDT), along with a control group (n = 4) (noninstrumented canals). The canals in the experimental groups were instrumented with ProTaper Next (Dentsply Maillefer) up to X3 and rinsed with EDTA and sodium hypochlorite. The photosensitizer used was 0.01% methylene blue with a preirradiation time of 5 minutes and a diode laser with 4 J energy and a 660-nm wavelength. Cross sections were made 5 mm from the apex of all samples, which were analyzed using confocal laser scanning microscopy. The results were analyzed using the Shapiro-Wilk and Kruskal-Wallis (Dunn) tests. RESULTS: There was a lower percentage of live bacteria in the PUI-PDT group, with a statistical difference compared with the control and PDT groups (P < .05). There was no statistical difference in the percentage of live bacteria between PUI-PDT and PUI (P > .05). CONCLUSIONS: It was concluded that the PUI-PDT association was most effective in disinfecting root canals compared with the control group and PDT.

Effect of cone-beam computed tomography metal artefact reduction on incomplete subtle vertical root fractures.

Purpose: This study compared the accuracy of detection of incomplete vertical root fractures (VRFs) in filled and unfilled teeth on cone-beam computed tomography images with and without a metal artefact reduction (MAR) algorithm. Materials and Methods: Forty single-rooted maxillary premolars were selected and, after endodontic instrumentation, were categorized as unfilled teeth without fractures, filled teeth without fractures, unfilled teeth with fractures, or filled teeth with fractures. Each VRF was artificially created and confirmed by operative microscopy. The teeth were randomly arranged, and images were acquired with and without the MAR algorithm. The images were evaluated with OnDemand software (Cybermed Inc., Seoul, Korea). After training, 2 blinded observers each assessed the images for the presence and absence of VRFs 2 times separated by a 1-week interval. P-values<0.05 were considered to indicate significance. Results: Of the 4 protocols, unfilled teeth analysed with the MAR algorithm had the highest accuracy of incomplete VRF diagnosis (0.65), while unfilled teeth reviewed without MAR were associated with the least accurate diagnosis (0.55). With MAR, an unfilled tooth with an incomplete VRF was 4 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition, while without MAR, an unfilled tooth with an incomplete VRF was 2.28 times more likely to be identified as having an incomplete VRF than an unfilled tooth without this condition. Conclusion: The use of the MAR algorithm increased the diagnostic accuracy in the detection of incomplete VRF on images of unfilled teeth.

Micro- CT evaluation of sealers removal by reciprocal instrumentation followed by continuous ultrasonic irrigation in teeth with oval root canals.

Background: The ability of the Reciproc system (R40) followed by continuous ultrasonic irrigation (CUI) to remove filling material from oval root canals of mandibular premolars filled with gutta-percha and AH Plus or Bio-C Sealer was evaluated by microtomography (micro-CT). Material and Methods: The straight and oval root canals of 42 mandibular premolars were prepared with the ProDesign R 35.05 reciprocal file and randomly divided into two groups according to the material used to fill the canals (n=21): Group AH - Master Cone and AH Plus; Group BC - Master Cone and Bio-C Sealer. After filling and provisional sealing, the teeth were stored at 100% relative humidity and a temperature of 37°C for 30 days. The filling material was then removed with an R40 file. The material was considered completely removed when the R40 file reached the working length (WL), and no remaining filling material was visible on the canal walls. CUI was then performed. The teeth were scanned by micro- CT before and after removal of the filling material. The remaining filling material was measured in mm in the last apical 5 mm. The data were analyzed with the nonparametric Friedman test and subsequently with the Dunn test. The Mann-Whitney U test was also performed. Statistical significance was accepted at the 5% level. Results: After instrumentation with the Reciproc R40, the volume of residual filling material was significantly greater in the BC group than in the AH group (P = 0.035). After CUI, there was no difference in the volume of residual material between the two groups (P = 0.705). Conclusions: Bio-C sealer was more difficult to remove with the Reciproc file than AH Plus. CUI improved the removal of residual filling material regardless of sealer type. However, no technique was able to completely clear the canals of filling material. Key words:Bioceramic cement, CUI, micro-CT, reciproc, retreatment.

Comparative analysis of torsional and cyclic fatigue resistance of ProGlider, WaveOne Gold Glider, and TruNatomy Glider in simulated curved canal.

Objectives: This study aimed to compare the torsional and cyclic fatigue resistance of ProGlider (PG), WaveOne Gold Glider (WGG), and TruNatomy Glider (TNG). Materials and Methods: A total of 15 instruments of each glide path system (n = 15) were used for each test. A custom-made device simulating an angle of 90° and a radius of 5 millimeters was used to assess cyclic fatigue resistance, with calculation of number of cycles to failure. Torsional fatigue resistance was assessed by maximum torque and angle of rotation. Fractured instruments were examined by scanning electron microscopy (SEM). Data were analyzed with Shapiro-Wilk and Kruskal-Wallis tests, and the significance level was set at 5%. Results: The WGG group showed greater cyclic fatigue resistance than the PG and TNG groups (p < 0.05). In the torsional fatigue test, the TNG group showed a higher angle of rotation, followed by the PG and WGG groups (p < 0.05). The TNG group was superior to the PG group in torsional resistance (p < 0.05). SEM analysis revealed ductile morphology, typical of the 2 fracture modes: cyclic fatigue and torsional fatigue. Conclusions: Reciprocating WGG instruments showed greater cyclic fatigue resistance, while TNG instruments were better in torsional fatigue resistance. The significance of these findings lies in the identification of the instruments' clinical applicability to guide the choice of the most appropriate instrument and enable the clinician to provide a more predictable glide path preparation.

Effect of different activation methods on the intratubular penetration of CaOH2 paste: Ex-vivo analysis by confocal laser scanning microscopy.

The aim of this study was to evaluate the maximum penetration depth (MPD) and penetration area (PA) of CaOH2 paste agitated by different methods and to measure the pH after performing these methods. Fifty-five mandibular premolars were divided into control, GL and 4 experimental groups, GEC, GXP, GEDDY and GI (n = 11), where the paste was agitated with Easy Clean, XP-endo Finisher, EDDY and Irrisonic, respectively. The canals were instrumented and irrigated with NaOCl. The paste was manipulated with propylene glycol and rhodamine B dye. Root sections were examined using confocal laser scanning microscopy. There was no difference between groups regarding PA (p > 0.05). At 5 mm, MPD was greater in GEC than in GL or GEDDY, and greater in GI than in GL (p < 0.05). At 2 mm, MPD was greater in GEC than in the other groups (p < 0.05). In conclusion, both Easy Clean and Irrisonic promoted deeper paste penetration and were associated with higher pH levels.

Influence of Heat Treatment of Nickel-Titanium Instruments on Cyclic Fatigue Resistance in Simulated Curved Canals.

OBJECTIVE: The aim of this study was to compare the cyclic fatigue of heat-treated and non-treated instruments. MATERIALS AND METHODS: Twenty instruments with and without heat treatment from Bassi Logic were evaluated (n = 10). All instruments were subjected to dynamic cyclic fatigue through continuous rotations inside a stainless-steel tube (1.4-mm diameter, 9-mm curvature with 6-mm radius, and 90° angle) using a custom-made device, which performed 1 axial oscillation every 2 seconds with an amplitude of 3 mm, powered by a torque-controlled motor (Silver Reciproc, VDW, Germany), with speed adjusting to 950 rpm and torque to 4 N, according to manufacturer's guidance. The groups were compared using the Mann-Whitney test. RESULT: The fracture time of the heat-treated instruments (97.20 ± 39.94 second and non-treated instruments (14.30 ± 6.78 seconds had statistical differences [p < 0.05]). Heat-treated instruments were 6.8 times more resistant to fatigue than non-treated instruments (p < 0.05). CONCLUSION: Heat treatment provides increased fatigue resistance of NiTi alloy with the same design.

Microtomographic Assessment of the Shaping Ability of the Hyflex CM and XP-endo Shaper Systems in Curved Root Canals.

OBJECTIVE: This study compared the shaping ability of the Hyflex CM and XP-endo Shaper rotary file systems in curved mesial canals of mandibular molars using micro-computed tomography. MATERIAL AND METHODS: Seventeen mesial roots of extracted first mandibular molars with two independent mesial canals were scanned before and after root canal preparation with the tested rotatory file systems. Each mesial canal from the same specimen was prepared with one of the two systems. The parameters analyzed were canal centering (transportation) for the cervical, middle, and apical segments, as well as for the entire canal (0-10 mm from the apex); and canal volume increase, canal surface area increase, and unprepared canal walls for two segments, 0 to 4 mm and 0 to 10 mm from the apex. RESULTS: There was no significant difference between both systems regarding canal centering (transportation), volume increase, and unprepared canal walls for the 0 to 10 mm segment (p> 0.05); however, a significant difference was observed for the 0 to 4 mm segment (p <0.01), where the Hyflex CM left 28.46% of unprepared walls and XP-endo Shaper left 13.26%. CONCLUSIONS: The shaping ability of the two tested rotatory file systems in mesial roots of first mandibular molars was similar for all parameters in all the segments evaluated, except for the 0 to 4 mm segment, where XP-endo Shaper left a smaller area of unprepared canal walls than Hyflex CM.

Influência do hipoclorito de sódio na resistência à fadiga cíclica em instrumentos rotatórios endodônticos de memória controlada de NiTi: uma avaliação experimental / Influence of sodium hypochlorite on cyclic fatigue resistance in niti controlled memory endodontics rotary instruments: an experimental evaluation

Introdução: É importante saber se o hipoclorito de sódio (NaOCl) influencia a resistência à fadiga cíclica das limas de níquel-titânio (NiTi). Objetivo: Avaliar a influência de NaOCl 2,5% na resistência à fadiga cíclica de dois sistemas de NiTi. Material e método: 40 instrumentos rotatórios - 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Suíça) e 20 Prodesing Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brasil) - foram aleatoriamente distribuídos em 4 grupos experimentais (n = 10) imersos em água destilada (H2O) e NaOCl 2,5% em temperatura a 37°C. Foram submetidos a testes de fadiga cíclica mensurando o número de ciclos para fratura (NCF) e análise dessas superfícies pós-teste em microscópio eletrônico por varredura. Para a análise estatística entre os grupos, foi aplicada a análise de variância (ANOVA), complementada com o pós-teste de Tukey. Resultado: Houve diferença estatística em todos os grupos (P<0.05). Os instrumentos PDL2 obtiveram maior resistência à fratura nas condições em H2O e em NaOCl 2,5% comparados aos instrumentos TRU. Na análise de grupos de instrumentos nas soluções de NaOCl e H2O, foi observado que o NaOCl 2,5% diminuiu o NCF. Conclusão: A resistência à fadiga cíclica dos instrumentos TRU e PDL2 diminuiu com NaOCl 2,5%. Os instrumentos PDL2 foram mais resistentes à fratura em relação aos instrumentos TRU.

Introduction: It is important to know whether sodium hypochlorite (NaOCl) influences the cyclic fatigue resistance of nickel-titanium (NiTi) files. Objective: To evaluate the influence of NaOCl 2.5% on the cyclic fatigue resistance of two NiTi systems. Material and method: Forty rotary instruments - 20 TruNatomy® (TRU, Dentsply Sirona, Maillefer, Ballaigues, Switzerland) and 20 Prodesign Logic2® (PDL2, Bassi, Belo Horizonte, Minas Gerais, Brazil) - were distributed randomly across four experimental groups (n=10) and submerged in distilled water (H2O) or 2.5% NaOCl at 37°C according to allocation. Cyclic fatigue testing was then performed, measuring the number of cycles to fracture (NCF), and post-test surfaces were analysed by scanning electron microscopy (SEM). Statistical Analysis: Analysis of variance (ANOVA) was applied for between-group analysis, followed by Tukey's post-hoc test. Result: A significant difference was observed in all groups (P<0.05). PDL2 instruments showed higher fracture resistance under H2O and 2.5% NaOCl conditions compared to TRU. Analysis of all instrument groups showed that exposure to 2.5% NaOCl decreased the NCF compared to H2O. Conclusion: Cyclic fatigue resistance of the TRU and PDL2 instruments was decreased by exposure to 2.5% NaOCl. PDL2 instruments were more resistant to fracture than TRU instruments.

Fracture incidence of Reciproc instruments during root canal retreatment performed by postgraduate students: a cross-sectional retrospective clinical study.

OBJECTIVES: To evaluate the fracture incidence of Reciproc R25 instruments (VDW) used during non-surgical root canal retreatments performed by students in a postgraduate endodontic program. MATERIALS AND METHODS: From the analysis of clinical record cards and periapical radiographs of root canal retreatments performed by postgraduate students using the Reciproc R25, a total of 1,016 teeth (2,544 root canals) were selected. The instruments were discarded after a single use. The general incidence of instrument fractures and its frequency was analyzed considering the group of teeth and the root thirds where the fractures occurred. Statistical analysis was performed using the χ2 test (p < 0.01). RESULTS: Seven instruments were separated during the procedures. The percentage of fracture in relation to the number of instrumented canals was 0.27% and 0.68% in relation to the number of instrumented teeth. Four fractures occurred in maxillary molars, 1 in a mandibular molar, 1 in a mandibular premolar and 1 in a maxillary incisor. A greater number of fractures was observed in molars when compared with the number of fractures observed in the other dental groups (p < 0.01). Considering all of the instrument fractures, 71.43% were located in the apical third and 28.57% in the middle third (p < 0.01). One instrument fragment was removed, one bypassed, while in 5 cases, the instrument fragment remained inside the root canal. CONCLUSIONS: The use of Reciproc R25 instruments in root canal retreatments carried out by postgraduate students was associated with a low incidence of fractures.

Avaliação do número de canais radiculares de incisivos inferiores usando tomografia computadorizada de feixe cônico / Evaluation of the number of root canals of mandibular incisors using cone beam computed tomography

Introdução: O estudo da anatomia da raiz e do canal radicular tem importância relevante para o tratamento endodôntico. Portanto, o conhecimento da morfologia do canal radicular é essencial para se realizar um tratamento que resulte em sucesso. No entanto, o profissional tem limitada informação desses conhecimentos, e um acesso difícil ao local de atuação. Objetivo: O presente estudo teve por objetivo avaliar o número de canais de incisivos inferiores, visto que estudos realizados sobre o assunto apresentam uma alta taxa de incisivos inferiores com dois canais radiculares. Métodos: Para avaliar com detalhes a anatomia interna das raízes dos incisivos inferiores, foi utilizada a tomografia computadorizada de feixe cônico (TCFC) na observação dos canais radiculares, em dentes permanentes humanos. Foram analisadas 97 imagens tomográficas obtidas com um tomógrafo Orthopantomograph OP 300 (Instrumentarium, Tuusula, Finlândia) de pacientes que se submeteram ao exame por motivos diversos. Todos os grupos dentários foram avaliados individualmente, e sua morfologia interna foi determinada conforme a Classificação de Vertucci (1984). Resultados: Os resultados observados por meio do teste estatístico do qui-quadrado apresentaram maior frequência dos Tipos I e III (Classificação de Vertucci), em comparação aos outros tipos (p<0,001). Conclusão: Conclui-se que a TCFC é o recurso viável para auxiliar a prática endodôntica, especialmente em casos complexos, como a localização de canais radiculares. A ocorrência de mais de um canal em incisivos inferiores centrais e laterais foi de 23,71% nesse estudo realizado na população brasileira (AU).

Introduction: The study of root and rood canal anatomy is relevant for endodontic treatment. Therefore, knowledge of the root canal morphology is essential to achieve an end- odontic that results in success. However, the professional has limited information of this knowledge and difficult access to the place of performance. Objective: The present study aimed to evaluate the number of the canals of the mandibular incisors, since studies carried out on the subject present a high rate of mandibular incisors with two canals. Methods: In order to evaluate in detail the internal anatomy of the roots of incisors, the accuracy of the cone beam computed tomography in the observation of the root canals in human permanent teeth was evidenced in this study. We analized 97 tomographic images obtained using ORTHO-PANTOMOGRAPH OP 300 (Instrumentarium, Tuusula, FI) of patients who underwent the diagnostic procedure for several reasons. All dental groups were analyzed individually and the morphology was determined according Vertucci Classification (1984). Results: The results observed the Chi-Square statistical test presented higher frequency of Types I and III (Vertucci Criterion) in relation to the other types (p<0.001). Conclusion: It was concluded that computed tomography is the viable resource to aid endodontic practice, especially in complex cases, such as the location of the root canals. The occurrence of more than one canal in central and lateral lower incisors was 23,71% in this study performed in the Brazilian population (AU).

Influence of apical preparation size and final irrigation protocol on the debridement of oval root canals

Abstract This study assessed the influence of apical preparation size and final irrigation protocol on the debridement of the apical third of oval root canals of mandibular molars. Seventy-seven distal roots were divided into 7 groups (n = 11): Control: without instrumentation or irrigation; Group 30CI: ProTaper Next (up to size 30; PTN) + conventional irrigation (CI); Group 30UAI: PTN + ultrasonically activated irrigation (UAI); Group 30XPF: PTN + XP-endo Finisher (XPF); Group 40CI: PTN + ProDesign Logic (up to size 40; PDL) + CI; Group 40UAI: PTN + PDL + UAI; and Group 40XPF: PTN + PDL + XPF. The total volume of irrigating solutions used per root canal in all the experimental groups was 33 mL of 2.5% sodium hypochlorite (NaOCl) and 6 mL of 17% ethylenediaminetetraacetic acid (EDTA). After specimen processing and histological analysis under a digital microscope (100x), the percentages of untouched canal walls (UCW) and remaining debris (RD) were assessed using Image J software. A descriptive and exploratory analysis was conducted, indicating that the data failed to meet the assumptions of an analysis of variance. Therefore, generalized linear models were used to assess the effects of the different instrumentation and irrigation protocols, as well as the interaction among them, on the percentage of UCW and RD. No significant difference was found among the irrigation protocols regarding the percentage of UCW, irrespective of apical preparation size (p>0.05). However, UCW and RD were significantly lower in groups 40CI, 40UAI and 40XPF than in groups 30CI, 30UAI and 30XPF (p<0.05). The percentage of RD was significantly lower in the UAI and XPF groups than in the CI groups, irrespective of apical preparation size (p<0.05). The difference between preparation sizes 30 and 40, with respect to RD, was higher when CI was used (p<0.05). In conclusion, instrumentation up to apical preparation size 40 resulted in lower percentages of UCW and RD than up to apical preparation size 30. Use of UAI or XPF resulted in lower percentages of RD than CI.

Resumo Este estudo avaliou a influência do tamanho do preparo apical e do protocolo de irrigação final sobre o debridamento do terço apical de canais radiculares ovais de molares inferiores. Setenta e sete raízes distais foram selecionadas e divididas em 7 grupos (n = 11): Grupo controle: sem instrumentação nem irrigação; Grupo 30IC, ProTaper Next (até o tamanho 30; PTN) + irrigação convencional (IC); Grupo 30IAU, PTN + irrigação ativada ultrassonicamente (IAU); Grupo 30XPF, PTN + XP-endo Finisher (XPF); Grupo 40IC, PTN + ProDesign Logic (até o tamanho 40; PDL) + IC; Grupo 40IAU, PTN + PDL + IAU; e Grupo 40XPF, PTN + PDL + XPF. Os volumes totais dos irrigantes utilizados por canal radicular em todos os grupos experimentais foram 33 mL de hipoclorito de sódio (NaOCl) a 2,5% e 6 mL de ácido etilenodiamino tetracético (EDTA) a 17%. Após o processamento dos espécimes e a análise das secções histológicas sob um microscópio digital (100x), as porcentagens de paredes não instrumentadas (PNI) e detritos remanescentes (DR) foram avaliadas utilizando-se o software Image J. Uma análise descritiva e exploratória foi realizada, indicando que os dados não atenderam aos pressupostos de uma análise de variância. Modelos lineares generalizados foram, portanto, utilizados para avaliar os efeitos dos diferentes protocolos de instrumentação e irrigação, bem como da interação entre eles, sobre as porcentagens de PNI e DR. Não houve diferença significativa entre os protocolos de irrigação final quanto à porcentagem de PNI, independentemente do tamanho do preparo apical (p>0,05). Entretanto, as porcentagens de PNI e DR foram significativamente menores nos grupos 40IC, 40IAU e 40XPF do que nos grupos 30IC, 30IAU e 30XPF (p<0,05). A porcentagem de DR foi significativamente menor nos grupos em que se utilizou a IAU ou o XPF do que naqueles em que se utilizou a IC, independentemente do tamanho do preparo apical (p<0,05). A diferença entre os tamanhos de preparo apical 30 e 40 com relação aos DR foi maior quando se utilizou a IC (p<0,05). Concluiu-se que a instrumentação até um preparo apical de tamanho 40 resultou em menores porcentagens de PNI e DR do que até um preparo apical de tamanho 30. A utilização da IAU ou do XPF resultou em uma menor porcentagem de DR do que a utilização da IC.

Effect of Foraminal Enlargement on Postoperative Pain in Necrotic Single-Rooted Teeth: A Randomized Clinical Trial.

INTRODUCTION: The aim of this study was to evaluate pain perception, pain medication intake, and sealer extrusion after single-visit root canal treatment of asymptomatic teeth with or without foraminal enlargement. The correlation between sealer extrusion and pain was also investigated. METHODS: One hundred forty necrotic, single-rooted teeth were divided into 2 groups (n = 70): foraminal patency (FP), in which treatment was performed up to 1 mm short of the apex, and foraminal enlargement (FE), in which treatment was performed up to the apex. The canals were instrumented using WaveOne Gold files (Dentsply Maillefer, Ballaigues, Switzerland), irrigated with 2.5% sodium hypochlorite, and filled using the single-cone technique and AH Plus sealer (Dentsply Maillefer). A visual analog scale was used to record pain 24, 48, and 72 hours and 1 week postoperatively. The presence or absence of sealer extrusion was recorded. RESULTS: Pain levels were significantly higher for FE than FP at 24 hours (P < .05), namely 0.3 ± 0.9 versus 0.1 ± 0.1; no difference was found at 48 hours, namely 0.1 ± 0.5 versus 0.0 ± 0.0 (P > .05). No pain was reported 72 hours or 1 week postoperatively in either group. Although all patients requiring pain medication at 24 hours were from the FE group, the difference between FE and FP was not statistically significant with respect to this variable (P > .05). Nevertheless, the intake amount was significantly higher in FE than in FP at this time point (P < .05). Sealer extrusion occurred more frequently in FE than FP, namely 57.14 % versus 14.29% (P < .05). There was no association between pain and sealer extrusion (P > .05) or between pain and sex, age, or tooth type (P > .05). CONCLUSION: FE was related to higher pain levels 24 hours postoperatively and to higher rates of filling material extrusion; however, there was no association between filling material extrusion and postoperative pain.

Aspectos técnicos dos tratamentos endodônticos realizados por cirurgiões-dentistas da PMESP: avaliação por meio de questionário / Technical aspects of endodontic treatments performed by PMESP dentists: evaluation by means of a questionnaire

Introdução: De todas as especialidades na Odontologia, uma das mais favorecidas nos últimos anos com o desenvolvimento de novas tecnologias tem sido a Endodontia. Objetivo: O presente estudo visou obter informações sobre os aspectos técnicos dos tratamentos endodônticos realizados por cirurgiões-dentistas da Polícia Militar do Estado de São Paulo (PMESP), dando ênfase aos materiais, técnicas e equipamentos empregados. Métodos: Um questionário com 25 questões de múltipla escolha foi enviado aos 147 dentistas da PMESP, e o critério de inclusão foi que os profissionais realizassem tratamentos endodônticos. Resultados: A análise estatística foi feita por meio do teste qui-quadrado, com p<0,05. Entre os 42 profissionais avaliados, 59,5% eram do sexo masculino, o dique de borracha foi utilizado em 54,8% dos casos, o comprimento de trabalho foi obtido por meio de radiografias em 71,4%, o sensor digital foi utilizado em 28,6%, a magnificação visual foi utilizada em 23,8% e a técnica de condensação lateral foi a mais utilizada, com 90,2%. Outra análise foi realizada com 10 especialistas do Centro Odontológico da PMESP que efetuavam unicamente tratamento endodôntico, sendo que 50% eram do sexo masculino e tratavam mais de 15 casos/mês: o dique de borracha foi utilizado em 80% dos casos; o comprimento de trabalho foi obtido com localizador foraminal em 50% dos casos; o sensor digital foi utilizado em 90%, assim como o motor elétrico; a técnica de condensação lateral foi utilizada em 60% dos casos e o ultrassom, em 20%. Conclusões: Conclui-se que os especialistas utilizaram mais as novas tecnologias, e que o ultrassom e a magnificação visual foram pouco utilizados em ambos os grupos (AU).

Introduction: Of all the specialties in dentistry, one of the most favored in recent years with the development of new technologies has been endodontics. Objective: This study aimed to obtain information on the technical aspects of endodontic treatments performed by dentists from the Military Police of the State of São Paulo, emphasizing the materials, equipment, and techniques used. Methods: A questionnaire with 25 multiple choice questions was sent to 147 dentists from PMESP and the inclusion criterion was professionals who performed endodontic treatment. Results: The statistical analysis was done through the chi-square test, with p< 0.05. The professionals evaluated 59.5% were male, the rubber dam was used in 54.8% of the cases, the working length by means of radiographs was obtained in 71.4%, the digital sensor was used in 28.6%, the visual magnification was used in 23.8% and the lateral condensation technique was the most used with 90.2%. Another analysis was performed with 10 specialists of the Dental Center who performed only endodontic treatment, 50% were male, treated more than 15 cases/month, the rubber dike was used in 80% of the cases, the working length was performed in 50% of the cases by foraminal locator, the digital sensor was used in 90%, as well as the electric motor, the technique of lateral condensation was used in 60% of the cases and ultrasound 20%. Conclusion: It was concluded that the specialists used more new technologies and that the use of ultrasound and visual magnification was little used in both groups (AU).

The ability of reciprocating glide path instruments to reach the full root canal working length.

This study evaluated the ability of reciprocating glide path instruments to reach the full working length (RFWL). Thirty mesial roots of mandibular molars were matched into 2 groups (n = 15 teeth, 30 root canals), according to the system used for glide path: WaveOne Gold Glider (WOGG) and R-Pilot. The samples with fractured instruments or when it was not possible to RFWL were scanned using micro-computed tomography. Fractured instruments were also visualised through a scanning electron microscopy to verify the type of fracture. The parameters were compared statistically by Fisher's and chi-square tests (P < 0.05). No instrument fractures were observed in the R-pilot, while 2 fractures occurred in the WOGG group (P > 0.05). RFLW was achieved in 29 canals (96.66%) and 28 canals (93.33%) with R-pilot and WOGG instruments, respectively (P > 0.05). The instruments are able to RFWL in mesial canals of mandibular molars. WOGG showed two fractures while no R-Pilot instruments fractured.