Influence of the use of chelating agents as final irrigant on the push-out bond strength of epoxy resin-based root canal sealers: A systematic review.

This systematic review (PROSPERO - CRD42020150722) was performed to answer the following question: Does the use of chelating agents affect the dislodgment resistance of epoxy resin-based root canal sealers? A search was conducted in PubMed, EMBASE, Scopus, LILACS and Web of Science, hand searching of two endodontic journals and grey literature until September 2020. Extracted data included: teeth used, sample size, root canal preparation, irrigant, chelating solution, neutralisation solution, type of resin-based sealer and obturation approach, storage method and duration, root third and slice thickness, plunger dimension and loading direction and the push-out testing parameters and values. The search retrieved a total of 2.389 studies. After analysis, 12 studies fulfilled the eligibility criteria and were included. Most of the final irrigation protocols with chelating agents had a positive impact and promoted an improvement in the dislodgment resistance of epoxy resin-based sealers to the root dentin.

Bacterial Reduction in Oval-Shaped Root Canals After Different Irrigant Agitation Methods.

OBJECTIVE: This study aimed to assess the antibacterial effect of Easy Clean®, passive ultrasonic irrigation and sonic irrigation against Enterococcus faecalis biofilm in oval-shaped canals. METHODS: Fifty-five extracted human teeth with similar dimensions were selected. Access cavities were prepared and the root canals were instrumented using Wave One® Primary files (25.08). The root canals were then contaminated with an E. faecalis suspension following incubation for thirty days. The contaminated roots were divided into three experimental groups (n=15) according to the irrigant agitation protocol (Easy Clean, passive ultrassonic irrigation and sonic irrigation), in addition to a positive control group (n=5) and a negative control group (n=5). Microbiological samples were taken from the root canals before instrumentation (S1), after instrumentation (S2) and after the final irrigation protocol (S3). The samples were assayed and incubated for 48 hours in order to obtain the residual titer of E. faecalis cells. Viable cells were quantified by colony-forming units (CFU) measurement. The collected data was submitted to statistical analysis by using Shapiro-Wilk`s test, Wilcoxon paired test, Kruskal-Wallis test and Dunn's post-hoc test. The level of significance was set at 5%. RESULTS: All experimental groups presented significant reduction on bacterial load after instrumentation (P<0.05) with similar reduction among the groups. After the agitation protocols, significant reduction in bacterial load was demonstrated for all groups (P<0.05). However, no differences were shown among Easy Clean®, PUI and SI (P>0.05). CONCLUSION: The results showed that all tested groups exhibited similar disinfection effectiveness. However, none of them was able to render all root canals free from microorganisms.

Physicochemical, cytotoxicity and in vivo biocompatibility of a high-plasticity calcium-silicate based material.

The purpose of this work was to evaluate the physicochemical properties, the cytotoxicity and in vivo biocompatibility of MTA Repair HP (MTA HP) and White MTA (WMTA). The setting time, flow, radiopacity and water solubility were assessed. To the cytotoxicity assay, primary human osteoblast cells were exposed to several dilutions of both materials eluates. MTT assay, apoptosis assay and cell adhesion assay were performed. The in vivo biocompatibility was evaluated through histological analysis using different staining techniques. No differences were observed between MTA HP and WMTA for setting time, radiopacity, solubility and water absorption (P > 0.05). However, MTA HP showed a significantly higher flow when compared to WMTA (P < 0.05). Cell viability results revealed that the extracts of WMTA and MTA HP promoted the viability of osteoblasts. After incubation of cells with the endodontic cement extracts, the percentage of apoptotic or necrotic cells was very low (<3%). Furthermore, SEM results showed a high degree of cell proliferation and adhesion on both groups. MTA HP showed similar in vivo biocompatibility to the WMTA and the control group in all time-points. The MTA HP presented adequate physicochemical and biological properties with improved flow ability when compared to WMTA. Such improved flow ability may be a result of the addition of a plasticizing agent and should be related to an improvement in the handling of MTA HP.

Ability of two single-step restorative materials to avoid crown darkening caused by intracanal minocycline paste.

OBJECTIVES: This study aimed to quantitatively assess the ability of two single-step restorative materials to avoid crown darkening caused by the use of minocycline as an intracanal medicament. MATERIALS AND METHODS: After coronal access and instrumentation, 120 maxillary incisors were divided into four groups (n = 30). Two experimental groups according to the restorative material applied to the inner walls of the access cavity: OB, OptiBond All-In-One + minocycline intracanal paste; U200, RelyX U200 + minocycline intracanal paste. Two control groups without restorative materials: MIN, minocycline intracanal paste and SL, saline intracanal. Color determination was performed using a spectrophotometer at five time points, immediately after materials were applied (baseline), and at 7, 14, 21, and 28 days from the baseline. RESULTS: Decrease in the mean values of L* (luminosity) was observed after insertion of minocycline paste in all groups at all time points. Statistically significant differences were absent between the time points (P > .05). After 28 days, MIN showed significantly more darkening (ΔL*) (- 10.6 ± 7.3) than OB (- 5.4 ± 6.2), U200 (- 5.8 ± 3.9) and SL (- 2.3 ± 1.2) (P < .05). CONCLUSIONS: Crown darkening can be minimized by the previous application of RelyX U200 or OptiBond All-In-One to the inner walls of the access cavity before a minocycline-containing paste is applied as an intracanal medication. CLINICAL RELEVANCE: The American Association of Endodontists Clinical Considerations for Regenerative Procedures in necrotic immature teeth suggests the triple antibiotic paste as an intracanal medication (2018). However, discoloration and crown darkening are common unfavorable outcomes. The clinical protocol suggested in this paper has shown to be able to minimize crown darkening, predictably leading to a better patient-centered clinical success.

Influence of Apical Preparation Size and Working Length on Debris Extrusion.

The aim of this study was to quantitatively evaluate the amount of apically extruded debris by single-file reciprocating instruments with different working lengths and apical preparation sizes. Eighty human single-rooted mandibular incisors were used and conventional access cavities were prepared. Then, the specimens were divided into four groups (n=20), according to root canal instrumentation: Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used at the foramen; Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used 1 mm short of the foramen. Distilled water was used as an irrigant and the apically extruded debris were collected in pre-weighted glass vials and dried afterwards. The mean weight of debris was weighed with a microbalance and statistically analyzed using one-way analysis of variance and the post hoc Tukey multiple comparison test (p<0.05). The results showed that all experimental groups were associated with debris extrusion. No significant difference was found in the amount of apically extruded debris among all experimental groups (p>0.05). The present study demonstrated that the working length and the apical preparation size did not have a significant effect on debris extrusion when performing single-file reciprocating instrumentation.

Influence of Apical Preparation Size and Working Length on Debris Extrusion

Abstract The aim of this study was to quantitatively evaluate the amount of apically extruded debris by single-file reciprocating instruments with different working lengths and apical preparation sizes. Eighty human single-rooted mandibular incisors were used and conventional access cavities were prepared. Then, the specimens were divided into four groups (n=20), according to root canal instrumentation: Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used at the foramen; Reciproc size 25, .08 taper and Reciproc size 40, .06 taper instruments were used 1 mm short of the foramen. Distilled water was used as an irrigant and the apically extruded debris were collected in pre-weighted glass vials and dried afterwards. The mean weight of debris was weighed with a microbalance and statistically analyzed using one-way analysis of variance and the post hoc Tukey multiple comparison test (p<0.05). The results showed that all experimental groups were associated with debris extrusion. No significant difference was found in the amount of apically extruded debris among all experimental groups (p>0.05). The present study demonstrated that the working length and the apical preparation size did not have a significant effect on debris extrusion when performing single-file reciprocating instrumentation.

Resumo Este estudo avaliou quantitativamente a quantidade de material extruído apicalmente pela instrumentação com lima única reciprocante, aplicando diferentes comprimentos de trabalho e tamanhos de preparo apical. Para a análise de extrusão foram utilizados oitenta incisivos inferiores unirradiculares humanos. Cavidades de acesso convencionais foram preparadas e os espécimes foram divididos em quatro grupos (n=20), de acordo com o tipo de instrumentação do canal: Reciproc 25, 0.08 e Reciproc 40, 0.06 foram utilizadas na instrumentação até o forame; Reciproc tamanho 25, 0.08 e Reciproc 40, 0,06 foram utilizadas na instrumentação até 1 mm aquém do forame. Água destilada foi empregada como irrigante e o material extruído apicalmente foi coletado em frascos de vidro já pesados e posteriormente submetidos a secagem. O peso médio de detritos foi avaliado com uma microbalança de precisão e os dados submetidos a ANOVA e teste Tukey (p<0,05). Todos os grupos experimentais foram associados à extrusão de debris. Nenhuma diferença significativa foi encontrada na quantidade de material extruído apicalmente entre os grupos (p>0,05). Este estudo demonstrou que o comprimento de trabalho e o tamanho do preparo apical não geraram efeito significativo sobre a extrusão de debris durante a instrumentação reciprocante.

Revascularization Technique for the Treatment of External Inflammatory Root Resorption: A Report of 3 Cases.

The current external inflammatory root resorption treatment protocol, which uses calcium hydroxide dressing, usually comprises multiple and long-term applications. In addition to the need for multiple appointments for calcium hydroxide replacement, the long-term maintenance of this compound in the root canal weakens dental structures. A modification of this therapy would be advisable. In this clinical investigation, 3 patients with external inflammatory root resorption were submitted to revascularization therapy protocol usually used in teeth with necrotic pulp and open apices. The teeth were treated with revascularization therapy protocol, which consisted of disinfecting the root canal system with triantibiotic paste, filling it with blood clot, and sealing of the root canal with mineral trioxide aggregate and bonded resin restoration. During the follow-up, the pathologic process was arrested with tissue repair in pre-existing radiolucent areas. Reduced mobility was observed in the treated teeth. The 3 cases were followed up for 30, 18, and 15 months, respectively. All teeth remained asymptomatic and retained function and physiological mobility. The therapy used in the revascularization procedure was efficient in the treatment of external inflammatory root resorption, reducing the number of appointments and increasing patient compliance.

A microbiological profile of unexposed and exposed pulp space of primary endodontic infections by checkerboard DNA-DNA hybridization.

INTRODUCTION: The aim of this study was to evaluate, by checkerboard DNA-DNA hybridization, the composition of the microbiota of primary endodontic infections in cases associated with exposed (n = 30) and unexposed (n = 30) pulp space. METHODS: Samples were collected by means of a #15 H-type file and 2 sterile paper points from 60 single-rooted teeth with necrotic pulp and periapical lesions. The presence, levels, and proportions of 40 bacterial species were determined by checkerboard DNA-DNA hybridization. RESULTS: The species found in higher counts (×10(5)) in exposed pulp space cases were Eubacterium saburreum, Fusobacterium nucleatum ssp. vincentii, Tannerella forsythia, Enterococcus faecalis, Neisseria mucosa, Campylobacter gracilis, and Prevotella nigrescens, and in unexposed pulp space cases they were F. nucleatum ssp. vincentii, N. mucosa, E. faecalis, E. saburreum, C. gracilis, and Porphyromonas gingivalis. Counts of F. nucleatum ssp. vincentii, Campylobacter sputigena, Capnocytophaga showae, Treponema socrenskii, Porphyromonas endodontalis, Eikenella corrodens, and Capnocytophaga ochracea were significantly higher in unexposed pulp space cases (P < .05). CONCLUSIONS: The data of the present investigation suggested specific differences between the composition of the microbiota in cases with exposed and unexposed pulp space and an association between higher levels of some specific species and unexposed pulp space cases.

A microbiological profile of symptomatic teeth with primary endodontic infections.

The aim of this study was to evaluate the composition of the microbiota of primary endodontic infections associated with symptomatic teeth. Samples were collected by means of a #15 H-type file and 2 sterile paper points from 60 symptomatic (n = 30) or asymptomatic (n = 30) single-rooted teeth with necrotic pulp. The presence of 40 bacterial species was determined by the checkerboard DNA-DNA hybridization method. The species found in higher counts (x10(5)) in symptomatic cases were Fusobacterium nucleatum ssp. vincentii, Veillonella parvula, Treponema socranskii, Enterococcus faecalis, and Campylobacter gracilis and in asymptomatic cases were F. nucleatum ssp. vincentii, Fusobacterium nucleatum ssp. nucleatum, E. faecalis, Eubacterium saburreum, and Neisseria mucosa. Total bacterial counts and counts of Tannerella forsythia were significant higher in symptomatic cases (p < 0.05), whereas levels of Propionibacterium acnes were reduced in this group of teeth. The data of the present investigation suggested an association between higher total bacterial counts and levels of T. forsythia and the presence of pain.

Antimicrobial activity of sodium hypochlorite and chlorhexidine by two different tests.

The aim of this study was to evaluate the antimicrobial capacity of sodium hypochlorite (1% and 5%) and chlorhexidine (0.12%, 0.5% and 1%) with or without the addition of organic material (bovine serum albumin, BSA) against some bacterial samples (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Porphyromonas gingivalis and Fusobacterium nucleatum) using two activity tests (contact and diffusion agar tests). In the contact test (first model), bacterial samples were kept in contact with each irrigating solution for different time intervals: immediately (t(0)), 5 min (t(5)), 15 min (t(15)) and 30 min (t(30)). The agar diffusion test was the second model used. In half the specimens, 0.5% BSA was added to simulate organic tissue present in the root canal. Bacterial growth was evaluated for each microorganism and activity test. Each test was repeated 10 times. In the contact test, 0.12% chlorhexidine solution (CHX) did not eliminate E. faecalis at any tested time. CHX at 0.5% eliminated all strains except E. faecalis after immediate contact. All strains were eliminated by 1% CHX, 1% NaOCl and 5% NaOCl. BSA did not interfere with the antimicrobial activity of the irrigating solutions. In the agar diffusion test, all solutions exhibited zones of antimicrobial activity; however, BSA interfered with the antimicrobial activity of NaOCl and CHX. Under the condition of the contact test, the 0.12% CHX was ineffective in eliminating E. faecalis, while 0.5% CHX, 1% CHX, 1% NaOCl and 5% NaOCl showed antibacterial effectiveness against all the tested bacterial strains. The addition of an organic load interfered with the accuracy of the agar diffusion test.