Evaluation of the rotary kinematics between actual and set speeds of X-Smart Plus, VDW.Silver and iRoot motors

Abstract The present study evaluated the actual rotational speed of three different endodontic motors compared to the values provided by the manufacturers. A total of three endodontic motors (X-Smart Plus, VDW.Silver, and iRoot) were tested at 400 rpm and 800 rpm and 2 N/cm2 torque. The kinematics of the devices was recorded by using a custom angle-measuring disc with a 50-mm diameter attached to the handpiece provided by the manufacturer, whereas their movement was captured by a high-speed camera at 2,400 frames per second, 800 x 800 pixel-resolution and distance of 0.3 m from the target object. Statistical analysis was performed at a significance level of 5%. At 400 rpm, the iRoot motor had a value of 17.94 rpm above that indicated by the manufacturer, which was significantly different from those of X-Smart Plus (5.20 rpm below that indicated by the manufacturer) and VDW.Silver (0.62 rpm above that indicated by the manufacturer) motors (P < 0.05). At 800 rpm, the iRoot motor had a value of 51.34 rpm below that indicated by the manufacturer, whereas the X-Smart Plus motor had a value of 13.00 rpm below that indicated by the manufacturer (P > 0.05). The VDW.Silver motor statistically differed from the iRoot and X-Smart Plus ones, showing a value of 1.68 rpm above that indicated by the manufacturer. In conclusion, the X-Smart Plus, VDW.Silver, and iRoot motors showed lower variations in the rotational speed values compared to those reported by their manufacturers. The endodontic motors presented different behaviors between them, with the VDW.Silver motor presents the most accurate values and the iRoot presents the most divergent values.

Resumo O presente estudo avaliou a real velocidade rotacional de três diferentes motores endodônticos comparados aos valores fornecidos pelos fabricantes. Um total de três motores endodônticos (X-Smart Plus, VDW.Silver e iRoot) foram testados a 400 rpm e 800 rpm e torque de 2 N/cm2. A cinemática dos dispositivos foi verificada utilizando-se um disco customizado de 50 mm de diâmetro acoplado ao contra ângulo fornecido pelo fabricante e o movimento foi capturado através de uma câmera ajustada em 2400 quadros por segundo com resolução de 800 x 800 pixels distante 0,3 m do objeto alvo. A análise estatística foi realizada com nível de significância de 5%. A 400 rpm, o motor iRoot apresentou 17,94 rpm acima do indicado pelo fabricante, sendo o valor significativamente diferente do X-Smart Plus (5,20 rpm abaixo do indicado pelo fabricante) e VDW.Silver (0.62 rpm acima do indicado pelo fabricante) (P > 0,05). A 800 rpm, iRoot apresentou 51.34 rpm abaixo do indicado pelo fabricante e X-Smart Plus 13,00 rpm abaixo do indicado pelo fabricante (P > 0,05). VDW.Silver foi estatisticamente diferente de iRoot e X-Smart Plus, apresentando 1,68 rpm acima do indicado pelo fabricante. Concluiu-se que os motores X-Smart Plus, VDW.Silver e iRoot apresentaram baixa variação na velocidade rotacional quando comparada ao fornecido pelo fabricante. Os motores endodônticos apresentaram diferentes comportamentos entre eles, sendo que o motor VDW.Silver apresentou valores mais acurados enquanto o iRoot foi o mais divergente.

Chemomechanical preparation influences the microbial community and the levels of LPS, LTA and cytokines in combined endodontic-periodontal lesions: A clinical study.

BACKGROUND: This study was conducted to compare the microbiomes, the levels of lipopolysaccharides (LPS), lipoteichoic acid (LTA), and cytokines (interleukin [IL]-1ß and tumor necrosis factor-alpha [TNF-α]), before and after chemomechanical preparation (CMP) of the root canals (RC) and their associated periodontal pockets (PP) in teeth with combined EPL. MATERIALS: Samples were taken from 10 RC and PP, before and after CMP. The microbiomes (next-generation sequencing, V3-V4 hypervariable region of the 16S rRNA gene), microbiome diversity (bioinformatics analyses), LPS (limulus amebocyte lysate), LTA, IL-1ß, and TNF-α (ELISA) were evaluated. A statistical analysis was performed with significance level set at 5%. RESULTS: The most abundant phyla in both sites were Firmicutes and Proteobacteria. Comparative studies of bacterial genera species revealed that some increased and others decreased after CMP at both sites. A 3% reduction in Gram-negative bacteria (RC) and a 4% increase in Gram-positive bacteria (PP) were detected. LPS levels were 4.4 times higher in PP than in the RC. LTA was detected in all samples investigated. Higher levels of IL-1ß and TNF-α were detected in both sites at baseline. After CMP, LPS, LTA, IL-1ß and TNF-α were reduced in both sites. CONCLUSION: The microbial community in the RC and PP in teeth with combined EPL indicated a similarity between both sites. CMP effectively reduced the microbial load and the LPS levels from teeth with EPL, and consequently diminished the cytokine levels. The reduction in LTA levels in the RC and PP proved challenging.

SARS-CoV-2: A Professional and social gamechanger - Medical and dental aspects

Abstract This study reports the SARS-CoV-2 outbreak and its impact on dental practice and education in Brazil. A literature review involving medical and dental interests was performed based on recent general findings about the infection (research and relevant guidelines). COVID-19 is a high transmissible, unpredictable systemic disease, involving a viral replication phase, followed by an inflammatory phase that can evolve into hyperinflammation that leads to a cytokine storm and other serious issues including sepsis, shock and multiple organ failure. The dentists are directly impacted by the new coronavirus as they work with the oral cavity that is irrigated by the saliva and receive the respiratory aerosols and droplets from the patient. In conclusion, the world is facing a completely new situation that deserves the comprehension of the population and close attention of the authorities. Following protocols to attend patients can prevent the dissemination of the virus, cross-infection, and the contamination of health care professionals. New strategies need to be developed to enhance the existing teaching and learning protocols in Universities and to allow research to continue.

Resumo Este estudo descreve o surto de SARS-CoV-2 e o impacto na prática e Ensino em odontologia no Brasil. Foi realizada uma revisão da literatura acerca de interesses médico e odontológico baseada em achados recentes sobre a infecção (pesquisa e diretrizes relevantes). COVID-19 é uma doença sistêmica altamente transmissível, imprevisível, envolvendo a fase de replicação viral, seguida da fase inflamatória que pode evoluir para um estado de hiper inflamação, levando a uma "tempestade de citocinas" e outros sintomas tais como sepse, choque e falência múltipla de órgãos. Os dentistas são diretamente impactados pelo novo coronavírus uma vez que trabalham com a cavidade oral que é irrigada pela saliva, e recebe aerossóis e gotículas oriundas da respiração do paciente. Concluiu-se que o mundo está enfrentando uma situação completamente nova e merece a compreensão da população e atenção das autoridades. Seguir protocolos para o atendimento de paciente pode prevenir a disseminação do virus, infecção cruzada e a contaminação de profissionais da saúde. Novas estratégias precisam ser desenvolvidas para melhorar os protocolos de Ensino e aprendizagem existentes nas universidades e permitir que a pesquisa continue.

Influence of Bacterial Profiles in Cytokine and Clinical Features of Endodontic Disease.

INTRODUCTION: We verified the association between selected bacterial profiles and levels of cytokines, chemokines, and the expression of signs and symptoms of primary endodontic infection with apical periodontitis. METHODS: Samples were collected from 21 root canals, and macrophages were stimulated for 24 hours. Tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-10, IL-12p70, interferon gamma, and chemokine (C-C motif) ligand 2 (CCL2) were measured using cytometric bead array. We investigated the overlapping networks between cytokines and chemokines with regression analysis. Checkerboard DNA-DNA hybridization was used to assess 40 target bacteria species. Using factor analysis, bacterial species aggregated in 2 factors. The association of bacteria species-based factors on cytokine and chemokine levels and clinical features was estimated with regression analysis. RESULTS: A negative relationship between IL-10 (anti-inflammatory cytokine) and CCL2, TNF-α, and IFN-γ (proinflammatory cytokines) (all P < .05) was observed. CCL2 was positively correlated with TNF-α (P < .01). Thirty-eight bacteria species were detected in primary endodontic infection with apical periodontitis. The first bacteria species-based factor was associated with the size of the radiolucent area (coefficient = 15.42) and tenderness to percussion/pain on palpation (coefficient = 20.79). The second factor was associated with CCL2 levels (coefficient = 1.28). CONCLUSIONS: Different bacterial profiles can be differentially related to the expression of inflammatory proteins and the experience of clinical features.

Teaching experiences during the SARS-COV-2 pandemic in a Brazilian School of Dentistry

The coronavirus outbreak (2019) represents a public health emergency of global concern. Several measures have been taken to minimise the risk of infection among the population, including social distancing, working from home, closure of non-essential activities since the detection of the first case in Brazil. This study describes the teaching experiences during the SARS-COV-2 pandemic in a Brazilian School of Dentistry. The State University of Campinas (UNICAMP) was the first public university in Brazil to stop all the classroom activities on 13th of March 2020 due to COVID-19, followed by other universities. UNICAMP developed several initiatives and created a special support page for digital teaching, where it is possible to obtain guidance, support materials for teachers and a space for exchanging messages (e-mail and chat) for specific guidelines. UNICAMP has started lending computer equipment to undergraduate and graduate students according to socioeconomic criteria. Along with the equipment, 500 chips have been delivered with 10 GB of internet so that these students are able to access the network and carry out the remote activities related to their courses. In conclusion, quality education is the key-element in forming high-quality professionals that will in a near future provide health care for the community, be part in international research groups and become lecturers

Effectiveness of XP-Endo Finisher in the reduction of bacterial load in oval-shaped root canals

Abstract: This study investigated the effectiveness of XP-Endo Finisher (XPF) associated with XP-Endo Shaper (XPS) or Reciproc Blue (RB) files in reducing bacterial load in oval-shaped root canals (RC) during chemomechanical preparation (CMP) using 0.9% saline solution (NaCl) or 2.5% sodium hypochlorite (NaOCl). Eighty mandibular incisors with single oval-shaped RC were contaminated with Enterococcus faecalis. The teeth were randomly assigned to eight experimental groups (n = 10) according to the CMP, as follows: G1: XPS, G2: XPS + XPF, G3: RB, and G4: RB + XPF. CMP was performed with NaCl or NaOCl. The reduction of bacterial load was assessed by colony-forming unit count before (S1) and after (S2) CMP. Data normality was verified by using Shapiro-Wilk test. ANOVA, Tukey's test, and Bonferroni post-hoc test were used at a 5% significance level. Culturable bacteria were present in all S1 samples (p>0.05). All instrumentation techniques were effective in reducing bacterial load, irrespective of the irrigating solution (p < 0.05). With the use of NaCl, RB was more effective than XPS (p = 0.035). With the use of NaOCl, XPS and RB presented similar effectiveness (p = 0.779). XPF enhanced the bacterial reduction of both systems tested (p < 0.05). The use of NaOCl improved the CMP, irrespective of the instrumentation technique used (p < 0.05). In conclusion, XPS and RB files are effective in reducing bacterial levels in oval-shaped RC. The use of XPF as a method of agitation of the irrigating solution improved the cleaning efficiency of both file systems tested. Mechanical preparation performed with saline solution decreased culturable bacteria from the root canal, but antimicrobial substances such as NaOCl should be used to achieve a significantly better disinfection.

Evaluation of apically extruded debris using positive and negative pressure irrigation systems in association with different irrigants

Abstract This study evaluated the amount of apically extruded debris after chemo-mechanical preparation (CMP) using positive and negative pressure irrigation systems [Conventional irrigation (CI) and EndoVac (EV)] in association with different irrigants [6% Sodium Hypochlorite (NaOCl), 2% Chlorhexidine gel + saline solution (CHXg + SS), 2% Chlorhexidine solution (CHXs) or Saline solution (SS)]. Eighty mandibular premolars with single root canals were selected and randomly assigned into 8 groups (n = 10) according to the irrigation system and the irrigant used during CMP: G1 (EV + NaOCl), G2 (EV + CHXg + SS), G3 (EV + CHXs), G4 (EV + SS), G5 (CI + NaOCl), G6 (CI + CHXg + SS), G7 (CI + CHXs) and G8 (CI + SS). Reciproc® R25 files (25/.08) were used during the CMP and the extruded debris from each tooth was collected in pre-weighted Eppendorf tubes and dried. The average weight of debris was assessed using a microbalance, and the data were statistically analyzed using ANOVA and the post hoc Tukey's test (a = 0.05). All groups were associated with debris extrusion. EV was the irrigation system with less extruded debris (p < 0.05). No differences were observed regarding the irrigant when EV was used. When CI was used, CHXg + SS were associated with lower debris extrusion (p < 0.05). It was concluded that no irrigation protocol succeeded in preventing debris extrusion. EV resulted in lower levels of debris extrusion than CI. The use of CHXg + SS resulted in lower debris extrusion.

Resumo Este estudo avaliou a quantidade de debris extruídos apicalmente após o preparo químico-mecânico (PQM) utilizando sistemas de irrigação com pressão positiva e negativa [irrigação convencional (IC) e EndoVac (EV)] em associação com diferentes irrigantes [hipoclorito de sódio 6% (NaOCl), clorexidina gel + solução salina (CLXg + SS), solução de clorexidina 2% (CLXs) ou solução salina (SS)]. Oitenta pré-molares inferiores com único canal radicular foram selecionados e aleatoriamente alocados em 8 grupos (n=10) de acordo com o sistema de irrigação e irrigante utilizado durante o PQM: G1 (EV + NaOCl), G2 (EV + CLXg + SS), G3 (EV + CLXs), G4 (EV + SS), G5 (IC + NaOCl), G6 (IC + CLXg + SS), G7 (IC + CLXs) e G8 (IC + SS). Limas Reciproc® R25 foram utilizadas durante o PQM e os debris extruídos de cada dente foi coletado em tubos pré-pesados e secos. O peso médio de debris foi avaliado por meio de microbalança, e os dados foram analisados estatisticamente utilizando ANOVA e teste de Tukey (a = 0.05). Todos os grupos foram associados com extrusão de debris. EV foi o sistema de irrigação com menos debris extruídos (p<0.05). Não foram observadas diferenças entre os irrigantes quando o EV foi utilizado. Quando foi utilizada IC, CLXg + SS foram associados a menor extrusão de debris (p<0.05). Concluiu-se que nenhum protocolo de irrigação conseguiu prevenir extrusão de debris. EV resultou em menores níveis de extrusão de debris que a IC. A utilização da CLXg + SS resultou em menor extrusão de debris.