Morphological alterations in dentine after mechanical treatment and ultrashort pulse laser irradiation

The aim of this study was to evaluate and compare the morphological changes that occur in dentine after femtosecond laser irradiation and after mechanical treatment. The duration of the laser pulse is an important parameter, because within the time frame of the pulse heat diffusion plays a very important role in the mechanism of interaction between the light and the tissue. Six totally impacted human third molars were sectioned into sheets approximately 1 mm thick with an Accutom-50 precision cutting machine. The samples were randomly divided into two groups according to their cavity preparation: mechanical cavity preparation and laser cavity preparation. The samples were then examined by light microscopy and scanning electron microscopy. There were clear differences in the results obtained with the two techniques. Cavities prepared with the laser with pulses of <1 ps showed no microcracks, and the treated surface displayed a rough and irregular aspect with no smear layer and exhibited open dentinal tubules. On the contrary, cavities made with a rotatory instrument had a smooth surface and microcracks, a broad area of carbonization and merging, occluded dentinal tubules and a smear layer. This study showed that human dentine can be successfully ablated with the ultrashort pulse laser.A.G. and P.M. acknowledge the support of Spanish Ministerio de Ciencia e Innovación through the Consolider Program SAUUL (CSD2007-00013) and research project FIS2009-09522, from Junta de Castilla y León through the Program for Groups of Excellence (GR27) and of the EC Seventh Framework Programme (LASERLAB-EUROPE, grant agreement no. 228334). We also acknowledge the support of the Centro de Laseres Pulsados, CLPU, Salamanca, Spain

Evaluation of micromorphological changes in tooth enamel after mechanical and ultrafast laser preparation of surface cavities

The aim of this in vitro study was to evaluate the morphological changes that occur in tooth enamel after mechanical instrumentation and after femtosecond laser irradiation with different parameters via light and scanning electron microscopy (SEM). Twelve totally impacted third molars were collected and sectioned to provide several cut surfaces. These surfaces were exposed to infrared (λ = 795 nm, 120 fs, 1-kHz repetition rate, maximum mean power 1 W) laser pulses and machined by means of a conventional mechanical technique. Two very different geometrical patterns were performed with femtosecond laser pulses: shallow rectangular cavities and deep cylindrical ones. The results of both machining procedures were examined using light and scanning electron microscopy. The SEM images show the femtosecond laser ability to produce high-precision cavities in tooth enamel. No signs of collateral damage, burning, melting, or cracks were observed despite the far different laser pulse energies used (ranging from 7 to 400 μJ), unlike what is seen with conventional mechanical techniques. The femtosecond laser has the potential to become an optimal tool for the treatment of dental decay and as an alternative to the conventional drill to reduce mechanical damage during removal of the hard dental tissue.A.G. and P.M. acknowledge the support of Spanish Ministerio de Ciencia e Innovación through the Consolider Program SAUUL (CSD2007-00013) and research project FIS2009-09522, from Junta de Castilla y León through the Program for Groups of Excellence (GR27) and of the EC Seventh Framework Programme (LASERLAB-EUROPE, grant agreement no. 228334).We also acknowledge the support of the Centro de Laseres Pulsados, CLPU, Salamanca, Spain

Apexificación con hidróxido de calcio vs tapón apical de MTA

Cuando los dientes inmaduros sufren un traumatismo se puede producir una necrosis pulpar que conlleva a la detención de desarrollo de estos dientes, cuyos conductos presentarán unas paredes paralelas o divergentes en el tercio apical. Esto supone un desafío endodóncico y restaurador, ya que la forma apical divergente hace casi imposible limpiar y conformar el conducto y, sobre todo, obturarlo correctamente. Gracias a la técnica de inducir la formación de una barrera apical (Apicoformación) empleando hidróxido de calcio se han conseguido innumerables éxitos mediante la obtención de un cierre apical. Sin embargo la susceptibilidad de estos dientes a fracturas hace que el pronóstico del tratamiento sea menos favorable. Esto puede deberse al efecto proteolítico del hidróxido de calcio. Desde hace unos años se realizan apicoformaciones mediante el empleo de MTA como tapón apical. Las propiedades de este material, así como los resultados obtenidos en los tratamientos, hacen del MTA un material idóneo para tratamientos de apicoformación. Además esta técnica permite reducir el tiempo de tratamiento necesario para una apicoformación clásica con hidróxido de calcio

Root anatomy and canal configuration of the permanent mandibular first molar: A systematic review

Introduction: The main goal of endodontic therapy is to prevent or heal apical periodontitis. However, root canal anatomy might present a clinical challenge directly related to the treatment outcome. The purpose of this study was to review published literature related to root anatomy and root canal configuration of the permanent mandibular first molar. Methods: An exhaustive search was undertaken to identify published literature related to the root anatomy and root canal morphology of the permanent mandibular first molar by using key words. The search of the MEDLINE database included all publications from 1966-May 2010. Selected articles were then obtained and reviewed. Data evaluated and summarized in the data sheet included methodology, population, number of teeth per study (power), number of root canals, type of root canal configuration, and identification of number of apical foramina. Results: Forty-one studies were identified including a total of 18,781 teeth. The incidence of a third root was 13% and was strongly correlated with the ethnicity of the studied population. Three canals were present in 61.3%, 4 canals in 35.7%, and 5 canals in approximately 1%. Root canal configuration of the mesial root revealed 2 canals in 94.4% and 3 canals in 2.3%. The most common canal system configuration was Vertucci type IV (52.3%), followed by type II (35%). Root canal configuration of the distal root revealed type I configuration in 62.7%, followed by types II (14.5%) and IV (12.4%). The presence of isthmus communications averaged 54.8% on the mesial and 20.2% on the distal root. Conclusions: The number of roots on the mandibular first molar is directly related to ethnicity. Root canal morphology and configuration might present the clinician with a complex anatomy requiring more diagnostic approaches, access modifications, and clinical skills to successfully localize, negotiate, disinfect, and seal the root canal system. (J Endod 2010;36:1919-1931)3.291 JCR (2010) Q1, 3/77 Dentistry, oral surgery & medicin

Internal morphology of the mandibular first permanent molar. Influence of the use of ultrasonic tips and operating microscope in locating canals

Introducción: Estudios recientes reflejan la existencia de conductos accesorios en las raíces de los primeros molares permanentes inferiores. El objetivo principal de este trabajo es determinar la influencia que tienen el uso de ultrasonidos y el microscopio operatorio en la localización de dichos conductos. Como objetivo secundario, hemos empleado la técnica de diafanización de manera innovadora para visualizar la anatomía real de los molares inferiores tratados. Metodología: Se realizó la apertura de 53 primeros molares permanentes inferiores en varias fases, anotando el número de conductos localizados en cada una de ellas. La primera, sin magnificación ni ultrasonidos. A continuación se incorporaron la puntas ultrasónicas y, en una tercera fase, se añadió el microscopio operatorio. Finalmente se utilizó la técnica descrita por Robertson para diafanizar los dientes y describir sus sistemas de conductos mediante la clasificación de Vertucci, modificada por diversos autores. Resultados: Tanto el uso de ultrasonidos como del microscopio operatorio, aumentaron el número de conductos localizados, pero las diferencias sólo fueron estadísticamente significativas con el uso simultáneo de ambos. Su ayuda fue más importante en la raíz mesial que en la distal. Un 26.4% de las raíces mesiales presentaba tres orificios de entrada a la cámara pulpar, cuyas configuraciones hacia la zona apical son variables. Tras diafanizar las muestras, un 23.1% presentaba 5 conductos. Conclusiones: El uso del microscopio operatorio y los ultrasonidos es importante para la localización de conductos accesorios en los primeros molares inferiores. La incidencia del conducto mesiocentral fue del 26.4%. La técnica de diafanización debería ir precedida de una apertura modificada bajo magnificación.No data (2012)UE

Root canal morphology of the permanent mandibular incisors by cone beam computed tomography: A systematic review

Knowledge of dental anatomy through the assessment of the anatomic variations of each tooth’s root canal system is essential to undertake endodontic therapy. The aim of this systematic review was to analyze the different studies on the internal morphology of permanent mandibular incisors where Cone-Beam Computed Tomography (CBCT) X-ray imaging is used. Pubmed, CENTRAL, Wiley Library and Web of Science electronic databases were searched for scientific studies included until March 2020. The terms used in the search were: “permanent mandibular incisors”, “root canal morphology” and “cone-beam computed tomography”. The search was limited to studies whose aim was the analysis of the morphology of the root canal system evaluating the parameters of methodology, population, sample, number and configuration. A total of 19 studies met the inclusion criteria. There was a noticeable lack of unanimity in the setting adjustments of each of the CBCT devices used. The presence of two root canals varied from 0.4% to 45%. The most frequent configurations were Vertucci’s Types I, III, II, V, IV, VII and VI. Type VIII configuration was non-existent. CBCT revealed the existence of anatomical symmetry patterns, and there was no unanimity of criteria regarding the presence of a second root canal. Results concerning the presence of a second root canal in the mandibular incisors differ widely, with a possible influence of the geographic area where the study was conducted. The prevalence of a second canal is higher in mandibular lateral incisors than in mandibular central incisors. There was no direct relationship between voxel size (0.125–0.3 mm) and increased prevalence of a second canal.Sin financiación2.679 JCR (2020) Q3, 101/178 Chemistry, Multidisciplinary0.435 SJR (2020) Q2, 366/2196 Computer Science ApplicationsNo data IDR 2020UE

Phylogenetic diversity of rhizobia nodulating Phaseolus vulgaris in Croatia and definition of the symbiovar phaseoli within the species Rhizobium pisi

7 páginas, 3 figuras y 1 tablaPhaseolus vulgaris is a legume indigenous to America which is currently cultivated in Europe including countries located at the Southeast of this continent, such as Croatia, where several local landraces are cultivated, most of them of Andean origin. In this work we identify at species and symbiovar levels several fast-growing strains able to form effective symbiosis with P. vulgaris in different Croatian soils. The identification at species level based on MALDI-TOF MS and core gene sequence analysis showed that most of these strains belong to the species R. leguminosarum, R. hidalgonense and R. pisi. In addition, several strains belong to putative new species phylogenetically close to R. ecuadorense and R. sophoriradicis. All Croatian strains belong to the symbiovar phaseoli and harbour the α and γ nodC alleles typical for American strains of this symbiovar. Nevertheless, most of Croatian strains harboured the γ nodC gene allele supporting its Andean origin since it is also dominant in other European countries, where Andean cultivars of P. vulgaris are traditionally cultivated, as occurs in Spain. The only strains harbouring the α nodC allele belong to R. hidalgonense and R. pisi, this last only containing the symbiovars viciae and trifolii to date. This is the first report about the presence in Europe of the species R. hidalgonense, the nodulation of P. vulgaris by R. pisi and the existence of the symbiovar phaseoli within this species. These results significantly increase the knowledge of the biogeography of Rhizobium-P. vulgaris symbiosis.Peer reviewe

Role of mTOR inhibitor in the cellular and humoral immune response to a booster dose of SARS-CoV-2 mRNA-1273 vaccine in kidney transplant recipients

Background: Immunocompromised patients have an increased risk of developing severe COVID disease, as well as a tendency to suboptimal responses to vaccines. The objective of this study was to evaluate the specific cellular and humoral adaptive immune responses of a cohort of kidney transplant recipients (KTR) after 3 doses of mRNA-1273 vaccine and to determinate the main factors involved. Methods: Prospective observational study in 221 KTR (149 non infected), 55 healthy volunteers (HV) and 23 dialysis patients (DP). We evaluated anti-spike (by quantitative chemiluminescence immunoassay) and anti-nucleocapsid IgG (ELISA), percentage of TCD4+ and TCD8+ lymphocytes producing IFNγ against S-protein by intracellular flow cytometry after Spike-specific 15-mer peptide stimulation and serum neutralizing activity (competitive ELISA) at baseline and after vaccination. Results: Among COVID-19 naïve KTR, 54.2% developed cellular and humoral response after the third dose (vs 100% in DP and 91.7% in HV), 18% only showed cell-mediated response, 22.2% exclusively antibody response and 5.6% none. A correlation of neutralizing activity with both the IgG titer (r=0.485, p1000/mm3 [4.68 (1.72-12.73, p=0.003], eGFR>30 mL/min [7.34(2.72-19.84), p<0.001], mTOR inhibitors [6.40 (1.37-29.86), p=0.018]. Infected KTR developed a stronger serologic response than naïve patients (96.8 vs 75.2%, p<0.001). Conclusions: KTR presented poor cellular and humoral immune responses following vaccination with mRNA-1273. The immunosuppression degree and kidney function of these patients play an important role, but the only modifiable factor with a high impact on humoral immunogenicity after a booster dose was an immunosuppressive therapy including a mTOR inhibitor. Clinical trials are required to confirm these results.Depto. de Inmunología, Oftalmología y ORLFac. de MedicinaTRUEpu