Application of Mixed Reality to Ultrasound-guided Femoral Arterial Cannulation During Real-time Practice in Cardiac Interventions.

Mixed reality opens interesting possibilities as it allows physicians to interact with both, the real physical and the virtual computer-generated environment and objects, in a powerful way. A mixed reality system, based in the HoloLens 2 glasses, has been developed to assist cardiologists in a quite complex interventional procedure: the ultrasound-guided femoral arterial cannulations, during real-time practice in interventional cardiology. The system is divided into two modules, the transmitter module, responsible for sending medical images to HoloLens 2 glasses, and the receiver module, hosted in the HoloLens 2, which renders those medical images, allowing the practitioner to watch and manage them in a 3D environment. The system has been successfully used, between November 2021 and August 2022, in up to 9 interventions by 2 different practitioners, in a large public hospital in central Spain. The practitioners using the system confirmed it as easy to use, reliable, real-time, reachable, and cost-effective, allowing a reduction of operating times, a better control of typical errors associated to the interventional procedure, and opening the possibility to use the medical imagery produced in ubiquitous e-learning. These strengths and opportunities were only nuanced by the risk of potential medical complications emerging from system malfunction or operator errors when using the system (e.g., unexpected momentary lag). In summary, the proposed system can be taken as a realistic proof of concept of how mixed reality technologies can support practitioners when performing interventional and surgical procedures during real-time daily practice.

Caffeine and sport.

Caffeine is a trimethylxanthine found in coffee and several other foods and beverages. Its stimulatory effects make it an interesting strategy to boost performance for athletic populations. Scientific evidence supports its efficacy to improve high-intensity endurance exercise, explosive and high-intensity efforts, resistance exercise, team sports and combat sports, though individual variation in the ergogenic response to caffeine exists. Supplementation can be taken in many forms including dissolved in water, via capsules, coffee, energy drinks and caffeinated gum; ingestion via capsules, dissolved in water or in caffeinated gum appear to be most effective. Variability in the exercise response following caffeine supplementation may be explained by genetic factors or habitual caffeine consumption. Caffeine is an excellent supplement for athletes looking to improve their exercise performance, though some consideration of side-effects and impact on sleep are warranted.

Corrigendum: Schistosoma mansoni coactivator associated arginine methyltransferase 1 (SmCARM1) effect on parasite reproduction.

[This corrects the article DOI: 10.3389/fmicb.2023.1079855.].

Thirty-four years of Landsat monitoring reveal long-term effects of groundwater abstractions on a World Heritage Site wetland.

Wetlands are among the most biodiverse yet endangered ecosystems on Earth. Despite being the most important wetland in Europe, the Doñana National Park (southwestern Spain) is no exception, and the increase of nearby groundwater abstractions for intensive agriculture and human supply has raised international concerns about the conservation of this iconic wetland. It is thus needed to assess wetlands' long-term trends and responses to global and local factors to make informed management decisions. In this paper, we used 442 Landsat satellite images to analyze the historical trends and drivers of the date of desiccation and maximum flooded area in 316 ponds located in Doñana National Park during a 34-year period (1985-2018) and found that 59 % of the ponds studied are currently desiccated. The use of Generalized Additive Mixed Models (GAMMs) showed inter-annual variation in rainfall and temperature as the most important factors determining pond flooding. However, GAMMS also showed that intensive agriculture and the nearby tourist resort were related to the desiccation or shrinking of ponds all over Doñana, finding that the strongest negative flooding anomalies (i.e. ponds flooding less than explained by climate alone) were located in proximity to pumping areas. These results suggest that current levels of groundwater exploitation may be unsustainable and require urgent measures to control abstractions to ensure the integrity of the Doñana pond network, and the persistence of >600 wetland-dependent species.

Performing moderate to severe activity is safe and tolerable for healthy youth while wearing a cloth facemask.

OBJECTIVE: To investigate if a cloth facemask could affect physiological and perceptual responses to exercise at distinct exercise intensities in healthy young individuals. METHODS: Nine participants (sex, female/male: 6/3; age: 13±1 years; VO2peak: 44.5±5.5 mL/kg/min) underwent a progressive square-wave test at four intensities: (1) 80% of ventilatory anaerobic threshold (VAT), (2) VAT, and (3) 40% between VAT and [Formula: see text] wearing a triple-layered cloth facemask or not. Participants then completed a final stage to exhaustion at a running speed equivalent to the maximum achieved during the cardio-respiratory exercise test (Peak). Physiological, metabolic, and perceptual measures were measured. RESULTS: Mask did not affect spirometry (forced vital capacity, peak expiratory flow, forced expiratory volume; all p≥0.27), respiratory (inspiratory capacity, end-expiratory volume [EELV] to functional vital capacity ratio, EELV, respiratory frequency [Rf], tidal volume [VT], Rf/VT, end-tidal carbo dioxide pressure, ventilatory equivalent to carbon dioxide ratio; all p≥0.196), hemodynamic (heart rate, systolic and diastolic blood pressure; all p>0.41), ratings of perceived exertion (p = 0.04) or metabolic measures (lactate; p = 0.78) at rest or at any exercise intensity. CONCLUSIONS: This study shows that performing moderate to severe activity is safe and tolerable for healthy youth while wearing a cloth facemask. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04887714.

Schistosoma mansoni coactivator associated arginine methyltransferase 1 (SmCARM1) effect on parasite reproduction.

Introduction: The human blood fluke parasite Schistosoma mansoni relies on diverse mechanisms to adapt to its diverse environments and hosts. Epigenetic mechanisms play a central role in gene expression regulation, culminating in such adaptations. Protein arginine methyltransferases (PRMTs) promote posttranslational modifications, modulating the function of histones and non-histone targets. The coactivator-associated arginine methyltransferase 1 (CARM1/PRMT4) is one of the S. mansoni proteins with the PRMT core domain. Methods: We carried out in silico analyses to verify the expression of SmPRMTs in public datasets from different infection stages, single-sex versus mixed-worms, and cell types. The SmCARM1 function was evaluated by RNA interference. Gene expression levels were assessed, and phenotypic alterations were analyzed in vitro, in vivo, and ex vivo. Results: The scRNAseq data showed that SmPRMTs expression is not enriched in any cell cluster in adult worms or schistosomula, except for Smcarm1 expression which is enriched in clusters of ambiguous cells and Smprmt1 in NDF+ neurons and stem/germinal cells from schistosomula. Smprmt1 is also enriched in S1 and late female germ cells from adult worms. After dsRNA exposure in vitro, we observed a Smcarm1 knockdown in schistosomula and adult worms, 83 and 69%, respectively. Smcarm1-knockdown resulted in reduced oviposition and no significant changes in the schistosomula or adult worm phenotypes. In vivo analysis after murine infection with Smcarm1 knocked-down schistosomula, showed no significant change in the number of worms recovered from mice, however, a significant reduction in the number of eggs recovered was detected. The ex vivo worms presented a significant decrease in the ovary area with a lower degree of cell differentiation, vitelline glands cell disorganization, and a decrease in the testicular lobe area. The worm tegument presented a lower number of tubercles, and the ventral sucker of the parasites presented a damaged tegument and points of detachment from the parasite body. Discussion: This work brings the first functional characterization of SmCARM1 shedding light on its roles in S. mansoni biology and its potential as a drug target. Additional studies are necessary to investigate whether the reported effects of Smcarm1 knockdown are a consequence of the SmCARM1-mediated methylation of histone tails involved in DNA packaging or other non-histone proteins.

The crown lengthening double guide and the digital Perio analysis.

OBJECTIVE: This article describes a surgical crown lengthening double guide, which was digitally obtained to improve diagnosis, treatment outcome, and follow-up. CLINICAL CONSIDERATIONS: The rehabilitation of anterior dental esthetics should involve interdisciplinary and facially driven planning for achieving pleasant long-term outcomes. Surgical crown lengthening is one of the most common periodontal surgery, which can be assisted by digital tools to improve surgical planning and follow-up. CONCLUSION: The double guide for surgical crown lengthening allows the proper management of hard and soft tissues for achieving a predefined goal based on biological requirements and facially driven planning. In addition, the digital quality control allows the follow-up compared with the pre-operative condition and planned treatment plan. CLINICAL SIGNIFICANCE: The use of digital tools allow the clinician to develop a facially driven planning with proper communication with the team and patient, leading to a shorter, more predictable, and less invasive surgical technique, reducing postoperative inflammation and increasing patient comfort.

A Cloth Facemask Causes No Major Respiratory or Cardiovascular Perturbations During Moderate to Heavy Exercise.

PURPOSE: Investigate whether a cloth facemask could affect physiological and perceptual responses to exercise at distinct exercise intensities in untrained individuals. METHODS: Healthy participants (n = 35; 17 men, age 30 [4] y, and 18 women, age 28 [5] y) underwent a progressive square wave test at 4 intensities: (1) 80% of ventilatory anaerobic threshold; (2) ventilatory anaerobic threshold; (3) respiratory compensation point; and (4) exercise peak (Peak) to exhaustion, 5-minute stages, with or without a triple-layered cloth facemask (Mask or No-Mask). Several physiological and perceptual measures were analyzed. RESULTS: Mask reduced inspiratory capacity at all exercise intensities (P < .0001). Mask reduced respiratory frequency (P = .001) at Peak (-8.3 breaths·min-1; 95% confidence interval [CI], -5.8 to -10.8), respiratory compensation point (-6.9 breaths·min-1; 95% CI, -4.6 to -9.2), and ventilatory anaerobic threshold (-6.5 breaths·min-1; 95% CI, -4.1 to -8.8), but not at Baseline or 80% of ventilatory anaerobic threshold. Mask reduced tidal volume (P < .0001) only at respiratory compensation point (-0.5 L; 95% CI, -0.3 to -0.6) and Peak (-0.8 L; 95% CI, -0.6 to -0.9). Shallow breathing index was increased with Mask only at Peak (11.3; 95% CI, 7.5 to 15.1). Mask did not change HR, lactate, ratings of perceived exertion, blood pressure, or oxygen saturation. CONCLUSIONS: A cloth facemask reduced time to exhaustion but had no major impact on cardiorespiratory parameters and had a slight but clinically meaningless impact on respiratory variables at higher intensities. Moderate to heavy activity is safe and tolerable for healthy individuals while wearing a cloth facemask. CLINICALTRIALS: gov: NCT04887714.

Can I Have My Coffee and Drink It? A Systematic Review and Meta-analysis to Determine Whether Habitual Caffeine Consumption Affects the Ergogenic Effect of Caffeine.

OBJECTIVE: The aim was to quantify the proportion of the literature on caffeine supplementation that reports habitual caffeine consumption, and determine the influence of habitual consumption on the acute exercise response to caffeine supplementation, using a systematic review and meta-analytic approach. METHODS: Three databases were searched, and articles screened according to inclusion/exclusion criteria. Three-level meta-analyses and meta-regression models were used to investigate the influence of habitual caffeine consumption on caffeine's overall ergogenic effect and within different exercise types (endurance, power, strength), in men and women, and in trained and untrained individuals. Sub-analyses were performed according to the following: acute relative dose (< 3, 3-6, > 6 mg/kg body mass [BM]); whether the acute caffeine dose provided was lower or higher than the mean daily caffeine dose; and the caffeine withdrawal period prior to the intervention (< 24, 24-48, > 48 h). RESULTS: Sixty caffeine studies included sufficient information on habitual consumption to be included in the meta-analysis. A positive overall effect of caffeine was shown in comparison to placebo (standard mean difference [SMD] = 0.25, 95% confidence interval [CI] 0.20-0.30; p < 0.001) with no influence of relative habitual caffeine consumption (p = 0.59). Subgroup analyses showed a significant ergogenic effect when the caffeine dose was < 3 mg/kg BM (SMD = 0.26, 95% CI 0.12-0.40; p = 0.003) and 3-6 mg/kg BM (SMD = 0.26, 95% CI 0.21-0.32; p < 0.0001), but not > 6 mg/kg BM (SMD = 0.11, 95% CI - 0.07 to 0.30; p = 0.23); when the dose was both higher (SMD = 0.26, 95% CI 0.20-0.31; p < 0.001) and lower (SMD = 0.21, 95% CI 0.06-0.36; p = 0.006) than the habitual caffeine dose; and when withdrawal was < 24 h, 24-48 h, and > 48 h. Caffeine was effective for endurance, power, and strength exercise, with no influence (all p ≥ 0.23) of relative habitual caffeine consumption within exercise types. Habitual caffeine consumption did not modify the ergogenic effect of caffeine in male, female, trained or untrained individuals. CONCLUSION: Habitual caffeine consumption does not appear to influence the acute ergogenic effect of caffeine.

A Cloth Facemask Causes No Major Respiratory or Cardiovascular Perturbations during Moderate to Heavy Exercise

ObjectivesTo investigate whether wearing a cloth facemask could affect physiological and perceptual responses to exercise at distinct exercise intensities in non-trained men and women. MethodsIn a crossover design, participants (17 men and 18 women) underwent a progressive square-wave test at four intensities (i. at 80% of the ventilatory anerobic threshold [80%VAT]; ii. at VAT; iii. at the respiratory compensation point [RCP]; iv. at exercise peak [Peak] to exhaustion), with or without a triple-layered cloth mask (Mask or No-Mask). Several physiological, metabolic and perceptual measures were analyzed. ResultsMask reduced inspiratory capacity at all exercise intensities vs. No-Mask (p<0.0001), irrespective of sex. Mask reduced respiratory frequency vs. No-Mask (p=0.001) at Peak (-8.3 breaths{middle dot}min-1; CI: -5.8, -10.8), RCP (-6.9 breaths{middle dot}min-1; CI: -4.6, -9.2) and VAT (-6.5 breaths{middle dot}min-1; CI: -4.1, -8.8), but not at Baseline or at 80%VAT. Mask also reduced tidal volume (p<0.0001) at both RCP (-0.5L; CI: -0.3, -0.6) and Peak (-0.8L; CI: -0.6, -0.9), but not at Baseline, 80%VAT or VAT. Shallow breathing index was increased with Mask at Peak compared to No-Mask (11.3; CI: 7.5, 15.1), but not at any other intensities. Mask did not change heart rate, lactate, ratings of perceived exertion, blood pressure or oxygen saturation. ConclusionsWearing a cloth facemask during exercise at moderate to heavy intensities is unlikely to incur significant respiratory or cardiovascular changes, irrespective of sex. These data can inform new exercise recommendations for health during the COVID-19 pandemic and debunk unfounded allegations of harmful effects of masks during exercise. ClinicalTrials.gov: NCT04887714 What are the new findings?{checkmark} Using a progressive square-wave test, we showed that wearing a cloth facemask during exercise increased breathing difficulty, but this was dependent upon the exercise intensity. {checkmark}Respiratory variables (e.g., inspiratory capacity, respiratory frequency, shallow breathing index) were affected at higher rather than lower intensities. {checkmark}Mask wearing did not change heart rate, lactate, ratings of perceived exertion, blood pressure or oxygen saturation at any exercise intensity. {checkmark}There were no substantial sex differences on the effects of mask wearing during exercise. How might it impact on clinical practice in the future?{checkmark} These data can debunk unfounded allegations on harmful effects of masks during exercise, and help inform new exercise recommendations for health during the COVID-19 pandemic, particularly where facemasks remain necessary.

Nonplacebo Controls to Determine the Magnitude of Ergogenic Interventions: A Systematic Review and Meta-analysis.

INTRODUCTION: Placebos are used as a control treatment that is meant to be indistinguishable from the active intervention. However, where substantive placebo effects may occur, studies that do not include a nonplacebo control arm may underestimate the overall effect of the intervention (active plus placebo components). This study aimed to determine the relative magnitude of the placebo effect associated with nutritional supplements (caffeine and extracellular buffers) by meta-analyzing data from studies containing both placebo and nonplacebo control sessions. METHODS: Bayesian multilevel meta-analysis models were used to estimate pooled effects and express the placebo effect as a percentage of the overall intervention effect. RESULTS: Thirty-four studies were included, with the median pooled effect size (ES0.5) indicating a very small (ES0.5 = 0.09 (95% credible interval (CrI), 0.01-0.17)) improvement in the performance of placebo compared with control. There was no moderating effect of exercise type (capacity or performance), exercise duration, or training status. The comparison between active intervention and control indicated a small to medium effect (ES0.5 = 0.37 (95% CrI, 0.20-0.56)). Expressed in relative terms, the placebo effect was equivalent to 25% (75% CrI, 16%-35%) and 59% (75% CrI, 34%-94%) of the total intervention effect for buffers and caffeine. CONCLUSIONS: These results demonstrate a very small but potentially important placebo effect with nutritional supplementation studies. A substantive proportion of supplement effects may be due to placebo effects, with the relative proportion influenced by the magnitude of the overall ergogenic effect. Where feasible, intervention studies should use nonplacebo control-arm comparators to identify the proportion of the effect estimated to come from placebo effects and avoid underestimating the overall benefits that the physiological plus psychobiological aspects associated with an intervention provide in the real world.

Schistosoma mansoni FES Tyrosine Kinase Involvement in the Mammalian Schistosomiasis Outcome and Miracidia Infection Capability in Biomphalaria glabrata.

Schistosomiasis is a neglected tropical disease (NTD) caused by helminthes from the Schistosoma genus. This NTD can cause systemic symptoms induced by the deposition of parasite eggs in the host liver, promoting severe complications. Functional studies to increase knowledge about parasite biology are required for the identification of new drug targets, because the treatment is solely based on praziquantel administration, a drug in which the mechanism of action is still unknown. Protein kinases are important for cellular adaptation and maintenance of many organisms homeostasis and, thus, are considered good drug targets for many pathologies. Accordingly, those proteins are also important for Schistosoma mansoni, as the parasite relies on specific environmental signals to develop into its different stages. However, the specific roles of protein kinases in S. mansoni biology are not well understood. This work aims at investigating the tyrosine-protein kinase FES (Feline Sarcoma) functions in the maintenance of S. mansoni life cycle, especially in the establishment of mammalian and invertebrate hosts' infection. In this regard, the verification of Smfes expression among S. mansoni stages showed that Smfes is more expressed in infective free-living stages: miracidia and cercariae. Schistosomula exposed to SmFES-dsRNA in vitro presented a reduction in movement and size and increased mortality. Mice infected with Smfes-knocked-down schistosomula exhibited a striking reduction in the area of liver granuloma and an increased rate of immature eggs in the intestine. Female adult worms recovered from mice presented a reduced size and changes in the ovary and vitellarium; and males exhibited damage in the gynecophoral canal. Subsequently, miracidia hatched from eggs exposed to SmFES-dsRNA presented changes in its capability to infect and to sense the snail mucus. In addition, the SmFES RNAi effect was stable from miracidia to cercariae. The establishment of infection with those cercariae reproduced the same alterations observed for the knocked-down schistosomula infection. Our findings show that SmFES tyrosine kinase (1) is important in schistosomula development and survival; (2) has a role in adult worms pairing and, consequently, female maturation; (3) might be essential for egg antigen expression, thus responsible for inducing granuloma formation and immunomodulation; and (4) is essential for miracidia infection capability. In addition, this is the first time that a gene is kept knocked down during three different S. mansoni life stages and that a tyrosine kinase is implicated in the parasite reproduction and infection establishment in the mammalian host. Accordingly, SmFES should be explored as an alternative to support schistosomiasis treatment and morbidity control.

Utilização do Conceito Digital Smile Design na Odontologia Restauradora / Concept Using Digital Smile Desing in Dentistry Restorative

Due to the advancement of digital dentistry, the Digital Smile Design (DSD) technique has been gaining credibility on the part of professionals and patients. The planning of aesthetic and functional restorative treatments becomes more predictable with its use. This case report presents a patient with aesthetic complaint of the size and shape of her anterior teeth, associated with great gingival exposure. Photographs were important assistants in the planning of dental intervention. These were used for facial analysis, drawings of guidelines and more suitable dental forms. A software called Keynote was used, capable of managing photos, creating measurements, straight and curved lines, facilitating the planning of a new dental proportion. At the end of this process, the patient can observe, through the help of photographs, the new smile that was built virtually. That way, it became easier for her to accept the treatment plan, allowing her to make a test of her new smile with the mock-up.

Devido ao avanço da Odontologia digital, a técnica Digital Smile Design (DSD) vem ganhando credibilidade por parte dos profissionais e pacientes. O planejamento de tratamentos restauradores estéticos e funcionais torna-se mais previsível com sua utilização. Este relato de caso apresenta uma paciente com queixa estética do tamanho e forma dos seus dentes anteriores, associada a grande exposição gengival. Fotografias foram auxiliares importantes no planejamento da intervenção odontológica. Estas serviram para análises faciais, desenhos de linhas de orientação e de formas dentárias mais adequadas. Utilizou-se um software chamado Keynote, capaz de gerenciar fotos, criar medidas, linhas retas e curvas, facilitando o planejamento de uma nova proporção dental. Ao término deste processo a paciente pode observar, pelo auxílio das fotografias, o novo sorriso que foi construído virtualmente. Desta forma, tornou-se mais fácil, por parte dela, a aceitação do plano de tratamento, possibilitando que a mesma faça uma prova do seu novo sorriso com a realização do mock- up.

Can the Skeletal Muscle Carnosine Response to Beta-Alanine Supplementation Be Optimized?

Carnosine is an abundant histidine-containing dipeptide in human skeletal muscle and formed by beta-alanine and L-histidine. It performs various physiological roles during exercise and has attracted strong interest in recent years with numerous investigations focused on increasing its intramuscular content to optimize its potential ergogenic benefits. Oral beta-alanine ingestion increases muscle carnosine content although large variation in response to supplementation exists and the amount of ingested beta-alanine converted into muscle carnosine appears to be low. Understanding of carnosine and beta-alanine metabolism and the factors that influence muscle carnosine synthesis with supplementation may provide insight into how beta-alanine supplementation may be optimized. Herein we discuss modifiable factors that may further enhance the increase of muscle carnosine in response to beta-alanine supplementation including, (i) dose; (ii) duration; (iii) beta-alanine formulation; (iv) dietary influences; (v) exercise; and (vi) co-supplementation with other substances. The aim of this narrative review is to outline the processes involved in muscle carnosine metabolism, discuss theoretical and mechanistic modifiable factors which may optimize the muscle carnosine response to beta-alanine supplementation and to make recommendations to guide future research.

Selamento dentinário imediato: proposição de protocolos clínicos / Immediate dentin sealing: proposition for clinical protocols

O selamento dentinário imediato é uma técnica que visa à aplicação de um sistema adesivo imediatamente após a confecção do preparo dental e antes do procedimento de moldagem para a confecção de restaurações indiretas. Observou-se, através de revisão de literatura, que esta abordagem traz benefícios na resistência de união a cimentos resinosos e na prevenção à sensibilidade pós-operatória de dentes preparados para restaurações indiretas. Diversos sistemas adesivos, assim como cimentos resinosos, com diferentes formulações e técnicas de utilização, estão disponíveis no mercado. Sob esse enfoque, foi proposto um protocolo de utilização da técnica de selamento dentinário imediato para os diferentes tipos de restaurações indiretas(AU)

The immediate dentin sealing is a technique that comprises the application of an adhesive system immediately after tooth preparation and before impression taking for the fabrication of indirect restorations. Based on a literature review, it was observed that this approach has benefits regarding bonding strength of dentin to resin cements and decreases the post operatory sensitiveness of teeth prepared for indirect restorations. A number of adhesive systems, as well as resin cements, with different formulations and application protocols are available. Based on the available information, it was proposed a protocol for the application of the immediate dentin sealing technique for different types of tooth preparation(AU)

Uso da coroa clínica dentária natural como material restaurador para a prótese sobreimplante / Natural tooth crowns as definitive materials for single-tooth implant-supported prosthesis

Este trabalho teve como objetivo apresentar um caso clínico onde se utilizou implante osseointegrável e como restauração (provisória e definitiva) foi reaproveitada a coroa do incisivo central superior (hígido), extraído devido à fratura radicular. Previamente à execução do caso, solicitou-se uma tomografia computadorizada para confirmação da fratura. A exodontia foi realizada de forma menos traumática possível e o alvéolo foi instrumentado com abordagem palatina para instalação do implante. Um torque de 60 Ncm foi alcançado garantindo estabilidade primária do implante, permitindo a provisionalizacão imediata com o próprio incisivo da paciente. Cuidados foram tomados com os ajustes oclusais para se evitar contatos em MIH e durante as excursões mandibulares. Após seis meses de osseointegração, pôde-se observar excelente resposta dos tecidos moles ao redor da restauração e qualidade estética incomparável, graças à utilização do próprio elemento extraído. Desta forma, o trabalho definitivo foi concluído reaproveitando a face vestibular do mesmo incisivo central utilizado na fase provisória.

This paper aims to present a clinical report in which the upper central incisor´s natural crown (extracted due to root fracture) was used as a provisional and restorative material for an implant-supported prosthesis. Tooth fracture was confirmed by CT scanning. After, tooth extraction was performed and the alveolar socket received a “palatine approach” for the implant placement. After a 60 Ncm torque being reached, immediate provisionalization was made with the patient’s own incisor. The oclusal adjustments were done carefully in order to avoid any contact in maximum occlusion and during all mandibular excursions. After 6 months, the soft tissues showed excellent response around the restoration and a unique aesthetic quality. Thus, the “definitive” work was completed with the reuse of the buccal aspect of the same central incisor in provisional stage

A rationale method for evaluating unscrewing torque values of prosthetic screws in dental implants.

OBJECTIVES: Previous studies that evaluated the torque needed for removing dental implant screws have not considered the manner of transfer of the occlusal loads in clinical settings. Instead, the torque used for removal was applied directly to the screw, and most of them omitted the possibility that the hexagon could limit the action of the occlusal load in the loosening of the screws. The present study proposes a method for evaluating the screw removal torque in an anti-rotational device independent way, creating an unscrewing load transfer to the entire assembly, not only to the screw. MATERIAL AND METHODS: Twenty hexagonal abutments without the hexagon in their bases were fixed with a screw to 20 dental implants. They were divided into two groups: Group 1 used titanium screws and Group 2 used titanium screws covered with a solid lubricant. A torque of 32 Ncm was applied to the screw and then a custom-made wrench was used for rotating the abutment counterclockwise, to loosen the screw. A digital torque meter recorded the torque required to loosen the abutment. RESULTS: There was a significant difference between the means of Group 1 (38.62 ± 6.43 Ncm) and Group 2 (48.47 ± 5.04 Ncm), with p=0.001. CONCLUSION: This methodology was effective in comparing unscrewing torque values of the implant-abutment junction even with a limited sample size. It confirmed a previously shown significant difference between two types of screws.