In vitro inflammatory modulation of bioceramic endodontic sealer in macrophages stimulated by bacterial lipopolysaccharide.

AIM: To evaluate the effects of AH Plus (Dentsply), Sealer 26 (Dentsply), and Sealer Plus BC (Produtos Médicos e Odontológicos) on cytotoxicity and inflammation in macrophage cultures exposed to bacterial lipopolysaccharide (LPS). METHODOLOGY: After initial setting, the sealers were conditioned with serum-free culture medium for 24 h (1 ml/cm2 ). Macrophages from the RAW 264.7 strain were exposed to sealer extracts in a 1:16 ratio in a culture medium with or without LPS. Cell morphology, viability, mitochondrial activity, oxidative stress and gene expression of interleukin 1ß (IL-1ß) and tumour necrosis factor-alpha (TNF-α) were evaluated. Data on mitochondrial activity, oxidative stress and TNF-α were analysed using a two-way analysis of variance (anova) test, followed by the Student-Newman-Keuls post-test. IL-1ß data were analysed using one-way anova, followed by SNK, and the t-test was used for intragroup comparison. The significance level was set at 5%. RESULTS: In the absence of LPS, only AH Plus and Sealer 26 showed a reduction in cell density, while in the presence of LPS, Sealer 26 had the lowest density compared to the other groups. In terms of mitochondrial activity, at 24 and 48 h, Sealer Plus BC had significantly higher mean values than Sealer 26 and AH Plus (p < .05). Sealer 26 exhibited the lowest levels of oxidative stress and IL-1ß and TNF-α expression, regardless of the presence of LPS (p < .05). CONCLUSIONS: Although all sealers interfere with the response of macrophages to LPS, contact with epoxy resin-based sealers can impair cell activity in vitro, while bioceramic sealer seems to favour the inflammatory functions of these cells.

The sciatic and radial nerves seem to adapt similarly to different ladder-based resistance training protocols.

The present study aimed to compare the morphological response induced by different ladder-based resistance training (LRT) protocols on the peripheral nerve ultrastructure of young adult Wistar rats. Twenty-nine rodents were distributed into groups: control (CON), submaximal (SUBMAX [6 climbs/session, moderate intensity, 3x/week]) and maximum (MAX [> 4 climbs/session, maximum intensity, 3x/week]) LRT. After 8 weeks, the radial and sciatic nerves were removed and prepared for transmission electron microscopy. In the radial nerve, the myelinated fibers and axons, myelin sheath thickness, and unmyelinated axons were statistically greater in the SUBMAX and MAX. The MAX group had greater unmyelinated fibers than SUBMAX. The Schwann cell (SC) nuclei diameter was statistically larger in the SUBMAX than the CON. The number of microtubules and neurofilaments was statistically higher in the SUBMAX and MAX. In the sciatic nerve, the myelinated fibers, myelinated and unmyelinated axons, and myelin sheath thickness were statistically greater in the SUBMAX and MAX. The SUBMAX and MAX had more SC at the nuclei level than CON. The SC nuclei were statistically larger in the SUBMAX and MAX. The number of microtubules and neurofilaments was statistically higher in the SUBMAX and MAX. Total training load and total load per climb were not different between groups. The SUBMAX and MAX statistically increased maximum carried load (ML). In conclusion, the different LRT protocols induced similar morphological responses in radial and sciatic nerves, probably due to load progression and equal total load volume.

Ladder-based resistance training elicited similar ultrastructural adjustments in forelimb and hindlimb peripheral nerves of young adult Wistar rats.

To analyze the morphological response induced by high-volume, high-intensity ladder-based resistance training (LRT) on the ultrastructure of the radial (forelimb) and sciatic (hindlimb) nerves of adults Wistar rats. Twenty rats were equally distributed into groups: sedentary (SED) and LRT. After the rodents were subjected to the maximum load (ML) carrying test, the LRT group performed 6-8 progressive climbs (2 × 50% ML, 2 × 75% ML, 2 × 100% ML, and 2 × 100% ML + 30 g) three times per week. After 8 weeks, the radial and sciatic nerves were removed and prepared for transmission electron microscopy. In the radial nerve, myelinated axons cross-sectional area (CSA), unmyelinated axons CSA, myelin sheath thickness, and Schwann cells nuclei area were statistically larger in the LRT group than SED (p < 0.05). Also, the number of microtubules and neurofilaments per field were statistically higher in the LRT group than in SED (p < 0.01). For sciatic nerve, myelinated fibers CSA, unmyelinated axons CSA, myelin sheath thickness, Schwann cells nuclei area, and the number of neurofilaments per field were statistically larger in the LRT group compared to the SED group (p < 0.05). LRT with high-volume and high-intensity effectively induce similar changes in adult Wistar rats' radial and sciatic nerves' ultrastructure.

Effects of different lengths of high-intensity interval training microcycles on the systemic and hippocampal inflammatory state and antioxidant balance of immature rats.

There is a lack of evidence on the effects of high-intensity interval training (HIIT) microcycle duration on the antioxidant capacity and hippocampal inflammatory response of young (immature) samples. This study compared two HIIT microcycles lengths on adaptation to training, antioxidant balance, and systemic and hippocampal inflammation in immature rats. Twenty-four immature Wistar rats (27 days) were equally divided into groups: control; 4-day HIIT (3 training days + 1 rest day); and 7-day HIIT (6 training days + 1 rest day). Both microcycles of 4 and 7 days were 28 days of training (37-38 m min-1). Running performance improved in all training groups compared to controls (P < 0.05). However, the 7-day HIIT group statistically increased serum interleukin-6 (IL-6) compared to the control and 4-day HIIT groups (P < 0.05). The total serum antioxidant capacity in the 7-day HIIT group was statistically lower than in the control group (P < 0.05). There was no statistical difference for the analysis of serum malondialdehyde between the groups. The hippocampal gene expression of IL-6, IL-1ß, IL-10, and tumor necrosis factor-alpha in the training groups was statistically higher than in the control group (P = 0.01), with no significant difference between the 4-day HIIT and 7-day HIIT groups. We concluded that HIIT microcycles with a longer duration decrease the antioxidant capacity and increase the systematic and hippocampal inflammation. Thus, we suggest using short HIIT microcycles for young (immature) groups due to improved running performance with less inflammatory and antioxidant changes.

Effect of canal preparation with XP-endo Shaper and ProTaper Next on root canal geometry and dentin thickness of mandibular premolars with radicular grooves and two canals: a micro-CT study.

OBJECTIVES: This study aimed to evaluate the effects of different shaping protocols on the root canal geometry and remaining dentin thickness of mandibular premolars with radicular grooves (RG) and two canals by means of micro-CT. MATERIALS AND METHODS: Mandibular premolars with RG and two canals were matched based on their similar morphological dimensions and assigned to 2 experimental groups according to the canal preparation (n=8): XP-endo Shaper (XPS) and ProTaper Next (PTN) systems. Before and after preparation, morphometric measurements of the volume, surface area, structure model index, area, perimeter, roundness, major and minor diameters, as well as untouched canal walls, canal transportation, and dentin wall thickness were evaluated. Data were statistically compared within and between groups using the independent sample t test (α=5%). RESULTS: XPS revealed less changes in volume, surface area, area, perimeter, and major and minor diameters (P<0.05). There was no significant difference in structure model index (SMI), roundness, and percentage of untouched canal walls between groups (P>0.05). XPS resulted in less apical canal transportation and a higher remaining dentin thickness toward the RG compared to PTN in lingual canals (P<0.05). CONCLUSIONS: XPS revealed fewer changes in root canal geometry as well as lower transportation and a greater remaining dentin thickness in the lingual canals toward the RG compared to PTN. CLINICAL RELEVANCE: Internal and external anatomical characteristics of mandibular premolars might have an influence on biomechanical preparation. Considering the risk of perforation, the canal preparation using XPS appears to be more conservative compared to PTN.

Remodeling of the skeletal muscle and postsynaptic component after short-term joint immobilization and aquatic training.

Joint immobilization is commonly used as a conservative treatment for osteoarticular and musculotendinous traumas. However, joint immobilization might elicit degenerative effects on the neuromuscular system and muscle atrophy. For this reason, the choice of strategies that mitigate these effects is essential in the post-immobilization period. Therefore, this study aimed to investigate the impact of aquatic training on the morphology of muscle fibers and motor endplates of the gastrocnemius muscle in the post-immobilization period. Male Wistar rats (90 days old) were divided into groups: Sedentary: no procedure; Immobilization: joint immobilization protocol (10 days); Immobilization/non-training: joint immobilization protocol (10 days) followed by four weeks without exercise intervention; Immobilization/training: joint immobilization protocol (10 days) and post-immobilization aquatic training (4 weeks). After the procedures, we quantified the cross-sectional area (CSA), volume and numerical density of different myofibers types, and total and stained area and perimeter of the motor endplate. We demonstrate the following main results: (a) short-term joint immobilization resulted in myofibers atrophy; however, we verified a small change in the postsynaptic component; (b) the period of inactivity after immobilization caused severe changes in the motor endplate (lower stained area, stained perimeter, total area, and total perimeter) and maintenance of muscle atrophy due to immobilization; (c) the prescription of post-immobilization exercise proved to be effective in restoring muscle morphology and inducing plasticity in the motor endplate. We conclude that short-term joint immobilization (10 days) results in atrophy type I and II myofibers, in addition to a decline in the total perimeter of the motor endplate. Besides, the post-immobilization period appears to be decisive in muscle and postsynaptic remodeling. Thus, aquatic training is effective in stimulating adjustments associated with muscle hypertrophy and plasticity of the motor endplate during the post-immobilization period.

Chronic cachaça consumption affects the structure of tibial bone by decreasing bone density and density of mature collagen fibers in middle-aged Wistar rats.

Several studies have demonstrated that alcohol consumption can decrease bone density and alter its structure. However, most of the studies did not investigate the effects of specific alcoholic beverages. This study determined the effects of chronic consumption of cachaça (a Brazilian beverage containing alcohol) on body weight (BW), tibia bone density and on the tibia collagen density in middle-aged Wistar rats. Rats with 9 months old were submitted for 100 days, to a liquid diet of cachaça diluted in water with a progressive and controlled concentration (10°GL, 15°GL, 20°GL, 25°GL, and 30°GL). Chronic cachaça intake produced a significant decrease in BW and altered bone remodeling, decreasing trabecular bone density. In chronic cachaça-treated group (CT), the production of collagen fibers in bone tissue has predominantly green birefringence. It appears that they are immature fibers that do not exist in the control group, in which there are standard predominantly yellowish mature fibers. In conclusion, chronic cachaça consumption affects the structure of the tibial bone of middle-aged rats by decreasing the bone density and reducing the density of mature collagen fibers.

Muscle gene expression of CGRP-α, CGRP receptor, nAchR-ß, and GDNF in response to different endurance training protocols of Wistar rats.

The neuromuscular junction underwent adaptations to meet the demands of muscles following increased muscle activity. This study aimed to investigate the effects of high-intensity interval training (HIIT), endurance training (END), and mixed interval training (MIX) on the gene expression of the calcitonin gene-related peptide-α (CGRP-α), CGRP receptor, nicotinic acetylcholine receptors (nAchR)-ß and glial-derived neurotrophic factor (GDNF) among different muscle types. Male Wistar rats were randomly divided into four groups: Control (n = 8), END (n = 8), HIIT (n = 8), and MIX (n = 8). The animals run each training protocol for 8 weeks (five sessions/week). Forty-eight hours after the last training session, the muscles gastrocnemius and soleus were excised under the sterilized situation. After collection, the material was prepared for RNA extraction, Reverse Transcriptase reaction, and qPCR assay. The HIIT training up-regulated the CGRP-α (p < 0.01), CGRP-Rec (p < 0.01), and GDNF (p < 0.01) in soleus as well as the nAchR-ß (p < 0.01) and GDNF (p < 0.01) in gastrocnemius muscles. END training down-regulated the gene expression of CGRP-α (p < 0.01), and nAchR-ß (p < 0.01) in gastrocnemius but up-regulated nAchR-ß (p = 0.037) in soleus and GDNF (p < 0.01) in gastrocnemius muscles. MIX training did not show any significant up or down-regulation. The endurance performance of HIIT and MIX groups was higher than the END group (p < 0.01). All studied genes up-regulated by HIIT training in a muscle type-specific manner. It seems that the improvement of some synaptic indices induced by HIIT resulted in the improvement of endurance performance.

Gluteus Maximus Activation during Common Strength and Hypertrophy Exercises: A Systematic Review.

The gluteus maximus (GMax) is one of the primary hip extensors. Several exercises have been performed by strength and conditioning practitioners aiming to increase GMax strength and size. This systematic review aimed to describe the GMax activation levels during strength exercises that incorporate hip extension and use of external load. A search of the current literature was performed using PubMed/Medline, SportDiscuss, Scopus, Google Scholar, and Science Direct electronic databases. Sixteen articles met the inclusion criteria and reported muscle activation levels as a percentage of a maximal voluntary isometric contraction (MVIC). The exercises classified as very high level of GMax activation (>60% MVIC) were step-up, lateral step-up, diagonal step-up, cross over step-up, hex bar deadlift, rotational barbell hip thrust, traditional barbell hip thrust, American barbell hip thrust, belt squat, split squat, in-line lunge, traditional lunge, pull barbell hip thrust, modified single-leg squat, conventional deadlift, and band hip thrust. We concluded that several exercises could induce very high levels of GMax activation. The step-up exercise and its variations present the highest levels of GMax activation followed by several loaded exercises and its variations, such as deadlifts, hip thrusts, lunges, and squats. The results of this systematic review may assist practitioners in selecting exercised for strengthening GMax.

Barbell Hip Thrust, Muscular Activation and Performance: A Systematic Review.

The present systematic review aimed to analyze the activation of the muscles involved in the barbell hip thrust (BHT) and its transfer to sports activities that include horizontal displacement. A search of the current literature was performed using the PubMed, SPORTDiscuss, Scopus and Google Scholar databases. The inclusion criteria were: (a) descriptive studies, (b) physically trained participants, (c) analyzed muscle activation using normalized EMG signals or as a percentage of maximal voluntary isometric contraction (MVIC) and (d) acute or chronic transfer of the BHT to horizontal displacement activity. Twelve articles met the inclusion criteria and the following results were found: 1) neuromuscular activation: hip extensor muscles (gluteus maximus and biceps femoris) demonstrated greater activation in the BHT compared to the squat. The straight bar deadlift exercise demonstrated greater biceps femoris activation than BHT; 2) Regardless of the BHT variation and intensity used, the muscle excitation sequence is gluteus maximus, erector spinae, biceps femoris, semitendinosus, vastus lateralis, gluteus medius, vastus medialis and rectus femoris; 3) acute transfer: four studies demonstrated a significant improvement in sprinting activities after BHT exercise; 4) as for the chronic transfer: two studies demonstrated improvement of the sprint time, while other two studies failed to present such effect. We concluded that: a) the mechanics of BHT favors greater activation of the hip extensor muscles compared to more conventional exercises; b) regardless of the variation of BHT used, the muscle excitation sequence is gluteus maximus, erector spinae, hamstrings, and quadriceps femoris; c) the acute transfer of the post-activation potentiation of the BHT is significant, improving the sprinting time; and d) despite training with BHT submaximal loads can improve sprint times, further investigations are needed.

Total training load may explain similar strength gains and muscle hypertrophy seen in aged rats submitted to resistance training and anabolic steroids.

This study aimed to quantify training parameters and analyze the morphological response of aged muscles submitted to resistance training and anabolic steroids. Aged Wistar rats were divided into groups: C - initial control; CF - final control; CAS - control with anabolic steroid, RT - resistance training, and RTA - resistance training with anabolic steroid. Maximum carried load, absolute and relative loads increased significantly in RT and RTA. RTA demonstrated greater relative load than RT. Average total volume, total climbing volume, relative total volume, relative total climbing volume, and mean climbing volume were similar between groups RT and RTA. For soleus, CAS, RT, and RTA enlarged cross-sectional area of type I fibers and nuclear ratio. As for type II fibers, RTA was higher than C and CF. For plantaris, RT and RTA showed significant increases in myofibers type I compared to C and CF. For type II fibers, RTA showed a significant increase compared to C and CF. Regarding the nuclear ratio, RT and RTA showed a higher ratio than C, CF, and CAS. Our results demonstrated that both RT and RTA were not different among the analyzed morphological parameters. This fact can be explained by the absence of differences found in the training variables analyzed.

Effects of resistance training on liver structure and function of aged rats.

The aging process may cause negative physiological changes. However, exercises as resistance training (RT) have been considered an important intervention to attenuate these changes. Additionally, liver plays an important role in blood glucose homeostasis in exercise. AIM: This study aimed to analyze the effects of RT on the liver components of aged animals. METHODS: Male Wistar rats were divided into two groups: 24 months' group (CONTROL); and group submitted to a progressive RT protocol for 16 weeks (EXERCISE). Both groups were sacrificed at 24 months. RESULTS: We observed a decrease in blood flow due to the practice of resistance exercises. Besides, our results showed that hepatic tissue plays an important role in glycemic homeostasis during RT. In addition, RT increased mitogen capacity of hepatocytes. CONCLUSIONS: Our study showed many implications for the knowledge about the effects of strength training on old animals' liver.

Influence of laser irradiation on the push-out bond strength between a glass fiber post and root dentin.

STATEMENT OF PROBLEM: A major issue related to the failure of endodontically treated teeth restored with an intraradicular post is gradual debonding of the glass fiber post, resin cement, and dentin. PURPOSE: The purpose of this in vitro study was to evaluate the influence of laser irradiation on the push-out bond strength of glass fiber posts to radicular dentin. MATERIAL AND METHODS: Thirty-two mandibular bovine incisors were endodontically treated and divided into 4 groups according to the surface treatment of the post: silane control (GC); irradiation with Er:YAG (GYAG); irradiation with Er,Cr:YSGG (GCR); and 980-nm diode laser (GDI) application. After surface treatment, the glass fiber posts were cemented with dual adhesive resin cement. To evaluate bond strength, the specimens were subjected to a push-out test at a crosshead speed of 0.5 mm/min using a universal testing machine. Failure mode was analyzed using stereomicroscopy. The surface morphology was evaluated qualitatively after surface treatment by using confocal laser microscopy. The push-out test data (MPa) were analyzed using a linear mixed effects model and the Bonferroni test (α=.05). RESULTS: At the cervical third, no significant differences were observed between the GC and GCR groups (P=1.00), and both of the groups exhibited higher bond strength. At the middle and apical thirds, the GCR group revealed higher bond strength, which was significantly different from that observed in all other groups (P<.05). No statistical differences were observed among the other tested protocols (GC, GYAG, and GDI groups; P=1.00). Adhesive failure was predominant in all groups. CONCLUSIONS: Irradiation with Er,Cr:YSGG improved the bond strength of the cement-post-dentin interfaces.

Effects of testosterone administration on liver structure and function in aging rats.

Aging males have a decrease in testosterone levels, by which the testosterone treatment may influence in a negatively fashion the liver. AIM: This study aimed to analyze the effects of aging with or without testosterone administration on the liver components of animals. METHODS: Wistar rats were divided into three groups: 20 months' group (G20), 24 months' group (G24), group treated with testosterone for 16 weeks (GT). All groups were sacrificed at 24 months except for G20 that was sacrificed at 20 months. RESULTS: Aging and testosterone treatment alters the body weight (BW), liver weight (LW) and relative liver weight. Besides, testosterone increased the mitogen capacity of hepatocytes. Nonetheless, we reinforce the negative effects of testosterone on old animals' liver as chronic hepatic congestion and/or cholestasis. In addition, we observed that testosterone plays an important role on hepatic glycogen stores. CONCLUSIONS: Our study showed many implications for the knowledge about the effects of aging with or without testosterone administration on old animals' liver.

Caloric restriction minimizes aging effects on the femoral medial condyle.

This study aimed to analyze the effects of caloric restriction on aged femoral articular cartilage of Wistar rats. Three groups of eight animals each were considered: young (YC) and old (OC) control groups fed with a normal diet and old caloric restriction group (OCR) composed of 18-month-old animals fed with a 31% less caloric diet from 6-months of age. Articular cartilage was studied through morphometry and immunohistochemistry. Body mass was 12% less in the OCR group than in the OC group. The articular cartilage from OC rats show thinner medial condyles, fewer chondrocytes, smaller chondrocytes nuclear volume and, in both condyles, a predominance of collagen type II and less collagen density compared to both YC and OCR groups (p < .001). In contrast, OCR articular cartilage show thicker medial condyles, larger chondrocytes nuclear volume and increased collagen density compared to OC group (p < 0.001). We concluded that caloric restriction minimizes the effects of aging on medial condyles of the femoral articular cartilage.

Effect of a 12-methacryloyloxy-dodecyl-pyridinium-bromide-containing adhesive with different post types on the long-term bond strength to dentin.

The use of matrix metalloproteinase (MMPs) inhibitors, such as 12-methacryloyloxy-dodecyl-pyridinium-bromide (MDPB), might improve the adhesion of glass-fiber (GF) and polyfiber (PF) posts to root dentine. This study assessed the effect of an MDPB-containing adhesive on the long-term bond strength of GF or PF posts to bovine dentine. Bovine endodontically treated roots were randomly divided into six groups, according to the post type and adhesive system used, as follows: GF serrated post + MDBP-free adhesive; GF serrated post + MDPB-containing adhesive; GF smooth post + MDBP-free adhesive; GF smooth post + MDPB-containing adhesive; PF post + MDBP-free adhesive; PF post + MDPB-containing adhesive. Specimens were stored in water for 6 months, thermocycled (500 cycles wk-1 ), and submitted to the pull-out test and failure pattern analysis. The cement-dentin interface was evaluated using scanning electron microscopy. The pull-out data were analyzed using anova and Tukey's test (α = 0.05). No significant interaction between the type of post and the adhesive system was found. Polyfiber posts showed lower bond strength than GF posts, whether serrated or smooth, and the bond strength of the serrated and smooth GF posts was not significantly different. Adhesive failures were predominant in all groups. The type of retainer influenced the bond strength, and MDPB-containing adhesive did not improve the long-term bond strength of posts to dentine.

Posterior reversible encephalopathy syndrome as a complication of Henoch-Schönlein purpura in a seven-year-old girl.

Introduction Henoch-Schönlein purpura is a multisystem small vessel vasculitis. Neurologic manifestations are uncommon. Posterior reversible encephalopathy syndrome is a rare complication of Henoch-Schönlein purpura with typical clinical and neuroimaging findings that occurs most commonly in the setting of severe hypertension and renal injury. Case presentation A seven-year-old girl was admitted to our institution presenting with clinical and laboratory findings suggestive of Henoch-Schönlein purpura. Glucocorticoid therapy was initiated, but five days following her admission, she developed altered consciousness, seizures, arterial hypertension, and cortical blindness. Brain MRI scan revealed areas of vasogenic oedema in parieto-occipital lobes, consistent with posterior reversible encephalopathy syndrome. She was immediately initiated on antihypertensives and antiepileptics, which successfully improved her neurologic symptoms. Further laboratory work-up disclosed a rapidly progressive glomerulonephritis secondary to Henoch-Schönlein purpura that was the likely cause of her sudden blood pressure elevation. Immunosuppressive therapy was undertaken, and at one-year follow-up, the patient exhibited complete renal and neurologic recovery. Conclusion Posterior reversible encephalopathy syndrome is a severe complication of Henoch-Schönlein purpura. If promptly diagnosed and treated, children with Henoch-Schönlein purpura presenting with posterior reversible encephalopathy syndrome usually have a good prognosis. Clinicians should be familiar with the characteristic presentation of posterior reversible encephalopathy syndrome and be aware that hypertension and renal injury may predispose Henoch-Schönlein purpura patients to developing this complication.

Thermal effects and morphological aspects of varying Er:YAG laser energy on demineralized dentin removal: an in vitro study.

The aim of this study was to evaluate thermal changes, dentin ablation removal capacity, and morphological aspects of sound and demineralized human dentin surface irradiated with different output energies of an erbium: yttrium-aluminium-garnet (Er:YAG) laser. Eighty sound human tooth specimens were assigned into two groups: demineralized dentin and sound dentin (control group). The dentin groups were subdivided into four subgroups (n = 10) according to the irradiation energy used (120, 160, 200, or 250 mJ) at a constant frequency level of 6 Hz, in focused mode, and under refrigeration. Quantitative analysis of the sound and carious dentin ablation was performed using light microscopy (LM) by measuring (mm) the remaining demineralized tissue with the Axion Vision™ software. Qualitative analysis was performed using the images obtained with a scanning electron microscope (SEM), and the temperature increase was recorded with an infrared digital thermometer. The Er:YAG laser promoted a gradual increase in temperature for all groups, and no difference was observed between the sound and demineralized dentin. The groups of 200 and 250 mJ showed the highest values, yet a variation in temperature did not exceed 5 °C. The energy output of 120 mJ selectively removed demineralized tissue when compared to 250 mJ, while also providing more regular surfaces in the cavity preparation. It was concluded that the temperature increase during sound and demineralized dentin removal had a strong positive correlation with the Er:YAG laser energy level output. However, the higher energies used did not present selectivity to the demineralized tissue, and the parameters used did not cause an increase in temperature over 5 °C.

Nd:YAG laser in occlusal caries prevention of primary teeth: a randomized clinical trial.

Dental caries is still the most prevalent chronic disease affecting human populations. Among the preventive treatments performed, it has been reported that laser irradiation combined with topical fluoride can induce an even greater increase in enamel caries resistance. The aim of this study was to evaluate the Nd:YAG laser, with or without fluoride, in occlusal caries prevention of the primary dentition. A double-blind split-mouth study design was used. Fifty-two children with high caries risk (7.6 ± 1.4 years) were selected and received the following: G1--the first molar was a negative control, and the second received a resin sealant; G2--the first molar was a negative control, and the second received laser irradiation (50 mJ, 10 Hz, 0.5 W); G3--the first molar received only acidulate phosphate fluoride (APF), and the second received APF + laser; G4--fisrt molar received only fluoride varnish, and the second received fluoride varnish + laser. Patients were followed up to 12 months to evaluate the presence of white-spot lesions and/or caries cavities by three calibrated observers. Thirty-five patients completed the study. Significant differences were found between the treatment and control groups (p < 0.05). The laser-alone and resin sealant resulted in statistically lower caries formation than the negative control group (p < 0.05). Nd:YAG laser irradiation in primary teeth effectively prevented occlusal caries in pits and fissures when used alone with lower energy over a 1-year period.

Ladder-based resistance training with the progression of training load altered the tibial nerve ultrastructure and muscle fiber area without altering the morphology of the postsynaptic compartment.

Scientific evidence regarding the effect of different ladder-based resistance training (LRT) protocols on the morphology of the neuromuscular system is scarce. Therefore, the present study aimed to compare the morphological response induced by different LRT protocols in the ultrastructure of the tibial nerve and morphology of the motor endplate and muscle fibers of the soleus and plantaris muscles of young adult Wistar rats. Rats were divided into groups: sedentary control (control, n = 9), a predetermined number of climbs and progressive submaximal intensity (fixed, n = 9), high-intensity and high-volume pyramidal system with a predetermined number of climbs (Pyramid, n = 9) and lrt with a high-intensity pyramidal system to exhaustion (failure, n = 9). myelinated fibers and myelin sheath thickness were statistically larger in pyramid, fixed, and failure. myelinated axons were statistically larger in pyramid than in control. schwann cell nuclei were statistically larger in pyramid, fixed, and failure. microtubules and neurofilaments were greater in pyramid than in control. morphological analysis of the postsynaptic component of the plantar and soleus muscles did not indicate any significant difference. for plantaris, the type i myofibers were statistically larger in the pyramid and fixed compared to control. the pyramid, fixed, and failure groups for type ii myofibers had larger csa than control. for soleus, the type i myofibers were statistically larger in the pyramid than in control. pyramid and fixed had larger csa for type ii myofibers than control and failure. the pyramid and fixed groups showed greater mass progression delta than the failure. We concluded that the LRT protocols with greater volume and progression of accumulated mass elicit more significant changes in the ultrastructure of the tibial nerve and muscle hypertrophy without endplate changes.