Effects of heat in the properties of NaOCl alone and mixed with etidronate and alkaline tetrasodium EDTA

AIM

To assess the free available chlorine concentration (FAC), organic tissue dissolution and smear layer removal capacity of sodium hypochlorite (NaOCl) alone and when mixtured with etidronate (HEDP) and tetrasodium EDTA (Na₄ EDTA), and heated to different temperatures.

METHODOLOGY

Mixtures at 1 : 1 ratio of 5% NaOCl with distilled water (considered NaOCl alone), 18% HEDP or 10% Na₄ EDTA were heated to 25 °C, 37 °C, 48 °C and 60 °C. The FAC in the mixtures was assessed at 5, 10, 20, 30, 60 and 120 min. Samples of bovine muscle tissue (n = 10) were prepared with similar size and weighed before and after 5, 10 and 15 min of immersion in the mixtures heated to the different temperatures to verify organic matter dissolution. The intergroup results were compared statistically using one-way analysis of variance (anova) and intragroup by two-way analysis of variance (anova), both followed by Tukey's multiple-comparison test (α < 0.01). Bovine dentine blocks (n = 10) were analysed by scanning electron microscopy before and after immersion in the mixtures, and the time taken to remove the smear layer from the surfaces of the samples was determined. The Friedman test was used to compare the scores of the same group (α < 0.01), and the Kruskal-Wallis test with Dunn's post hoc was used to compare the different groups (α < 0.01). Saline solution was used as a control in the experiments of tissue dissolution and smear layer removal, RESULTS: Heating NaOCl alone did not affect its FAC. The higher the temperature of the mixtures with the chelators, the lower the FAC. Organic tissue dissolution was improved by increases in temperature of NaOCl alone and its mixture with HEDP (P < 0.01); however, the mixture with Na₄ EDTA had no improvement (P > 0.01). Smear layer removal by NaOCl alone was enhanced by heating resulting in lower scores in some samples and became more rapid in the mixtures with the chelators. The saline solution did not promote tissue dissolution nor smear layer removal (P > 0.01).

CONCLUSION

In this laboratory study, heating NaOCl alone or when mixed with HEDP improved its capacity to dissolve organic matter and remove the smear layer. However, the mixture with HEDP required frequent refreshment to retain these effects when heated. Due to the acceleration in the reaction between the irrigants, very rapid reductions in the free available chlorine in the mixtures with Na₄ EDTA heated to the different temperatures occurred.

Muscle hardness and masticatory myofascial pain: Assessment and clinical relevance

The impression of increased muscle hardness in painful muscles is commonly reported in the clinical practice but may be difficult to assess. Therefore, the aim of this review was to present and discuss relevant aspects regarding the assessment of muscle hardness and its association with myofascial temporomandibular disorder (TMD) pain. A non-systematic search for studies of muscle hardness assessment in patients with pain-related TMDs was carried out in PubMed, Cochrane Library, Embase and Google Scholar. Mechanical devices and ultrasound imaging (strain and shear wave elastography) have been consistently used to measure masticatory muscle hardness, although an undisputable reference standard is yet to be determined. Strain elastography has identified greater masseter hardness of the symptomatic side in patients with unilateral myofascial TMD pain when compared to the contralateral side and healthy controls (HC). Likewise, shear wave elastography has shown greater masseter elasticity modulus in patients with myofascial TMD pain when compared to HC, which may be an indication of muscle hardness. Although assessment bias could partly explain these preliminary findings, future randomised controlled trials are encouraged to investigate this relationship. This qualitative review indicates that the muscle hardness of masticatory muscles is still a rather unexplored field of investigation with a good potential to improve the assessment and potentially also the management of myofascial TMD pain. Nonetheless, the current evidence in favour of increased hardness in masticatory muscles in patients with myofascial TMD pain is weak, and the pathophysiological importance and clinical usefulness of such information remain unclear.

Análise da Retenção de Coroas CAD/CAM Cimentadas em Pilares do Tipo Ti-Base por Meio do Teste de Tração Pull-Out

Este estudo avaliou a resistência ao pull-out de coroas implantossuportadas confeccionadas em CAD/CAM e cimentadas em pilares de implante do tipo ti-base. Quarenta e cinco coroas foram fresadas para uso no pilar de implante ti-base (SIN Implante) e divididas (n15) de acordo com o material: Zircônia, Co-Cr ou Titânio. A cimentação foi realizada com cimento provisório Temp Bond NE (Kerr) ou cimento resinoso RelyX U200 (3M – Oral Care), sob carga de 50N por 10 minutos. As coroas foram submetidas ao   teste de tração em máquina de teste universal a 1,0 mm/min. Os testes foram feitos de acordo com a condição de cimentação: sem cimento (SC), cimentação provisória (CP, TempBond NE), sem cimento após a cimentação provisória (SCSP) e cimentação definitiva (CD, RelyX U200). Os resultados obtidos foram analisados por análise de variância e teste Tukey (p<0,05). Os valores médios de resistência (N) e desvio padrão foram: ZirSC (104,90/51,23) ZirCP (154,26/43,53) ZirSCCP (66,38/40,81) ZirCD (300,01/82,65) CoCrSC (72,38/43,07) CoCrCP (40,43/17,46) CoCrCD (900,35/133,63) TiSC (61,13/30,01) TiCP (158,85/22,18) TiSCCP (60,92/26,11) TiCD (566,66/75,82). Os materiais Co-Cr e titânio apresentaram maiores níveis de retenção ao pilar ti-base, na cimentação definitiva. O cimento RelyX U200 apresentou comportamento superior quando comparado ao cimento Temp Bond NE, independente do material da coroa.Palavras-chave: Implante Dentário. Cimentação. Coroa.

Antinociceptive, anti-inflammatory and antioxidant activities of aqueous extract from Remirea maritima (Cyperaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Remirea maritima Aubl., popularly known as "capim-da-praia", is popularly employed in the treatment of diarrhea, kidney disease, fever, and for analgesic and anti-inflammatory purposes through the preparation of teas. Few studies have focused on the chemical composition and its biological properties.

AIM OF THE STUDY

This work evaluated the antinocipetive, anti-inflammatory and antioxidant activities of the aqueous extract from Remirea maritima Aubl. as well as the isolation and identification of the chemical compounds.

MATERIALS AND METHODS

Compounds were isolated from aqueous extract of Remirea maritima through preparative HPLC and the structures were identified by means of NMR and MS analysis. The tests for antinociceptive, anti-inflammatory, and antioxidant activities, along with motor coordination test (Rota rod), were performed over the aqueous extract.

RESULTS

The phytochemical investigation of aqueous extract of Remirea maritima resulted in the isolation of three flavone glycosides. The structures of these compounds were determined by means of MS and 1D and 2D NMR data as vitexin-2″-O-β-D-glucopyranoside, isovitexin-2″-O-β-D-glucopyranoside, and luteolin-7-O-glucuronide. Acute pretreatment with aqueous extract (100, 200 or 400mg/kg, i.p.) caused a significant decrease (p<0.001) in the number of abdominal writhes. In the formalin test, higher doses significantly inhibited the late (inflammatory pain) phase of formalin-induced licking (p<0.05 or 0.001). In the hot plate test, there was no significant difference in nociceptive behavior, discarding the possible central effect of the aqueous extract. In the rota rod test, it was verified that the aqueous extract in all concentration evaluated does not alter the motor coordination of mice, such antinociceptive results were unlikely to be caused by motor abnormality. In the peritonitis test, induced by carrageenan, the treatment with aqueous extract produced a significant reduction in leukocyte migration in all concentration evaluated. Additionally, a significant reduction of lipoperoxidation (TBARS test) and in nitric oxide formation (.NO Scavenging assay) was observed in antioxidant activity assay.

CONCLUSION

The biological and phytochemical investigations of the aqueous extract of Remirea maritima resulted in the identification of three flavone glycosides that have been described here for the first time in Remirea and effective analgesic activity in various pain models, probably mediated via the inhibition of peripheral mediators which could be related to its strong antioxidant effect observed in vitro.

Antinociceptive effect of citronellal in mice

Citronellal is a monoterpene reported to be a major component of the essential oils in various aromatic species of plants. The present study evaluated the central nervous system depressant and antinociceptive properties of citronellal through behavioral experimental models. Following intraperitoneal injection, citronellal induced the reduction of spontaneous activity, ataxia, analgesia, and sedation. In pentobarbital-induced hypnosis, CTL (citronellal) at 50, 100, and 200 mg/kg (i.p.) significantly increased sleeping time (88.0 +/- 11.4, 100.2 +/- 16.4, and 119.5 +/- 20.9 min) when compared to vehicle solution injections (43.0 +/- 6.1). Citronellal (100 and 200 mg/kg, i.p.) significantly reduced the number of writhes (66.4 and 81.9%) in a writhing test and the number of paw licks during phase 1 (47.0 and 66.8%) and phase 2 (71.1 and 79.2%) of a formalin test when compared to control group animals. In addition, the results of a hot plate test showed central analgesic properties for citronellal (p < 0.05). These results indicate depressant, hypnotic, and antinociceptive properties of this monoterpene.

Phythochemical screening and anticonvulsant activity of Cymbopogon winterianus Jowitt (Poaceae) leaf essential oil in rodents

Cymbopogon winterianus (Poaceae) is used for its analgesic, anxiolytic and anticonvulsant properties in Brazilian folk medicine. This report aimed to perform phythochemical screening and to investigate the possible anticonvulsant effects of the essential oil (EO) from fresh leaves of C. winterianus in different models of epilepsy. The phytochemical analysis of EO showed presence of geraniol (40.06%), citronellal (27.44%) and citronellol (10.45%) as the main compounds. A behavioral screening demonstrated that EO (100, 200 and 400mg/kg; ip) caused depressant activity on CNS. When administered concurrently, EO (200 and 400mg/kg, ip) significantly reduced the number of animals that exhibited PTZ- and PIC-induced seizures in 50% of the experimental animals (p<0.05). Additionally, EO (100, 200 and 400mg/kg, ip) significantly increased (p<0.05) the latencies of clonic seizures induced by STR. Our results demonstrated a possible activity anticonvulsant of the EO.

Molar bite force and its correlation with signs of temporomandibular dysfunction in mixed and permanent dentition

The aim of the study was to evaluate molar bite force (BF) magnitude and its correlation to the signs of temporomandibular dysfunction (TMD), gender, weight, height and age in 101 students ranging in age from 6 to 18 years (32 boys/21 girls with mixed dentition and 23 boys/25 girls with permanent dentition). TMD clinical signs were evaluated using the Craniomandibular Index (CMI), and two subscales, the Dysfunction Index (DI) and the Palpation Index (PI). BF was determined with a pressurized tube connected to a sensor (MPX5700-Motorola SPS). anova, Tukey's test, and Pearson's and Spearman's coefficients were evaluated. BF was higher in the permanent dentition (P < 0.05). There was no difference in BF between genders within the groups, but boys with permanent dentition had higher values than children with mixed dentition (P < 0.05). The girls with permanent dentition presented negative correlation in BF with PI and CMI (P < 0.05). BF was positively correlated with weight, height and age in the permanent dentition group (P < 0.05). It was concluded that BF increased from mixed to permanent dentition, with an assumed enhancing influence of body variables and ageing. The TMD signs in older girls were correlated to decreasing BF, suggesting an influence of muscle tenderness preventing subjects from exerting maximum BF.

Ultrasound and tomographic evaluation of temporomandibular joints in adolescents with and without signs and symptoms of temporomandibular disorders: a pilot study

OBJECTIVES

Condylar position in the glenoid fossa has been linked to temporomandibular disorders (TMDs); however its importance in TMD aetiology is still unclear. The purpose of this study was to determine joint spaces and condylar position in adolescents with TMDs using ultrasound static images and linear corrected tomograms at the mandibular rest position.

METHODS

Craniomandibular index (CMI) and a symptom questionnaire were assessed in 217 subjects aged 12-18 years. Those with the lowest and the highest scores were divided into control (n=20) and SSTMD (presence of signs and symptoms of TMD) groups (n=20). Ultrasound images and tomography were used to measure the distance between the capsule and the lateral surface of the condyle and to determine the condyle location at the mandibular resting position, respectively.

RESULTS

The mean distances obtained from ultrasound images did not correlate with CMI scores and they did not differ between the two groups (P>0.05). Posterior positioned condyles were determined on tomograms, and they were more prevalent both in the SSTMD group (P=0.05) and in girls (P<0.05).

CONCLUSIONS

Even though there was a significant difference in condyle position between the control and SSTMD groups, determined by axially corrected tomograms, it cannot be inferred that posteriorly positioned condyles can predict TMDs. In addition, there was no association between the articular capsule and the lateral condyle surface distances measured by ultrasound using a 10 MHz linear transducer and the clinical diagnosis of TMD. Further studies in diagnostic imaging of TMJs with ultrasound should be encouraged, since it has some useful diagnostic applications and does not require special facilities.

Bite force determination in adolescents with and without temporomandibular dysfunction

The aims of this study were to compare bite force in adolescents with and without temporomandibular dysfunction (TMD), and to investigate the influence of gender, age, height and weight on bite force magnitude. The TMD was evaluated using a self-report questionnaire and the Craniomandibular Index, which has two subscales, the Dysfunction Index and the Palpation Index. Subjects with lower and upper extremity values were used to integrate the control (Group I -n = 20) and TMD (Group II -n = 20) groups, respectively. In addition, the TMD group should have at least one subjective symptom. Bite force was determined with a transducer, which consisted of a pressurized rubber tube connected to a sensor element (MPX 5700 - Motorola SPS, Austin, TX, USA). Analysis of covariance, Pearson's coefficient, Mann-Whitney and t-tests were applied to analyse the data. The results showed that Group II presented smaller values for bite force than Group I and boys had greater values than girls in Group II (P < 0.05). Bite force values were significantly smaller for girls between groups (P < 0.05), whereas for boys there was no statistical difference. Weak positive correlation between bite force and weight, height and age (P > 0.05) and significant negative correlation between bite force and Palpation and Craniomandibular Indexes (P < 0.05) were found. It was concluded that decreased bite force was correlated with TMD in girls, primarily with muscle tenderness.

Relationship between oral parafunctional/nutritive sucking habits and temporomandibular joint dysfunction in primary dentition

The aim of this study was to evaluate the relationship between nutritive and parafunctional habits and the presence of temporomandibular dysfunction (TMD) in children with primary dentition.

METHODS

Ninety nine children, aged 3-5 years, were examined to check for the presence or absence of signs and symptoms of TMD (headache, preauricular pain, earache, masticatory muscle tenderness, deviation on opening, occlusal interference and asymmetric movement of the mandible), oral parafunctions (bruxism, nail biting, finger/thumb sucking, speech alteration, mouth breathing, pacifier and atypical swallowing) and nutritive habits (breast- or bottle-feeding) through interview and clinical examination. The results were submitted to descriptive statistical analysis and Fisher's exact test.

RESULTS

The results showed that only atypical swallowing was positively related to TMD (P < 0.0001); other oral parafunctional and nutritive habits were not related to TMD.

CONCLUSIONS

It was concluded that parafunctional habits, with the exception of atypical swallowing, and feeding methods were not determinants for the presence of signs and/or symptoms of TMD in the sample of children included in the study.