Liposomal lidocaine gel for topical use at the oral mucosa: characterization, in vitro assays and in vivo anesthetic efficacy in humans.

OBJECTIVE: To characterize liposomal-lidocaine formulations for topical use on oral mucosa and to compare their in vitro permeation and in vivo anesthetic efficacy with commercially available lidocaine formulations. MATERIALS AND METHODS: Large unilamellar liposomes (400 nm) containing lidocaine were prepared using phosphatidylcholine, cholesterol, and α-tocoferol (4:3:0.07, w:w:w) and were characterized in terms of membrane/water partition coefficient, encapsulation efficiency, size, polydispersity, zeta potential, and in vitro release. In vitro permeation across pig palatal mucosa and in vivo topical anesthetic efficacy on the palatal mucosa in healthy volunteers (double-blinded cross-over, placebo controlled study) were performed. The following formulations were tested: liposome-encapsulated 5% lidocaine (Liposome-Lido5); liposome-encapsulated 2.5% lidocaine (Liposome-Lido2.5); 5% lidocaine ointment (Xylocaina®), and eutectic mixture of lidocaine and prilocaine 2.5% (EMLA®). RESULTS: The Liposome-Lido5 and EMLA showed the best in vitro permeation parameters (flux and permeability coefficient) in comparison with Xylocaina and placebo groups, as well as the best in vivo topical anesthetic efficacy. CONCLUSION: We successfully developed and characterized a liposome encapsulated 5% lidocaine gel. It could be considered an option to other topical anesthetic agents for oral mucosa.

Effect of articaine on mental nerve anterior portion: histological analysis in rats.

OBJECTIVES: The aim of this study was to evaluate the possible toxic effects of articaine and lidocaine on mental nerve, due to the increasing number of paresthesia cases after nerve blocks. MATERIALS AND METHODS: The drugs were injected in the anterior portion of mental nerve of 24 rats, divided into three groups: G1--4% articaine with 1:100,000 epinephrine; G2--2% lidocaine with 1:100,000 epinephrine and G3--plain 1:100,000 epinephrine solution. These solutions were injected in the right side of the rat's mandible and the left side was used as control (0.9% saline solution). Previously to the injections, the animals were anesthetized with thiopental and, 24 h after the injections, their jaws were removed and submitted to routine histological techniques. A histopathological analysis was performed by optical microscopy. RESULTS: An inflammatory infiltration was found around mental nerve, classified as intense for G3, moderate for G1 and light for both G2 and control groups. No injuries were found in nervous structure, despite the inflammatory reaction observed around it. CONCLUSION: The results suggest that articaine is not toxic to the nervous structure and further studies are necessary to explain the possible relation between articaine injection and paresthesia.

Does bonding to dentin reduce microleakage of composite restorations?

This study evaluated the effect of adhesive application only to enamel on the marginal microleakage of composite resin restorations performed with different adhesive systems. Standardized cylinder-shaped cavities were prepared on the buccal surface of eighty bovine incisors. Two etch-and-rinse (Adper Scotchbond Multi-purpose [3M ESPE, St. Paul, MN USA] and Adper Single Bond 2 [3M ESPE]) and two self-etching (Clearfil SE Bond [Kuraray, Osaka, Japan] and Adper Prompt [3M ESPE]) adhesive systems were evaluated. The adhesives were applied only to enamel or to both dentin and enamel. After adhesive light-activation, the cavities were restored with composite resin. The samples were coated with two layers of nail polish, except an area of 1-mm wide around of the restoration, and immersed in a methylene blue solution. Afterwards, the specimens were ground in order to obtain powder which was immersed in absolute alcohol. The solutions were centrifuged and the supernatant was analyzed using an absorbance spectrophotometer. Linear regression was used to estimate the dye concentration. Data were analyzed using ANOVA and Tukey's tests (alpha = 0.05). The etch-and-rinse adhesives showed lower microleakage means compared to those of the self-etching adhesives. Adper Prompt presented higher microleakage means. There was no difference between the modes of application of the adhesive on the cavity for all adhesive systems, except for Clearfil SE Bond. This showed lower microleakage when applied to the whole cavity. Bonding to dentin may not reduce microleakage of composite restorations.

Comparison between Analgesia Nociception Index (ANI) and self-reported measures for diagnosing pain in conscious individuals: a systematic review and meta-analysis.

The Analgesia Nociception Index (ANI), an objective measure of pain based on heart rate variability (HRV), has its usefulness in awake patients still unclear. This systematic review and meta-analysis aimed to assess ANI's accuracy compared to self-reported pain measures in conscious individuals undergoing medical procedures or painful stimuli. PubMed, Ovid, Web of Science, Scopus, Embase, and grey literature were searched until March 2021. Of the 832 identified citations, 16 studies complied with the eligibility criteria. A meta-analysis including nine studies demonstrated a weak negative correlation between ANI and NRS for pain assessment in individuals in the post-anesthetic recovery room (r = - 0.0984, 95% CI = - 0.397 to 0.220, I2 = 95.82%), or in those submitted to electrical stimulus (r = - 0.089; 95% CI = - 0.390 to 0.228, I2 = 0%). The evidence to use ANI in conscious individuals is weak compared to self-report measures of pain, yet ANI explains a part of self-report. Therefore, some individuals may be benefited from the use of ANI during procedures or in the immediate postoperative period.

Anesthetic efficacy of liposomal prilocaine in maxillary infiltration anesthesia.

Animal studies have shown that liposome encapsulation increases prilocaine anesthetic efficacy. This randomized, blind, crossover, three-period study evaluated the anesthetic efficacy of liposome-encapsulated 3% prilocaine, compared to 3% plain prilocaine and 3% prilocaine with 0.03IU/mL felypressin, after a 1.8-mL infiltration in the buccal sulcus of the maxillary right canine, in 32 volunteers. Anesthesia success, onset, and duration of pulpal and gingival anesthesia in the lateral incisor, and canine and first premolar were evaluated. Injection pain was assessed by a visual analog scale (VAS). Results were submitted to Kruskal-Wallis (onset and duration of pulpal anesthesia), Tukey (VAS), Friedman (duration of gingival anesthesia), and log-rank and McNemar tests (anesthesia success) (α = 5%). Liposomal prilocaine did not differ from plain prilocaine (P > 0.05), but presented lower anesthesia success and duration for canine, premolar, and gingival anesthesia (P < 0.05) than prilocaine with felypressin. Liposomal prilocaine did not differ from the other formulations concerning onset and anesthesia success for the lateral incisor (p > 0.05); plain prilocaine presented lower success rates and slower onset of anesthesia for this tooth, in comparison to prilocaine with felypressin (P < 0.05). No differences were observed among the formulations in relation to duration of anesthesia for lateral incisor, VAS scores, and onset of gingival and pulpal anesthesia for the canine and premolar (P > 0.05). In conclusion, liposomal prilocaine presents similar anesthetic efficacy in relation to plain prilocaine and lower efficacy, in comparison to prilocaine with felypressin in maxillary infiltration. Prilocaine does not seem to benefit from liposomal encapsulation.

The effect of residual water on antacid properties of sucralfate gel dried by microwaves.

The aim of this work was to study the acid neutralization characteristics of microwave-dried sucralfate gel in relation to the water content and physical structure of the substance. Several dried sucralfate gels were compared with humid sucralfate gel and sucralfate nongel powder in terms of neutralization rate and buffering capacity. Humid sucralfate gel and microwave-dried gel exhibited antacid effectiveness. In particular, the neutralization rate of dried gel powders was inversely related to the water content: as the water content of dried powders decreased, the acid reaction rate linearly increased. The relationship was due to the different morphology of dried sucralfate gels. In fact, the porosity of the dried samples increased with the water reduction. However, the acid neutralization equivalent revealed that the dried sucralfate gel became more resistant to acid attack in the case of water content below 42%. Then, the microwave drying procedure had the opposite effect on the reactivity of the aluminum hydroxide component of dried sucralfate gel powders, since the rate of the reaction increased whereas the buffering capacity decreased as the amount of water was reduced.

The effect of residual water on antacid properties of sucralfate gel dried by microwaves.

The aim of this work was to study the acid neutralization characteristics of microwave-dried sucralfate gel in relation to the water content and physical structure of the substance. Several dried sucralfate gels were compared with humid sucralfate gel and sucralfate nongel powder in terms of neutralization rate and buffering capacity. Humid sucralfate gel and microwave-dried gel exhibited antacid effectiveness. In particular, the neutralization rate of dried gel powders was inversely related to the water content: as the water content of dried powders decreased, the acid reaction rate linearly increased. The relationship was due to the different morphology of dried sucralfate gels. In fact, the porosity of the dried samples increased with the water reduction. However, the acid neutralization equivalent revealed that the dried sucralfate gel became more resistant to acid attack in the case of water content below 42%. Then, the microwave drying procedure had the opposite effect on the reactivity of the aluminum hydroxide component of dried sucralfate gel powders, since the rate of the reaction increased whereas the buffering capacity decreased as the amount of water was reduced.

In vitro antimicrobial activity of endodontic pastes with propolis extracts and calcium hydroxide: a preliminary study.

The purpose of this study was to evaluate the antimicrobial activity of two experimental pastes containing propolis extract associated with calcium hydroxide against polymicrobial cultures collected from 16 necrotic and fistulae root canals in primary molars of 4-8-year-old children of both sexes. The agar-well diffusion technique was used to determine the antimicrobial activity of the following pastes: 11.0% ethanolic extract of propolis (EEP) + calcium hydroxide; and 11.0% extract of propolis without ethanol (EP) + calcium hydroxide. EEP, EP and the association of calcium hydroxide and propylene glycol (CHP) was used as the positive control groups, and propylene glycol was used as a negative control group. Friedman and Wilcoxon tests were used to compare the data from the microbial growth inhibition zones (p<0.05). Paste 1 and Paste 2 showed larger growth inhibition zones against microorganisms from root canal samples than CHP (p=0.021 and 0.003, respectively). Paste 2 tended to have larger growth inhibition zones than Paste 1 (p=0.053). The association between propolis and calcium hydroxide was effective in controlling dental infections in vitro.

Effect of residual water content on the physico-chemical properties of sucralfate dried gel obtained by microwave drying.

The purpose of this study was to investigate the physico-chemical characteristics of sucralfate humid gel dried by microwaves, in relation to the residual water content. Differential scanning calorimetry (DSC) allowed for the determination of the water state in sucralfate samples. Fourier-transform infrared (FT-IR) spectroscopy was used to monitor the changes in sucralfate gel structure induced by the microwave drying. A boundary value of total water content for sucralfate gel samples was found at 42% (w/w). Below this value only bound water was present, whereas above this value, the increase in total water was due to free water. In the physical form of gel, the strength of the coordination between sulfate anions and the positively charged aluminum hydroxide was dependent on the residual water content. The study of the sedimentation behavior of water suspensions prepared with dried sucralfate allowed for the evaluation of the retention of gel properties. We found that the microwave drying process affected the sedimentation of sucralfate dried gel suspensions independent of the residual water content: when suspensions were prepared from sucralfate dried gel powders containing more than 42% (w/w) of residual water, the sedimentation ratio was higher than 0.9. The non-gel powder suspension showed a sedimentation ratio of 0.68 +/- 0.02, whereas the sucralfate humid gel suspension did not sediment.

In vitro antimicrobial activity of endodontic pastes with propolis extracts and calcium hydroxide: a preliminary study

The purpose of this study was to evaluate the antimicrobial activity of two experimental pastes containing propolis extract associated with calcium hydroxide against polymicrobial cultures collected from 16 necrotic and fistulae root canals in primary molars of 4-8-year-old children of both sexes. The agar-well diffusion technique was used to determine the antimicrobial activity of the following pastes: 11.0 percent ethanolic extract of propolis (EEP) + calcium hydroxide; and 11.0 percent extract of propolis without ethanol (EP) + calcium hydroxide. EEP, EP and the association of calcium hydroxide and propylene glycol (CHP) was used as the positive control groups, and propylene glycol was used as a negative control group. Friedman and Wilcoxon tests were used to compare the data from the microbial growth inhibition zones (p<0.05). Paste 1 and Paste 2 showed larger growth inhibition zones against microorganisms from root canal samples than CHP (p=0.021 and 0.003, respectively). Paste 2 tended to have larger growth inhibition zones than Paste 1 (p=0.053). The association between propolis and calcium hydroxide was effective in controlling dental infections in vitro.

O objetivo dessa pesquisa foi avaliar a atividade antimicrobiana de duas pastas experimentais, contendo própolis associada a hidróxido de cálcio, contra culturas polimicrobianas coletadas de 16 molares decíduos necrosados e com fístulas extraídos de crianças entre 4 e 6 anos de idade de ambos os sexos. A técnica de difusão em ágar foi utilizada para determinar a atividade antimicrobiana das seguintes pastas: (1) 11,0 por cento extrato etanólico de própolis + hidróxido de cálcio e (2) 11,0 por cento extrato de própolis sem álcool + hidróxido de cálcio. A associação de hidróxido de cálcio com propilenoglicol foi utilizada como o grupo de controle positivo (CHP). Testes estatísticos de Friedman and Wilcoxon foram empregados para comparar dados do crescimento das zonas de inibição (p<0,05). Pasta 1 e Pasta 2 apresentaram zonas de inibição maiores contra os microrganismos coletados dos canais radiculares do que CHP (p=0,021 e 0,003 respectivamente). A Pasta 2 mostrou zonas de inibição um pouco mais largas que a Pasta 1 (p=0,053). A associação entre própolis e hidróxido de cálcio foi efetiva no controle de infecções dentárias in vitro.

Extração assimétrica com a técnica Straight-Wire simplificada: relato de caso clínico / Asymmetric extraction with simplified Straight-Wire technique: case report

Casos assimétricos são muito comuns no cotidiano ortodôntico, nos quais as relações sagitais posteriores são distintas, resultando em um desvio de linha média. Para o tratamento desses casos, deve ser considerados fatores como: idade do paciente, presença de dentes impactados, potencial de crescimento para auxiliar a mecânica ortodôntica, ausências dentárias, faltas de espaço, diastemas e discrepância de Bolton. Em diversos casos é fundamental a realização de extrações assimétricas para a correção ortodôntica. O presente trabalho tem a proposição de relatar um caso clínico de uma paciente leucoderma, de 24 anos de idade, com má oclusão Classe II divisão 1, desvio de linha média superior para a esquerda, impacção do dente 23 e discrepância de modelo negativa. Foi proposto o tratamento ortodôntico utilizando a técnica Straight-Wire Simplificada, com extrações assimétricas dos elementos dentários 23 e 14, mecânica para fechamento de espaço e correção do desvio de linha média. Foram obtidos resultados satisfatórios tanto do ponto de vista oclusal quanto estético.

Influência de fármacos na movimentação dentária induzida / The influence of drugs on orthodontic tooth movement

A Ortodontia está fundamentada na habilidade do profissional em produzir umacontrolada movimentação dos dentes através do osso alveolar, a partir da aplicação da forçaortodôntica. Entretanto, a movimentação ortodôntica pode ser influenciada por vários fatores,dentre eles, o uso de medicamentos. Em vista do exposto, o objetivo deste trabalho foirealizar uma revisão narrativa da literatura sobre a influência de fármacos ou suplementos namovimentação dentária induzida. Como a maior parte dos trabalhos foi realizada com animaise não com humanos e há grande variabilidade entre as metodologias, não se pode afirmarcategoricamente sobre qualquer modificação na movimentação ortodôntica causada poralgum tipo de fármaco que o paciente utilize durante o tratamento ortodôntico. Vislumbra-se,futuramente, atuar na taxa da movimentação ortodôntica com o auxílio de medicamentos.

Orthodontics is based on the professional's ability to produce a controlledteeth movement in alveolar bone through the application of orthodontic force. However, theorthodontic movement may be influenced by several factors, including the use of medicines.Due to it, the aim of this study was to perform a narra tive literature review on the effectsof drugs on experimental tooth movement. As most experimental studies were done withanimais instead of humans and there is a great variability among the methodologies, stetementscannot yet be done about any change in tooth movement caused by some kind ofmedication took by patients during orthodontic treatment. We envision in the future actingon orthodontic tooth movement with the aid of drugs.