Assessment of anesthetic properties and pain during needleless jet injection anesthesia: a randomized clinical trial

Abstract Pain due to administration of local anesthetics is the primary reason for patients' fear and anxiety, and various methods are used to minimize it. This study aimed to measure the degree of pain during administration of anesthesia and determine the latency time and duration of pulpal anesthesia using two anesthetic methods in the maxilla. Materials and Methods: A randomized, single-blind, split-mouth clinical trial was conducted with 41 volunteers who required class I restorations in the maxillary first molars. Local anesthesia was administered with a needleless jet injection system (experimental group) or with a carpule syringe (control) using a 30-gauge short needle. The method of anesthesia and laterality of the maxilla were randomized. A pulp electric tester measured the latency time and duration of anesthesia in the second molar. Visual analogue scale (VAS) was used to measure the degree of pain during the anesthetic method. Data were tabulated and then analyzed by a statistician. The t-test was used to analyze the differences between the groups for basal electrical stimulation. Duration of anesthesia and degree of pain were compared using the Mann-Whitney test. A 5% significance level was considered. Results: There was no statistical difference in the basal electrical stimulation threshold (mA) and degree of pain between the two methods of anesthesia (p>0.05). Latency time was 2 minutes for all subjects. The duration of pulpal anesthesia showed no statistical difference (minutes) between the two methods (p<0.001), with a longer duration for the traditional method of anesthesia (median of 40 minutes). Conclusions: The two anesthetics methods did not differ concerning the pain experienced during anesthesia. Latency lasted 2 minutes for all subjects; the traditional infiltration anesthesia resulted in a longer anesthetic duration compared with the needleless jet injection.

Endoscopic gastric submucosal dissection: experimental comparative protocol between standard technique and Hybrid-Knife(r) / Dissecção endoscópica submucosa gástrica: protocolo experimental comparativo entre a técnica convencional e o Hybrid-Knife(r)

ABSTRACT Background Endoscopic treatment of superficial gastrointestinal tumors is routinely performed, however the advantages and shortcomings of submucosal pressure-jet dissection is still debated. Objective - Aiming to compare this technique with conventional submucosal dissection, a study was designed in pigs. Methods - Areas of the antral mucosa of the stomach with a diameter of 2 cm2 (6 per animal) were marked, and resected by means of the hybrid-knife (experimental technique), and Flush-knife or IT-knife (controls). An ERBE ICC 300 electrosurgical unit was adopted. End-points were procedural time, complications, and quality of the resected specimen. Results - A total of 27 interventions were conducted in five animals. Time spent with the two options was quite short, and similar: 9.5±3.1 vs 8.0±3.0 minutes (P=0.21). Complications didn't differ (three per group, not significant), and removed specimen looked adequate in both circumstances. Conclusion - The hybrid-knife technique is an acceptable alternative to submucosal dissection, showing no difference compared to the standard technique taking into consideration the procedure, the presence of complications and the quality of the resected specimen.

RESUMO Contexto O tratamento endoscópico de tumores gastrointestinais superficiais é realizado rotineiramente, no entanto as vantagens e deficiências da dissecção submucosa com jato de pressão ainda é debatido. Objetivo - Visando comparar esta técnica com dissecção submucosa convencional, um estudo foi realizado em suínos. Métodos - Áreas da mucosa antral do estômago com um diâmetro de 2 cm2 (um total de 6 por animal) foram marcadas, e a ressecção através do hybrid-knife (técnica experimental), e do Flush-knife ou IT-knife (controles). Uma unidade eletro cirúrgica ERBE ICC 300 foi adotada. Os desfechos foram: tempo do procedimento, complicações e qualidade da amostra ressecada. Resultados - Um total de 27 intervenções foram realizadas em cinco animais. O tempo gasto com as duas técnicas foi curto e semelhante: 9,5±3,1 vs 8,0±3,0 minutos (P=0,21). As complicações não diferiram (três por grupo, não significativas), e amostras retiradas foram adequadas em ambas as circunstâncias. Conclusão - A técnica de hybrid-knife é uma alternativa aceitável para dissecção submucosa, demonstrando não haver diferença em comparação à técnica convencional levando em consideração o tempo de procedimento, a presença de complicações e a qualidade da amostra ressecada.

The evaluation of mechanical performance of a jet injection system / 中国医疗器械杂志

In this study, the mechanical properties of a self-made jet injector and a foreign product are tested from three aspects: penetration ability, injection completeness and injection dispersion. Correspondingly, three different experiments are designed and performed: dynamic pressure measurement, injection into silicon rubbers with fixed hardness yet different thickness and injection into polyacrylamide gels with fixed hardness. The results show similar mechanical properties between self-made system and the foreign system. The evaluation of the mechanical performance of jet injectors that consists of penetration ability, injection completeness and injection dispersion can describe the jet injection process effectively.

Development of a novel liquid injection system / 中国医疗器械杂志

A liquid jet injector employs compressed gas or spring to produce a high-velocity stream to deliver liquid drug into human body through skin. There are many clinical jet injection products available, none of which is domestic. A new liquid jet injector is designed based on a comprehensive analysis of the current products. The injector consists of an ejector, trigger and a re-positioning mechanism. The jets characteristics of sample injector are tested, and the results show that the maximum exit pressure is above 15 MPa, a threshold value for penetrating into the skin.

Effect of tetanus toxoid powder needleless injection on the concentration of serum antibody IgG in mice / 药学学报

In this study, a self-designed powder needleless injection system was compared with subcutaneous injection using a needle and syringe to deliver tetanus toxoid (TT) into mice to elicit immunity. First of all, factors influencing the prepartion of TT into powder by being absorbed on aluminium hydroxide were investigated and the micromeritic characters of Al (OH)3-TT powder were observed with optical microscope and laser particle analyzer. The results showed that salt concentration and absorption time had an enhancive effect on drug loading, but the pH value and temperature did not influence the absorption reaction obviously. The absorption reaction was optimized with sodium chloride concentration of 0.4 mol x L(-1) and lasting for 10 min. The average diameter of Al(OH)3-TT powder prepared with conditions optimized above was (60.6 +/- 4.4) microm. The immunization effect of TT was determined through enzyme-linked immunosorbent assay (ELISA) of the concentration of IgG antibody elicited by TT. With delivery of Al(OH)3-TT (of 30 microg TT) by powder needleless injection to mice, the IgG antibody concentration were (6.19 +/- 0.52) and (10.70 +/- 0.78) U x L(-1) after immunization of 4 and 8 weeks, respectively, while the values were (4.25 +/- 0.58) and (7.48 +/- 0.57) U x L(-1) by subcutaneous injection (of 20 microg TT) using a needle and syringe. The results suggested that the self-designed powder needleless injection of Al(OH)3-TT was comparable to subcutaneous injection with a good immunity.

Bioavailability and influncing factors of self-designed powder needleless injection system on rabbits / 药学学报

Powder needleless injection (PNI) is a novel method for administration of drugs, especially proteins and peptides. In this study, fluoresceinsodium was selected as model drug to evaluate and optimize the bioavailability of PNI on rabbits. The determination method was HPLC-FLD. The analyzing time of the method was within 3 minutes. A linear relationship of fluoresceinsodium was good between 0.0047 and 0.1872 microg x mL(-1) and the recovery of the method was larger than 97.6% (RSD < 3.6%). With the orthogonal experiments, the influence on PNI of several factors was compared. The model of the injector was the most important factor to enhance the bioavailability while gas pressure and drug diameter had positive correlation with both bioavailability and damage on skin. A condition of PNI, injector model C3, gas pressure of 4 MPa and drug diameter of 90-125 microm, was carried out and the bioavailability of self-designed PNI system was 34.9% in compare of the result (33%) of foreign correspording product in some degree. However, the mainly applicable drug types of PNI are proteins and peptides which is of high cost. So the self-designed PNI system needs to be improved.

Avaliaçäo da resistência ao cisalhamento em dentina de cimentos de ionômero de vidro convencional e modificado e duas resinas compostas, empregando-se três sistemas adesivos e duas técnicas de secagem da dentina / Evaluate the shear bond strength on dentine of conventional and modified glass ionomer cements, with the use of three adhesive systems and two drying techniques

A influência de adesivos e da umidade dentinária na resistência ao cisalhamento da uniäo entre dentina e materiais restauradores diretos foi avaliada neste trabalho. Os materiais restauradores testados foram: um cimento de ionômero de vidro convencional (Chelon-fil - ESPE), um cimento de ionômero de vidro modificado com resina (Vitremer - 3M), uma resina composta modificada com poliácidos (Dyract - Dentsply) e uma resina composta (TPH Dentsply). No trabalho foram utilizados 240 pré-molares e molares humanos extraídos, que tiveram uma de suas superfícies proximais desgastadas até se obter uma superfície plana em dentina, sobre a qual foram aplicados os sistemas adesivos e os materiais restauradores. Os espécimes foram divididos em 4 grupos experimentais. No grupo 4.3.1, a dentina foi condiconada com o adesivo próprio indicado pelo fabricante do material restaurador; no grupo 4.3.2., a dentina foi condicionada com um sistema adesivo experimental Gluma C; no grupo 4.3.3, a dentina foi condicionada com o sistema adesivo Prime & Bond 2.0 (Dentsply); e no grupo 4.3.4, a dentina foi condicionada com o sistema adesivo Scotchbond MP (3M). A técnica de secagem da dentina utilizada foi jato de ar por 5 segundos, considerada técnica seca, e lenço de papel aplicado duas vezes sobre a dentina, considerada técnica úmida. Os espécimes foram confeccionados com os materiais restauradores e os sistemas adesivos utilizados de acordo com as instruçöes dos fabricantes, armazenados em água por 24 horas e testados em máquina universal de testes KRATOS. A análise estatística mostrou que a resina composta Dyract, a melhor combinaçäo foi a do adesivo próprio na técnica úmida, que apresentou o maior resultado, de 23,36MPa. Os resultados com cimento Vitremer, utilizando-se os sistemas adesivos Prime & Bond 2.0 e o adesivo experimental Gluma C, foram de 16,45MPa e 13,58 MPa, respectivamente. Esses adesivos melhoraram significantemente a adesäo quando comparados com o adesivo próprio. Com relaçäo à técnica de secagem da dentina, a técnica úmida foi significantemente melhor que a técnica seca (p<0,01)

Contraceptive efficacy of Depot Provera jet-injected into the cervix.

Depot-medroxy progesterone acetate (DMPA) was jet deposited into the uterus/cervix of rats, rabbits and rhesus monkeys with the help of a modified jet injection apparatus. Since the drug was delivered under pressure, it was distributed deep into the muscular layers around the place of deposition. After one deposition the drug acted as an effective contraceptive for a period of three months. The merits of this delivery technique are discussed.