Duration Of Anesthetic Effect Research Articles

Evaluation of acceptance and preference of topical lidocaine application versus articaine injection anesthesia after nonsurgical periodontal treatment: A randomized clinical trial.

To compare acceptance and preference of topical lidocaine gel anesthesia with articaine injection anesthesia in patients with moderate periodontitis undergoing scaling and root debridement. Ninety-one patients completed this randomized multicenter split-mouth controlled study and underwent two separate periodontal treatment sessions on different days, one with a topical intrapocket lidocaine gel application and the other with an articaine injection anesthesia in a different order depending on randomization. Parameters measured were the patients' preference for topical lidocaine gel anesthesia or injection anesthesia with articaine (primary efficacy criterion), their maximum and average pain, and their intensity of numbness as well as experience of side effects; the probing depth; and the dentists' preference and their evaluations of handling/application, onset and duration of anesthetic effect, and patient compliance. After having experienced both alternatives, 58.3% of the patients preferred the topical lidocaine gel instillation into the periodontal pockets. The safety profile of the lidocaine gel differed positively from the safety profile of articaine injection in type and frequency of adverse drug reactions. The dentists' acceptance and preference regarding either anesthetic method studied were balanced. Instillation of lidocaine gel into the periodontal pocket is a preferred alternative to injection anesthesia for most of the patients and an equivalent alternative for dentists in nonsurgical periodontal therapy.

Evaluation of Onset and Duration Period of Pulpal Anesthesia on Articaine, Buffered Articaine, Lignocaine and Buffered Lignocaine in Inferior Alveolar Nerve Block

Context: Pain is one of the most commonly experienced symptoms in dentistry, and managing pain is of greater importance during dental treatment. Local anesthetics are chemicals that block nerve conduction in a specific, temporary and reversible manner, without affecting the patient’s consciousness. Aims: The aim of this study is to evaluate the anesthetic efficacy of buffered lignocaine, buffered articaine, unbuffered lignocaine and unbuffered articaine in terms of latency (onset of anesthetic effect), duration of anesthetic effect during extraction of mandibular teeth following standard inferior alveolar nerve block. Settings and Design: This study was conducted at Department of Oral and Maxillofacial Surgery, Saveetha University, Chennai from November 2013 to November 2015. Methods and Materials: This study compares the anesthetic efficacy of 4% articaine, 2% lignocaine, 4% buffered articaine and 2% buffered articaine with epinephrine. Onset, duration of anesthetic effect was compared. Statistical analysis used: ANOVA Results: Total number of patients were 272. These patients were equally divided into 4 groups, each group containing 68 patients.THE anova test shows that significant difference between the groups, the mean value shows the group 4 is better than the other 3 groups. Conclusion: We conclude that 4% articaine has faster onset when compared to the other three group. Buffered lignocaine had significantly longer duration when compared to the other groups. This can be explained based on its different chemical structure, liposolubility, increased protein binding ability, diffusion in soft tissue and increased pulpal anesthesia

Age and Sex Variation in the Duration of Action and Corneal Touch Threshold (CTT) following Instillation of 0.5% Topical Ophthalmic Proparacaine and Tetracaine Hydrochlorides.

Purpose We investigated the effect of age and sex on corneal touch threshold (CTT) and duration of action following administration of 0.5% topical ophthalmic proparacaine and tetracaine hydrochlorides. Methods A prospective, randomized, subject-masked, crossover study design was used. Two hundred and forty human volunteers were enrolled in the study. Corneal touch threshold (CTT) was determined using a Cochet-Bonnet esthesiometer. CTT was measured every 15 seconds for the first 1-minute and at 5-minute intervals subsequently for a period of 40 minutes after the application of each anesthetic. CTT and duration of action of the ophthalmic solutions were tested for statistical significance using repeated measures ANOVA. Results The total duration of effect was 20 minutes for females and 25 minutes for males for both anesthetics. The total duration of the effect of both solutions decreased with increasing age; however, elderly participants had the longest duration (5 minutes) of the maximal effect (minimum CTT) of the two ophthalmic preparations. There was a significant influence of sex, F (2.39, 569.65) = 2.86, p=0.04; F (3.48, 828.19) = 4.41, p=0.003, and age, F (4.78, 566.18) = 8.97, p < 0.001; F (7.19, 852.56) = 20.55, p < 0.001 on CTT following application of proparacaine hydrochloride and tetracaine hydrochloride, respectively. Conclusion CTT and duration of anesthetic effect after instillation of 1 drop of 0.5% proparacaine hydrochloride and 0.5% tetracaine hydrochloride vary based on sex and age.

A randomized controlled trial of minor hand surgeries comparing wide awake local anesthesia no tourniquet and local anesthesia with tourniquet

IntroductionEpinephrine and sodium bicarbonate (NaHCO3) used in wide-awake local anesthesia no tourniquet (WALANT) affect many areas such as hemostasis, injection pain, anesthetic effect and others. However, few clinical trials have focused on injection pain and the duration of anesthetic effect, and no prospective studies have reported the benefits of WALANT post operation. This study compared WALANT with conventional local anesthesia with tourniquet in minor hand surgeries, and aimed to answer following questions: (1) Does WALANT have enough benefits for injection pain and duration of anesthetic effect?; (2) How does WALANT affect postoperative management (such as postoperative pain and use of analgesics)?; (3) How satisfied are the patients with the surgery? HypothesisWe hypothesized that WALANT had advantages in injection pain, duration of anesthetic effect, and postoperative management compared to conventional local anesthesia. Materials and methodsThe present study is designed as a randomized prospective one center study. This study included 185 patients who received surgical treatment for the diagnosis of carpal tunnel syndrome, trigger finger, or de Quervain's disease between 2017 and 2019. We randomly allocated the patients to either the WALANT group or the conventional group. We inquired and recorded patients’ injection pain, duration of anesthetic effect, postoperative pain, the use of analgesics, and satisfaction with the surgery. ResultsThe injection pain was significantly lower in the WALANT group in all procedures (p<0.001). The duration of anesthetic effect was significantly longer in the WALANT group in all procedures (p<0.001). As for the postoperative management of all procedures, the pain score was significantly lower in the WALANT group until the first day after surgery, with the biggest difference at 6hours after surgery. The use of analgesics was significantly lower in the WALANT group until the second day after surgery. Satisfaction with surgery was significantly higher in the WALANT group in all procedures: A1 pulley release (p=0.026), 1st extensor retinaculum (p=0.045), and carpal tunnel release (p=0.003). DiscussionOur study showed better results in WALANT than in the conventional method, with no tourniquet pain, lower injection pains, longer anesthetic duration, and less postoperative pain. It provided patients with great satisfaction. In addition, WALANT has the potential benefits of no time limit due to tourniquet pain and long anesthetic effect. Therefore, WALANT is comfortable and cost effective, and could be a good alternative to conventional local lidocaine anesthesia. Level of evidenceII.

Un essai contrôlé randomisé comparant l’anesthésie locale sur malade éveillé sans garrot et l’anesthésie locale avec garrot pour les chirurgies mineures de la main

IntroductionEpinephrine and sodium bicarbonate (NaHCO3) used in wide-awake local anesthesia no tourniquet (WALANT) affect many areas such as hemostasis, injection pain, anesthetic effect and others. However, few clinical trials have focused on injection pain and the duration of anesthetic effect, and no prospective studies have reported the benefits of WALANT post operation. This study compared WALANT with conventional local anesthesia with tourniquet in minor hand surgeries, and aimed to answer following questions: (1) Does WALANT have enough benefits for injection pain and duration of anesthetic effect? (2) How does WALANT affect postoperative management (such as postoperative pain and use of analgesics)? (3) How satisfied are the patients with the surgery? HypothesisWe hypothesized that WALANT had advantages in injection pain, duration of anesthetic effect, and postoperative management compared to conventional local anesthesia. Materials and methodsThe present study is designed as a randomized prospective one center study. This study included 185 patients who received surgical treatment for the diagnosis of carpal tunnel syndrome, trigger finger, or de Quervain's disease between 2017 and 2019. We randomly allocated the patients to either the WALANT group or the conventional group. We inquired and recorded patients’ injection pain, duration of anesthetic effect, postoperative pain, the use of analgesics, and satisfaction with the surgery. ResultsThe injection pain was significantly lower in the WALANT group in all procedures (p<0.001). The duration of anesthetic effect was significantly longer in the WALANT group in all procedures (p<0.001). As for the postoperative management of all procedures, the pain score was significantly lower in the WALANT group until the first day after surgery, with the biggest difference at 6hours after surgery. The use of analgesics was significantly lower in the WALANT group until the second day after surgery. Satisfaction with surgery was significantly higher in the WALANT group in all procedures: A1 pulley release (p=0.026), 1st extensor retinaculum (p=0.045), and carpal tunnel release (p=0.003). DiscussionOur study showed better results in WALANT than in the conventional method, with no tourniquet pain, lower injection pains, longer anesthetic duration, and less postoperative pain. It provided patients with great satisfaction. In addition, WALANT has the potential benefits of no time limit due to tourniquet pain and long anesthetic effect. Therefore, WALANT is comfortable and cost effective, and could be a good alternative to conventional local lidocaine anesthesia. Level of evidenceII.

Clinical evaluation of efficacy of transcortical anesthesia for the extraction of impacted mandibular third molars: a randomized controlled trial.

BackgroundThis study aimed to compare the pain levels during anesthesia and the efficacy of the QuickSleeper intraosseous (IO) injection system and conventional inferior alveolar nerve block (IANB) in impacted mandibular third molar surgery.MethodsThis prospective randomized clinical trial included 30 patients (16 women, 14 men) with bilateral symmetrical impacted mandibular third molars. Thirty subjects randomly received either the IO injection or conventional IANB at two successive appointments. A split-mouth design was used in which each patient underwent treatment of a tooth with one of the techniques and treatment of the homologous contralateral tooth with the other technique. The subjects received 1.8 mL of 2% articaine. Subjects' demographic data, pain levels during anesthesia induction, tooth extractions, and mouth opening on postoperative first, third, and seventh days were recorded. Pain assessment ratings were recorded using the 100-mm visual analog scale. The latency and duration of the anesthetic effect, complications, and operation duration were also analyzed in this study. The duration of anesthetic effect was considered using an electric pulp test and by probing the soft tissue with an explorer.ResultsThirty patients aged between 18 and 47 years (mean age, 25 years) were included in this study. The IO injection was significantly less painful with lesser soft tissue numbness and quicker onset of anesthesia and lingual mucosa anesthesia with single needle penetration than conventional IANB. Moreover, 19 out of 30 patients (63%) preferred transcortical anesthesia. Mouth opening on postoperative first day was significantly better with intraosseous injection than with conventional IANB (P = 0.013).ConclusionThe IO anesthetic system is a good alternative to IANB for extraction of the third molar with less pain during anesthesia induction and sufficient depth of anesthesia for the surgical procedure.

Comparative study of articaine and lidocaine for third molar surgery

Background: This study aims to compare the anesthetic efficacy, postoperative pain, hemorrhage &amp; dry sock incidence of articaine 4% versus lidocaine 2% in inferior alveolar nerve block during impacted lower third molar surgery. Method: A prospective randomized study was conducted on 20 subjects planned for elective surgical removal of bilateral impacted mandibular with similar difficulty indices. A single operator performed all surgeries on basis using 4% articaine or 2% lidocaine as an anesthetic agent and with the same concentration of vasoconstrictor (epinephrine 1:100,1000). Latency, duration of anesthetic effect, intra and post surgical pain experiences, hemorrhage &amp; dry socket occurrences were evaluated with respect to the type of anesthetia. A visual analog scale was used to score pain.Data were analyzed by descriptive statistics, repeated measures ANOVA, Wilcoxon and McNemar’s test (a=0.05). Results: Latency, Intra &amp; Postoperative pain and hemorrhage showed clinical differences in favor of articaine, though statistical significance was not reached. In turn, the mean duration of anesthetic for articain was much extended and showed statistically significant difference. Dry socket incidence consisted of two occurrences (5 %) and those two only occurred in Lidocain group. Conclusion: although 4% articaine offers better pharmacological performance than 2% lidocaine, both articaine and lidocaine have demonstrated adequate, negligible differences and acceptable clinical profiles. For this reason, their use in oral surgery should remain of the professional preference who will evaluate their use base on the necessary surgical time.

Local Anaesthesia in Dentistry- Lignocaine too Good or Articaine the Best?

Local anaesthesia is key to painless dental surgical, endodontic and operative procedures. Lignocaine is the gold standard for pain management in dentistry since ages. But, articaine is more potent than lignocaine in attaining infiltration local anaesthesia with low toxicity. Currently, articaine is extensively utilized in dentistry however infrequently used in children. Nevertheless, for selection of local anaesthetic; potency, latency, and duration of anaesthetic effect, pharmacokinetics and toxicity of anaesthetics should be evaluated. Therefore, we will discuss whether “lignocaine is too good or articaine is the best” to accomplish complete pain control with safety and efficacy.

Benzocaine loaded solid lipid nanoparticles: Formulation design, in vitro and in vivo evaluation of local anesthetic effect.

The aim of the present work is the development and evaluation of solid lipid nanoparticles (SLNs) as carrier system for topical delivery of benzocaine (BZC) improving its local anesthesia aiming to produce a fast acting and long lasting topical formulation. BZC loaded SLNs were prepared using a full factorial design to study the influence of the type of polyoxyethylene sorbitan ester surfactants as well as their concentration as independent variables on the particle size, entrapment efficacy and zeta potential selected as dependent variables. Design of experiment (DOE) and the analysis of variance (ANOVA) were conducted to assess the optimization of the developed formulations. The results indicated that the fatty acid chain length of tested surfactants and their concentration had a significant effect on the studied responses. The optimized formulations were spherical in shape of mean particle diameters<350 nm with negatively charged surface <-20mV. Particles were characterized using differential scanning calorimetry and X-ray powder diffraction confirming the amorphous nature and the uniformity of drug inclusion in the lipid matrix. Optimized BZC-SLNs were incorporated into hydrogels characterized by a pseudoplastic non-Newtonian behavior. In vitro release study revealed an apparently biphasic release process with sustained release profile following Higuchi kinetics. BZC loaded SLNs hydrogels showed more potent anesthetic effect compared to BZC hydrogel evaluated using tail-flick analgesimeter, confirming significant improvement in both the intensity and duration of anesthetic effect. The above results proved that SLNs represent good candidates to encapsulate BZC improving its therapeutic efficacy for the topical treatment of pain.

Anaesthetic digital block with epinephrine vs. tourniquet in ingrown toenail surgery: a clinical trial on efficacy

Current evidence shows that anaesthetic digital block with epinephrine is safe in surgical selected patients. There are no controlled studies that have examined the efficacy of local anaesthesia with vasoconstrictor in chemical matricectomy without using tourniquet to control bleeding. A controlled, prospective and randomized study was conducted to examine primarily the rate of recurrence after segmental phenolization matricectomy with anaesthetic digital block with epinephrine vs. tourniquet. As secondary aims, duration of anaesthetic effect, post-operative bleeding and pain were analysed in both groups. Forty-four healthy subjects with ingrown hallux nails (70 toes) were enrolled. A total of 34 toes were anaesthetized with a solution of 2% mepivacaine with (1 : 100,000) epinephrine and operated without tourniquet (experimental group) vs. 36 toes anesthetized with a solution of 2% mepivacaine without epinephrine and operated with tourniquet (control group). There was no statistically significant difference in recurrence rates (P = 0.478). Post-operative bleeding was significantly higher in the group with anaesthetic digital block without vasoconstrictor and with tourniquet (P = 0.001). Anaesthetic effect was higher in the group with anaesthetic digital block with vasoconstrictor and without tourniquet (P = 0.001). No post-operative complications occurred in any of the treatment groups. The use of local anaesthetic with vasoconstrictor to perform chemical matricectomy likely to be an effective procedure to reduce the disadvantages of using digital tourniquet (post-operative bleeding and lower anaesthetic effect) without increasing the risk of recurrence. The addition of epinephrine may reduce the need for a tourniquet and produce better and longer perioperative pain control.

Comparative study of the anesthetic efficacy of 4% articaine versus 2% lignocaine in the inferior alveolar nerve block during the surgical extraction of impacted mandibular third molars

Background: Pain control through the truncal block of the inferior alveolar nerve is one of the locoregional anesthetic techniques most widely used in oral surgery, affording comfort and safety for both the patient and operator when used correctly. Aim: To compare the anesthetic efficacy of both 4% articaine and 2% lignocaine with epinephrine in the truncal block of the inferior alveolar nerve during surgical removal of the impacted mandibular third molars. Materials and Methods: A randomized, double-blind, clinical trial was conducted of 360 patients programmed for the surgical extraction of symmetrical lower third molars in the context of the Master of Oral Surgery and Implantology (Saveetha Dental College, Saveetha University, Chennai, India). Following the obtainment of informed consent, two operators performedsurgery on an extemporaneous basis, using as local anesthetic 4% articaine or 2% lignocaine, with the same concentration of a vasoconstrictor (epinephrine 1:100,000). The study variables for each anesthetic were: Latency (time to action) and duration of anesthetic effect, the need of reanesthetizing the surgical zone, and intraoperative pain intensity measured objectively using the Visual Analog Scale (VAS) and Faces Pain Scale (FPS). Data were analyzed using the Independent t -test and Chi-square test. Results: A statistically significant difference ( P P Conclusion: We conclude that 4% articaine has better anesthetic efficacy as compared to 2% lignocaine. This can be explained based on its different chemical structure, liposolubility, increased protein-binding ability, diffusion in soft tissue, and increased pulpal anesthesia.

The effect of buffering on pain and duration of local anesthetic in the face: A double-blind, randomized controlled trial

The acidity of lidocaine preparations is believed to contribute to the pain of local anesthetic injection. To investigate the effect of buffering lidocaine on the pain of injection and duration of anesthetic effect. A double-blind, randomized trial involving 44 healthy volunteers was conducted. The upper lip was injected with a solution of: lidocaine 1% (Xylocaine, AstraZeneca, Canada, Inc) with epinephrine; and lidocaine 1% with epinephrine and 8.4% sodium bicarbonate. Volunteers reported pain of injection and duration of anesthetic effect. Twenty-six participants found the unbuffered solution to be more painful. Fifteen participants found the buffered solution to be more painful; the difference was not statistically significant. Twenty-one volunteers reported duration of anesthetic effect. The buffered solution provided longer anesthetic effect than the unbuffered solution (P=0.004). Although buffering increased the duration of lidocaine's anesthetic effect in this particular model, a decrease in the pain of the injection was not demonstrated, likely due to limitations of the study.

Evaluation of the anaesthetic properties and tolerance of 1:100,000 articaine versus 1:100,000 lidocaine. A comparative study in surgery of the lower third molar

Objectives: To evaluate the anaesthetic properties and tolerance of articaine versus lidocaine at equal vasoconstrictor concentration. Study Design: A total of 96 male and female patients who underwent surgical treatment of the lower third molar participated. Patients were randomly assigned to articaine hydrochloride with epinephrine 1:100,000 and lidocaine hydrochloride with epinephrine 1:100,000. The variables analysed were latency period, duration of anaesthetic effect, tolerance and adverse reactions. Results: Both the latency period and the duration of anaesthetic effect were greater for articaine, although the differences were not statistically significant. Latency: mean difference of 2.70 ± 2.12 minutes (95%CI of -1.51 minutes - 6.92 minutes). Duration: mean difference of -33 minutes 5 seconds ± 31 minutes (95% CI -1 hour 35 minutes - 29 minutes). There were 4 adverse events that did not require the patients to be withdrawn from the study. Conclusions: The anaesthetics in this study have very similar properties for use in surgery and have demonstrated a good safety and tolerability profile Key words: Articaine, lidocaine, vasoconstrictor, adverse reactions.

A prospective, randomized, triple-blind comparison of articaine and bupivacaine for maxillary infiltrations

Objectives: To compare the clinical anesthetic efficacy of 0.5% bupivacaine and 4% articaine (both with 1:200.000 adrenaline) for anterior maxillary infiltration in healthy volunteers. Material and methods: A triple-blind split-mouth randomized clinical trial was carried out in 20 volunteers. A supraperiosteal buccal injection of 0.9 ml of either solution at the apex of the lateral incisor was done in 2 appointments separated 2 weeks apart. The following outcome variables were measured: latency time, anesthetic efficacy (dental pulp, keratinized gingiva, alveolar mucosa and upper lip mucosa and tissue) and the duration of anesthetic effect. Hemodynamic parameters were monitored during the procedure. Results: Latency time recorded was similar for both anesthetic solutions (p>0.05). No statistically significant differences were found in terms of anesthetic efficacy for dental pulp, keratinized gingiva or alveolar mucosa. Articaine had a significant higher proportion of successful anesthesia at 10 minutes after infiltration in lip mucosa and lip skin (p=0.039). The duration of anesthesia was 336 minutes for bupivacaine and 167 minutes for articaine. (p<0.001). No significant hemodynamic alterations were noted during the procedure. Conclusions: Articaine and bupivacaine exhibited similar anesthetic efficacy for maxillary infiltrations. The duration of anesthesia was longer with the bupivacaine solution, but lip anesthesia was better with articaine. Key words:Articaine, bupivacaine, maxillary, infiltrative anesthesia, long-acting anesthetics.

Comparative study between manual injection intraosseous anesthesia and conventional oral anesthesia

Objective: To compare intraosseous anesthesia (IA) with the conventional oral anesthesia techniques. Materials and methods: A simple-blind, prospective clinical study was carried out. Each patient underwent two anesthetic techniques: conventional (local infiltration and locoregional anesthetic block) and intraosseous, for res-pective dental operations. In order to allow comparison of IA versus conventional anesthesia, the two operations were similar and affected the same two teeth in opposite quadrants. Results: A total of 200 oral anesthetic procedures were carried out in 100 patients. The mean patient age was 28.6±9.92 years. Fifty-five vestibular infiltrations and 45 mandibular blocks were performed. All patients were also subjected to IA. The type of intervention (conservative or endodontic) exerted no significant influence (p=0.58 and p=0.62, respectively). The latency period was 8.52±2.44 minutes for the conventional techniques and 0.89±0.73 minutes for IA – the difference being statistically significant (p<0.05). Regarding patient anesthesia sensation, the infiltrative techniques lasted a maximum of one hour, the inferior alveolar nerve blocks lasted between 1-3 hours, and IA lasted only 2.5 minutes – the differences being statistically significant (p≤0.0000, Φ=0.29). Anesthetic success was recorded in 89% of the conventional procedures and in 78% of the IA. Most patients preferred IA (61%) (p=0.0032). Conclusions: The two anesthetic procedures have been compared for latency, duration of anesthetic effect, anesthetic success rate and patient preference. Intraosseous anesthesia has been shown to be a technique to be taken into account when planning conservative and endodontic treatments. Key words: Anesthesia, intraosseous, oral anesthesia, Stabident®, infiltrative, mandibular block.

New “drug-in cyclodextrin-in deformable liposomes” formulations to improve the therapeutic efficacy of local anaesthetics

The combined approach of cyclodextrin complexation and entrapment in liposomes was investigated to develop a topical formulation of local anaesthetics. For both benzocaine (BZC) and butamben (BTM), hydroxypropyl-β-cyclodextrin (HPβCD) was a better partner than βCD; drug–HPβCD coevaporated products showed the best solubility and dissolution properties, and were selected for loading into liposomes. Addition of stearylamine to the phosphatidylcholine–cholesterol mixture of the vesicle bilayer allowed obtainment of deformable liposomes with improved permeation and in vivo drug anaesthetic effect ( P < 0.05). Double-loaded deformable liposomes were obtained by adding the drug–HPβCD complex at its maximum aqueous solubility in the vesicles hydrophilic phase, and the remaining amount up to 1% as free drug in the lipophilic phase. The properties of double-loaded liposomes were compared with those of classic single-loaded ones, obtained by adding 1% free drug in the aqueous or lipophilic phase of the vesicles. Size, charge, morphology and entrapment efficiency of the different batches were investigated, respectively, by light scattering, confocal laser scanning microscopy and dialysis, while their therapeutic efficacy was evaluated in vivo on rabbits. For both drugs, double-loaded liposomes, exploiting the favourable effects of drug–CD complexation, allowed a significant ( P < 0.05) enhancement of intensity and duration of anaesthetic effect with respect to those single-loaded.

Liposomal formulations of prilocaine: effect of complexation with hydroxypropyl-ß-cyclodextrin on drug anesthetic efficacy

A combined strategy, based on cyclodextrin complexation and loading in liposomes, has been investigated to develop a new delivery system with improved therapeutic activity of the local anesthetic, prilocaine (PRL). In order to evaluate the actual effectiveness and advantages of this approach compared to the traditional drug-in-liposome one, four different liposomal formulations were prepared: (1) liposomes loaded with PRL base as complex with hydroxypropyl-β-cyclodextrin (HP CD) in the aqueous phase; (2) liposomes loaded with PRL hydrochloride in the aqueous phase; (3) liposomes loaded with PRL base in the lipophilic phase; and (4) “double-loaded” liposomes, containing free PRL base in the membrane bilayer and its HP CD complex in the aqueous compartment. All batches were characterized for particle size, charge, deformability, and entrapment efficiency from using, respectively, light scattering, extrusion, and dialysis techniques, while the anesthetic effect was evaluated in vivo on Guinea pigs, according to the test of dorsal muscle contraction. All drug liposomal dispersions showed enhanced analgesic duration with respect to the corresponding aqueous solutions, but significant differences were observed between the different formulations. In particular, cyclodextrin complexation not only allowed an efficient encapsulation of PRL base in the aqueous vesicle core, but also increased the anesthetic effect duration and reduced the initial lag time, in comparison with the corresponding formulations containing, respectively, free PRL in the lipophilic phase or PRL hydrochloride in the aqueous vesicle core. The technique of double loading was the most effective, giving rise to the shortest onset time and longest duration of anesthetic effect.

Evaluation of anesthetic effect of ropivacaine in surgery of chronic periapical lessions

Ropivacaine is used in orthopedcs, gyneacology, surgery, ophtamology, whereas experience about its usage in dentistry is still limited. The aim of this research was to compare the anesthetic effect between local anesthetics ropivacaine and bupivacaine, in surgical disposals of chronical periapical lessions in maxilla. The study included the patients that had indications for surgical removal of chronical periapical lessions at one of the frontal teeth of upper jaw. The total total number of examinees was 60, and they were devided in two groups. Ropivacaine chloride (0.75%) was used as a local anesthetic in one group (Naropin 0.75%; Astra Zeneca), and in the other one bupivacaine chloride (0.5%) (Vexelit 0.5%; Zdravlje). The authors applied 1.8 ml of block anesthesia for the n. infraorbitalis (intra-oral approach) as well as 0.2 ml of the local anesthetic from the palatine side for the final branches of N. nasopalatinus in order to observe the following anesthetic parameters. (I) Beginning of anesthesia was followed by the appearence of upper lip numbness. (II) Pain rating scale according to Sisk was used for the objective measurement of the anesthesia quality. (III) The pain intensity during the intervention was measured by visual analogous scale, on which the patient denoted the intensity of pain he had felt during the intervention. (IV) Duration of anesthetic effect--it is followed by soft tissues numbness. After the ropivacaine application anesthesia effect started in 1.57 min. and after the usage of bupivacaine in 1.67 min. The mean duration of soft tissue numbness after the application of ropivacaine was 321 minutes. Bupivacaine had a shorter anesthetic effect--296.5 minutes. The quality of anesthesia after the usage of ropivacaine was assessed by the surgeons with average mark--1.76. Interventions in which this anesthetic was used were performed with minimal pain and without additional anesthesia. The quality of anesthesia after the usage of bupivacaine (3.03) was statistically much worse (p < 0.01) in comparison to ropivacaine. In visual analogous scale where patients denoted the intensity of pain during the intervention with ropivacaine the marked average value was 30.1 mm while the average value with usage of bupivacaine was 41.7 mm. The patients from the control group, where bupivacaine was used, had much stronger pain, statistically significant (p < 0.05) in comparison to the group where ropivacaine was used. Our results show that the quality of anesthesia that was attained with 0.5% bupivacaine was much worse than the quality of anesthesia after the application of 0.75% ropivacaine. Ropivacaine has a potential to replace bupivacaine completely in cases when there is the indication for its usage in oral surgery (longlasting intervention, interventions followed by intensive postoperational pain, nerve blockade).

Hyaluronidase Increases the Duration of Mepivacaine in Inferior Alveolar Nerve Blocks

To evaluate the duration of the effect of mepivacaine when hyaluronidase is injected immediately prior to the end of pulpal anesthesia. Forty bilateral, symmetrical third molar surgeries were performed in 20 healthy patients. Inferior alveolar nerve block was induced using 2.8 mL 2% mepivacaine with epinephrine. Hyaluronidase (75 turbidity-reducing units) or a placebo was injected 40 minutes after the beginning of pulpar anesthesia (randomized and double-blind trial). The duration of effect in the pulpal and gingival tissues was evaluated by response to painful electrical stimuli applied to the adjacent premolar, and by mechanical stimuli (pin prick) to the vestibular gingiva, respectively. In both tissues, the duration of anesthetic effect with hyaluronidase was longer (P < .01) than with the placebo. Hyaluronidase increases the duration of mepivacaine in inferior alveolar nerve blocks.

Duration of corneal anesthesia following topical administration of 0.5% proparacaine hydrochloride solution in clinically normal cats

To determine duration of corneal anesthesia following topical administration of 0.5% proparacaine hydrochloride solution in domestic shorthair (DSH) cats. 20 clinically normal DSH cats. Baseline corneal touch threshold (CCT) was established by use of a Cochet-Bonnet aesthesiometer. Treatment consisted of a single 50-microL topical application of an ophthalmic preparation of 0.5% proparacaine solution to a randomly selected eye of each cat. The corneal touch threshold was assessed 1 and 5 minutes after application to the cornea and at 5- minute intervals thereafter for 60 minutes. Corneal sensitivity, as determined by Cochet-Bonnet aesthesiometry, was significantly reduced from baseline for 25 minutes following topical administration of ophthalmic proparacaine. Maximal anesthetic effect lasted 5 minutes. As determined by Cochet-Bonnet aesthesiometry, duration of anesthetic effects on the cornea induced by a single topical application of an ophthalmic preparation of 0.5% proparacaine solution in DSH cats is considerably shorter than the reported duration of corneal anesthesia in dogs.