4% articaine buccal infiltration versus 2% lidocaine inferior alveolar nerve block for emergency root canal treatment in mandibular molars with irreversible pulpits: a randomized clinical study.

AIM: To compare the anaesthetic efficacy of inferior alveolar nerve blocks (IANB) with 1.8 mL of 2% lidocaine (LI) to a buccal infiltration (BI) with 1.8 mL of 4% articaine (AR), both with 1 : 100 000 epinephrine, in patients with symptomatic irreversible pulpits in a randomized controlled trial. METHODOLOGY: Volunteers presenting at the Emergency Centre (FOP-UNICAMP) were randomly divided into two groups (30 for AR and 20 for LI). Operator and patient were not blinded. Success was recorded when complete pain-free treatment was achieved after a single injection (IANB or BI) or when one supplemental injection was needed for emergency endodontic procedures. Success rate of supplemental injection was evaluated between and within groups using Fisher's exact test and chi-square test. RESULTS: A higher success rate (P = 0.03/Fisher's exact test) was observed with AR (40%) than with LI (10%). No significant difference was found when a single injection plus one supplemental injection was compared between groups (P = 1.0; AR = 70%; LI = 80%). However, supplemental injection increased the anaesthetic success rates (AR, P = 0.04; LI, P = 0.0001) within groups. CONCLUSIONS: Single anaesthesia techniques (IANB or BI) were not able to achieve pain-free emergency endodontic treatment. Supplemental anaesthetic techniques should be considered prior to treatment procedures in order to increase success rate (consort: registration number - NCT01912755/Fapesp: #2009/10834-4).

Anaesthetic efficacy of bupivacaine 2-hydroxypropyl-ß-cyclodextrin for dental anaesthesia after inferior alveolar nerve block in rats.

Bupivacaine is a long-acting local anaesthetic that is widely used in medicine and dentistry. The duration and intensity of its sensory blockade in animal models is increased by its inclusion in complexes with cyclodextrins. The aim of the present study was to evaluate the anaesthetic efficacy of bupivacaine 2-hydroxypropyl-ß-cyclodextrin (HPßCD) inclusion complex for dental anaesthesia after inferior alveolar nerve block in rats. Thirty rats were each given an injection close to the mandibular foramen of 0.2ml of one of the following formulations: 0.5% bupivacaine alone; 0.5% bupivacaine with 1:200,000 epinephrine; and 0.5% bupivacaine-HPßCD inclusion complex (bupivacaine-HPßCD). The other sides were used as controls, with either 0.9% saline or anaesthetic-free HPßCD solution being injected. The onset, success, and duration of pulpal anaesthesia were assessed by electrical stimulation ("pulp tester") on inferior molars. Results were analysed using ANOVA (Tukey), log rank, and chi square tests (α=5%). There were no differences among the formulations in onset of anaesthesia (p=0.59) or between the bupivacaine plus epinephrine and bupivacaine plus HPßCD in duration of anaesthesia, but bupivacaine plus epinephrine gave significantly higher values than bupivacaine alone (p=0.007). Bupivacaine plus epinephrine was a better anaesthetic than bupivacaine alone (p=0.02), while Bupi-HPßCD gave intermediate results, and therefore did not differ significantly from the other 2 groups (p=0.18 with bupivacaine alone; and p=0.44 with bupivacaine plus epinephrine). The bupivacaine-HPßCD complex showed similar anaesthetic properties to those of bupivacaine with epinephrine.

Efficacy of liposome-encapsulated 0.5% ropivacaine in maxillary dental anaesthesia.

The aim of this study was to evaluate the effectiveness of liposome-encapsulated ropivacaine (0.5%) in dental anaesthesia. This randomised, double-blind, crossover, four-period treatment study included 40 volunteers who were given 1.8 ml of the following local anaesthetics into the buccal sulcus at the right level of the upper canine: 0.5% ropivacaine; 0.5% ropivacaine with 1:200,000 adrenaline; liposome-encapsulated 0.5% ropivacaine; and 2% lignocaine with 1:100,000 adrenaline. Onset of pulpal anaesthesia; the success of anaesthesia; and the duration of labial, gingival, and pulpal anaesthesia involving the upper right canine and first premolar were evaluated. At the end of each injection, volunteers rated the pain on injection on a visual analogue scale (VAS). Both ropivacaine and adrenaline, and lignocaine with adrenaline, were more successful anaesthetic agents than liposome-encapsulated ropivacaine or plain ropivacaine (p<0.05). There were no significant differences among the anaesthetic preparations in the onset of pulpal anaesthesia. Ropivacaine and adrenaline and lignocaine and adrenaline gave a significantly longer duration of pulpal anaesthesia. VAS showed no significant differences among the groups tested. The results showed that encapsulation of liposome did not improve the anaesthetic efficacy of ropivacaine.

Liposomal delivery system for topical anaesthesia of the palatal mucosa.

An effective topical agent to reduce pain during local anaesthesia of the palate is not yet available. The aim of the present study was to evaluate the efficiency of liposome-encapsulated ropivacaine in different concentrations for topical anaesthesia of the palatal mucosa. In this single-blinded, placebo-controlled, crossover study 40 (20 male) healthy volunteers were randomised to be given: liposome-encapsulated 2% ropivacaine, liposome-encapsulated 1% ropivacaine, a eutectic mixture of 2.5% lidocaine and 2.5% prilocaine (EMLA), and liposomal placebo gel, topically on to the palatal mucosa of the right canine region for 5 min each, at four different sessions. Pain associated with insertion of a 30G needle, and with injection of a local anaesthetic, was rated on a visual analogue scale (VAS). The effect of liposomal ropivacaine 1% and 2% did not differ from that of placebo (p=0.3 and p=0.1, respectively) in reducing pain during insertion of the needle. Lower VAS were obtained with EMLA. In this group VAS were lower in women than men (p=0.007). There was no difference in VAS among groups (p=0.3) as far as injection of the local anaesthetic was concerned. In conclusion, liposomal-encapsulated ropivacaine formulations did not reduce the pain of insertion of a needle into the palatal mucosa. None of the anaesthetic formulations tested, including the positive control (EMLA), were effective in reducing the pain of an injection of local anaesthetic compared with placebo.

Morphological changes in the position of the mandibular foramen in dentate and edentate Brazilian subjects.

This study assessed the mandibular foramen (MF) position variability in dentate and edentate Brazilian mandibles. Eighty dentate and 79 edentate mandibles of unknown sex were measured bilaterally using a digital caliper (0.1-mm precision). Horizontal linear measurements (HM) were done from the MF to the anterior border of the mandibular ramus (MF-A) and from the MF to the posterior border of the mandibular ramus (MF-B). Vertical linear measurements (VM) were done from the MF to the most inferior point of the mandibular notch (MF-C) and from the MF to the inferior border of the mandibular ramus (MF-D). Data were analyzed by two-way ANOVA (alpha = 5%). The HM means and standard deviations (+/-SD) for MF-A were, edentate right (ER): 17.5 (+/-3.2) mm, edentate left (EL): 17.4 (+/-3.4) mm, dentate right (DR): 19.2 (+/-3.6) mm, and dentate left (DL): 18.8 (+/-3.8) mm. The means (+/-SD) for the MF-B measurements were, respectively, ER: 12.8 (+/-2.4) mm, EL: 12.9 (+/-2.3) mm, DR: 14.2 (+/-2.4) mm, and DL: 13.9 (+/-2.6) mm. The VM values for the MF-C measurements were, ER: 23.4 (+/-3.8) mm, EL: 22.9 (+/-3.7) mm, DR: 23.6 (+/-3.1) mm, and DL: 23.1 (+/-3) mm, and for the MF-D measurements, ER: 26.4 (+/-4.2) mm, EL: 26.4 (+/-4) mm, DR 28.3 (+/-3.9) mm, and DL 28 (+/-3.8) mm. Side had no influence (p>0.05) on any edentate or dentate mandible measurement. Dentate mandible measurements showed statistically significant differences compared to the edentate mandibles, except for MF-C. The mandibular foramen position changes with loss of teeth and this variability may be responsible for occasional failure of inferior alveolar nerve block.

Ulceration of gingival mucosa after topical application of EMLA: report of four cases.

This study reports four cases of mucosa ulceration after a 30-minute application of EMLA (0.3 g) as a topical anaesthetic in dentistry. The subjects returned the next day with a white ulceration and desquamation on the application site. EMLA cream should not be applied to the oral mucosa for 30 minutes.

Articaine and lignocaine efficiency in infiltration anaesthesia: a pilot study.

AIM: The purpose of this study was to evaluate the onset of action of pulpal and soft tissue anaesthesia, and pain experience after buccal and palatal infiltrative injections with 4% articaine with 1:100,000 adrenaline, and 2% lignocaine with 1:100,000 adrenaline. METHOD: A double blind cross-over study was conducted with 20 healthy adult subjects who, in two appointments at least two weeks apart, randomly received an infiltration anaesthesia with the solutions in the buccal and palatal regions of the upper right canine. The tooth was tested with a pulp tester before (to establish its baseline response), and after the injection, until return to the base threshold level. The pain experience caused by palatal injection was verified by the visual analogue scale (VAS). Data were analysed using Wilcoxons test (alpha = 0.05). RESULTS: There were no significant statistical differences between the solutions with respect to VAS (p = 0.45), onset of action (p = 0.80) and pulpal (p = 0.08) and soft tissue (p = 0.18) anaesthesia duration, although pulpal anaesthesia may have reached statistical significance if a higher number of volunteers had been used. CONCLUSION: Under the conditions of this study it can be concluded that both anaesthetic solutions showed similar pain experience.

Effects of caffeine and theophylline on the development of dental caries in rats.

The purpose of this study was to evaluate the influence of caffeine and theophylline on the development of dental caries in rats. Six Wistar dams (spf), mutans streptococci free, were obtained, each with six male pups. The dams were infected by Streptococcus sobrinus 6715 and divided into three groups which received during the lactating period: (1) diet 2000; (2) diet 2000 plus caffeine (2 mg/100 g) and (3) diet 2000 plus theophylline (0.57 mg/100 g). After weaning, the pups were infected by S. sobrinus, placed in a König-Höfer programmed feeder machine, and received 17 meals daily at hourly intervals, for five weeks. During this time the pups were fed with the same diet that their dams were. The percentage of S. sobrinus relative to total flora was significantly higher in the theophylline group. The results for slight (Ds) and moderate (Dm) dentine lesions, for smooth-surface and sulcal scores were statistically higher for the theophylline group than the other groups. Salivary assays did not demonstrate significant inorganic alterations in salivary composition. Caffeine and theophylline groups showed the highest ulcer score. It is concluded that caffeine does not affect the cariogenic potential of the diet, however theophylline can increase the development of dental caries, and this effect may be related to organic alterations of salivary composition.

Allergic reaction after rubber dam placement.

In the last few years allergic reactions to natural rubber latex (NRL) have increased in dental practice affecting both the dental team and patients. Some case reports discuss the potential risks of hypersensitivity to NRL products. An adverse patient reaction after dental rubber dam placement is reported. About 1 min after the isolation of the tooth with a rubber dam the patient presented signs and symptoms of hypersensitivity. Oxygen and intravenous hydrocortisone were administered and the patient kept under observation. After 2 h she had stable vital signs and no more allergics symptoms. It is unclear whether components of the NRL dam or the cornstarch powder incorporated with the rubber dam was responsible for the allergic reaction. Dentists must be aware of the health problem and be prepared for an adequate management in dental practice.

Acute toxicity (LD50 and CD50) of lidocaine and prilocaine in combination with adrenaline and felypressin.

The toxicity of the combination of vasoconstrictors to local anaesthetic solutions has been debated since its first use in the beginning of this century. A combination of two vasoconstrictors to a local anaesthetic has been proposed by some researchers. In this study they were evaluated the acute toxicity (lethal dose 50%, convulsion dose 50%) and latency times of loss of righting reflex and convulsion as well as the duration of convulsion) of 2% lidocaine or 3% prilocaine, when administered in combination with adrenaline and felypressin at various concentrations. Lethal dose 50% studies showed that for both anaesthetics the solutions with higher concentrations of adrenaline were more toxic. The opposite was observed in the convulsion dose 50% studies. No alterations were observed in the control groups. All lidocaine solutions increased the latency of loss of righting reflex. The latency of convulsion was increased in some groups, but once the convulsion was achieved there was no difference in its duration. There was no statistical difference among prilocaine groups for any of the variables studied. Based on the experimental model studied, it was concluded that there is no advantage in the association of two vasoconstrictors concerning the toxicity of lidocaine and prilocaine solutions.

Cariogenic [correction of Carcinogenic] potential of a typical cassava flour from the Amazonian region of Brazil.

The purpose of this study was to compare the cariogenic potential of a typical cassava flour (CF) with sucrose and starch, using a severe cariogenic challenge model in rats. Thirty Wistar female pups with their dams (mutans streptococci free) were infected by Streptococcus sobrinus 6715, desalivated when aged 25 days, and placed in a Konig-Hofer programmed feeder at age 26 days. They received 17 meals daily at hourly intervals for 21 days as follows: group (1) powdered plain sucrose and sterile distilled water ad libitum (sdwal); (2) Lf and Sdwal (3) powdered starch and sdwal. Essential nutrition was administered by gavage. Data were analyzed by ANOVA. The percentage of S. Sobrinus related to the total flora and the number of this microorganism were higher in the sucrose and CF groups than starch group. Smooth-surface and [sulcal] caries scores for the groups were: (1) 105.5 [48.0]; (2) 34.1 [39.2]; (3) 10.2 [18.1]. All the groups were statistically significantly different from each other (p < 0.01), although the result for sulcal score for CF was very close to the sucrose group. It is concluded that cassava flour, the main source of carbohydrate for the Amazonian population of Brazil, has moderate cariogenic potential.