Francisco Carlos Groppo

Use of Phytotherapy in Dentistry

Over the past decade, interest in drugs derived from medicinal plants has markedly increased. This study was aimed at a literature review focusing on studies investigating herbal drugs and other natural products, as well as their therapeutic application, side effects and possible drug interactions. Few studies were found to support their rational use in dentistry. Since there is an increasing use of phytotherapeutic agents in dentistry, further studies are needed to evaluate their safety and effectiveness for clinical use. Copyright

Micro and nanosystems for delivering local anesthetics

Introduction: One of the most common strategies for pain control during and after surgical procedures is the use of local anesthetics. Prolonged analgesia can be safely achieved with drug delivery systems suitably chosen for each local anesthetic agent. Areas covered: This review considers drug delivery formulations of local anesthetics designed to prolong the anesthetic effect and decrease toxicity. The topics comprise the main drug delivery carrier systems (liposomes, biopolymers, and cyclodextrins) for infiltrative administration of local anesthetics. A chronological review of the literature is presented, including details of formulations as well as the advantages and pitfalls of each carrier system. The review also highlights pharmacokinetic data on such formulations, and gives an overview of the clinical studies published so far concerning pain control in medicine and dentistry. Expert opinion: The design of novel drug delivery systems for local anesthetics must focus on how to achieve higher uploads of the anesthetic into the carrier, and how to sustain its release. This comprehensive review should be useful to provide the reader with the current state-of-art regarding drug delivery formulations for local anesthetics and their possible clinical applications.

A survey of local anaesthetic use among general dental practitioners in the UK attending postgraduate courses on pain control

Objective The aim of this study was to identify which local anaesthetic solutions were used by general dental practitioners in the United Kingdom and to determine selection criteria. In addition, differences in anaesthetic choice between recent graduates (≤5 years) and more experienced practitioners were investigated.Material and methods Five hundred and six general dental practitioners attending postgraduate courses on pain control in dentistry completed a questionnaire. Participants were asked to indicate year and place of qualification, anaesthetic solutions available in their surgeries and criteria used in the choice of anaesthetic. In addition, the respondents were asked to indicate choice of local anaesthetic in a number of common medical conditions. Questionnaires were distributed and collected immediately prior to the start of the course presentation and participants were not asked to indicate whether the selection decisions were teaching, experience or evidence based. Data were analysed by using the Chi-square test.Results Lidocaine with epinephrine was the most widely available solution among this group of practitioners (94%), the second most common solution was prilocaine with felypressin (74%). The majority of practitioners had two or more solutions available. Practitioners who qualified within the last five years (14%) were more likely to have articaine available, the most recently introduced local anaesthetic into the UK (p = 0.04, one degree of freedom). Common medical conditions lead to a modification in anaesthetic selection: the use of prilocaine/felypressin increases in the majority of circumstances, although it is avoided in pregnant females by recent graduates.Conclusions Lidocaine/epinephrine continues to be the most common anaesthetic solution used by this group of UK general practitioners. The primary criterion for selection of an anaesthetic agent was perceived efficacy. Prilocaine/felypressin is commonly selected as an alternative solution in the presence of common medical conditions.

Inhibition of matrix metalloproteinase-9 activity by doxycycline ameliorates RANK ligand-induced osteoclast differentiation in vitro and in vivo.

Tetracycline antibiotics, including doxycycli\e (DOX), have been used to treat bone resorptive diseases, partially because of their activity to suppress osteoclastogenesis induced by receptor activator of nuclear factor kappa B ligand (RANKL). However, their precise inhibitory mechanism remains unclear. Therefore, the present study examined the effect of Dox on osteoclastogenesis signaling induced by RANKL, both in vitro and in vivo. Although Dox inhibited RANKL-induced osteoclastogenesis and down-modulated the mRNA expression of functional osteoclast markers, including tartrate-resistant acid phosphatase (TRAP) and cathepsin K, Dox neither affected RANKL-induced MAPKs phosphorylation nor NFATc1 gene expression in RAW264.7 murine monocytic cells. Gelatin zymography and Western blot analyses showed that Dox down-regulated the enzyme activity of RANKL-induced MMP-9, but without affecting its protein expression. Furthermore, MMP-9 enzyme inhibitor also attenuated both RANKL-induced osteoclastogenesis and up-regulation of TRAP and cathepsin K mRNA expression, indicating that MMP-9 enzyme action is engaged in the promotion of RANKL-induced osteoclastogenesis. Finally, Dox treatment abrogated RANKL-induced osteoclastogenesis and TRAP activity in mouse calvaria along with the suppression of MMP9 enzyme activity, again without affecting the expression of MMP9 protein. These findings suggested that Dox inhibits RANKL-induced osteoclastogenesis by its inhibitory effect on MMP-9 enzyme activity independent of the MAPK-NFATc1 signaling cascade.

Liposome-encapsulated ropivacaine for topical anesthesia of human oral mucosa.

BACKGROUND:The elimination of pain caused by needle insertion for local anesthesia would be a significant advance in dentistry. METHODS:In this blinded cross-over study we evaluated the efficacy of liposome-encapsulated ropivacaine for topical anesthesia. Thirty healthy volunteers received 60 mg topical anesthetics: Liposome-encapsulated 1% ropivacaine, 1% plain ropivacaine, 2.5% lidocaine and 2.5% prilocaine mixture (EMLA), and 20% benzocaine gel, in the buccal fold of the upper-right canine for 2 min in different sessions. After insertion of 30-G needles, pain was rated on a visual analog scale (VAS). A pinprick test was used to measure the duration of topical anesthesia. The pulpar response was assessed by an electric pulp tester. RESULTS:VAS median and interquartile range (in cm) were 0.8 (0.4–1.5), 1.6 (0.8–2.6), 1.1 (0.3–2.7), 2.2 (0.9–2.9) for liposome-encapsulated ropivacaine, ropivacaine, EMLA, and benzocaine groups, respectively. The liposome-encapsulated ropivacaine group showed lower VAS mean values when compared with the benzocaine group (P = 0.0205). The median values and interquartile range for the duration of soft tissue anesthesia were 11 (7–14), 6.5 (4–11), 14 (11–16), and 7 (6–9) min for liposome-encapsulated ropivacaine, ropivacaine, EMLA, and benzocaine groups, respectively. EMLA and liposome-encapsulated ropivacaine were just as efficient for reducing pain, and showed longer soft tissue anesthesia when compared to the other local anesthetics (P = 0.0001). CONCLUSION:Liposomal-encapsulated 1% ropivacaine gel was equivalent to EMLA® for reducing pain during needle insertion and for the duration of soft tissue anesthesia. None of the topical anesthetics was effective for inducing pulpal anesthesia.

The effects of nicotine and cotinine on Porphyromonas gingivalis colonisation of epithelial cells.

Smoking is a risk factor for development of periodontitis. Porphyromonas gingivalis is an important colonizer of the subgingival crevice and is a major pathogenic agent in the initiation and progression of severe forms of periodontal disease. However, the effect of major cigarettes derivatives on P. gingivalis is poorly understood. The purpose of this study was to determine the influence of nicotine and cotinine on bacterial colonisation to epithelial cells. KB cells monolayers and P. gingivalis ATCC 33277 were exposed to 0.1, 10 and 100 microg/mL of nicotine and cotinine concentrations. The epithelial cells were incubated for 24 h while P. gingivalis was exposed to these substances until reach early logarithmic phase. After the incubation period, P. gingivalis ability to colonize KB cells was assayed. The number of cell-associated/invasive bacteria was assessed by counting the colony-forming units. 100 microg/mL cotinine significantly increased P. gingivalis association and invasion of epithelial cells, when the bacteria was exposed to this substance (p<0.05; ANOVA-Tukey test). No other condition or drug altered the bacteria colonisation ability (p>0.05). These data indicated that cotinine may interfere with P. gingivalis ability to associate and invade the epithelial cells. Further studies are needed to investigate whether oral cells might be more susceptible to be colonized by P. gingivalis in smokers.

Statins and Antimicrobial Effects: Simvastatin as a Potential Drug against Staphylococcus aureus Biofilm

Statins are important lipid-lowering agents with other pleiotropic effects. Several studies have explored a possible protective effect of statins to reduce the morbidity and mortality of many infectious diseases. Staphylococcus aureus is one of the main pathogens implicated in nosocomial infections; its ability to form biofilms makes treatment difficult. The present study observed the MIC of atorvastatin, pravastatin and simvastatin against S. aureus, Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecalis. Simvastatin was the only agent with activity against clinical isolates and reference strains of methicilin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). Thus, the effects of simvastatin on the growth, viability and biofilm formation of S. aureus were tested. In addition, a possible synergistic effect between simvastatin and vancomycin was evaluated. Simvastatin’s MIC was 15.65 µg/mL for S. aureus 29213 and 31.25 µg/mL for the other strains of S. aureus. The effect of simvastatin was bactericidal at 4xMIC and bacteriostatic at the MIC concentration. No synergistic effect was found between simvastatin and vancomycin. However, the results obtained against S. aureus biofilms showed that, in addition to inhibiting adhesion and biofilm formation at concentrations from 1/16xMIC to 4xMIC, simvastatin was also able to act against mature biofilms, reducing cell viability and extra-polysaccharide production. In conclusion, simvastatin showed pronounced antimicrobial activity against S. aureus biofilms, reducing their formation and viability.

Influence of gender and menstrual cycle on volatile sulphur compounds production

The menstrual cycle has been pointed out as a factor influencing halitosis. However, this relationship has not yet been clarified. The aim of this study was to evaluate the influence of gender and the menstrual cycle on the production of volatile sulphur compounds (VSC) in women (n=14) across the menstrual cycle, and in men (n=17). Volunteers in good oral and general health were submitted to the evaluation of VSC, salivary flow, cortisol and anaerobic bacteria counts in saliva. Data were compared among groups by Analysis of Variance (alpha=5%). VSC was higher in the menstrual and premenstrual phases when compared with men and the follicular phase (p<0.05). Salivary flow was lower in the menstrual and premenstrual phases when compared with men and the follicular phase (p<0.05). Salivary cortisol was higher in the menstrual phase in comparison with men and the premenstrual and follicular phases (p<0.05). Total salivary protein was higher in men when compared to women (p<0.05) with no differences among menstrual phases (p>0.05). Levels of anaerobic micro-organisms, however, were not different among groups (p>0.05). In conclusion, the production of VSC is influenced by menstrual cycle and protein concentration and salivary flow might be involved in this process.

Anesthetic Efficacy of Articaine and Lidocaine for Incisive/Mental Nerve Block

INTRODUCTION The incisive/mental nerve block (IMNB) could be an alternative to the inferior alveolar nerve block in the mandibular anterior teeth. The effectiveness of articaine has not been tested in IMNB. METHODS This prospective randomized double-blind crossover study compared the anesthetic efficacy of 0.6 mL 4% articaine and 2% lidocaine, both with 1:100.000 epinephrine administered as IMNB to 40 volunteers in two sessions. Pulpal anesthesia of lateral incisor through premolars was tested with an electric pulp tester. The injection and postoperative pain were evaluated by using visual analog scales. The onset (time from the end of injection to the absence of pulpal response) and duration of pulpal anesthesia (time recorded before two positive responses to the pulp tester) and the anesthesia success (two consecutive readings of 80 without response and onset<or=10 minutes) were measured. RESULTS Articaine provided a higher success rate (p<0.001) of anesthesia than lidocaine for the lateral incisor (32.5%), the canine (55%), and the first (72.5%) and second (80%) premolars and a faster onset (p<0.05) for canine and increased duration (p<0.05) of anesthesia for premolars. The median duration of premolars anesthesia was 10 and 20 minutes, respectively, with lidocaine and articaine. There were no differences in pain scores between the solutions (p>0.05). CONCLUSIONS Articaine promoted higher anesthesia success and longer duration of anesthesia than lidocaine for most of the teeth after IMNB although anesthesia success could be considered clinically appropriated only for premolars. The volume of local anesthetic used in the present study may not be appropriate for procedures lasting longer than 10 minutes.

Anesthetic Efficacy of Bupivacaine Solutions in Inferior Alveolar Nerve Block

The purpose of this study was to compare the anesthetic efficacy of 2 bupivacaine solutions. Twenty-two volunteers randomly received in a crossover, double-blinded manner 2 inferior alveolar nerve blocks with 1.8 mL of racemic bupivacaine and a mixture of 75% levobupivacaine and 25% dextrobupivacaine, both 0.5% and with 1 : 200,000 epinephrine. Before and after the injection, the first mandibular premolar was evaluated every 2 minutes until no response to the maximal output (80 reading) of the pulp tester and then again every 20 minutes. Data were analyzed using the Wilcoxon paired test and the paired t test. No differences were found between the solutions for onset and duration of pulpal anesthesia and duration of soft tissue anesthesia (P > .05). It was concluded that the solutions have similar anesthetic efficacy.