Amaury Pozos-Guillén

Hemocompatibility assessment of poly(2-dimethylamino ethylmethacrylate) (PDMAEMA)-based polymers

Poly(2-dimethylamino-ethylmethacrylate) (PDMAEMA), a cationic polymer, has been widely reported as a nonviral carrier. Despite the fact that the cytotoxicity of this polymer has been extensively studied, there is a lack of information about its blood compatibility. Hence, this work evaluates the hemocompatibility of free-form PDMAEMA homopolymers differing in molecular weight (Mw) with or without a poly(ethylene glycol) (PEG) sequence in the form of a palm tree-like structure. Poly(ethylenimine) (PEI) was used as a reference in order to compare its hemoreactivity. Hemagglutination, hemolysis, platelet number, blood coagulation, and the complement systems were assessed in normal human whole blood according to the ISO 10993-4. Results showed that Mw, concentration, and incubation time strongly affected the hemocompatibility of the polymers evaluated. Our in vitro observations highlight that PDMAEMA homopolymers interacted strongly with the surface of the red blood cells but not with the inner structure of the membrane, while PEI behaved in the opposite way. No clear correlation has been evidenced between PDMAEMA-induced hemagglutination, PEI-induced hemagglutination, and hemolysis. Interestingly, if these polyelectrolytes strongly affect the platelets and blood coagulation cascades in a dose dependent way, none of them significantly affects the complement system. Our work reveals new knowledge on the toxicology of 2 families of polycations largely explored for gene delivery and on their mechanisms of cellular and humoral interactions.

Use of Therapeutic Laser After Surgical Removal of Impacted Lower Third Molars

PURPOSE To evaluate the effectiveness of a therapeutic laser in the control of postoperative pain, swelling, and trismus associated with the surgical removal of impacted third molars. PATIENTS AND METHODS A double-blind, randomized, controlled clinical trial was conducted in 2 groups of 15 patients each undergoing surgical removal of impacted lower third molars under local anesthesia. The experimental group received 4 J/cm(2) of energy density intraorally and extraorally, with a laser with a diode wavelength of 810 nm and output power of 100 mW in a continuous wave. The control group received only standard management. The degree of postoperative pain, swelling, and trismus was registered for both groups. RESULTS The experimental group exhibited a lower intensity of postoperative pain, swelling, and trismus than the control group, without significant statistical differences. Patients of both groups required rescue medication; however, the time lapse between the end of the surgery and the administration of the medication was shorter for the control group. CONCLUSION The use of therapeutic laser in the postoperative management of patients having surgical removal of impacted third molars, using the protocol of this study, decreases postoperative pain, swelling, and trismus, without statistically significant differences.

Bebidas embotelladas como fuentes adicionales de exposición a flúor

ResumenObjetivo . Evaluar y notificar la concentracion de fluoruroen bebidas embotelladas que se consumen en la ciudad deSan Luis Potosi, S.L.P., Mexico y su implicacion como factorde riesgo a fluorosis dental. Material y metodos . Seestudio el contenido de algunos productos de las dos com-panias refresqueras mas importantes de Mexico y de otrasdos locales. Las muestras se recolectaron de 10 lotesdiferentes en el caso de los refrescos y de cinco lotes en elde los jugos, con tres muestras por lote, durante tres me-ses. La determinacion de concentracion de fluoruro serealizo mediante el metodo del electrodo de ion selectivo. Resultados . La concentracion de fluor de muestras dediferentes plantas de companias nacionales presentarondiferencias estadisticas significativas entre grupos ( p < 0.05).La comparacion de resultados entre companias nacionalesy locales tambien mostro diferencia estadistica significativa( p < 0.05). Los diferentes jugos presentaron concentracionesde fluor elevadas.

Biofilm formation by oral clinical isolates of Candida species.

We have conducted a longitudinal study to quantify biofilms in oral clinical isolates of Candida species (spp.) from adults with local and systemic predisposing factors for candidiasis. A total of 69 yeast isolates from 63 Mexican patients were evaluated. These isolates (39 C. albicans, 15 C. tropicalis, 7 C. glabrata, 4 C. krusei, 1 C. lusitaniae, 1 C. kefyr, 1 C. guilliermondii and 1 C. pulcherrima) were obtained from two clinical sites: 62.3% (n=43) from the oral mucosa of totally and partially edentulous patients, and 37.7% (n=26) from the oral mucosa of diabetics. In addition, Candida ATCC strains were used as controls for each experiment. The kinetics of biofilm formation were measured by 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide [XTT] reduction; each isolate was tested at 6, 12 and 24h. Biofilm formation is dependent on the Candida spp. and its clinical origin. On average, the oral isolates of C. glabrata are strong biofilm producers, whereas C. albicans and C. tropicalis are moderate producers. The most common species in our population was C. albicans. While the kinetics of C. albicans biofilm formation varies between oral isolates, it generally maintains steady growth from 2 to 48h, when it reaches its maximum growth.

Analgesic efficacy and safety of single-dose tramadol and non-steroidal anti-inflammatory drugs in operations on the third molars: a systematic review and meta-analysis

The aim of this systematic review and meta-analysis was to evaluate published randomised, double-blind, clinical trials to compare the analgesic efficacy and safety of tramadol with that of non-steroidal anti-inflammatory drugs (NSAID) in operations on the third molars. We identified eligible reports from searches of PubMed, MedLine, the Cochrane Library, Oxford Pain Relief database, Imbiomed, and Google Scholar. The full text of studies that met our minimum requirements were evaluated using inclusion and exclusion criteria with the Oxford Quality Scale. Those with a Score ≥ 3 in this scale were included and their data were extracted and analysed. Absolute increase in risk, the number needed to harm, odds ratio and 95% CI were calculated using Risk Reduction Calculator software. Each meta-analysis was made with the help of the Mantel-Haenszel random effects model, estimates of risk (odds ratio (OR)) and 95% CI were calculated using the Review Manager 5.2. from the Cochrane Library. A significant risk was assumed when the lower limit of the 95%CI was greater than 1. Probabilities of less than 0.05 were accepted as significant. The results showed that tramadol had less analgesic efficacy and an increased risk of adverse effects compared with NSAID. In conclusion, a single dose of tramadol was not as effective or as safe as NSAID for the relief of pain after operations on the third molars.

Expression of substance P, calcitonin gene-related peptide, β-endorphin and methionine-enkephalin in human dental pulp tissue after orthodontic intrusion: A pilot study

OBJECTIVE To determine the levels of two sensory neuropeptides (substance P [SP] and calcitonin gene-related peptide [CGRP]) and two endogenous opioids (methionine-enkephalin [Met-Enk] and β-endorphin [β-End]) in dental pulp tissue samples subjected to controlled orthodontic intrusive forces. MATERIALS AND METHODS Sixteen healthy premolars were selected from eight patients who were undergoing extraction for orthodontic purposes. Eight were randomly used as controls, and the other eight were assigned to an experimental group (controlled orthodontic intrusive forces applied for 24 hours). After this period, teeth were extracted, and pulp samples were obtained. All samples were processed to quantify the expression levels of SP, CGRP, Met-Enk, and β-End using commercial radioimmunoassay kits. RESULTS All samples exhibited basal levels of both neuropeptides and endogenous opioids. After 24 hours of the intrusive stimulus, all patients reported a tolerable discomfort localized at the involved premolar. Only SP was significantly increased (P<.05). For the other molecules, no statistically significant differences were observed (P>.05); however, they expressed important increasing trends. CONCLUSIONS The expression levels of SP and CGRP in dental pulp samples from the experimental group support the positive correlation between the symptomatic clinical scenario and increased expression levels of neuropeptides, clarifying the role of neurogenic inflammation in early injury response.

Reattachment of anterior teeth fragments using a modified Simonsen's technique after dental trauma: report of a case.

This is a case report of a 9-year-old boy with complicated crown fractures of two traumatized teeth: left maxillary central and lateral incisors. The central incisor presented a small pulpal exposure of approximately 1 mm and the lateral incisor had an ulcerated and exposed pulp. Endodontic management included direct pulp capping, partial pulpotomy, and restorative management including reattachment of the teeth fragments using a modified Simonsens technique. The reattached fragments were assessed clinically and radiographically at 12 months. The teeth remained vital, there were no color changes, and the restorations had an acceptable appearance.

Eugenol Toxicity in Human Dental Pulp Fibroblasts of Primary Teeth

OBJECTIVE The aim of the study was to determine the eugenol concentrations at which toxicity occurs in human dental pulp fibroblasts of primary teeth. STUDY DESIGN Samples of primary dental pulp tissue were taken. Tissue samples were seeded by means of explant technique and used in the 4(th)-5th pass. Single Cell Gel Electrophoresis (Comet), phenazine MeThoSulfate (MTS), LIVE/DEAD Cell Viability/Toxicity and trypan blue assays for evaluation of the cytotoxicity of increasing concentrations of eugenol (0.06 to 810 μM) were performed. RESULTS The results of toxicity tests showed toxic effects on dental pulp fibroblasts, even at very low concentrations of eugenol (0.06 μM). Very low concentrations of eugenol produce high toxicity in human dental pulp fibroblasts. CONCLUSIONS All of the concentrations of eugenol that we evaluated produced high toxicity in human dental pulp fibroblasts of primary teeth.

Efficacy of mepivacaine–tramadol combination on the success of inferior alveolar nerve blocks in patients with symptomatic irreversible pulpitis: a randomized clinical trial

AIM To compare the success of an inferior alveolar nerve block (IANB) after injecting a combination of mepivacaine and tramadol or mepivacaine alone in patients with symptomatic irreversible pulpitis (SIP) in mandibular permanent molars. METHODOLOGY This study was a double-blind, randomized, controlled clinical trial. Two study groups were selected, each consisting of 28 patients who exhibited SIP on the first or second mandibular molars. All included patients presented with moderate-to-severe preoperative pain according to the modified Heft-Parker visual analogue scale (VAS). Patients were anaesthetized using the IANB technique employing identical cartridges that contained either 1.3 mL of 2% mepivacaine with epinephrine 1 : 100 000 plus 0.5 mL of tramadol 50 mg mL(-1) (experimental group) or 1.8 mL of 2% mepivacaine with epinephrine 1 : 100 000 (control group). After 15 min, anaesthesia was evaluated by a progressive four-test examination, that is numbness of the lip, positive or negative cold test, asymptomatic management of dental hard tissues and access to dental pulp. Success of the IANB was defined as the absence of pain during any of these evaluations. The data were analysed with a chi-square, Fishers or Mann-Whitney U test. RESULTS A total of 74 patients were initially assessed, with 56 patients eventually included and 18 excluded. No significant differences in age (P = 0.384) or gender (P = 1) were found between the two groups. The success rates of anaesthesia with the IANB for the experimental and control groups were 57.1 and 46.4%, respectively. The success rate of anaesthesia in the experimental group was not significantly different (P ˃ 0.05) from that of the control group. The duration of the anaesthetic effect was significantly longer for the experimental group (P = 0.026). CONCLUSION The combination of mepivacaine-tramadol achieved similar success rates for IANB when compared to mepivacaine 2% epinephrine 1 : 100 000. There was no significant difference in the anaesthetic efficacy between the control and experimental solutions, and none of the solutions tested were completely successful.

Effect of 4-Allyl-1-hydroxy-2-methoxybenzene (Eugenol) on Inflammatory and Apoptosis Processes in Dental Pulp Fibroblasts

Eugenol (mixed with zinc oxide powder) is widely used as direct capping material during pulp therapy in primary teeth. The aim of the present study was to evaluate the effect of eugenol on diverse genes involved in inflammatory and cell apoptosis processes. The regulatory effect of eugenol on the expression of inflammation and apoptotic genes was evaluated in dental pulp fibroblasts from extracted third molars, cultured under concentration of eugenol of 13 μM. Eugenol allowed the expression of inflammatory and apoptotic genes when compared with positive and negative controls. Eugenol is a proinflammatory agent when it is in direct contact with healthy tissues and behaves as an anti-inflammatory agent in tissues undergoing inflammatory/apoptotic processes, as in cases of pulp inflammation in primary teeth. These findings are relevant for dentistry, when considering the application of safer pulp treatments to grossly carious childrens teeth.