The role of the endocannabinoid system in tooth eruption: An ex vivo study.

The aim was to characterise the endocannabinoid system (ECS) in the dental pulp of teeth at different stages of eruption. Pulp of: erupted premolars (EPM), third molars in pre-eruptive (PThM), intraosseous (IThM) and eruptive stages (EThM) (n = 12 each group) were used. Messenger RNA expression of components of the ECS as cannabinoid receptors (CBr1 and CBr2), and anandamide synthetizing (NAPE-PLD) and degradation (FAAH) enzymes were measured by RT-PCR. Data were analysed using Student's t-test for comparisons between two groups and one-way analysis of variance and Tukey's post-test for multiple comparisons (statistical significance: p < 0.05). mRNA expression of CBr2, NAPE-PLD and FAAH was similar in the studied stages, was lower in IThM than in PThM and EThM, and the lowest in EThM (p < 0.01); of note, CBr2 mRNA expression was not detected in EThM. CBr1 mRNA did not differ significantly between IThM and PThM but was lower in EThM (p < 0.01). The absence of CBr2 and presence of CBr1 in EThM suggest the involvement of the ECS via CBr1 as a mediator of tooth and bone tissue homeostasis during tooth eruption.

Fotobiomodulación con láser de baja intensidad en el tratamiento integral ortodóntico: reporte de un caso / Photobiomodulation with low intensity laser in comprehensive orthodontic treatment: report of a case

El apiñamiento dental es una maloclusión frecuen-te y junto con los requerimientos de estética dental son una causa habitual de la solicitud de tratamien-to ortodóncico. El tiempo que demanda y las moles-tias que pudiera ocasionar el tratamiento produce inquietud en los pacientes y un esfuerzo de los or-todoncistas para optimizar el tiempo y prevenir los efectos adversos. Los tratamientos odontológicos multidisciplinarios permiten una mejor respuesta estética, funcional y de estabilidad post tratamiento. El tiempo de alineación dentaria y finalización, en los pacientes tratados con láser de baja intensidad po-dría mejorar tanto los índices gingivales como la res-puesta al dolor. Adicionalmente, las corticales óseas de los pacientes con ortodoncia tratados con láser, podrían verse menos afectadas en comparación con las de los pacientes no tratados. Se presenta un caso de fotobioestimulación con láser de baja intensidad aplicado en un paciente en fase de alineación, que forma parte de un estudio prospectivo aleatorizado que se desarrolla en la FOUBA y fue aprobado por el comité de Ética de la institución. El paciente aceptó y firmó el consentimiento informado. Finalizada la etapa de alineación, se evaluó la efectividad de la te-rapia con láser de baja intensidad actualmente de-nominada fotobiomodulación en incisivos superiores en la fase de alineación para acelerar el movimiento dentario, la respuesta gingival, el dolor, el estado de la cortical alveolar vestibular y la estética del perfil (AU)

Dental crowding, which is a frequent malocclusion, and dental aesthetic requirements are a common cause for requesting orthodontic treatment. The time that the treatment requires and the inconvenience that it could cause worries the patient and makes orthodontists strive to optimize time and prevent adverse effects. Multidisciplinary treatments would allow a better aesthetic, functional and post-treatment stability response. The dental alignment and completion time in patients treated with low-intensity laser could improve both gingival indices and response to pain. Additionally, the bone cortical of orthodontic patients treated with laser could be less affected compared to those of untreated patients. A case of low-intensity laser photobiostimulation applied to a patient in the alignment phase is presented, which is part of a prospective randomized study carried out at FOUBA and was approved by the institution's Ethics Committee. The patient accepted and signed the informed consent. After the alignment phase, the effectiveness of low-level laser therapy actually called photobiomodulation in upper incisors in the alignment phase is evaluated to accelerate tooth movement; the gingival response; the pain; the vestibular alveolar cortical and the aesthetics of the profile (AU)

Changes in PGE2 signaling after submandibulectomy alter post-tooth extraction socket healing.

Saliva is very important to oral health, and a salivary deficit has been shown to bring serious problems to oral health. There is scant information about the mechanisms through which salivary glands participate in post-tooth extraction socket healing. Therefore, the aim of the present study was to investigate the effect of submandibulectomy (SMx), consisting of the ablation of submandibular and sublingual glands (SMG and SLG, respectively), on PGE2 signaling and other bone regulatory molecules, such as OPG and RANKL, involved in tooth extraction socket healing. Male Wistar rats, 70 g body weight, were assigned to an experimental (subjected to SMx) or a control group (sham operated). One week later, the animals in both groups underwent bilateral extraction of the first mandibular molars. The effect of SMx on different stages of socket healing after tooth extraction (7, 14, and 30 days) was studied by evaluating some parameters of inflammation, including PGE2 and its receptors, and of bone metabolism, as well as by performing bone biomechanical studies. SMx increased TNFα and PGE2 content as well as cyclooxygenase-II (COX-II) expression in tooth socket tissue at almost all the studied time points. SMx also had an effect on mRNA expression of PGE2 receptors at the different time points, but did not significantly alter osteoprotegerin (OPG) and RANKL mRNA expression at any of the studied time points. In addition, an increase in bone mass density was observed in SMx rats compared with matched controls, and the structural and mechanical bone properties of the mandibular socket bone were also affected by SMx. Our results suggest that the SMG/SLG complex regulates cellular activation and differentiation by modulating the production of molecules intervening in tooth extraction socket repair, including the PGE2 signaling system, which would therefore account for the higher density and resistance of the newly formed bone in SMx rat.

Ethanol consumption enhances periodontal inflammatory markers in rats.

OBJECTIVE: The aim of this study was to assess the short term effect of ethanol administration on periodontal disease in rats. DESIGN: Rats received either ethanol 2g/kg or water by gastric gavage twice a day. On the fifth day ligatures were tied around the molars of half of the rats to induce periodontitis. After 7days gingival tissue was removed and assayed for inflammatory markers. Finally, hemi-mandibles were extracted to evaluate bone loss by histomorphometrical techniques. RESULTS: The experimental periodontitis increased significantly the mRNA expression (p<0.001) and activity (p<0.001) of inducible nitric oxide synthase (iNOS) in the gingival tissue, whilst short time ethanol administration increased iNOS activity (p<0.05) and produced an additive effect on iNOS mRNA expression augmented by periodontitis (p<0.01). The short time ethanol administration also potentiated the periodontitis stimulatory effect on the mRNA expression of interleukin (IL)-1ß (p<0.01 and p<0.001, in semi-quantitative and real time PCR, respectively) and on the height of periodontal ligament (p<0.05). However, the ligature-induced periodontitis, but not ethanol administration, increased the prostaglandin E(2) content (p<0.05) and, diminished the alveolar bone volume (p<0.05), as compared to sham rats. CONCLUSION: The present results suggest that ethanol consumption could represent a risk indicator for periodontal disease since augments the expression of inflammatory markers, in healthy rats, and increases them, at short term, during the illness. However, scale longitudinal investigation and more case-control studies are needed to confirm this statement.

Acute effect of manganese on hypothalamic luteinizing hormone releasing hormone secretion in adult male rats: involvement of specific neurotransmitter systems.

Manganese chloride (MnCl2) is capable of stimulating luteinizing hormone releasing hormone (LHRH) secretion in adult male Sprague-Dawley rats through the activation of the hypothalamic nitric oxide/cyclic guanosine monophosphate (cGMP)/protein kinase G pathway. The present study aimed to determine the involvement of specific neurotransmitters involved in this action. Our results indicate that dopamine, but not glutamic acid and prostaglandins, mediates the MnCl2 stimulated secretion of LHRH from medial basal hypothalami in vitro, as well as increases the activity of nitric oxide synthase. Furthermore, a biphasic response was observed in that gamma aminobutyric acid (GABA) release was also increased, which acts to attenuate the MnCl2 action to stimulate LHRH secretion. Although it is clear that manganese (Mn+2) can acutely induce LHRH secretion in adult males, we suggest that the additional action of MnCl2 to release GABA, a LHRH inhibitor, may ultimately contribute to suppressed reproductive function observed in adult animals following exposure to high chromic levels of Mn+2.