Pre-odontoblast proliferation induced by near-infrared laser stimulation

OBJECTIVE: Laser therapy is known to stimulate cell proliferation and differentiation, an effect called "biostimulation". Although many clinical applications of laser therapy take advantage from such positive effect, the underlying molecular mechanisms are not fully understood. The aim of this work was to investigate the effect of near-infrared laser stimulation on rat pre-odontoblast cells (MDPC-23 cells) and the molecular mechanism/s involved. MATERIALS AND METHODS: MDPC-23 cells were stimulated with a near-infrared (980 nm) laser source with different energy settings (1-50 J, corresponding to 0.65-32.47 J/cm2) and cell proliferation was evaluated by manual count. ERK 1/2 pathway activation was evaluated by Western blot analysis. RESULTS: 1-10 J stimulation (corresponding to 0.65-6.5 J/cm2) significantly increase MDPC-23 cell proliferation and such effect seems to be mediated by ERK 1/2 signalling pathway activation, showing a key role of ERK 1/2 pathway in mediating the proliferative response induced by laser stimulation. CONCLUSIONS: Near infrared laser stimulation with low energies (1-10 J) is able to increase cell proliferation through ERK 1/2 signalling pathway activation. At the same time, higher energy stimulation (25-50 J) induces an initial toxic effect, probably activating pro-apoptotic signalling molecules, downstream ERK 1/2 kinase. Such results foster the application of this therapeutic approach in different clinical settings in which a regenerative tissue response is needed

Epiregulin-loaded PLGA nanoparticles increase human keratinocytes proliferation: preliminary data

OBJECTIVE:Epiregulin is a member of the epidermal growth factor (EGF) family produced by keratinocytes: the aim of this study was to investigate the ability of biocompatible nanoparticles loaded with such growth factor to increase human keratinocytes proliferation. MATERIALS AND METHODS:Different PLGA (Poly-d,l-lactide-co-glycolide)-nanoparticles (NPs) formulations have been characterized in size and zeta potential by dynamic light scattering (DLS) analysis. The ability of the different PLGA-NPs formulations to adhere onto dental surfaces has been tested, and epiregulin-enriched PLGA-NPs has been produced. Epiregulin release from NPs has been tested by enzyme-linked immunosorbent (ELISA) assay and the proliferative effects of epiregulin-NPs on human keratinocytes have been evaluated. RESULTS:DLS analysis revealed a different size distribution depending on the PLA/PGA (poly lactic acid/poly glycolic acid) ratio used. 50:50 PLGA-NPs exhibited the smaller size and the best dental adhesive ability. Moreover, such epiregulin-loaded NPs was able to increase cell proliferation. CONCLUSIONS:Direct dental pocket drug delivery implies the NPs solution loading onto the dental surface at the cement-enamel junction level: 50:50 PLGA-NPs, with their small size and excellent adhesive ability, represent an interesting tool to deliver epiregulin directly where there is the need for epithelial proliferation. These results describe a possible strategy for periodontal pocket delivery of Epiregulin-loaded PLGA-NPs and might provide a new approach for the treatment of gingival recession, where gingival epithelium proliferation is needed

Oral hygiene and ONJ: a review of the literature.

The importance of oral hygiene to minimise their risk of ONJ has often been emphasized in the literature.Some patients may require a change in behaviour in terms of brushing, interdental cleaning and other oral hygiene techniques, as well as other lifestyle behaviours such as diet and tobacco use. There may also be a benefit in prescribing high fluoride toothpaste for those patients with increased caries risk.Therefore, dental hygienists and dental practitioners should give personalised preventive advice to help the patient optimise their oral health, emphasising the importance of having a healthy diet and reducing sugary snacks and drinks; maintaining excellent oral hygiene; and using fluoride toothpaste and fluoride mouthwash.The aim of the present communication was to review the literature about the protocols, methods and advises about a correct home and professional oral hygiene in patients at risk for development of ONJ and in patients affected by ONJ

Bilateral ONJ in a patient affected by metastatic prostate adenocarcinoma.

We present the diagnosis and management of a case of bilateral ONJ of the mandible in a patient that had been taking zoledronic acid treatment for 7 years following a diagnosis of metastatic prostate adenocarcinoma. The patient was referred to our Division by his dental practitioner, that had performed the extraction of the left lower first molar six months before. In the first months after the extraction the patient did not reported any symptom and he started to use a mandibular removable prosthesis. About 5 months following the extraction, the patient started to complain of pain in correspondence of the left body region. He had performed a panoramic radiograph and a CT scan showing a possible initial stage of mandibular ONJ bilaterally, with a predominance in the left mandibular body in the post-extraction socket.Therefore, a curettage of the left mandibular body was decided. Postoperative course was uneventful.Twelve months later, the patient complained of pain in the right mandibular region and in correspondence of the residual right lower third molar. A panoramic radiograph confirmed the extension of mandibular right ONJ. A curettage of the right mandibular body, together with the removal of the right lower third molar, was performed, with a following uneventful postoperative course. Two years later, the patient complained of pain in the left mandibular region in correspondence of the residual left lower second premolar. A panoramic radiograph confirmed the extension of mandibular left ONJ with involvement of the root of the aforementioned premolar. A curettage of the right mandibular body, together with the removal of the left lower second premolar, was performed, with a following uneventful postoperative course. Three years later, a complete healing was obtained

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca