Novel non-resorbable polymeric-nanostructured scaffolds for guided bone regeneration.

OBJECTIVE: The aim of this study was to evaluate the bone-regeneration efficiency of novel polymeric nanostructured membranes and the effect of zinc, calcium, titanium, and bone morpho-protein loading on membranes, through an in vivo rabbit model. MATERIAL AND METHODS: Nanostructured membranes of methylmethacrylate were loaded with zinc, calcium, TiO2 nanoparticles, and bone-morphogenetic protein (BMP). These membranes covered the bone defects prepared on the skulls of six rabbits. Animals were sacrificed 6 weeks after surgery. Micro computed tomography was used to evaluate bone architecture through BoneJ pluging and ImageJ script. Three histological processing of samples, including von Kossa silver nitrate, toluidine blue, and fluorescence by the deposition of calcein were utilized. RESULTS: Zn-membranes (Zn-Ms) promoted the highest amount of new bone and higher bone perimeter than both unloaded and Ti-membranes (Ti-Ms). Ca-membranes (Ca-Ms) attained higher osteoid perimeter and bone perimeter than Zn-Ms. The skeleton analysis showed that Zn-Ms produced more branches and junctions at the trabecular bone than BMP-loaded membranes (BMP-Ms). Samples treated with Ti-Ms showed less bone formation and bony bridging processes. Both Zn-Ms and Ca-Ms achieved higher number of osteoblasts than the control group. BMP-Ms and Ca-Ms originated higher number of blood vessels than Ti-Ms and control group. CONCLUSIONS: Zn incorporation in novel nanostructured membranes provided the highest regenerative efficiency for bone healing at the rabbit calvarial defects. CLINICAL RELEVANCE: Zn-Ms promoted osteogenesis and enhanced biological activity, as mineralized and osteoid new bone with multiple interconnected ossified trabeculae appeared in close contact with the membrane.

Prospective observational cohort study of the change of the marginal bone crest in relation to the prosthetic abutment height and the peri-implant vertical mucosal thickness at implants positioned subcrestally.

AIM: To evaluate the influence on peri-implant crestal bone loss exerted by the vertical mucosal thickness and the abutment height over 12 months after placement of the restoration on subcrestal implants with change of platform, using a restoration abutment platform smaller than the implant platform. MATERIALS AND METHODS: A total of 99 implants were rehabilitated in the maxillary and mandibular posterior regions. A total of 22 implants were rehabilitated in the maxilla and 77 implants in the mandible, using digitally designed customized abutments with Atlantis weborder software, from the commercial house Dentsply Sirona (Dentsply Sirona S.A., Barcelona, Spain), version 4.6.5, adapting the height to the vertical thickness of the mucosa. Clinical and radiographic monitoring begins during the surgical procedure of placement of the implant and ends 12 months afterwards. Crestal bone loss was evaluated through the Carestream® CS8100 3D radiographic equipment. RESULTS: In all cases, the greatest loss of marginal bone occurred between the day of surgery (Tx) and placement of the rehabilitation (To). The average bone loss between both times was greater when the abutment height and vertical mucosal thickness did not exceed 3 mm. Subsequently, bone loss slowed and stabilized at 12 months. CONCLUSIONS: The minimum abutment height and the vertical mucosal thickness are factors to take into account when minimizing peri-implant marginal bone loss, the abutment height having the greatest importance according to the clinical data obtained.

Doped Electrospinned Material-Guides High Efficiency Regional Bone Regeneration.

The main target of bone tissue engineering is to design biomaterials that support bone regeneration and vascularization. Nanostructured membranes of (MMA)1-co-(HEMA)1/(MA)3-co-(HEA)2 loaded with 5% wt of SiO2-nanoparticles (Si-M) were doped with zinc (Zn-Si-M) or doxycycline (Dox-Si-M). Critical bone defects were effectuated on six New Zealand-bred rabbit skulls and then they were covered with the membranes. After six weeks, a histological analysis (toluidine blue technique) was employed to determine bone cell population as osteoblasts, osteoclasts, osteocytes, M1 and M2 macrophages and vasculature. Membranes covering the bone defect determined a higher count of bone cells and blood vessels than in the sham group at the top regions of the defect. Pro-inflammatory M1 appeared in a higher number in the top regions than in the bottom regions, when Si-M and Dox-Si-M were used. Samples treated with Dox-Si-M showed a higher amount of anti-inflammatory and pro-regenerative M2 macrophages. The M1/M2 ratio obtained its lowest value in the absence of membranes. On the top regions, osteoblasts were more abundant when using Si-M and Zn-Si-M. Osteoclasts were equally distributed at the central and lateral regions. The sham group and samples treated with Zn-Si-M attained a higher number of osteocytes at the top regions. A preferential osteoconductive, osteoinductive and angiogenic clinical environment was created in the vicinity of the membrane placed on critical bone defects.

Detection of NOTCH1 mutations in paraffin samples in patients with potentially malignant lesions.

Background: On certain occasions, oral cancer is preceded by potentially malignant lesions. The degree of dysplasia in Guinea pigs attempts to determine the risk of developing a malignant lesion. The search for genetic mutations, biomarkers, as a more truthful and reproducible diagnostic tool, tries to fill the gaps in the anatomopathological study. In this line, the present retrospective case-control study is based on the detection of known mutations of the NOTCH1 gene in biopsied samples of potentially malignant lesions from 22 patients who attend the Oral and Maxillofacial Surgery service of the Virgen del Rocío University Hospital. Material and Methods: DNA extraction after dewaxing of the samples using the Minikit QIAamp DNA FFPE tissue extraction kit with extraction kit (reference 56404) of QIAGEN. Subsequently, with the DNA obtained, 4 amplification reactions were carried out using enzyme polymerase. Before sequencing the samples, they were purified with the ExoSAP-IT for PCR product cleaning kit of the INVITROGEN brand. Finally, to detect somatic mutations in NOTCH1, TaqMan Mutation Detection Assays was used and for the analysis of mutations we worked with the Mutation Detector software. Results: The mutation for NOTCH1 is not detected, the studied sample does not present the mutation, or it is below the limits of detection of the software. Conclusions: In the clinical setting of the sample, the NOTCH1 mutation seems to be not very frequent, although NOTCH1 has been described as a gene related to oral cancer in other geographical settings. Key words:Oral cancer, NOTCH1, mutations.

Histomorphometric Analysis of Differential Regional Bone Regeneration Induced by Distinct Doped Membranes.

Our objective is to evaluate the regional regenerative potential of calvarial bone in critical-sized defects in a rabbit model using novel nanostructured silica-loaded membranes doped with zinc or doxycycline. Nanostructured membranes of (MMA)1-co-(HEMA)1/(MA)3-co-(HEA)2 loaded with 5 wt% of SiO2 nanoparticles (HOOC-Si-Membranes) were doped with zinc (Zn-HOOC-Si-Membrane) or doxycycline (Dox-HOOC-Si-Membrane). Critical bone defects were created on six New-Zealand-breed rabbit skulls and covered with the membranes. A sham defect without a membrane was used as the control. After six weeks, a histological analysis (toluidine blue technique) was employed to determine the area percentages of newly formed bone, osteoid bone, and soft tissue. The measurements were performed by dividing the total defect area into top (close to the membrane) and bottom (close to the dura mater) regions, or peripheral (adjacent to the old bone) and central (the sum of the remaining zones) regions. The peripheral regions of the defects showed higher osteogenic capacity than the central areas when the membranes were present. The proportion of new bone adjacent to the dura was similar to that adjacent to the membrane only when the HOOC-Si-Membranes and Zn-HOOC-Si-Membranes were used, indicating a direct osteoinductive effect of the membranes.

Mutations in p53 Gene Exons in a Sample from the South of Spain in Oral Cancer.

BACKGROUND: Cancer is a genetic disease caused by mutations in DNA and epigenetic alterations that control gene expression. The majority of epidermoid carcinomas develop within the fields of epithelial genetic alterations. The mechanisms underlying tumorigenesis of epidermoid carcinoma are as yet unknown; therefore, precise identification of the risk factors is needed. Aim: The main aim of this study is to analyse and identify the emergence of the mutations described in the literature of the p53 gene with regard to the emergence of cancer in a sample of dysplastic and cancerous lesions in oral cavity mucosa in the population of the south of Spain, in order to determine the presence of said mutations and the percentage of them in our population. MATERIAL AND METHODS: A cross-sectional study was carried out, with a sample size of 22 patients with potentially malignant oral lesions ancillary to biopsy. All were patients, of both sexes, over 18 years of age from the Virgen del Rocío University Hospital with potentially malignant lesions in oral mucosa ancillary to biopsy (leukoplakias, erythroplasias or leukoerythopkias). An anatomopathological study was performed on all the samples and the lesions were divided into three types: low-grade dysplasia, high-grade dysplasia and squamous cell carcinoma. In respect of the genome study process, a complete search or scan for mutations in exons 5, 6, 8 and 9 of the p 53 gene was carried out, given that in the IARC database we observed that the 5 and 6 as well as the 8 and 9 exon sizes can be scanned completely in this way, since they have amplificon sizes of 476 and 445 base pairs respectively. RESULTS: In the scan for the complete exons 5, 6, 8 and 9 only a single result of interest was found to be described. In patient NBI 57 a change was observed in the TAT triplet by ATT of EXON 6, the change being of the T nucleotide by the A and in both directions both in Forward and Reverse. The exact location in the NCBI is GR Ch 37 p13 on chromosome 17, EXON 6 of the P53 gene and the change is in the C.613 T>A nucleotide; NM_000546. CONCLUSIONS: On reviewing this genetic variant in different scientific databases, such as ENSEMBL among others, in at least 6 different biocomputing tools it is described as a pathogen, therefore we can conclude that it is a pathogenic mutation for this case in particular. The rest of the mutations described in the literature on exons 5, 6, 8 and 9 of the p53 gene have not been found in our sample. Key words:Oral cancer, p53, Mutations, Exon.

Doxycycline and Zinc Loaded Silica-Nanofibrous Polymers as Biomaterials for Bone Regeneration.

The main target of bone tissue engineering is to design biomaterials that support bone regeneration and vascularization. Nanostructured membranes of (MMA)1-co-(HEMA)1/(MA)3-co-(HEA)2 loaded with 5% wt of SiO2-nanoparticles (HOOC-Si-Membrane) were doped with zinc (Zn-HOOC-Si-Membrane) or doxycycline (Dox-HOOC-Si-Membrane). Critical bone defects were effectuated on six New Zealand-bred rabbit skulls and covered with the membranes. After six weeks, the bone architecture was evaluated with micro computed tomography. Three histological analyses were utilized to analyse bone regeneration, including von Kossa silver nitrate, toluidine blue and fluorescence. All membrane-treated defects exhibited higher number of osteocytes and bone perimeter than the control group without the membrane. Zn-HOOC-Si-Membranes induced higher new bone and osteoid area than those treated with HOOC-Si-Membranes, and control group, respectively. Zn-HOOC-Si-Membranes and Dox-HOOC-Si-Membranes attained the lowest ratio M1 macrophages/M2 macrophages. Dox-HOOC-Si-Membranes caused the lowest number of osteoclasts, and bone density. At the trabecular new bone, Zn-HOOC-Si-Membranes produced the highest angiogenesis, bone thickness, connectivity, junctions and branches. Zn-HOOC-Si-Membranes enhanced biological activity, attained a balanced remodeling, and achieved the greatest regenerative efficiency after osteogenesis and angiogenesis assessments. The bone-integrated Zn-HOOC-Si-Membranes can be considered as bioactive modulators provoking a M2 macrophages (pro-healing cells) increase, being a potential biomaterial for promoting bone repair.

Evolution of oral health in oral cancer patients with and without dental treatment in place: Before, during and after cancer treatment.

BACKGROUND: This study aims to evaluate the influence of two dental treatment protocols, outpatient non-regulated treatment versus supervised hospital treatment, on the oral health of patients undergoing oral cancer (only radiochemotherapy treatment, not surgical) treatment. MATERIAL AND METHODS: The study used a quasi-experimental approach justified on ethical grounds. A total of 41 patients were included in the control group (outpatient non-regulated treatment) and 40 patients in the experimental group (in-hospital supervised treatment). The patients were treated only with chemotherapy (not surgical treatment was made) for oral cancer. This decision was taken by the oncology committee of the hospital without being influenced by this study. Data regarding plaque index, daily brushing habits, appearance of new cavities, need for extractions, appearance of candidiasis and use of prosthetics in both groups were collected at three points throughout the study: before starting cancer treatment, during treatment and after treatment. The values obtained using the Student's t-test and chi-squared were compared. RESULTS: Based on similar patient backgrounds, throughout cancer treatment the intervention under study resulted in a decrease in plaque index, necessary extractions, and incidence of decay, as well as an increase in daily brushing among other improvements in oral health observed in the experimental group versus the control group. CONCLUSIONS: From our data, we can confirm that supervised dental treatment performed during oral cancer treatment produced an improvement in the oral health of patients with oral cancer. Key words:Oral cancer, dental treatment, quality of life, oncology, dentistry.

Ability of salivary biomarkers in the prognostic of systemic and buccal inflammation.

Nowadays, there is a growing interest in using saliva as an alternative sample for the diagnosis, prediction and progression of several diseases. It has been established that some molecules found in saliva are related to oral inflammatory processes and systemic health status. Furthermore, it is known that saliva is crucial for the carrying out of different functions in the oral cavity and its role in the local modulation of inflammatory and immune response is being thoroughly studied by the health research community. The aim of this review is to analyze the most important biomarkers which have been utilized in biomedicine during the last two decades in order to establish a correlation between certain specific salivary biomarkers and systemic inflammation. Then, we discuss the utility of total proteins, immunoglobulin A and alpha-amylase as biomarkers for the prognostic of local inflammation after oral surgery. Key words:Inflammation, salivary biomarkers, systemic disease, buccal surgery, total proteins, inmunoglobulin A, Alpha-amylase.

Prophylaxis and antibiotic therapy in management protocols of patients treated with oral and intravenous bisphosphonates.

INTRODUCTION: Osteonecrosis of the jaw (MRONJ) linked to bisphosphonate treatment has specific characteristics that render its therapeutic management challenging for clinicians. Poor response to standard treatment makes it essential to take special precautions when treating this type of disease; therefore, antibiotic prophylaxis and/or antibiotic therapy have been proposed as effective and helpful tools in these situations. OBJECTIVES: This article seeks to assess published evidence in order to evaluate the different protocols used for antibiotic prophylaxis and/or antibiotic therapy in the general context of patients treated with bisphosphonates. MATERIAL AND METHODS: A literature review of the last 10 years was carried out in PubMed using the following keywords: "antibiotic prophylaxis and osteonecrosis," "bisphosphonates AND osteonecrosis AND dental management," "bisphosphonate AND osteonecrosis AND antibiotic prophylaxis AND oral surgery." A total of 188 articles were obtained, of which 18 were ultimately selected. RESULTS AND DISCUSSION: In patients treated with oral and intravenous bisphosphonates without chemotherapy-associated osteonecrosis of the jaw, antibiotic prophylaxis prior to oral surgery is an important tool to avoid osteonecrosis and promote healing of the affected area. If the patient previously exhibited chemotherapy-associated osteonecrosis after tooth extraction, antibiotic prophylaxis is indicated to prevent recurrent osteonecrosis and promote healing of the extraction site. If chemotherapy-associated osteonecrosis is already present, antibiotic therapy is a vital part of conservative management to reduce the symptomatology of MRONJ and keep it from worsening. Finally, a lack of clinical data and randomized controlled trials makes it difficult to choose the most appropriate protocol for the various clinical situations studied. Key words:Bisphosphonates, antibiotic prophylaxis, maxillary osteonecrosis, antibiotic treatment.

Evolution of oral cancer treatment in an andalusian population sample: Rehabilitation with prosthetic obturation and removable partial prosthesis.

BACKGROUND: Radical surgical resection as a treatment modality for oral cancer often leads to an extensive deficit in both the maxillary and mandibular levels, where the use of a palatal obturator prosthesis (POP) or removable partial denture (RPP). The aim of this study was to evaluate the treatment with POP and RPP in patients treated for oral cancer in the Unit of Prosthetic Rehabilitation of the University Hospital Virgen del Rocío in a period of 20 years. MATERIAL AND METHODS: Retrospective descriptive study during the years 1991 and 2011 analyzing oral cancer type, characteristics, treatment and follow-up. The sample consisted of patients whose tumor had previously been removed and who had been referred to the Oncological Rehabilitation Unit of the Oral and Maxillofacial Surgery Unit of the "Virgen del Rocío" University Hospital for rehabilitation. The inclusion criteria were patients whose underlying pathology was any type of neoplasia, which after its treatment had been referred to the aforementioned Oncological Prosthetic Rehabilitation unit. RESULTS: Of the 45 patients included in our study, 15 patients were rehabilitated with palatal obturator (33.3%) and 5 patients with removable partial denture (11.1%). The mean age of the sample of patients with POP was 57.3 ± 9.23, while the mean age of the sample of patients with RPP was 58 ± 13.5. The most common underlying pathology in patients with POP was squamous cell carcinoma (60%), whereas in patients with RPP it was 100%. The most frequent location found among POP patients was the upper jaw, while in the PRP patients there was no predominant location. The univariate and multivariate logistic regressions did not show any statistically significant association between the independent variables age, sex, smoking habit and alcoholic habit with the dependent variable type of rehabilitating prosthesis. CONCLUSIONS: Based on our data, we can conclude that RPP is used in few cases of oncological rehabilitation. The POP has a greater use, as long as the defect in the bones of the facial middle third is limited. Key words:Head and neck cancer, reconstructive surgery, Palatal obturators, removable partial dentures.

Pathogenesis and clinicohistopathological caractheristics of melanoacanthoma: A systematic review.

INTRODUCTION: The melanoacanthoma is a rare benign pigmented tumor, characterized by a fast radial growth and clinical behavior similar to melanoma. Color changes in oral mucosa and dermis are consequence of increased melanocyte activity as response to an irritant factor. There is a vast phenotypic variety. It is difficult to distinguish between a benign pigmented lesion and a melanoma at its early stage. Due to its clinical relevance is crucial to diagnose possible malignancy of the lesions. OBJECTIVES: The aim of this article is to conduct a systematic review of all published articles, as well as update and evaluate etiologic factors and clinicopathological features. MATERIAL AND METHODS: We carried out a search in the Medline database (PubMed) using the key words "oral melanoacanthoma" AND "oral melanoacanthosis" AND "oral melanoepithelioma". Inclusion criteria were all published articles since its discovery. Demographic data, histological features and immunohistochemical findings were extracted from the full articles. RESULTS: A total of 56 articles were analysed. 114 injuries drawn from these articles were studied, a total of 115 injuries with our contribution case. The 74.78% of authors claim a reactive pathogenesis. The average age of lesión appearance is 34.79 years, with an age range of 5-87 years. There is a predominance of the female sex in solitary phenotype 3: 2 and a ratio of women to men 5: 3 if it is multifocal phenotype. Bilateral phenotype is slight higher in women of 2: 1. CONCLUSIONS: Histopathological analysis of the lesión is vital to diagnose malignancy. Therefore, any heterogeneous, pigmented lesion with irregular edges, raised surface, fast growth and abrupt appearance should be biopsied. More emphasis on the potential irritants should also be put to improve the quality of life of our patients and to reduce morbidity of melanoacanthoma, as well as, several similar clinical behavior disease. KEY WORDS: Melanoacanthoma, oral cáncer, diagnosis.