Vicente Vicente-Ortega

An experimental study of bisphosphonate-induced jaws osteonecrosis in Sprague-Dawley rats.

OBJECTIVE Patients undergoing treatment with bisphosphonates may develop jaw lesions consisting mainly of bone necrosis. The present study describes a model of maxillary osteonecrosis in Sprague-Dawley rats, applying bisphosphonates and examines the changes occurring after tooth extraction. MATERIAL AND METHODS A total 200 animals were included in a randomized prospective study involving the following groups: group I (control, 20 rats without drug treatment), group II (60 animals administered dexamethasone 1 mg/kg/day for 7, 14 and 21 days, in subgroups of 20 animals each), group III (60 animals administered pamidronate daily at a dose of 3 mg/kg) and group IV (60 animals administered pamidronate and dexamethasone). In all groups, molar extraction was carried out on the right upper maxillary or mandibular side 8, 15 and 22 days after the start of dosing. The rats were killed 14 and 28 days after extraction in all groups. RESULTS A total of 18 cases of osteonecrosis were recorded in the group administered pamidronate and dexamethasone. Osteonecrosis affected the upper maxilla in 10 cases and the mandible in eight cases, and was circumscribed to the extraction zone in all cases. Osteonecrosis was not seen in any of the other groups. CONCLUSIONS The administration of pamidronate and dexamethasone in rats subjected to molar extraction increases the risk of osteonecrosis.

Perioperative antibiotic regimen in rats treated with pamidronate plus dexamethasone and subjected to dental extraction: a study of the changes in the jaws.

PURPOSE Osteonecrosis of the jaws is a well-known condition associated with long-term bisphosphonate use. This study analyzed the prophylactic effect of antibiotic treatment in Sprague-Dawley rats treated with pamidronate plus dexamethasone and subjected to oral surgery in the form of dental extraction. MATERIALS AND METHODS One hundred twenty animals were included in a randomized prospective study. Animals in group I (n = 60) were treated with dexamethasone 1 mg/kg and pamidronate 3 mg/kg 3 times per week for 7, 14, and 21 days. All were subjected to right mandibular or maxillary molar extraction 8, 15, and 22 days after the start of dosing. Animals in group II (n = 60) received the same treatment except for the addition of penicillin 0.1 mL/kg per day for 3 days before and 4 days after extraction. Rats in the 2 groups were sacrificed 14 and 28 days after extraction. A clinical and histologic evaluation was performed. RESULTS In group I, osteonecrosis was documented in 18 cases (34.6%; affecting the upper and lower jaws in 10 and 8 cases, respectively). In group II, osteonecrosis was documented in 5 cases (9.61%; affecting the upper and lower jaws in 3 and 2 cases, respectively). The difference between the 2 groups was statistically significant (P = .002). CONCLUSIONS The adoption of preventive measures (antibiotic prophylaxis) in invasive dental procedures results in a significant decrease in osteonecrosis of the jaws associated with bisphosphonate use.

Oral and facial piercings: a case series and review of the literature

Introduction  Piercing is popular among young people, who view this practice as a sign of marginality, beauty, or group identity. This study is performed on healthy individuals with oral and facial piercings.

In‐vivo behavior of Si‐hydroxyapatite/polycaprolactone/DMB scaffolds fabricated by 3D printing

Scaffolds made of polycaprolactone and nanocrystalline silicon-substituted hydroxyapatite have been fabricated by 3D printing rapid prototyping technique. To asses that the scaffolds fulfill the requirements to be considered for bone grafting applications, they were implanted in New Zealand rabbits. Histological and radiological studies have demonstrated that the scaffolds implanted in bone exhibited an excellent osteointegration without the interposition of fibrous tissue between bone and implants and without immune response after 4 months of implantation. In addition, we have evaluated the possibility of improving the scaffolds efficiency by incorporating demineralized bone matrix during the preparation by 3D printing. When demineralized bone matrix (DBM) is incorporated, the efficacy of the scaffolds is enhanced, as new bone formation occurs not only in the peripheral portions of the scaffolds but also within its pores after 4 months of implantation. This enhanced performance can be explained in terms of the osteoinductive properties of the DBM in the scaffolds, which have been assessed through the new bone tissue formation when the scaffolds are ectopically implanted.

The use of plasma rich in growth factors on wound healing in the skin: experimental study in rabbits

The objective of this study was to use autologous plasma rich in growth factors (PRGF) on wound healing in the skin in New Zealand albino rabbits and to study reepithelialisation and inflammation at 7 and 28 days. A prospective study carried out on 20 adult rabbits. Two wounds were made on the in the skin on the back of each animal; one control, and the other in which PRGF was applied. The PRGF preparation was obtained from 10 ml of whole blood. The reepithelialisation and inflammation of wounds were measured at 7 and 28 days. Reepithelialisation improved in skin at 7 days (P = 0·007), with resolution of the inflammatory process (P = 0·005), having significant differences with respect to the control. Therefore, PRGF accelerates reepithelialisation and reduces inflammation at 7 days in skin.

Plasma rich in growth factors and bone formation: a radiological and histomorphometric study in New Zealand rabbits

A radiographic and histomorphometric study was conducted on the influence of autologous plasma rich in growth factors (PRGF) upon bone healing in surgically created defects in rabbits. Radiographically, bone regeneration was significantly greater with the use of PRGF after one month (p = 0.005), though no differences were recorded after the second month. In the histomorphometric analysis one month after surgery, the defects filled with autologous bone plus PRGF showed a greater percentage of neoformed bone (35.01 +/- 5.31) than the control defects (22.90 +/- 12.23), though the differences were not significant. Two months after surgery, the defects filled with autologous bone showed greater regeneration (46.04 +/- 10.36%) than the control defects (30.59 +/- 5.69%), though the differences were not significant. The application of PRGF in the bone defects produced in New Zealand rabbits exerted a limited effect on local bone formation.

Radioprotective effects of lycopene and curcumin during local irradiation of parotid glands in Sprague Dawley rats

Radiotherapy effectively treats cancers of the head and neck. We investigated the possible protective effects of lycopene and curcumin on the parotid glands of 40 female Sprague Dawley rats during irradiation. The study followed European Union regulations 86/609/EEC, 2010/63/EU for animal experimentation. The animals were divided into 4 groups: those treated with curcumin and radiation, those treated with lycopene and radiation, those treated with dimethyl sulphoxide (DMSO) and radiation, and those treated with radiation alone. All compounds were given intraperitoneally the day before irradiation. The total dose of radiation was 20Gy. Morphological and histopathological analyses showed less cell necrosis in the group treated with curcumin than in the other groups, but the difference was not significant. Analysis of structural damage to the parotid ducts and vacuolisation showed significant differences among all groups (p=0.023, p<0.01). Lycopene and curcumin given 24 hours before irradiation reduced the structural damage to the salivary glands. Further studies are needed to confirm these findings.

Effects of potassium apigenin and verbena extract on the wound healing process of SKH-1 mouse skin

Tissue repair is a complex process, which may be favoured or inhibited by different factors. Potassium apigenin (AP) and other flavonoids present in verbena extract (PLX®) possess powerful anti‐inflammatory properties. The aim of this study was to evaluate the effects of topical treatment with AP and PLX gels on wounds inflicted on SKH‐1/CRL mice. Forty‐eight SKH‐1 mice were used (4 groups with 12 animals each), which were subjected to wound excision with a round scalpel, 4 mm in diameter, on the dorsal skin. The animals were divided into four groups: Group I received topical applications of apigenin gel; Group II received PLX gel; Group III received vehicle gel; Group IV acted as control. Wound contraction, reepithelialisation, inflammation and neovascularisation (by means of immunohistochemical staining with anti‐laminin) were recorded at study periods established at 2, 7 and 14 days. Reepithelialisation was faster in Groups I and II at 7 days (56·25% grade 3 and 43·75% grade 4) compared with the other groups. The degree of inflammation showed improvement with a tendency towards statistical significance in Groups I and II at 2 and 7 days. Anti‐laminin staining was more intense in the group treated with PLX at the 2‐ and 7‐day periods. Topical treatment with PLX gel improved the degree of reepithelialisation and inflammation, and favoured neo‐vascularisation of the wounds at 2 and 7 days following surgery.

Chemopreventive potential of phenolic compounds in oral carcinogenesis.

OBJECTIVE To evaluate the chemopreventive potential of phenolic compounds - potassium apigenin, cocoa, catechins, eriocitrin and rosmarinic acid in oral carcinogenesis induced in hamsters by means of the topical application of 7,12-dimethylbenz(a)anthracene(DMBA). STUDY DESIGN An experimental study at the University of Murcia. METHODS 50 male Syrian hamsters (Mesocricetus auratus) were divided into five groups of ten: Group I (control group): 0.5% DMBA; Group II: 0.5% DMBA+1.1mg/15ml potassium apigenin; Group III: 05% DMBA+2.5mg/15ml cocoa catechins; Group IV: 0.5% DMBA+6mg/15ml eriocitrin; Group V: 0.5% DMBA+1.3mg/15ml rosmarinic acid. The flavonoids were administered orally. All the animals were sacrificed after 12 weeks. Macroscopic, microscopic and immunohistochemical (PCNA and p53) analyses of the lesions were performed. RESULTS All the groups treated with phenolic compounds showed lower incidences of tumour, greater differentiation and lower scores in the tumour invasion front grading system in comparison with the control group. Potassium apigenin and rosmarinic acid achieved the best results, the former considerably reduced the carcinoma tumour volumes developed and both significantly reduced the intensity and aggression of the tumours. Immunoexpression of PCNA and p53 were significantly altered during DMBA-induced oral carcinogenesis. CONCLUSIONS Animals treated with phenolic compounds, particularly potassium apigenin and rosmarinic acid, showed a lower incidence of tumours.

In vivo treatment of melanoma (B16F10) with a homeopathic agent and with a cytokine (IFN-α)

Among the numerous agents tested on melanoma, cytokines have attracted much attention over recent decades, in particular interferon-alpha (IFN-alpha). However, in a small number of experimental assays, homeopathic products have also been used. This study aimed to analyze the effects of INF-alpha and Lymphomyosot, administered individually or in combination, on the growth of B16F10 melanoma transplanted in C57BL/6J mice. Two experiments were performed using 72 young male mice, treated with 1 x 10(6) B16F10 cells and treated with phosphate-buffered saline (I), INF-alpha (II), Lymphomyosot (III), and both INF-alpha and Lymphomyosot (IV). Subsequent morphological and immunohistochemical studies were performed. All treatments produced a reduction in tumor weight with significant differences in those treated with INF-alpha and Lymphomyosot. INF-alpha reduced the cell proliferation index and the spread of inflammatory infiltrates and produced an increase in the extent of intratumoral necrosis. An antitumour effect was displayed by both agents, as was the cytotoxicity of INF-alpha and the immune response-stimulating effect of Lymphomyosot.