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.

Pulp Revascularization of Immature Dog Teeth with Apical Periodontitis Using Triantibiotic Paste and Platelet-rich Plasma: A Radiographic Study.

INTRODUCTION: This study evaluates radiographically the efficacy of 4 revascularization protocols in necrotic-infected immature dog teeth with apical periodontitis (AP). METHODS: Forty double-rooted immature premolar teeth from 4 female beagle dogs aged 5 months were used. Four teeth were left untouched as negative controls; the other 36 teeth were infected to develop pulp necrosis and AP following different treatment protocols. Four teeth were left untreated and assigned to the positive control group, and the last 28 teeth were randomly assigned into 4 experimental groups of 8 teeth: A1, sodium hypochlorite (NaOCl) + a blood clot; A2, NaOCl + platelet-rich plasma (PRP); B1, NaOCl + modified triantibiotic paste (mTAP) + a blood clot; and B2, NaOCl + mTAP + PRP. Teeth were monitored radiographically for 6 months regarding healing of periapical radiolucencies, thickening of the dentinal walls, and apical closure of roots. RESULTS: Significant differences (P < .05) between the 4 groups were evident in the percentage of teeth showing improvement of periapical radiolucencies (62.5%), continued radiographic thickening of radicular walls (53.1%), radiographic apical closure (43.8%), and deposition of hard tissue on radicular dentin walls (53.1%). Group B2 showed maximal improvement in the 3 variables assessed (P < .05). Group A1 showed the minimum percentages in the 3 parameters assessed (P < .05). CONCLUSIONS: These results suggest that an intracanal dressing of mTAP and the use of PRP as scaffold improves the success rate of the revascularization procedure.

In vivo comparative model of oxygen plasma and nanocomposite particles on PLGA membranes for guided bone regeneration processes to be applied in pre-prosthetic surgery: a pilot study.

OBJECTIVES: To evaluate the bone regeneration potential of a new membrane fabricated with polyglycolide acid (PLGA) after being treated with oxygen plasma (PO2), and/or being functionalized with silicon dioxide (SiO2) or titanium dioxide (TiO2) nanoparticles. METHODS: Bone defects (5 mm 3 mm) were produced on the top of 3 experimentation rabbits' skulls and were covered with variously modified PLGA scaffolds. After the animals were sacrificed, neoformed bone (%), mineralized bone (mm), bone resorption (%), osteoclasts/mm2, and intensity of osteosynthetic activity, were assessed under microscope. RESULTS: The following groups were formed depending on the type of membrane: PLGA (control); PLGA/PO2; PLGA/SiO2; PLGA/TiO2; PLGA/PO2/SiO2; and PLGA/PO2/TiO2. The histological sections showed bone layers in advanced stages of formation. The highest percentages of neoformed bone corresponded to PLGA/PO2/SiO2 membranes (59.07%; p = 0.31) followed by PLGA/PO2 barriers (50.27%). The controls showed the lowest mineralization (13.89 mm; p = 0.24). PLGA/TiO2 scaffolds exhibited the least bone resorption (4.45%; p = 0.77) and osteoclasts/ mm2 (1.58; p = 0.86). PLGA/SiO2 and PLGA/TiO2 membranes stimulated the maximum osteosynthetic activity. CONCLUSIONS: The treatment of PLGA barriers with PO2 increased bone regeneration in rabbits. When comparing the effect of PO2/SiO2 and PO2/TiO2, higher percentages of neoformed bone were encountered after silicon-dioxide coating. CLINICAL SIGNIFICANCE: The incorporation of SiO2 nanoparticles onto PO2-treated PLGA membranes was the most promising technique out of those investigated to promote bone formation in rabbits. The addition of SiO2 or TiO2 layers to PLGA substrates may stimulate the osteosynthetic activity, which might be useful to restore bone dimensions in preparation for naturally appearing dental prostheses.

Treatment of a large maxillary cyst with marsupialization, decompression, surgical endodontic therapy and enucleation.

A large maxillary cyst was treated for 3 months with marsupialization and decompression, followed by surgical endodontic therapy of the affected teeth and cystectomy. Although small cystic lesions will typically heal with nonsurgical endodontic therapy, larger lesions may need additional treatment. Surgical enucleation of a large cystic lesion may lead to damage of other teeth or anatomic structures. Therefore, treatment should begin with the more conservative approach of decompression, to reduce the size of the lesion, followed by apicoectomy and cystectomy.

Pleomorphic adenoma of the parotid in childhood.

INTRODUCTION: Pleomorphic adenoma is a benign growth that most often appears in the parotid gland where it is the most frequent type of tumour. Its appearance in childhood is rare and there are no large series available in this age group for comparison with its presentation in adults. Surgical treatment is similar in children and in adults; whilst the prognosis is good, they may become malignant and metastasize. MATERIAL AND METHOD: In this study, we present seven parotid pleomorphic adenomas in childhood treated in our Department and a review of the literature. The following data were evaluated: sex, age, affected side, clinical symptoms and period of evolution of the symptoms, surgical technique applied and complications observed. RESULTS: The mean age at presentation was 12.4 years. All patients were males with the right side affected in five patients. The treatment was conservative superficial parotidectomy in five patients, conservative total parotidectomy in one, and an enucleation including a wide safety margin in the last case. None of the patients exhibited any permanent postoperative complication. The mean follow-up was 41.3 months (26-58 months).