Objectives: The cytotoxicity of the hydroxyapatite (HA) coating was investigated in vitro on murine fibroblast L929 and human liver carcinoma HepG2 cell lines. Methods: The titanium substrate surface was prepared by alkali etching with sodium hydroxide, subsequent replacement of Na+ with Ca2+ ions and thermal treatment at 600°C. Prepared specimens were used as a substrate for plasma jet deposition of HA. The plasma installation PJ-100TM/® was used for the plasma spray process. HA-coated samples and the titanium substrate underwent cytotoxic analysis. The cytotoxicity of both samples was tested in vitro on a single-layer cell culture by the direct contact method according to ISO-10993-5. For examination of the cytotoxic activity of both samples, L929 (murine fibroblast) and HepG2 (human liver carcinoma) cell lines were used. Experiments were performed with cells of viability of greater than 95% and cell confluence in a culture of 80%. The cytotoxicity investigation assessed metabolic activity using 3-[4,5 dimethyl-thiazol-2-lyl]- diphenyl tetrazolium bromide (MTT proliferative activity was measured by [3H]-thymidine incorporation; necrosis by lactate dehydrogenase (LDH) and propidium iodide (PI) assays; oxidative stress by nitrite measurement; and reactive oxygen species (ROS) by flow cytometry. Cell growth intensity and morphology were evaluated by phase contrast microscopy. Results: Adhesive strength of the HA coating was 60.5± 5.5MPa. X-ray diffraction showed mainly the presence of crystalline HA. Scanning electron microscopy revealed a very rough surface of the coating with micro and nano patterns. L929 cells were more sensitive than HepG2 cells in metabolic response to analysed samples. A statistically significant reduction of 20% was observed in metabolic activity for L929 cells cultured in the presence of both analysed samples compared to untreated cells. The samples showed different proliferative activity of L929 and HepG2 cells compared with untreated cells – L929 cell proliferation was significantly higher (15–20%) and HepG2 cell proliferation was significantly lower (20%). Morphological analysis of both cells lines showed no cytopathic effect of the tested samples in the immediate and distant areas of the sample in cell culture plate wells. After removing the samples, impaired confluence of cell growth on the plate surface was found beneath the sample, but reactivity was considered non-cytotoxic due to the limited area. LDH levels indicated the absence of (or very low) cytopathic effect of the analysed samples. Low cytotoxicity was confirmed by PI staining. There was no significant change in nitrite accumulation. A significantly higher production of ROS was observed in cultures of both cell lines in the presence of HA-coated samples. Conclusions: The changes in metabolic and proliferative activity of the cells in culture in the presence of HA samples were accompanied by an almost complete absence of cytopathy; metabolic activity and parameters of cell necrosis were significantly below 30% and the coating can be considered as non-cytotoxic, and therefor promising for biological applications. In terms of ROS production, HA modification of the titanium substrate increased the oxidative response of the tested cells, also without any cytopathic implications. The biological effects of HA coatings need to be further evaluated in vivo.

Objectives: The aim of this study was to evaluate clinical treatment of immediate dental implant placement of root fractures in adult patients following dentoalveolar trauma. Methods: A descriptive study was performed for cases of root fractures by systematic review of the digital records of all patients with dentoalveolar trauma and root fractures between May 2009 and May 2010 at the Unit of Oral and Maxillofacial Surgery, Hospital Clínico Mutual de Seguridad C.Ch.C., Santiago de Chile. Results: A total of 894 dentoalveolar trauma cases were identified, of which 56 (6.3%) were root fractures. In terms of outcome, implants had a 98% success rate, with no complications associated with vestibular bone loss or gingival unaesthetic recession. Conclusion: We believe that immediate replacement of lost teeth after root fractures with dental implants is a reliable option for patients with dental trauma, with no vestibular bone loss complications in the short term.

Objectives: To evaluate bony reconstruction of atrophic anterior maxilla using particulate grafts with or without autologous BMAC obtained via the BMAC method.
Methods: Patients with atrophic anterior maxillae due to tooth loss (n = 8) were selected and split into groups according to the type of material used: the control group (n=4) received particulate xenograft only, the test group (n= 4) received a combination of particulate xenograft and bone marrow aspirate concentrate obtained via the BMAC method. Both groups received a collagen membrane to cover the xenograft. After 4 months, during implant placement, a bony sample was removed from the graft area using a trephine bur with a 2-mm internal diameter. The specimens were fixed and preserved for histomorphometric assessment of the following tissues: vital mineralised tissue (VMT), non-vital mineralised tissue (NVMT) and non-mineralised tissue (NMT). Cone-beam CT (CBCT) was performed three times to measure bony thickness: (i) prior to graft insertion, (ii) 4 months after grafting, and (iii) 8 months after grafting. The parameter used was local bone gain in millimetres.
Results: Tomographic analysis revealed an increase in bony tissue in the CG of 3.78+1.35mm and 4.34+1.58mm at 4 months and 8 months, respectively. The TG showed an increase of 3.79+0.52mm and 4.09+1.33mm after 4 months and 8 months, respectively. Histomorphometric analysis revealed CG values for VMT, NMT and NVMT of 11.34±5.23%, 44.45±5.5% and 40.96±12.40%, respectively, and 64.31±9.12%, 32.41±10.38% and 0.73±0.56% for the TG.
Conclusions: The use of a bone marrow aspirate concentrate obtained via BMAC increased bone formation in the graft area in the anterior maxilla.