Production of bone mineral material and BMP-2 in osteoblasts cultured on double acid-etched titanium.

BACKGROUND: The study of osteoblasts and their osteogenic functions is essential in order to understand them and their applications in implantology. In this sense, this study try to study BMP-2 production and bone matrix deposition, in addition to other biological variables, in osteoblasts cultured on a rough double acid-etched titanium surface (Osseotite®, Biomet 3i, Palm Beach Garden, Florida, USA) in comparison to a smooth titanium surface (machined) and a control Petri dish. MATERIALS AND METHODS: An in vitro prospective study. NHOst human osteoblasts from the femur were cultured on three different surfaces: Control group: 25-mm methacrylate dish (n = 6); Machined group: titanium discs with machined surface (n = 6) and Experimental group: titanium discs with a double acid-etched nitric and hydrofluoric Osseotite® acid surface (n = 6). A quantification of the mitochondrial membrane potential, and studies of apoptosis, mobility and adhesion, bone productivity (BMP-2) and cellular bone synthesis were carried out after culturing the three groups for forty-eight hours. RESULTS: A statistically significant difference was observed in the production of BMP-2 between the experimental group and the other two groups (22.33% ± 11.06 vs. 13.10% ± 5.51 in the machined group and 3.88% ± 3.43 in the control group). Differences in cellular bone synthesis were also observed between the groups (28.34% ± 14.4% in the experimental group vs. 20.03% ± 6.79 in the machined group and 19.34% ± 15.93% in the control group). CONCLUSIONS: In comparison with machined surfaces, Osseotite® surfaces favor BMP-2 production and bone synthesis as a result of the osteoblasts in contact with it.

Reliability of new poly (lactic-co-glycolic acid) membranes treated with oxygen plasma plus silicon dioxide layers for pre-prosthetic guided bone regeneration processes.

BACKGROUND: The use of cold plasmas may improve the surface roughness of poly(lactic-co-glycolic) acid (PLGA) membranes, which may stimulate the adhesion of osteogenic mediators and cells, thus accelerating the biodegradation of the barriers. Moreover, the incorporation of metallic-oxide particles to the surface of these membranes may enhance their osteoinductive capacity. Therefore, the aim of this paper was to evaluate the reliability of a new PLGA membrane after being treated with oxygen plasma (PO2) plus silicon dioxide (SiO2) layers for guided bone regeneration (GBR) processes. MATERIAL AND METHODS: Circumferential bone defects (diameter: 11 mm; depth: 3 mm) were created on the top of eight experimentation rabbits' skulls and were randomly covered with: (1) PLGA membranes (control), or (2) PLGA/PO2/SiO2 barriers. The animals were euthanized two months afterwards. A micromorphologic study was then performed using ROI (region of interest) colour analysis. Percentage of new bone formation, length of mineralised bone, concentration of osteoclasts, and intensity of ostheosynthetic activity were assessed and compared with those of the original bone tissue. The Kruskal-Wallis test was applied for between-group com Asignificance level of a=0.05 was considered. RESULTS: The PLGA/PO2/SiO2 membranes achieved the significantly highest new bone formation, length of mineralised bone, concentration of osteoclasts, and ostheosynthetic activity. The percentage of regenerated bone supplied by the new membranes was similar to that of the original bone tissue. Unlike what happened in the control group, PLGA/PO2/SiO2 membranes predominantly showed bone layers in advanced stages of formation. CONCLUSIONS: The addition of SiO2 layers to PLGA membranes pre-treated with PO2 improves their bone-regeneration potential. Although further research is necessary to corroborate these conclusions in humans, this could be a promising strategy to rebuild the bone architecture prior to rehabilitate edentulous areas.

A Prospective, Double-Blind, Randomized, Controlled Clinical Trial in the Gingivitis Prevention with an Oligomeric Proanthocyanidin Nutritional Supplement.

AIM: To evaluate the effectiveness on tissue response of the new nutritional supplement made of oligomeric proanthocyanidins in induced gingivitis after 21 days of use. MATERIAL AND METHODS: A prospective, double-blind, randomized, controlled clinical trial was carried out on 20 patients; it is divided into an experimental group and a control group after fulfilling the selection criteria. Patients had to come 4 times during the study to register the Silness and Löe index, the gingival bleeding index, the plaque index, the inflammatory crevicular fluid study (IL6), and the changes in the brightness of the gingiva. No complementary hygiene methods were allowed during the 21 days. RESULTS: The Silness and Löe index was higher in the control group than in the experimental group, reaching a twofold difference between the groups (p < 0.0001). The gingival bleeding index also supports this fact, since the bleeding was lower in the experimental group (p < 0.005). However, the dental plaque on the tooth surface according to the plaque index was 33% higher in the experimental group (p < 0.006). Some differences in the IL-6 were found in the crevicular fluid (p < 0.0001). CONCLUSION: Oligomeric proanthocyanidins have an effect on the periodontal tissue's health. No effects on the accumulation of plaque on the tooth surface were found, so further studies are needed to determine the nature of the plaque.

Relationship between salivary biomarkers and postoperative swelling after the extraction of impacted lower third molars.

Many authors have studied various different parameters in relation to postoperative anxiety after the extraction of third molars. However, the effect that the acute inflammatory process occurring post extraction could have on these parameters has not been studied. Certain salivary biomarkers, although not specifically inflammatory, may be affected by the acute inflammatory process occurring following the extraction of a retained lower third molar. Three biomarkers were assessed in this study: total protein, immunoglobulin A (IgA), and alpha-amylase. A total of 15 patients were recruited. Four samples of saliva were taken from each patient: before extraction, immediately after extraction, at 2h after extraction, and at 7 days after extraction. The concentrations of the proteins in the saliva were measured. The average values of each marker were compared across the different stages of the study. Statistical analysis revealed that of the three salivary biomarkers, only alpha-amylase was associated with an inflammatory response to the surgery (P<0.05). These results suggest the possibility that salivary alpha-amylase levels may be affected by the acute inflammation occurring post extraction; therefore, this would not be an appropriate marker to use in the study of other situations, unless this interference is controlled for.