Mapping Bone Marrow Cell Response from Senile Female Rats on Ca-P-Doped Titanium Coating.

Chemical and topographical surface modifications on dental implants aim to increase the bone surface contact area of the implant and improve osseointegration. This study analyzed the cellular response of undifferentiated mesenchymal stem cells (MSC), derived from senile rats' femoral bone marrow, when cultured on a bioactive coating (by plasma electrolytic oxidation, PEO, with Ca2+ and P5+ ions), a sandblasting followed by acid-etching (SLA) surface, and a machined surface (MSU). A total of 102 Ti-6Al-4V discs were divided into three groups (n = 34). The surface chemistry was analyzed by energy dispersive spectroscopy (EDS). Cell viability assay, gene expression of osteoblastic markers, and mineralized matrix formation were investigated. The cell growth and viability results were higher for PEO vs. MSU surface (p = 0.001). An increase in cell proliferation from 3 to 7 days (p < 0.05) and from 7 to 10 days (p < 0.05) was noted for PEO and SLA surfaces. Gene expression for OSX, ALP, BSP, and OPN showed a statistical significance (p = 0.001) among groups. In addition, the PEO surface showed a higher mineralized matrix bone formation (p = 0.003). In conclusion, MSC from senile female rats cultured on SLA and PEO surfaces showed similar cellular responses and should be considered for future clinical investigations.

Evaluation of Guided Bone Regeneration in Critical Defects Using Bovine and Porcine Collagen Membranes: Histomorphometric and Immunohistochemical Analyses.

Guided bone regeneration (GBR) is a technique used to facilitate bone regeneration, which uses a biocompatible membrane acting as a physical barrier to prevent the adjacent connective tissue from invading the bone defect. The aim of this study was to evaluate and compare the effectiveness of bovine and porcine collagenous membranes as barriers to connective tissue invasion during the repair of critical bone defects in rat calvaria, using histological, histometric, and immunohistochemical analyses. For this study, 72 rats were divided into three groups: clot group (CG), bovine collagen group (BCG), and porcine collagen group (PCG). Analyses were performed on days 7, 15, 30, and 60. The histological results showed that the PCG exhibited bone neoformation starting from day 7, and after 30 days of repair, the surgical defect was completely filled in some animals. For the BCG, there was little bone neoformation activity in the initial periods, and from day 30 onwards, there was an increase in bone neoformation, with a greater increase on day 60. The data obtained in the histometric analysis reveal that, on day 30, the neoformed bone area did not vary greatly between the PCG and the BCG, though both varied from the CG. By day 60, the PCG presented a greater area of neoformation than the BCG. These results were corroborated by the immunohistochemistry results. In view of the results obtained, it can be concluded that all membranes studied in this research promoted GBR.

Combination of etodolac and dexamethasone improves preemptive analgesia in third molar surgery: a randomized study.

OBJECTIVE: This randomized, controlled, triple-blind, crossover clinical trial aimed to investigate the use of dexamethasone (DEX) and etodolac (ETO) as preemptive analgesia before mandibular third molar extraction. METHODS: Patients were divided into three groups (n = 20 teeth each) based on the drug administered: DEX 8 mg (DEX); DEX 8 mg plus ETO 300 mg (DEX + ETO), and ETO 300 mg (ETO). Paracetamol (750 mg) tablets were administered as rescue analgesics. Pain was evaluated using the visual analog scale (VAS) at 6, 12, 24, 48, and 72 h and 7 days postoperatively. Edema and trismus were assessed 48 and 72 h postoperatively. All data were subjected to statistical analysis, where a P value < .05 indicated statistical significance. RESULTS: VAS scores and the number of rescue analgesics taken were lower in the DEX + ETO group than in the other groups (P < .001 and P = .014, respectively). At 48 h, trismus was similar among all groups; however, the ETO group showed the highest trismus 7 days postoperatively (P < .05). Edema was similar among all groups at all time points (P > .05). CONCLUSION: The combined use of the anti-inflammatory drugs, DEX and ETO, resulted in better pain control and the need for fewer rescue analgesics than the use of either drug alone, which indicated their effectiveness in mandibular third molar extractions preoperatively. CLINICAL RELEVANCE: This drug combination can lead to less pain, edema, and trismus and reduce the use of rescue analgesics in the postoperative period.

Bone formation around two titanium implant surfaces placed in bone defects with and without a bone substitute material: A histological, histomorphometric, and micro-computed tomography evaluation.

OBJECTIVE: To evaluate the histological and microtomographic response of peri-implant bone tissue around titanium implants with different surface treatments, placed in bone defects filled or not filled with bone substitute materials. MATERIALS AND METHODS: Thirty rabbits were divided into two groups according to the implant surface treatment. A bone defect was created in both tibias of all the rabbits, followed by the placement of one implant in each of these defects. On the left tibia, the defect was filled with a blood clot (BC), and on the right tibia, the defect was filled with biphasic hydroxyapatite/ß-tricalcium-phosphate (HA/TCP); thus, there were four groups in total: BC-N: bone defect filled with a BC and porous surface titanium implant (control group); BC-A: bone defect filled with a BC and porous-hydrophilic surface titanium implant; HA/TCP-N: bone defect filled with a bone substitute material and porous surface titanium implant; HA/TCP-A: bone defect filled with a bone substitute material and porous-hydrophilic surface titanium implant. The animals were submitted for euthanasia at three distinct periods: 15, 30, and 60 days after implant installation. The samples were evaluated histologically and histometrically, to assess the quantity and quality of cells and the remaining bone substitute material in the grafted areas. The bone quantity was assessed by micro-computed tomography (CT). RESULTS: For both surface types, the presence of a bone substitute material led to higher values in all evaluated micro-CT parameters, except in the bone surface/volume ratio parameter. No significant statistical difference was found for new bone formation between the four groups (P < .05; CI 95%). At all periods, the HA/TCP-A group had a higher percentage of new bone formation. CONCLUSION: These results suggest that a porous hydrophilic surface in the presence of bone substitute material can accelerate peri-implant bone tissue formation.

The Fresh Frozen Bone Allograft (FFBA) to Reconstruct the Atrophic Maxilla: Evaluation of the Clinical and Histological Viability at Six and Nine Months in the Maxillary Sinus / Aloinjerto Óseo Fresco Congelado (FFBA) en la Reconstrucción del Maxilar Atrófico: Evaluación de la Viabilidad Clínica e Histológica a los Seis y Nueve Meses en el Seno Maxilar

This work aimed to analyze clinically and histologically the allogen bone graft behavior at 6 and 9 months. A leukoderm, female, 55 years old patient sought dental care for oral rehabilitation with dental implants and implant supported fixed prosthesis in the maxilla. Bilateral sinus lifting procedure were performed in a same patient, the analysis were made after 6 and 9 months, respectively. At 6 months, there was lack of a better bone remodeling in the region, associated to the presence of fibrous connective tissue within the collected tissue, showing us that this is not the best stage of tissue maturation to place dental implants. The 9 months period showed an improvement, with a more organized bone tissue surrounding particles of homogenous bone, what possibly had increased implant stability at the time of surgery. There is no doubt about the increase of clinical applications of FFBA, but there are no studies available regarding the standardization of time to load implants inserted in allografts. So papers with long-term monitoring are necessary to eliminate questions that still remain to be answered.

El objetivo fue analizar clínica e histológicamente el injerto óseo alógeno a los 6 y 9 meses. Una paciente sexo femenino, leucoderma de 55 años de edad consultó por atención odontológica para la rehabilitación oral con implantes y prótesis fija implanto soportada en el maxilar. Procedimientos de elevación del seno maxilar bilateralmente fueron realizados en la misma paciente, y se hicieron los análisis después del sexto y noveno mes, respectivamente. Al sexto mes, se observó una remodelación ósea deficiente de la región asociada a la presencia de tejido conectivo fibroso en el tejido analizado, demostrando que no era la mejor etapa de maduración óseo para instalar los implantes. Al noveno mes se observo una mejora, con un tejido óseo mas organizado rodeando partículas de hueso homogéneo, el cual posiblemente incrementaría la estabilidad del implante en el momento de la cirugía. No hay dudas respecto del incremento de aplicaciones clínicas del FFBA, pero no hay estudios capaces de estandarizar el tiempo de carga de los implantes instalados sobre aloinjertos. Investigaciones con seguimientos a largo plazo son necesarios para eliminar las preguntas que aun se mantienen sin respuesta.