Single intraoperative infrared laser optimized bone repair in rat femoral osteotomies with experimentally induced osteoporosis

This study aimed to evaluate the effect of infrared laser (IRL) on bone repair in ovariectomized rats subjected to femoral osteotomies. Of 32 rats, half underwent bilateral ovariectomy (OVX) and the other half underwent sham ovariectomy (SHAM). A period of 3 months was defined to observe the presence of osteoporosis. The rats were subjected to osteotomies in the femurs and then fixed with a miniplate and 1.5-mm system screws. Thereafter, half of the rats from both SHAM and OVX groups were not irradiated, and the other half were irradiated by IRL using the following parameters: wavelength, 808 nm; power, 100 mW; 60 s for each point; 6 J/point; and a total of 5 points of bone gap. All animals were euthanized 60 days after surgery. The femur gap was scanned using micro-computed tomography (micro-CT). The samples were then examined under a confocal laser microscope to determine the amounts of calcein and alizarin red. The slides were stained with alizarin red and Stevenel's blue for histometric analysis. In the micro-CT analysis, the OVX groups had the lowest bone volume (P < 0.05). When the laser was applied to the OVX groups, bone turnover increased (P < 0.05). New bone formation (NBF) was comparable between SHAM and OVX/IR (P > 0.05) groups; however, it was less in the OVX groups (P < 0.05). In conclusion, the results encourage the use of IRL intraoperatively as it optimizes bone repair, mainly in animals with low bone mineral density.

Titanium Allergy Caused by Dental Implants: A Systematic Literature Review and Case Report

(1) Background: Hypersensitivity reactions to metals may arise in predisposed patients chronically exposed to metallic materials, including dental implants made of titanium alloys. The purpose of this article was to systematically review titanium allergy manifestations in patients treated with dental implants and report a clinical case; (2) Methods: A systematic electronic search was performed for articles published in the English language until July 2021. The following eligibility criteria were adopted: (1) Population: individuals undergoing titanium and/or titanium alloy implant-supported rehabilitations; (2) Exposure: peri-implant soft tissue reactions attributable to implant insertion; (3) Outcome: evidence of titanium allergy, diagnostic methods, and forms of resolution; (3) Results: The included studies, in summary, presented evidence that titanium should not be considered an inert material, being able to trigger allergic reactions, and may be responsible for implant failure. A 55-year-old male patient received 3 implants in the posterior region of the left mandible and presented an epulis-like lesion developed from the peri-implant mucosa. The immunohistochemical analysis of the biopsy specimen confirmed the initial diagnosis of allergic reaction to titanium; (4) Conclusions: Although the evidence is weak, and titanium allergy has a low incidence, hypersensitivity reactions should not be underestimated. A rapid and conclusive diagnosis is mandatory to prevent further complications.

Is an anodizing coating associated to the photobiomodulation able to optimize bone healing in ovariectomized animal model?

This in vivo study investigated whether the bioactivity of anodizing coating, produced by plasma electrolytic oxidation (PEO), on mini-plate in femur fracture could be improved with the association of photobiomodulation (PBM) therapy. From the 20 ovariectomized Wistar female rats, 8 were used for model characterization, and the remaining 12 were divided into four groups according to the use of PBM therapy by diode laser (808 nm; power: 100 mW; energy: 6.0 J; energy density: 212 J/cm²; power density: 3.5 W/cm²) and the type of mini-plate surface (commercially pure titanium mini-plate -cpTi- and PEO-treated mini-plate) as follow: cpTi; PEO; cpTi/PBM; and PEO/PBM. After 60 days of surgery, fracture healing underwent microstructural, bone turnover, histometric, and histologic adjacent muscle analysis. Animals of groups with PEO and PBM showed greater fracture healing than cpTi control group under histometric and microstructural analysis (P < 0.05); however, bone turnover was just improved in PBM's groups (P < 0.05). there was no difference between cpTi and PEO without PBM (P > 0.05). Adjacent muscle analysis showed no metallic particles or muscle alterations in all groups. PEO and PBM are effective strategies for bone repair in fractures, however their association does not provide additional advantages.

Plasma Electrolytic Oxidation as a Feasible Surface Treatment for Biomedical Applications: an in vivo study

OBJECTIVES

In this in vivo animal study, we evaluated the effect of plasma electrolytic oxidation (PEO) coating on the topographic and biological parameters of implants installed in rats with induced osteoporosis and low-quality bones.

MATERIALS AND METHODS

In total 44 Wistar rats (Rattus novergicus), 6 months old, were submitted to ovariectomy (OXV group) and dummy surgery (SHAM group). After 90 days, the ELISA test was performed and the ovariectomy effectiveness was confirmed. In each tibial metaphysis, an implant with PEO coating containing Ca²⁺ and P⁵⁺ molecules were installed, and the other tibia received an implant with SLA acid etching and blasting (AC) (control surface). After 42 days, 16 rats from each group were euthanized, their tibias were removed for histological and immunohistochemical analysis (OPG, RANKL, OC and TRAP), as well as reverse torque biomechanics. Data were submitted to One-way ANOVA or Kruskal-Wallis tests, followed by a Tukey post-test; P < 0.05. Histological analyses showed higher bone neoformation values among the members of the PEO group, SHAM and OVX groups. Immunohistochemical analysis demonstrated equilibrium in all groups when comparing surfaces for TRAP, OC and RANKL (P > 0.05), whereas OPG showed higher PEO labeling in the OVX group (P < 0.05). Biomechanical analysis showed higher reverse torque values (N.cm) for PEO, irrespective of whether they were OVX or SHAM groups (P < 0.05).

CONCLUSION

The results indicated that the PEO texturing method favored bone formation and showed higher bone maturation levels during later periods in osteoporotic rats.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria

Objective

The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects.

Material and Methods

A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in μCT were obtained to calculate bone mineral density (BMD).

Results

In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The μCT images showed filling defect by BCG (BMD= 1337 HU at 28 days).

Conclusion

Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.

Successful Use of Lower-Level Laser Therapy in the Treatment of Medication-Related Osteonecrosis of the Jaw

Case Presentation: This study aimed to report a case of medication related osteonecrosis of the jaw (MRONJ) of a 65-year-old female patient referred to the Oral and Maxillofacial Surgery team from Araçatuba Dental School, complaining about mobility of a previously dental implant placed on the posterior maxillary region. Clinical examination revealed an extensive necrosis area around the implant region. The patient reported bisphosphonate therapy with sodium alendronate for prevention of osteoporosis 5 years ago. A diagnosis of MRONJ was reached and the treatment decided was to remove the dental implant damaged and use the lower-level laser therapy (LLLT) associated with antibiotic therapy with clindamycin 300 mg and mouth rinses with chlorhexidine 0.12%. Conclusion: Six months after the treatment with LLLT a complete healing of the affected area was observed and 12 months after treatment the patient was rehabilitated with fixed dental prosthesis and showed excellent tissue healing of the necrosis areas. It was concluded that the use of LLLT showed to be a good option in the treatment of MRONJ.

Short term sodium alendronate administration improves the peri-implant bone quality in osteoporotic animals

Sodium alendronate is a bisphosphonate drug that exerts antiresorptive action and is used to treat osteoporosis.

Intraoperative blood loss and blood transfusion requirements in patients undergoing orthognathic surgery

Procedures for the surgical correction of dentofacial deformities may produce important complications, whether due to the potential for vascular injury or to prolonged surgery, both of which may lead to severe blood loss. Fluid replacement with crystalloid, colloid, or even blood products may be required. The aim of this study was to assess blood loss and transfusion requirements in 45 patients (18 males and 27 females; mean age 29.29 years, range 16-52 years) undergoing orthognathic surgery, assigned to one of two groups according to procedure type-rapid maxillary expansion or double-jaw orthognathic surgery. Preoperative hemoglobin and hematocrit levels and intraoperative blood loss were measured. There was a substantial individual variation in pre- and postoperative hemoglobin values (10.3-17 and 8.8-15.4 g/dL, respectively; p < 0.05). Mean hematocrit values were 41.53 % preoperatively (range 31.3-50.0 %) and 36.56 % postoperatively (range 25-43.8 %) (p < 0.05). Mean blood loss was 274.60 mL (range 45-855 mL). Only two patients required blood transfusion. Although blood loss and transfusion requirements were minimal in the present study, surgical teams should monitor the duration of surgery and follow meticulous protocols to minimize the risks.