Ozone therapy improves early stages of osseointegration in ovariectomized rats

OBJECTIVE

the aim of this study was to analyze the influence of ozone therapy (OZN) on peri-implant bone repair in critical bones by installing osseointegrated implants in the tibia of ovariectomized rats.

METHODOLOGY

ovariectomy was performed on 30 Wistar rats, aged six months (Rattus novergicus), and, after 90 days, osseointegrated implants were installed in each tibial metaphysis. The study groups were divided into the animals that received intraperitoneal ozone at a concentration of 700 mcg/kg - OZ Group (n=15) - and a control group that received an intraperitoneal saline solution and, for this reason, was named the SAL group (n=15). The applications for both groups occurred during the immediate post-operative period on the 2nd, 4th, 6th, 8th, 10th, and 12th day post-surgery. At various stages (14, 42, and 60 days), the animals were euthanized, and tests were performed on their tibiae. These tests include histomorphometric and immunohistochemical analyses, computerized microtomography, sampling in light-cured resin for calcified sections, and confocal microscopy. The obtained data were then analyzed using One-way ANOVA and the Shapiro-Wilk, Kruskal-Wallis, and student t-tests (P<0.05).

RESULTS

our findings indicate that the OZ group (3.26±0.20 mm) showed better cellular organization and bone neoformation at 14 days (SAL group, 0.90±1.42 mm) (P=0.001). Immunohistochemistry revealed that osteocalcin labeling was moderate in the OZ group and mild in the SAL group at 14 and 42 days post-surgery. The data from the analysis of calcified tissues (microtomography, histometric, and bone dynamism analysis) at 60 days showed no statistically significant differences between the groups (P=0.32).

CONCLUSION

it was concluded that ozone therapy anticipated the initial phases of the peri-implant bone repair process.

Polydioxanone Enhances Bone Regeneration After Resection and Reconstruction of Rat Femur with rhBMP2

The aim of this study was to assess the bone regeneration potential of a polydioxanone (PDO) scaffold together with recombinant human bone morphogenetic protein-2 (rhBMP-2) for the reconstruction of large bone defect. In total, 24 male rats (6 months old) were subjected to bilateral femoral stabilization using titanium plates to create a 2 mm gap, and reconstruction using rhBMP-2 (Infuse®; 3.25 μg). The bone defects were covered with PDO (PDO group), or with titanium mesh (Ti group). Animals were euthanized on days 14 and 60. Simultaneously, 16 rats received PDO and Ti in their dorsum for the purpose of biocompatibility analysis at 3, 5, 7, and 10 days postoperatively. X-ray densitometry showed a higher density in the PDO group on day 14. On day 60, coverage of the bone defect with PDO showed a larger quantity of newly formed bone than that found for the Ti group, a lower inflammatory infiltrate value, and a more significant number of blood vessels on day 14. By immunohistochemical assessment, runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) showed higher labeling on day 14 in the PDO group. On day 60, bone morphogenetic protein-2 (BMP-2) showed higher labeling in the PDO group, whereas Ti showed higher labeling for osteoprotegerin, nuclear factor kappa B ligand-activating receptor, RUNX2, and OCN. Furthermore, biocompatibility analysis showed a higher inflammatory response in the Ti group. The PDO scaffold enhanced bone regeneration when associated with rhBMP-2 in rat femur reconstruction. Impact statement Regeneration of segmental bone defects is a difficult task, and several techniques and materials have been used. Recent advances in the production of synthetic polymers, such as polydioxanone (PDO), produced by three-dimensional printing, have shown distinct characteristics that could improve tissue regeneration even in an important bone defect. The present preclinical study showed that PDO membranes used as scaffolds to carry recombinant human bone morphogenetic protein-2 (rhBMP-2) improved bone tissue regeneration by more than 8-fold when compared with titanium mesh, suggesting that PDO membranes could be a feasible and useful material for use in guided bone regeneration. (In English, viable is only used for living creatures capable of sustaining life.

What are the Consequences of Incorrect Handling in the Treatment of Blunt-Cut Lip Injuries?

This study aimed report two cases of blunt-cut lip injury which occurred in postoperatory dehiscence. Patients were referred to the emergence attendance and the clinical examination revealed extensive laceration on the upper and lower lips of both patients, highly contaminated with asphalt residue. The affected regions were properly cleaned with saline and antiseptic solution, and, under local anesthesia, suturing was performed in layers in the muscle and oral mucosa region with 4-0 resorbable thread and in the skin region with 6-0 non-absorbable thread. Patients presented different levels of dehiscence on post-operatory evaluation. Thus, it was prescribed antibiotic and healing ointments for decontamination and improvement of the healing process. Third days post-operatory one of the patients presented a great healing of external lips and vermilion lip. However, the other patient presented aesthetic sequelae in the vermilion region of the lip, with a line of fibrosis and misalignment in the region, but not function sequelae. Thus, it was concluded that blunt injuries on the lip must strictly follow the established treatment protocols and must begin aiming for favorable results in the first intervention. Moreover, the postoperative care of the patient and the surgeon are as important as the procedure itself.

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.

Simultaneous Occurrence of Central Giant Cell Granuloma and Odontogenic Keratocyst in Mandible

Odontogenic keratocysts and central giant cell granulomas are distinct entities of separate origin that may appear simultaneously in the jaw, making them difficult to differentiate. The objectives of this paper are to report a case of a 54-year-old man presenting with a large lesion in the right mandible and to describe the histological characteristics of that lesion. Imaging revealed tumefaction and multilobulation. The case was surgically managed. Histopathological examination revealed that the lesion was a hybrid of an odontogenic keratocyst and a central giant cell granuloma. It remains unclear as to whether this lesion represented a coincidental or related injury. Since both types of lesion involved have a high rate of recurrence, however, long-term follow-up is scheduled.

Non-familial Cherubism – Report of a case

Introduction: The Cherubism is a rare disease that affects the middle and lower third of the face in individuals at the time of childhood. It is a rare hereditary benign bone disease with an autosomal dominant inheritance. The familial distribution may affect different generations and isolated non-familial cases have also been reported in literature. Lesions appear as cystic multilocular radiolucencies, histologically, resembles central giant cell granluloma and hyperparathyroidism brown tumor with numerous randomly distributed multinucleated giant cells and vascular spaces within a fibrous connective tissue stroma. Objectives: The aim of this study is to report the importance of the diagnosis of this pathology and the variety of treatments available in the literature, thus guiding to an individualized treatment. Case Report: Caucasian 8 years-old female, in good general condition, was referred to Service of Oral and Maxillofacial Surgery of Erasto Gaertner Hospital (EGH), Curitiba – PR, Brazil, complaining of bilateral swelling of the maxilla and mandible since 4 years-old. Apparently, the girl is the first one who developed the genetic pathology in at least 4 generation of her family. After biopsy, cherubism diagnosis was confirmed and the treatment of choice was periodic monitoring. Discussion: Cherubism studies with long-term follow-up with clinical and radiographic documentation indicate that the spontaneous resolution of bone lesions is rare. Treatment of cherubism is controversial and various modalities have been reported as the use of calcitonin, osseous plasty surgery, curettage, orthognathic surgery, liposuction and palliative treatments.