A biocomplex to repair experimental critical size defects associated with photobiomodulation therapy

The association of scaffolds to repair extensive bone defects can contribute to their evolution and morphophysiological recomposition. The incorporation of particulate biomaterials into three-dimensional fibrin bioproducts together with photobiomodulation therapy (PBM) has potential and can improve regenerative medicine procedures. The objective of this experiment was to evaluate the effects of PBM therapy on critical size defects filled with xenogenic bone substitute associated with fibrin biopolymer. Methods: A critical defect of 8 mm was performed in 36 Wistar male adult rats that were divided into four groups. Groups BC and BC-PBM were defined as controls with defects filled by a clot (without or with PBM, respectively) and groups XS and XS-PBM that comprised those filled with biocomplex Bio-OssTM in association with fibrin biopolymer. PBM was applied immediately after the surgery and three times a week every other day, with the parameters: wavelength of 830 nm, energy density 6.2 J/cm2, output power 30 mW, beam area of 0.116 cm2, irradiance 0.258,62 W/cm2, energy/point 0.72 J, total energy 2.88 J. Fourteen and 42 days after the surgery, animals were euthanatized and subjected to microtomography, qualitative and quantitative histological analysis. Results: The BC-PBM and XS-PBM groups had a similar evolution in the tissue repair process, with a higher density of the volume of new formed bone in relation to the groups without PBM (p = 0.04086; p = 0.07093, respectively). Intense vascular proliferation and bone deposition around the biomaterial particles were observed in the animals of the groups in which biocomplex was applied (XS and XS-PBM). Conclusion: PBM therapy allowed an improvement in the formation of new bone, with a more organized deposition of collagen fibers in the defect area. Biocomplex favored the insertion and permanence of the particulate material in bone defects, creating a favorable microenvironment for accelerate repair process.(AU)

Procedimentos regenerativos endodônticos com clorexidina a 2% e hidróxido de cálcio: relato de caso / Endodontic regenerative procedures with 2% chlorhexidine and calcium hydroxide: case report

Introdução: Muitas substâncias têm sido utilizadas como irrigantes e curativos intracanal nos tratamentos de dentes com rizogênese incompleta, visando obter a regeneração pulpar. A clorexidina a 2% em associação com hidróxido de cálcio P.A. pode ser uma alternativa. Métodos: No presente caso clínico, o dente #45 com periodontite apical, em um paciente com 13 anos de idade, foi tratado com solução de clorexidina a 2% como irrigante. A clorexidina na forma de gel a 2% foi utilizada como auxiliar da instrumentação e, em associação com o hidróxido de cálcio, foi utilizada como curativo durante 14 dias. Após esse período, o canal foi irrigado com solução fisiológica e, sob anestesia alveolar mandibular, uma lima K #70 foi utilizada ultrapassando levemente o ápice, para causar sangramento. Após observar que o sangue dentro dos canais alcançou a porção cervical, o cimento biocerâmico MTA Branco foi colocado na porção cervical do canal. Resultados: A apicificação e o desenvolvimento da raiz em comprimento e largura puderam ser observados já no controle de três meses, e continuaram até a última revisão, no controle de um ano. Alterações de cor não foram observadas nese período de acompanhamento. Conclusões: A clorexidina associada ao hidróxido de cálcio pode ser uma alternativa aos procedimentos de regeneração pulpar (AU).

Introduction: Many substances have been used as irrigating solutions to promote pulp regeneration and root development in teeth with incomplete rhizogenesis. The use of 2% chlorhexidine as an irrigating solution in association with Calcium Hydroxide could be an alternative. Methods: In the case of the patient, a 13-year-old boy, here presented, tooth 45 with apical periodontitis was treated with 2% Chlorhexidine solution as irrigant adjuvant to instrumentation, in association with Calcium Hydroxide used as a dressing for 14 days. After this period, the canal was cleaned with a physiological solution and under mandibular alveolar anesthesia, a # 70 K file was used slightly over the apex to cause bleeding. After observing that blood inside the canals had reached the cervical portion. White MTA was placed in the cervical portion of the canal. Results: Induced apexification and development of increasing root length and width could already be observed in the three-month control exam, and this continued until the last review in the one-year control exam. No color changes were observed in this follow-up period. Conclusions: Chlorhexidine and calcium hydroxide could be used as an alternative to pulp regeneration procedures (AU).

Photobiomodulation Therapy on the Guided Bone Regeneration Process in Defects Filled by Biphasic Calcium Phosphate Associated with Fibrin Biopolymer.

The aim is to evaluate the effects of photobiomodulation therapy (PBMT) on the guided bone regeneration process (GBR) in defects in the calvaria of rats filled with biphasic calcium phosphate associated with fibrin biopolymer. Thirty male Wistar rats were randomly separated: BMG (n = 10), defects filled with biomaterial and covered by membrane; BFMG (n = 10), biomaterial and fibrin biopolymer covered by membrane; and BFMLG (n = 10), biomaterial and fibrin biopolymer covered by membrane and biostimulated with PBMT. The animals were euthanized at 14 and 42 days postoperatively. Microtomographically, in 42 days, there was more evident bone growth in the BFMLG, limited to the margins of the defect with permanence of the particles. Histomorphologically, an inflammatory infiltrate was observed, which regressed with the formation of mineralized bone tissue. In the quantification of bone tissue, all groups had a progressive increase in new bone tissue with a significant difference in which the BFMLG showed greater bone formation in both periods (10.12 ± 0.67 and 13.85 ± 0.54), followed by BFMG (7.35 ± 0.66 and 9.41 ± 0.84) and BMG (4.51 ± 0.44 and 7.11 ± 0.44). Picrosirius-red staining showed greater birefringence of collagen fibers in yellow-green color in the BFMLG, showing more advanced bone maturation. PBMT showed positive effects capable of improving and accelerating the guided bone regeneration process when associated with biphasic calcium phosphate and fibrin biopolymer.

Photobiomodulation Therapy Associated with Heterologous Fibrin Biopolymer and Bovine Bone Matrix Helps to Reconstruct Long Bones.

Bone defects cause aesthetic and functional changes that affect the social, economic and especially the emotional life of human beings. This complication stimulates the scientific community to investigate strategies aimed at improving bone reconstruction processes using complementary therapies. Photobiomodulation therapy (PBMT) and the use of new biomaterials, including heterologous fibrin biopolymer (HFB), are included in this challenge. The objective of the present study was to evaluate the influence of photobiomodulation therapy on bone tibial reconstruction of rats with biomaterial consisting of lyophilized bovine bone matrix (BM) associated or not with heterologous fibrin biopolymer. Thirty male rats were randomly separated into three groups of 10 animals. In all animals, after the anesthetic procedure, a noncritical tibial defect of 2 mm was performed. The groups received the following treatments: Group 1: BM + PBMT, Group 2: BM + HFB and Group 3: BM + HFB + PBMT. The animals from Groups 1 and 3 were submitted to PBMT in the immediate postoperative period and every 48 h until the day of euthanasia that occurred at 14 and 42 days. Analyses by computed microtomography (µCT) and histomorphometry showed statistical difference in the percentage of bone formation between Groups 3 (BM + HB + PBMT) and 2 (BM + HFB) (26.4% ± 1.03% and 20.0% ± 1.87%, respectively) at 14 days and at 42 days (38.2% ± 1.59% and 31.6% ± 1.33%, respectively), and at 42 days there was presence of bone with mature characteristics and organized connective tissue. The µCT demonstrated BM particles filling the defect and the deposition of new bone in the superficial region, especially in the ruptured cortical. It was concluded that the association of PBMT with HFB and BM has the potential to assist in the process of reconstructing bone defects in the tibia of rats.

Fibrin Sealant Derived from Human Plasma as a Scaffold for Bone Grafts Associated with Photobiomodulation Therapy.

Fibrin sealants derived from human blood can be used in tissue engineering to assist in the repair of bone defects. The objective of this study was to evaluate the support system formed by a xenograft fibrin sealant associated with photobiomodulation therapy of critical defects in rat calvaria. Thirty-six rats were divided into four groups: BC (n = 8), defect filled with blood clot; FSB (n = 10), filled with fibrin sealant and xenograft; BCPBMT (n = 8), blood clot and photobiomodulation; FSBPBMT (n = 10), fibrin sealant, xenograft, and photobiomodulation. The animals were killed after 14 and 42 days. In the histological and microtomographic analysis, new bone formation was observed in all groups, limited to the defect margins, and without complete wound closure. In the FSB group, bone formation increased between periods (4.3 ± 0.46 to 6.01 ± 0.32), yet with lower volume density when compared to the FSBPBMT (5.6 ± 0.45 to 10.64 ± 0.97) group. It was concluded that the support system formed by the xenograft fibrin sealant associated with the photobiomodulation therapy protocol had a positive effect on the bone repair process.