Effect of different low-level intensity laser therapy (LLLT) irradiation protocols on the osseointegration of implants placed in grafted areas.

OBJECTIVE: To evaluate the effect of different protocols of low-level intensity laser therapy (LLLT) irradiation on the osseointegration of implants placed in grafted areas. METHODOLOGY: 84 rats were randomly allocated into six groups: DBB: defect filled with deproteinized bovine bone; HA/TCP: defect filled with biphasic ceramic of hydroxyapatite/ß-tricalcium phosphate ; DBB-LI: defect filled with DBB and treated with LLLT after implant placement; HA/TCP-LI: defect filled with HA/TCP and treated with LLLT after implant placement; DBB-LIB: defect filled with DBB and treated with LLLT after graft procedure and implant placement; and HA/TCP-LIB: defect filled HA/TCP and treated with LLLT after graft procedure and implant placement. The bone defects were made in the tibia and they were grafted. After 60 days, the implants were placed. The rats were subsequently subjected to euthanasia 15 and 45 days after implant placement. The pattern of osseointegration and bone repair in the grafted area was evaluated by biomechanical, microtomographic, and histometric analyses. Furthermore, the expression of bone biomarker proteins was assessed. RESULTS: The LLLT groups presented higher removal torque, mineralized tissue volume, and a greater degree of osseointegration, especially when LLLT was performed only after implant placement, and these findings were associated with higher expression of BMP2 and alkaline phosphatase. CONCLUSION: LLLT performed on implants placed in grafted areas enhances the osseointegration process.

Low-level laser therapy (LLLT) in sites grafted with osteoconductive bone substitutes improves osseointegration.

The aim of this study was to evaluate the osseointegration of implants placed in areas grafted with different osteoconductive bone substitutes irradiated with infrared low-level laser therapy (LLLT). Fifty-six rats were randomly allocated into 4 groups: DBB, bone defects filled with deproteinized bovine bone graft (DBB); HA/TCP, bone defects filled with biphasic ceramic made of hydroxyapatite and ß-tricalcium phosphate (HA/TCP); DBB-L, bone defects filled with DBB and treated by LLLT; HA/TCP-L, bone defects filled with HA/TCP and treated by LLLT. Bone defects were performed in the tibia of each animal and filled with the different biomaterials. The grafted areas were treated with LLLT (λ 808 nm, 100 mW, ϕ ∼ 0.60 mm) in 7 sessions with 48 h between the irradiations. After the 60-day period, the implants were placed, and the animals were euthanized after 15 and 45 days. The osseointegration and bone repair in the grafted area were evaluated by biomechanical, microtomographic and histometric analyses, and the expression of some bone biomarkers was evaluated by immunohistochemistry analysis. LLLT induced higher degree of osseointegration, which was associated with the greater expression of BMP2 and OCN. LLLT performed in areas grafted with osteoconductive bone substitutes prior to implant placement improves osseointegration.

Effect of avocado/soybean unsaponifiables on periodontal repair in rats with arthritis and induced periodontitis.

OBJECTIVE: This study aimed to evaluate the effect of avocado/soybean unsaponifiables (ASU) on periodontal repair in rats with induced periodontitis and arthritis. METHODOLOGY: Forty-five rats were submitted to periodontitis induction by insertion of ligatures into the upper second molars, maintained for 15 days. These animals were randomly allocated to 3 groups according to the presence of induced arthritis (ART) and the application of the ASU: Control (CTR) group-healthy animals, where saline solution was administered; ART-animals with induced arthritis, where saline solution was administered; ART/ASU-animals with induced arthritis, where ASU (0.6 mg/ kg) was administered. The drugs were administered daily by gavage and the animals were euthanized after 7, 15 and 30 days of the ligature removal. Bone resorption, inflammatory infiltrate composition and marker proteins expression of the differentiation and formation of osteoclasts (RANKL and TRAP) were assessed. RESULTS: The ART/ASU group presented higher bone volume than the ART group at 7 and 30 days after the ligature removal. Furthermore, the ART group presented higher quantity of inflammatory cells and expression of TRAP and RANKL than the other groups. CONCLUSION: ASU administration improves the repair of periodontal tissues in an experimental periodontitis model in rats with induced arthritis.

Impact of Soft Tissue Grafts to Reduce Peri-implant Alterations After Immediate Implant Placement and Provisionalization in Compromised Sockets.

This study evaluated the impact of soft tissue grafts to reduce marginal peri-implant recession (MPR) after 1 year of follow-up. A total of 24 patients with one single failing maxillary incisor presenting facial bone dehiscence and receiving an immediate implant, bone graft, and provisional were randomly divided into three groups (n = 8 in each group): control (CTL), collagen matrix (CM), and connective tissue graft (CTG). Clinical, photographic, and tomographic analyses were performed to evaluate tissue alterations. The use of a CTG avoided MPR (P < .05) and provided better contour of the alveolar ridge (P < .01) and greater thickness (P < .05) of the soft tissue at the implant facial aspect.

Effect of avocado/soybean unsaponifiables on osseointegration: a proof-of-principle preclinical in vivo study.

PURPOSE: To evaluate the influence of administration of avocado/soybean unsaponifiables (ASU) on implant osseointegration in rat tibiae. MATERIALS AND METHODS: Thirty rats were randomly assigned into one of three equal-sized groups: (1) ASU1: administration of ASU starting 7 days prior to implant placement; (2) ASU2: administration of ASU starting on the day of implant placement, and (3) CTL: administration of saline solution. In all animals, one titanium implant was placed in each tibia. All animals received ASU or saline solution by gavage daily until sacrifice 60 days postoperatively. Implant osseointegration and bone maturation were assessed by biomechanical and radiographic bone density analysis; descriptive histology; immunohistochemistry for bone morphogenetic protein 2 (BMP-2), transforming growth factor beta 1 (TGF-ß1), and osteocalcin; and histomorphometric evaluation of bone-to-implant contact (BIC) and mineralized bone area fraction within the threads of the implant. RESULTS: ASU1 and ASU2 showed three times higher expression of BMP-2 and nine times higher expression of TGF-ß1 compared with CTL (P < .05). Histomorphometric analysis, however, showed that both ASU1 and ASU2 groups presented significantly higher BIC values only in the cortical bone compartment when compared to CTL (P < .05). CONCLUSION: ASU consumption seems to exert only a subtle effect on implant osseointegration.

Effects of low-level laser therapy (685 nm) at different doses in osteogenic cell cultures.

The present in vitro study evaluated parameters of osteogenesis under the influence of low-level laser therapy (LLLT) at different doses. Osteogenic cells originated from rat calvaria were cultivated in polystyrene plates and exposed to a laser irradiation using an indium-gallium-aluminum phosphide therapeutic laser (InGaAIP), at wavelength of 685 nm, power of 35 mW, 600-µm-diameter optical fiber, and continuous wave. In the attempt of observing the existence of a dose response and its effects, laser irradiation was performed at 25, 77, and 130 J/cm(2) (7, 22, and 37 s, respectively). The following parameters were assessed: growth curve (4, 7, and 11 days), cell viability (24 h), and nodular formation of mineralized matrix (14 days). The results did not show significant differences related to the growth curve (4, 7, and 11 days) and cell viability (24 h). Within 14 days, osteogenic cultures showed nodular areas with well-defined calcified matrix. The total area stained with Alizarin Red did not show any differences between doses of 25 and 130 J/cm(2). However, the percentage of stained area was significantly higher in the 25 J/cm(2) group when compared to the group of 77 J/cm(2) (Kruskal-Wallis test, p < 0.05). It was possible to conclude that the 685-nm laser irradiation (at 25, 77, and 130 J/cm(2)) did not influence cell growth and proliferation, although the extracellular mineralization process may have its pattern altered by the LLLT on osteogenic cell cultures.

Homeopathic Symphytum officinale increases removal torque and radiographic bone density around titanium implants in rats.

INTRODUCTION: This study evaluated the effect of Symphytum officinale in homeopathic potency (6cH), on the removal torque and radiographic bone density around titanium implants, inserted in rats tibiae. METHODS: Implants were placed in male rat tibiae, and the animals randomized to two groups (Control and S. officinale 6cH treated), which were evaluated at 7, 14, 28 and 56 days post-implantation. Radiographic bone density was measured at 6 points around the implant, using digital radiographic images, when implants were inserted and at sacrifice. Removal torque of the implants was also evaluated. RESULTS: Both removal torque and radiographic bone density evaluation showed that S. officinale 6cH treatment enhanced bone formation around the micro-implants, mainly at 14 days. At 56 days, the radiographic bone density was higher in the treated group. CONCLUSIONS: We conclude that S. officinale 6cH enhances, principally at the early stages of osseointegration, bone formation around titanium implants in rats' tibiae, based on radiographic and mechanical analysis.

Influence of homeopathic treatment with comfrey on bone density around titanium implants: a digital subtraction radiography study in rats.

OBJECTIVE: The objective of this study was to evaluate the influence of homeopathic treatment with comfrey (Shymphytum officinalis 6CH) on radiographic bone density and area around titanium implants. MATERIAL AND METHODS: Forty-eight rats were divided into two groups of 24 animals each: a control group (C) and a test group (SO). Each animal received one titanium micro-implant placed in the tibia. The animals in Group SO were subjected to 10 drops of comfrey 6CH per day mixed into their drinking water until the day of sacrifice. Eight animals of each group were sacrificed at 7, 14 and 28 days post-surgery, respectively. Standardized digital radiographs were obtained on the day of implant installation (baseline images) and on the day of sacrifice (final images). Digital subtraction of the two corresponding images was performed to evaluate changes in bone density and the area related to change around the implant between baseline and final images. RESULTS: Subtraction images demonstrated that a significant difference existed in mean shade of gray at 14 days post-surgery between Group SO (mean 175.3+/-14.4) and Group C (mean 146.2+/-5.2). Regarding the area in pixels corresponding to the bone gain in Group SO, the differences observed between the sacrifice periods and groups were only significant at 7 days sacrifice between Group SO (mean 171.2+/-21.9) and Group C (mean 64.5+/-60.4). CONCLUSION: Within the limits of this study, comfrey administration promotes an increase in radiographic bone density around titanium implants in the initial period of bone healing.