Synthetic Parathyroid Hormone May Augment Bone Volume in Autogenous Grafts: A Study in Rats.

BACKGROUND: Synthetic parathyroid hormone [PTH(1-34)] has been investigated for its benefits on bone healing and osteoporosis treatment; however, there is little information regarding bone grafts. This study therefore investigates the effect of PTH(1-34) on autogenous bone graft healing. METHODS: Bone grafts were harvested from the calvarium of rats with a trephine bur (3-mm internal diameter) and placed on the cortex near the mandible angle with a titanium screw. Animals were randomly assigned to group 1 (control): subcutaneous injections of saline solution, three times a week (n = 15); group 2: 2 µg/kg PTH(1-34), three times a week (n = 15); and group 3: 40 µg/kg PTH(1-34), three times a week (n = 15). Thirty days postoperatively, the animals were killed, and specimens (implant + bed + graft) were removed and used for undecalcified sections. The following histometric parameters were evaluated: total bone thickness (TT) (bed + gap + graft), graft thickness (GT) (adjacent to the implant), bone-to-implant contact (BIC), and bone area (BA) (within the limits of the threads). Five additional animals were sacrificed immediately after surgery (zero hour) to register bed and graft sizes before healing. RESULTS: Group 3 showed significantly greater bone gain compared with groups 1 and 2 (TT and GT, P <0.05). In relation to initial thickness (zero hour), groups 1 and 2 showed a total decrease in volume of 15.91% and 20.83%, respectively, whereas group 3 showed a slight bone gain (1.21%). Data analysis revealed a significant difference for group 3 compared with groups 1 and 2 (P <0.01). No differences were observed for BIC and BA (P >0.05). CONCLUSION: Systemic administration of PTH(1-34) augmented bone volume in autogenous grafts.

Two-year randomized clinical trial of enamel matrix derivative treated infrabony defects: radiographic analysis.

BACKGROUND: This split-mouth, double-blind randomized controlled trial evaluated radiographic changes in infrabony defects treated with open flap debridement (OFD) or OFD associated with enamel matrix derivative (EMD) after a 24-month follow-up. The radiographic distance from the CEJ to the bottom of the defect (BD) was considered the primary outcome. CEJ-BC and defect angle were secondary outcomes. METHODS: Ten patients presenting 2 or more defects were selected. An individualized film holder was used to take standardized radiographs of the 43 defects, at baseline and after 24 months. Images were digitized and used to measure the distances from the cemento-enamel junction (CEJ) to the alveolar crest (AC), CEJ to the bottom of the defect (BD) and infrabony defect angle. Statistical analysis was performed in SPSS for Windows (version 5.2). Paired samples t test was used to compare test and control groups and to evaluate changes within each group. The level of significance was set at α = 0.05%. RESULTS: After 24 months, a significant crestal bone loss was observed for EMD (1.01 mm; p = 0.049) but not for OFD (0.14 mm; p = 0.622). However, no differences were detected between groups (p = 0.37). Reduction of the bone defect depth was significant for OFD (0.70 mm; p = 0.005) but not for EMD (0.04 mm; p = 0.86), while no differences were detected between them (p = 0.87). Both EMD (0.69°; p = 0.82) and OFD (5.71°; p = 0.24) showed an improvement in defect angle measurements but no significant differences were observed after 24 months or between the groups (p = 0.35). CONCLUSION: Linear radiographic analysis was not able to demonstrate superiority of EMD treated infrabony defects when compared to ODF after 24 months. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02195765. Registered 17 July 2014.

Immunolocalization of bone morphogenetic protein 2 during the early healing events after guided bone regeneration.

OBJECTIVE: The objective of this study was to evaluate the immunolocalization of bone morphogenetic protein 2 (BMP-2) after autogenous block grafting covered or not with an e-PTFE membrane. STUDY DESIGN: Forty-eight rats were divided into 2 groups, autogenous block graft (B) and autogenous block graft + e-PTFE membrane (MB), and were evaluated by immunohistochemistry at baseline and 3, 7, 14, 21, and 45 days. RESULTS: The largest number of positive cells in the recipient bed was observed after 3 days in both groups. At the graft border, the largest number of positive cells was seen after 7 days in group B and after 14 days in group MB. The highest proportion of staining in the graft was observed after 3 days in group B and after 21 days in group MB. CONCLUSIONS: High proportions of stain were related to intense revascularization and osteogenesis. Except for the interface, BMP-2 staining occurred later in group MB than in group B in all structures analyzed.

Subgingival ultrasonic instrumentation of residual pockets irrigated with essential oils: a randomized controlled trial.

AIM: To evaluate the clinical efficacy of subgingival ultrasonic instrumentation irrigated with essential oils (EOs) of residual periodontal pockets. MATERIAL AND METHODS: Sixty-four individuals with chronic periodontitis were invited to participate in this randomized, double-blind, parallel, and placebo-controlled clinical trial. All subjects received non-surgical periodontal therapy. After re-evaluation (baseline), residual pockets (pocket depth ≥5 mm) received test (ultrasonic instrumentation irrigated with EOs) or control therapy (ultrasonic instrumentation irrigated with negative control). Probing pocket depth (PPD), gingival recession (R), clinical attachment level (CAL), bleeding on probing (BOP), and plaque were assessed at baseline and after 4, 12, and 24 weeks. Differences between groups and changes over the course of time were analysed according to a generalized linear model. RESULTS: There was a significant reduction in PPD and BOP, as well as a significant CAL gain in the two groups (p<0.001). Nevertheless, there were no differences between the groups at any time of the study. When only initially deep pockets (PPD ≥7 mm) were analysed, a significantly greater CAL gain (p=0.03) and PPD reduction (p=0.01) was observed in the test group. CONCLUSION: The adjunctive use of EOs may promote significant CAL gain and PPD reduction in deep residual pockets.

Influence of osteopenia in autogenous bone graft healing with or without expanded polytetrafluoroethylene membranes: histologic and histomorphometric study in rats.

PURPOSE: The aim of this study was to quantitatively evaluate and qualitatively describe autogenous bone graft healing with or without an expanded polytetrafluoroethylene (e-PTFE) membrane in ovariectomized rats. MATERIALS AND METHODS: Eighty Wistar rats, weighing approximately 300 g each, were used. A graft was obtained from the parietal bone and fixed to the sidewall of each animal's left mandibular ramus. The animals were randomly divided into four experimental groups (n = 20 in each group): group 1, sham operated and autogenous bone graft only; group 2, sham operated and autogenous bone graft covered by e-PTFE membrane; group 3, ovariectomized (OVX) and autogenous bone graft only; group 4, OVX and autogenous bone graft covered by e-PTFE membrane. The animals were sacrificed at five different time points: immediately after grafting or at 7, 21, 45, or 60 days after grafting. Histologic examination and morphometric measurement of the sections were performed, and values were submitted to statistical analyses. RESULTS: Both groups (sham and OVX) experienced loss of the original graft volume when it was not covered by the membrane, whereas use of the membrane resulted in additional bone formation beyond the edges of the graft and under the membrane. Histologic analysis showed integration of the grafts in all animals, although a larger number of marrow spaces was found in OVX groups. CONCLUSIONS: Association of bone graft with an e-PTFE membrane resulted in maintenance of its original volume as well as formation of new bone that filled the space under the membrane. Osteopenia did not influence bone graft repair, regardless of whether or not it was associated with e-PTFE membrane, but descriptive histologic analysis showed larger numbers of marrow spaces in the bone graft and receptor bed and formation of new bone in the OVX animals.

Characterization of bone cells obtained from the calvaria of neonatal rats (osteo-1) after serial subculture.

The objective of the present study was to characterize bone cells grown in two culture media, and to determine the effective concentration of OP-1 on the growth of osteo-1 cells. Subcultured rat bone cells (osteo-1) were grown in alpha-modified Eagle's minimal essential medium (alpha-MEM) and Dulbecco's modified Eagle's medium (DMEM) and total protein content, alkaline phosphatase activity and the formation of mineralized nodules were evaluated after 7, 14 and 21 days. Cells were exposed to different concentrations of rhOP-1 for 1, 3, 5 and 7 days and compared with an untreated control. Osteo-1 cells presented a significant increase in alkaline phosphatase activity and calcium deposits were observed at 21 days. Cells treated with 10 and 20 ng/mL rhOP-1 for 24 h showed a significant increase in cell viability when compared to control. Osteo-1 cells cultured on DMEM demonstrated an osteoblastic phenotype as indicated by high alkaline phosphatase activity and the presence of calcified nodules. The results suggest that low concentrations of OP-1 may promote an osteogenic effect on osteo-1 cells.

Repair of Class II furcation defects after a reparative tissue graft obtained from extraction sockets treated with growth factors: a histologic and histometric study in dogs.

BACKGROUND: Reparative tissue of extraction sockets was proposed as grafting material in the treatment of periodontal defects. Our hypothesis was that the addition of growth factors to extraction sockets improves the regenerative potential of this tissue when used as a graft. The objective of the present study was to analyze qualitatively and quantitatively the repair of acute Class II furcation defects after they receive this grafting material. METHODS: The second and third upper premolars were extracted from four dogs. Platelet-derived growth factor (PDGF)-BB and insulin-like growth factor (IGF)-I, at concentrations of 6 microg/ml each, were applied to the resulting sockets. After 5 days, 24 acute defects (12 control and 12 test defects) were created in the second, third, and fourth lower premolars. Only the test sites received the graft. The flaps were positioned coronally on both sides and sutured. After 45 days, the specimens were collected, decalcified, and processed histologically in a buccal-lingual plane. The parameters were measured horizontally in the buccal-lingual direction. RESULTS: Repair was histologically and histometrically similar in the two groups. No significant difference was observed between the test and control groups in the parameters connective tissue, new cementum, new bone, and junctional epithelium. CONCLUSION: The use of this graft did not show beneficial effects on the repair of acute Class II furcation defects in dogs.

Propolis extract as an adjuvant to periodontal treatment.

PURPOSE: The aim of this study was to evaluate the effect of subgingival irrigation with propolis extract by clinical and microbiological parameters. MATERIALS AND METHODS: Twenty patients diagnosed with chronic periodontitis presenting three non-adjacent teeth with deep pockets were selected. After scaling and root planing, the selected periodontal sites were submitted to one of the following treatments: irrigation with a hydro alcoholic solution of propolis extract twice/week for two weeks (group A); irrigation with a placebo twice/week for two weeks (group B); or no additional treatment (C). Subgingival plaque sampling and scaling and root planing were performed two weeks after clinical data recording. Two weeks later irrigation procedures were started (Baseline). Microbiological and clinical data were collected at baseline, and after 4, 6 and 24 weeks. RESULTS: A decrease in total viable counts of anaerobic bacteria (p=0.007), an increase in the proportion of sites with low levels (< or = 10(3) cfu/mL) of Porphyromonas gingivalis (p=0.005), and a decrease in the number of sites with detectable presence of yeasts (p=0.000) were observed in group A sites when compared to group B and C sites. Propolis treatment did not lead to an increase in organisms such as coagulase positive Staphylococci and Pseudomonas spp. 24 weeks after treatment there was an increased proportion of sites showing probing depth (PD) < or = 3 mm in Group A sites. CONCLUSION: Subgingival irrigation with propolis extract as an adjuvant to periodontal treatment was more effective than conventional treatment both by clinical and microbiological parameters.