Bifidobacterium animalis subspecies lactis HN019 can reduce the sequelae of experimental periodontitis in rats modulating intestinal parameters, expression of lipogenic genes, and levels of hepatic steatosis.

OBJECTIVE: To determine whether Bifidobacterium animalis subspecies lactis HN019 (B. lactis HN019) can reduce the sequelae of experimental periodontitis (EP) in rats modulating systemic parameters. BACKGROUND: This study evaluated the effects of probiotic therapy (PROB) in the prevention of local and systemic damage resulting from EP. METHODS: Forty-eight rats were allocated into four groups: C (control), PROB, EP, and EP-PROB. PROB (1 × 1010 CFU/mL) administration lasted 8 weeks and PE was induced on the 7th week by placing ligature on the animals' lower first molars. All animals were euthanized in the 9th week of the experiment. Biomolecular analyses, RT-PCR, and histomorphometric analyses were performed. The data obtained were analyzed statistically (ANOVA, Tukey, p < .05). RESULTS: The EP group had higher dyslipidemia when compared to the C group, as well as higher levels of insulin resistance, proteinuria levels, percentages of systolic blood pressure, percentage of fatty hepatocytes in the liver, and expression of adipokines was up-regulated (LEPR, NAMPT, and FABP4). All these parameters (except insulin resistance, systolic blood pressure, LEPR and FABP4 gene expression) were reduced in the EP-PROB group when compared to the EP group. The EP group had lower villus height and crypt depth, as well as a greater reduction in Bacteroidetes and a greater increase in Firmicutes when compared to the EP-PROB group. Greater alveolar bone loss was observed in the EP group when compared to the EP-PROB group. CONCLUSION: Bifidobacterium lactis HN019 can reduce the sequelae of EP in rats modulating intestinal parameters, attenuating expression of lipogenic genes and hepatic steatosis.

Adjuvant use of multispecies probiotic in the treatment of peri-implant mucositis: A randomized controlled trial.

AIM: This randomized placebo-controlled clinical trial evaluated the effects of multispecies probiotic containing Lactobacillus rhamnosus HN001™, Lactobacillus paracasei Lpc-37®, and Bifidobacterium animalis subsp lactis HN019™ as an adjunct to mechanical debridement (MD) on changes in bleeding on probing (BOP) in edentulous patients with peri-implant mucositis (PiM). MATERIALS AND METHODS: Patients were randomly assigned to test (probiotic) or control (placebo) groups. All sites with PiM received MD and topical gel application (probiotic or placebo) at baseline and 12 weeks. After initial MD, patients consumed probiotic or placebo capsules twice a day for 12 weeks. Clinical (modified sulcus bleeding index [mSBI]; modified plaque index [mPI]; probing depth [PD]; and BOP) and immunological parameters were collected at baseline and after 12 and 24 weeks. Data were statistically analysed (p < .05). RESULTS: Thirty-six patients with PiM were recruited. The test group presented higher prevalence (p < .05) of cases of restored peri-implant health at 24 weeks than did the control group (72.2% and 33.3%, respectively). No significant difference was observed between test (n = 18) and control (n = 18) groups for mPI and PD. mSBI %-score 0 was higher in the test group than in the control group at 24 weeks (p < .05). When compared with baseline, both groups presented reduced BOP at 12 and 24 weeks (p < .05). BOP was lower in the test group than in the control group at 12 (mean difference = -14.54%; 95% confidence interval [CI] = -28.87 to 0.22; p = .0163) and 24 (mean difference = -12.56%; 95% CI = -26.51 to 1.37; p = .0090) weeks. At 24 weeks, only the test group presented lower levels of interleukin (IL)-1ß, IL-6, IL-8, and tumour necrosis factor (TNF)-α than those at baseline (p < .05). CONCLUSIONS: The multispecies probiotic (administered locally and systemically) containing L. rhamnosus HN001™, L. paracasei Lpc-37®, and B. lactis HN019™ as an adjunct to repeated MD promotes additional clinical and immunological benefits in the treatment of PiM in edentulous patients (ClinicalTrials.gov NCT04187222).

Effectiveness of Multistrain Versus Single-strain Probiotics: Current Status and Recommendations for the Future.

Probiotics are investigated as single-strain and multistrain products. In the market, however, there is an increasing tendency to work with multistrain probiotics, in particular, products with a high number of different strains. There are some thoughts behind this: more strains imply more chances of success; it can mean a broader spectrum of efficacy, and there is often the hope that there are at least additive and, potentially, even synergistic effects. The present review did not find convincing evidence that these assumptions are valid. There is, however, also no strong evidence that the assumptions are incorrect and/or that there is antagonistic activity between strains in a combination. We suggest that, to answer these questions, structured research is conducted. Starting with a systematic review of meta-analyses that have compared single-strain and multistrain probiotic efficacy, dedicated human studies need to be performed, comparing single-strain and multistrain probiotics to each other and placebo. In vitro and animal studies can provide indications and may help understand mechanisms. For human, animal, and in vitro studies, it is recommended to work with the simple setup of 2 single strains, a 2-strain combination, and placebo. It is also important in such research to take into consideration the doses, as a combination product will have a higher total dose.

Effects of the prebiotic mannan oligosaccharide on the experimental periodontitis in rats.

AIM: To evaluate the effect of the prebiotic (PREB) mannan oligosaccharide (MOS) on the progression of the experimental periodontitis (EP) and intestinal morphology in rats. MATERIALS AND METHODS: Forty rats were randomly allocated into groups (n = 10): C (control), PREB, EP and EP-PREB. Groups PREB and EP-PREB received MOS incorporated into the feed daily. After 30 days, groups EP and EP-PREB received a cotton ligature around their mandibular first molars, kept for 14 days. Morphometrical, histomorphometrical, microcomputed tomography, gene expression analyses and immunohistochemistry were performed. Data were statistically analysed (p < 0.05). RESULTS: Group EP-PREB showed less interproximal bone loss, area without bone in the furcation and bone porosity, and greater bone mineral density than group EP (p < 0.05). It was also observed a significant decrease in IL-10 and IFN-γ gene expression, besides a decrease in TNF-α and IL-1ß and an increase in TGF-ß immunolabeling score for group EP-PREB. Group EP-PREB also presented villous height and crept depth values similar to group C, while group EP presented reduced values (p < 0.05). CONCLUSION: It can be concluded that the oral administration of MOS promotes a protective effect against alveolar bone loss caused by EP in rats, modifying histologic and immune-inflammatory parameters, in addition to protecting the intestine.

Effects of Bifidobacterium probiotic on the treatment of chronic periodontitis: A randomized clinical trial.

AIM: This randomized placebo-controlled clinical trial evaluated the effect of Bifidobacterium animalis subsp. lactis (B. lactis) HN019-containing probiotic lozenges as adjuvant to scaling and root planing (SRP) in patients with generalized chronic periodontitis. MATERIALS AND METHODS: Forty-one chronic periodontitis patients were recruited and monitored clinically, immunologically, and microbiologically at baseline (before SRP) and 30 and 90 days after SRP. All patients were randomly assigned to a Test (SRP + Probiotic, n = 20) or Control (SRP + Placebo, n = 21) group. The probiotic lozenges were used twice a day for 30 days. The data were statistically analysed. RESULTS: The Test group presented a decrease in probing pocket depth and a clinical attachment gain significantly higher than those of the Control group at 90 days. The Test group also demonstrated significantly fewer periodontal pathogens of red and orange complexes, as well as lower proinflammatory cytokine levels when compared to the Control group. Only the Test group showed an increase in the number of B. lactis HN019 DNA copies on subgingival biofilm at 30 and 90 days. CONCLUSION: The use of B. lactis HN019 as an adjunct to SRP promotes additional clinical, microbiological, and immunological benefits in the treatment of chronic periodontitis (NCT03408548).

Evaluation of a bone substitute covered with a collagen membrane for ridge preservation after tooth extraction. Clinical and tomographic randomized controlled study in humans.

OBJECTIVE: To evaluate the use of a synthetic bone substitute covered with a collagen membrane for ridge preservation after tooth extraction, by clinical and tomographic analysis. MATERIAL AND METHODS: Fifteen patients, presenting at least two maxillary anterior teeth indicated for extraction, were selected: in the test group (TG), post-extraction sockets were filled by a synthetic bone substitute; in the control group (CG), by blood clot. In both groups, the sockets were covered by a collagen membrane. Cone-beam computerized tomography (CBCT) scans were acquired immediately after and 6 months post-surgically, and horizontal and vertical dimensional bone changes were quantified. RESULTS: Transurgical clinical analysis presented no statistically significant differences between TG and CG (p > .05). CBCT intragroup evaluation presented statistically significant reduction for the buccal alveolar measurement (TG = 1.58 mm or 21.82%, and CG = 1.66 mm or 24.08%) and horizontal cervical measurement (TG = 0.55 mm or 8.30% and CG = 1.30 mm or 17.68%), and not significant for palatal alveolar measurement (TG = 0.44 mm or 3.42% and CG = 0.26 mm or 3.89%). For alveolar height and horizontal apical measurements, this decrease was significant only for the CG, with reductions of 1.03 mm and 0.50 mm, respectively, compared to a decrease of 0.57 mm and 0.19 mm for the TG. The intergroup analysis showed significant difference for cervical horizontal measurement after 6 months (p < .05). CONCLUSION: The results showed that the use of the bone substitute covered with a collagen membrane resulted in less changes in vertical and horizontal alveolar ridge dimensions than the collagen membrane alone.

Effect of surgical periodontal treatment associated to antimicrobial photodynamic therapy on chronic periodontitis: A randomized controlled clinical trial.

AIM: This randomized controlled clinical trial evaluated the effects of an adjunctive single application of antimicrobial photodynamic therapy (aPDT) in Surgical Periodontal Treatment (ST) in patients with severe chronic periodontitis (SCP). MATERIAL AND METHODS: In a split-mouth design, 20 patients with SCP were treated with aPDT+ST (Test Group, TG) or ST only (Control Group, CG). aPDT was applied in a single episode, using a diode laser and a phenothiazine photosensitizer. All patients were monitored until 90 days after surgical therapy. Levels of 40 subgingival species were measured by checkerboard DNA-DNA hybridization at baseline, 60 and 150 days. Clinical and microbiological parameters were evaluated. RESULTS: In deep periodontal pockets depth (PPD ≥5 mm), Test Group presented a significantly higher decrease in PPD than Control Group at 90 days after surgical therapy (p < .05). Test Group also demonstrated significantly less periodontal pathogens of red complex (Treponema denticola) (p < .05). CONCLUSION: A single episode of aPDT used in adjunct to open flap debridement of the root surface in the surgical treatment of SCP: i) significantly improved clinical periodontal parameters; ii) eliminates periodontal pathogens of the red complex more effectively (NCT02734784).

Effect of platelet-rich plasma on the healing of mandibular defects treated with fresh frozen bone allograft: a radiographic study in dogs.

The purpose of this study was to radiographically analyze the effect of autologous platelet rich plasma (PRP) on the healing of fresh frozen bone allograft (FFBA) placed in surgically created resection defects in mandibles of dogs. Bilateral resection defects measuring 1.5 cm × 1 cm were surgically created on the inferior border of the mandible in 10 adult male dogs. The defects were randomly divided into three groups: C, FFBA, and FFBA/PRP. In Group C, the defect was filled by blood clot only. In Group FFBA, the defect was filled with particulate fresh frozen bone allograft. In Group FFBA/PRP, it was filled with particulate fresh frozen bone allograft combined with PRP. At 90 days postoperative, standardized radiographs of the mandibles were obtained and results were quantitatively evaluated. Analysis of digitized radiographs indicated that non-PRP grafts were significantly less dense than the PRP grafts. Group FFBA/PRP also presented a statistically greater mineralized tissue area than Groups C and FFBA. Within the limits of this study, it can be concluded that PRP enhanced the healing of FFBA in resection defects in mandibles of dogs.

Effect of platelet-rich plasma on bone healing of fresh frozen bone allograft in mandibular defects: a histomorphometric study in dogs.

OBJECTIVE: This study histologically analyzed the healing of fresh frozen bone allograft (FFBA) with or without platelet-rich plasma (PRP) in bony defects surgically created in the mandible of dogs. MATERIAL AND METHODS: Bilateral resection defects were surgically created on the inferior border of the mandible in 10 dogs. The defects were randomly divided into three groups: C (the defect was filled by blood clot only), FFBA (the defect was filled with particulate FFBA), and FFBA/PRP (the defect was filled with particulate FFBA combined with PRP). The animals were euthanized at 12 weeks post-surgery. Histomorphometric and histological analyses were performed. Data were statistically analyzed using Friedman test and Dunn test (P < 0.05). RESULTS: Group FFBA/PRP presented a statistically greater mineralized bone area and a smaller marrow bone area than Groups FFBA and C. CONCLUSIONS: The use of PRP improved the incorporation of FFBA, increasing the density of newly formed bone at 12 weeks post-surgery.

Effects of probiotics in rats with experimental metabolic syndrome and periodontitis: An investigation of the intestine-adipose tissue axis.

BACKGROUND: This study evaluated the systemic (intestine and adipose tissue) and local (periodontal tissues) impact of probiotic therapy in rats with metabolic syndrome (MS) associated or not with periodontitis (PE). METHODS: Forty-eight rats received a high-fat diet for induction of MS for 16 weeks. They were subdivided into groups with (+) and without (-) PE, receiving (*) or not (**) receiving probiotics (PROB): MS (-**), MSP (-*), MSPE (+**), and MSPEP (+*). PROB administration (Bifidobacterium animalis subsp. lactis HN019) started on the 8th week of the study and PE was induced on the 14th week by placing ligature on the animals' lower first molars. Euthanasia occurred in the 16th week. Biomolecular, immunoenzymatic assays, and histomorphometric analyses were performed. The data obtained were statistically analyzed (ANOVA, Tukey, p < 0.05). RESULTS: The MSPEP group exhibited reduced alveolar bone loss when compared with the MSPE group, as well as lower levels of hepatic steatosis and proteinuria (p < 0.05). In the intestinal environment, the MSPE group exhibited significantly lower villus height and crypt depth, as well as a greater increase in Bacillota when compared with the MSPEP group (p < 0.05). The MSPEP group showed lower adipokine gene expression (LEPR, NAMPT, and FABP4) in adipose tissue than the MSPE group (p < 0.05). CONCLUSION: The probiotic B. lactis HN019 reduced the severity of experimental periodontitis and modulated the expression of lipogenic genes and intestinal morphological and microbiological parameters in rats with MS.

Comparison Between Different Delivery Vehicles for the Probiotic Bifidobacterium animalis subsp. lactis HN019 on Experimental Periodontitis in Rats.

This study aimed to assess the effects of the probiotic (PROB) Bifidobacterium animalis subsp. lactis HN019 in two different delivery vehicles in experimental periodontitis (EP), including the gene expression for IL-10, IFN-γ, and FOXP3. In total, 32 rats were assigned into groups (n=8): C (control), EP, EP-PROB/Water, and EP-PROB/Milk. The probiotic was administered for 4 weeks, from baseline to euthanasia. Periodontitis was induced by ligatures 14 days after baseline. Data were statistically analyzed (p<0.05). Both probiotic groups presented decreased alveolar bone loss and increased interproximal attachment level than group EP. Also, these parameters were significantly improved in the Milk group when compared with the Water group. EP-PROB/Milk showed higher gene expression for IL-10 and lower for FOXP3 in relation to EP-PROB/Water and EP groups. The use of milk was able to potentiate the protective effects of B. lactis HN019 in rats under EP.

The use of probiotics can reduce the severity of experimental periodontitis in rats with metabolic syndrome: An immunoenzymatic and microtomographic study.

BACKGROUND: This study evaluated the effects of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019) in the development of periodontitis (PE), associated or not with metabolic syndrome, (MS) in rats. METHODS: Ninety-six rats were grouped according to a food protocol: high-fat diet for induction of MS or standard diet for the control groups (C). They were subdivided into groups with (+) and without (-) PE, receiving (*) or not (**) probiotic (PROB): C-**, CP-*, PE+**, PEP+*, MS- MSP-*, MSPE+**, and MSPEP+*. PROB administration started on the eighth week of the study and PE was induced on the 14th week by placing ligature on the animals' lower first molars. Euthanasia occurred in the 16th week. Biomolecular analyzes, immunoenzymatic assays, and microtomographic analyses were performed. The data obtained were analyzed statistically (P < 0.05). RESULTS: The PEP and MSPEP groups showed lower levels of alveolar bone loss when compared with the PE and MSPE groups, respectively (P < 0.05). The immunoenzymatic analysis showed higher levels of interleukin (IL)-1ß and a higher receptor activator of NF-kappaB ligand (RANKL)/osteoprotegerin (OPG) ratio in the MSPE group when compared with the MSPEP group (P < 0.05). The PEP group showed lower levels of tumor necrosis factor (TNF)-α and IL-6 when compared with the PE group. The use of PROB attenuated dyslipidemia parameters in animals with MS, with or without PE. CONCLUSION: B. lactis HN019 reduced more significantly the severity of PE in rats with MS, modulating both systemic metabolic and immunoinflammatory parameters in periodontal tissues.

Evaluation of Bone Response to a Nano HA Implant Surface on Sinus Lifting Procedures: Study in Rabbits.

The aim of this study was to evaluate the bone response to two different implant surfaces on sinus lift procedures in rabbits. Bilateral sinus lifting with inorganic bovine bone associated with collagen membrane and immediate implantation were performed in 16 rabbits. Custom mini-implants were randomly installed in the prepared sites: one side received a double acid-etched (DAE) surface and the other a nano-hydroxyapatite (NHA) surface. The animals were euthanized 30 and 60 days after surgery, and biopsies were collected for microtomographic and histomorphometric analysis. After 30 days, no intra- and inter-group statistical differences were observed in microtomographic analysis, while at 60 days, bone analysis showed statistically significant differences between groups (p < 0.05) for all the evaluated parameters. Histomorphometric analysis showed, after 30 days, mean % of Bone-to-Implant Contact (BIC) for DAE and NHA of 31.70 ± 10.42% vs. 40.60 ± 10.22% (p > 0.05), respectively; for % of Bone Area Fraction Occupancy (BAFO), mean values were 45.43 ± 3.597% for DAE and 57.04 ± 5.537% for NHA (p < 0.05). After 60 days, mean %BIC and %BAFO for DAE and NHA implants were statistically significant (p < 0.05). The NHA surface showed superior biological features compared to the DAE treatment, promoting higher bone formation around the implants in an experimental model of bone repair in a grafted area.

Bifidobacterium Strains Present Distinct Effects on the Control of Alveolar Bone Loss in a Periodontitis Experimental Model.

Periodontitis is an inflammatory disease induced by a dysbiotic oral microbiome. Probiotics of the genus Bifidobacterium may restore the symbiotic microbiome and modulate the immune response, leading to periodontitis control. We evaluated the effect of two strains of Bifidobacterium able to inhibit Porphyromonas gingivalis interaction with host cells and biofilm formation, but with distinct immunomodulatory properties, in a mice periodontitis model. Experimental periodontitis (P+) was induced in C57Bl/6 mice by a microbial consortium of human oral organisms. B. bifidum 1622A [B+ (1622)] and B. breve 1101A [B+ (1101)] were orally inoculated for 45 days. Alveolar bone loss and inflammatory response in gingival tissues were determined. The microbial consortium induced alveolar bone loss in positive control (P + B-), as demonstrated by microtomography analysis, although P. gingivalis was undetected in oral biofilms at the end of the experimental period. TNF-α and IL-10 serum levels, and Treg and Th17 populations in gingiva of SHAM and P + B- groups did not differ. B. bifidum 1622A, but not B. breve 1101A, controlled bone destruction in P+ mice. B. breve 1101A upregulated transcription of Il-1ß, Tnf-α, Tlr2, Tlr4, and Nlrp3 in P-B+(1101), which was attenuated by the microbial consortium [P + B+(1101)]. All treatments downregulated transcription of Il-17, although treatment with B. breve 1101A did not yield such low levels of transcripts as seen for the other groups. B. breve 1101A increased Th17 population in gingival tissues [P-B+ (1101) and P + B+ (1101)] compared to SHAM and P + B-. Administration of both bifidobacteria resulted in serum IL-10 decreased levels. Our data indicated that the beneficial effect of Bifidobacterium is not a common trait of this genus, since B. breve 1101A induced an inflammatory profile in gingival tissues and did not prevent alveolar bone loss. However, the properties of B. bifidum 1622A suggest its potential to control periodontitis.

Bone marrow coagulated and low-level laser therapy accelerate bone healing by enhancing angiogenesis, cell proliferation, osteoblast differentiation, and mineralization.

The present study evaluated bone marrow aspirate (BMA) and low-level laser therapy (LLLT) on bone healing. It was created critical-size defects (CSD) of 5 mm diameter in rat calvaria of 64 rats. Animals were randomly divided into four groups: Control (blood clot), BMA (coagulated BMA), LLLT (laser irradiation and blood clot), and BMA/LLLT (laser irradiation and coagulated BMA). Euthanasia was performed at 15 or 30 days postoperative. Immunohistochemical reactions were performed to identify vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA), runt-related transcription factor-2 (Runx2), bone morphogenetic protein-2 (BMP-2), osteocalcin (OCN), and osteopontin (OPN). The markers were quantified, and data were statistically analyzed. Groups BMA/LLLT and LLLT presented significantly higher VEGF expression than group control. Group BMA/LLLT presented a significantly higher expression of PCNA than all experimental groups. Groups BMA and BMA/LLLT presented significantly higher expression of BMP-2 than all experimental groups. Groups LLLT and BMA/LLLT presented significantly higher expression of OPN than groups control and BMA. Groups LLLT, BMA, and BMA/LLLT presented a significantly higher expression of OCN than group control. It can be concluded that the association of BMA and LLLT enhanced bone healing by improving expression of VEGF, PCNA, Runx2, BMP-2, OPN, and OCN.

Bifidobacterium animalis subsp lactis HN019 presents antimicrobial potential against periodontopathogens and modulates the immunological response of oral mucosa in periodontitis patients.

OBJECTIVE: To evaluate the effects of Bifidobacterium animalis subsp. lactis HN019 (HN019) on clinical periodontal parameters (plaque accumulation and gingival bleeding), on immunocompetence of gingival tissues [expression of beta-defensin (BD)-3, toll-like receptor 4 (TLR4), cluster of differentiation(CD)-57 and CD-4], and on immunological properties of saliva (IgA levels) in non-surgical periodontal therapy in generalized chronic periodontitis (GCP) patients. Adhesion to buccal epithelial cells (BEC) and the antimicrobial properties of HN019 were also investigated. MATERIALS AND METHODS: Thirty patients were recruited and monitored clinically at baseline (before scaling and root planing-SRP) and after 30 and 90 days. Patients were randomly assigned to Test (SRP+Probiotic, n = 15) or Control (SRP+Placebo, n = 15) group. Probiotic lozenges were used for 30 days. Gingival tissues and saliva were immunologically analyzed. The adhesion of HN019 with or without Porphyromonas gingivalis in BEC and its antimicrobial properties were investigated in in vitro assays. Data were statistically analyzed (p<0.05). RESULTS: Test group presented lower plaque index (30 days) and lower marginal gingival bleeding (90 days) when compared with Control group. Higher BD-3, TLR4 and CD-4 expressions were observed in gingival tissues in Test group than in Control group. HN019 reduced the adhesion of P. gingivalis to BEC and showed antimicrobial potential against periodontopathogens. CONCLUSION: Immunological and antimicrobial properties of B. lactis HN019 make it a potential probiotic to be used in non-surgical periodontal therapy of patients with GCP. CLINICAL RELEVANCE: B. lactis HN019 may be a potential probiotic to improve the effects of non-surgical periodontal therapy. Name of the registry and registration number (ClinicalTrials.gov): "Effects of probiotic therapy in the treatment of periodontitis"-NCT03408548.

Effect of platelet-rich plasma on bone healing of autogenous bone grafts in critical-size defects.

AIM: This study histologically analysed the effect of autogenous platelet-rich plasma (PRP), prepared according to a new semiautomatic system, on healing of autogenous bone (AB) grafts placed in surgically created critical-size defects (CSD) in rabbit calvaria. MATERIAL AND METHODS: Sixty rabbits were divided into three groups: C, AB and AB/PRP. A CSD was created in the calvarium of each animal. In Group C (control), the defect was filled by blood clot only. In Group AB (autogenous bone graft), the defect was filled with particulate autogenous bone. In Group AB/PRP (autogenous bone graft with platelet-rich plasma), it was filled with particulate autogenous bone combined with PRP. All groups were divided into subgroups (n=10) and euthanized at 4 or 12 weeks post-operatively. Histometric and histologic analyses were performed. Data were statistically analysed (anova, t-test, p<0.05). RESULTS: Group C presented significantly less bone formation compared with Group AB and AB/PRP in both periods of analysis (p<0.001). At 4 weeks, Group AB/PRP showed a statistically greater amount of bone formation than Group AB (64.44 +/- 15.0%versus 46.88 +/- 14.15%; p=0.0181). At 12 weeks, no statistically significant differences were observed between Groups AB and AB/PRP (75.0 +/- 8.11%versus 77.90 +/- 8.13%; p>0.05). It is notable that the amount of new bone formation in Group AB/PRP at 4 weeks was similar to that of Group AB at 12 weeks (p>0.05). CONCLUSION: Within its limitation, the present study has indicated that (i) AB and AB/PRP significantly improved bone formation and (ii) a beneficial effect of PRP was limited to an initial healing period of 4 weeks.

The impact of predatory bacteria on experimental periodontitis.

BACKGROUND: This study evaluated the effects of topical administration of Bdellovibrio bacteriovorus HD100 on experimental periodontitis (EP) in rats. METHODS: Thirty-two rats were divided into groups C (control), EP, C-HD100, and EP-HD100. At day 0, animals of groups EP and EP-HD100 received cotton ligatures around mandibular first molars (MFM). In groups C-HD100 and EP-HD100, 1 mL of suspensions containing B. bacteriovorus HD100 was topically administered in the subgingival region of MFMs at days 0, 3, and 7. Animals were euthanized at day 14. Gingival tissue, hemimandibles, and oral biofilm were collected. Data were statistically analyzed. RESULTS: Group EP-HD100 presented greater bone volume and lower connective tissue attachment loss (CTAL) than group EP (P < 0.05). Group EP-HD100 presented greater proportions of Actinomyces and Streptococcus-like species and lower proportions of Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Fusobacterium polymorphum, Eikenella corrodens, Eubacterium nodatum, Campylobacter gracilis, Capnocytophaga sputigena, and Veillonella parvula-like species than group EP. Group EP-HD100 presented greater levels of osteoprotegerin and gene expression of interleukin (IL)-17, IL-10, and forkhead box P3 than group EP (P < 0.05). CONCLUSION: Topical use of B. bacteriovorus HD100 promotes a protective effect against alveolar bone loss and CTAL in rats with EP.

Multiple sessions of antimicrobial photodynamic therapy associated with surgical periodontal treatment in patients with chronic periodontitis.

BACKGROUND: This double-blind, randomized, controlled clinical trial assessed the efficacy of multiple sessions of antimicrobial photodynamic therapy (aPDT) as an adjunct to surgical periodontal treatment (ST) in patients with severe chronic periodontitis (SCP). METHODS: Sixteen patients with SCP were treated with aPDT+ST (test group, TG) or ST only (control group, CG), in a split-mouth design. aPDT was applied at 0, 2, 7, and 14 postoperative days only in TG. All patients were followed up for 90 days after surgery. The following clinical and microbiological parameters were assessed: clinical attachment level (CAL), probing depth (PD), gingival recession (GR), bleeding on probing (BOP), plaque index (PI), and count of 40 subgingival microbial species (checkerboard DNA-DNA hybridization). Data were collected at baseline (preintervention), at 60 days (30 days after the end of non-surgical therapy), and at 150 days (90 days after surgery). RESULTS: A significant reduction in PD was observed at 150 days for the TG, when compared with the CG (P Ë‚ 0.05). CAL gain was significantly higher in the TG at 60 and 150 days (P Ë‚ 0.05). Changes in the subgingival microbiota were similar between the groups (P Ëƒ 0.05), but the TG revealed a larger number of bacteria associated with periodontal disease at the end of the experiment compared with the CG (P < 0.05). CONCLUSION: Multiple sessions of aPDT as an adjunct to surgical periodontal treatment significantly improved clinical parameters at 90 postoperative days.

Sub-antimicrobial doses of doxycycline decreased bone loss related to ligature-induced periodontitis in hypertensive rats.

BACKGROUND/OBJECTIVE: The beneficial effects of sub-antimicrobial dose doxycycline (SDD) associated with nonsurgical periodontal therapy are well documented. Recently, the effects of SDD on metalloproteinases have been investigated in the treatment of hypertension. The aim of this study was to evaluate the effects of SDD on ligature-induced periodontitis in spontaneously hypertensive rats (SHR). METHODS: Fifty-four adult male rats were divided into three groups: SHR-C, SHR-L and SHR-L-DOX (C - Control; L - Ligature). In group SHR-L-DOX, animals were treated with daily 5 mg/kg SDD administration. In L groups, a ligature remained around mandibular first molars for the first 10 days. Each group was divided for euthanasia at 10 or 21 days. Microtomographic and histometric analyses were performed. Osteoclastogenesis was evaluated by tartrate-resistant acid phosphatase (TRAP) assay and gene expression of 84 inflammatory mediators by polymerase chain reaction (PCR) array. RESULTS: Group SHR-L-DOX presented reduced systolic blood pressure when compared with group SHR-L at both 10 and 21 days (p < 0.05). Group SHR-L-DOX showed decreased bone and attachment loss in comparison with group SHR-L at both 10 and 21 days (p < 0.05). SDD treatment reduced the amount of TRAP-positive cells at 10 days (p < 0.05). Group SHR-L-DOX showed a downregulated inflammatory genes profile in comparison with SHR-L at 10 and 21 days. CONCLUSION: SDD therapy exerted systemic modulatory effect on inflammation with reduced periodontal tissue destruction in hypertensive rats.