Chronological analysis of periodontal bone loss in experimental periodontitis in mice.

OBJECTIVES: Periodontal disease is understood to be a result of dysbiotic interactions between the host and the biofilm, causing a unique reaction for each individual, which in turn characterizes their susceptibility. The objective of this study was to chronologically evaluate periodontal tissue destruction induced by systemic bacterial challenge in known susceptible (BALB/c) and resistant (C57BL/6) mouse lineages. MATERIAL AND METHODS: Animals, 6-8 weeks old, were allocated into three experimental groups: Negative control (C), Gavage with sterile carboxymethyl cellulose 2%-without bacteria (Sham), and Gavage with carboxymethyl cellulose 2% + Porphyromonas gingivalis (Pg-W83). Before infection, all animals received antibiotic treatment (sulfamethoxazole/trimethoprim, 400/80 mg/5 mL) for 7 days, followed by 3 days of rest. Microbial challenge was performed 3 times per week for 1, 2, or 3 weeks. After that, the animals were kept until the completion of 42 days of experiments, when they were euthanized. The alveolar bone microarchitecture was assessed by computed microtomography. RESULTS: Both C57BL/6 and BALB/c mice exhibited significant bone volume loss and lower trabecular thickness as well as greater bone porosity compared to the (C) and (Sham) groups after 1 week of microbial challenge (p < .001). When comparing only the gavage groups regarding disease implantation, time and lineage, it was possible to observe that within 1 week of induction the disease was more established in BALB/c than in C57BL/6 (p < .05). CONCLUSIONS: Our results reflected that after 1 week of microbial challenge, there was evidence of alveolar bone loss for both lineages, with the loss observed in BALB/c mice being more pronounced.

Decitabine Inhibits Bone Resorption in Periodontitis by Upregulating Anti-Inflammatory Cytokines and Suppressing Osteoclastogenesis.

DNA methylation controls several inflammatory genes affecting bone homeostasis. Hitherto, inhibition of DNA methylation in vivo in the context of periodontitis and osteoclastogenesis has not been attempted. Ligature-induced periodontitis in C57BL/6J mice was induced by placing ligature for five days with Decitabine (5-aza-2'-deoxycytidine) (1 mg/kg/day) or vehicle treatment. We evaluated bone resorption, osteoclast differentiation by tartrate-resistant acid phosphatase (TRAP) and mRNA expression of anti-inflammatory molecules using cluster differentiation 14 positive (CD14+) monocytes from human peripheral blood. Our data showed that decitabine inhibited bone loss and osteoclast differentiation experimental periodontitis, and suppressed osteoclast CD14+ human monocytes; and conversely, that it increased bone mineralization in osteoblastic cell line MC3T3-E1 in a concentration-dependent manner. In addition to increasing IL10 (interleukin-10), TGFB (transforming growth factor beta-1) in CD14+ monocytes, decitabine upregulated KLF2 (Krüppel-like factor-2) expression. Overexpression of KLF2 protein enhanced the transcription of IL10 and TGFB. On the contrary, site-directed mutagenesis of KLF2 binding site in IL10 and TFGB abrogated luciferase activity in HEK293T cells. Decitabine reduces bone loss in a mouse model of periodontitis by inhibiting osteoclastogenesis through the upregulation of anti-inflammatory cytokines via KLF2 dependent mechanisms. DNA methyltransferase inhibitors merit further investigation as a possible novel therapy for periodontitis.

Aptamers recognizing fibronectin confer improved bioactivity to biomaterials and promote new bone formation in a periodontal defect in rats.

The use of alloplastic materials in periodontal regenerative therapies is limited by their incapacity to establish a dynamic dialog with the surrounding milieu. The aim of the present study was to control biomaterial surface bioactivity by introducing aptamers to induce the selective adsorption of fibronectin from blood, thus promoting platelets activation in vitro and bone regeneration in vivo. A hyaluronic acid/polyethyleneglycole-based hydrogel was enriched with aptamers selected for recognizing and binding fibronectin. In vitro, the capacity of constructs to support osteoblast adhesion, as well as platelets aggregation and activation was assessed by chemiluminescence within 24 h. Matrices were then evaluated in a rat periodontal defect to assess their regenerative potential by microcomputed tomography (µCT) and their osteogenic capacity by Luminex assay 5, 15 and 30 d postoperatively. Aptamers were found to confer matrices the capacity of sustaining firm cell adhesion (p = 0.0377) and to promote platelets activation (p = 0.0442). In vivo, aptamers promoted new bone formation 30 d post-operatively (p < 0.001) by enhancing osteoblastic lineage commitment maturation. Aptamers are a viable surface modification, which confers alloplastic materials the potential capacity to orchestrate blood clot formation, thus controlling bone healing.

Effect of smoking on the DNA methylation pattern of the SOCS1 promoter in epithelial cells from the saliva of patients with chronic periodontitis.

BACKGROUND: The aim of the present study was to evaluate the methylation pattern in the suppressor of cytokine signaling 1 (SOCS1) gene in smokers and non-smokers with chronic periodontitis (CP). METHODS: Methylation-specific polymerase chain reaction (PCR) was performed to determine the methylation status of the SOCS1 promoter in 45 saliva samples from smokers and non-smokers with CP. RESULTS: Cells from the saliva of CP patients who smoked were 7.08 times more likely to have a methylated SOCS1 promoter than cells from the saliva of non-smoking patients. CONCLUSIONS: SOCS1 gene promoter methylation, with its potential effects on the expression of this gene, seems to be a consequence of exposure to tobacco and not to periodontal disease. Further studies are needed to elucidate the relationship between the epigenetic control of immune response gene expression, exposure to environmental factors, and the development, progression, and prognosis of CP.

Epigenetic and inflammatory events in experimental periodontitis following systemic microbial challenge.

AIM: The purpose of this study was to determine inflammatory and epigenetic features following induction of oral and gut dysbiosis in experimental periodontitis in order to examine the interplay between oral and systemic infection. MATERIALS AND METHODS: Periodontitis was induced in 6- to 8-week-old C57BL/6 mice by (a) Ligature placement (Lig group) (oral challenge); (b) P. gingivalis gavage (Pg group) (systemic challenge); and (c) the combination of the two models oral and systemic challenge (Pg + Lig). The duration of the experiment was 60 days, and the animals were then sacrificed for analyses. Alveolar bone loss was assessed, and a multiplex immunoassay was performed. Maxillae and gut tissues were immunostained for DNMT3b (de novo methylation marker), B and T lymphocyte attenuator (BTLA) and IL-18R1 (inflammation markers). RESULTS: Pg and Pg + Lig groups exhibited higher bone loss when compared to Sham. BAFF, VEGF, RANKL, RANTES and IP-10 were significantly higher with Pg gavage. Likewise, DNMT3b was overexpressed in both gut and maxilla after the Pg administration. The same pattern was observed for BTLA and IL-18R1 in gut tissues. CONCLUSIONS: The systemic microbial challenge either alone or in combination with local challenge leads to distinct patterns of inflammatory and epigenetic features when compared to simply locally induced experimental periodontitis.

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.

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.

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.

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.

Bioactive Glass Particles in Two-Dimensional and Three-Dimensional Osteogenic Cell Cultures

Abstract This study aimed to investigate the influence of a three-dimensional cell culture model and bioactive glass (BG) particles on the expression of osteoblastic phenotypes in rat calvaria osteogenic cells culture. Cells were seeded on two-dimensional (2D) and three-dimensional (3D) collagen with BG particles for up to 14 days. Cell viability and alkaline phosphatase (ALP) activity was performed. Cell morphology and immunolabeling of noncollagenous bone matrix proteins were assessed by epifluorescence and confocal microscopy. The expressions of osteogenic markers were analyzed using RT-PCR. Mineralized bone-like nodule formation was visualized by microscopy and calcium content was assessed quantitatively by alizarin red assay. Experimental cultures produced a growing cell viability rate up to 14 days. Although ALP activity at 7 days was higher on BG cultures, cells on 3D and 3D+BG had an activity decrease of ALP at 14 days. Three-dimensional conditions favored the immunolabeling for OPN and BSP and the expression of ALP and COL I mRNAs. BG particles influenced positively the OC and OPN mRNAs expression and calcified nodule formation in vitro. The results indicated that the 3D cultures and BG particles contribute to the expression of osteoblastic phenotype and to differentiated and mineralized matrix formation.

Resumo O objetivo deste estudo foi investigar a influência do modelo de cultura celular tridimensional e das partículas de vidro bioativo (BG) sobre a expressão fenotípica de culturas de células osteogênicas da calvária de ratos. As células foram mantidas em culturas sobre superfícies colágenas bi-dimensionais (2D) e em géis de colágeno tridimensional (3D) com e sem partículas de BG até 14 dias. Foram avaliadas: viabilidade celular, atividade de fosfatase alcalina (ALP), morfologia celular e imunomarcação de proteínas da matriz não-colágena do osso através de epifluorescência e microscopia confocal. As expressões de marcadores osteogênicos foram analisadas utilizando RT-PCR. A formação de nódulos mineralizados foi visualizada através de microscopia e o conteúdo de cálcio foi avaliado quantitativamente pelo Alizarina Red. As culturas experimentais produziram uma taxa crescente de viabilidade até 14 dias. Embora a atividade ALP em 7 dias tenha sido maior em culturas com BG, as células em 3D e 3D+BG apresentaram uma diminuição da atividade ALP aos 14 dias. As condições tridimensionais favoreceram a imunomarcação para OPN e BSP e a expressão de mRNAs para ALP e COL I. As partículas de BG influenciaram positivamente a expressão do mRNAs para OPN e OC e a formação de nódulos calcificados in vitro. Os resultados indicaram que as culturas em 3D e partículas BG contribuíram para a expressão do fenótipo osteoblástico e para a diferenciação e formação de matriz mineralizada.

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).

Bioactive Glass Particles in Two-Dimensional and Three-Dimensional Osteogenic Cell Cultures.

This study aimed to investigate the influence of a three-dimensional cell culture model and bioactive glass (BG) particles on the expression of osteoblastic phenotypes in rat calvaria osteogenic cells culture. Cells were seeded on two-dimensional (2D) and three-dimensional (3D) collagen with BG particles for up to 14 days. Cell viability and alkaline phosphatase (ALP) activity was performed. Cell morphology and immunolabeling of noncollagenous bone matrix proteins were assessed by epifluorescence and confocal microscopy. The expressions of osteogenic markers were analyzed using RT-PCR. Mineralized bone-like nodule formation was visualized by microscopy and calcium content was assessed quantitatively by alizarin red assay. Experimental cultures produced a growing cell viability rate up to 14 days. Although ALP activity at 7 days was higher on BG cultures, cells on 3D and 3D+BG had an activity decrease of ALP at 14 days. Three-dimensional conditions favored the immunolabeling for OPN and BSP and the expression of ALP and COL I mRNAs. BG particles influenced positively the OC and OPN mRNAs expression and calcified nodule formation in vitro. The results indicated that the 3D cultures and BG particles contribute to the expression of osteoblastic phenotype and to differentiated and mineralized matrix formation.

Benefits of Bifidobacterium animalis subsp. lactis Probiotic in Experimental Periodontitis.

BACKGROUND: This study evaluates effects of topical administration of probiotic bacteria of the genus Bifidobacterium on experimental periodontitis (EP) in rats. METHODS: Thirty-two rats were divided into groups C (control; without EP), EP (EP only), C-HN019 (control+probiotic), and EP-HN019 (EP+probiotic). On day 0 of the experiment, animals of groups EP and EP-HN019 received cotton ligatures around mandibular first molars (MFMs). In groups C-HN019 and EP-HN019, 1 mL of suspensions containing Bifidobacterium animalis subsp. lactis (B. lactis) HN019 was topically administered in the subgingival region of MFMs on days 0, 3, and 7. In groups C and EP, topical administrations were performed using a sham suspension (without probiotic). All animals were euthanized at day 14. Gingival tissue, hemimandibles, and oral biofilm were collected. Data were statistically analyzed (P <0.05). RESULTS: Group EP presented greater bone porosity, trabecular separation, and connective tissue attachment loss (CTAL) as well as reduced bone volume than all other groups (P <0.05). In group EP-HN019, there were greater proportions of Actinomyces and Streptococcus-like species and lower proportions of Veillonella parvula, Capnocytophaga sputigena, Eikenella corrodens, and Prevotella intermedia-like species than group EP. Group EP-HN019 presented greater expressions of osteoprotegerin and ß-defensins than group EP (P <0.05). Group EP presented greater levels of interleukin-1ß and receptor activator of nuclear factor-kappa B ligand than group EP-HN019 (P <0.05). CONCLUSION: Topical use of B. lactis HN019 promotes a protective effect against alveolar bone loss and CTALs attributable to EP in rats, modifying immunoinflammatory and microbiologic parameters.

Preliminary Results of Non-Surgical Periodontal Treatment in Patients With Breast Cancer Undergoing Chemotherapy.

BACKGROUND: Although priority is often given to treat the cancer itself, focus should also be directed to prevention and improvement of oral complications that may occur as a result of cancer and/or its treatment. This study compares periodontal treatment results in healthy patients and patients with breast cancer undergoing chemotherapy by monitoring clinical conditions and C-reactive-protein (CRP) levels. METHODS: Thirty-five participants were allocated to one of two groups: patients with periodontitis (P) (n = 18) and patients with breast cancer and periodontitis (CAN/P) (n = 17). The following clinical parameters were assessed at baseline and 45, 90, and 180 days after non-surgical periodontal treatment (NSPT): 1) probing depth (PD); 2) clinical attachment level (CAL); 3) plaque index (PI); 4) gingival index (GI); 5) CRP; and 6) complete blood count. Clinical parameters and CRP levels were statistically analyzed. RESULTS: P and CAN/P groups presented a statistically significant decrease in PD after NSPT at 45, 90, and 180 days compared with baseline (P <0.05). There was a CAL gain in the P group and a significant reduction in PI and GI at 45, 90, and 180 days for both groups (P <0.05). At 180 days after NSPT treatment, the CAN/P group showed a higher number of residual pockets (P <0.05) compared with the P group (46.48 ± 26.80 and 7.58 ± 7.40, respectively). The P group demonstrated a significant reduction in CRP levels at 45 and 180 days after NSPT compared with baseline (P <0.05), whereas this reduction was not observed in the CAN/P group. CONCLUSION: Patients with breast cancer who were undergoing chemotherapy responded to periodontal non-surgical therapy, although with less favorable results than patients with periodontitis without cancer, and may require additional or adjunctive periodontal treatments.

Antimicrobial photodynamic therapy as an alternative to systemic antibiotics: results from a double-blind, randomized, placebo-controlled, clinical study on type 2 diabetics.

AIM: This double-blind, placebo-controlled clinical study compared multiple applications of the antimicrobial photodynamic therapy (aPDT) treatment protocol, to systemic doxycycline as adjuvant to scaling and root planing (SRP) on type 2 diabetic patients on clinical, systemic and immune-inflammatory outcomes. MATERIALS AND METHODS: Thirty patients with Hba1c >7% were allocated in two groups, SRP + Doxy (n = 15) using systemic doxycycline 100 mg/day (14 days) and SRP + aPDT (n = 15) with multiple applications (0, 3, 7 and 14 days). Primary outcome was glycated haemoglobin levels (HbA1c). Clinical parameters: plaque score (PS), bleeding on probe, probing depth, suppuration, gingival recession, and clinical attachment level, percentage of pockets with desired clinical endpoint were measured at baseline and 3 months after therapy. Cytokine profile was assessed at 0, 1 and 3 month to measure IL1-ß, TNF-α and TGF-ß on gingival crevicular fluid. RESULTS: No significant difference was detected on HbA1c, between treatments. The SRP + aPDT group showed advantage on reducing moderate pockets in single-rooted teeth at 3 months. SRP + aPDT presented better results at 3 months on IL1-ß levels. There were no significant differences between TNF-α and TGF-ß. CONCLUSIONS: Both treatments improved clinical and systemic outcomes (Hba1c). SRP + aPDT performed better in moderate probing pocket depth on single-rooted teeth, reduced favourably inflammation in short term, and may be an alternative to systemic antibiotics. (Clinicaltrials.org ID NCT01595594).

Influence of periodontal tissue thickness on buccal plate remodelling on immediate implants with xenograft.

AIM: To evaluate the influence of gingival thickness and bone grafting on buccal bone plate remodelling after immediate implant placement in sockets with thin buccal bone, using a flapless approach. MATERIALS AND METHODS: The gingiva of eight dogs was thinned at one side of the mandible, mandibular premolars were extracted without flaps, and four implants were installed on each side at 1.5 mm from the buccal bone. The sites were randomly assigned into: TG (test group) = thin gingiva; TG + GM (TG with grafting material); CG (control group) = normal gingiva; and CG + GM (CG with grafting material). After 12 weeks the dogs were sacrificed and the samples were processed for histological analysis. RESULTS: All animals exhibited a thin buccal bone initially. In all the experimental groups the buccal gap was filled with newly formed bone and the buccal bone level was slightly apical to the implant shoulder. There were no statistically significant differences among the groups for the histomorphometric parameters. CONCLUSIONS: The thickness of the buccal bone was a fundamental factor in buccal bone plate resorption, even with flapless implantation. The gingival thickness or the addition of a biomaterial in the gap did not influence the results.

Antimicrobial photodynamic therapy as an adjunct to non-surgical treatment of aggressive periodontitis: a split-mouth randomized controlled trial.

BACKGROUND: The management of aggressive periodontitis (AgP) represents a challenge for clinicians because there are no standardized protocols for an efficient control of the disease. This randomized controlled clinical trial evaluated the effects of repeated applications of antimicrobial photodynamic therapy (aPDT) adjunctive to scaling and root planing (SRP) in patients with AgP. METHODS: Using a split-mouth design, 20 patients with generalized AgP were treated with aPDT + SRP (test group) or SRP only (control group). aPDT was applied at four periods. All patients were monitored for 90 days. Clinical, microbiologic, and immunologic parameters were statistically analyzed. RESULTS: In deep periodontal pocket analysis (probing depth [PD] ≥ 7 mm at baseline), the test group presented a decrease in PD and a clinical attachment gain significantly higher than the control group at 90 days (P < 0.05). The test group also demonstrated significantly less periodontal pathogens of red and orange complexes and a lower interleukin-1ß/interleukin-10 ratio than the control group (P < 0.05). CONCLUSION: The application of four sessions of aPDT, adjunctive to SRP, promotes additional clinical, microbiologic, and immunologic benefits in the treatment of deep periodontal pockets in single-rooted teeth in patients with AgP.

The influence of the periodontal biotype on peri-implant tissues around immediate implants with and without xenografts. Clinical and micro-computerized tomographic study in small Beagle dogs.

OBJECTIVE: Soft tissues and buccal bone plate remodeling after immediate implantation in sockets with thin buccal bone, using the flapless approach with or without bone graft into the buccal gap, was compared between sites with thin and normal gingiva. MATERIAL AND METHODS: Eight dogs had the gingiva of one side of the mandible thinned, the mandibular premolars were extracted without flaps, and 4 implants were installed in each side, positioned 1.5 mm from the buccal bone. The sites were randomly assigned into: TG (test group) = thin gingiva; TG + GM (TG with grafting material); CG (control group) = normal gingiva; and CG + GM (CG with grafting material). Buccal bone thickness (BBT), thickness of keratinized tissue (TKT), alveolar thickness (AT), gingival recession (GR), and probing depth (PD) were clinically evaluated. Within 12 weeks the dogs were sacrificed and the samples were analyzed by micro-computerized tomography. RESULTS: A thin BBT was observed in all the dogs. The presurgical procedures reduced TKT in the test group, with minimal changes of the AT. There were no statistically significant differences among the groups for the clinical parameters and the tomographic analysis showed similar linear and tri-dimensional bone reduction in all the groups. CONCLUSION: The thickness of the buccal bone was a fundamental factor in buccal bone plate resorption, even with flapless implantation. The decrease in gingival thickness or the addition of a biomaterial in the gap did not influence the results.

Adjunctive effect of antimicrobial photodynamic therapy to nonsurgical periodontal treatment in smokers: a randomized clinical trial.

The aim of this study was to investigate the adjunctive effect of antimicrobial photodynamic therapy (aPDT) to scaling and root planing (SRP) in smokers with chronic periodontitis. Twenty subjects had two contralateral teeth randomly assigned to receive SRP (SRP group) or SRP + a single episode of aPDT (SRP + aPDT group), with a diode laser and a phenothiazine photosensitizer. Plaque index, bleeding on probing, probing depth (PD), clinical attachment level (CAL), and gingival recession were recorded, and gingival crevicular fluid was collected for assay of IL-1ß and matrix metalloproteinase (MMP)-8 levels. There was a significant PD reduction (SRP 1.81 ± 0.52 mm/SRP + aPDT 1.58 ± 1.28 mm; p < 0.001) and a significant CAL gain (SRP 1.60 ± 0.92 mm/SRP + aPDT 1.41 ± 1.58 mm; p < 0.001) for both groups. Significant differences were not observed in between-group comparisons. IL-1ß level in gingival crevicular fluid was higher in SRP group after 1 week (SRP 24.65 ± 18.85 pg/µL/SRP + aPDT 34.07 ± 24.81 pg/µL; p = 0.048), and MMP-8 level was higher in SRP group after 12 weeks (SRP 303.31 ± 331.62 pg/µL/SRP + aPDT 534.23 ± 647.37 pg/µL; p = 0.024). There were no statistically significant differences in intragroup comparisons. The adjunctive effect of aPDT did not warrant improvements on clinical parameters in smokers. However, it resulted in a suppression of IL-1ß and MMP-8 when compared with SRP alone.