Association between periodontitis and Alzheimer's disease and its impact on the self-perceived oral health status: a case-control study.

PURPOSE: To test the hypothesis that periodontitis is associated with AD and search whether periodontal and other variables would negatively impact the oral health-related quality of life (OHRQoL) perception. MATERIALS AND METHODS: Oral examinations and interview on self-perceived oral health status (Geriatric Oral Health Assessment Index (GOHAI) questionnaire (higher score corresponds to better perceived oral status)) were carried out and socio-demographic data were collected from outpatients with mild to moderate AD (cases, n = 50) and from their age- and sex-matched family caregivers (controls, n = 52). Full-mouth periodontal examination was performed. Significance of differences between groups was sought by chi-square, Student's t, or the Mann-Whitney test. The association between the variables periodontitis, probing depth (PD) ≥ 5 mm, and clinical attachment loss (CAL) ≥ 5 mm with the variable group was tested in binary logistic regression models (LRMs). LRMs were used to test the association of oral findings, demographics, and group with GOHAI. RESULTS: Cases had fewer teeth and greater CAL than controls. Cases had a superior percentage of sites with plaque, calculus, and bleeding on probing than controls. Cases had greater GOHAI scores than controls. Periodontitis was a variable most likely associated with AD (OR = 11.08, p < 0.001). None of the oral findings or demographics, but group, was associated with GOHAI (OR = 14.45, p < 0.001). CONCLUSION: Periodontitis is associated with AD, but not with patients' OHRQoL. CLINICAL RELEVANCE: Health care professionals must be aware that AD patients should have a periodic thorough oral examination and preventive intervention aiming at their welfare and maintenance of a pain-free functional dentition.

The effects of sodium alendronate on socket healing after tooth extraction: a systematic review of animal studies.

The aim of this systematic review was to answer the following question: "Does alendronate, a nitrogen-containing bisphosphonate, improve or impair alveolar socket healing after tooth extraction in animal models"? To this end, a systematic review of the literature was carried out in PubMed, Scopus, LILACS, Web of Science, as well as in the gray literature up to May 2023. Preclinical studies that evaluated alveolar healing after tooth extraction and the intake of sodium alendronate compared with placebo were included. Two investigators were responsible for screening the articles independently, extracting the data, and assessing their quality through the SYRCLE's RoB tool for randomized trials in animal studies. The study selection process, study characteristics, risk of bias in studies, impact of alendronate on bone healing, and certainty of evidence were described in text and table formats. Methodological differences among the studies were restricted to the synthesis methods. The synthesis of qualitative results followed the Synthesis Without Meta-analysis (SWiM) reporting guideline. From the 19 included studies, five were considered to have low risk, three were of unclear risk, and eleven presented a high risk of bias. The studies were considered heterogeneous regarding alendronate posology, including its dosage and route of administration. Furthermore, a variety of animal species, different age ranges, diverse teeth extracted, and exposure or not to ovariectomy contributed to the lack of parity of the selected studies. Our results indicated that alendronate monotherapy negatively affects the early phase of wound healing after tooth extraction in preclinical studies, suggesting that the bone resorption process after tooth extraction in animals treated with alendronate might impair the bone healing process of the extraction socket. In conclusion, alendronate administration restrains bone resorption, thereby delaying alveolar socket healing . Future studies should be conducted to validate these findings and to better understand the effects of alendronate therapy on oral tissues.

Clinical and microbiological effects of systemic antimicrobials combined to an anti-infective mechanical debridement for the management of aggressive periodontitis: a 12-month randomized controlled trial.

AIM: To compare the 1-year clinical and microbiological outcomes of an enhanced anti-infective therapy with versus without systemic antimicrobials in patients with generalized aggressive periodontitis (GAP). METHODS: In this 12-month randomized, double-blinded, placebo-controlled trial, 35 individuals assigned to a control (n = 17) or test group (n = 18) received full-mouth supra and subgingival ultrasonic debridement followed by scaling and root planing with chlorhexidine rinsing, brushing, and irrigation. Subjects received either amoxicillin (AMX, 500 mg) + metronidazole (MET, 250 mg) or placebos, TID for 10 days. Subgingival samples were obtained and analysed for their composition by checkerboard. Data were subjected to non-parametric tests. RESULTS: Both therapeutic protocols resulted in similar significant clinical improvement for most parameters at 1 year (p < 0.01). The AMX + MET group exhibited shallower residual pockets than the placebo (p = 0.05). Most periodontal pathogens decreased, whereas beneficial bacteria increased in counts in both groups over time (p < 0.0012). High levels of some periodontal and other microbial pathogens were associated with disease persistence regardless treatment. CONCLUSIONS: The enhanced anti-infective mechanical therapy is comparable with its combination with systemic AMX+MET for most clinical parameters and for maintaining low levels of periodontal pathogens for up to 1 year after treatment of GAP.

Effects of oral wound on the neutrophil lineage in murine bone-marrow: Modulation mechanism hindered by chlorhexidine.

OBJECTIVE: The oral cavity undergoes frequent stress caused by repeated mechanical trauma, and the constant contact of the injured oral mucosa with bacteria leads to the production of various pro-inflammatory cytokines and chemokines. Neutrophils play essential roles in the acute inflammation against the invasive microbiota, and compromised neutrophil recruitment hinders the bacterial clearance and worsens periodontitis. In this study, we aimed to explore whether wounding at the oral cavity would have an impact on the neutrophil lineage, and, if so, whether microbial contamination of the wounded surface plays significant roles. METHODS: We developed a surgical model of an oral wound (palate wound), by a small incision in the hard palate of the mice. We also evaluated the effect of chlorhexidine on oral wound-induced neutrophilia of bone-marrow. RESULTS: We demonstrated an increased neutrophilia in the bone-marrow of the oral wound group, as well as decreasedex vivoneutropoietic potential, in both IL-3 and GM-CSF-driven bone-marrow cultures. Washing of the entire oral cavity with chlorhexidine before surgery abolished the bone-marrow neutrophilia in the oral wound group and increased neutropoiesis in culture, relative to the saline-treated oral wound control group. Co-located treatment (both chlorhexidine treatment and wound on the right side of the palate) resulted in significantly reduced bone-marrow neutrophilia, compared to the mismatched treatment (chlorhexidine treatment and wound on opposite sides of the palate). Neither neutrophilia nor decreased neutropoiesis were dependent on glucocorticoid signaling. CONCLUSIONS: The prophylactic use of chlorhexidine ameliorates the neutrophilic response on the bone marrow, restoring the neutrophil numbers.

Ionic concentration in periradicular medium after dissolution of endodontic file fragments: an in vitro study.

The aim of this study was to obtain ionic quantification in periradicular medium after diffusion tests of the solution used inside root canals during the electrochemical dissolution of endodontic file fragments and the NiTi-containing dissolution product via an apical foramen. Thirty single-rooted extracted human teeth had root canals prepared and were attached to Eppendorf tubes filled with sterile saline. The samples were divided into 3 groups (n = 10) according to the solution used inside the root canal during the diffusion tests: Group 1: [NaF 12 g/L + NaCl 1 g/L]; Group 2: [NaF 12 g/L + NaCl 1 g/L + NiTi 0.50 g/L]; Group 3: [NaF 6 g/L + NaCl 0.5 g/L + NiTi 0.25 g/L]. The sample in each Eppendorf tube was then analyzed to assay the ionic quantification in periradicular medium. The groups were compared in relation to ionic quantifications (Kruskal-Wallis and Dunn's tests, p ≤ 0.05). Group 2 showed significantly higher F-, Ni and Ti quantities than groups 1 and 3 (p < 0.05). Group 3 showed significantly higher Ti and Ni quantities than group 1, where no measurable quantities of Ti and Ni were observed (p < 0.05). The conclusions were that a 50% dilution of the NiTi-containing dissolution product resulted in significantly lower F-, Ni and Ti quantities compared to the undiluted product. The quantifications observed here suggest that irrigation is recommendable during the electrochemical dissolution process to reduce the resultant ion concentrations in both the root canal and the periradicular medium.

Kinin danger signals proteolytically released by gingipain induce Fimbriae-specific IFN-gamma- and IL-17-producing T cells in mice infected intramucosally with Porphyromonas gingivalis.

Porphyromonas gingivalis, a Gram-negative bacterium that causes periodontitis, activates the kinin system via the cysteine protease R-gingipain. Using a model of buccal infection based on P. gingivalis inoculation in the anterior mandibular vestibule, we studied whether kinins released by gingipain may link mucosal inflammation to T cell-dependent immunity through the activation of bradykinin B(2) receptors (B(2)R). Our data show that P. gingivalis W83 (wild type), but not gingipain-deficient mutant or wild-type bacteria pretreated with gingipain inhibitors, elicited buccal edema and gingivitis in BALB/c or C57BL/6 mice. Studies in TLR2(-/-), B(2)R(-/-), and neutrophil-depleted C57BL/6 mice revealed that P. gingivalis induced edema through the sequential activation of TLR2/neutrophils, with the initial plasma leakage being amplified by gingipain-dependent release of vasoactive kinins from plasma-borne kininogens. We then used fimbriae (Fim) Ag as a readout to verify whether activation of the TLR2-->PMN-->B(2)R axis (where PMN is polymorphonuclear neutrophil) at early stages of mucosal infection had impact on adaptive immunity. Analyzes of T cell recall responses indicated that gingipain drives B(2)R-dependent generation of IFN-gamma-producing Fim T cells in submandibular draining lymph nodes of BALB/c and C57BL/6 mice, whereas IL-17-producing Fim T cells were generated only in BALB/c mice. In summary, our studies suggest that two virulence factors, LPS (an atypical TLR2 ligand) and gingipain, forge a trans-cellular cross-talk between TLR2 and B(2)R, thus forming an innate axis that guides the development of Fim-specific T cells in mice challenged intrabuccally by P. gingivalis. Ongoing research may clarify whether kinin-driven modulation of T cell responses may also influence the severity of chronic periodontitis.

Impact of systemic antimicrobials combined with anti-infective mechanical debridement on the microbiota of generalized aggressive periodontitis: a 6-month RCT.

AIM: To compare the effects of systemic amoxicillin (AMX) plus metronidazole (MET) or placebos combined with anti-infective mechanical debridement on the sub-gingival microbiota of generalized aggressive periodontitis (GAP). MATERIAL AND METHODS: The study was a 6-month randomized, double-blinded, placebo-controlled clinical trial. Thirty-one subjects received full-mouth ultrasonic debridement followed by scaling and root planing with chlorhexidine rinsing, brushing and irrigation. During mechanical therapy, subjects received systemic AMX (500mg)+MET (250mg) or placebo, t.i.d. for 10 days. Sub-gingival samples were obtained from each patient and analysed for their composition by checkerboard at baseline, 3 and 6 months post-therapy. Significant differences between groups over time were examined by General Linear Model of Repeated Measures. RESULTS: High levels of periodontal pathogens, as well as some "non-periodontal" species were observed. Most of the periodontal pathogens decreased significantly over time (p<0.05), whereas "non-periodontal" bacteria tended to increase in both groups. Sites that showed attachment loss and probing depth increase harboured higher levels of Dialister pneumosintes, Campylobacter rectus, Fusobacterium necrophorum, Prevotella tannerea and Peptostreptococcus anaerobius than sites that improved after both therapies (p<0.05). CONCLUSIONS: Systemic AMX+MET or placebos adjunctive to anti-infective mechanical debridement were comparable in lowering periodontal pathogens up to 6 months after treatment. Species not commonly associated with GAP were less affected by both therapies.

Alendronate improves bone density and type I collagen accumulation but increases the amount of pentosidine in the healing dental alveolus of ovariectomized rabbits.

BACKGROUND: It has been shown that the oral aminobisphosphonate sodium alendronate (ALN) therapy reduces the risk of main fractures in osteoporotic women, but its effect on the jaw bones is poorly known. Here, we hypothesized that ALN affects the newly formed alveolar bone, particularly the quality of the type I collagen cross-linking. METHODS: Osteoporosis was induced by ovariectomy (OVX) in 6-month old rabbits. Six weeks following surgery, eight animals were treated by oral gavage with ALN (OVX + ALN) and ten received placebo (OVX + Pbo). Another six rabbits which were sham operated also received placebo (SHAM + Pbo). One month following the beginning of treatment, the upper and lower left first premolars were removed. Six weeks later, the upper and the lower right first premolars were also extracted. One month after the second extraction, biopsies were collected from the maxillary extraction sites and collagen crosslinks were analyzed in the newly formed bone tissue by HPLC. Also, at this time, mandibular bone segments were subjected to µCT. RESULTS: Animals treated with ALN achieved a roughly 2-time greater bone volume fraction value at a late healing period than animals in the other groups (p < 0.05). Collagen mean results were 2- to 4-times superior in the OVX + ALN group than in the control groups (p < 0.05). ALN-treated animals presented higher amounts of the non-enzymatic collagen cross-link pentosidine (PEN) than the sham-operated rabbits (p < 0.05), whereas the OVX + Pbo group presented the highest amount of PEN (p < 0.05). CONCLUSION: Alendronate increases bone volume and collagen accumulation, but does not fully rescue the non-osteoporotic alveolar tissue quality as is evident from the increased quantity of pentosidine.

The effects of sodium alendronate on socket healing after tooth extraction: a systematic review of animal studies

Abstract The aim of this systematic review was to answer the following question: "Does alendronate, a nitrogen-containing bisphosphonate, improve or impair alveolar socket healing after tooth extraction in animal models"? To this end, a systematic review of the literature was carried out in PubMed, Scopus, LILACS, Web of Science, as well as in the gray literature up to May 2023. Preclinical studies that evaluated alveolar healing after tooth extraction and the intake of sodium alendronate compared with placebo were included. Two investigators were responsible for screening the articles independently, extracting the data, and assessing their quality through the SYRCLE's RoB tool for randomized trials in animal studies. The study selection process, study characteristics, risk of bias in studies, impact of alendronate on bone healing, and certainty of evidence were described in text and table formats. Methodological differences among the studies were restricted to the synthesis methods. The synthesis of qualitative results followed the Synthesis Without Meta-analysis (SWiM) reporting guideline. From the 19 included studies, five were considered to have low risk, three were of unclear risk, and eleven presented a high risk of bias. The studies were considered heterogeneous regarding alendronate posology, including its dosage and route of administration. Furthermore, a variety of animal species, different age ranges, diverse teeth extracted, and exposure or not to ovariectomy contributed to the lack of parity of the selected studies. Our results indicated that alendronate monotherapy negatively affects the early phase of wound healing after tooth extraction in preclinical studies, suggesting that the bone resorption process after tooth extraction in animals treated with alendronate might impair the bone healing process of the extraction socket. In conclusion, alendronate administration restrains bone resorption, thereby delaying alveolar socket healing . Future studies should be conducted to validate these findings and to better understand the effects of alendronate therapy on oral tissues.

Periodontal status of patients with dentin dysplasia type I: report of three cases within a family.

BACKGROUND: Dentin dysplasia type I (DDI) is a rare hereditary disturbance of dentin formation. It is characterized by clinically normal-appearing crowns; obliteration of pulp chambers; and short, blunted and malformed roots that are commonly associated with periodontal attachment loss (PAL). In this context, we report three cases within a family with similar clinical and radiographic features of DDI but with differing microbiologic and periodontal conditions. METHODS: A 42-year-old white female and her two daughters (25 and 10 years of age) presented with a diagnosis of DDI. Probing depth (PD), clinical attachment level (CAL), visible plaque, and bleeding on probing (BOP) were recorded. Subgingival biofilm samples were randomly collected and analyzed by checkerboard DNA-DNA hybridization. RESULTS: The mother presented 34.9% of sites with PD > or =4 mm, 41.3% of sites with CAL > or =4 mm, and 57% of sites with BOP; both daughters presented no sites with PD or CAL >3 mm and <10% of sites with BOP. Microbiologic analysis detected Gemella morbillorum, Neisseria mucosa, and Staphylococcus aureus in > or =50% of the mother's samples. The daughters showed high levels (>10(4) bacterial cells) of some periodontopathic bacteria, including members of the red (Porphyromonas gingivalis) and orange (Fusobacterium periodonticum and F. nucleatum polymorphum) complexes and beneficial species of the yellow (Streptococcus gordonii) and purple (Veillonella parvula) complexes. The mother presented high mean levels only for four tested species (N. mucosa, Prevotella melaninogenica, Treponema denticola, and V. parvula). CONCLUSION: A combination of radiographs, microbiologic analysis, and preventive professional monitoring care is important to avoid PAL and to provide oral health in patients with DDI.

Comparison between full-mouth scaling and root planing and quadrant-wise basic therapy of aggressive periodontitis: 6-month clinical results.

BACKGROUND: The aim of this study was to test the hypothesis that there are no differences in clinical parameters in generalized aggressive periodontitis patients after full-mouth scaling and root planing (FRP) or quadrant-wise basic periodontal therapy (BPT) when combined with an antibiotic regimen. METHODS: Patients were allocated randomly to BPT (N = 15; mean age: 29.5 +/- 5.7 years) or FRP (N = 15; mean age: 28.4 +/- 5.7 years). All subjects received oral hygiene instructions including the use of a 0.12% chlorhexidine mouthrinse solution twice a day for 2 months. Patients also received amoxicillin, 500 mg, and metronidazole, 250 mg, three times a day for 7 days. Probing depth (PD), clinical attachment level, visible plaque, and bleeding on probing were recorded at baseline and at 2, 4, and 6 months post-therapy. Statistically significant changes within and between groups were determined using the general linear model repeated measures procedure. RESULTS: Both groups showed a significant improvement in all clinical parameters post-therapy, which was particularly evident at 2 months in the sites that had been deepest at baseline. For instance, the mean PD at sites with mean PD > or =7 mm at baseline had decreased 3.9 mm in the BPT group and 3.6 mm in the FRP group. At 6 months, the percentage of sites with PD > or =7 mm decreased from 13.2% +/- 3.2% to 0% in the BPT group and from 13.3% +/- 3.5% to 0.2% +/- 0.1% in the FRP group. No statistically significant differences were observed between groups for most clinical parameters. CONCLUSION: Within the limits of the present investigation, FRP and BPT caused comparable clinical effects in aggressive periodontitis patients when an adjunctive combined antibiotic regimen was included.

Treatment of gingival overgrowth in a child with Bardet-Biedl syndrome.

BACKGROUND: Bardet-Biedl syndrome (BBS) is a rare, heterogeneous, autosomal recessive condition, primarily characterized by polydactyly, obesity, mental retardation, hypogonadism, retinopathy, and renal failure. Dental anomalies, regarded as secondary manifestations, include hypodontia, microdontia, short roots, and deep palate. Few reports in the literature have described the oral manifestations of BBS. This article reports a case of BBS in a boy who presented some typical oral manifestations added to a generalized gingival overgrowth, an anomaly that had not been reported previously in patients with this syndrome. METHODS: A 12-year-old white male presented with a diagnosis of BBS and chief complaint of gingival enlargement in the anterior segment of both arcades. The treatment plan included surgical removal of the overgrown gingiva followed by orthodontic therapy. The excised tissues were submitted to histologic analysis. RESULTS: There was no sign of recurrence 1 year after gingivectomy. Histopathology revealed a dense connective tissue with a mild inflammatory infiltrate, irregularly arranged fiber bundles, and epithelial acanthosis, which is characteristic of gingival overgrowth. CONCLUSIONS: The gingival overgrowth was treated successfully by gingivectomy. The periodontal surgery minimized the functional, social, and emotional consequences of the oral manifestation associated with the syndrome.

Ionic concentration in periradicular medium after dissolution of endodontic file fragments: an in vitro study

Abstract The aim of this study was to obtain ionic quantification in periradicular medium after diffusion tests of the solution used inside root canals during the electrochemical dissolution of endodontic file fragments and the NiTi-containing dissolution product via an apical foramen. Thirty single-rooted extracted human teeth had root canals prepared and were attached to Eppendorf tubes filled with sterile saline. The samples were divided into 3 groups (n = 10) according to the solution used inside the root canal during the diffusion tests: Group 1: [NaF 12 g/L + NaCl 1 g/L]; Group 2: [NaF 12 g/L + NaCl 1 g/L + NiTi 0.50 g/L]; Group 3: [NaF 6 g/L + NaCl 0.5 g/L + NiTi 0.25 g/L]. The sample in each Eppendorf tube was then analyzed to assay the ionic quantification in periradicular medium. The groups were compared in relation to ionic quantifications (Kruskal-Wallis and Dunn's tests, p ≤ 0.05). Group 2 showed significantly higher F-, Ni and Ti quantities than groups 1 and 3 (p < 0.05). Group 3 showed significantly higher Ti and Ni quantities than group 1, where no measurable quantities of Ti and Ni were observed (p < 0.05). The conclusions were that a 50% dilution of the NiTi-containing dissolution product resulted in significantly lower F-, Ni and Ti quantities compared to the undiluted product. The quantifications observed here suggest that irrigation is recommendable during the electrochemical dissolution process to reduce the resultant ion concentrations in both the root canal and the periradicular medium.

Guided bone regeneration of a pronounced gingivo-alveolar cleft due to orthodontic space closure.

BACKGROUND: Gingival invagination is a relatively common occurrence following orthodontic closure of extraction sites. The present paper reports a combined periodontal and orthodontic treatment in a patient with a severe gingivo-alveolar cleft due to orthodontic closure of maxillary central incisor extraction space. METHODS: A definite interdental gingival cleft, extending 8 mm into the alveolar bone, required the correction of the gingival deformity as a first step, followed by guided bone regeneration (GBR). The GBR approach included the emptying of the incisive foramen to approximately 5 mm in depth followed by the insertion of bioabsorbable hydroxyapatite and covering with a bioabsorbable barrier membrane. Six months afterward, the orthodontic therapy was resumed. RESULTS: Radiographs and clinical examination 4 years after the completion of therapy indicates functionally and aesthetically satisfactory and stable results. CONCLUSION: The present paper illustrates an additional application for the guided bone regeneration technique.

Ligneous periodontitis and Ehlers-Danlos syndrome.

BACKGROUND: Generalized membranous gingival enlargement due to an accumulation of fibrin deposits associated with severe alveolar bone loss (ligneous periodontitis) is a rare condition, and plasminogen deficiency seems to play a central role in its pathogenesis. However, this condition has not been described in association with syndromes. This article reports a case of ligneous periodontitis in a boy with the classic type of Ehlers-Danlos syndrome (EDS). METHODS: A 12-year-old white male presented with generalized gingival overgrowth and severe alveolar bone loss. A physical examination revealed clinical signs of EDS (velvety skin with mild hyperextensibility, marked hypermobility of the limb joints, atrophic scars on his knees, and easy bruising), which is associated with a positive family history for joint hypermobility. A biopsy of gingival tissues was submitted for routine histology, hematoxylin and eosin (H&E), and direct immunofluorescence (antifibrinogen). An evaluation of plasminogen activity was also performed. RESULTS: Histopathology revealed chronic periodontitis with fibrinoid material deposition, and direct immunofluorescence proved to be positive for fibrin. Functional plasminogen was reduced. A conclusive diagnosis of ligneous periodontitis due to plasminogen deficiency associated with the classic type of EDS was rendered. CONCLUSIONS: Ehlers-Danlos syndrome can be associated with ligneous periodontitis. In the present case, the histologic examination represented an important tool in the differential diagnosis, because it ruled out EDS type VIII as the associated systemic factor to periodontal breakdown.

Oral health impacts on daily living related to four different treatment protocols for chronic periodontitis.

BACKGROUND: The aims of this study were to evaluate the oral health impacts perceived by patients submitted to different treatments of chronic periodontitis and their association with clinical parameters. METHODS: Sixty patients were assigned to one of the following therapeutic groups: control, treated with full-mouth scaling and root planing (SRP); test 1, treated with SRP and 400 mg systemically administered metronidazole (MET) three times per day for 10 days; test 2, treated with SRP and professional supragingival plaque removal (PP) every week for 3 months; and test 3, treated with SRP and MET plus PP. Clinical periodontal measurements and data regarding patients' oral health impacts (perceived impacts on bleeding gums, gingival recession, sensitivity to cold, packing foods, aesthetics, bad breath, and tooth mobility) were collected at baseline and 3 months after therapy. RESULTS: All groups presented significant improvement in oral health perceived impacts. There was no statistically significant difference in the improvement of oral health impacts among groups subjected to different treatments. The clinical data of percentage of deep probing depth, deep clinical attachment level, and bleeding on probing were found to be correlated significantly with oral health impacts. CONCLUSIONS: Periodontal treatment leads to a significant reduction of self-perceived impacts regardless of the non-surgical treatment protocol employed. Most of the clinical data were associated with oral health impacts.

Long-term evaluation of the antimicrobial susceptibility and microbial profile of subgingival biofilms in individuals with aggressive periodontitis.

This study evaluates the antimicrobial susceptibility and composition of subgingival biofilms in generalized aggressive periodontitis (GAP) patients treated using mechanical/antimicrobial therapies, including chlorhexidine (CHX), amoxicillin (AMX) and metronidazole (MET). GAP patients allocated to the placebo (C, n = 15) or test group (T, n = 16) received full-mouth disinfection with CHX, scaling and root planning, and systemic AMX (500 mg)/MET (250 mg) or placebos. Subgingival plaque samples were obtained at baseline, 3, 6, 9 and 12 months post-therapy from 3-4 periodontal pockets, and the samples were pooled and cultivated under anaerobic conditions. The minimum inhibitory concentrations (MICs) of AMX, MET and CHX were assessed using the microdilution method. Bacterial species present in the cultivated biofilm were identified by checkerboard DNA-DNA hybridization. At baseline, no differences in the MICs between groups were observed for the 3 antimicrobials. In the T group, significant increases in the MICs of CHX (p < 0.05) and AMX (p < 0.01) were detected during the first 3 months; however, the MIC of MET decreased at 12 months (p < 0.05). For several species, the MICs significantly changed over time in both groups, i.e., Streptococci MICs tended to increase, while for several periodontal pathogens, the MICs diminished. A transitory increase in the MIC of the subgingival biofilm to AMX and CHX was observed in GAP patients treated using enhanced mechanical therapy with topical CHX and systemic AMX/MET. Both protocols presented limited effects on the cultivable subgingival microbiota.

Quantification and localization of platelet-derived growth factor in gingiva of periodontitis patients.

BACKGROUND: Platelet-derived growth factor (PDGF) is a mitogen and chemoattractant for cells of mesenchymal origin. Over-expression of PDGF-B can promote formation of inflammatory lesions in the lungs of transgenic mice. Moreover, continuous exposure to PDGF inhibits collagen production by osteoblastic cells. Thus, the expression of mitogenic factors in an inflammatory context may limit the differentiated function of cells, and thereby limit repair following periodontal attachment and bone loss. The goals of the present study were to test whether PDGF is present at increased levels in inflamed gingiva and to localize its expression in gingival biopsies from individuals with chronic periodontitis. METHODS: Tissues obtained during therapeutic procedures from inflamed and control sites of 9 patients were subjected to protein extraction, descriptive histology by hematoxylin and eosin, or immunohistochemistry assays. Quantification was calculated with an enzyme-linked immunosorbent assay (ELISA) kit specific for PDGF-AB. For the immunolocalization, anti-PDGF-A and -B antibodies were employed. RESULTS: PDGF concentration in the total protein extract was approximately 3 times higher in the inflamed sites (0.60 +/- 0.18 ng/mg versus 0.20 +/- 0.05 ng/mg; P = 0.03). Immunohistochemistry revealed prominent expression of PDGF in the pocket epithelial cells as well as the adjacent connective tissue. In contrast, little or no expression was detected in control biopsies devoid of the pocket epithelium and granulation tissue. CONCLUSIONS: PDGF is present in increased levels in the human inflamed gingiva and is mainly localized to the pocket epithelium. It is possible that chronic expression of PDGF contributes to the inflammatory changes that occur during periodontal diseases.

Systemic antimicrobials adjunctive to a repeated mechanical and antiseptic therapy for aggressive periodontitis: a 6-month randomized controlled trial.

BACKGROUND: The purpose of this study is to compare the additional benefit of systemic antimicrobials versus placebos to a repeated mechanical instrumentation combined with comprehensive local chemical plaque control for the periodontal treatment of generalized aggressive periodontitis (GAgP). METHODS: This was a 6-month randomized, double-masked, placebo-controlled clinical trial. All GAgP patients received full-mouth disinfection followed by staged scaling and root planing without (placebo group; n = 17) or with (test group; n = 18) systemic antimicrobials (500 mg amoxicillin [AMX] + 250 mg metronidazole [MET]; three times a day for 10 days). Clinical parameters were measured at baseline and 3 and 6 months post-therapy. Significant differences between groups at baseline were sought by using the Mann-Whitney U test, whereas comparisons over time were examined by using a general linear model repeated measures procedure. RESULTS: Both groups demonstrated similar improvements in most parameters over time. The test group presented a greater mean probing depth (PD) reduction and clinical attachment level (CAL) gain at sites with initially moderate PD at 6 months (P <0.03). No differences were seen between groups regarding mean reductions and mean gains, respectively, for PD and CAL initially ≥7 mm. The test group presented a higher percentage of sites that improved ≥2 mm and ended up with PD ≤4 mm or a lower percentage of sites that worsened ≥2 mm and remained with PD >4 mm at 3 months (P <0.01). No differences were noticed between groups for these parameters at 6 months. CONCLUSION: AMX + MET brought additional clinical effects to the repeated mechanical and antiseptic treatment of GAgP in a very short time (3 months), which tended to fade away over time (6 months).

Long-term evaluation of the antimicrobial susceptibility and microbial profile of subgingival biofilms in individuals with aggressive periodontitis

This study evaluates the antimicrobial susceptibility and composition of subgingival biofilms in generalized aggressive periodontitis (GAP) patients treated using mechanical/antimicrobial therapies, including chlorhexidine (CHX), amoxicillin (AMX) and metronidazole (MET). GAP patients allocated to the placebo (C, n = 15) or test group (T, n = 16) received full-mouth disinfection with CHX, scaling and root planning, and systemic AMX (500 mg)/MET (250 mg) or placebos. Subgingival plaque samples were obtained at baseline, 3, 6, 9 and 12 months post-therapy from 3–4 periodontal pockets, and the samples were pooled and cultivated under anaerobic conditions. The minimum inhibitory concentrations (MICs) of AMX, MET and CHX were assessed using the microdilution method. Bacterial species present in the cultivated biofilm were identified by checkerboard DNA-DNA hybridization. At baseline, no differences in the MICs between groups were observed for the 3 antimicrobials. In the T group, significant increases in the MICs of CHX (p < 0.05) and AMX (p < 0.01) were detected during the first 3 months; however, the MIC of MET decreased at 12 months (p < 0.05). For several species, the MICs significantly changed over time in both groups, i.e., Streptococci MICs tended to increase, while for several periodontal pathogens, the MICs diminished. A transitory increase in the MIC of the subgingival biofilm to AMX and CHX was observed in GAP patients treated using enhanced mechanical therapy with topical CHX and systemic AMX/MET. Both protocols presented limited effects on the cultivable subgingival microbiota.