Michele Paolantonio

Site-specific Subgingival Colonization by Actinobacillus actinomycetemcomitans in Orthodontic Patients.

A high prevalence of Actinobacillus actinomycetemcomitans (Aa) in subgingival plaque in patients for orthodontia already has been observed. The present study had the following aims: 1) to ascertain a direct relationship between the orthodontic appliance placement and the subgingival colonization by Aa, and 2) to determine whether the Aa growth specifically occurred on teeth with braces attached or whether the presence of orthodontic appliances could also cause the isolation of Aa in teeth free from therapeutic appliances. Twenty-four young systemically and periodontally healthy subjects with malaligned and crowded teeth in the anterior sextants of both dental arches participated in this study. After 1 session of ultrasonic scaling with oral hygiene instructions during the first experimental session, the mesiobuccal sites of the first molars and the distobuccal sites of the lateral incisors in both dental arches in each participant were subjected to clinical and microbiologic examination for the recovery of Aa. Clinical examination consisted of recording the presence of plaque and the examination of gingival bleeding on probing and probing depth. Microbiologic sampling was obtained with the insertion of 3 sterile paper points at the deepest part of each gingival sulcus. Altogether, 192 periodontal sites were examined. After the examinations, the patients received fixed orthodontic appliances in only 1 dental arch (test sites) and the other one was left free from appliances (control sites). Clinical examination and microbiologic sampling were repeated in the same experimental test and control sites after 4, 8, and 12 weeks. At the 12-week session, the orthodontic appliance was removed from the test arch, and, 4 weeks later, a further clinical and microbiologic examination was performed. The results showed that, during the period with orthodontic appliances, the presence of plaque scores and the gingival bleeding on probing scores were increased significantly and that Aa, initially absent from all but 1 subject, was isolated in 19 and 20 subjects after 4 and 8 weeks, respectively. Furthermore, no gingival sites from the control teeth (free from Aa colonization at baseline) showed positive results for the sought-after bacterium throughout the entire length of the study. It was concluded that the placement of orthodontic appliances promotes the subgingival growth of Aa; this specific microbial change is specifically restricted to subgingival plaque from orthodontic appliance-bearing teeth. The presence of orthodontic bands and brackets therefore cannot affect the microbiologic condition of the whole mouth.

Residual aluminum oxide on the surface of titanium implants has no effect on osseointegration

The cleanliness of titanium dental implants surfaces is considered to be an important requirement for achieving osseointegration, and it has been hypothesized that the presence of inorganic contaminants could lead to lack of clinical success. Aluminum ions are suspected to impair bone formation by a possible competitive action to calcium. The objective of the present study was to describe the effects of residual aluminum oxide particles on the implant surface on the integration of titanium dental implants as compared to decontaminated implants in a rabbit experimental model. Threaded screw-shaped machined grade 3 c.p. titanium dental implants, produced with high-precision equipment, were used in this study. The implants were sandblasted with 100-120 microm Al2O3 particles at a 5atm pressure for 1min, then 24 implants (control implants) underwent ASTM F 86-68 decontamination process in an ultrasonic bath. The other 24 implants (test implants) were washed in saline solution for 15min. Both test and control implants were air-dried and sterilized at 120 degrees C for 30min. After sterilization the implants were inserted into the tibiae (two test and two control implants in each rabbit). Twelve New Zealand white mature male rabbits were used in this study. The protocol of the study was approved by the Ethical Committee of our University. No complications or deaths occurred in the postoperative period. All animals were euthanized, with an overdose of intravenous pentobarbital, after 4 weeks. A total of 48 implants were retrieved. The images were analyzed for quantitation of percentage of surface covered by inorganic particles, bone-implant contact, multinucleated cells or osteoclasts in contact with the implant surface and multinucleated cells or osteoclasts found 3mm from the implant surface. The differences in the percentages between the two groups have been evaluated with the analysis of variance. The implant surface covered by inorganic particles on test implants was significantly higher than that of control implants (p=0.0000). No statistically significant differences were found in the bone-implant contact percentages of test and control implants (p=0.377). No statistically significant differences were found in the number of multinucleated cells and osteoclasts in contact with the implant surface (p=0.304), and at a distance of 3mm from the implant surface (p=0.362). In conclusion, our histological results do not provide evidence to support the hypothesis that residual aluminum oxide particles on the implant surface could affect the osseointegration of titanium dental implants.

Clinical, microbiologic, and biochemical effects of subgingival administration of a xanthan-based chlorhexidine gel in the treatment of periodontitis: a randomized multicenter trial.

BACKGROUND The use of locally delivered antibacterials containing chlorhexidine (CHX) was proposed to improve the effectiveness of non-surgical periodontal treatment. The present multicenter randomized study investigated the effects of a xanthan-based chlorhexidine (Xan-CHX) gel used as an adjunct to scaling and root planing (SRP) in the treatment of chronic periodontitis. METHODS Ninety-eight systemically healthy subjects with moderate to advanced periodontitis were recruited in four centers (59 females and 39 males; aged 24 to 58 years). For each subject, two experimental sites located in two symmetric quadrants were chosen with probing depths (PD) >or=5 mm and positive for bleeding on probing (BOP). These two sites were randomized at the split-mouth level with one receiving a single SRP treatment and the other receiving a single SRP + Xan-CHX gel treatment. Supragingival plaque, modified gingival index, PD, clinical attachment level (CAL), and BOP were evaluated at baseline (prior to any treatment) and after 3 and 6 months. At the same times, subgingival microbiologic samples and gingival crevicular fluid (GCF) were collected for the analysis of total bacterial counts (TBCs), including the identification of eight putative periodontopathogens, and alkaline phosphatase (ALP) activity, respectively. RESULTS The Xan-CHX treatment group showed greater improvements compared to the SRP group for PD and CAL at 3 and 6 months (P <0.001). The differences in PD reduction between the treatments were 0.87 and 0.83 mm at 3 and 6 months, respectively (P <0.001); for CAL, these were 0.94 and 0.90 mm, respectively (P <0.001). Similar behavior was seen when the subgroup of pockets >or=7 mm was considered. The percentage of sites positive for BOP was similar between the treatments at each time point. For the comparisons between the treatment groups, no differences were seen in the TBCs and GCF ALP activity at baseline and 6 months; in contrast, slightly, but significantly, lower scores were recorded for the Xan-CHX treatment group at 3 months (P = 0.018 and P = 0.045, respectively). Moreover, greater reductions in the percentages of sites positive for the eight putative periodontopathic bacteria were generally seen for the Xan-CHX treatment group compared to SRP alone. CONCLUSIONS The adjunctive use of Xan-CHX gel promoted greater PD reductions and CAL gains compared to SRP alone. These results were concomitant with better microbiologic and biochemical outcomes when Xan-CHX gel use was added to SRP, particularly up to 3 months after treatment.

Systemic inflammation following non-surgical and surgical periodontal therapy

AIM To describe the kinetics of serum inflammatory markers after a course of treatment comprising surgical and non-surgical treatment of chronic periodontitis (CP). MATERIAL AND METHODS Fourteen CP cases received full-mouth non-surgical treatment and, after 6 months, at least two surgical sessions. Blood samples were collected at various time-points after treatment. Blood markers of systemic inflammation/coagulation including leucocyte counts, C-reactive protein (CRP), serum amyloid-A (SAA) and D-dimers and renal function (cystatin C) were determined using high-sensitivity assays. RESULTS Periodontal treatment resulted in substantial reductions of the number of pockets, gingival bleeding and plaque at 3 and 6 months after non-surgical therapy (p<0.001). Surgical therapy led to an additional reduction of periodontal pockets (p<0.01). Marked increases in the serum levels of CRP and SAA were noted 24 h after non-surgical therapy (p<0.01) and periodontal surgeries (p<0.05). D-dimer levels increased drastically 24 h after non-surgical therapy (p<0.05). The drastic increase of CRP after non-surgical therapy was greater than both the surgical therapy sessions (p<0.05). CONCLUSIONS Patients undergoing periodontal treatment experience perturbations of systemic inflammation of a greater magnitude after non-surgical than surgical periodontal therapy.

Bone formation inside the material interstices of e-PTFE membranes: a light microscopical and histochemical study in man.

Membranes used in guided bone regeneration (GBR) should possibly achieve a good degree of tissue integration with neighbouring connective tissues in order to obtain a mechanically stable environment necessary for successful bone and soft tissue healing. The authors observed, in a histological study of e-PTFE membranes used for GBR and retrieved from 10 patients, inside the material interstices of the membranes, in many cases the presence of connective tissue cells and collagen fibres, and in two cases the presence of bone. The presence, inside the membrane, of connective tissue and bone could help toward a tight integration between the membrane and neighbouring tissues, with the production of a biological seal.

Enamel Matrix Derivative, Alone or Associated With a Synthetic Bone Substitute, in the Treatment of 1- to 2-Wall Periodontal Defects

BACKGROUND In this study, we compare the effects of enamel matrix derivative (EMD) associated with a hydroxyapatite and β-tricalcium phosphate (HA/β-TCP) implant to EMD alone and to open-flap debridement (OFD) when surgically treating 1- to 2-wall intrabony defects. METHODS Thirty-four patients, exhibiting ≥3 intraosseous defects in different quadrants, were each treated by OFD, EMD, or EMD + HA/β-TCP in each defect. At baseline and 12 and 24 months, a complete clinical and radiographic examination was done. Pre-therapy and post-therapy clinical (probing depth [PD], clinical attachment level [CAL], and gingival recession [GR]) and radiographic (defect bone level [DBL] and radiographic bone gain [RBG]) parameters for the different treatments were compared. RESULTS After 12 and 24 months, almost all the clinical and radiographic parameters showed significant changes from baseline within each group (P <0.001). Differences in PD, CAL, and DBL scores were also seen among the three groups at the 12- and 24-month visits (P <0.001). At 12 and 24 months after treatment, the EMD + HA/β-TCP group showed significantly greater PD reduction (4.00 ± 0.42 mm; 4.25 ± 0.63 mm), CAL gain (3.47 ± 0.65 mm; 3.63 ± 0.91 mm), and RBG (3.17 ± 0.69 mm; 3.35 ± 0.80 mm) and less GR increase (0.56 ± 0.37 mm; 0.63 ± 0.42 mm) compared with the OFD and EMD groups (P <0.05). CONCLUSION Our data support the hypothesis that the adjunct of an HA/β-TCP composite implant with EMD may improve the clinical and radiographic outcomes of the surgical treatment of unfavorable intrabony defects.

The secretome of periodontal ligament stem cells from MS patients protects against EAE

Manipulation of stem cells or stem cells-derived secretome has emerged as a novel alternative therapeutic option for multiple sclerosis (MS). Here we show that human periodontal ligament stem cells (hPDLSCs)-derived conditioned medium (hPDLSCs-CM) and purified exosomes/microvesicles (hPDLSCs-EMVs) obtained from Relapsing Remitting (RR)-MS patients and healthy donors block experimental autoimmune encephalomyelitis (EAE), a mouse model of MS, by inducing anti-inflammatory and immunosuppressive effects in spinal cord and spleen, and reverse disease progression by restoring tissue integrity via remyelination in the spinal cord. We show that hPDLSCs-CM and hPDLSCs-EMVs reduce pro-inflammatory cytokines IL-17, IFN-γ, IL-1β, IL-6, TNF-α, and induce anti-inflammatory IL-10. In addition, apoptosis related STAT1, p53, Caspase 3, and Bax expressions were attenuated. Our findings unravel the immunosuppressive effects of hPDLSCs-CM and hPDLSCs-EMVs in EAE mice, and suggest simple alternative autologous source for patient-customized cell-free targeting treatment in MS patients.

Autogenous Periosteal Barrier Membranes and Bone Grafts in the Treatment of Periodontal Intrabony Defects of Single‐Rooted Teeth: A 12‐Month Reentry Randomized Controlled Clinical Trial

BACKGROUND This randomized clinical trial compares the outcomes of combination treatment by autogenous periosteal membranes and bone graft versus guided tissue regeneration (GTR) with collagen membranes or open-flap debridement (OFD) only in the treatment of intraosseous defects. METHODS Forty-two patients affected by moderate to severe chronic periodontitis were enrolled. Each patient had one deep intrabony defect (≥6 mm). They were randomly assigned into three groups: patients treated with 1) an OFD procedure alone (OFD group); 2) a GTR procedure with collagen membranes (GTR group); and 3) a combined treatment procedure by autogenous periosteal membranes and autogenous bone chips (aCPRT group). Clinical and intrasurgical examinations including probing depth (PD), clinical attachment level (CAL), gingival recession (GR), and defect bone level (DBL) were performed at baseline and after 1 year. RESULTS After 1 year, all of the evaluated clinical parameters showed statistically significant changes from baseline within each group (P <0.01). The GTR and aCPRT groups had significantly greater PD reductions (5.2 and 4.4 mm, respectively) and CAL (3.2 and 3.9 mm) and DBL gains (2.4 and 3.1 mm) compared to the OFD group (PD, 2.9 mm; CAL, 1.6 mm; DBL, 1.5 mm); moreover, the aCPRT group showed a significantly smaller GR increase (0.5 mm) and a greater DBL gain (3.1 mm) compared to the GTR group (2 and 2.4 mm, respectively; P <0.05). CONCLUSIONS Both the GTR and aCPRT treatments produce additional clinical benefits over OFD alone. Moreover, the aCPRT technique can minimize post-surgical GR and produce better defect bone-level improvement.

Bevacizumab-related osteneocrosis of the jaw.

We describe a case of jaw bone necrosis after a lung adenocarcinoma bone metastasis, treated the first time in 2004 by means of pneumonectomy and lymph node ablation. One week after a dental extraction, the patient experienced pain in the mandibular region, in conjunction with alveolar bone exposure. Treatment with amoxicillin and clavulanate every 12 hours for 15 days and 0.2% chlorhexidine rinses was administered and there was a remission of infective complications, but not the closure of the exposed alveolar bone. Only at this time did the patient refer that he was treated with bevacizumab therapy immediately after the extraction. A preventive dental assessment of patients scheduled for bevacizumab therapy should be useful as for the zoledronic acid therapy. Dental surgery procedures for patients during bevacizumab therapy should be carefully evaluated and considered as the last choice, to reduce all possible risks and prevent complications.

Could early rheumatoid arthritis resolve after periodontitis treatment only?: case report and review of the literature.

AbstractRheumatoid arthritis (RA) is an immune-mediated polyarthritis; currently no pathogenic agent has been identified as a disease trigger. A patient with RA, presumably caused by periodontal infection, whose remission has been observed after periodontitis treatment in absence of specific RA therapy, is reported here for the first time, to our knowledge.A 61-year-old male patient presented migrant arthritis associated with antibodies against citrullinated protein antigens positivity. The clinical features allowed to make RA diagnosis according to the 2010 European League against Rheumatism/American College of Rheumatology RA classification criteria. X-ray of the second upper molar showed chronic apical periodontitis. After its treatment, arthritis remission has been observed in the absence of specific RA therapy.It has been suggested that periodontitis may have a trigger role in RA pathogenesis. This could be explained by the enzymatic action of Porphyromonas gingivalis, probably leading to break tolerance to collagen. The identification and subsequent treatment of periodontitis should therefore be considered pivotal in RA prophylaxis and management.