In Vitro Evaluation of Structural Factors Favouring Bacterial Adhesion on Orthodontic Adhesive Resins.

Bacterial adhesion to the surface of orthodontic materials is an important step in the formation and proliferation of plaque bacteria, which is responsible for enamel demineralization and periodontium pathologies. With the intent of investigating if adhesive resins used for bracket bonding are prone to bacteria colonization, the surface roughness of these materials has been analyzed, combining information with a novel methodology to observe the internal structures of orthodontic composites. Scanning electron microscopy, combined with focus ion bean micromachining and stylus profilometry analyses, were performed to evaluate the compositional factors that can influence specific pivotal properties facilitating the adhesion of bacteria to the surface, such as surface roughness and robustness of three orthodontic adhesive composite resins. To confirm these findings, contact angle measurements and bacteria incubation on resin slide have been performed, evaluating similarities and differences in the final achievement. In particular, the morphological features that determine an increase in the resins surface wettability and influence the bacterial adhesion are the subject of speculation. Finally, the focused ion beam technique has been proposed as a valuable tool to combine information coming from surface roughness with specific the internal structures of the polymers.

SEM characterization and ageing analysis on two generation of invisible aligners.

BACKGROUND: The purpose of the in vitro study is to investigate and compare the morphological features and the chemical stability in weight of two different polyurethane-based blends, Smart Track (LD30) and Exceed30 (EX30), used for orthodontic aligners manufacture before and after the oral usage. METHODS: Twenty orthodontic aligners were randomly selected: 10 LD30 and 10 EX30, each group was divided in two subgroups, never used and intra-orally aged. By the employment of a Stereomicroscope, a section of 5 × 5 mm was cut from the buccal surface of the incisal region of each aligner. All samples were subjected to Scanning Electron Microscopy and Ageing tests in different solutions to simulate the hostility of the oral environment. The statistical method used was t-test. RESULTS: At SEM images, LD30 appears more homogeneous in texture respect to EX30. However, after clinical usage, both materials show significant structural alterations: findings have been supported by higher magnifications at SEM, by which it is clearly to observe many superficial cracks cross through the polymer structures of LD30U, absent in never used samples. LD30U surface becomes also smoother due to the disappearance of most of the conglomerates, but at the same time also rougher while EX30U shows a greater irregularity and porosity in which large and deep cracks are also highlighted. Although these changes occur persistently, in the aging tests no significant weight loss from both materials has been found, confirming the initial hypothesis of a good chemical stability and safety of both polyurethane mixtures even in conditions of severe hostility. CONCLUSION: LD30 is the expression of the technological evolution of EX30, this is made evident above all by its morphological architecture, more homogeneous and defined but also by the chemical stability that can be appreciated even in evident critic situations.

Far Infrared Technology (FIT) Therapy Patches, Protects from Inflammation, Oxidative Stress and Promotes Cellular Vitality.

BACKGROUND: It is known from the most recent literature that far-infrared (FIR) radiations promote a broad spectrum of therapeutic benefits for cells and tissues. OBJECTIVE: To identify molecular mechanisms by which FIT patches, as a far infrared technology, protects against damage caused by inflammatory process and oxidative stress. METHODS: Endothelial cells (HUVEC, Human Umbilical Vein Endothelial Cells) were used as in vitro experimental model. HUVEC were stimulated with a pro-inflammatory cytokine, TNF-α, or hydrogen peroxide (H2O2) to induce oxidative stress. As markers of inflammation were evaluated: VCAM1 (Vascular Cell Adhesion Molecule 1), ICAM1 (Intercellular Adhesion Molecule 1) and E-Selectin by Western Blot analysis. Oxidative stress was assessed by cytofluorimetric analysis. The experiments were performed on control cells (no patch) or in cells treated with the FIT infrared technology applied on the basis of the culture plate. RESULTS: HUVEC stimulated with TNF-α and treated with FIT patches had significant reduction of the expression of VCAM1, ICAM1 and E-Selectin (p<0.05). HUVEC stimulated with H2O2 and treated with FIT patches were significantly protected from oxidative stress (p <0.01) when compared to control cells. We measured cell viability and proliferation in HUVEC and HEK-293 (Human embryonic kidney cells) cells by MTT assay. HEK-293 and HUVEC treated with FIT patches showed a significantly higher percentage of basal vitality compared to control cells (p<0.0001 for HEK-293, p<0.05 for HUVEC). CONCLUSION: FIT therapy patches - infrared technology, through these protective mechanisms, could be used in all pathologies where an increase in inflammation, oxidative stress and degenerative state are present.

The Effectiveness of Chlorhexidine and Air Polishing System in the Treatment of Candida albicans Infected Dental Implants: An Experimental In Vitro Study.

Background: Peri-implantitis is an inflammatory disease with an increasing diffusion rate which can affect the long-term survival of a prosthetic rehabilitation. The present study focused on the decontaminating efficacy of chlorhexidine and air polishing system with sodium bicarbonate powder against Candida albicans, a microorganism which seems to have a superinfecting opportunistic role in the pathology. The aim of the authors was to investigate and compare the effectiveness of these treatments, commonly used in clinical practice. Methods: An in vitro study was conducted to analyze the effects of two widely used therapeutic aids for the disinfection of affected titanium implants: chlorhexidine (CHX) and air polishing with sodium bicarbonate powder (P). A qualitative and quantitative comparative analysis of the residual biofilm was carried out using a colorimetric assay (XTT) and scanning electron microscopy (SEM) observation. The experiment was conducted both on machined titanium surfaces and on rough sandblasted ones with the aim of bringing out differences in the therapeutic outcomes concerning the superficial texture of the implant. The null hypothesis was that no difference could be detected between the samples, regarding both the treatments performed and the nano-structural features of titanium. Results: The best results (on both types of implant surfaces) were obtained when combining the use of chlorhexidine and air polishing (C + P). A linear decrease in the optical density (OD) values recorded at three different time points (30 s, 1 min, 5 min) was also observed passing from the first to the last one. When observed under scanning electron microscope rough surfaces showed an extensive and highly structured biofilm, more complex if compared to the one encountered when analyzing machined implants. Conclusions: the present pilot study showed that rough surfaces can promote fungal adhesion and eventually hinder the outcome of a decontaminating treatment. For this purpose, the physio-chemical technique is always more efficient if compared to a single-technique approach regardless of the surface characteristics.

Age-Dependent Levels of Protein Kinase Cs in Brain: Reduction of Endogenous Mechanisms of Neuroprotection.

Neurodegenerative diseases are among the leading causes of mortality and disability worldwide. However, current therapeutic approaches have failed to reach significant results in their prevention and cure. Protein Kinase Cs (PKCs) are kinases involved in the pathophysiology of neurodegenerative diseases, such as Alzheimer's Disease (AD) and cerebral ischemia. Specifically ε, δ, and γPKC are associated with the endogenous mechanism of protection referred to as ischemic preconditioning (IPC). Existing modulators of PKCs, in particular of εPKC, such as ψεReceptor for Activated C-Kinase (ψεRACK) and Resveratrol, have been proposed as a potential therapeutic strategy for cerebrovascular and cognitive diseases. PKCs change in expression during aging, which likely suggests their association with IPC-induced reduction against ischemia and increase of neuronal loss occurring in senescent brain. This review describes the link between PKCs and cerebrovascular and cognitive disorders, and proposes PKCs modulators as innovative candidates for their treatment. We report original data showing εPKC reduction in levels and activity in the hippocampus of old compared to young rats and a reduction in the levels of δPKC and γPKC in old hippocampus, without a change in their activity. These data, integrated with other findings discussed in this review, demonstrate that PKCs modulators may have potential to restore age-related reduction of endogenous mechanisms of protection against neurodegeneration.

Influence of mandibular third molar surgical extraction on the periodontal status of adjacent second molars.

BACKGROUND: The periodontal health distal of second molars (M2) is often compromised because of third molar (M3) impactions. The aim of this study was to evaluate healing and periodontal status of mandibular M2 after M3 surgical extraction. METHODS: Eighty-nine consecutive patients with 89 asymptomatic M3 who needed surgical extraction of one fully- or semi-impacted M3 entered this study. Clinical measurements, probing pocket depth (PPD), clinical attachment level (CAL), plaque index (PI), gingival index (GI), and bleeding on probing (BOP), were compared for M2 at baseline (T0) and 6-months (T1) postsurgical extraction. Multiple logistic regression analysis assessed different risk factors for postoperative changes of periodontal parameters. RESULTS: Six-month M2 PPD improved at disto-vestibular (T0-5.2/T1-3.0 mm) and disto-lingual (T0-5.4/T1-3.2 mm) sites. The average attachment gains at T1 were 1.9 and 2 mm, respectively (P < 0.05). BOP, PI, and GI showed significant clinical improvements after extractions. Fifty-three out of 72 (73.6%) M2 presenting a PPD ≥ 4mm at baseline healed at 6 months recall without periodontal pockets. Older age (mean 55 years, SD 16.7; range 26 to 81) and mean distal PPD at baseline of 7 mm was more likely to be associated with PPD ≥ 4 mm 6 months postextraction (P < 0.05). Past history of periodontitis patients were 41 times more likely to present PPD ≥ 4 mm after healing (OR = 41.4; 95% CI = 10.9 to 156.5, P < 0.05). CONCLUSION: Mandibular M3 extractions seem to improve overall periodontal health distal of M2. History of periodontitis, preoperative deep pockets and older age are independent risk factors for poorer healing and residual pockets after M3 surgical extraction.

Orthodontic Fixed Appliance and Periodontal Status: An Updated Systematic Review.

BACKGROUND: Periodontal implications of orthodontic therapy are frequent, gingival and periodontal conditions need to be evaluated for every appointment. Several studies have analyzed the effects of fixed appliance on periodontal health. OBJECTIVE: To evaluate whether there is updated scientific evidence on the relationship between fixed orthodontic therapy and periodontal health. METHODS: A literature search was performed using the Pubmed and Cochrane databases and manual search; the search was carried out using the keywords "orthodontic" and "periodontal". Articles published only in the English language from January 1997 to April 2017 were included. The inclusion criteria were: RCTs, cohort studies, cross-sectional studies and case-control studies only in English language; only studies on humans, with a minimum sample size of 20 patients and no restriction in terms of patient ages; orthodontic fixed appliances placed into the buccal tooth surface; standardization and training in oral hygiene; Periodontal Index (PI), Gingival Index (GI), Bleeding on Probing (BOP), Pocket Probing Depth (PPD), at least at baseline (before appliance was placed) and after follow up (with a minimum period of 3 months). The exclusion criteria were as follows: absence of baseline data before fixed appliances was placed; patients with systemic diseases, periodontal disease or craniofacial anomalies; removable appliances or orthodontic appliance on the lingual dental surface; and no standardization or training in oral hygiene.Studies were selected by abstract and title; then, inclusion and exclusion criteria were applied. The studies that satisfied the inclusion criteria were evaluated and classified as having low, moderate or high methodology quality. RESULTS: Fifty-five records were reviewed on the basis of title and abstract. After full-text reading, 47 full texts were excluded, and 3 articles were classified as having low methodological quality and 5 as having moderate methodological quality. CONCLUSIONS: The present systematic analysis suggests that there is moderate scientific evidence that a fixed appliance influences periodontal status; no article reported a high score.

Perspectives on multisensory perception disruption in idiopathic environmental intolerance: a systematic review.

PURPOSE: Multiple chemical sensitivity (MCS) also known as idiopathic environmental intolerance/illness (IEI) encompasses a cohort of subjective symptoms characterized by susceptibility to a wide spectrum of environmental compounds, causing symptoms involving various organs and a decrease in quality of life. The aim of this systematic review is to summarize evidence about MCS, with focus on indexed studies analyzing sensory pathway-related disorders. METHODS: Medical databases were searched for English language articles related to the topic, published between 1965 and 2017 in academic, peer-reviewed journals. Particular focus was concentrated on articles depicting disturbances involving sensory organs. References of the relevant articles were examined to identify additional significant documents. RESULTS: Fifty-eight studies were eligible for full text review. Of these, 34 studies met the selection criteria and were included in this analysis. Many variables, such as different diagnostic criteria, lack of homogeneous symptom questionnaires and the general incidence of personality traits in control subjects, biased studies as confounding factors. However, moderate evidences show that sensory pathways are somewhat altered, especially with respect to information processing in the limbic system and related cortical areas. Recent studies suggested the presence, in MCS cohorts, of attention bias, sensitization and limbic kindling, as well as recently revealed subclinical organic alterations along sensory pathways. CONCLUSIONS: Evidences are consistent with MCS/IEI to be the result of a neural altered processing of sensorial ascending pathways, which combined with peculiar personality traits constitutes the underpinning of a multisensory condition needing multidisciplinary clinical approach.

Micro-computed tomography evaluation of microleakage of Class II composite restorations: An in vitro study.

OBJECTIVE: The aim of this study is to investigate the microleakage attained with three resin-based material used to restore deep Class II cavities. A null hypothesis was chosen: there is no difference in microleakage among the tested materials. MATERIALS AND METHODS: A total of 30 Class II cavities were prepared in freshly extracted molars with the proximal mesial and distal margins located, respectively, 1.5 mm apically and 1.5 mm coronally to the cementum-enamel junction. Restorations were completed using a three-step enamel-dentin adhesive system "Etch and Rinse," margins were relocated using a micro-hybrid, preheated, or flowable composite and restorations were then completed using a conventional composite. All samples were coated with nail varnish with the exception of an area along the margins and apex was sealed using epoxide cement and then thermocycled (30-s dwell time, 5°C/55°C, 1000 cycles). A 50% ammoniac AgNO3 solution was used as tracer according to Tay's protocol. The microleakage analysis was performed using a microtomography system Sky-scan 1072 (SKYSCAN, Kartuizersweg 3B 2550, Konitch, Belgium). RESULTS: The mean microleakage of all the tested materials showed greater leakage in the cementum margins; flowable composite exhibit greater leakage among the groups. Significant differences (P < 5%) within groups in both enamel and dentin margins were present. None of the tested materials eliminated marginal microleakage. Preheated composite showed significantly lesser microleakage. CONCLUSION: Tested materials showed statistical differences in microleakage; thus, the null hypothesis has been rejected. Within the limitations of the present experimental procedure, it can be concluded that flowable resin composite should be avoided at the dentin/cementum margin.

Mechanical properties of "two generations" of teeth aligners: Change analysis during oral permanence.

Aim of this in vitro study was to analyze structural properties of two different polymeric orthodontic aligners, Exceed30 (EX30) and Smart Track (LD30), before and after use. Forty patterns of aligners were randomly selected: 20 LD30 and 20 EX30, worn intra-orally for 14±3 days, 22 h/day. From each aligner, 10 specimens were prepared from buccal surfaces of the incisor region by the cutting of samples 5×5 mm under a stereomicroscope. All samples were subjected to Fourier transform infrared spectroscopy, micro-Raman spectroscopy, X-ray diffraction, tensile and indentation strength test. LD30 appeared more homogeneous, with a crystalline fraction lower than EX30 and exhibited a higher elastic behavior and a lower tendency to warp after use than EX30. LD30 demonstrated better adaptability to the dental arch and greater consistency of application of orthodontic forces than produced with EX30. However, both materials showed structural modifications that resulted in increased sample hardness and hyper-plasticity.

Management of Single Uncomplicated Dental Extractions and Postoperative Bleeding Evaluation in Patients With Factor V Deficiency: A Local Antihemorrhagic Approach.

PURPOSE: The aim of the present study was to analyze the management of single dental extractions and postoperative bleeding in patients with a diagnosis of factor V deficiency. A careful evaluation of each case will allow the team to categorize the risk and operate safely, minimizing the incidence of intraoperative and postoperative complications. If necessary, the oral-maxillofacial surgeon can choose to do so in collaboration with the hematologist on a case-by-case basis. PATIENTS AND METHODS: The present retrospective study included 5 patients with mild congenital factor V deficiency who had undergone at least 1 dental extraction. Mouth rinse with tranexamic acid, nonresorbable sutures, and gelatin sponge packed in the alveolar socket were used to obtain hemostasis. No systemic therapies, such as fresh frozen plasma, platelet concentrate, or recombinant activated factor VII, were administered. RESULTS: Twenty-five teeth were extracted. The factor V plasma levels ranged from 14.1 to 22.4%. Local antihemorrhagic treatments resulted in good hemostasis. No hemorrhagic complications or intraoperative or postoperative major bleeding was observed. CONCLUSIONS: Dental extractions appear to be safe procedures for patients with mild factor V deficiency when a bleeding risk assessment has been performed in conjunction with a hematologist and an appropriate treatment protocol is followed. Our treatment protocol was found to be effective and well tolerated by all the patients.

Orofacial signs and dental abnormalities in patients with Mulvihill-Smith syndrome: A literature review on this rare progeroid pathology.

BACKGROUND: Mulvihill-Smith syndrome is a rare sporadic condition that was first recognized in 1975. A total of 11 cases have been described in the literature. The aim of this study was to describe the orofacial signs and dental anomalies, their frequency, and the relationship between Mulvihill-Smith syndrome and other progeroid syndromes via a review of the literature. METHODS: A systematic PubMed search was performed to retrieve articles published between 1975 and the present day that described patients affected by Mulvihill-Smith syndrome. The search identified 14 articles, and data on 11 patients were extracted from the selected articles. RESULTS: A total of 7 patients (63.6%) affected by Mulvihill-Smith syndrome were described as having a typical "bird" face. Dental abnormalities, including irregular shape, enamel defects, hypodontia, and taurodontism, were described in 6 patients (54.5%). All patients (100%) had multiple pigmented nevi on the face and a lack or thinning of subcutaneous tissue around the neck and face. Three patients with Mulvihill-Smith syndrome exhibited early onset of tumors of the gastrointestinal tract, including the tongue. CONCLUSION: Mulvihill-Smith syndrome is a clinically complex disease that may be caused by a single gene mutation. Numerous different tissues of the body are affected. This analysis of the orofacial signs may help clinicians to diagnose this rare pathology.

Management of Surgical Third Lower Molar Extraction and Postoperative Progress in Patients With Factor VII Deficiency: A Clinical Protocol and Focus on This Rare Pathologic Entity.

PURPOSE: The purpose of the present study was to analyze the management of surgical third molar extraction and postoperative progress in patients with a diagnosis of factor VII deficiency. Close collaboration between the oral-maxillofacial surgeon and hematologist will allow the team to categorize the risk and operate safely, thereby minimizing the incidence and severity of intraoperative and postoperative complications. MATERIALS AND METHODS: The present retrospective study included 7 patients with factor VII deficiency who had undergone third lower molar surgery. Their factor VII deficiency ranged from 10.5 to 21.0%. Recombinant activated factor VII (rFVIIa) (coagulation factor VIIa [recombinant]; NovoSeven RT; Novo Nordisk, Bagsvaerd, Denmark) was transfused intravenously in a single dose of 25 µg/kg body weight, 30 minutes before surgical extractions. After the surgery, betamethasone, an analgesic, and an ice pack were administered. RESULTS: Pretreatment with recombinant activated factor VII resulted in excellent hemostasis. No hemorrhagic complications and no postoperative major bleeding were observed. CONCLUSIONS: The extraction of the third lower molar appears to be a safe procedure for patients with factor VII deficiency when appropriate prophylaxis with rFVIIa is used.

Autogenous Tooth Fragment Adhesive Reattachment for a Complicated Crown Root Fracture: Two Interdisciplinary Case Reports.

Trauma of anterior teeth is quite a common occurrence in both children and adults. Various degrees of trauma leading to fracture may affect teeth in different ways depending on the age of the patient and extent of fracture and other factors that will be discussed. Guidelines have been given as to how each of these situations should be treated. In the past, often more aggressive restorations were performed to restore fractured teeth. However improved and more efficient adhesion may affect the type of treatment we decide to carry out, leading to more conservative therapies through an increased preservation of tooth structures.

Genotypic and phenotypic heterogeneity in Streptococcus mutans isolated from diabetic patients in Rome, Italy.

Our study focuses on the antimicrobial susceptibility, genotypic and phenotypic heterogeneity, and serotype classification of the Streptococcus mutans isolated from type II diabetic patients (n = 25; age 42-68). Eighty-two percent of isolates were classified as serotype c. No serotype k was present. Macrorestriction analysis of genomic DNA of the isolates exhibited a clonal diversity that paralleled the phenotypic heterogeneity, which was also assessed in terms of biofilm forming ability. Isolates were susceptible to all the classes of antibiotics. In conclusion a great heterogeneity and no antimicrobial resistance were apparent in the considered S. mutans strains from diabetic patients.

Immediate Nonfunctional Loading of Two Single-Maxillary Postextractive Implants: 6-Year Postloading Results of Two Case Reports.

Objectives. The aim of the study was to evaluate and compare crestal bone loss of single-maxillary immediate postextractive implants and immediate nonfunctional loading (INFL) during 72 months of follow-up. Material and Methods. Two single titanium implants (Certain Prevail, Biomet 3I, USA) were placed in two patients using INFL technique. Implant stability and crestal bone level were measured on periapical radiographs at 1, 3, and 6 months after surgery. Results. All osseointegrated implants were clinically successful after 6 years of functional loading. Conclusion. Within the limit of the present case report, the paper supports the concept that INFL of single dental implant can be a successful treatment procedure.

Saliva improves Streptococcus mitis protective effect on human gingival fibroblasts in presence of 2-hydroxyethyl-methacrylate.

This study aimed to investigate the effect of saliva on Streptococcus mitis free cells and on S. mitis/human gingival fibroblasts (HGFs) co-culture model, in presence of 2-hydroxyethyl-methacrylate (HEMA). The bacterial aggregation both in the planktonic phase and on HGFs, as well as the apoptotic and necrotic eukaryotic cells amount were analyzed, in presence of saliva and/or HEMA. The aggregation test revealed a significant saliva aggregation effect on S. mitis strains compared to the untreated sample. No significant differences were recorded in the amount of culturable bacteria in all studied conditions; however, from microscopy images, the saliva/HEMA combining effect induced a significant bacterial aggregation and adhesion on HGFs. HEMA treatment decreased viable eukaryotic cell number with a parallel increment of necrotic cells, but when saliva was added to the co-culture, the viable cells percentage increased to a value comparable to the control sample.

ElectroBond improves immediate dentin microtensile bond strength of two etch-and-rinse adhesives.

PURPOSE: The aim of this study was to investigate whether an electrical device for dental adhesive application (ElectroBond) influences bonding of two-step etch-and-rinse adhesives. MATERIALS AND METHODS: Human teeth were selected and cut perpendicularly to their long axis to expose middle/ deep dentin. Specimens were then longitudinally sectioned into halves (experimental and control halves) to create two similar bonding substrates. Experimental halves were bonded using an ElectroBond-assisted application, while control halves were bonded with disposable sponges. The adhesives tested were Adper Scotchbond 1XT and XP-BOND. Bonded specimens were submitted to the microtensile bond strength test. Additional adhesive interfaces were prepared and processed for nanoleakage investigation involving TEM examination. RESULTS: The microtensile bond test revealed higher values (p < 0.05) for both adhesives if ElectroBond was used during layering (55.5 +/- 7.9 MPa for Adper Scotchbond 1XT and 54.7 +/- 7.1 MPa for XP-BOND) compared to the conventional mechanical adhesive application technique (41.1 +/- 6.1 MPa for Adper Scotchbond 1XT and 38.0 +/- 7.8 MPa for XP-BOND). No difference between the two adhesives was found under the same application conditions. With electricity-assisted application, TEM micrographs revealed a significant decrease in nanoleakage expression compared to the controls. CONCLUSION: The use of an electric current produced by ElectroBond during the application of two-step etch-and-rinse adhesives may enhance resin impregnation, thus improving dentin hybridization. Further studies should be done to confirm that this device can similarly improve adhesive application in vivo.

Effects of thermocycling and use of ElectroBond on microtensile strength and nanoleakage using commercial one-step self-etch adhesives.

The aim of this study was to determine the effect of thermocycling and the use of an electronically assisted application technique on the microtensile bond strength and nanoleakage of bonded interfaces created using one-step self-etch adhesives. Composite build-ups were bonded coronally to sectioned human molars using XENO III or Clearfil S(3)Bond. Adhesives were applied following the manufacturers' instructions (control) or with the aid of an electrical application device (ElectroBond). Teeth were sectioned into non-trimmed bonded beams for microtensile testing. Half of the specimens were subjected to 20,000 thermocycles, and the controls were not thermocycled. All specimens were tested to failure and peak stress was calculated. Additional specimens were prepared for nanoleakage analysis using transmission electron microscopy (TEM). The immediate bond strength of both adhesives increased as a result of using the ElectroBond device (XENO III 38.9 +/- 8.1 MPa; Clearfil S(3)Bond 46.2 +/- 9.9 MPa) compared with no use of the device (XENO III 26.7 +/- 7.8 MPa; Clearfil S(3)Bond 38.9 +/- 8.1 MPa). Thermocycling significantly decreased the bond strength of XENO III (27.1 +/- 7.9 MPa with the use of ElectroBond; 20.7 +/- 9.2 MPa without the use of ElectroBond); however, thermocycling did not affect the Clearfil S(3)Bond strength (47.2 +/- 8.6 MPa with the use of ElectroBond; 33.6 +/- 8.3 MPa without the use of ElectroBond). Reduced nanoleakage was found for both resins as a result of the use of the ElectroBond device, with or without thermocycling. Application of one-step, self-etch adhesives with the ElectroBond device significantly increased microtensile bond strength and reduced nanoleakage, but the effect of thermocycling was found to be brand-dependent.

Neurotrophins and their receptors in human lingual tonsil: an immunohistochemical analysis.

Lymphoid organs are supplied by many nerve endings associated with different kinds of cells and macrophages. The role of this innervation on the release of locally active molecules is still unclear. Lingual tonsils belong to Waldeyer's Ring, in close association with palatine tonsils and nasopharyngeal (adenoids) tonsils, thus constituting part of NALT (nasal-associated lymphoid tissue) together with the tubal tonsils and lateral pharyngeal bands. In this study, we focused our attention on the expression of some neurotrophins (NTs) and their high- and low-affinity receptors in human lingual tonsils. Light immunohistochemistry showed that human tonsillar samples were generally positive for all the NTs investigated (NGF, BDNF, NT-3, NT-4) and their receptors (TrKA, TrKB, TrKC and p75) with some different expression levels. NGF and TrKC were strongly expressed in macrophages, but weakly in lymphocytes. However, BDNF and TrKB was highly expressed in lymphocytes and weaker in macrophages. The low-affinity receptor for NGF, p75, was mainly moderately expressed in the analysed samples. These results suggest the presence of a pattern of neurotrophin innervation in the human lingual tonsil which may play a role in sustaining inflammatory conditions and in modulating a close interaction between the nervous system and the different immune cellular subtypes.