LDH-Based Voltammetric Sensors.

Layered double hydroxides (LDHs), also named hydrotalcite-like compounds, are anionic clays with a lamellar structure which have been extensively used in the last two decades as electrode modifiers for the design of electrochemical sensors. These materials can be classified into LDHs containing or not containing redox-active centers. In the former case, a transition metal cation undergoing a reversible redox reaction within a proper potential window is present in the layers, and, therefore, it can act as electron transfer mediator, and electrocatalyze the oxidation of an analyte for which the required overpotential is too high. In the latter case, a negatively charged species acting as a redox mediator can be introduced into the interlayer spaces after exchanging the anion coming from the synthesis, and, again, the material can display electrocatalytic properties. Alternatively, due to the large specific surface area of LDHs, molecules with electroactivity can be adsorbed on their surface. In this review, the most significant electroanalytical applications of LDHs as electrode modifiers for the development of voltammetric sensors are presented, grouping them based on the two types of materials.

Interdental plaque reduction after the use of different devices in patients with periodontitis and interdental recession: A randomized clinical trial.

OBJECTIVES: To determine the efficacy of four different oral hygiene protocols involving adjunctive interdental devices in terms of plaque and bleeding scores in periodontitis-affected patients. MATERIAL AND METHODS: This was a randomized clinical trial with a 5-week follow-up, including previously treated periodontitis patients not undergoing any supportive care. Patients were randomly allocated to 4 groups: manual toothbrush (group TB); toothbrush plus dental floss (group TB/F); toothbrush plus interdental brushes (group TB/IDB) and toothbrush plus rubber interdental picks (group TB/RIDB). Oral hygiene instructions (OHI) were provided at baseline (T-7) and at T0 (1-week) then bi-weekly (T14/T28). At T0, supragingival professional cleaning was delivered. Plaque and bleeding indexes were taken at all timepoints by a single calibrated examiner, blind to group allocation. RESULTS: At T-7, patients were comparable for age, body mass index (BMI) and all clinical parameters, exceptions for the Interdental Angulated Bleeding Index. At T28, significant reductions of plaque and gingival inflammation were noted in all groups (p < 0.001) and within the expected ranges. Intergroup comparisons identified that group TB/IDB and group TB/RIDB achieved lower levels of plaque and inflammation than group TB (p < 0.05). Group TB/IDB and group TB/RIDB showed lower levels of plaque and lower inflammation as measured by angulated bleeding index than group TB/RIDB (p < 0.05). CONCLUSION: Interdental brushes and rubber interdental picks were more efficient than toothbrushing alone and toothbrushing and floss in reducing plaque and gingival inflammation measured in a periodontitis-affected population.

Periodontitis in Italian patients with established rheumatoid arthritis: A cross-sectional study.

OBJECTIVE: To assess the prevalence and severity of periodontitis (P) among Italian patients affected by rheumatoid arthritis (RA). MATERIALS AND METHODS: A full-mouth periodontal examination and a rheumatologic examination were performed. RA disease activity was scored using the DAS28. Serum analyses investigated levels of rheumatoid factor, anti-citrullinated protein antibodies (ACPAs), C-reactive protein, erythrocyte sedimentation rate and fibrinogen. Information concerning smoking, body mass index and RA medical therapy was collected. Data were analysed by Student's t test, chi-square test, binary logistic regression and Spearman's rank. RESULTS: This cross-sectional study included 120 subjects, 77 had both diseases while 43 only had RA. The number of teeth present was statistically lower in the RA-P compared to the RA group (p < .05). There were statistically more subjects seropositive for ACPAs in the RA-P group (62.3% vs. 32.6%, p < .05). RA-P patients had an adjusted OR = 2.9 of presenting a moderate-severe DAS28 score (DAS28 ≥ 3.2). CONCLUSIONS: Higher prevalence of severe P was noted among RA subjects. The clinical severity of RA was strongly correlated with the clinical periodontal parameters, and RA subjects also affected by P had an OR of 2.9 for presenting with a moderate-severe RA (DAS28 score ≥ 3.2).

Dental plaque, gingival inflammation and tooth -discolouration with different commercial -formulations of 0.2% chlorhexidine rinse: a double-blind randomised controlled clinical trial.

PURPOSE: To investigate the efficacy of various formulations of chlorhexidine 0.2% (CHX) in terms of plaque and gingival bleeding control compared to each other and to saline rinse (CTRL) over a 35-day rinsing period. MATERIALS AND METHODS: Seventy subjects were randomly allocated to one of 4 groups rinsing twice daily for 35 days. The different groups used CHX 0.2% rinse with alcohol (CHX1) and without alcohol (CHX2), with an antidiscolouration system (CHX3) or saline rinse (CTRL). Clinical examinations to evaluate full-mouth plaque scores (FMPS) and periodontal parameters were performed at baseline, 7, 21 and 35 days. Tooth discolouration (TD) was measured at each time point using digital photographs and spectrophotometric analysis. RESULTS: At 35 days, CTRL showed the highest levels of plaque. The mean changes in FMPS from baseline were 69.8% ± 6.8 for CHX1, 57.5% ± 9.8 for CHX2, 43.7% ± 9.8 for CHX3 and 25.8% ± 7.7 for CTRL. Statistically significant differences were demonstrated between CHX1 and CHX3 (p = 0.02), CHX2 vs CHX3 (p ≤ 0.05) and CHX1/CHX2 vs CHX3 (p < 0.05). In contrast, CHX3 appeared more effective in reducing inflammatory indexes. TD increased over time in 60% to 70% of participants, although lighter staining was found in the CHX3 group. Greater FMPS reduction was observed in participants with staining vs without staining (26.0% ± 12.3, p = 0.04). CONCLUSION: Conventional CHX appeared more effective in terms of plaque reduction. Interestingly, the newest formulation showed a higher control of gingival inflammation. Staining was associated with lower plaque levels.

Cyclooxygenase-2 induction after oral surgery does not entirely account for analgesia after selective blockade of cyclooxygenase 2 in the preoperative period.

BACKGROUND: The administration of selective cyclooxygenase-2 inhibitors before surgery is regarded as an innovative option to manage postoperative pain. This study was designed to (1) examine the efficacy of preoperative cyclooxygenase-2 blockade on postoperative oral pain and (2) compare pain intensity with prostaglandin E2 (PGE2) production and cyclooxygenase isoform (cyclooxygenase-1, cyclooxygenase-2) messenger RNA (mRNA) expression at the surgical site during the postoperative period. METHODS: Sixty patients with impacted lower third molars were randomly allocated to three single-dose treatment groups--placebo, 50 mg rofecoxib, or 550 mg naproxen--1 h before extraction. Pain intensity was evaluated with categorical and visual analog scales every 30 min from 90 to 240 min after surgery. At these times, PGE2 production in the alveolar socket was also evaluated. Cyclooxygenase-1 and cyclooxygenase-2 mRNA expression was examined by reverse-transcription polymerase chain reaction in gingival specimens collected during tooth removal and 240 min after surgery. RESULTS: Pain intensity and PGE2 production in the placebo group increased throughout the observation period. Naproxen prevented pain and decreased PGE2 release at all time points. Rofecoxib reduced PGE2 production versus placebo from 150 min onward, while inducing analgesia through the whole observation period. mRNA assay in gingival specimens collected at tooth extraction revealed cyclooxygenase-1 expression, whereas cyclooxygenase 2 was undetectable. At the end of observation, cyclooxygenase-1 mRNA expression was unchanged, whereas cyclooxygenase-2 mRNA was significantly induced. CONCLUSIONS: This study indicates that preoperative administration of a selective cyclooxygenase-2 inhibitor ensures effective control of postoperative pain. It is suggested that the selective blockade of inducible cyclooxygenase 2 at the surgical site does not entirely account for the analgesic action occurring in the postoperative period.

Maxillary sinus augmentation with platelet-rich plasma and fibrinogen cryoprecipitate: a tomographic pilot study.

The purpose of this study was to evaluate the clinical efficacy of platelet-rich plasma, autologous bone, and autologous fibrinogen as cryoprecipitate in maxillary sinus augmentation procedures. Six patients (age range, 29-58) undergoing sinus augmentation procedures were included in the study. Platelet-rich plasma and autologous fibrinogen in the form of cryoprecipitate were prepared from 300 ml of blood. Sinus augmentation was performed with intraoral bone grafts, platelet-rich plasma, and cryoprecipitate. The amount of regeneration was then evaluated quantitatively and qualitatively with Spiral TC (Dentascan) pre- and postoperatively 6 months after the intervention. Orthopantomography was performed preoperatively 3 and 6 months after the surgery. A mean platelet concentration of 320.5% was obtained from the baseline platelet blood count. The tomographic analysis indicated an average bone augmentation of 6.27 mm (range, 3.5-10 mm). Radiologically, a satisfactory morphological recovery of the maxillary jaw was obtained. No graft resorption was noticed. Orthopantomography indicated mineralization as early as 3 months postoperatively in the entire study population. This technique appeared to be safe and effective. Our preliminary results encourage the clinical use of platelet-rich plasma associated with cryoprecipitate.