Electrochemical mineralization of iron-tannate stain on HAp and bovine enamel-A non-peroxide approach.

Prolonged treatments for the destaining of teeth using high concentrations of hydrogen peroxide may cause secondary unwanted effects such as tooth hypersensitivity and gingival irritation. Hence, it is aimed to develop a non-peroxide-based method to oxidize iron-tannate (Fe-TA) stained hydroxyapatite (HAp) and bovine enamel (BE) samples. Constant current electrolysis (CCE) experiments were carried out on Pt working electrode in aqueous NaCl, KCl and KI solutions at discrete concentrations under continuous experiment and a non-continuous experiment. CCE shows that in the presence of iron tannate (Fe-TA) stained HAP, approximately 30 ppm of iodine was generated using 0.1M KI and nearly 40 ppm was produced with 0.2 M KI. By using a non-continuous CCE process, the lowest amount of chlorine was generated from NaCl solution, which was well within the safety limits for oral applications. Depending on the experimental conditions used, between 13 ppm and 124 ppm of chlorine was generated. CCE of Fe-TA stained on HAp using KCl reveals that at the lowest current density of 10 mA/cm2, the amount of hypochlorite generated was 20 ppm on Pt electrode having a surface area of 6 cm2. Ion chromatographic (IC) analysis revealed that non-continuous CCE of Fe-TA-BE in NaCl generated a low concentration of sodium perchlorate (0.8 ppm), whereas the continuous process generated no perchlorate, but a considerable higher quantity of chlorate for Fe-TA-BE (37 ppm) and Fe-TA-HAp (140 ppm) samples.

The effect of a toothpaste containing oleanolic acid in reducing plaque and gingivitis: a proof-of-concept randomized trial.

OBJECTIVES: To assess the safety and efficacy of an oleanolic acid (OA)-containing toothpaste in reducing gingival inflammation and plaque in patients with gingivitis. METHODS: This proof-of-concept parallel, double-blind, randomized controlled clinical trial included 99 patients. Following a 1-week washout, patients were randomized into three groups: OA group (fluoride toothpaste containing 0.1% OA and placebo mouthwash); negative control (fluoride toothpaste and placebo mouthwash); and CHX group (fluoride toothpaste and 0.12% chlorhexidine mouthwash). Patients were clinically assessed at inclusion, pre-washout visit, baseline and after 4 days, 1 week and 2 weeks of twice-daily use of the products. Patients received a diary for documentation of bleeding on brushing and provided unstimulated saliva samples. RESULTS: After two weeks, all groups showed significant reductions in all clinical parameters. The CHX group exhibited significantly greater reductions in gingival index and interproximal gingival index scores at week 2, as compared to patients in the negative control (p = 0.04). In contrast, reductions in gingival index scores did not differ between CHX and OA groups and between OA and negative control groups at week 2. The CHX group had significantly greater reductions in plaque index scores at day-4, 1-week and 2-week evaluations, as compared to the negative control and OA groups. The frequency of adverse events was similar among the groups. None of the groups reduced salivary transferrin levels. Finally, the OA group had the lowest percentage of self-reported bleeding events. CONCLUSION: OA toothpaste failed to provide antiplaque and antigingivitis effects superior to those of a fluoride toothpaste after 2 weeks of use.

Antiplaque and antigingivitis efficacy of cetylpyridinium chloride with zinc lactate compared with essential oil mouthrinses: Randomized clinical trial.

BACKGROUND: The authors of this study aimed to evaluate the clinical antiplaque and antigingivitis effects of 3 oral hygiene regimens: toothbrushing with standard fluoride toothpaste and manual toothbrush and using a mouthrinse containing cetylpyridinium chloride, zinc lactate, and fluoride (CPC + Zn + F) in an alcohol-free base; toothbrushing with standard fluoride toothpaste and manual toothbrush and using a mouthrinse containing essential oils (EO) in an alcohol-free base; and toothbrushing with manual toothbrush and standard fluoride toothpaste and manual toothbrush (control). METHODS: The participants (N = 120) were randomly assigned to study groups and followed the assigned regimens twice daily for 6 weeks. The participants were examined by a calibrated examiner for the Quigley-Hein plaque index (Turesky modification) and Löe-Silness gingival index at baseline, week 4, and week 6. Statistical analyses were performed separately for plaque and gingival indexes by means of analysis of variance, paired t test, and analysis of covariance (α = 0.05). RESULTS: At week 4, the CPC + Zn + F group presented additional reductions in dental plaque compared with EO and control groups of (21.4% [P < .001] and 31.4% [P < .001], respectively). After 6 weeks, these values were 26.7% (P < .001) and 44.8% (P < .001), respectively. For Löe-Silness gingival index, additional reduction in the CPC + Zn + F group compared with EO were 10.6% (P < .001) and 13.7% (P < .001) at 4 and 6 weeks, respectively. Compared with control, these reductions were 13.6% (P < .001) and 17.8% (P < .001), respectively. CONCLUSIONS: The regimen including a mouthrinse containing CPC + Zn + F presented higher antiplaque and antigingivitis effects than EO and control regimens. PRACTICAL IMPLICATIONS: A mouthrinse containing CPC + Zn + F is an effective protocol for the control of dental plaque and gingivitis.

A noninvasive imaging and measurement using optical coherence tomography angiography for the assessment of gingiva: An in vivo study.

Gingiva is the soft tissue that surrounds and protects the teeth. Healthy gingiva provides an effective barrier to periodontal insults to deeper tissue, thus is an important indicator to a patient's periodontal health. Current methods in assessing gingival tissue health, including visual observation and physical examination with probing on the gingiva, are qualitative and subjective. They may become cumbersome when more complex cases are involved, such as variations in gingival biotypes where feature and thickness of the gingiva are considered. A noninvasive imaging technique providing depth-resolved structural and vascular information is necessary for an improved assessment of gingival tissue and more accurate diagnosis of periodontal status. We propose a three-dimensional (3D) imaging technique, optical coherence tomography (OCT), to perform in situ imaging on human gingiva. Ten volunteers (five male, five female, age 25-35) were recruited; and the labial gingival tissues of upper incisors were scanned using the combined use of state-of-the-art swept-source OCT and OCT angiography (OCTA). Information was collected describing the 3D tissue microstructure and capillary vasculature of the gingiva within a penetration depth of up to 2 mm. Results indicate significant structural and vascular differences between the two extreme gingival biotypes (ie, thick and thin gingiva), and demonstrate special features of vascular arrangement and characteristics in gingival inflammation. Within the limit of this study, the OCT/OCTA technique is feasible in quantifying different attributes of gingival biotypes and the severity of gingival inflammation.

Synthesis and structural determination of a hexanuclear zirconium glycine compound formed in aqueous solution.

Single crystals of a zirconium-glycine compound have been first grown in aqueous solution via an excess acid and extra stabilizer approach. The crystal structure [Zr 6(OH (-)) 8(H 2O) 8(HGly) 4(Gly (-)) 4].(SO 4 (2-)) 6.14H 2O ( CP-1) has been characterized by single-crystal X-ray diffraction. The structure revealed that it is composed of hexa-zirconium octahedral clusters coordinated by eight carboxylic acid groups of glycine. The charge assignment is also consistent with the electronic structure calculations, and the computational result reveals that the Zr 6 core should have no skeleton electrons.