Publications by authors named "Samira Niemeyer"

Introduction: The aim of the study was to investigate the caries-preventive effect of fluoride-free toothpastes, containing either herbal agents or (nano-)hydroxyapatite.

Methods: Bovine dentin specimens each having a sound (ST) and a demineralized area (DT) were prepared and randomly allocated to eleven groups (n = 187). Treatments during pH cycling (28 days; 6 × 120 min demineralization/day) were brushing 2×/day with 0 ppm F- [NaF0], 500 ppm F- [NaF500], 1,100 ppm F- [NaF1100], grape seed extract [GSE], (nano-)hydroxyapatite, melaleuca oil [MO1, MO2, MO-CU], and propolis + myrrh [PM1, PM2] containing dentifrices.

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An animal model was applied to develop erosive tooth wear (ETW) and to evaluate the efficacy and safety of titanium tetrafluoride (TiF) in preventing ETW. Forty-eight male Wistar rats were divided into three groups (n = 16): TiF (2.45% F), NaF (2.

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This study evaluated the effect of actives present in conventional and desensitizing mouth rinses on the control of dentin erosive tooth wear. Two hundred and seventy dentin specimens from human molars were prepared. The specimens were randomly allocated into 10 experimental groups (n=10): 4 corresponding to desensitizing mouth rinses, 4 to conventional mouth rinses, a negative control group (C-: distilled water), and a positive control group (C+: 500 ppm fluoride plus 800 ppm tin mouth rinse).

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Erosive Tooth Wear (ETW) is the loss of tooth structure without bacterial involvement. As the resulting loss of tooth structure is irreversible, an early evaluation of the multifactorial etiology, accurate diagnosis and regular follow-up are essential. The ETW is dynamic and its progression should be continuously monitored.

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Objectives: With increasing life expectancy and improved preventive measures, teeth are retained longer, leading to a rise in prevalence of root caries lesions (RCL). However, little is known about how dentists manage this condition. The present survey aimed to evaluate the knowledge of Swiss dentists on decision making and management of RCL.

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Objectives: To assess the effect of different tin-containing toothpastes on the control of erosive tooth wear in enamel and dentin.

Methods: Enamel and dentin slabs were randomly distributed into 7 experimental groups (n = 10/substrate): C-: negative control (Artificial saliva); AmF (regular fluoridated toothpaste without tin); Sn-1 (SnF/NaF); Sn-2 (SnF/NaF/SnCl); Sn-3 (SnCl/NaF); Sn-4 (SnF/SnCl); Sn-5 (SnCl/AmF/NaF/chitosan). Specimens were submitted to 5-day erosion-abrasion cycling.

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Objectives: Despite the increase in the root caries prevalence, little is still known about how dentists manage this condition. The present study aimed to evaluate the knowledge of dentists on diagnosing and recording root caries lesions (RCL).

Methods: The survey consisted of three domains: (1) dentists' knowledge on diagnosing, recording and managing RCL; (2) information about their current general clinical routines; and (3) their demographics.

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The aim of this study was to evaluate the effect of film-forming polymer solutions of different concentrations and pH values, either associated or not with sodium fluoride (F; 225 ppm F-), when applied during the initial stage of salivary pellicle formation, to prevent the dissolution of hydroxyapatite (HA), which was determined by the pH-stat method. Polyacrylic acid (PA), chitosan, sodium linear polyphosphate (LPP), polyvinyl methyl ether/maleic anhydride (PVM/MA), and propylene glycol alginate (PGA) were tested in three concentrations (lower, medium, and higher), two pH values (native or adjusted), and either associated or not with F. Distilled water, F, and stannous ion+fluoride (Sn/F; 225 ppm F- and 800 ppm Sn2+, as SnCl2) solutions were the controls, totalizing 63 groups.

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Background: Polyphenols interact with salivary proteins and thus can improve the pellicle's erosion protective properties. This effect could be exploited to create rinsing solutions with polyphenols as active ingredients for erosion prevention. Different from the current gold standard for erosion protective rinsing solutions, these rinses would not rely on stannous ions.

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In contrast to pellicles formed in vivo, pellicles formed in vitro provide little to no erosion protection for enamel, possibly due to protein degradation from proteases during pellicle formation. With the objective to achieve a more similar effect as observed for in vivo pellicles, the effects of adding protease inhibitors (PI) to saliva in vitro, and/or exchanging saliva repeatedly during pellicle formation were investigated in a cyclic model of pellicle formation and erosion with human enamel specimens. We repeatedly assessed surface microhardness (SMH), measured initial and final surface reflection intensity (SRI), and determined calcium released during erosion.

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Objectives: To verify the protective effect of plant extracts associated with fluoride against dental erosion of dentine, in the presence and absence of a salivary pellicle.

Methods: Dentine specimens (n = 270) were randomly distributed into 9 experimental groups (n = 30/group): GT (green tea extract); BE (blueberry extract); GSE (grape seed extract); NaF (sodium fluoride); GT+NaF (green tea extract and NaF); BE+NaF (blueberry extract and NaF); GSE+NaF (grape seed extract and NaF); negative control (deionized water); and a positive control (commercialized mouthrinse containing stannous and fluoride). Each group was further divided into two subgroups (n = 15), according to the presence (P) or absence (NP) of salivary pellicle.

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To investigate the effect of some polyphenol-rich plant extracts on the protection of dentine against demineralization, both acting on the dentine and on the salivary pellicle. Dentine specimens (n = 180) were randomly distributed into 6 experimental groups (n = 30/group): Control (deionized water), Açaí extract, Blueberry extract, Green tea extract, Grape seed extract, and Sn/F (mouthrinse containing stannous and fluoride). Each group was further divided into two subgroups (n = 15), according to the site of action of the substance: on the dentine surface (D) or on the salivary pellicle (P).

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Objective: To investigate the influence of different toothbrushing (with dentifrice) protocols on the progression of erosive tooth wear for in vitro studies.

Design: Bovine enamel specimens were randomly distributed into 12 experimental groups (n = 10), according to the study factors: (1) brushing movement (horizontal or circular); (2) slurry diluent (artificial saliva or distilled water); (3) toothpaste dilution ratio (1:2, 1:3 or 1:4). A 5-day erosion-abrasion cycling model was performed, each consisting of 4 erosive challenges (0.

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Objectives: This study evaluated the protective impact of acquired enamel pellicle (AEP) engineering with statherin-derived peptide (StatpSpS), considering different AEP formation times.

Design: A total of 120 native human enamel specimens were divided into 2 main groups: 1) No AEP engineering and 2) AEP engineering with StatpSpS (pretreatment for 1 min; 37 °C, under agitation). Each group was further divided into 4 subgroups: No pellicle, or 1, 60-and-120 min AEP formation times (human saliva; 37 °C).

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Objectives: The prevalence of root caries is increasing globally, especially in the elderly population, and even though the number of patients with root caries lesions is augmenting, there are still many discrepancies in how dentists manage this condition. The present study aimed to develop and validate a questionnaire to evaluate how dentists diagnose, record and manage root caries lesions, and to verify the validity and reliability of this questionnaire.

Materials And Methods: An expert panel developed a self-administered questionnaire survey with three domains: (1) dentists' knowledge on diagnosis, recording, and managing root caries; (2) information about their current general clinical routines; (3) their demographics.

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Polyphenol-rich solutions, such as plant extracts and teas, can modify the salivary pellicle and improve the protection against dental erosion. In this study, we further explored how these polyphenol-rich plant extracts solutions behave in the presence of fluoride. We distributed enamel specimens into 9 groups (n = 15): Control_No_F- (Deionized water); Control_F- (500 ppm F-), Grape_Seed_No_F- (Grape seed extract), Grape_Seed_F- (Grape seed extract + 500 ppm F-), Grapefruit_Seed_No_F- (Grapefruit seed extract), Grapefruit_Seed_F- (Grapefruit seed extract + 500 ppm F-), Blueberry_No_F- (Blueberry extract), Blueberry_F- (Blueberry extract + 500 ppm F-), and Sn2+/F-_Rinse (commercial solution containing 800 ppm Sn2+ and 500 ppm F-).

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Objective: To evaluate the impact of desensitizing toothpastes (D), their whitening versions (DW) and whitening toothpastes (W) on tooth color change.

Methods: Tooth specimens were allocated into 11 groups (n = 10): 1. Artificial saliva (control); 2.

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This study evaluated the combination of a sugarcane cystatin (CaneCPI-5) and sodium fluoride (NaF) in acquired pellicle engineering for the prevention of dental erosion in vitro. Seventy-five human enamel specimens were prepared and divided into 5 treatment groups (n = 15/group): Deionized water (Control); Elmex™ (SnCl2/NaF/AmF); 0.1 mg/mL CaneCPI-5; 500 ppm NaF; and CaneCPI-5+NaF (Combination).

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Objectives: To assess the effect of activated charcoal toothpastes on enamel and dentin erosive wear.

Methods: Ninety enamel and dentin slabs were randomly distributed into 9 experimental groups (n = 10/substrate): Artificial saliva (negative control); Elmex Caries (EXC - 1400 ppm F as AmF, reference toothpaste without charcoal); Colgate Luminous White Activated Charcoal (CLW - 1000 ppm F as MFP); Colgate Natural Extracts (CNE - 1450 ppm F- as NaF); Oral-B 3D White Mineral Clean (OMC - 1100 ppm F as NaF); Curaprox Black is White (CBW - 950 ppm F as MFP); Bianco Carbon (BIC - no F); Natural Suavetex (NSX - no F); Oralgen Nupearl Advanced (ONA - no F). Specimens were submitted to a 5-day erosion-toothbrushing abrasion cycling.

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Objective: This study investigated the mechanism of action of different proteins/peptides (separately or in combination), focusing on how they act directly on the native enamel surface and on modifying the salivary pellicle.

Methods: A total of 170 native human enamel specimens were prepared and submitted to different treatments (2 h; 37 °C): with deionized water, CaneCPI-5, Hemoglobin, Statherin, or a combination of all three proteins/peptides. The groups were subdivided into treatment acting on the enamel surface (NoP - absence of salivary pellicle), and treatment modifying the salivary pellicle (P).

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Objective: To investigate the modification of the salivary pellicle with different polyphenol-rich teas and natural extracts for the protection against dental erosion.

Methods: We performed two experiments: one with teas (Green tea, Black tea, Peppermint tea, Rosehip tea, negative control [NC]) and other with natural extracts (Grape seed, Grapefruit seed, Cranberry, Propolis, NC), where NC was deionized water. A total of 150 enamel specimens were used (n = 15/group).

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This study investigated the potential of red wine in modulating dental erosion kinetics in the presence or absence of salivary pellicle. Polished human enamel specimens were used in two conditions; presence or absence of acquired enamel pellicle; and subdivided according to exposure: red wine, orange juice, apple juice, or citric acid. The specimens were incubated in clarified whole human saliva (presence of acquired enamel pellicle) or in a humid chamber (absence of acquired enamel pellicle) for 2 h at 37°C, then in the test substances for 1 min, at 25°C, under shaking.

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The aim of this study was to evaluate the protective effect of propylene glycol alginate (PGA) associated with sodium fluoride (NaF) against enamel erosion and erosion-abrasion. A 4-phase, split-mouth, double-blind, crossover in situ trial was conducted with the following solutions: F + PGA (225 ppm F- + 0.1% PGA), F (225 ppm F-), F + Sn (225 ppm F- + SnCl2, 800 ppm Sn2+), and negative control (distilled water).

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Objective: To evaluate the impact of the application of a F/Sn-containing mouthrinse before or after toothbrushing with a F/Sn/chitosan toothpaste on the progression of erosion/abrasion on enamel and dentin.

Methods: This crossover in situ study had five arms: Control (toothbrushing without toothpaste), Brushing (toothbrushing with toothpaste), Brushing + Rinsing, Rinsing + Brushing, and Rinsing (without toothbrushing). Fifteen subjects used removable mandibular appliances containing 3 enamel and 3 dentin specimens, which were subjected to erosion-abrasion cycling of 60 min salivary pellicle formation followed by 5 min extra-oral erosion with 1% citric acid (4x/day for 5 days).

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