(1/53) The Ice Man's diet as reflected by the stable nitrogen and carbon isotopic composition of his hair.
Establishing the diets of ancient human populations is an integral component of most archaeological studies. Stable isotope analysis of well-preserved bone collagen is the most direct approach for a general assessment of paleodiet. However, this method has been limited by the scarcity of well-preserved skeletal materials for this type of destructive analysis. Hair is preserved in many burials, but is often overlooked as an alternative material for isotopic analysis. Here we report that the stable carbon and nitrogen isotope values for the hair of the 5200 year-old Ice Man indicates a primarily vegetarian diet, in agreement with his dental wear pattern. Whereas previous investigations have focused on bone collagen, the stable isotope composition of hair may prove to be a more reliable proxy for paleodiet reconstruction, particularly when skeletal remains are not well preserved and additional archaeological artifacts are unavailable. (+info)
(2/53) Exposure to flour dust and the level of abrasion of hard tooth tissues among the workers of flour mills.
A study of the oral health of workers in flour mills was carried out. The examined group consisted of 40 males and 8 females currently employed at flour mills. As much as 93.75% of the workers showed evidence of dental abrasion, particularly of the front teeth. The authors concluded that the dental abrasions in the group are closely related to the work environment. (+info)
(3/53) Microstructural analysis of demineralized primary enamel after in vitro toothbrushing.
The aim of this study was to investigate, in vitro, the morphological characteristics of demineralized primary enamel subjected to brushing with a dentifrice with or without fluoride. In order to do so, 32 enamel blocks were divided in 4 different groups containing 8 blocks each. They were separately immersed in artificial saliva for 15 days. The experimental groups were: C - control; E - submitted to etching with 37% phosphoric acid gel (30 s); EB - submitted to etching and brushing 3 times a day with a non-fluoridated dentifrice; EBF = submitted to etching and brushing 3 times a day with a fluoridated dentifrice. The toothbrushing force was standardized at 0.2 kgf and 15 double strokes were performed on each block. After the experimental period, the samples were prepared and examined under SEM. The control group (C) showed a smooth surface, presenting scratches caused by habitual toothbrushing. The etched samples (E) exhibited different degrees of surface disintegration, but the pattern of acid etching was predominantly the type II dissolution. The brushed surfaces were smooth, with elevations which corresponded to the exposure of Tomes' process pits and depressions which corresponded to interrod enamel. Particles resembling calcium carbonate were found in the most protected parts of the grooves. No morphological differences were observed between brushing with fluoridated (EBF) and non-fluoridated (EB) dentifrice. The results suggest that the mechanical abrasion caused by brushing demineralized enamel with dentifrice smoothes the rough etched surface, and the presence of fluoride does not cause morphological modifications in this pattern. (+info)
(4/53) Crowns and other extra-coronal restorations: resin-bonded metal restorations.
Resin-bonded metal restorations is the final part of the series. Cast metal restorations which rely on adhesion for attachment to teeth are attractive because of their potential to be much more conservative of tooth structure than conventional crowns which rely on preparation features providing macromechanical resistance and retention. (+info)
(5/53) Wear and superficial roughness of glass ionomer cements used as sealants, after simulated toothbrushing.
The purpose of this study was to evaluate, in vitro, the properties (wear and roughness) of glass ionomer cements that could influence their indication as pit and fissure sealants. The utilized materials were Fuji Plus, Ketac-Molar and Vitremer (in two different proportions: 1:1 and :1). The resin-based sealant Delton was used as control. By means of an electronic balance (precision of 10-4 g), wear was measured in function of weight loss after simulated toothbrushing. Superficial roughness was determined by means of a surface roughness-measuring apparatus. The results revealed that diluted Vitremer and Fuji Plus were less resistant to toothbrushing abrasion and had the greatest increase in superficial roughness. Although in clinical situations luting or diluted ionomer cements are often utilized as alternatives to resin-based sealants, the resultsof this study revealed that the properties of those cements are worse than those of restorative ionomers, whichpresented results similar to those of the evaluated resin sealant. (+info)
(6/53) Gingival recessions caused by lip piercing: case report.
Fear of losing the teeth is common among patients presenting with gingival recession. This report describes a case in which unusual gingival recessions were caused by lip piercing. Periodontal treatment involved removal of the causative agent, hygiene instruction, scaling and root planing, and coverage of the root with a subepithelial connective tissue graft. The therapeutic measures applied in this case yielded satisfactory root coverage, an increase in the width of the keratinized gingiva, improvement in hygiene status and absence of dental hypersensitivity. (+info)
(7/53) In vitro evaluation of human dental enamel surface roughness bleached with 35% carbamide peroxide and submitted to abrasive dentifrice brushing.
The aim of this in vitro study was to evaluate the surface roughness of human enamel bleached with 35% carbamide peroxide at different times and submitted to different superficial cleaning treatments: G1 - not brushed; G2 - brushed with fluoride abrasive dentifrice; G3 - brushed with a non-fluoride abrasive dentifrice; G4 - brushed without dentifrice. Sixty fragments of human molar teeth with 4 x 4 mm were obtained using a diamond disc. The specimens were polished with sandpaper and abrasive pastes. A perfilometer was used to measure roughness average (Ra) values of the initial surface roughness and at each 7-day-interval after the beginning of treatment. The bleaching was performed on the surface of the fragments for 1 hour a week, and the surface cleaning treatment for 3 minutes daily. The samples were stored in individual receptacles with artificial saliva. Analysis of variance and the Tukey test revealed significant differences in surface roughness values for G2 and G3, which showed an increase in roughness over time; G1 and G4 showed no significant roughness differences. The bleaching with 35% carbamide peroxide did not alter the enamel surface roughness, but when the bleaching treatment was performed combined with brushing with abrasive dentifrices, there was a significant increase in roughness values. (+info)
(8/53) Durability of FTLA treatment as a medicament for dentin hypersensitivity--abrasion resistance and profiles of fluoride release.
The purpose of this study was to evaluate the durability of tubules occluded with FTLA treatment by toothbrush abrasion test on the applied surface and by measuring fluoride release from the FTLA components. Dentin specimens with simulated hypersensitive surfaces were treated with APF containing tannic acid. After which, the specimens received lanthanum-chloride-with-powdered-fluoroapatite-glass-ceramics treatment. The specimens were subjected to toothbrush abrasion test up to 6,000 strokes. SEM observation revealed that dentinal tubules of the FTLA treated specimens were completely occluded with fine deposits even after toothbrush abrasion of 6,000 strokes. EPMA analysis revealed that fluoride, lanthanum, and aluminum were the main FTLA components on the dentin surface after 6,000-stroke abrasion. To measure fluoride release from the FTLA components, a slurry was enclosed in a cellulose tube and suspended in deionized water at 37 degrees C. After fluoride was dialyzed against deionized water, a high concentration of fluoride was found to be released from FTLA the components, indicating FTLA treatment's prominent durability. These results suggested that FTLA treatment has a superior resistance against toothbrush abrasion and a high fluoride-releasing performance. These characteristics lend much weight to showing that the FTLA method is an effective and durable medicament for dentin hypersensitivity. (+info)