PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Tooth Demineralization”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,153 records · Page 64Linked to original sources
PubMed1990

Potential dental effects of infants' fruit drinks studied in vitro.

Eighteen different infants' drinks from five manufacturers were examined for their carbohydrate, calcium, phosphorus and acid contents, and their attack on tooth mineral. Seven of the drinks were compared with nine varieties of adults' soft drinks, and demineralization was studied with and without the presence of a cariogenic oral streptococcus. The influence of the acids already in the drinks in dissolving Ca and P outstripped that of any acid generated in these studies in vitro by microbial fermentation of the sugars they contained, giving an indication of their relative erosiveness rather than their cariogenic action. Various other features of the drinks relevant to dental health were identified. Titratable acid was a better guide than pH to their dental properties. Although there were considerable differences between the various infants' drinks, taken as a group, their acidity levels and demineralizing powers were generally lower than those of the adults' drinks.

Adult↗
PubMed2000

The Early Stages of Native Enamel Dissolution Studied with Atomic Force Microscopy.

Food-induced demineralization (erosion) is one of the key factors in surface structural changes of tooth enamel, with soft drinks being a significant etiological agent. The objective of this study was to measure early stages of enamel loss with high accuracy on native enamel surfaces combined with qualitative observations of changes in the surface morphology using the atomic force microscope (AFM). Native unerupted third molar surfaces were partly covered with a gold reference layer. Samples were imaged with the AFM before dissolution (at baseline) and after exposure to three different drinks (mineral water, a "toothkind" blackcurrant drink, and a lemon and lime juice drink) at five different exposure times (15 min, 30 min, 1 h, 2 h, and 3 h). The changes in the surface morphology were investigated qualitatively as well as quantitatively. This study showed that the maximum material loss occurred at the aprismatic parts of the enamel close to the perikymata. The maximum enamel loss was greatest for the lemon and lime juice drink and lowest for water. A two-way ANOVA of the transformed data, employing the natural logarithm, showed a statistically significant difference between both the drinks and the exposure time at a 95% confidence level (P=0.000). This demonstrates that the AFM is a suitable tool for measuring early stages of enamel demineralization. Copyright 2000 Academic Press.

Journal Article↗
PubMed1997

Dental erosion, oral hygiene, and nutrition in eating disorders.

OBJECTIVE: To determine the influence of oral hygiene practices and additional fluoride on erosive tooth wear in eating disorders. The proportional dietary intake of carbohydrates, fats, and proteins was also investigated. METHOD: Tooth wear was measured with the use of the tooth wear index (TWI). All subjects completed a questionnaire on past dental history as well as a 1-week diet sheet. A total of 33 subjects participated in the study, 20 of whom were follow-ups, allowing the progress of dental erosion to be made. All subjects were referred from the Department of Clinical Psychology. RESULTS: Oral hygiene practices between subjects with and without severe erosion were not significantly different. Only 8 bulimics spent more time brushing after vomiting than at other times. The pH of vomitus from 6 subjects ranged between 2.9 and 5.0, with a mean of 3.8, well below the critical pH for enamel demineralization to occur. Of the 20 follow-up subjects, 12 (60%) exhibited worsening tooth wear. The mean values for daily carbohydrate, protein, and fat intake were not significantly different at baseline and at recall, and the proportional dietary intake was similar to recommended energy provision at 47%, 40%, and 13%, respectively. DISCUSSION: The contribution by toothbrush abrasion to the overall wear in the eroded dentition of bulimics is not significant. Therefore, immediate post-vomiting oral hygiene practices can be recommended. The proportional nutritional intake values of carbohydrates, fats, and proteins in this group of bulimics are acceptable.

Adult↗
PubMed1995

Salivary factors in caries models.

Consideration of salivary factors in caries models rarely extends beyond viewing saliva as a sink or diluent for plaque metabolic products, or as a source of buffering, for neutralizing plaque acids. In reality, saliva has a complex chemistry and a wide range of biochemical activities that may significantly affect plaque chemistry and microbiology. Thus, saliva is a major source of microbial nutrients, without which bacterial acid production is diminished. Buffering by salivary bicarbonate, and base production from urea and basic amino acids and peptides, significantly affect Stephan curves. Saliva is supersaturated with respect to basic calcium phosphate salts and contains novel inhibitors of calcium phosphate precipitation, while specific salivary proteins bind calcium. It seems important to consider if this system is reflected in plaque. Saliva, with contributions from serum and bacterial constituents, provides most of the precursors for the acquired enamel pellicle, which acts to slow demineralization during caries attack. Pellicle constituents appear to influence initial bacterial colonization of tooth surfaces and, therefore, may affect the microbial composition of plaque, but their detailed effects on plaque are poorly understood. Microbial adaptations to the anti-bacterial systems also seem important but are poorly investigated. Thus, saliva possesses an array of activities that have substantial actual or potential impact on plaque and, therefore, merit consideration for inclusion in systems intended to model dental caries.

Bacterial Adhesion↗
PubMed2001

[Dental pain].

"The extreme variability of toothache is such that a good rule for any examiner is to consider all pains about the mouth and face to be of dental origin until provide otherwise" (Welden E. Bell). Dental caries is a disease of the calcified tissues of the teeth, characterised by demineralization of the inorganic portion and destruction of the organic substance of the tooth. The acids which affects the primary decalcifications is derived from the fermentation of starches and sugar logged in the retaining centers of the teeth. Dental caries can be classified in relation with the depth of the lesions: caries of the enamel, caries of the dentin, pulp diseases which are the result of dental caries in which bacterial invasion of the dentin and pulp tissue occurs, diseases of the periapical tissues which leads to periapical cyst, or to periapical abcess.

Acute Disease↗
PubMed1996

Hard tissue of teeth and their calcium and phosphate content in Ambystoma mexicanum (Urodela: Ambystomatidae).

The wall of the pulp cavity, fracture faces and the demineralized surfaces of teeth from larvae and adults of Ambystoma mexicanum were investigated by scanning electron microscopy (SEM). Calcium and phosphate contents were determined by microanalysis. The apical part of the tooth (crown, tooth apex) contains dentin canals. In the larva, these do not reach the enamel-dentin border but end below this border in front of a denser hard substance, possibly enameloid. The pedicel in the adult and the basal portion of the tooth in the larva (base) are without dentin canals. These parts of the teeth are characterized by longitudinally arranged collagen fibres as visualized on the demineralized surfaces. These observations indicate a congruency in early-larval and adult teeth between base and pedicel as well as apex and crown. This partition is also confirmed by the calcium and phosphate values which were identical in larvae and adults. Highest values are found in enamel and lowest values in the tooth-bearing bone. Calcium and phosphate content show a clear difference between dentin and the basal part of the tooth (pedicel and base). The ring-like dividing zone in the adult tooth is less well mineralized.

Ambystoma mexicanum↗
PubMed1987

Bacterial endotoxin inhibits migration, attachment, and orientation of human gingival fibroblasts in vitro and delays collagen gel contraction.

The purpose of this study was to assess the effect of endotoxin adsorbed to dental surfaces and to collagen type I on the migration, attachment, and orientation of human gingival fibroblasts (HGF). Transversely cut porcine tooth root slices (RS), 200 micron thick, were prepared. Half of the RS obtained were partially demineralized in EDTA. Half of the demineralized and non-demineralized RS were incubated with 400 micrograms/mL of endotoxin for 24 hr, whereas the other half were maintained in PBS and served as controls. Experimental and control RS were placed on confluent layers of HFG and cultured for six days. Cell migration toward and cell attachment to the periphery of the RS and the formation of oriented cell sheets were assessed by means of photographic techniques. Additionally, six-day-old cultures were fixed and processed for SEM observation. In separate experiments, the effect of endotoxin on cell attachment to collagen type I and on contraction of three-dimensional collagen gels was assessed. It was found that: (i) bacterial endotoxin inhibited migration and attachment of HGF to both demineralized and non-demineralized cementum and interfered with the development of oriented cellular structure: (ii) the inhibitory effect was significantly more pronounced for non-demineralized than for demineralized cementum: (iii) the morphology of HGF attached to endotoxin-treated dental surfaces was altered compared with that of their controls: and (iv) bacterial endotoxin inhibited cell attachment to collagen type I and delayed the contraction of collagen gel.

Animals↗
PubMed1984

Compositional, structural, and phase changes in in vitro laser-irradiated human tooth enamel.

Tooth enamel laser irradiated under certain conditions previously has been shown to have reduced subsurface demineralization rates. Identification of these laser-induced changes has bearing on understanding the dissolution rate reduction mechanism; some of these changes, ones that occur in high temperature regions, were studied in this report. X-ray diffraction and infrared spectroscopy were used to identify changes in enamel of extracted intact human teeth subjected to high energy density (approximately 10,000 J/cm2) 10.6 microns wavelength carbon dioxide laser irradiance. The laser irradiance melted the enamel apatite; this solidified melt was composed of minor phases of alpha-tricalcium phosphate, alpha-Ca3 (PO4)2, and tetracalcium phosphate, Ca4(PO4)2O, and a major phase of modified apatite. The apatite modifications, as compared with the original were (1) reductions in contents of water, protein, carbonate, and chloride (or chloride rearrangement); (2) essentially no change in apatite hydroxide content; (3) possible incorporation of oxide replacing some hydroxide ions; and (4) an uptake of traces of carbon dioxide and cyanate. An infrared band at 434 cm-1 that appears in spectra of hydroxyapatite partially dehydroxylated by thermal treatment was assigned to oxide translation. This band was utilized to search for oxide formation in the laser-irradiated tooth enamel.

Apatites↗
PubMed1976

Histochemical localization of alkaline pyrophosphate- phosphohydrolase in tooth-forming cells of rat.

The activity of a pyrophosphate-splitting tissue factor in jaws, teeth and intestinal mucosa has been studied by means of histochemistry. Freeze-cut, unfixed sections of whole animals were incubated in a buffered medium (pH 8.6) containing inorganic pyrophosphate (PP) Pb2+, Mg2+, and Zn2+ at various concentrations. The effects of compound R 8231, heat, aldehyde fixation, and demineralization with EDTA were also investigated. In sections showing optimal staining, deposition of incubation products was found in the stratum intermedium and the subodontoblastic cells of the developing tooth, in the osteoblastic layers, and at the surface of the intestinal mucosa. The hard tissues were also stained except in the demineralized sections. Treatment with heat or compound R 8231 resulted in loss of originally observed soft tissue staining while short-time demineralization with EDTA enhanced the staining reaction. It is argued that a nonspecific deposition of the capturing ion, Pb2+, can hardly explain the observed soft tissue staining. The results point to the presence of a PP-splitting enzyme, and it is suggested that the enzyme exhibits features of an alkaline phosphatase with PP-phospholhydrolytic properties rather than of an inorganic pyrophosphatase.

Animals↗
PubMedDate not supplied

Effect of fluoride topical solutions on enamel demineralization by lactate buffers and Streptococcus mutans in vitro.

Applications of APF and NaF solutions to extracted human teeth reduced the extent of enamel subsurface demineralization induced by colonization of S. mutans but were ineffective against demineralization by acid lactate buffers. It is concluded that the CaF2 formed on the tooth surface during the treatment is responsible for the protection observed.

Acidulated Phosphate Fluoride↗
PubMed2005

Ca/P mol ratio of cries-affected dentin structures.

BACKGROUND: A new approach called "minimum intervention" has been introduced for restoration of carious lesions to preserve tooth structure. This approach suggests that perhaps caries need not always be removed completely from deeper portions of the cavity. It is, therefore, important to characterize caries-affected dentin structures, because of the potential changes in bonding quality when using different dentinal substrates. MATERIALS AND METHOD: Ninety teeth (30 teeth each group) were studied. The first group (CF) consisted of 30 caries-free teeth. The second group (CC) consisted of 30 teeth, for which caries-free dentin teeth was chemically demineralized. The third group (ND) consisted of 30 extracted human molars with coronal carious lesions. After all tooth samples were water-polished with grit #600 SiC paper, they were tested by surface contact angle measurements and the electron-probe microanalyzer to measure Ca/P mol ratio. RESULTS: Contact angles were CF = 60.07 degrees ; CC = 30.8 degrees; ND = 26.11 degrees , p<0.05. Ca/P mol ratios were as follows; CF = 1.549 (+/-0.0435); CC = 1.324 (+/-0.2305); ND = 1.568 (+/-0.0523), p<0.05. Weibull analyses for Ca/P mol ratio indicated shape parameter (m) of CF was 13.3; it was 12.8 for ND and 11.8 for CC. Above the delta point (=1.65 in Ca/P ratio), for both groups m = 3.4. CONCLUSION: Caries-affected dentin surfaces (naturally-developed and chemically created) were statistically more chemically active than caries-free dentin surface. Ca/P mol ratio of chemically created caries was less than other two groups.

Calcium↗
PubMed1983

Acid resistance of enamel exposed to fluoride-containing orthodontic cements.

In a previous study enamel fluoride uptake from fluoride-containing orthodontic cements was evaluated after a 21-day period. The enamel fluoride uptake from a zinc phosphate cement (A), a zinc phosphate cement containing 5 per cent stannous fluoride by weight (B), and a silicophosphate cement (C) was compared. The results indicated that there was a net loss of fluoride from enamel beneath the orthodontic bands cemented with A while the enamel beneath B and C acquired significant amounts of fluoride. The purpose of the present study was to evaluate enamel fluoride uptake after 12 weeks and the effect of the fluoride uptake or loss by the enamel on acid resistance. Five teeth each had bands cemented with cements A, B and C, respectively, and were individually suspended in synthetic saliva for 12 weeks at 37 degrees C. Following this period the bands were removed, the cements were carefully cleaned off the teeth, and the crowns of the teeth were individually suspended in a lactic acid buffer at pH 4 for 4 weeks. Each tooth crown was then sectioned longitudinally and examined microradiographically to study the degree of enamel demineralization. Characteristic subsurface enamel carieslike lesions were noted on all the specimens studied. The carieslike lesions in the enamel exposed to the fluoride-containing cements were considerably reduced. The enamel which had acquired fluoride from the fluoride-containing cements was apparently more resistant to artificial caries attack.

Acids↗
PubMed2004

Comparative evaluation of in-vitro effects of Brazilian green propolis and Baccharis dracunculifolia extracts on cariogenic factors of Streptococcus mutans.

Streptococcus mutans triggers dental caries establishment by two major factors: synthesis of organic acids, which demineralize dental enamel, and synthesis of glucans, which mediate the attachment of bacteria to the tooth surface. Propolis is a natural product that may prevent dental caries. Baccharis dracunculifolia DC (Asteraceae), a native plant from Brazil, is the most important botanical origin for the production of green propolis (Brazilian propolis) by honeybees. However, whether B. dracunculifolia (Bd) has an anticariogenic effect, like green propolis, remains unknown. Herein, we have made a comparative evaluation of the effects of extracts from green propolis and Bd on the glucan synthesis and acidogenic potential of S. mutans. The inhibitory effects of the extracts on bacterial acid production were evaluated through the potentiometric measurement of pH from bacterial suspensions treated with serial concentrations of both extracts. Besides presenting close inhibitory values at the same concentration range, Bd leaf rinse and green propolis extracts had similar IC(50) values (0.41 and 0.34 mg/ml, respectively). Both extracts produced a bacteriostatic effect on S. mutans cultures at a concentration of 0.40 mg/ml. Estimated inhibitory values of green propolis and Bd leaf rinse extracts on the synthesis of insoluble glucans (IC(50)=12.9 and 25.0 microg/ml, respectively) and soluble glucans (IC(50)=50.4 and 49.1 microg/ml, respectively) were not significantly different from each other at p<0.05. The results demonstrate that Bd leaf rinse and green propolis extracts have similar inhibitory effects on the S. mutans cariogenic factors evaluated herein, and allowed us to suggest that Bd leaves may be a potential source for pharmaceutical products employed for this purpose.

Anti-Infective Agents↗
PubMed2001

Regenerative therapy of furcation defect.

Furcation defects of multiple-root teeth are complications of progressive periodontal diseases. The recommended technique of regenerative therapy in furcation defects of the lower molars is implantation of hydroxylapatite or demineralized freeze-dried bone. A case of a completely absent interradicular bone of 46 tooth in a 35-year-old woman with generalized periodontitis is presented. After endodontic treatment and recovery of the tooth crown we undertook surgical treatment of the bone defect: open curettage, using the technique of Ramfjord and bony reconstruction with aloplastic material bioplant HTR (septodont). The preoperative preparation included clinical prophylaxis and chemical plaque inhibition; postoperatively, rinsing the mouth twice a day with 0.5% metronidazole. The patient was followed up clinically and radiographically up to the 6th month after treatment when the bone structure regenerated.

Humans↗
PubMedDate not supplied

Cartilage cell differentiation: review.

Differentiation of cartilage cells from embryonic precursor cells is characterized by the onset of biosynthesis of at least two cartilage-specific gene products, type II collagen and cartilage-specific chondroitin sulfate proteoglycan (CSPG). Biochemical and immunological assays for these compounds now allow rapid, quantitative, and specific determination of the onset of cartilage differentiation, and present several advantages over assays that use histochemical stains or [35S]-sulfate incorporation into glycosaminoglycans. Chondrogenic differentiation also is associated with the formation of extracellular, high MW proteoglycan (CSPG) aggregates containing hyaluronic acid and the loss of fibronectin, or LETS protein, a cell surface glycoprotein found on presumptive chondroblasts, fibroblasts, and several other cell types. Comparatively little insight has been gained recently regarding the mechanism of cartilage cell differentiation. A number of factors or "inducers" of cartilage differentiation, such as chondroitin sulfate proteoglycan, notochord, spinal cord, low oxygen tension, and collagen substrates, increase the amount of glycosaminoglycan synthesis per cell, but the question remains open as to whether these factors also selectively increase the number of cells differentiating from precursor cells into chondroblasts, or whether they only increase cell viability. Other factors, such as conditioned medium from chondrocyte cultures, increase significantly the number of chondrocyte colonies arising in mass cultures of limb bud mesenchyme, but differentiation of nonchondrogenic cells is stimulated as well. Similarly, many inhibitors of cartilage differentiation, such as BrdUrd and 6-amino nicotinamide, also inhibit myogenic differentiation. It is possible that a unique and specific inducer or regulating factor of cartilage cell differentiation may not exist, for cartilage differentiation of normal embryonic mesenchyme can be triggered by a variety of environmental conditions, such as cell density, pH, potassium ion concentration, and fetal calf serum. These results imply that the temporal and spatial controls of cartilage differentiation are governed by environmental influences that are each of rather low specificity, but which together synergistically generate a morphogenetic control of high specificity. Signals which appear able to mimic those controlling normal cartilage differentiation seem to be exchanged during formation of ectopic cartilage. Muscle tissue and periosteum can be triggered to form cartilage by demineralized bone matrix. Chick limb bud epithelium induces type II collagen synthesis in embryonic mouse tooth germ, whereas homologous, oral epithelium induces the formation of dentin (type I collagen). Thus, the type of response elicited from mesenchyme cells can be determined by nearby epithelia, and that response frequently can be the formation of cartilage.

Animals↗