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 19 recordsLinked to original sources
PubMed1994

A comparative histologic study of the pulp-dentinal interface in undemineralized and demineralized tooth sections.

This study examines cellular differences between undemineralized and demineralized tooth sections. The material comprised unerupted and partly erupted third molars. After fixation for 24 h, 10- to 15-microns ground sections were prepared from half of the tooth, using a cutting-grinding system. The sections were compared with demineralized routine sections from the other half of the tooth. Undemineralized sections showed a better capacity for preserving the tissue integration. Especially between the odontoblast layer and the predentin a low frequency of disjunctions or tears were noted. At this level of examination fixation quality and vacuole frequency (intra-cellular spaces) did not show any differences between the two methods.

Cell Membrane↗
PubMed2001

Relationships between medication intake, complaints of dry mouth, salivary flow rate and composition, and the rate of tooth demineralization in situ.

The aim of this study was to describe the relationships between the rate of tooth demineralisation and medication intake, subjective feeling of dry mouth, saliva flow, saliva composition and the salivary level of lactobacilli. The study group consisted of 28 subjects that were divided into three groups according to their unstimulated whole saliva flow rate. Group 1 had an unstimulated saliva low rate < or =0.16 ml/min (n=10), group 2 had one from 0.17--0.30 ml/min (n=9), and group 3 had one >0.30 ml/min (n=9). The rate of tooth demineralization was determined as mineral loss assessed by quantitative microradiography of human root surfaces, exposed to the oral environment for 62 days in situ. The unstimulated and stimulated saliva flow rates, pH, bicarbonate, calcium, phosphate, and protein concentrations, as well as the degree of saturation of saliva with hydroxyapatite and the saliva buffer capacity were determined. The results showed that almost all subjects developed demineralization, albeit at highly varying rates. Eighty-five percent of the subjects in group 1, 33% of the subjects in group 2, and 0% of the subjects in group 3 developed mineral loss above the mean mineral loss for all the root surfaces in this experiment. Futhermore, group 1 differed significantly from groups 2 and 3 in having a higher medication intake, a more pronounced feeling of dry mouth, lower stimulated saliva flow rate, lower stimulated bicarbonate concentration, lower unstimulated and stimulated compositional outputs (bicarbonate, calcium, phosphate, and protein), and a higher Lactobacillus level. The best explanatory variable for high mineral loss in this study was a low unstimulated saliva flow rate. In conclusion, our results suggest that an unstimulated salivary flow rate < or =0.16 ml/min as described by Navazesh et al. (1992), is a better indicator of increased caries risk due to impaired salivation, than the currently accepted definition of hyposalivation (unstimulated saliva flow rate < or =0.10 ml/min), which relates to the function of the salivary glands (Sreebny, 1992).

Adult↗
PubMed2004

Early differentiation between caries and tooth demineralization using laser-induced autofluorescence spectroscopy.

BACKGROUND AND OBJECTIVES: The intrinsic fluorescence of carious human teeth, of different stages of teeth demineralization, and the correspondence of such fluorescence to the mineral and organic distribution within the lesions were investigated. STUDY DESIGN/MATERIALS AND METHODS: Fluorescence spectra of teeth excited with 337 nm nitrogen laser were recorded. Spectra were obtained from healthy enamel, dentine, demineralized areas, and different carious stages of the teeth investigated. RESULTS: Spectra obtained from sound enamel consisted of one intensive peak at 480-500 nm and one secondary peak at 430-450 nm. In dentine, this secondary component had much higher intensity. Fluorescence spectra of normal teeth were similar to those of enamel layer. A significant decrease of the intensity of the fluorescence signal was observed in both cases-in demineralized teeth and in carious lesion. The appearance of a fluorescence peak in the red spectral region was observed in the spectra of the initial carious lesions. In the teeth demineralization process, we observed an increase of the relative fluorescence peak intensity at 430-450 nm related to thinned out of enamel. CONCLUSIONS: A differentiation between initial tooth demineralization and early stages of caries could be made by the laser-induced fluorescence spectroscopy method.

Dental Caries↗
PubMed1990

[Induced hematopoietic foci in mice. I. Induction of extraskeletal hematopoietic areas using demineralized tooth matrix].

Conditions of formation of induced osteo-hemopoietic foci in mice, in response to ectopic implantation to them of homologous demineralized tooth matrix, have been studied. It is shown that the hemopoietic tissue of the induced foci is similar to the bone marrow of the skeletal bones by the morphological parameters and cellular composition; differentiation of precursor cells takes place in all three directions of myelopoiesis. Induced foci formation under the capsule of the kidney occurs much later (after 5-8 months) than under the skin of muscular fascia (1-1.5 months). The induced hemopoietic foci functioning continues at least for one year.

Animals↗
PubMed1998

[Velocity of erosion and factors that modify human tooth demineralization in vitro].

Velocity of erosion on human teeth exposed to a carbonated beverage as a function of time and temperature has been studied in vitro, as well as the effect of the experimental formation of a acquired pellicle and the influence of the inclusion of either F or saliva on the dissolving capacity of beverage. During the first stage of exposition, erosion as a function of time showed a biphasic curve, being the rate low during the first 10 minutes time; thereafter, velocity increased and remained stable until the 60 minute incubation period finished. At the second stage, demineralization followed a monophasic curve, displaying a stable rate until the end of it. At the initial stage, molar ratio Ca/P was much less than that corresponding to hydroxyapatite (approximately 1.67); however, as exposition to erosive beverage was prolonged, the former ratio reached values compatible with this mineral species. F or saliva incorporation together with the experimental formation of the acquired pellicle significatively reduced beverage demineralizing capacity (p < 0.0001). This finding introduces the possibility of attenuating such erosive capacity of carbonated beverages by including not excessively toxic fluoride quantities.

Adult↗
PubMed1970

Transformation of fibroblasts by allogeneic and xenogeneic transplants of demineralized tooth and bone.

Xenogeneic transplants of powdered, dehydrated, demineralized matrix of bone and tooth were well tolerated in three species of rodents. Differences between the species were found in competence of fibroblasts to be transformed into cartilage and bone in vivo by these preparations. Rat fibroblasts were most susceptible to transformation of this sort; they were transformed by demineralized dentin of guinea pig, mouse, and rat, and to a limited extent, by a specimen of decalcified human bone.

Alkaline Phosphatase↗
PubMed1993

Scanning microradiographic study of the kinetics of subsurface demineralization in tooth sections under constant-composition and small constant-volume conditions.

The kinetics of subsurface demineralization of tooth sections has been studied in real-time by scanning microradiography (SMR). Demineralization was carried out: (1) with a large volume of solution buffered to pH = 4 to maintain a constant composition; and (2) in a small constant volume (approximately 3 mL), buffered initially at pH = 4, so that the degree of saturation at the tooth surface increased as the tooth dissolved. At constant composition, the change in lesion depth, Y, with time, T, followed a linear relation, Y = a + bT, for T > 44 +/- 5 h. Before this time, the relation could be approximated by a linear one with different a and b constants. At constant volume, Y = q(1-e-r(T + s)) for all T, where q, r and s are constants. Similar relations, with different constants, were found for the mineral loss per unit area of lesion exposed to acid. These results showed that the process of demineralization under the rather severe conditions used was essentially a surface-controlled process. The change of slope at approximately 44 h and the presence of the constant s in the exponential function were attributed to a change in kinetics after formation of the surface layer.

Dental Enamel↗
PubMed2001

The hormonal milieu in early stages of bone cell differentiation modifies the subsequent sex-specific responsiveness of the developing bone to gonadal steroids.

We have established previously that rat bone tissue, as well as rat and human-derived bone cells in culture, show a sex-specific response to gonadal steroids in stimulation of the specific activity of the BB isozyme of creatine kinase (CK) and DNA synthesis. This response could be modified by manipulation of the endocrine environment during early stages in rat development. To further examine the influence of changing hormonal steroid milieu and vitamin D status on the action of gonadal steroids in developing bone tissue, we used two models of ectopic bone formation: demineralized tooth matrix (DTM) implanted under the skin, and femoral bone marrow (BM) transplanted under the kidney capsule of a syngeneic recipient mouse. The response to gonadal steroids in ossicles developed from implanted DTM depended on the recipient's gender; injection of estradiol 17beta (E2; 5 microg) into young female mice 21 days after DTM implantation increased, 24 h later, CK activity in the newly formed ossicles by approximately 60%, whereas injection of dihydrotestosterone (DHT; 50 microg) had no effect on CK activity. In contrast, in male mice, DHT but not E2 increased CK activity in the ossicles by approximately 50%. This sex-specific response was abolished in gonadectomized mice resulting in a similar response of the ossicles to both E2 and DHT. When DTM was implanted into vitamin D- deficient female mice, there was a lower basal CK activity and a significantly diminished response to E2 in the newly formed bone tissues. When BM, which contains mesenchymal and stromal cells and committed osteoprogenitor cells, was transplanted into 6-week-old intact or gonadectomized female or male mice, the response of the newly formed bone ossicles, 21 days after transplantation, to E2 or to DHT was according to the gender of the donor. Bone formed from BM obtained from female mice responded to E2 only and those formed from male BM responded to DHT only. Ossicles developed from BM obtained from gonadectomized mice showed lack of response to either gonadal steroid. Furthermore, only approximately 25% of the BM transplants obtained from castrated (CAST) male donors developed into ossicles. Ossicles formed from BM obtained from vitamin D-deficient female donors showed lack of response to gonadal steroids. These findings suggest that the manipulation of the hormonal milieu in early stages of the differentiation sequence of bone cells modifies the subsequent selective responsiveness of the developing bone tissue to gonadal steroids.

24,25-Dihydroxyvitamin D 3↗
PubMedDate not supplied

Identify, protect, restore: emerging issues in approaching children's oral health.

Treating dental caries as an infectious disease requires the clinician to identify risk factors and tooth demineralization as early as possible. This early recognition of risk allows the dentist to implement prevention regimens before significant oral disease becomes apparent. Prevention includes rebalancing the oral environment to its natural state to prevent oral disease progression. Bacterial control, buffering acidic pH, and providing calcium, phosphate, and fluoride all can aid in rebalancing the oral cavity. Rebalancing can protect potential demineralization of tooth structure; it also can repair early lesions. Once cavitation occurs, conservative restoration with biomimetic materials is indicated. This approach dictates identifying and assessing potential caries risk factors early, preventing caries by addressing these primary risk factors, eliminating or minimizing their effects, and restoring teeth with minimally invasive techniques.

Child↗
PubMed1989

Prevention of sucrose-induced demineralization of tooth enamel by chewing sorbitol gum.

Measurements were made of the effect of chewing sorbitol gum on the intra-oral demineralization induced by rinsing with 10% sucrose solutions. Blocks of bovine enamel were covered with a layer of Streptococcus mutans IB1600, and mounted on palatal appliances that were worn by five subjects for defined periods of time. Enamel demineralization was determined by following changes in iodide penetrability (delta Ip) of the enamel surfaces. Delta Ip increased to a maximum of about 15 units between 30 and 45 min, while the pH of the S. mutans plaque dropped to below 4 by 15 min. Plaque pH returned to 4.9 by 60 min. Chewing sorbitol gum after the sucrose rinse minimized further increases in delta Ip and brought about a more rapid return of the S. mutans plaque pH toward neutrality. The effect of chewing gum was greater when chewing was initiated earlier so that, when gum was given at five min after the sucrose rinse, demineralization was only 37% of that obtained without gum. The findings confirm earlier reports on the effect of gum on plaque pH, and directly demonstrate the profound protective effects that chewing sorbitol gum can have on tooth enamel.

Adult↗
PubMed1981

Fluoride remineralization of demineralized bovine tooth enamel and hydroxyapatite pellets.

Both bovine enamel and hydroxyapatite pellets were remineralized in a fluoride-containing remineralization solution after prior demineralization for various lengths of time. In both the enamel and pellet systems, the degree of remineralization attainable was directly related to the extent of prior demineralization, although the demineralized material was never 100% recovered in remineralization. In some cases, fluoride levels up to several thousand parts per million were found at depths as great as 50 micrometers from the surface. The stoichiometry of the remineralized material and electron microprobe examination were consistent with the formation of fluoridated hydroxyapatite rather than calcium fluoride.

Animals↗
PubMed1988

Dissociative extraction and partial purification of osteogenin, a bone inductive protein, from rat tooth matrix by heparin affinity chromatography.

Implantation of demineralized tooth matrix in subcutaneous sites results in new bone formation locally. The osteoinductive activity of the tooth matrix was dissociatively extracted in 4.0 M guanidine hydrochloride and the residue was devoid of biologic activity. The bone inductive protein, osteogenin, was partially purified by heparin affinity chromatography. The heparin binding fraction initiated the bone differentiation cascade when implanted with guanidine extracted, inactive bone or tooth matrices. These results imply a cooperative interaction between the soluble osteogenin and collagenous substratum in bone induction.

Animals↗