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 469 records · Page 26Linked to original sources

PubMed1996

In vitro measurement of enamel demineralization in the assessment of fluoride-leaching orthodontic bonding agents.

The aim of this study was to measure in vitro demineralization around orthodontic brackets, bonded with five different bonding agents. Two conventional bonding agents, two fluoride-leaching agents, and a glass ionomer were tested. A sixth group utilized a fluoride varnish after bonding. The amount of dissolved enamel mineral was determined from increases in the phosphorus concentration in the demineralizing solution and measurements were made over a 4 week period. The results confirmed that when fluoride is present in the form of a fluoride-leaching bonding agent or a fluoride varnish, resistance to demineralization is enhanced. Analysis of variance showed that Ketac-cem, Concise with Duraphat, and Pulpdent O.B.A. performed statistically significantly better than Concise, Bond-fast, and Rely-a-bond, in resisting enamel demineralization.

Adolescent↗

PubMed2006

Caries-preventive potential of an adhesive patch after thermomechanical loading--a microbial-based in vitro study.

PURPOSE: To assess the enamel-protective potential of a newly devised adhesive patch for smooth enamel sealing. MATERIALS AND METHODS: Approximal surfaces of 30 extracted molars were divided into three areas: the buccal thirds were treated with a flowable composite (Tetric Flow, Ivoclar Vivadent) and served as negative control sites, the lingual thirds were left untreated and served as positive control sites, and the middle thirds served as the test areas. This was sealed with either 1. a twofold application of an unfilled resin (Heliobond, Ivoclar Vivadent), 2. an adhesive prototype patch (Ivoclar Vivadent), or 3. an adhesive patch in combination with a flowable composite. After thermomechanical loading and demineralization in a microbial-based artificial caries chamber, demineralization depth was assessed using a confocal laser scanning microscope. RESULTS: Negative control sites treated with the flowable composite showed no signs of demineralization. Areas treated with the patch showed no signs of demineralization, irrespective of whether it was used in combination with a flowable composite or directly bonded to the enamel. Caries-like lesions in untreated sites showed a mean depth of 134.3 +/- 35.9 microm. Demineralization depth at sites treated with the unfilled resin was 76.2 +/- 26.5 microm (p = 0.023). CONCLUSIONS: Under the conditions of the present study, the adhesive patch under investigation completely protected the underlying enamel from demineralization. This merits further study to assess its potential as an interproximal sealant.

Adhesives↗

PubMed1997

Fluoridated etching on orthodontic bonding.

Enamel demineralization that occurs adjacent to directly bonded orthodontic attachments is of great concern to orthodontists. One procedure suggested to overcome this problem is to use fluoride treatment in an acid etch. The purpose of this study was to evaluate the bond strength and the debonding interface distribution of adhesive, with and without the use of fluoridated etch on enamel, before bonding. Ten teeth were etched with 37% phosphoric acid (H3PO4), incorporated with 1.23% sodium fluoride (NaF) for 15 seconds. The control group of 10 teeth was etched with the 37% H3PO4 solution for 15 seconds without fluoride. Fluoride on enamel was first detected with scanning auger microscribe/photoelectron spectroscopy in the fluoridated etching group. The brackets were then bonded on the labial surfaces of the crowns of both groups of teeth. The bracketed teeth were tested, with an Instron machine, to determine the tensile bond strength, as well as with a scanning electron microscope, and by mapping with an energy dispersive x-ray spectrometer to detect the debonding interfaces. The results showed that the fluoride was found on the enamel after fluoridated etching for 15 seconds. The bond strength and debonding interface distribution between the two groups were not statistically significantly different. Enamel detachment was not present in either group. Hence, the fluoridated etching with 1.23% NaF may have a clinical application in the prevention of demineralization or caries surrounding and under orthodontic brackets bonded to enamel.

Acid Etching, Dental↗

PubMed1997

In vitro enamel demineralization and the marginal gap of simulated cast restorations with three different cements.

PURPOSE: This study investigated 1) the relationship between marginal gap sizes and enamel demineralization, and 2) the influence of three cements on this enamel demineralization. MATERIALS AND METHODS: Horizontal sections of 60 noncarious, freshly extracted human third molars were randomly assigned to one of four groups. Simulated cast restorations were attached to the specimens with 1) zinc phosphate cement, 2) glass ionomer cement, 3) composite resin cement, or 4) no cement (control). The tooth/restoration gaps were controlled at 51, 102, and 204 microns. The specimens were incubated for 16 weeks in buffered lactic acid gelatin to induce demineralization. Photomicrographs were obtained from sections of each sample using a polarized light microscope. Three evaluators measured wall and primary enamel lesion depths allowing for the determination of a demineralization ratio (DR). Data were analyzed by repeated-measures ANOVA (alpha = 0.05). RESULTS: The between-evaluator effects were not significant. All evaluators agreed that DR was significantly related to cement (p = .0001) but not to marginal gap size. The resin cement had the smallest DR (0.7 +/- 0.3), and the control group had the greatest (4.4 +/- 2.0). CONCLUSIONS: The presence of any one of the three investigated cements resulted in decreased demineralization. The amount of demineralization was unaffected by marginal gap size.

Analysis of Variance↗

PubMed2002

Effect of application time of APF and NaF gels on microhardness and fluoride uptake of in vitro enamel caries.

PURPOSE: To evaluate the effect of time of fluoride application gel, acidulated or neutral, on in vitro enamel resistance to demineralization and fluoride uptake. MATERIALS AND METHODS: One hundred and ninety-two human enamel blocks were used in this study and 144 were treated with fluoride gel, acidulated or neutral, for 1 or 4 minutes. Ninety-six blocks treated with fluoride and 24 control blocks were submitted to a high cariogenic challenge. After the pH-cycling, enamel demineralization was assessed by surface and cross-sectional microhardness. Fluoride in the enamel blocks was also determined after removing an enamel layer by etching acid. RESULTS: Acidulated fluoride gel formed more fluoride in enamel than neutral gel (P<0.05), and it was also more efficient in reducing the demineralization of the enamel blocks submitted to a cariogenic challenge than the neutral one (P<0.05). It was found that the time of application was significant in terms of fluoride uptake, but it did not render the enamel more resistant to demineralization.

Acidulated Phosphate Fluoride↗

PubMed2004

Morphological evaluation of enamel surface after application of two 'home' whitening products.

PURPOSE: The purpose of this study was to investigate the effect on enamel surface morphology of two commercially available bleaching products (AZ Whitestrips 6% hydrogen peroxide - Procter & Gamble; Platinum TWS 10% carbamide - Colgate Oral Pharmaceuticals) and their ability to prevent enamel demineralization in the presence of cariogenic solution, with or without saliva. MATERIALS AND METHODS: Forty sound teeth were used to obtain 90 enamel fragments. Lactic acid (pH = 4.4) was used as a demineralizing cariogenic solution. The specimens were randomized into eight groups: Group A: product A + cariogenic solution; Group B: product B + cariogenic solution; Group C: cariogenic solution; Group D: (control group) stored in deionized water; Group E: product A + deionized water; Group F: product B + deionized water; Group G: product A + saliva; Group H: product B + saliva. Scanning electron microscope (SEM) analysis was performed to detect the type of lesions induced by the treatments. A score rating system was used to perform a non-parametric statistical analysis. RESULTS: Our study confirms that enamel alterations (i.e. removal of intraprismatic core and presence of deep porosities and pits) occur as a result of the application of a cariogenic solution (lactic acid). The enamel surface presented a honeycomb surface only in untreated samples previously stored in lactic acid solution. Conversely, both products were able to prevent enamel alterations caused by exposure to lactic acid. Saliva treatment reduced the degree of enamel lesions of both treated and untreated groups. Treatment with product A achieved better preservation of enamel integrity. CONCLUSION: Whitening treatment conducted with two 'home' bleaching agents had no adverse effects on enamel surface morphology. Several morphological aspects suggest that the tested products may even prevent demineralization of the enamel surface after exposure to lactic acid.

Carbamide Peroxide↗

PubMed2000

Effects of self-applied topical fluoride preparations in orthodontic patients.

The purpose of this study was to compare the effectiveness of toothbrushing followed by fluoride rinsing, fluoride gel brushing, or fluoride gel dentifrice brushing alone in controlling the demineralization that often follows orthodontic treatment. Seventy-eight consecutive adolescent patients undergoing orthodontic care were divided into 3 groups: group 1 (control) used a low-potency, high-frequency fluoride rinse; group 2 used a high-potency, high-frequency fluoride brush-on gel; and group 3 used a high-potency, high-frequency fluoride gel dentifrice. When pretreatment levels of demineralization were subtracted from posttreatment values, both gel groups displayed a significant difference (P < .05) in smooth surface demineralization sites when compared to controls. Reversal of white-spot lesions occurred in 15% of sites that exhibited pathology as a result of the fluoride and preventive regimen. These results indicate that a daily use of a 5000-ppm fluoride gel along with toothbrushing with a fluoride paste or brushing twice daily with a 5000-ppm fluoride dentifrice alone provides greater protection beyond that of tooth-brushing with a fluoride paste (1000 ppm) and rinsing with a 0.05% sodium fluoride rinse.

Adolescent↗

PubMed2004

In vitro microleakage of adhesive-sealed dentin with lactic acid and saliva exposure: a radio-isotope analysis.

OBJECTIVES: The aim of this study was to evaluate the dentin-protective potential of two dentin-bonding systems (Syntac and Clearfil SE Bond) on artificial saliva and lactic acid exposure. METHODS: Radiochemical analysis in combination with polarization-microscopy was used in the current study. Different applications in MOD preparations in irradiated human molars were compared. Untreated cavities and cavities covered with flowable resin served as controls. Forty-eight specimens were immersed in artificial saliva (pH 7.5), 48 in lactic acid (pH 4). Activity of (32)P was measured between days 1 and 21 and loss of mineralized tissue was estimated. RESULTS: In lactic acid, cavities sealed with single bond, double bond or bond plus cavity sealer application resulted in significantly lower mineralized tissue loss compared to negative controls (p < 0.05). Upon both saliva and lactic acid exposure, bonding plus sealer application proved to be the most protective treatment (p < 0.05). CONCLUSIONS: Based on these in vitro findings it may be advisable to use a filled cavity sealer or a flowable resin to protect dentin from demineralization. The radiochemical analysis appeared to be valuable in evaluating the protective potential of bonding agents against dentin demineralization.

Acid Etching, Dental↗

PubMed2007

In situ tracing the process of human enamel demineralization by electrochemical impedance spectroscopy (EIS).

OBJECTIVE: The purpose of this study was to in situ characterize the demineralization (namely dissolution of hydroxyapatite) on the surface of the human enamel using electrochemical impedance spectroscopy (EIS) technology. METHODS: Fresh human third molars extracted without visible evidence of caries, were used in this study. After they were immersed in a demineralizing solution prepared from lactic acid and carboxy methyl cellulose sodium (Na-CMC) buffering at pH 4, demineralization happened on their surfaces. EIS of the specimens were measured at a series of immersed interval. X-ray diffractometer (XRD) were used to distinguish the microstructure of the surface layer of the specimens. The depositions that appeared in the demineralizing solution after 46 h immersion were analyzed by fourier transform infrared spectrometer (FTIR). RESULTS: XRD analysis revealed that the percentage of intensity (I%) of HAP gradually decreased with the elapsed immersing time, which indicated the dissolution of HAP columns of enamel. Nyquist spectra were fitted with an equivalent circuit characterized by some parameters, such as Q and R(p) (error<0.1%). Changes of the parameters' values revealed that the rate of demineralization accelerated at the forepart of the demineralization, but slowed down beyond 70 h immersion. CONCLUSIONS: The results suggested that EIS was proved to be a useful method for in situ investigating and in vivo detecting the demineralization of the enamel.

Analysis of Variance↗

PubMed2006

In situ mineral loss inhibition by CO2 laser and fluoride.

Laser and fluoride treatments have been shown to inhibit enamel demineralization in the laboratory. However, the intra-oral effects of this association have not been tested. This study assessed in situ the effect of a Transversely Excited Atmospheric CO2 laser (lambda = 9.6 mum) and the use of pressure fluoridated dentifrice on enamel demineralization. During two 14-day phases, 17 volunteers wore palatal appliances containing human enamel slabs assigned to treatment groups, as follows: (1) non-fluoride dentifrice, (2) CO2 laser irradiation plus non-fluoride dentifrice, (3) fluoride dentifrice, and (4) CO2 laser irradiation plus fluoride dentifrice. A 20% sucrose solution was dripped onto the slabs 8 times per day. The specimens treated with laser and/or fluoridated dentifrice presented a significantly lower mineral loss when compared with those from the non-fluoride dentifrice group. The results suggested that CO2 laser treatment of enamel inhibits demineralization in the human mouth, being more effective when associated with fluoride.

Adult↗

PubMed2005

Measurement of white lesions surrounding orthodontic brackets: captured slides vs digital camera images.

Digital images provide an efficient means of processing and storing clinical images and are increasingly being used in orthodontic practice. However, for research purposes it must be shown that measurements from digital images are as reliable as those from captured slides, particularly in the area of postorthodontic demineralization. The aim of this in vitro study was to compare the assessment of demineralized white lesions surrounding orthodontic brackets using images produced from captured slides with those from a digital camera. Thirty teeth with orthodontic brackets and a systematic arrangement of artificially induced demineralization were used. Standardized images of the teeth were taken in 35-mm slide format and using a digital camera. The slides were scanned and saved as digital images. All the images were numbered, recoded in a random order, and assessed by a second investigator. The image was examined for the presence or absence of demineralization. This was compared with the actual demineralization pattern, and the positive and negative predictive values were calculated. Twenty images from each group were randomly chosen and duplicated for an assessment of measurement error. The positive and negative predictive values were better from the digital images (0.92 and 0.81) than from the captured slides (0.88 and 0.74). The percentage agreements for the repeat assessments of the same slide were similar (96% for the captured slides and 93% for the digital images). Measurements of enamel demineralization using images from a digital camera are as accurate and reproducible as images captured from a photographic slide.

Dental Enamel↗

PubMed2006

Acid susceptibility of arrested enamel lesions: in situ study.

Arrested lesions are more resistant to a new cariogenic challenge, but the degree of surface rehardening needed to achieve this is unknown. The aim of this in situ study was to analyze the acid susceptibilityof newly formed and arrested enamel lesions with known arrestment period and surface microhardness. Six individuals wore an oral appliance with human enamel blocks for 3 periods: (1) 21 days of demineralization due to plaque accumulation and cariogenic challenge, 4 blocks/person (nonfluoride dentifrice); (2) 75 days of arrestment, brushing with fluoride dentifrice, 2 blocks/person; (3) 21 days of demineralization, 5 blocks/person: 1 sound block, 2 demineralized blocks and 2 demineralized and arrested blocks (nonfluoride dentifrice). After period 1, all blocks showed a dull whitish surface characteristic of active, noncavitated lesions. After arrestment, the surfaces assumed a shiny and smooth aspect. The Knoop hardness number (KHN, mean+/-SD) of the sound blocks was 307.6+/-15.0. After period 1, microhardness decreased significantly to 162.6+/-33.5 KHN (p<0.001). The microhardness of subsequently arrested lesions (279.8+/-23.1 KHN) was significantly greater than after demineralization, but lower than that of sound enamel. Arrested enamel did not show a decrease in microhardness when subjected to a new cariogenic challenge and after the same cariogenic challenge showed similar microhardness to sound enamel. The results showed that, although noncavitated lesions probably take years to reach microhardness levels like sound enamel, this does not imply that special care, in addition to the ones normally given to sound tooth surfaces, is necessary.

Acids↗

PubMed2003

The effect of argon laser irradiation on demineralization resistance of human enamel adjacent to orthodontic brackets: an in vitro study.

Argon lasers, because of their significant timesavings over conventional curing lights, have been investigated for use in bonding orthodontic brackets. They are also being investigated for their ability to confer demineralization resistance on enamel, which is of great interest in orthodontics. A two-part in vitro study on 86 human posterior teeth was conducted to determine the effects of a five-second argon laser exposure on shear bond strength and to evaluate the effects of a five- and 10-second argon laser exposure (250 mW) on demineralization of enamel surrounding orthodontic brackets after exposure to an artificial caries bath. Brackets cured with the argon laser for five seconds yielded mean bond strengths similar to those attained with a 40-second conventional light-cured control (n = 13 per group, 20.4 vs 17.8 MPa). Brackets cured with the argon laser for 10 seconds resulted in significantly lower mean lesion depth when compared with a visible light control (n = 20 per group, 107.8 vs 137.2 microm, P = .038). There were no statistically significant differences in lesion depth between the five-second argon laser and the visible light control groups. Overall, there was a 15% and 22% reduction in lesion depths for the five- and 10-second group, respectively. Poor correlations were found between the clinical appearance of decalcifications and their lesion depth. Argon lasers used for bonding orthodontic brackets would save a significant amount of chair time while possibly conferring demineralization resistance upon the enamel.

Acetates↗

PubMed2005

Inhibition of root caries progression by an antibacterial adhesive.

A dentin primer containing the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) has been shown to penetrate and kill the bacteria in artificially demineralized dentin. We hypothesized that an experimental adhesive system, which incorporates the MDPB-containing primer, would be effective in inhibiting the progression of root caries in vitro. Artificial caries lesions were prepared by either an acid-gel or a Streptococcus mutans culture technique on the roots of extracted human teeth. The progression of these lesions after the application of the experimental or proprietary adhesive system was examined. Further demineralization was completely prevented by the experimental adhesive system, while lesions managed with the proprietary materials showed limited ability to inhibit further demineralization. We conclude that the experimental adhesive system can inhibit the progression of root-surface caries in vitro, through a combination of its antimicrobial activity and sealing of the demineralized dentin.

Acetone↗

PubMedDate not supplied

Influence of fluoride in saliva during the early cariogenic changes in the enamel of boys and girls.

In boys and girls cariogenic changes in the dental enamel in relation to fluoride (F-) concentrations in stimulated and unstimulated saliva were studied in a six-month period. Also the use of various types of applications of F- was assessed. No difference in the use of F- between boys and girls before and after the interval was observed. Also no clear differences were found between boys and girls in the levels of F- in both types of saliva, determined at the end of the six-month period. The most important finding was that for all children, a significantly positive relationship was found between the disappearance of white spots turning into sound enamel (regression) and the F-concentration in unstimulated saliva. In addition, girls who developed new white spots had higher levels of F-, but those who developed new cavities had lower F- levels in both types of saliva. Apparently F- can prevent dental caries by acting very early on remineralization and demineralization processes in enamel surfaces.

Adolescent↗

PubMedDate not supplied

Demineralization inhibition at glass-ionomer cement and amalgam restoration margins in conjunction with additional fluoride regimens.

The purpose of this study was to evaluate demineralization inhibition at restoration gingival margins. The study compared the effectiveness of a fluoride-releasing restorative material and topical fluoride regimens utilized individually and in conjunction with fluoridated materials. Glass-ionomer restorations demonstrated significantly less dentin demineralization than amalgam restorations at restoration margins when the restorations were exposed to no external fluoride, when the restorations were brushed with a fluoridated dentifrice twice per day, and when the restorations were exposed to a fluoride rinse (p, 0.05). There was no significant difference in dentin demineralization adjacent to glass-ionomer and amalgam restorations when both a fluoride rinse and a fluoridated dentifrice were used on a daily basis over 30 days, in vitro.

Cariostatic Agents↗

PubMed1998

Laser fluorescence detection of demineralization in artificial occlusal fissures.

Laser fluorescence (LF) has been used previously to detect early smooth-surface lesions. Although its use for detection of occlusal demineralization has been implicated, it has not been demonstrated. The aim of this study was to determine whether LF could detect demineralization in the base of artificial fissures. To employ LF for detection of occlusal demineralization an apparatus was devised to direct laser light into fissures and simultaneously detect fluorescence from the base of the fissures. Three groups (n = 40/group) of differing fissure types were prepared (straight wall, converging and diverging wall) with either a sound or lesioned base. One half of each group was examined with LF and dye-enhanced LF (DELF); the other half was examined with LF, exposed to plaque, examined with LF and DELF, air-polished and examined with DELF. All images were scored twice as either (1) carious; (2) sound, or (3) undetermined, by a group of 3 examiners. For fissures without plaque, the average sensitivity was higher for DELF (0.76) than for LF (0.54) (p < 0.05). Likewise, the average specificity was higher for DELF (0.64) than for LF (0.29) (p < 0.05). In the presence of plaque, sensitivity was higher for DELF (0.91) compared to LF (0.43); however, specificity was lower for DELF (0.05) compared to LF (0.55). When the fissures were air-polished and then examined with DELF, sensitivity averaged 0.82 (p < 0.05), and specificity increased consistently (average 0.51, p < 0.05). It was concluded that, in the absence of plaque, DELF was a better diagnostic tool than LF for detection of demineralization in artificial fissures.

Animals↗

PubMed1992

Subsurface demineralization in dental enamel and other permeable solids during acid dissolution.

Subsurface demineralization of dental enamel during acid dissolution has been reported many times, but its cause remains obscure. At first, the phenomenon was thought to result from the physical structure of enamel. More recent studies have shown that subsurface demineralization occurs in other permeable solids, indicating that there must be more fundamental factors involved in this curious effect. In order for this phenomenon to be investigated, dissolution experiments were carried out by means of real-time scanning microradiography in various systems, including enamel, or aggregates of hydroxyapatite (calcium, strontium, or barium), or hydroxides (calcium or magnesium). These were chosen to discriminate between effects of structure and composition. It was found that it was not possible for the demineralization observed in these systems to be attributed to a common feature. From this, it is concluded that subsurface demineralization in enamel and other mineralized tissues should not be ascribed to a single cause.

Acetates↗