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PubMed2005

Comparison of three topical fluorides using computer imaging.

The purpose of this in vitro study was to evaluate the short and long-term effectiveness of fluoride varnish and compare it with the two most commonly used topical fluorides, i.e., fluoride gel and foam. A second purpose of the study was to compare the effectiveness of these preparations on primary and permanent teeth. Enamel slabs with a thickness of 500 microns were obtained from caries free primary molars and premolars. They were divided into four groups: control, foam (F), gel (G) and varnish (V). Fluorides were applied to the enamel slabs according to the manufacturer's instructions and were placed in a 5.1 pH acidic gel for one week. The amount of demineralization from the enamel was measured by calculating the amount of light reflected from these surfaces. This was done by using a Charged Couple Device attached to a high resolution microscope with image processing software, Optima 5.22. The enamel slabs were placed in a freshly prepared acidic gel for a second week without application of fluorides. This was done to mimic a situation where fluoride is eventually brushed away from teeth. Reflective images were recorded under the previously described conditions. A two-way analysis of covariance was used to compare the treatments. The results showed no statistically significant difference (with Bonferroni correction) in the effectiveness of different fluoride preparations over the short-term (Week I comparison; p-values: F vs. G 0.079, F vs. V 0.030, G vs. V 0.44). However, the long-term protection provided by fluoride varnish was far more than fluoride gel and foam (Week II comparison; p-values: F vs. G 9X10-5, F vs. V 7X10-8, G vs. V 1X10-4). Fluorides were equally effective for both primary and permanent enamels (p-value 0.24). The results of this study suggest that fluoride varnish is beneficial for use with white spot lesions, newly erupted permanent teeth and early decalcification in primary dentition.

Acidulated Phosphate Fluoride↗
PubMed2000

Remineralization effects of a two-solution fluoride mouthrinse: an in situ study.

Results from previous studies show that a two-solution fluoride (F) rinse is significantly more effective than a NaF rinse of the same F content of 250 microg/g (ppm) in remineralizing enamel and root lesions in an in vitro cyclic de- and remineralization model. In the present study, the two-solution rinse and two NaF rinses with F contents of 250 ppm and 1000 ppm were evaluated in an intra-oral remineralization model. Caries-like lesions were formed in the enamel of extracted human molars with the use of a pH 4 demineralizing solution. Thin sections of the enamel (approximately 120 microm) containing lesions were prepared, and the mineral contents of the lesions were assessed by quantitative microradiography. With the cut surfaces protected by nail varnish, 3 enamel specimens were mounted with wax in the lingual areas of a removable mandibular appliance. The study used a randomized, crossover design with seven subjects. In each of the 3 legs of the study, subjects wore the appliances continuously except when eating, drinking, and brushing their teeth. Twice daily (after breakfast and before bedtime), the subjects received a one-minute rinse with 20 mL of (1) 250-ppm-F NaF rinse, (2) 1000-ppm-F NaF rinse, or (3) 228-ppm-F two-solution F rinse. At the end of the 14-day experimental period, the sections were retrieved, and the mineral contents of the lesions were again assessed quantitatively. The results show that both the 1000-ppm-F NaF and 228-ppm-F two-solution rinses produced a greater (p < 0.05) remineralization than did the 250-ppm-F NaF rinse. The remineralization produced by the two-solution rinse was not statistically different (p > 0.05) from that produced by the NaF rinse with 4x the F content (1000 ppm F).

Analysis of Variance↗
PubMed2004

The remineralizing effect of an essential oil fluoride mouthrinse in an intraoral caries test.

BACKGROUND: The authors conducted a two-week clinical study to determine the remineralizing effect of an experimental mouthrinse containing both fluoride and essential oils in an intraoral caries test model. METHODS: The study used an observer-blinded, randomized, controlled, 3 x 3 crossover design. The authors enrolled in the study 153 subjects, each of whom had a mandibular removable partial denture. Two partially demineralized human enamel specimens were mounted on each subject's removable partial denture. Subjects used either a fluoride mouthrinse with essential oils (the test mouthrinse), a fluoride nonessential oils mouthrinse (the positive control) or an essential oil nonfluoride mouthrinse (the negative control) twice daily for 14 days. The researchers assessed specimens for mineral content change and fluoride uptake using surface microhardness, or SMH, testing and enamel fluoride analysis, respectively. RESULTS: Of the 153 subjects enrolled in the study, 125 subjects were evaluable at the study endpoint. The results after two weeks showed that percentage of SMH recovery was 42 percent in the test group, 36 percent in the positive control group and 16 percent in the negative control group. The fluoride uptake was 19 micrograms per square centimeter, 16 microg/cm2 and 3 microg/cm2 for the test mouthrinse, positive control and negative control groups, respectively. In terms of both percentage of SMH and fluoride uptake, the test mouthrinse and positive control mouthrinse were statistically higher than the negative control mouthrinse, and the test mouthrinse was "at least as good as" the positive control mouthrinse. CONCLUSIONS: This study provides evidence that an essential oil mouthrinse with 100 parts per million fluoride is effective in promoting enamel remineralization and fluoride uptake. CLINICAL IMPLICATIONS: The combination of fluoride and essential oils in a mouthrinse may provide anticaries efficacy, in addition to essential oils' previously established antigingivitis efficacy.

Cariostatic Agents↗
PubMed1998

The effect of root surface demineralization on bone morphogenetic protein-2-induced healing of rat periodontal fenestration defects.

The purpose of this study was to investigate the effect of acid conditioning of root surfaces during recombinant human bone morphogenetic protein-2 (rhBMP-2) induced periodontal regeneration in vivo. The buccal aspect of molar roots were denuded of their periodontal ligament through a bony window created in the mandible of 34 Wistar rats under general anesthesia. Three groups of 11 or 12 animals received either 10 microL of 50 g/mL rhBMP-2 in a collagen gel over the surgical defect (BMP) or 10 microL of collagen gel only (COL) or were left untreated (UN). Each of the 3 groups were further subdivided into those that received prior root acid conditioning with 35% phosphoric acid gel and those without acid conditioning. Animals were sacrificed 10 days after surgery and the tissues processed for histological examination. The BMP groups with and without acid conditioning developed significantly more bone over the second molar (3.89+/-0.86% and 7.62+/-0.93%, respectively; mean+/-SE), compared with the respective COL (1.24+/-0.26% and 2.77+/-0.52%) and UN groups (1.34+/-0.35% and 3.69+/-0.37%) (P <0.05). Furthermore, significantly more bone was found in the BMP non-acid conditioned group compared with all other groups (P <0.05). Acid conditioning promoted significantly more ankylosis (50%) compared with non-acid conditioning (6.3%) (P=0.007). New cementum formation was greatest in the BMP acid conditioned group (628.4+/-253.8 microm2) and lowest in the non-acid conditioned UN group (207.6+/-36.4 microm2) (P <0.05). This is the first known report evaluating the effects of root acid conditioning after a single application of rhBMP-2 in vivo. Results suggest that root conditioning agents operating at low pH administered into the periodontal wound impairs early BMP-induced osteogenesis while simultaneously promoting BMP-induced cementogenesis.

Analysis of Variance↗
PubMedDate not supplied

Demineralization effects of 2 bleaching procedures on enamel surfaces with and without post-treatment fluoride application.

In this in vitro study, the demineralization effect of 2 different bleaching procedures on enamel surfaces with and without the post-treatment application of fluoride was determined. Bovine enamel specimens (n= 180) were ground flat, polished and divided into 6 groups. Group A (n=30) specimens were bleached with Opalescence, 10% carbamide peroxide (Ultradent Products, Inc) for 8 hours daily for 2 weeks; Group B (n=30) specimens were treated with Whitestrips, 5.3% hydrogen peroxide (Procter & Gamble) for 1 hour daily for 2 weeks; Group C (n=30): the same as Group A, but after bleaching, a fluoride varnish was applied on the specimens and left for 1 hour (Duraphat, 2.26% F-); Group D (n=30): the same as Group B, followed by the same fluoride application as Group C; Group E (n=30): the specimens were covered with a glycerin gel as a control group; Group F (n=30): specimens were kept in Coca Cola 1 hour daily for 2 weeks. The mineral loss (vol% microm) and lesion depth (microm) were measured by microradiography. Data analysis was accomplished using the Kolmogorov-Smirnov, Kruskal-Wallis and Mann-Whitney U tests (p<0.05) (SPSS 11.0). The median mineral loss was statistically significantly higher in the non-fluoride groups (A: 271.20 vs C: 128.00 and B: 364.90 vs D: 151.10). The highest mineral loss was found in Group F (581.85 vol% microm) and was lowest in Group E (32.80 vol% microm). No statistically significant difference between groups was found for lesion depth.

Animals↗
PubMed1995

Intra-oral remineralization of enamel with a MFP/DCPD and MFP/silica dentifrice using surface microhardness.

The present study was undertaken to ascertain the effect of dicalcium phosphate dihydrate (DCPD) abrasive in a dentifrice on the remineralizaton of enamel using a surface microhardness technique. The method of assessing enamel remineralization via surface microhardness (SMH) was validated in a randomized, crossover, double-blind, intra-oral remineralization study conducted with 12 healthy adults. Enamel demineralization was achieved in vitro by covering bovine enamel blocks with exogenous oral bacteria, S. Mutans 1600 Ingbritt, containing glucan which was then exposed to sucrose. In the intra-oral treatment phase, subjects were fitted with oral maxillary palatal retainers, each holding four demineralized enamel blocks. Subjects brushed their teeth for 30 seconds with a test dentifrice, swished for an additional 60 seconds, rinsed with water and then retained the blocks intra-orally for 4 hours. Percent mineral recovery for each enamel block was calculated as the ratio of the changes in enamel microhardness due to treatment (remin) and sucrose challenge (demin). Treatments included DCPD-based dentifrices containing 0, 250 and 1000 ppm fluoride (F) from sodium monofluorophosphate (MFP). Using SMH, respective mean percent mineral recoveries of 5.7, 18.7 and 41.4% were obtained. All ADA criteria for model validation were fulfilled. This same model was then used to compare the remineralization effects of a silica placebo, DCPD placebo, 1000 ppm F MFP/silica and 1000 ppm F MFP/DCPD dentifrice. Mean percent mineral recoveries of -0.9, 24.1, 30.2 and 55.7% were obtained, respectively. The MFP/DCPD dentifrice was superior to MFP/silica (<0.01) with use of the MFP/DCPD dentifrice when compared to MFP/silica or the silica placebo. These results indicate that more active calcium and a higher degree of saturation (DS(EN)) with respect to enamel exists for an extended period of time after use of a MFP/DCPD dentifrice. Since an elevation in DS(EN) is considered a major parameter controlling the extent of enamel remineralization, this finding may partly explain the superior remineralization of enamel observed with the MFP/DCPD dentifrice. The significant increases in calcium activity and intra-oral enamel remineralization by the DCPD-based dentifrice are consistent with earlier findings that a DCPD abrasive provides added benefit for enamel remineralization.

Adolescent↗
PubMedDate not supplied

Prevention of artificial caries: effect of bonding agent, resin composite and topical fluoride application.

This study investigated the effect of fluoride containing resin composites and bonding agents, as well as the topical fluoride (F) application on the inhibition of artificial caries progression by using a pH-cycling model with alternating demineralizing (pH:4.5) and remineralizing (pH:7.0) solutions. Two bonding systems (F-containing bonding system [Reactmer Bond: RB] and non-F containing bonding system [Clearfil SE Bond: SE]), two resin composites, (F-containing [Reactmer Paste: RP] and non-F containing [Clearfil AP-X: AP]) were used. A combination of each bonding agent and a resin composite, RB+RP, RB+AP, SE+RP and SE+AP, was placed in 2 x 3 x 1.5-mm cavities on root dentin of extracted molars (n=96). Specimens were subjected to pH-cycling for 6 or 12 weeks. Half of all specimens were immersed in 0.05% NaF solution for 1 minute once a day as a topical F application. After the pH cycling period, a microradiograph of each specimen was taken, and the outer lesion depth of the artificial caries was measured by means of image analyzing software. The depths of the outer lesions at different periods were analyzed by one-way ANOVA and Sheffe's test at p=0.05. The combination that received F treatment showed reduced lesion depth compared to the same combination without F application. Except for the F application group of 12 weeks, there was no significant difference in lesion depth among each bonding and composite combination (p>0.05). At week 12 with the F application, RB+RP showed the shallowest lesion compared to the other combinations (p<0.05). The results indicated that the F application reduced the progression of artificial caries. Moreover, the combination of fluoride containing bonding agent and restorative material was the most effective for the inhibition of artificial caries progression based on the 12-week experimental period with topical F application.

Cariostatic Agents↗
PubMed1998

Reversal of incipient and radiographic caries through the use of sodium and stannous fluoride dentifrices in a clinical trial.

Experimental evidence has clearly demonstrated that the early stages of lesion formation (enamel demineralization) are reversible following exposure to saliva and/or fluoride. Clinical evidence for remineralization has also been reported extensively in the literature. However, the literature is lacking with respect to data from well-controlled clinical studies regarding the quantitative contribution of remineralization to arrestment and reversal of caries. Retrospective analysis of an existing clinical trial database provided an opportunity to examine the incidence of clinical lesion reversals in a placebo-controlled, double-blinded caries clinical study. The clinical study examined three treatment groups: 1) 0.243% sodium fluoride/silica dentifrice, 2) 0.4% stannous fluoride/calcium pyrophosphate (positive control) dentifrice and 3) non-fluoridated placebo/calcium pyrophosphate (negative control) dentifrice. Clinical measures in this study included both radiographic and visual-tactile assessments of caries. Examination of all subjects revealed a statistically greater frequency for caries reversals in the sodium fluoride group as compared to the placebo group at Year 3, for both total and radiographic caries. In contrast, while caries reversals in the stannous fluoride group occurred with greater frequency than in the placebo group at Year 3, for both total and radiographic caries, the differences were not statistically significant. When only subjects who were "at risk" for potential reversals (i.e., those with a minimum of one carious lesion at baseline) were examined, a statistically greater frequency in caries reversals was observed in both the sodium fluoride (total, incipient, and radiographic caries) and stannous fluoride (total and radiographic caries) groups as compared to the placebo group at Year 3. Collectively, these data confirm the ability of both 0.243% sodium fluoride/silica and 0.4% stannous fluoride/calcium pyrophosphate dentifrices to clinically reverse caries. The results suggest that sodium fluoride may deliver a greater frequency of caries reversals than stannous fluoride, although these treatments were not found to be significantly different.

Adolescent↗
PubMed2002

Effect of perfusion with water on demineralization of human dentin in vitro.

Dentinal fluid rarely features in caries studies of dentin. The mutual effects of in vitro perfusion and dentin demineralization were investigated. The correlation between the remaining dentin thickness and demineralization was also analyzed. Buccal cervical dentin windows in human tooth segments were demineralized either with or without perfusion with water at 3.14 kPa. Transverse microradiography revealed that dentin perfusion reduced the amount of mineral loss from the lesions by 22 vol%; the reduction in lesion depth was 8%. Perfusion rate, which was measured throughout the demineralization process by means of a fluid transport model, did not change significantly. Lesions formed closer to the pulp exhibited increased mineral loss and lesion depth. In conclusion, dentinal fluid flow offers some protection against demineralization. For a better approximation of clinical reality, therefore, in vitro studies on dentinal caries should consider the effect of dentinal fluid flow.

Analysis of Variance↗
PubMed1989

[Comparison of the chelating capacity of EDTA and EGTA, a new demineralized agent, on molars in vitro].

Recent morphologic studies have shown qualitative, how demineralizing substances clean teeth roots. In this work we attempt to describe quantitatively the "chelation process" and pH evolution of the quelator solution in-vitro inside the teeth during the reaction. These results indicate that Ca++ coming from hydroxyapatite release protons from EDTAH under neutral conditions. This is the most likely mechanism of the "self-limitation". Furthermore, it allow us to explain why EDTA Im and EGTA Im were more efficient than EDTA Na and EGTA Na upon demineralizing the tooth. EGTA Im turn out to be the fastest demineralizing agent as compared to EDTA Na which is currently employed in endodontic therapy.

Calcium↗
PubMed1996

Measurement of enamel demineralization using microradiography and confocal microscopy. A correlation study.

Substantial amounts of tooth minerals are lost during dental caries formation. Transversal microradiography, a well-accepted method used to quantify mineral loss, is a time-consuming technique which requires a thin enamel section (100 microns) and involves the use of x-rays. In an attempt to solve these difficulties, a procedure has been developed in which a human tooth specimen with demineralized enamel is cut in half (HT), stained with a fluorescent dye (rhodamine B) and analyzed using a laser scanning confocal microscope. A series of three studies was conducted to correlate measurements of enamel demineralization obtained from enamel thin (100 microns) sections (TS) using transversal microradiography with three parameters (area of the lesion; total and average dye fluorescence intensities) measured on the same TS or on a thicker section (HT) of the same specimen by laser scanning confocal microscopy. Results showed that a 0.1 mM rhodamine B solution provided the most adequate imaging conditions for confocal microscopy. Pearson's correlation coefficients, calculated between microradiography and confocal microscopy data obtained using a 0.1 mM rhodamine B solution, were: delta Z vs. HT lesion area = 0.95; delta Z vs. HT total fluorescence = 0.80; delta Z vs. HT average fluorescence = 0.74; delta Z vs. TS lesion area = 0.95; delta Z vs. TS total fluorescence = 0.74; delta Z vs. TS average fluorescence = 0.55. All these correlations coefficients were statistically significant (p < 0.01). It is concluded that in enamel demineralization studies statistically significant correlations exist between parameters measured using transversal microradiography and parameters quantified using confocal microscopy.

Analysis of Variance↗
PubMed1980

In vivo remineralization using a sustained topical fluoride delivery system.

The efficacy of a new remineralization system was determined in vivo by maintaining a low concentration of approximately 1 ppm fluoride for 48 hrs against a demineralized human tooth. Human subjects were selected who wore removable partial dentures containing two or more of the demineralized teeth with film system. The findings indicate levels of fluoride uptake to 500 ppm at 50 micron depths in experimental sites.

Delayed-Action Preparations↗
PubMed1989

Correlation between physical changes in tooth enamel and changes in iodide penetrability following in vitro or intraoral demineralization.

Demineralization of bovine tooth enamel was assessed by various physical means, and results were compared to measured changes in penetrability to iodide ions (delta Ip). Blocks of bovine enamel were exposed in vitro to lactate buffer (pH 4.3) containing 25 mM CaCl2 and 10 mM KH2PO4 for up to 4 days. Delta Ip increased over a wide range with time. A plot with respect to microhardness exhibited a pronounced inflection, with delta Ip rising rapidly at indentation depths greater than 2.5 microns. Microradiography and polarized light microscopy demonstrated subsurface lesions coincident only with the higher delta Ip values. The limited demineralization during the early time periods, therefore, was associated with only minimal changes at or near the enamel surface, yet could be detected readily with the delta Ip system. Demineralization produced intraorally in subjects rinsing with 5% sucrose was accompanied by increases in delta Ip, but no changes in surface microhardness or microscopic appearance of the enamel. It appeared that, under these conditions, demineralization was limited to the surface and corresponded to the very early phases of lesion formation.

Animals↗