Effectiveness for dentin hypersensitivity treatment of non-carious cervical lesions: a meta-analysis.

OBJECTIVE: The aim of this review is to conduct a systematic review and meta-analysis comparing the effectiveness of in-home or in-office treatments for dentin hypersensitivity. MATERIALS AND METHODS: An electronic search without restriction on dates or languages was performed in four electronic databases until March 2017. In addition, hand-searches in regular journals and in the gray literature were also conducted. To develop the search strategy, clinical questions were formulated using the PICOS method. Eligibility criteria included randomized clinical trials (RCTs) that compared the effectiveness of different agents for the treatment of dentin hypersensitivity through chemical occlusion, physical occlusion, nerve desensitization, or photobiomodulation (low-level light therapy). This systematic review was registered in PROSPERO under number CRD42016039394. RESULTS: Twenty-five RCTs (16 parallel; 9 split-mouth), published from 1992 to 2016, were included. The results of the meta-analysis showed that in-office subgroups treated with chemical or physical occlusion of dentin tubules and nerve desensitization had a statistically significant difference from placebo, with P < 0.00001, P < 0.00001, and P = 0.02, respectively. For in-home treatments, the results of the meta-analysis showed that only those subgroups treated with chemical occlusion of dentin tubules and nerve desensitization exhibited a statistically significant difference from placebo, with P < 0.00001 and P = 0.03, respectively. CONCLUSIONS: The results of pairwise meta-analysis suggest that among in-office treatments, dentinal tubule occlusion (whether chemical or physical) and nerve desensitization provide the best outcomes for treatment of dentin hypersensitivity. For in-home treatments, only chemical occlusion of dentin tubules and nerve desensitization showed a greater treatment efficacy than placebo and the difference was statistically significant.

Comparative evaluation of the remineralising effects and surface microhardness of glass ionomer cement containing grape seed extract and casein phosphopeptide - amorphous calcium phosphate: an in vitro study.

AIM: To evaluate and compare in vitro the remineralising effects and surface microhardness of glass ionomer cement (GIC), GIC containing grape seed extract and GIC containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). METHODS: An in vitro study with 45 mandibular premolars with standardised class V cavities prepared on the buccal and lingual surfaces. Artificial caries-like lesions were created and teeth were randomly divided into 3 groups of 15 teeth each. Each tooth was sectioned longitudinally into buccal and lingual halves; lingual half was used as control and the other as the test specimen. Axial longitudinal sections of the control specimens were analysed under polarised light microscopy. The experimental halves were restored with 3 materials. Group I: glass ionomer cement (GIC), Group II: 10% (w/w) grape seed extract and GIC (GSGIC), Group III: 10% (w/w) casein phosphopeptide-amorphous calcium phosphate (Recaldent) and GIC (CPPGIC). The restored tooth specimens were exposed to pH cycling for 28 days and analysed again for remineralisation under polarised microscopy. For the second part of the study, 60 cylindrical specimens (20 each) were made using standardised brass moulds and the three experimental materials. The specimens were immersed individually in de-ionised water. After 7 days of immersion, 10 specimens from each group were subjected to microhardness measurements and repeated on the remaining specimens at the end of 30 days. STATISTICS: One way ANOVA and post-hoc Tukey's test were used for statistical analysis. RESULTS: CPPGIC showed the greatest remineralisation followed by GSGIC and least for GIC. Comparisons of microhardness between the three groups were not statistically significant. CONCLUSION: Grape seed extract and CPPACP can be used for remineralisation of damaged dentine and their incorporation into GIC does not compromise the microhardness properties significantly.

Effects of different amine fluoride concentrations on enamel remineralization.

OBJECTIVES: The aim of this study was to investigate the effects of decreasing fluoride concentrations on repeated demineralizing challenges on human enamel. MATERIALS AND METHODS: In 24 teeth, 3mm×3mm windows were prepared on the buccal and lingual sides and treated in a cycling demineralization-remineralization model. Remineralization was achieved with 100, 10 and 0.1 ppm fluoride from anime fluoride. Coronal sections were cut through the artificial lesions, and three sections per tooth were investigated using polarized light microscopy and scanning electron microscopy with quantitative element analysis. RESULTS: The morphology of the lesions was studied, and the extensions of the superficial layer and the body of the lesion were measured. Using element analysis, the Ca, P and F content were determined. The body of the lesion appeared remineralized after application of 100 ppm fluoride, while remineralization of the lesion was less successful after application of 10 and 0.1 ppm fluoride. The thickness of the superficial layer increased with decreasing fluoride concentrations, and also the extension of the body of the lesion increased. Ca and P content increased with increasing fluoride concentrations. CONCLUSIONS: The effectiveness of fluoride in enamel remineralization increased with increasing fluoride concentration. CLINICAL RELEVANCE: A consistently higher level of fluoride in saliva should be a goal in caries prevention.

An in vitro model for the study of chemical exchange between glass ionomer restorations and partially demineralized dentin using a minimally invasive restorative technique.

OBJECTIVES: This study was designed to validate an in vitro model of the Atraumatic Restorative Technique (ART). This model allowed in depth analyses of the migration of apatite forming Sr and F, from a glass-ionomer, Fuji IXGP (GC Corporation, Tokyo, Japan), into partly demineralized dentine. The second objective was to study the effects of the levels of mineral loss on such ionic exchange. METHODS: Artificial lesions were created in thirty third molars, which were divided into three groups based on time of exposure to the demineralizing solution (7, 14 and 21 days). These were restored with Fuji IXGP and left for 21 days. The method of analysis was electron probe microanalysis (EPMA) with wavelength dispersive spectrometry (WDS). This combination can yield both qualitative identification of elements as well as quantitative compositional information, with a minimum detection limit of 0.01%. RESULTS: The results indicated that there was no significant difference in the levels of Ca and P from the control and test sides for all three groups of demineralized dentine. The differences in the depth of penetration and the amount of Sr and F between control and test were significant. CONCLUSIONS: The validity of the in vitro model was confirmed. There was migration of both strontium and fluorine to the artificially demineralized dentine in a pattern consistent with remineralization and similar to what was observed in a previous in vivo study.

An in vitro evaluation of selective demineralised enamel removal using bio-active glass air abrasion.

Unnecessary over-preparation of carious enamel often occurs clinically during operative caries management. The working hypothesis to be investigated in this study is the potential for bio-active glass air abrasion to remove selectively only demineralised enamel in artificial enamel lesions when compared to equivalent alumina air abrasion, so potentially minimising cavity over-preparation. Bisected artificial, paired smooth surface enamel lesions on ethics-approved, extracted sound human molars were created and subsequently air abraded with 27 µm alumina (n = 19) and bio-active glass (n = 19). The difference between pre-operative lesion boundary and post-operative cavity margin was calculated following optical confocal fluorescent assessment of the lesion boundary. Data indicated mean% over-preparation (sound enamel removal) of 176% with alumina and 15.2% for bio-active glass (p = 0.005). Bio-active glass abrasion removed completely the demineralised enamel from artificial lesions with clinically insignificant over-preparation of sound tissue, indicating technique selectivity towards grossly demineralised enamel. Alumina air abrasion resulted in substantial enamel removal in both sound and demineralised tissues indicating the operator selectivity required to use the techniques effectively in clinical practice.

Minimally invasive caries removal using bio-active glass air-abrasion.

OBJECTIVES: Alumina air-abrasion has been used to clean teeth and shown to over-prepare access cavity preparation to caries. This study investigated the working hypothesis that bio-active glass air-abrasion is more self-limiting than alumina for minimally invasive caries removal. METHODS: Human extracted molars were scored visually using ICDAS II criteria, divided into sound and carious groups and air-abraded with alumina (n=10) and bio-active glass (n=10) in each group, using identical operating parameters. The amount of enamel removed was semi-quantitatively assessed using scanning electron microscopy. Operating time was recorded. RESULTS: Bio-active glass abrasion removed extrinsic stain and substantial quantities of enamel from all carious fissures but not from sound, where only minimal microscopic surface modifications were observed. Alumina air-abrasion resulted in faster extrinsic stain and clinically substantial enamel removal in both sound and carious groups equally. CONCLUSIONS: Bio-active glass air-abrasion appeared to show a significant self-limiting tendency towards demineralised enamel and extrinsic stain removal but was slower in comparison to alumina air-abrasion. Self-limiting bio-active glass air-abrasion could be used clinically to clean teeth, detect caries and minimally prepare carious enamel as part of MI caries access or placing a sealant restoration.

A preliminary study of enamel remineralization by dentifrices based on RecaldentTM (CPP-ACP) and NovaMin® (calcium-sodium-phosphosilicate)

The purpose of this study was to investigate the enamel remineralization potential of two toothpastes, one of which was based on RecaldentTM (CPP- ACP) and the other on NovaMin® (Calcium-sodium-phosphosilicate). Human permanent molar teeth were subjected to three consecutive demineralization cycles. These cycles were followed by remineralization of the experimental groups by toothpastes containing RecaldentTM and NovaMin® respectively. The samples were analyzed by Scanning Electron Microscope, (SEM) and energy-dispersive X-ray spectroscopy analysis (EDX). Extensive demineralization was noted in the control group (without remineralization) while the groups treated with the dentifrices demonstrated various degrees of remineralization, as shown by formation of different types of deposits on the enamel surface. The EDX analysis showed increased amounts of Ca, P, Si and Zn in the enamel of the experimental groups, compared to the control one. Toothpastes containing RecaldentTM and especially NovaMin® have the potential to remineralize enamel, a property which might be important in finding a substitute to pit and fissure sealing.

El objetivo del trabajo fue investigar el potencial de remineralizacion del esmalte de dos pastas dentifricos, una de ella con formulacion basada en RecaldentTM (CPP- ACP) y la otra en NovaMin® (phosphosilicato de calcio y sodio). Se realizaron tres ciclos cosecutivos de desmineralizacion en molares permanentes humanos, seguidos de remineralizacion, en los grupos experimentales con los denti fricos que contenian RecaldentTM y NovaMin® respectivamente. Se analizaron las muestras con microscopia electronica de barrido (SEM) y analisis espectroscopico por dispersion de rayos X (EDX). En el grupo control (sin remineralizacion) se observo una extensa demineralizacion mientras que los grupos tratados con los dentifricos mostraron varios grados de remineralizacion, evidenciados por la formacion de diferentes tipos de depositos sobre la superficie del esmalte. El analisis EDX mostro cantidades aumentadas de Ca, P, Si y Zn en los grupos tratados en comparacion con el grupo control. Los dentifricos conteniendo RecaldentTM y especialmente Nova- Min®, tienen potencial de reminalizacion del esmalte, una propiedad que puede resultar importante como substituto del sellado de fosas y fisuras.

A preliminary study of enamel remineralization by dentifrices based on Recalden (CPP-ACP) and Novamin (calcium-sodium-phosphosilicate).

The purpose of this study was to investigate the enamel remineralization potential of two toothpastes, one of which was based on Recaldent (CPP- ACP) and the other on NovaMin (Calcium-sodium-phosphosilicate). Human permanent molar teeth were subjected to three consecutive demineralization cycles. These cycles were followed by remineralization of the experimental groups by toothpastes containing Recalden and NovaMin respectively. The samples were analyzed by Scanning Electron Microscope, (SEM) and energy-dispersive X-ray spectroscopy analysis (EDX). Extensive demineralization was noted in the control group (without remineralization) while the groups treated with the dentifices demonstrated various degrees of remineralization, as shown by formation of different types of deposits on the enamel surface. The EDX analysis showed increased amounts of Ca, P Si and Zn in the enamel of the experimental groups, compared to the control one. Toothpastes containing Recalden and especially NovaMin have the potential to remineralize enamel, a property which might be important in finding a substitute to pit and fissure sealing.

In situ evaluation of the remineralizing capacity of pit and fissure sealants containing amorphous calcium phosphate and/or fluoride.

OBJECTIVE: This in situ study evaluated the remineralizing potential of pit and fissure sealants containing amorphous calcium phosphate (ACP) and/or fluoride in artificially induced carious lesions on smooth enamel surfaces. MATERIAL AND METHODS: Ten volunteers who wore acrylic palatal devices were enrolled in this 5-day double-blind study and assigned to one of the following five groups: (I) demineralized enamel slab+Fluroshield (sealant with fluoride); (II) demineralized enamel slab+Aegis (sealant with ACP); (III) demineralized enamel slab+experimental sealant with fluoride (ESF); (IV) demineralized enamel slab+experimental sealant with fluoride/ACP (ACP-F); and (V) demineralized enamel slab (control). After the experimental period, the percentage of surface microhardness recovery (%SMHR) and the integrated loss of subsurface hardness (DeltaKHN) were evaluated. The concentrations of fluoride, calcium and phosphorus in enamel were also determined. RESULTS: The sealants containing ACP and/or fluoride presented a higher remineralizing capacity (%SMHR and DeltaKHN) than that of the control group. Aegis provided either more efficient or similar remineralization than the other sealants. The association between ACP and fluoride did not show a greater efficacy in the remineralization. F, Ca and P concentrations in enamel varied according to the group. CONCLUSION: The pit and fissure sealants containing ACP were able to promote remineralization of artificially induced carious lesions on smooth enamel surfaces.

In vitro evaluation of enamel remineralisation by a casein phosphopeptide-amorphous calcium phosphate paste.

PURPOSE: The aim of this preliminary in vitro study was to evaluate the effect of a casein phosphopeptide and amorphous calcium phosphate (CPP-ACP) paste on untreated enamel surfaces that had previously been exposed to an erosive challenge. MATERIALS AND METHODS: Over a period of 6 h, enamel samples from five fully erupted, caries-free molars were incubated with apple juice and later covered with CPP-ACP paste for 15 min. Enamel samples incubated with physiological sodium chloride solution or with apple juice alone served as controls. The quantitative elementary analysis for calcium and phosphorus in various depths ranging from 5 to 50 microm was performed using an electron-probe microanalyser. RESULTS: Exposure to apple juice resulted in a loss of minerals down to a depth of 30 microm with a mean loss of 13% at 5 microm and 6% at 10 microm. After treatment with CPP-ACP paste, the mineral loss decreased to a mean of 9% at 5 microm and remained at 5% at a depth of 10 microm (not a statistically significant difference). At a depth of 20 microm, no further mineral loss was recorded. CONCLUSIONS: This study demonstrated that there is a slight gain in the mineral contents after the application of a CPP-ACP paste, mainly in the upper enamel layer. Within the limitations of this in vitro study, the application of CPP-ACP paste may enhance the remineralisation after an erosive challenge and thus offer some protection for patients who are at risk for erosion.

In vitro evaluation of dentifrice with low fluoride content supplemented with trimetaphosphate.

One way to reduce dental fluorosis is by reducing the fluoride (F) concentration in dentifrice, but low-F dentifrice should be as effective as a standard dentifrice. This study evaluated in vitro whether the supplementation with sodium trimetaphosphate (TMP) of a dentifrice with low F content (500 microg/g) would provide a similar effect to that of a standard dentifrice. Bovine enamel blocks were submitted to a pH cycling regime incorporating daily exposures to a slurry of dentifrice: a low-F dentifrice with or without 0.1-3.0% TMP; an F-free, phosphate-free dentifrice (negative control), or a dentifrice with 1,100 microg/g F (positive control). The addition of TMP to dentifrice with or without F was associated with higher surface hardness and decreased loss of integrated subsurface hardness after pH cycling. The combination of 1% TMP and 500 microg F/g had a greater effect than the positive control dentifrice. It is concluded that the addition of TMP to the 500-microg F/g dentifrice allowed a similar or larger effect as compared with a standard dentifrice in this in vitro model.

Effect of various calcium/phosphates ratios of carboxymethylcellulose-based saliva substitutes on mineral loss of bovine enamel in vitro.

OBJECTIVES: The present study evaluated the effects of various calcium and phosphate concentrations and ratios of carboxymethylcellulose (CMC)-based solutions on the mineral loss of predemineralised bovine enamel in vitro. METHODS: Bovine enamel specimens were prepared, polished and partly covered with nail varnish, thus serving as control of sound enamel. After demineralisation (37 degrees C; pH 5.0; 14 days) the specimens were exposed to CMC-based solutions (20g/l) with various saturations with respect to apatites containing 0.1mM NaF, CaCl2 (0-32 mM) and KH2PO4 (0-52 mM) at two different pH values (5.5 or 6.5). A fluoride-free solution served as control, and four commercially available products were tested as well. The differences in mineral loss (DeltaDeltaZ) between the values prior to (DeltaZ Demin) and after storage (DeltaZ Effect) in the various solutions were evaluated from microradiographs of thin sections (100microm). RESULTS: The general linear model revealed a significant dependency for DeltaDeltaZ on 'calcium' (p<0.001), 'phosphate' (p=0.023), 'fluoride' (p=0.002) and 'pH' (p<0.001). With increasing calcium and phosphate concentrations an increase in DeltaDeltaZ could be observed up to the solution containing the third highest saturation with respect to octacalciumphosphate (3.2), showing a significant remineralisation (p<0.05; t-test). The commercially available products as well as the control groups revealed significantly reduced DeltaDeltaZ values compared to this group (p<0.01; Bonferroni). CONCLUSIONS: A saturation with respect to octacalciumphosphate of 3.2 and a pH of 6.5 enables CMC-based solutions to remineralise bovine enamel in vitro.

Linseed based saliva substitutes and their effect on mineral dissolution of predemineralized bovine dentin in vitro.

OBJECTIVES: Polymers used in saliva substitutes might inhibit remineralization. The present study evaluated the effects of various calcium, phosphate, and fluoride concentrations of linseed based solutions on the mineral loss of predemineralized bovine dentin in vitro. METHODS: Dentin specimens were prepared, embedded and polished. The specimens were demineralized (pH 5.6; 6 d; 37 degrees C) and half of each sample was covered with nail varnish. Subsequently, the specimens (n=10) were exposed to 14 linseed based solutions (calcium 0-1.1 mM; phosphate 0-7.7 mM, fluoride 0-0.03 mM) at pH 5.5 and 6.5 as well as to Salinum for 14 days (37 degrees C). The differences in mineral loss (DeltaDeltaZ) between the values prior to and after storage in the solutions were evaluated from microradiographs of thin sections. RESULTS: After the exposure to the various solutions decreased mineral contents compared to those after demineralization could be observed (p<0.05; paired t-test) whereas for the specimens stored in solution with the highest calcium and phosphate concentration no significant change in mineral loss could be evaluated (p>0.05). Salinum induced a significantly greater mineral loss compared to the equivalent saturated solution (p<0.05; ANOVA, Bonferroni). The general linear model revealed a significant dependency for DeltaDeltaZ on 'phosphate' (p=0.000) and 'fluoride' (p=0.001), but not on 'calcium' (p=0.397) and 'pH' (p=0.368). CONCLUSIONS: The addition of calcium, phosphates, and fluorides seems to have a positive effect on the remineralizing qualities of linseed based saliva substitutes.

Effect of Er:YAG laser and organic matrix on porosity changes in human enamel.

OBJECTIVES: Cariostatic effects of lasers have been well documented in the past few decades; however, the mechanisms remain unclear. Our previous study revealed the statistically significant effect of organic matrix (OM) in the laser-induced caries prevention. The aim of the present study is to further investigate the role of organic matters in the laser-induced porosity changes. METHODS: Enamel powder from five sound molars was randomly divided into two samples. One sample was treated with approximately 10% NaClO solution to remove OM and the other was left untreated. Both groups were then subjected to irradiation by an Er:YAG laser. The samples were characterized by thermogravimetric analysis (TGA) and N(2) physico-adsorption. RESULTS: TGA results confirmed that the NaClO treatment had at least partially removed the OM in enamel powder. The surface area and pore volume of normal enamel powder decreased significantly after laser treatment. In contrast, in the NaClO-treated enamel powder, laser treatment did not significantly decrease the surface area and the pore volume remained almost unchanged. The substantial difference between the normal enamel powder and the NaClO-treated enamel powder after laser treatment confirmed the laser-induced blocking of OM in the micro-diffusion pathway in enamel. CONCLUSION: The findings in this study seemed to substantiate the "organic blocking theory" as one of the mechanisms in the laser-induced caries prevention.

Physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination in vivo.

This study evaluated the physiological remineralization of artificially demineralized dentin beneath glass ionomer cements with and without bacterial contamination. The artificially demineralized dentin was produced on 84 monkey teeth using a decalcifying solution. Half the samples were left open to the oral cavity for one week, then, all cavities were restored with two glass-ionomer cements: Fuji IX or Fuji II LC improved (n = 7). The nanohardness of the artificially demineralized dentin at 3, 90 and 360 days was measured using a nanoindentation tester (ENT-1100, Elionix) and compared statistically by two-way ANOVA and Fisher's PLSD test (p < 0.05). Each mineral (Ca, Mg, P, F) within the demineralized dentin was also analyzed using Electron Probe Microanalysis. For the samples, the mean nanohardness of the three-day samples was significantly lower than the 360-day samples (p < 0.05). Although there was no significant difference in the mean nanohardness within all the bacterially-contaminated groups through the experimental periods (p > 0.05), the mean nanohardness of the bacterial-contaminated samples were significantly lower than the non-bacteria-contaminated samples (p < 0.05). From the EPMA results, fluoride release from both cements to the bottom of the artificially demineralized dentin was detected within three days. Although Ca density was sparse within this demineralized dentin lesion, for the Fuji IX sample, a high Mg density within this lesion was detected at 360 days.

Dental treatment, dental fear and behaviour management problems in children with severe enamel hypomineralization of their permanent first molars.

OBJECTIVES: To assess the demand for restorative treatment, dental anxiety and dental behaviour management problems among children with severe hypomineralization of their first molars (MIH). DESIGN: Case control study. SAMPLE AND METHODS: Data were compiled from the dental records of 32 9-year-old children with severe enamel hypomineralization of their first molars and from 41 controls of the same age group concerning dental health, a number of restorative treatments, use of local anaesthesia and clinical behaviour management problems (BMP). A questionnaire containing specific questions on children's experiences of dental care and the Children's Fear Survey Schedule-Dental Subscale (CFSS-DS), was answered by the parents. RESULTS: The children in the study group had undergone dental treatment of their first molars nearly 10 times as often as the children in the control group. Repeated treatments of these teeth at brief intervals were common. The dental treatment was often undertaken without the use of local anaesthesia, and BMP, and dental fear and anxiety (DFA) were more common than in the controls. CONCLUSIONS: Children with severe enamel hypomineralization of their first molars had had to undergo a considerable amount of dental treatment. It is reasonable to assume that experiences of pain and discomfort on repeated occasions were related to the occurrence of BMP in patients with MIH. An early treatment planning and prognostication based on increased knowledge of hypomineralized first molars is desirable. Local anaesthesia and other pain-reducing techniques, e.g. sedation, should be used when treating these teeth. Extraction should be considered in cases of extensive disintegration of the crown, in cases of frequently repeated treatments or when pulpal symptoms are hard to cure.

In vivo diagnostic assessment of dentinal caries by junior and senior students using red acid dye.

The aim of this study was firstly to determine and compare the ability of inexperienced junior dental students (Fourth-year) and senior students (Fifth-year) versus a dental school instructor to identify demineralized dentine with the aid of a caries-disclosing solution and secondly to evaluate an eventual improvement of the caries diagnosis accuracy of junior (Fourth-year) and senior (Fifth-year) dental students. Three successive stages were used to check the ability of the dental students to diagnose and excavate the de-mineralized dentine. This study pointed out that 96% of junior dental students versus a teacher failed to remove all of the demineralized dentine without the use of a caries detector at the first stage and 79% at the second stage in the same condition. 100% of senior students versus a teacher, also failed to diagnose dental caries without a caries detector, but only at the first stage. However, at the second stage, unlike the junior students, all of the senior students were able to remove all of the demineralized dentine. Without the use of a caries detector dye, the risks of the dental students leaving demineralized dentine are high. This technique may be particularly helpful for the fourth-year students who are performing their first restorative treatment.

Remineralization by fluoride enhanced with calcium and phosphate ingredients.

The effectiveness of fluoride ions provided by toothpastes and mouthrinses in promoting remineralization can be limited by the low concentrations of calcium and phosphate ions in saliva. The purpose of this study was to determine whether improved remineralization can be obtained from toothpastes or mouthrinses that simultaneously deliver fluoride, calcium, and phosphate ions from dual-dispensing systems. Enamel specimens with artificial lesions between 60 and 90 microns deep were cycled 15 times through demineralization for 30 minutes, treated for 5 minutes with an experimental or control fluoride toothpaste or mouthrinse, and remineralized for 60 minutes. In the toothpaste study, surface hardness increased by 11.5 +/- 9.2 and 2.7 +/- 3.6 Vickers hardness units, and enamel fluoride content was 5984 +/- 521 ppm and 3971 +/- 531 ppm for the experimental and control fluoride toothpastes, respectively. Remineralization was confirmed by x-ray microradiography. In the mouthrinse study, surface hardness increased by 8.8 +/- 7.7 and 2.2 +/- 3.7 Vickers hardness units, and enamel fluoride content was 6111 +/- 1078 ppm and 3160 +/- 364 ppm for the experimental and control fluoride mouthrinses, respectively. Use of a non-fluoride control mouthrinse led to a decrease in surface hardness of 3.7 +/- 5.2 Vickers hardness units despite a fluoride content of 402 ppm. The results demonstrate that calcium and phosphate supplementation in a toothpaste or mouthrinse can improve remineralization and increase fluoride uptake.

Laser fluorescence quantification of remineralisation in situ of incipient enamel lesions: influence of fluoride supplements.

The aims of this study were to test the laser fluorescence method for quantification of remineralisation in situ of enamel with incipient lesions and to evaluate the enhancement of remineralisation by fluoride (F) supplements when a F dentifrice was used on a regular basis by healthy young subjects. Enamel samples were cut from extracted premolar teeth with the natural surface kept intact, and subjected to a pH-cycling system to produce subsurface demineralisation in vitro. The enamel blocks were then inserted into composite holders bonded to the buccal surfaces of both upper first molars of 12 panelists. Each panelist participated in 3 separate experiments in a randomised order; each lasted for 5 weeks with washout intervals of 2 weeks between experiments; experiment 1: F dentifrice (0.145% F as NaF) only; experiment 2: F dentrifice + F lozenges (0.25 mg F x 6/day); experiment 3: F dentifrice + F chewing-gum (0.25 mg F x 6/day). Fluorescence radiance was measured before, during, and after in vitro demineralisation, and once a week during the in situ experimental periods. The enamel samples were then sectioned and analysed with transverse microradiography (TMR). Anova and Pearson correlation coefficient were used for the statistical analysis. At the end of the 5-week in situ periods, fluorescence radiance had been regained to a level of 80-100% of the value before in vitro demineralisation, indicating remineralisation of the enamel samples. There were no differences in the fluorescence radiance gain between the 3 different F exposures. However, there was a statistically significant time trend (p < 0.001), and a highly significant linear dependence (p < 0.001) between the final measurements obtained with the laser fluorescence method (LAF) and the data obtained from TMR, r = 0.76. It was concluded that: (1) with the sensitive LAF method it was possible to register the small changes in the enamel week by week during in situ remineralisation: (2) when F dentrifice was used regularly, F supplements such as F lozenges or F chewing-gum did not significantly enhance the in situ remineralisation of incipient enamel lesions in healthy, young adults with normal salivary flow.

The effect of fluoridated milk on human dental enamel in an in vitro demineralization model.

Fifty-seven sound human permanent premolars were demineralized for 14 days and then exposed to six different treatments: group 1, 1 mg/1 fluoride in milk for 7 days; group 2, 1 mg/l fluoride in milk for 14 days; group 3, 10 mg/l fluoride in milk for 7 days; group 4, 10 mg/l fluoride in milk for 14 days; group 5, control non-fluoridated milk for 14 days, and group 6, control tap water for 14 days. Enamel etch samples were taken and analysed for fluoride and for phosphorus. An increase in the enamel surface fluoride content was observed in groups 1-3. A statistically significant elevation (p < 0.01) of fluoride content and a significant decrease (p > 0.001) of acid solubility were found only in group 4.