Acidulated Phosphate Fluoride Gel Application Research Articles

CO2 laser irradiation combined with fluoridated dentifrice improved its protective effect on caries lesion progression regardless of the acidulated phosphate fluoride gel application: An in situ study.

This in situ study aimed to investigate the efficacy of CO2 laser at a 10.6-µm wavelength combined with 1.23% acidulated phosphate fluoride (APF) and fluoridated dentifrice with 1100µg F/g (FD) to control enamel caries progression. Sixteen volunteers wore palatal appliances containing eight demineralized enamel specimens for four 14-day phases under sucrose exposure. These specimens were submitted to CO2 laser irradiation and APF alone or combined with FD. Treatment groups were non-fluoridated dentifrice-NFD, NFD + CO2 laser, NFD + APF, NFD + CO2 laser + APF, FD, FD + CO2 laser, FD + APF, and FD + CO2 laser + APF. Mineral loss, calcium fluoride (CaF2), fluorapatite (FAp), and fluoride in the biofilm were analyzed by analysis of variance followed by the Student-Newman-Keuls test, p < 0.05. The highest mineral loss inhibition was noted when FD and CO2 laser irradiation were combined, which did not significantly differ from the FD + CO2 laser + APF group. The CaF2, FAp, and F in the biofilm were more pronounced when the FD and APF were combined. The CO2 laser irradiation promoted a slightly higher concentration of CaF2 in the enamel and F in the biofilm. Although APF promotes the high formation of CaF2 and FAp, the combined use of FD with CO2 laser overcomes the APF effect in inhibiting the progression of artificial caries-like lesions in situ. Under the in situ design of this study, remineralization of white spot lesions was achieved through CO2 laser irradiation and daily use of fluoridated dentifrice. Future clinical trials are encouraged to substantiate this finding.

&lt;strong&gt;The effect of acidulated phosphate fluoride (APF) gel against erosion on enamel microstructure of primary teeth which soaked with Citrus aurantifolia &lt;/strong&gt;

ABSTRACTIntroduction: Erosion is a common dental problem that is especially prevalent in children due to the increasing consumption of acidic food and beverages. APF gel is believed to be effective in reducing the demineralization effect of the teeth as well as escalating the remineralization process. This research aims to determine and evaluate the effectiveness of 1.23% APF gel as a preventive agent for the erosion of tooth enamel, specifically in deciduous teeth. Methods: This type of research is true experimental research. The population of this research would be primary teeth extracted from children, using a purposive sampling technique with inclusive and exclusive criteria. A total amount of 5 maxillary primary central incisors were extracted and cleaned. APF gel was applied repetitively on the left side of the teeth for 4 minutes every hour, whereas the right side was left as it is. Samples were then analyzed using a scanning electron microscope (SEM). A qualitative and subjective analysis regarding the micromorphological features of the erosion can be done. Result: The side of teeth without APF gel application has a greater erosion rate compared with teeth with APF gel application. The tooth which is demineralized shows a honeycomb structure of the interprismatic enamel. As for the dentinal tubules, teeth without APF gel application have a bigger opening of dentinal tubules, going up to 7.868 micrometers in size compared to teeth with APF gel application (1-2 micrometers). Conclusion: The application of professional acidulated phosphate fluoride (APF) gel on deciduous teeth even when soaked in Citrus aurantifolia, is proven to be effective in preventing dental erosion.Keywords: acidulated phosphate fluoride (APF) gel; citrus aurantifolia; dental erosion; primary tooth

Effect of Er:YAG Laser Irradiation and Acidulated Phosphate Fluoride Therapy on Re-Mineralization of White Spot Lesions.

Statement of the Problem: Studies on the efficacy of erbium laser for enhancement of enamel resistance to acid attacks and its effects on fluoride uptake by the enamel are limited.Purpose: This study sought to assess and compare the effects of erbium-doped yttrium aluminum garnet (Er:YAG) laser irradiation and application of acidulated phosphate fluoride (APF) gel (alone and in combination) on remineralization of artificial white spot lesions (WSLs).Materials and Method: This in vitro, experimental study evaluated 90 buccal and lingual slabs of extracted human premolars. The specimens underwent pH cycling to induce WSLs. They were then randomly divided into 6 groups of caries-free positive control (c+), negative control with WSLs (ws), 1.23% APF gel applied on the enamel (F), Er:YAG laser irradiation (80 mJ, 10 Hz, and 8 J/cm2) of enamel (L), APF gel application followed by laser irradiation (FL), and laser irradiation followed by fluoride gel application (LF). The fluoride ion content of specimens was measured before and after the intervention using a potentiometer. Data were analyzed by ANOVA (p< 0.05).Results: APF gel application before/after laser irradiation maximally increased the fluoride uptake by the enamel (p= 0.000). Application of APF gel in group F and laser irradiation in group L increased fluoride uptake by the enamel, compared with groups 1 and 2 (p= 0.000). Laser- treated (L) and APF-treated (F) groups had no significant difference in this respect (p= 0.945). Maximum fluoride concentration was noted in combined laser and fluoride groups (FL=332.07ppm and LF=341.27ppm) with no significant difference between the two (p= 1.000).Conclusion: Er:YAG laser irradiation changes the chemical composition of enamel and probably promote its remineralization, especially when combined with APF gel application, which highlights its cariostatic potential.

THE EFFECT OF SURFACE COATING AGENT ON THE SURFACE ROUGHNESS OF RESTORATIVE MATERIALS EXPOSED TO ACIDULATED PHOSPHATE FLUORIDE

Aim: The aim of the study was to assess the surface roughness of six different restorative materials when they were covered with surface coating agent prior to 1.23% acidulated phosphate fluoride gel application. Materials and methods: Six restorative materials (Fuji IX, Amalgomer CR, Dyract XP, Beautifil II, ACTIVA, Filtek Z250) were used in this study. 28 specimens were prepared from each material and randomly divided into 4 groups (n=7) according to surface treatment regimens. Group C: control, no application, Group F: only acidulated phosphate fluoride gel application, Group S: only surface coating agent application, Group SF: surface coating agent prior to the acidulated phosphate fluoride gel application. The surface roughness values for all specimens were measured using profilometer. The results were statistically analyzed using analysis of variance (ANOVA), Newman Keuls and Tukey’s tests (p<0.05). Results: There were no statistically significant differences in surface roughness between group C and F for all analyzed materials, except for Amalgomer CR (p>0.05). The group C of Amalgomer CR showed higher surface roughness values than that of the group F (p=0.001). Group S produced significantly smoother surfaces than the group C for all restorative materials, except Dyract XP (p=0.001). Conclusion: 1.23% acidulated phosphate fluoride gel application did not promote a significant increase on the surface roughness of restorative materials whether or not surface coated. However, surface coating was found to produce smoother surfaces. Keywords: Fluoride gel, Glass ionomer cement, Surface roughness ASİDÜLE FOSFAT FLUORİD UYGULANAN RESTORATİF MATERYALLERİN YÜZEY PÜRÜZLÜLÜĞÜNE YÜZEY ÖRTÜCÜ AJANININ ETKİSİ ÖZ: Amaç: Bu çalışmanın amacı, %1,23 asidüle fosfat fluorid jel uygulamasından önce yüzey örtücü ajanı ile kaplanan altı farklı restoratif materyalin yüzey pürüzlülüğünün değerlendirilmesidir. Gereç ve yöntem: Çalışmada altı restoratif materyal (Fuji IX, Amalgomer CR, Dyract XP, Beautifil II, ACTIVA, Filtek Z250) kullanıldı. Her bir materyalden 28 örnek hazırlandı ve yüzeye yapılan uygulamalara göre rastgele 4 gruba ayrıldı (n=7). Grup K: kontrol, herhangi bir uygulama yapılmadı, Grup F: sadece asidüle fosfat fluorid jel uygulandı, Grup S: sadece yüzey örtücü ajan uygulandı, Grup SF: asidüle fosfat fluorid jel uygulanmadan önce yüzey örtücü ajan uygulandı. Tüm örneklerin yüzey pürüzlülüğü değerleri profilometre ile belirlendi. Sonuçların analizi varyans analizi (ANOVA), Newman Keuls ve Tukey testi ile yapıldı (p<0.05). Bulgular: Amalgomer CR dışındaki materyallerde, grup K ve grup F arasında yüzey pürüzülülüğü açısından istatistiksel olarak anlamlı farklılık görülmemiştir (p>0,05). Amalgomer CR’nin K grubu, F grubuna göre daha yüksek yüzey pürüzülülük değeri vermiştir (p=0,001). Dyract XP dışındaki tüm restoratif materyallerde grup S, grup K’ya göre anlamlı derecede daha pürüzsüz yüzey değeri göstermiştir (p=0,001). Sonuç: %1,23 asidüle fosfat fluorid jel uygulaması, yüzey örtücü uygulanmış ve uygulanmamış restoratif materyallerin yüzey pürüzlüğünde önemli bir artış sağlamamıştır. Ancak, yüzey örtücü uygulaması, materyallerin yüzey pürüzlülüğünü azaltmıştır. Anahtar kelimeler: Fluorid jel, Cam iyonomer siman, Yüzey pürüzlülüğü

The color improvement of postdebonding white spot lesions after fluoride and casein phosphopeptide- amorphous calcium phosphate application.

White spots are common side effects of orthodontic treatment, and their presence after debonding appears unesthetic. This study aimed to quantify and compare the visual improvement in postdebonding white spot lesions following fluoride and casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) application. The sample included 42 upper premolars extracted for orthodontic reasons. Universal premolar brackets were bonded to the facial surfaces of the teeth that were exposed to a demineralization solution to create artificial white spot lesions, after which the brackets were debonded. The specimens were randomly allocated to three treatment groups (n = 14, each): acidulated phosphate fluoride (APF) gel application group; CPP–ACP paste application group; and control group. pH cycling was conducted to all groups for 14 days. Quantitative measurements were carried out using a spectrophotometer at the following times: before and after the white spot lesions artificially formed and after treating them. All groups showed significant differences in color change before and after treatment. However, there was no significant difference in the color improvement between the APF gel and CPP–ACP paste application groups. Although CPP–ACP application improved the color of the white spot lesions, it did not differ significantly from that of fluoride application.

The Effect of Er:YAG Laser Irradiation Combined With Fluoride Application on the Resistance of Primary and Permanent Dental Enamel to Erosion.

Introduction: Erosion is an important cause of tooth mineral loss. The combined use of lasers and fluoride has been introduced as a novel modality for the prevention of enamel demineralization. This study aimed to assess the effect of Er:YAG laser combined with fluoride application on primary and permanent enamel resistance to erosion. Methods: Eighty enamel specimens of permanent (n=40) and primary (n=40) molars were prepared and randomly assigned to 4 groups: C-control (no pretreatment), F-acidulated phosphate fluoride (APF) gel, FL-APF gel application followed by Er:YAG laser irradiation, and LF-Er:YAG laser irradiation followed by the application of APF gel . The specimens were then submitted to pH cycling using Coca-Cola (pH=2.4). Enamel micro-hardness was measured using the Vickers microhardness tester before pretreatment and after the erosive process. The collected data were analyzed using the Kolmogorov-Smirnov test, two-way ANOVA and repeated measures ANOVA. Results: The micro-hardness of both permanent and primary enamel specimens significantly decreased after the erosive process (P < 0.05). In the permanent enamel specimens, the greatest reduction in micro-hardness was noted in groups C and F, while the least reduction was noted in group FL. However, these differences were not statistically significant (P > 0.05). In the primary enamel specimens, the greatest reduction in micro-hardness was noted in groups C and LF, while the least reduction was noted in group F. These differences were not statistically significant (P > 0.05). Conclusion: Within the limitations of this study, Er:YAG laser irradiation combined with fluoride application could not prevent erosion in permanent and primary enamel during the erosive process.

Estimation and correlation of the amount of fluoride output in urine after the application of fluoride gel and fluoride varnish in children with early childhood caries

Introduction: As all the topical fluorides contain a high concentration of fluorides and it is started at an early age when the swallowing reflexes are not well established, there is every chance the child may ingest a high amount of fluoride. As there are inconsistencies related to the usage of fluoride varnish in children, there is a need to study the toxicological aspects of fluoride varnish. Objectives: The objectives of this study were to estimate the amount of fluoride output through urine after the application of fluoride varnish and gel and to assess the safety levels of the same in early childhood caries (ECC) patients. Methodology: This study was conducted on twenty ECC-rehabilitated children of age group 4–6 years who were divided into two phases. In Phase I, the children were subjected to acidulated phosphate fluoride (APF) gel, and in Phase II, they were subjected to Fluor Protector varnish. In Phase I, the urine samples of each child were collected for the estimation of fluoride level which was considered as the baseline sample. After the application of APF gel, two urine samples were collected at 24 and 48 h for the estimation of fluoride levels. The same children were included in Phase II and were given placebo dentifrice for 7 days before commencing the procedure. The same experiment was repeated after the application of Fluor Protector varnish, and the collected urine samples were subjected for the estimation of fluoride level in laboratory with the use of fluoride ion-specific electrode and a miniature calomel reference electrode coupled to potentiometer. Values were recorded and the urinary fluoride concentration at different time intervals in each group was compared using the Friedman test followed by the Wilcoxon signed-rank test. Results: The mean urinary fluoride concentration in Group 1 at 24 h was 1.09 (standard deviation [SD] = 0.52) and at 48 h 0.74 (SD = 0.44). The mean urinary fluoride concentration in Group 2 at 24 h was 1.18 (SD = 0.65) and at 48 h 0.94 (SD = 0.59). There was a gradual increase in the 24th-h sample of both the groups, which also showed a decline of fluoride concentration at the 48th h. When both the groups were compared, Group 2 showed a marginal increase in fluoride concentration at different intervals of time, which was statistically nonsignificant. Conclusions: Fluor Protector varnish had an increased sustained release of fluoride ions when compared to APF gel, and there was a gradual decrease in the fluoride concentration which suggested that the fluoride concentration was approximating the baseline level (the safety level). The present study has provided a sound basis of recommendation for the safe and effective use of professionally applied fluoride products.

Effect of Acidulated Phosphate Fluoride Gel Application on the Surface Roughness of Resin Sealant

When resin sealant for teeth is exposed to acidulated phosphate fluoride (APF) gel, a commonly used fluoride application agent, its surface roughness can increase, potentially resulting in bacterial adhesion and secondary caries. Therefore, this study analyzed the effect of the application of APF gel on the surface roughness of resin sealants. Thirty-six resin sealant specimens were randomly divided into six groups, which received 1, 2 or 3 applications of APF gel or were soaked in distilled water (aquadest) 1, 2, or 3 times for 30 min. A Mitutoyo SJ201 surface roughness tester was used to measure the mean roughness. Surface roughness was significantly increased after a single gel application, but decreased significantly after two gel applications (p < 0.05). Thus, APF gel reduced resin sealant surface roughness after two or more applications.

Retention Improvement in Fluoride Application with Cold Atmospheric Plasma

This study aimed to apply fluoride formulations to enamel with cold atmospheric plasma (CAP) and analyze the fluoride uptake, retention, and acid resistance quantitatively. Human enamel specimens were divided randomly into 2 groups: group APF1, 1.23% acidulated phosphate fluoride (APF) gel; group APF2, 1.23% APF gel with CAP. Fluoride and CAP were applied to the samples 4 times at 1-wk intervals. The specimens were also stored in artificial saliva for 4 wk to evaluate the retention of fluoride. The fluoride content on the fluoride-treated enamel was measured by an electron probe microanalyzer. To detect the resistance to demineralization, the calcium-to-phosphate ratio of the enamel samples was measured after the application of APF gel with or without CAP, followed by soaking in the demineralization solution. In groups APF1 and APF2, the amount of fluoride detected increased depending on the application frequency, and more fluoride was detected in group APF2 than in group APF1. In the experiment examining the maintenance effect, fluoride was not detected in group APF1, whereas fluoride was detected in group APF2 up to the fourth week. As for the resistance to demineralization, the calcium-to-phosphate ratio of the enamel treated with APF and CAP was higher than that treated with APF alone, and it increased with the frequency of treatment. This study suggests that the combination treatment of CAP and fluoride improves retention of fluoride on the enamel and resistance to demineralization when compared with treatment with fluoride alone.

Introducing mini clinical evaluation exercise for assessing preventive procedure - 1.23% acidulated phosphate fluoride gel application by final year dental students

Introducing mini clinical evaluation exercise for assessing preventive procedure - 1.23% acidulated phosphate fluoride gel application by final year dental students

Effect of 5,000 ppm Fluoride Dentifrice or 1,100 ppm Fluoride Dentifrice Combined with Acidulated Phosphate Fluoride on Caries Lesion Inhibition and Repair

High fluoride dentifrice (FD; 5,000 ppm F) has been recommended to arrest root dentine lesions and to control enamel caries in high-risk patients. Also, standard FD (1,100 ppm F) in combination with professional fluoride application has been recommended to control dentine caries, but the effect of this combination on enamel has been considered modest. Considering the lack of evaluation comparing the use of 5,000 ppm FD (5,000-FD) versus acidulated phosphate fluoride (APF) application combined with 1,100 ppm FD (1,100-FD) on the inhibition and repair of caries lesions in both enamel and dentine, we conducted this in situ, double-blind, crossover study of 3 phases of 14 days. In each phase, 18 volunteers wore palatal appliances containing enamel and root dentine specimens, either sound or carious, to evaluate the effect of the treatments on the inhibition or repair of caries lesions, respectively. The treatments were non-FD (negative control), 5,000-FD, or 1 APF gel application on dental specimens combined with 1,100-FD used twice per day (APF + 1,100-FD). The reduction of demineralization and enhancement of remineralization were assessed by surface and cross-sectional hardness. Fluoride concentration was determined on dental specimens and on the formed biofilm. For enamel, APF + 1,100-FD and 5,000-FD did not differ regarding the inhibition of demineralization and repair of caries lesions. However, for dentine the difference between these treatments was inconclusive because while APF + 1,100-FD was more effective than 5,000-FD in caries lesion reduction and repair, 5,000-FD was more effective than APF + 1,100-FD in the reduction of surface demineralization. Therefore, the findings show that the combination of APF + 1,100-FD is as effective as 5,000-FD in enamel inhibition of demineralization and enhancement of remineralization.

CO2 laser irradiation enhances CaF2 formation and inhibits lesion progression on demineralized dental enamel-in vitro study.

This study evaluated if Carbon dioxide (CO2) (λ 10.6 μm) laser irradiation combined with acidulated phosphate fluoride gel application (APF gel) enhances "CaF2" uptake by demineralized enamel specimens (DES) and inhibits enamel lesion progression. Thus, two studies were conducted and DES were subjected to APF gel combined or not with CO2 laser irradiation (11.3 or 20.0 J/cm(2), 0.4 or 0.7 W) performed before, during, or after APF gel application. In study 1, 165 DES were allocated to 11 groups. Fluoride as "CaF2 like material" formed on enamel was determined in 100 DES (n = 10/group), and the surface morphologies of 50 specimens were evaluated by scanning electron microscopy (SEM) before and after "CaF2" extraction. In study 2, 165 DES (11 groups, n = 15), subjected to the same treatments as in study 1, were further subjected to a pH-cycling model to simulate a high cariogenic challenge. The progression of demineralization in DES was evaluated by cross-sectional microhardness and polarized light microscopy analyses. Laser at 11.3 J/cm(2) applied during APF gel application increased "CaF2" uptake on enamel surface. Laser irradiation and APF gel alone arrested the lesion progression compared with the control (p < 0.05). Areas of melting, fusion, and cracks were observed. CO2 laser irradiation, combined with a single APF application enhanced "CaF2" uptake on enamel surface and a synergistic effect was found. However, regarding the inhibition of caries lesion progression, no synergistic effect could be demonstrated. In conclusion, the results have shown that irradiation with specific laser parameters significantly enhanced CaF2 uptake by demineralized enamel and inhibited lesion progression.

Effects of CO2 laser irradiation combined with fluoride application on the demineralization, mechanical properties, structure, and composition of enamel.

We investigated the effects of CO2 laser irradiation combined with acidulated phosphate fluoride (APF) application on the demineralization of enamel. APF gel was applied to the buccal enamel of human premolars and CO2 laser was applied. After the specimens were immersed in demineralization solution for 72 h, they were subjected to depth-dependent micro-CT and nanoindentation analyses. Micro-X-ray diffraction and X-ray photoelectron spectroscopy were performed to analyze the surfaces. Some surface regions of the enamel in specimens that were laser-irradiated with low output and APF-treated showed significantly higher values of MD and hardness than specimens treated with APF alone. A higher fluoride concentration in the enamel surface was observed in specimens treated with CO2 laser irradiation plus APF gel application. In conclusion, CO2 laser irradiation with low output is preferable to improve acid resistance.

Surface and mineral changes of enamel with different remineralizing agents in conjunction with carbon-dioxide laser.

Aim:The aim of this study was to evaluate the surface/mineral changes on enamel before and after the application of acidulated phosphate fluoride (APF) gel, fluoride enhanced hydroxyapatite gel and propolis in conjunction with carbon-dioxide (CO2) laser.Materials and Methods:Crowns of 40 human maxillary central incisors were collected and were divided into four groups of 10 each: Topical fluoride application only, topical fluoride application followed by CO2 laser irradiation, CO2 laser irradiation followed by topical fluoride application and CO2 laser irradiation before and after topical fluoride application. The 10 crowns in each group was again sectioned into four equal parts of mesio-incisal, disto-incisal, mesio-cervical and disto-cervical sections rendering 40 samples in each group. Each group was again subdivided into four subgroups: Subgroup C - untreated enamel surface (control). Subgroup A - APF gel application, subgroup R - fluoride enhanced hydroxyapatite gel application and subgroup P - propolis application. The surface morphology of the test samples were analyzed by scanning electron microscopy and mineral changes by energy dispersion X-ray spectrophotometer.Results:Total mineral content is maximum in Group 4A (CO2 laser irradiation before and after APF gel application) and calcium/phosphate ratio is highest in Group 4R (CO2 laser irradiation before and after Remin-Pro application). Group 2A (APF gel application followed by CO2 laser irradiation) has the maximum fluoride retention.Conclusion:Laser irradiation of enamel through a topically applied APF gel is effective in the prophylaxis and management of dental caries.

Surface micromorphological changes of glass ionomer following application of 1.23% acidulated phosphate fluoride: a scanning electron microscope study.

The purpose of this study was to evaluate the surface micromorphological changes of conventional glass ionomer cement (GIC) (Fuji II, GC Corporation, Tokyo, Japan) and high strength, high viscosity GIC (Fuji IX GP, GC Corporation) subjected to 1.23% acidulated phosphate fluoride (APF) gel for 4 min. It also evaluated the surface micromorphological changes that occurred in these materials when they were coated with a layer of glass ionomer varnish prior to the application of 1.23% APF gel. A total of 60 uniform glass ionomer cylinders were prepared (30 of each Fuji II and Fuji IX) and stored in distilled water for 48 h, following which they were divided into six groups depending on the surface treatment. Group 1: Fuji II alone, Group 2: Fuji IX alone, Group 3: Fuji II + 1.23% APF gel for 4 min, Group 4: Fuji IX + 1.23% APF gel for 4 min, Group 5: Fuji II + varnish + 1.23% APF gel for 4 min, and Group 6: Fuji IX + varnish + 1.23% APF gel for 4 min. After the required surface treatment had been done, the specimens were mounted, coated, and evaluated under scanning electron microscope. Kruskal-Wallis test applied to compare the level of degradation among the groups subjected to treatment was highly significant (P < 0.001). Mann-Whitney test was applied to test the association between glass ionomer varnish and level of surface degradation and was also statistically significant (P = 0.001). The results indicated that APF gel etched the surface of both Fuji II and Fuji IX. However, Fuji IX showed to possess better resistance to the erosive effect of APF than Fuji II. It was also observed that application of glass ionomer varnish prior to APF gel application protected the glass ionomer from the erosive effect of APF gel. APF gel caused erosive wear of the GICs esp. Fuji II. Hence, it is advisable to avoid the use of APF containing preparations for regular home use especially in children having glass ionomer restoration. If APF gel is indicated or preferred for professional application, it is recommended to apply glass ionomer varnish on the restored teeth prior to the APF gel application.

Effect of Acidulated Phosphate Fluoride Gel Application Time on Enamel Demineralization of Deciduous and Permanent Teeth

Although the effect of acidulated phosphate fluoride gel (APF gel) on caries reduction in permanent teeth is based on evidence, the relevance of the clinical application time is still under debate. Also, the effect of 4- versus 1-min application has not been evaluated in deciduous enamel. In a blind, crossover, in situ study of 14 days, 16 adult volunteers wore palatal appliances containing slabs of human permanent and deciduous enamel. At the beginning of each phase, the slabs were submitted to one of the following treatments: no APF application (negative control); APF gel (1.23% F) application for 1 or 4 min. Biofilm accumulation on the slab surface was allowed and the slabs were subjected eight times a day to 20% sucrose, simulating a high cariogenic challenge condition. On the 15th day of each phase, fluoride retained as CaF₂ and fluorapatite (FAp) was determined on the enamel of the slabs and demineralization was assessed by cross-sectional microhardness. Fluoride as CaF₂ and FAp, formed by APF gel application on the enamel slabs not subjected to the cariogenic challenge, was also determined. APF gel reduced demineralization in both enamel types (p < 0.05), but the difference between 1 and 4 min was not statistically significant (p > 0.05). CaF₂ and FAp formed and retained on deciduous and permanent enamel was significantly higher in APF gel groups (p < 0.05), but no significant difference was found between 1 and 4 min (p > 0.05). The findings suggest that 1 min of APF gel application provides a similar effect on inhibition of demineralization as 4 min, for both permanent and deciduous enamel.

Effects of acidulated phosphate fluoride gel application on surface roughness, gloss and colour of different type resin composites

Objective Application of acidulated phosphate fluoride (APF) gel has been reported to cause deterioration of resin composites. This study investigated the effects of APF gel application on surface roughness, gloss and colour of resin composites. Methods A2-shade resin disks of 2 mm thickness polished with 180-grit and 3000-grit SiC papers were made with Estelite Σ Quick (EQ), Clearfil Majesty (CM) and Beautifil II (B2). Six disks were prepared for each group. APF gel was applied in a 3 mm thickness on the top surface of resin disks and left for 30 min followed by rinsing and ultrasonic washing. This procedure was repeated 4 times. The L* a* b* values, colour difference (Δ E* ab), opacity, surface gloss and roughness of specimens before and after APF application were compared. Data were analysed ANOVA and Fisher's PLSD test with α = 0.05. Results For the 3000-grit polishing groups, the order of influence of APF gel application on colour of resin composites was CM > B2 > EQ. Both in the 180- and 3000-grit polishing groups, colour difference before and after APF gel application was hard to detect (CM and B2) or impossible to detect (EQ) by naked eye. On the other hand, for all the resin composites, the gloss was significantly decreased by APF gel application. APF gel appeared to cause deterioration and dissolution of resin composites used in this study. Significance In this limited study, supra-nano spherical filled Estelite Σ Quick showed the least change on colour, gloss and surface roughness by APF gel application.

Effect of different topical fluoride applications on the surface roughness of a colored compomer

ObjectiveThe aim of this study was to evaluate the effect of neutral sodium fluoride (NNaF) gel and acidulated phosphate fluoride (APF) gel on the surface roughness of colored compomer (Twinky Star), conventional compomer (Compoglass F) and resin-modified glassionomer cement (RMGIC) (Photac-Fil).Material and MethodsA total of 45 standardized disc-shaped specimens were prepared for each material. After 24 h, finishing and polishing of specimens were done with aluminum oxide disc. Surface treatments with topical fluoride agents or distilled water (control) were performed four times, and interspersed with 8 pH cycles, simulating high cariogenic challenges. After the treatment, the surface roughness (Ra) was determined using a profilometer. In each group, specimens with Ra closest to the mean were examined with a scanning electron microscope (SEM) at ×1,000 and ×3,500 magnifications. Two-way ANOVA was used to evaluate Ra measurements, and the differences in Ra values between subgroups for each material and each topical applications were compared by Tukey’s highly significant difference pairwise comparisons.ResultsNo statistically significant difference in Ra between the Twinky Star and Compoglass F was found. However, Photac Fil showed significantly higher Ra than these materials after all surface treatments. There was a general trend of Ra increase from controls to NNaF and APF gels for all materials. SEM observations revealed that the surface micromorphology of Twinky-Star did not differ significantly from that of Compoglass F.ConclusionBoth the compomers and the RMGIC showed significantly higher surface roughness when subjected to APF gel application.

Comparison of remineralization effect of three topical fluoride regimens on enamel initial carious lesions

Some studies have been conducted to evaluate the effect of different topical fluoride regimens on the remineralization of initial carious lesions. This study was conducted to compare the effects of 3 topical fluoride treatments on the surface microhardness, fluoride uptake, and fluorescence lesion area in enamel. Forty-eight bovine teeth were demineralized and subjected to one of the following treatments: (1) no treatment (control), (2) iontophoresis using 2% sodium fluoride solution, (3) 1.23% acidulated phosphate fluoride gel application, and (4) 5% sodium fluoride varnish application. Six persons continuously wore a mandibular removable appliance mounted with eight treated bovine teeth orally for 4 weeks, except while eating, sleeping, and brushing. Microhardness of enamel surfaces was measured using a digital microhardness tester. The fluoride concentration was analyzed using a fluoride electrode, and the fluorescence lesion area was calculated by confocal laser scanning microscopy. No significant differences in the microhardness were observed in response to the 3 fluoride regimens. The highest level of fluoride was observed in the APF gel group. APF gel group also showed significantly reduced fluorescence lesion areas compared to those of the control group. The fluoride regimens showed no difference in surface microhardness; although APF gel showed the best effects in terms of fluoride uptake and decrease in the fluorescence lesion area, its effects were not significantly different from those of fluoride varnish.

Effect of APF gel application time on enamel demineralization and fluoride uptake in situ

This in situ crossover and blind study was conducted to investigate the effect of professional acidulated phosphate fluoride (APF) gel application time on the subsequent inhibition of enamel demineralization. During 3 phases of 28 days each, 15 volunteers wore palatal appliances containing 4 enamel blocks, which were subjected to 3 treatment groups: not treated (control) and pre-treated with APF gel for 1 or 4 min. Dental plaque was allowed to accumulate on the blocks and the appliances were immersed in 10% sucrose solution 3 times a day simulating a cariogenic challenge. After each phase, the blocks were removed to evaluate enamel demineralization and concentration of fluoride (F) remaining after the cariogenic challenge. F formed on enamel was determined in additional enamel blocks subjected only to APF gel application. APF gel was efficient in reducing enamel demineralization (p<0.05), irrespective of the application time (p>0.05). Also, the concentration of the F formed and retained on enamel was significantly higher after APF gel application (p<0.05), but the effect of time of application was not statistically significant (p>0.05). The results suggest that APF application for either 1 or 4 min is equally efficient to increase F concentration in enamel and reduce enamel demineralization.