Topical Fluoride Treatment Research Articles

Effect of topical fluoride agents on the morphologic characteristics and composition of resin composite restorative materials

Statement of problem. The high reactivity of fluoride agents used in topical fluoride treatments have raised important questions on their potential adverse effects on restorative materials. Purpose. The purpose of this study was to evaluate the effect of topical fluoride agents used for office or home treatments on the surface morphologic characteristics and composition of composite restoratives. Material and methods. The fluorides used were Act, Phosflur, Gel II, Prevident, Stop, Butler APF, Nupro, and Omni Gel & Rinse. The composites tested were Brilliant DI, Heliomolar Ro, Herculite XRV, and P-50. The pH of the fluorides was measured as received and after dilution with water at a 1:3 volume ratio. The composites were subjected to the fluoride treatments until the total number of applications simulated the equivalent of 4 years under treatment. The changes induced on the surface morphologic features and composition of the restoratives were assessed by multiple internal reflectance Fourier transform infrared spectroscopy, scanning electron microscopy, and x-ray microanalysis. Results. All fluorides showed an acidic pH that was not significantly changed after dilution, except Stop, which exhibited a significant pH reduction. All fluorides increased the amount of loosely bound water in the composite matrix. Butler APF gel was the most aggressive for Brilliant DI and Herculite XRV, leading to excessive surface degradation, porosity, destruction of the filler-matrix interface, filler dissolution, and debonding. A reduction in the extent of remaining C = C bonds was observed in Herculite XRV after Butler APF treatment; Phosflur, Gel II, and Prevident had a milder effect. Treatment of Brilliant Dl and Herculite XRV with Omni Gel & Rinse resulted in the formation of a stable precipitation layer rich in barium, phosphorus, tin, oxygen, and fluoride. P-50 was severely affected at the resin-matrix interface after Stop treatment, whereas Omni Gel & Rinse induced fewer surface changes. Heliomolar Ro was the least affected restorative regardless of the type of fluoride used. (J Prosthet Dent 1997;77:405-13.)

CASE PLANNING AND MANAGEMENT ACCORDING TO CARIES RISK ASSESSMENT

Ultimately, the dentist's role is to guide children through their growth and development free of disease. The dentist must recognize each child's unique susceptibility to caries and each parent's interest, competency, and accomplishment in controlling this disease. With this recognition, it is possible to tailor the frequency and content of dental visits necessary to maintain a child caries-free. Similarly, the frequency of examinations, office topical fluoride treatments, radiographs, and other diagnostic or preventive interventions depends upon the dentist's assessment of how intense professional efforts need to be to help parents maintain their children in health. Goldman and Burket summarized the relationship between science and practice and detailed the responsibilities of clinicians with the following words: "The practice of dentistry is an art in which the teachings of dental science are put to their practical application. A patient visits the dentist for consultation on the state of health of the dentition, with the expectation that everything possible will be done not only to repair or help heal by therapeutic correction any disease present but also to prevent disease from occurring, if possible." Treating caries at the level of the disease process to prevent its expression, progression, and ultimate dental destruction is the highest calling and deepest challenge facing dentists who care for young children. Techniques including risk assessment, triage, tailored care, and thoughtful treatment grounded in dental and behavioral science have put that goal within reach of dentists and parents to the great benefit of children.

フッ化物歯面塗布法に関する研究 塗布要領の再検討 第ＩＩ報

This study was designed to revalue topical fluoride treatment time and the time to refrain from rinsing, eating or drinking following a professional application.In order to investigate the application time, human enamel powder was given a topical fluoride application treatment with APF solution (pH 3.6, F-: 9, 000ppm) for 0, 1, 2, 3, 4, 6 and 8min. We compared fluoride uptake, Ca/P molar ratio and acid resistance test between all fluoride groups and the control.The fluoride concentrations in powder were similar in all groups of 3min or more, and were not statistically different in each group. After washing with 1 M KOH solution, fluoride concentration was decreased in all groups. Although in the 4min group some fluoride remained, all other fluoride groups proved not to be statistically different from each other in treatment time.In all groups, after treatment with fluoride, Ca/P molar ratio was increased significantly, suggesting the production of CaF2 in the enamel powder.The acid resistance test proved that release of calcium was inhibited in all fluoride groups both after treatment and after washing with 1 M KOH solution, though they showed a little difference depending on the demineralization time. All fluoride groups had the same or more acid resistance than the 4min group.To investigate the time for refraining from rinsing, eating or drinking, we measured the fluoride dissolved in water when the enamel powder treated for 4min with APF was immersed with or without stirring for 24h. When stirred, dissolved fluoride suddenly increased in all groups. We could not prove statistical difference in dissolved fluoride in the groups which were stirred directly after treatment, after 10, 20 and 30min.These findings suggested that the application time can be shortened to 4min and the time for refraining from rinsing, eating or drinking can be shortened to 30min.

Study on hypomineralized areas in hamster molars.

Hypomineralized area (HMA) scores were determined for hamster molars during tooth maturation and fluoride treatment. It was found that the molars were maturing until the animals were 45 days old, but from 45 to 74 days of age the HMA scores remained constant. Fluoride treatment decreased the HMA score. The group with the lowest HMA score was fed a cariogenic diet, inoculated with Streptococcus mutans and received topical fluoride treatment.

フッ化物歯面塗布法に関する研究 塗布要領の再検討 第Ｉ報

This study was designed to revalue topical fluoride treatment time and the time to refrain from rinsing, eating or drinking following a professional application.In order to investigate the application time, human enamel powder was given a topical fluoride application treatment with APF solution (pH 3.6, F-: 9, 000ppm) for 0, 1, 2, 3, 4, 6 and 8min. We compared fluoride uptake, Ca/P molar ratio and acid resistance test between all fluoride groups and the control.The fluoride concentrations in powder were similar in all groups of 3min or more, and were not statistically different in each group. After washing with 1 M KOH solution, fluoride concentration was decreased in all groups. Although in the 4min group some fluoride remained, all other fluoride groups proved not to be statistically different from each other in treatment time.In all groups, after treatment with fluoride, Ca/P molar ratio was increased significantly, suggesting the production of CaF2 in the enamel powder.The acid resistance test proved that release of calcium was inhibited in all fluoride groups both after treatment and after washing with 1 M KOH solution, though they showed a little difference depending on the demineralization time. All fluoride groups had the same or more acid resistance than the 4min group.To investigate the time for refraining from rinsing, eating or drinking, we measured the fluoride dissolved in water when the enamel powder treated for 4min with APF was immersed with or without stirring for 24h. When stirred, dissolved fluoride suddenly increased in all groups. We could not prove statistical difference in dissolved fluoride in the groups which were stirred directly after treatment, after 10, 20 and 30min.These findings suggested that the application time can be shortened to 4min and the time for refraining from rinsing, eating or drinking can be shortened to 30min.

The effects of artificial saliva and topical fluoride treatments on the degradation of the elastic properties of orthodontic chains.

The effect of artificial saliva and topical fluoride treatments on the force relaxation and change in force delivery by three brands of elastomeric chains over a 4 week period was studied. The effect of storage in air and in the different test media on the distraction to achieve forces of 150g and 300g was determined for the chains. The effect of the test media on load relaxation of the chains was also examined. Elastomeric chains exhibit good elastic behavior when distracted to an initial force of less than 300g. When forces exceeded 300g, permanent deformation occurred and the force delivery was less predictable. Exposure to artificial saliva and topical fluoride affected the elastic properties of the elastomeric chains and increased the distraction required to deliver both the 150g and 300g force. The increase in distraction for a force of 150g, however, was relatively small and probably insignificant in the clinical setting. The distraction required to produce 300g was significantly larger and appeared to be clinically significant. Pre-stretching the elastomeric chains by 100% of their initial length was not found to be advantageous in terms of the load relaxation behavior. There was less load relaxation found in chains that were immersed in distilled water and Acidulated Phosphate Fluoride than in chains exposed only to air.

Effects of pH and Calcium on Hydrolysis of Na2SiF6and Na2SnF6

In the present work, hydrolysis reactions of sodium hexafluorosilicate (Na2SiF6) and sodium hexafluorostannate (Na2SnF6) were studied at various combinations of pH and calcium ion (Ca2+) concentrations using a quasi-constant composition titration method. Under high concentrations of hydrogen ion (H+) and Ca2+, the promoting effect of Ca2+ on the hydrolysis of Na2SiF6 was stronger than the inhibition effect of H+. However, the inhibition effect of H+ on the hydrolysis of Na2SnF6 was stronger than the promoting effect of Ca2+. Na2SiF6 and Na2SnF6 were found to have hydrolysis properties that may make them suitable for use with an acidic calcium phosphate solution in a topical fluoride treatment which forms dicalcium phosphate dihydrate as an intermediate.

Comparison between Evaluation Methods for the Anti-Caries Efficacy of Monofluorophosphate-Containing Dentifrices

A comparison is described of three methods of preclinical assessment of potential anti-caries efficacy for topical fluoride treatments. Methods are compared using dentifrices containing 1,000, 1,500 and 2,500 ppm F as sodium monofluorophosphate (SMFP). These formulations have been shown elsewhere to give a statistically significant dose response of increasing anti-caries efficacy [Stephen et al., 1988]. An in situ enamel insert model, oral fluoride pharmacokinetics and F uptake to demineralised enamel are all shown to correlate with clinical efficacy for the test dentifrices studied.

Tooth-bound Fluoride and Dental Caries

The cariostatic effects of tooth-bound fluoride reported in the recent literature are reviewed. Several treatment procedures which can increase the tooth-bound fluoride content are described. Based on this information, it is suggested that effectiveness of currently used topical fluoride treatments may be significantly increased by (1) including in the regimen a dicalcium-phosphate-dihydrate-forming treatment so that a portion of the labile fluoride is re-incorporated as tooth-bound fluoride, and (2) employing application methods which ensure the effective delivery of treatment agents to the fissures, and to approximal and cervical surfaces, where most caries occurs.

Fluoride acquisition on and in human enamel during topical application in vitro.

Fluoride acquisition during topical fluoride treatment was studied after different time intervals, at different concentrations and at different pH. The effects of pretreating the enamel with Ca++, and of pre-etching were also tested. Four experimental groups of repeated measures design were established. Chemical assessments were made of the amounts of fluoride formed on (as alkali soluble fluoride, i.e., calcium fluoride) and in enamel (as firmly bound fluoride). The depositions on enamel were also demonstrated by SEM. The amounts of alkali soluble fluoride on enamel increased with time, concentration, pH-decrease and calcium availability. The time of exposure seemed to be the major factor. The amounts of fluoride deposited on enamel outranged by far (greater than 70%) the amounts of fluoride acquired in the enamel. The formation of alkali soluble fluoride on enamel is probably limited by the availability of calcium ions. It is suggested that the fluoride on enamel may protect the enamel surface and serve as a reservoir of fluoride.

Effect of a preventive program on dental caries and mutans streptococci in Polish schoolchildren.

The effect of a preventive program was studied in Polish schoolchildren. The study was carried out in a group of 133 children, aged 10-12 yr, divided into a test and a control group. Children in the test group were initially treated with temporary restorations and were then given oral health education and preventive treatment by a specially trained chairside assistant. The preventive treatment included prophylaxis and topical fluoride treatment and was carried out at least 10 times a year. The mean 3-yr DFS increment was 1.7 in the test and 10.9 in the control group. The salivary counts of mutans streptococci were similar in test and control group at baseline and after 1 and 2 yr. At the examination after 3 yr, a difference was established between the two groups.

Effect of topical fluoride treatments on fluoride distribution during in vitro caries-like lesion formation.

Tooth sections were treated in vitro for 4 min with APF, SnF2, or received no treatment. Each treatment group then received washes of KOH, (24 h), an inorganic solution (24 h), or DDH2O (2 min) and were placed into dialyzed 15% w/v gel (pH 4.3) containing 0.15 mM hydroxyapatite, but no fluoride (less than 0.02 ppm F). Adjacent nontreated sound enamel acted as the control. Lesion microdissection, after 2 weeks exposure to the acidified gel, revealed an inverse relationship between lesion body fluoride concentration and lesion depth. The lesion depth was smallest, and the lesion body fluoride concentration was greatest in both fluoride-treated groups after a 2-min DDH2O wash, a 24-hour inorganic wash, and a 24-hour KOH wash, respectively. These data support the theory that the progress of carious lesions is related to the fluoride concentration in the lesion and that the fluoride concentration in the lesion is related to the acquired fluoride concentration in sound enamel.

Topical Fluorides: A Discussion of Risks and Benefits

Inadvertent ingestion of fluoride from topical procedures poses the risk of dental fluorosis in age-susceptible users. This risk can be minimized for mouthrinsing by restricting it to those above the age-susceptible limit. Operators administering topical fluoride treatments can take practical precautions that have been shown to reduce the amount of fluoride retained and, thus, reduce ingestion. Clinical and epidemiological studies have failed to establish that dentifrice ingestion by young children constitutes a serious fluorosis risk. Discussion of risk must consider the effect of perceived risks upon the public.

Combined effect of systemic and topical fluoride treatments on human deciduous teeth--case studies.

Forty-six deciduous teeth from caries-free children who had been exposed to systemic fluoride tablet treatment (0.5–1 mg F––/day) from 3 months prenatally to 7 years of age were examined hi

The effect of topical fluoride treatment on enamel fluoride uptake and the tensile bond strength of an orthodontic bonding resin

Enamel demineralization occurring adjacent to directly bonded orthodontic attachments is of great concern to orthodontists. The topical application of fluorides to enamel surfaces before acid etching and the bonding of the attachments is not recommended by many investigators. The objective of this study was to determine the enamel fluoride acquired from various topical fluoride agents and to determine the effect of the acquired fluoride on the tensile bond strength of an orthodontic bonding system. Fifty extracted maxillary central incisors were mounted in cups and the facial surfaces of the crowns were polished on 600-grit silicon carbide paper. Enamel microbiopsies were performed just off the midpoint of each tooth. Ten teeth served as controls and received no topical fluoride treatment, while a similar number were treated with either APF, SnF2, Duraphat, or Fluor Protector. The teeth were suspended in synthetic saliva 4 minutes after fluoride application. The topical fluoride agents were removed after 24 hours and the teeth were again suspended in synthetic saliva at 37 °C for 7 days. Enamel biopsies were again performed just off the midpoint of each tooth on the side not previously biopsied. The enamel surfaces were etched for 1 minute and the tensile bond strength of Concise orthodontic bonding system to the etched enamel surfaces was determined. The enamel surfaces acquired significantly different amounts of fluoride from the topical fluoride agents, but the bond strengths to these surfaces were not significantly different. The results of this in vitro study suggest that the application of topical fluoride agents to enamel surfaces 7 days before the bonding of orthodontic attachments will not have an adverse effect on bond strength.

Effects of suctioning devices on oral fluoride retention

This study examined the effectiveness of suctioning devices in reducing oral fluoride retention after professional 4-minute applications of a 1.23% fluoride gel. The value of patient expectoration was also evaluated in the child subjects. The suction devices were statistically significant adjuncts in reducing oral-retained fluoride in all cases; however, the oral-retained fluoride doses after the suctioning procedures were still distinct in both adults (10.3 +/- 2.3 mg) and children (7.7 +/- 1.0 mg). These amounts of oral-retained fluoride would result in substantial elevations in body fluid fluoride concentrations. One minute of expectoration after the suctioning procedures in children was a statistically significant method of further reducing oral fluoride retention to a clinically acceptable level (1.6 +/- 0.5 mg). We recommend that suction devices be used during topical fluoride treatments, but most importantly that the patients be requested to expectorate thoroughly after topical treatment.

Influence of social class and fluoridation on child dental health.

In this study in oral epidemiology, officially collected statistics are presented which show that, 15 yr after fluoridation commenced in Auckland, New Zealand, there was still a significant correlation between dental health of children and their social class. They also show that treatment levels have continued to decline in both fluoridated and unfluoridated areas, and are related to social class factors rather than to the presence or absence of water fluoridation. In the unfluoridated areas all the children, and in the fluoridated areas only selected children, had received regular topical fluoride treatments. In both areas the use of fluoride tooth-pastes and oral hygiene had been encouraged. When the socioeconomic variable is allowed for, child dental health appears to be better in the unfluoridated areas.

Diagnosis and treatment of acute fluoride toxicity

The literature has shown overwhelmingly that fluoride used for dental prophylaxis presents minimal risks if used appropriately. However, there is an increasing potential for ingestion of toxic doses of fluoride because of the increasing use of pleasant-tasting fluoride products. The ADA has recommended that no more than 120 mg fluoride (264 mg NaF) be dispensed at any one time. As with any medication, fluoride preparations should be prescribed in child-resistant containers, and patients or parents (or both) should be instructed as to the proper daily treatment regimens and the potential for toxic overdoses. Possibly the greatest risk of fluoride intoxication relates to the concentrated fluoride preparations used for professionally applied fluoride treatment (Table 3). Therefore, patients receiving professional topical fluoride treatments should have well-fitting trays with the minimal amount of fluoride necessary to contact the teeth. These patients should be provided with a saliva ejection system, and they should never be left unobserved during the topical application. Health professionals should be aware of the potential toxic effects of fluoride in addition to the well-known caries preventive effects. It is necessary to know how to calculate the amount of fluoride ingested and the emergency treatment recommended to prevent toxic effects in suspected overdose cases.

Stannous fluoride treatment of acid-etched caries-like lesions of enamel: A scanning electron microscopic study

Although fluoride levels become elevated in sound enamel following a topical fluoride treatment, the caries-preventive effect of fluoride is thought to be due primarily to the role of fluoride in remineralization of clinically undetectable enamel lesions and hypomineralized enamel. During lesion formation, redistribution of fluoride from the enamel surface to the subsurface demineralized enamel occurs. This results in a surface zone with a relatively low fluoride content. In order to maintain an intact surface zone over a carious lesion, it may be necessary to replenish the fluoride levels with an exogenous fluoride source. By acid-etching the lesion surface, a more reactive surface is made available for fluoride interaction. In addition, porosities and etching patterns may be created, allowing for bonding of a caries-resistant resin material to the lesion surface. The purpose of this study was to determine the integrity of the caries-like lesion surface following acid-etching and subsequent stannous fluoride treatment (SnF2).

Oral fluoride retention following various topical application techniques in children.

Eight child volunteers received routine APF gel topical fluoride applications using four different application techniques. Each child received a total of four topical fluoride applications, and all applications were separated by at least one wk. The amounts of fluoride applied, recovered from the mouth, and retained in the mouth were calculated for each treatment. Tray systems with some form of absorptive liner resulted in significantly less oral-retained fluoride after the four-minute application procedure (p less than .01). The value of patient expectoration following topical fluoride treatment was also evaluated, and was a significant adjunct in reducing the net oral-retained fluoride dose in each instance (p less than .01).