Assessment of the Effectiveness of Different Fluoride-releasing Bonding Agents on Prevention of Enamel Demineralization around Orthodontic Bracket: An In Vitro Study.

AIM: The aim of the current research was to evaluate the efficacy of different fluoride-releasing bonding products in preventing enamel demineralization around orthodontic brackets by using a scanning electron microscope (SEM). MATERIALS AND METHODS: This research was performed using 80 healthy human premolar teeth that were extracted in course of orthodontic therapy. Until use, the sample premolars were subjected to storage in 0.1% thymol. Each premolar was thereafter cleansed with pumice for 10 seconds. Stainless steel brackets for premolars were employed. The 80 samples were allocated at random to one of the four groups (20 in each) as follows: Group I, control; group II, Transbond Plus color change adhesive; group III, GC Fuji Ortho LC; and group IV, Vitremer. An hour following bonding, all samples were subjected to pH cycling at a temperature of 37°C for a 14-day period. The premolar teeth were assessed below SEM. Analysis was performed with the one-way analysis of variance. Statistical significance was set at a p-value less than 0.05. RESULTS: The extreme area of demineralization was abridged by the use of Transbond™ Plus color change adhesive (108.19 ± 0.68), trailed by GC Fuji Ortho LC (119.24 ± 0.37) use, Vitremer (121.56 ± 0.92) as well as the control group (141.88 ± 1.09) in that order. And there was a statistically significant difference found between the groups (p <0.001). Tukey's honestly significant difference (HSD) was employed in an overall comparison of mean areas of enamel demineralization, which depicted that differences were significant statistically with the exception of group III and group IV. CONCLUSION: The current research came to a conclusion that the Transbond Plus color change adhesive group was more potent in significant inhibition of demineralization areas in comparison to GC Fuji Ortho LC group and Vitremer group. CLINICAL SIGNIFICANCE: In course of fixed orthodontic therapy, demineralization of enamel is an inherent occurrence. Multiple approaches are being continually developed to avoid the formation of white spot lesions (WSLs) that compromise esthetics and cause deprived remineralization that enhances the menace of dental caries. Bonding agents that can release fluorides are thus considered highly efficacious.

Comparative assessment of conventional and light-curable fluoride varnish in the prevention of enamel demineralization during fixed appliance therapy: a split-mouth randomized controlled trial.

Objective: To evaluate the effects of single application of a conventional versus light-curable fluoride varnish (LCFV) on prevention of enamel demineralization during fixed orthodontic treatment over a 4 month period. Design: The research was designed as a split-mouth, randomized control trial (RCT). Methods: Twenty-two patients requiring fixed orthodontic treatment with premolar extractions were included in the RCT. In each patient, two diagonal quadrants (i.e. upper right and lower left, or vice versa) were randomly assigned to receive conventional fluoride varnish or LCFV. After allocation of one intervention, the other diagonal quadrants received the second intervention. At specific time intervals, premolars were extracted and sectioned, and the demineralized lesion was assessed in each group. Main outcome measures: The primary outcome was demineralized enamel lesion depth (DELD) at the end of 45, 90, and 120 days. Randomization: A simple complete randomization list using random allocation rule (restricted randomization) was computer generated to ensure homogeneity of application of conventional or LCFV to each contralateral quadrant in a split-mouth design. Allocation concealment was not employed. Blinding: Blinding was done only for outcome assessor because of clinical limitations. Results: Twenty-two patients with 88 teeth were enrolled in the trial. After excluding the drop-outs, primary analysis was performed on 66 teeth distributed among two interventional groups. Mean difference between DELD among two groups was 36.6 µm [95 per cent confidence interval (CI) 34.61-38.55] and 58.5 µm [95 per cent confidence interval (CI) 55.65-61.43] at 90 and 120 days, respectively. Cluster level analysis performed by Paired t-test showed that DELD was significantly higher (P < 0.001) in the conventional fluoride varnish group at the end of 90 and 120 days as compared to LCFV group. No adverse effect was observed in any patient. Limitations: Being a histologic study, the role of fluoride varnish could be assessed only for 4 months. Conclusion: The result of this study indicate that single application of LCFV (Clinpro™ XT) can prevent enamel demineralization for longer duration (for up to 4 months) of time as compared to conventional fluoride varnish (Duraphat™, 45 days) during fixed appliance therapy. Registration: The trial was registered retrospectively in the Clinical Trial Registry-India, number CTRI/2016/09/007232.

Nanoscratch testing for the assessment of enamel demineralization under conditions simulating wine erosion.

BACKGROUND: Erosive tooth wear and dentinal hypersensitivity are common problems affecting professional wine tasters. By using nanoscratch testing, the aim of this in vitro study was to assess enamel softening under conditions simulating 10 one-minute episodes of wine erosion. METHODS: Ten enamel specimens were bathed in artificial saliva for 2 hours before being eroded for 10 episodes, with each episode comprising one minute of wine erosion followed by one minute of remineralization in artificial saliva. Nanoscratches were placed with a spherical tip (20 µm radius) in a nanoindenter under a load of 100 mN at baseline (stage 1), after a one-erosion episode (stage 2) and after 10-erosion episodes (stage 3). RESULTS: There were significant effects of erosion stages on both scratch depth (p<0.001) and surface roughness (p<0.001). Post hoc tests showed significant differences in both scratch depths and surface roughness between stages 1 and 3 (p<0.001), and between stages 2 and 3 (p<0.01). CONCLUSIONS: Enamel softening occurs at an early stage of wine tasting, emphasizing the need to implement early preventive strategies in professional wine tasters. Further research elucidating the fundamental mechanisms involved in early stages of erosion has the potential to lead to development of more effective preventive strategies.

In situ assessment of effects of the bromide- and fluoride-incorporating adhesive systems on biofilm and secondary caries.

AIM: This in situ study assessed the effects of adhesive systems containing or not fluoride and/or the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) on the microbiological composition of dental biofilm and enamel demineralization. MATERIALS AND METHODS: During two phases of 14 days, ten volunteers wore intraoral palatal appliances containing two slabs of human enamel according to a double-blind, crossover design. The slabs were randomly restored using a composite resin and one of the following adhesive systems: All-Bond SE(TM) (self-etch, fluoride/MDPB free adhesive, AB) and Clearfl Protect Bond (self-etch containing fluoride and MDPB adhesive, CB). The biofilm formed on the slabs was analyzed with regard to total and mutans streptococci and lactobacilli counts. Demineralization represented by integrated area of hardness × lesion depth Delta S ( ΔS) was determined on enamel by analysis of cross-sectional microhardness, at 20 and 70 µm from the restoration margin. Data were analyzed by ANOVA. RESULTS: No statistically significant difference was found either in enamel demineralization or in the microbiological composition of dental biofilm. CONCLUSION: All adhesive systems containing or not fluoride and/or MDPB tested were unable to inhibit secondary caries in the in situ model used in the present research.

Changing concepts in cariology: forty years on.

UNLABELLED: The caries lesion is a sign or symptom resulting from numerous pH fluctuations in biofilms on teeth. The lesion may or may not progress and lesion progression can be controlled, slowed down or arrested. Control of the biofilm is the treatment of caries, the most important measure being to disturb the biofilm mechanically using a fluoride-containing toothpaste. The informed patient controls caries and the role of the dental professional is to advise how this should be done. This is the non-operative treatment of caries and it is worthy of payment. It should be mandatory as part of any operative treatment to ensure that the patient understands, and is able to perform, adequate plaque control. CLINICAL RELEVANCE: It is very unfortunate that the current remuneration scheme (Unit of Dental Activity) in Health Service practice in England and Wales prevents practitioners adopting a modern biological approach to caries control.

Etiología de las opacidades severas del esmalte: una evaluación basada en un estudio prospectivo médico y social en 17000 niños / Aetiology of severe demarcated enamel opacities: an evaluation based on prospective medical and social data from 17000 children

Durante los años 70s, los odontólogos describieron una prevalencia creciente de un nuevo tipo de alteración en el esmalte. Este era muy específico, con áreas de demarcado esmalte hipomineralizado y se encontraba en su mayoría en los primeros molares permanentes y en los incisivos. Diferentes estudios trataron de relelar la etiología de estas alteraciones, pero hasta ahora no se han encontrado factores claramente relacionados. El propósito del presente trabajo fue evaluar los factores etiológicos de las opacidades demarcadamente severas (OSD) en los primeros molares permanentes en una gran cohorte de niños incluidos en el proyecto "Todos los niños del sudeste de Suecia" (ABIS). Se llevó a cabo un estudio prospectivo de los niños de 5 condados suecos nacidos entre el 1º de octubre de 1997 y el 1 de octubre de 1999, un total de 17000 niños que fueron seguidos desde su nacimiento y fueron registrados un gran número de factores sobre nutrición, enfermedades, medicación, infecciones, situación social, etc. Con la ayuda de 89 clínicas del Servicio Dental Público, en la misma área, se realizaron exámenes preliminares de los niños nacidos entre octubre 1º de 1997 y octubre 1º de 1999. Se analizaron 595 niños con opacidades severamente marcadas (OSD) en los primeros molares. Estos niños, y un grupo control de 1200 niños seleccionados al azar fueron luego invitados para ser examinados por odontopediatras. En estos exámenes se identificaron 224 casos severos, como así también 253 niños sin ninguna alteración en el esmalte. Fueron analizados estos dos grupos. No hubo ninguna correlación entre OSD y las variables del banco de datos del ABIS. Los análisis muestran que no existe asociación entre OSD y datos pre, peri y neonatales. Sin embargo, hemos encontrado una asociación positiva entre OSD y el alimento a pecho por más de 6 meses.

Orthodontic treatment-related white spot lesions: a 14-year prospective quantitative follow-up, including bonding material assessment.

INTRODUCTION: White spots (WS) related to orthodontic treatment are severe cariologic and cosmetic complications, but they are shown to be partially reduced by remineralization or abrasion in short-term follow-ups. In this prospective study, we quantitatively analyzed changes in WS in general and in treatment-related white spot lesions (WSL) during orthodontic treatment and at a 12-year follow-up after treatment. In addition, we quantitatively compared the effects of an acrylic bonding material vs a glass ionomer cement (GIC) on WSL. METHODS: Sum areas of WS and WSL were calculated on scans of standardized photos of the vestibular surfaces of 4 teeth in consecutive orthodontic patients (median treatment time, 1.7 years) bonded with the 2 materials in a split-mouth design. Comparisons were made in 59 patients before treatment (BF), at debonding (T0), at 1 year (T1), and at 2 years (T2), and in 30 patients at a 12-year follow-up (T3) with the Friedman test followed by pairwise comparisons with the Wilcoxon matched-pairs signed rank test. Differences of the effects of acrylic vs GIC on the sum areas of WSL were tested for each observation period with the Mann-Whitney U test. RESULTS: Increases in the sum areas of WS and WSL from BF to T0 (P <0.001) were followed by significant decreases at T1 (P <0.001) and T2 (P <0.01 for WS; P <0.001 for WSL). Significant changes were also found in the sum areas for WS at T3 compared with T2 (P <0.01), but not for WSL (P = 0.328). The sum areas of WS and WSL at T3 did not return to BF levels (P <0.001). Sum areas of WSL were higher for surfaces bonded with acrylic compared with GIC for each observation period from BF to T2 (P >0.001), and from T2 to T3 (P >0.05). CONCLUSIONS: Although significantly reduced during the 12-year follow-up and significantly lower with the GIC than the acrylic material at bonding, WSL are a cariologic and cosmetic problem for many orthodontic patients.

Non-destructive assessment of inhibition of demineralization in dental enamel irradiated by a lambda=9.3-microm CO2 laser at ablative irradiation intensities with PS-OCT.

BACKGROUND AND OBJECTIVE: Polarization sensitive optical coherence tomography (PS-OCT) has great promise for the non-destructive assessment of the efficacy of anti-caries agents such as fluoride and thermal laser treatments on enamel surfaces. The purpose of this study was to demonstrate that PS-OCT can be used to measure demineralization in craters/incisions prepared in enamel by a CO(2) laser operating at the high irradiation intensities required for cavity preparations. MATERIALS AND METHODS: Incisions in bovine enamel surfaces were produced by a CO(2) laser used with a water spray. The laser was operated at lambda=9.3 microm with a pulse duration of 15 micros and an incident fluence of 20 J/cm(2). The laser treatments were also combined with topical fluoride treatments. A PS-OCT system operating at 1,310 nm was used to acquire polarization resolved images of six areas including sound and laser-ablated+topical fluoride treated zones on each sample. After imaging the teeth, they were sectioned and the thin sections were examined with polarized light microscopy (PLM) and transverse microradiography (TMR). The integrated reflectivity and lesion depth derived from the PS-OCT scans, the integrated mineral loss and depth measured using TMR and the lesion depth measured with PLM were acquired for each area on the fifteen samples for comparison. RESULTS: The integrated reflectivity and depth in the areas treated by the laser and fluoride were significantly lower (P<0.05) than for the untreated enamel. Similar results were observed for TMR and PLM. CONCLUSIONS: These results suggest that PS-OCT has great potential for the non-destructive "in vivo" assessment of the inhibition of demineralization by lasers at ablative irradiation intensities with and without topical fluoride application.

Management of postorthodontic demineralized white lesions with microabrasion: a quantitative assessment.

INTRODUCTION: The aim of this study was to quantify changes in postorthodontic demineralized enamel lesion surface areas after microabrasion. METHOD: The study group comprised 8 orthodontic patients (mean age,17.3 years) with multiple decalcified enamel lesions after fixed orthodontic therapy. Two demineralized areas were randomly selected for interventive treatment in each patient. Microabrasion was undertaken on these lesions by using a well-accepted 18% hydrochloric acid and pumice technique. Standardized intraoral images were taken of the lesions before and immediately after microabrasion. Image-processing software was used to quantify (mm2) the visible areas of the demineralized lesions before and after microabrasion. The total labial surface area of each tooth was also determined, and the area affected by demineralization was expressed as a percentage of total tooth surface. Images were reanalyzed a month later to determine the repeatability of the method. RESULTS: Microabrasion significantly reduced visible enamel demineralization (P < .001, paired t test). The mean reduction in lesion size after treatment was 83% (SD, 8.2%; range, 61%-92%). The quantification methodology was found to be highly repeatable with an intraclass correlation coefficient of 0.98. CONCLUSIONS: Microabrasion is an effective treatment approach for the cosmetic improvement of long-standing postorthodontic demineralized enamel lesions.

Assessment of the effect of selected snack foods on the remineralization/demineralization of enamel and dentin.

This study utilized volunteer subjects to examine caries-like lesions for remineralization and demineralization patterns in dentin and enamel when nine different snack foods were eaten between meals. Caries progression was observed in enamel and dentin when apple juice, a cola beverage, and sweetened (strawberry) yogurt were consumed as snacks. Remineralization of enamel was observed when cheddar cheese, skim milk, 2% milk, whole milk, chocolate milk, and orange juice were used as between meal snacks. Dairy products, with the exception of the sweetened yogurt, generally reduced the amount of demineralization produced in dentin. This study helps establish a scientific basis for appropriate between-meal snacks for patients who are concerned about their dietary habits as a part of their overall preventive oral health plan.

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

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

Formation of phosphate-containing calcium fluoride at the expense of enamel, hydroxyapatite and fluorapatite.

During the caries process complex reactions involving calcium, phosphate, hydrogen and fluoride ions as main species take place. In this study the precipitation and dissolution reactions occurring in suspensions of enamel, hydroxyapatite (HAP) and fluorapatite (FAP) on addition of fluoride were investigated under well-defined conditions. pH and pF were monitored; calcium and phosphate concentrations were measured at selected times; the solid phases were examined by infra-red, X-ray diffraction and transmission electron microscopy. Precipitation of phosphate-containing calcium fluoride crystals, CaF2(P), can cause severe reduction in the calcium ion concentration and release of hydrogen ions from the precipitated phosphate. These reactions result in considerable dissolution of enamel, HAP and even of FAP. More of the added mineral dissolves with 50 mmol/l fluoride than with 10 mmol/l fluoride, mainly due to the greater reduction in calcium ion concentration. This work shows that phosphate-containing calcium fluoride is most likely an important compound to be considered in the caries process.